title: Highlights from the NA60 experiment

abstract:
  The NA60 experiment is a fixed-target experiment at the CERN SPS. It has
measured the dimuon yield in Indium--Indium collisions with an In beam of 158
AGeV/c and in p-A collisions with a proton beam of 400 and 158 AGeV/c. The
results allow to address three important physics topics, namely the study of
the rho spectral function in nuclear collisions, the clarification of the
origin of the dimuon excess measured by NA50 in the intermediate mass range,
and the J/psi suppression pattern in a collision system different from Pb-Pb.
An overview of these results will be given in this paper.


title: Renormalized Quantum Yang-Mills Fields in Curved Spacetime

abstract:
  We present a proof that quantum Yang-Mills theory can be consistently defined
as a renormalized, perturbative quantum field theory on an arbitrary globally
hyperbolic curved, Lorentzian spacetime. To this end, we construct the
non-commutative algebra of observables, in the sense of formal power series, as
well as a space of corresponding quantum states. The algebra contains all gauge
invariant, renormalized, interacting quantum field operators (polynomials in
the field strength and its derivatives), and all their relations such as
commutation relations or operator product expansion. It can be viewed as a
deformation quantization of the Poisson algebra of classical Yang-Mills theory
equipped with the Peierls bracket. The algebra is constructed as the cohomology
of an auxiliary algebra describing a gauge fixed theory with ghosts and
anti-fields. A key technical difficulty is to establish a suitable hierarchy of
Ward identities at the renormalized level that ensure conservation of the
interacting BRST-current, and that the interacting BRST-charge is nilpotent.
The algebra of physical interacting field observables is obtained as the
cohomology of this charge. As a consequence of our constructions, we can prove
that the operator product expansion closes on the space of gauge invariant
operators. Similarly, the renormalization group flow is proved not to leave the
space of gauge invariant operators.


title: Hall effects in Bose-Einstein condensates in a rotating optical lattice

abstract:
  Using the Kubo formalism, we demonstrate fractional quantum Hall features in
a rotating Bose-Einstein condensate in a co-rotating two-dimensional optical
lattice. The co-rotating lattice and trap potential allow for an effective
magnetic field and compensation of the centrifugal potential. Fractional
quantum Hall features are seen for the single-particle system and for few
strongly interacting many-particle systems.


title: A functional limit theorem for a 2D-random walk with dependent marginals

abstract:
  We prove a non-standard functional limit theorem for a two dimensional simple
random walk on some randomly oriented lattices. This random walk, already known
to be transient, has different horizontal and vertical fluctuations leading to
different normalizations in the functional limit theorem, with a non-Gaussian
horizontal behavior. We also prove that the horizontal and vertical components
are not asymptotically independent.


title:
Optimal Separable Algorithms to Compute the Reverse Euclidean Distance
  Transformation and Discrete Medial Axis in Arbitrary Dimension

abstract:
  In binary images, the distance transformation (DT) and the geometrical
skeleton extraction are classic tools for shape analysis. In this paper, we
present time optimal algorithms to solve the reverse Euclidean distance
transformation and the reversible medial axis extraction problems for
$d$-dimensional images. We also present a $d$-dimensional medial axis filtering
process that allows us to control the quality of the reconstructed shape.


title:
Multiuser detection in a dynamic environment Part I: User identification
  and data detection

abstract:
  In random-access communication systems, the number of active users varies
with time, and has considerable bearing on receiver's performance. Thus,
techniques aimed at identifying not only the information transmitted, but also
that number, play a central role in those systems. An example of application of
these techniques can be found in multiuser detection (MUD). In typical MUD
analyses, receivers are based on the assumption that the number of active users
is constant and known at the receiver, and coincides with the maximum number of
users entitled to access the system. This assumption is often overly
pessimistic, since many users might be inactive at any given time, and
detection under the assumption of a number of users larger than the real one
may impair performance.
  The main goal of this paper is to introduce a general approach to the problem
of identifying active users and estimating their parameters and data in a
random-access system where users are continuously entering and leaving the
system. The tool whose use we advocate is Random-Set Theory: applying this, we
derive optimum receivers in an environment where the set of transmitters
comprises an unknown number of elements. In addition, we can derive
Bayesian-filter equations which describe the evolution with time of the a
posteriori probability density of the unknown user parameters, and use this
density to derive optimum detectors. In this paper we restrict ourselves to
interferer identification and data detection, while in a companion paper we
shall examine the more complex problem of estimating users' parameters.


title: Direct Dark Matter Searches

abstract:
  For many working in particle physics and cosmology successful discovery and
characterisation of the new particles that most likely explain the non-baryonic
cold dark matter, known to comprise the majority of matter in the Universe,
would be the most significant advance in physics for a century. Reviewed here
is the current status of direct searches for such particles, in particular the
so-called Weakly Interacting Massive Particles (WIMPs), together with a brief
overview of the possible future direction of the field extrapolated from recent
advances. Current best limits are at or below 10-7 pb for spin-independent
neutralino coupling, sufficient that experiments are already probing SUSY
models. However, new detectors with tonne-scale mass and/or capability to
correlate signal events to our motion through the Galaxy will likely be needed
to determine finally whether WIMPs exist.


title: Collective Modes in Two-band Superconductors

abstract:
  We analyze collective modes in two-band superconductors in the dirty limit.
It is shown that these modes exist at all temperatures $T$ below $T_{c}$
provided the frequency of the modes is higher than the inelastic scattering
rate and lower than the energy gaps $\Delta_{a,b}$. At low temperatures these
modes are related to counterphase oscillations of the condensate currents in
each band. The spectrum of the collective oscillations is similar to the
spectrum of the Josephson ''plasma'' modes in a tunnel Josephson junction but
the velocity of the mode propagation in the case under consideration is much
lower. At higher temperatures ($\Delta_{b}<T<T_{c}$) the spectrum consists of
two branches. One of them is gapless (sound-like) and the second one has a
threshhold that depends on coupling between the bands. We formulate the
conditions under which both types of collective modes can exist. The spectrum
of the collective modes can be determined by measuring the I-V characteristics
of a Josephson junction in a way as it was done by Carlson and Goldman.


title:
On critical normal sections for two-dimensional immersions in R^n and a
  Riemann-Hilbert problem

abstract:
  For orthonormal normal sections of two-dimensional immersions in R^4 we
define torsion coefficients and a functional for the total torsion. We discuss
normal sections which are critical for this functional. In particular, a global
estimate for the torsion coefficients of a critical normal section in terms of
the curvature of the normal bundle is provided.


title: Out-of-equilibrium relaxation of the Edwards-Wilkinson elastic line

abstract:
  We study the non-equilibrium relaxation of an elastic line described by the
Edwards-Wilkinson equation. Although this model is the simplest representation
of interface dynamics, we highlight that many (not though all) important
aspects of the non-equilibrium relaxation of elastic manifolds are already
present in such quadratic and clean systems. We analyze in detail the aging
behaviour of several two-times averaged and fluctuating observables taking into
account finite-size effects and the crossover to the stationary and equilibrium
regimes. We start by investigating the structure factor and extracting from its
decay a growing correlation length. We present the full two-times and size
dependence of the interface roughness and we generalize the Family-Vicsek
scaling form to non-equilibrium situations. We compute the incoherent cattering
function and we compare it to the one measured in other glassy systems. We
analyse the response functions, the violation of the fluctuation-dissipation
theorem in the aging regime, and its crossover to the equilibrium relation in
the stationary regime. Finally, we study the out-of-equilibrium fluctuations of
the previously studied two-times functions and we characterize the scaling
properties of their probability distribution functions. Our results allow us to
obtain new insights into other glassy problems such as the aging behavior in
colloidal glasses and vortex glasses.


title:
Moduli Spaces of PU(2)-Instantons on Minimal Class VII Surfaces with
  b_2=1

abstract:
  We describe explicitly the moduli spaces $M^{pst}_g(S,E)$ of polystable
holomorphic structures $E$ with $\det E\cong K$ on a rank 2 vector bundle $E$
with $c_1(E)=c_1(K)$ and $c_2(E)=0$ for all minimal class VII surfaces $S$ with
$b_2(S)=1$ and with respect to all possible Gauduchon metrics $g$. These
surfaces $S$ are non-elliptic and non-Kaehler complex surfaces and have
recently been completely classified. When $S$ is a half or parabolic Inoue
surface, $M^{pst}_g(S,E)$ is always a compact one-dimensional complex disc.
When $S$ is an Enoki surface, one obtains a complex disc with finitely many
transverse self-intersections whose number becomes arbitrarily large when $g$
varies in the space of Gauduchon metrics. $M^{pst}_g(S,E)$ can be identified
with a moduli space of PU(2)-instantons. The moduli spaces of simple bundles of
the above type leads to interesting examples of non-Hausdorff singular
one-dimensional complex spaces.


title:
The isotopic 6Li/7Li ratio in Cen X-4 and the origin of Li in X-ray
  binaries

abstract:
  Context: Cool stars, companions to compact objects, are known to show Li
abundances which are high compared to field stars of the same spectral type,
which are heavily Li depleted. This may be due either to Li production or Li
preservation in these systems. Aims: To measure the lithium isotopic ratio in
the companion star of the neutron star X-ray binary Cen X-4. Method: We use
UVES spectra obtained in years 2000 and 2004 around the orbital quadratures.
The spectra are analysed with spectrum synthesis techniques and the errors
estimated with Monte Carlo simulations. Results: We measure A(Li)=2.87+-0.20
and 6Li/7Li = 0.12+0.08-0.05 at 68% confidence level. We also present updated
system parameters with a refined determination of the orbital period and
component masses i.e. 1.14+-0.45 Msun and 0.23+-0.10 Msun for the neutron star
and companion, respectively. Conclusions: In our view the low level of 6Li
favours Li preservation scenarios, although Li production mechanisms cannot be
ruled out. In the case of preservation, no Li is freshly created in the binary,
but the tidally-locked companion has preserved its original Li by some
mechanism, possibly inhibited destruction due to its fast rotation.


title:
Behaviour of superconductivity energetic characteristics in
  electron-doped cuprates. A simple model

abstract:
  A simple model to describe the energetic phase diagram of electron-doped
cuprate superconductor is developed. Interband pairing operates between the UHB
and the defect states created by doping and supplied by both extincting HB-s.
Two defect subbands correspond to the ($\pi, 0$) and ($\pi /2,\pi /2$) momentum
regions. Extended doping quenches the bare normal state gaps (pseudogaps).
Maximal transition temperature corresponds to overlapping bands ensemble
intersected by the chemical potential. Illustrative results for $T_c$, pseudo-
and superconducting gaps are calculated on the whole doping scale. Major
characteristics features on the phase diagram are reproduced. Anticipated
manifestation of gaps doping dynamics is discussed.


title:
Mesoscopic effective material parameters for thin layers modeled as
  single and double grids of interacting loaded wires

abstract:
  As an example of thin composite layers we consider single and double grids of
periodically arranged interacting wires loaded with a certain distributed
reactive impedance. Currents induced to the wires by a normally incident plane
wave are rigorously calculated and the corresponding dipole moment densities
are determined. Using this data and the averaged fields we assign mesoscopic
material parameters for the proposed grid structures. These parameters depend
on the number of grids, and measure the averaged induced polarizations. It is
demonstrated that properly loaded double grids possess polarization response
that over some frequency range can be described by assigning negative values
for the mesoscopic parameters. Discussion is conducted on the physical
meaningfulness to assign such material parameters for thin composite slabs. The
results predicted by the proposed method for the double-grid structures are
compared with the results obtained using the commonly adopted S-parameter
retrieval procedure.


title:
Radiative and non-radiative photokinetics alteration inside a single
  metallic nanometric aperture

abstract:
  We resolve the photokinetic rates enhancement of Rhodamine 6G molecules
diffusing in a water-glycerol mixture within a single nanometric aperture
milled in an opaque aluminium film. Combining fluorescence correlation
spectroscopy and lifetime measurements, we report the relative influence of
excitation, radiative and non-radiative decay in the fluorescence process,
giving a detailed description of the physics behind the overall 15 fold
enhancement of the average fluorescence rate per molecule. This procedure is
broadly adaptable to a wide range of nanostructures.


title:
Partial decoupling between strain and polarization in mono-oriented
  Pb(Zr0.2Ti0.8)O3 thin film

abstract:
  The structural evolution of epitaxial mono-oriented (i.e. with the c-axis
perpendicular to the interface) ferroelectric Pb(Zr0.2,Ti0.8)O3 thin film has
been investigated, using high resolution, temperature dependent, X-ray
diffraction. The full set of lattice parameters was obtained, it allowed to
estimate the variation of the polarization as a function of temperature,
underlying the difference between the polarization-induced tetragonality and
the elastic one. The temperature evolution of the misfit strain has been
calculated and found to be in good agreement with the theoretical
temperature-misfit strain phase diagram


title:
XANES determination of chromium oxidation states in glasses: comparison
  with optical absorption spectroscopy

abstract:
  The oxidation state of chromium in glasses melted in an air atmosphere with
and without refining agents was investigated by Cr K-edge X-ray Absorption
Near-Edge Structure (XANES) and optical absorption spectroscopy. A good
agreement in the relative proportion of Cr(III) and Cr(VI) is obtained between
both methods. We show that the chemical dependence of the absorption
coefficient of Cr(III) is less important in XANES than in optical absorption
spectroscopy. The comparison of glasses melted under different conditions
provides an indirect assessment of the molar extinction coefficient of Cr(VI)
in glasses.


title: The Skolem-Bang Theorems in Ordered Fields with an $IP$

abstract:
  This paper is concerned with the extent to which the Skolem-Bang theorems in
Diophantine approximations generalise from the standard setting of $<R,Z>$ to
structures of the form $<F,I>$, where $F$ is an ordered field and $I$ is an
integer part of $F$. We show that some of these theorems are hold
unconditionally in general case (ordered fields with an integer part). The
remainder results are based on Dirichlet's and Kronecker's theorems. Finally we
extend Dirichlet's theorem to ordered fields with $IE_1$ integer part.


title:
A nonlinearly ill-posed problem of reconstructing the temperature from
  interior data

abstract:
  We consider the problem of reconstructing, from the interior data $u(x,1)$, a
function $u$ satisfying a nonlinear elliptic equation $$ \Delta u =
f(x,y,u(x,y)), x \in \RR, y > 0. $$


title:
Integral representation of solutions to Fuchsian system and Heun's
  equation

abstract:
  We obtain integral representations of solutions to special cases of the
Fuchsian system of differential equations and Heun's differential equation. In
particular, we calculate the monodromy of solutions to the Fuchsian equation
that corresponds to Picard's solution of the sixth Painlev\'e equation, and to
Heun's equation.


title:
Clustered Star Formation in the Small Magellanic Cloud. A Spitzer/IRAC
  View of the Star-Forming Region NGC 602/N 90

abstract:
  We present Spitzer/IRAC photometry on the star-forming HII region N 90,
related to the young stellar association NGC 602 in the Small Magellanic Cloud.
Our photometry revealed bright mid-infrared sources, which we classify with the
use of a scheme based on templates and models of red sources in the Milky Way,
and criteria recently developed from the Spitzer Survey of the SMC for the
selection of candidate Young Stellar Objects (YSOs). We detected 57 sources in
all four IRAC channels in a 6.2' x 4.8' field-of-view centered on N 90; 22 of
these sources are classified as candidate YSOs. We compare the locations of
these objects with the position of optical sources recently found in the same
region with high-resolution HST/ACS imaging of NGC 602, and we find that 17
candidate YSOs have one or more optical counterparts. All of these optical
sources are identified as pre-main sequence stars, indicating, thus, ongoing
clustered star formation events in the region. The positions of the detected
YSOs and their related PMS clusters give a clear picture of the current star
formation in N 90, according to which the young stellar association
photo-ionizes the surrounding interstellar medium, revealing the HII nebula,
and triggering sequential star formation events mainly along the eastern and
southern rims of the formed cavity of the parental molecular cloud.


title: The Road to Quantum Artificial Intelligence

abstract:
  This paper overviews the basic principles and recent advances in the emerging
field of Quantum Computation (QC), highlighting its potential application to
Artificial Intelligence (AI). The paper provides a very brief introduction to
basic QC issues like quantum registers, quantum gates and quantum algorithms
and then it presents references, ideas and research guidelines on how QC can be
used to deal with some basic AI problems, such as search and pattern matching,
as soon as quantum computers become widely available.


title:
Imbalanced Superfluid Phase of a Trapped Fermi Gas in the BCS-BEC
  Crossover Regime

abstract:
  We theoretically investigate the ground state of trapped neutral fermions
with population imbalance in the BCS-BEC crossover regime. On the basis of the
single-channel Hamiltonian, we perform full numerical calculations of the
Bogoliubov-de Gennes equation coupled with the regularized gap and number
equations. The zero-temperature phase diagram in the crossover regime is
presented, where the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) pairing state
governs the weak-coupling BCS region of a resonance. It is found that the FFLO
oscillation vanishes in the BEC side, in which the system under population
imbalance turns into a phase separation (PS) between locally binding superfluid
and fully polarized spin domains. We also demonstrate numerical calculations
with a large particle number O(10^5), comparable to that observed in recent
experiments. The resulting density profile on a resonance yields the PS, which
is in good agreement with the recent experiments, while the FFLO modulation
exists in the pairing field. It is also proposed that the most favorable
location for the detection of the FFLO oscillation is in the vicinity of the
critical population imbalance in the weak coupling BCS regime, where the
oscillation periodicity becomes much larger than the interparticle spacing.
Finally, we analyze the radio-frequency (RF) spectroscopy in the imbalanced
system. The clear difference in the RF spectroscopy between BCS and BEC sides
reveals the structure of the pairing field and local ``magnetization''.


title:
Convergence to Equilibrium for the Cahn-Hilliard Equation with Wentzell
  Boundary Condition

abstract:
  In this paper we consider the Cahn-Hilliard equation endowed with Wentzell
boundary condition which is a model of phase separation in a binary mixture
contained in a bounded domain with permeable wall. Under the assumption that
the nonlinearity is analytic with respect to unknown dependent function, we
prove the convergence of a global solution to an equilibrium as time goes to
infinity by means of a suitable \L ojasiewicz-Simon type inequality with
boundary term. Estimates of convergence rate are also provided.


title: The Holographic Interpretation of Hawking Radiation

abstract:
  Holography gives us a tool to view the Hawking effect from a new, classical
perspective. In the context of Randall-Sundrum braneworld models, we show that
the basic features of four-dimensional evaporating solutions are nicely
translated into classical five-dimensional language. This includes the dual
bulk description of particles tunneling through the horizon.


title: Mexican Hat Wavelet on the Heisenberg Group

abstract:
  In this article wavelets (admissible vectors) on the Heisenberg group are
studied from the point of view of Calderon's formula. Further we shall show
that for the class of Schwartz functions the Calderon admissibility condition
is equivalent to the usual admissibility property which will be introduced in
this work. Furthermore motivated by a well-known example on the real line, the
Mexican-Hat wavelet, we demonstrate the existence and construction of an
analogous wavelet on the Heisenberg Lie group with 2 vanishing moments, which
together with all of its derivatives has Gaussian decay.


title:
On Some Properties of Linear Mapping Induced by Linear Descriptor
  Differential Equation

abstract:
  In this paper we introduce linear mapping D from WnF\subset Ln into Lm\times
Rm, induced by linear differential equation d/dt
Fx(t)-C(t)x(t)=f(t),Fx(t_0)=f_0. We prove that D is closed dense defined
mapping for any m\times n-matrix F. Also adjoint mapping D* is constructed and
its domain WmF is described. Some kind of so-called "integration by parts"
formula for vectors from WnF, WmF is suggested. We obtain a necessary and
sufficient condition for existence of generalized solution of equation
Dx=(f,f_0). Also we find a sufficient criterion for closureness of the R(D) in
Lm\times Rm which is formulated in terms of transparent conditions for blocks
of matrix C(t). Some examples are supplied to illustrate obtained results.


title: Notes on planar semimodular lattices. I. Construction

abstract:
  We construct all planar semimodular lattices in three simple steps from the
direct product of two chains.


title:
Just how different are SU(2) and SU(3) Landau-gauge propagators in the
  IR regime?

abstract:
  The infrared behavior of gluon and ghost propagators in Yang-Mills theories
is of central importance for understanding quark and gluon confinement in QCD.
While simulations of pure SU(3) gauge theory correspond to the physical case in
the limit of infinite quark mass, the SU(2) case (i.e. pure two-color QCD) is
usually employed as a simplification, in the hope that qualitative features be
the same as for the SU(3) case. Here we carry out the first comparative study
of lattice (Landau) propagators for these two gauge groups. Our data were
especially produced with equivalent lattice parameters in order to allow a
careful comparison of the two cases. We find very good agreement between SU(2)
ans SU(3) propagators, showing that in the IR limit the equivalence of the two
cases is quantitative, at least down to about 1 GeV. Our results suggest that
the infrared behavior of these propagators is independent of the gauge group
SU(N_c), as predicted by Schwinger-Dyson equations.


title:
A classification of Lie algebras of pseudounitary groups in the
  techniques of Clifford algebras

abstract:
  In this paper we present new formulas, which represent commutators and
anticommutators of Clifford algebra elements as sums of elements of different
ranks. Using these formulas we consider subalgebras of Lie algebras of
pseudounitary groups. Our main techniques are Clifford algebras. We have find
12 types of subalgebras of Lie algebras of pseudounitary groups.


title: Closed non-abelian strings

abstract:
  With the aim of finding a framework for describing $(2,0)$ theory, we propose
a non-abelian gerbe with surface holonomies that can parallel transport closed
strings only.


title:
Adaptive classification of temporal signals in fixed-weights recurrent
  neural networks: an existence proof

abstract:
  We address the important theoretical question why a recurrent neural network
with fixed weights can adaptively classify time-varied signals in the presence
of additive noise and parametric perturbations. We provide a mathematical proof
assuming that unknown parameters are allowed to enter the signal nonlinearly
and the noise amplitude is sufficiently small.


title: Multi-strange baryon correlations at RHIC

abstract:
  Multi-strange baryon azimuthal correlations were observed in d+Au and Au+Au
data taken by the STAR detector at RHIC. We extract the same-side per-trigger
yields for a variety of strange particle species and trigger pt, but do not
observe any species dependence. We also report the observation of an elongation
in the Delta-eta; direction of the Xi correlation peak, the ridge. Comparing
the same-side yields in d+Au and Au+Au data, we conclude that the same-side
yield of the azimuthal-only Xi correlations is greatly enhanced by the ridge
yield. We also report the first observation of a strong same-side peak in the
Omega baryon triggered azimuthal correlations.


title: Rings of integers of type $K(\pi,1)$

abstract:
  We investigate the Galois group $G_S(p)$ of the maximal $p$-extension
unramified outside a finite $S$ of primes of a number field in the (tame) case,
when no prime dividing $p$ is in $S$. We show that the cohomology of $G_S(p)$
is 'often' isomorphic to the etale cohomology of the scheme $\Spec(\O_k \sm
S)$, in particular, $G_S(p)$ is of cohomological dimension~2 then.


title: Laplacian Spectrum and Protein-Protein Interaction Networks

abstract:
  From the spectral plot of the (normalized) graph Laplacian, the essential
qualitative properties of a network can be simultaneously deduced. Given a
class of empirical networks, reconstruction schemes for elucidating the
evolutionary dynamics leading to those particular data can then be developed.
This method is exemplified for protein-protein interaction networks. Traces of
their evolutionary history of duplication and divergence processes are
identified. In particular, we can identify typical specific features that
robustly distinguish protein-protein interaction networks from other classes of
networks, in spite of possible statistical fluctuations of the underlying data.


title: Single-Molecule Junction Conductance through Diaminoacenes

abstract:
  The study of electron transport through single molecules is essential to the
development of molecular electronics. Indeed, trends in electronic conductance
through organic nanowires have emerged with the increasing reliability of
electron transport measurements at the single-molecule level. Experimental and
theoretical work has shown that tunneling distance, HOMO-LUMO gap and molecular
conformation influence electron transport in both saturated and pi-conjugated
nanowires. However, there is relatively little experimental data on electron
transport through fused aromatic rings. Here we show using diaminoacenes that
conductivity depends not only on the number of fused aromatic rings in the
molecule, which defines the molecular HOMO-LUMO gap, but also on the position
of the amino groups on the rings. Specifically, we find that conductance is
highest with minimal disruption of aromaticity in fused aromatic nanowires.


title: Unsuccessful cosmology with Modified Gravity Models

abstract:
  A class of Modified Gravity Models, consisting of inverse powers of linear
combination of quadratic curvature invariants, is studied in the full parameter
space. We find that singularity-free cosmological solutions, interpolating
between an almost-Friedmann universe at Big Bang Nucleosynthesis and an
accelerating universe today, exist only in a restricted parameter space.
Furthermore, for all parameters of the models, there is an unstable scalar mode
of the gravitational field. Therefore we conclude that this class of Modified
Gravity Models is not viable.


title:
Gaussian number-squeezed states for sub-shot-noise interferometery in
  double-well Bose-Einstein condensates

abstract:
  This paper has been withdrawn. It is based on numerical results limited by
computing resources to N=3000 atoms. Using a newly understood geometric method
we find that the observed scaling with N saturates at around N=7000 or even
higher. In light of this new finding we withdraw the paper and will submit a
revised manuscript reflecting our new understanding.


title: The Calibration of Mid-Infrared Star Formation Rate Indicators

abstract:
  With the goal of investigating the degree to which the mid-infrared emission
traces the star formation rate (SFR), we analyze Spitzer 8 um and 24 um data of
star-forming regions in a sample of 33 nearby galaxies with available
HST/NICMOS images in the Paschen-alpha (1.8756 um) emission line. The galaxies
are drawn from the Spitzer Infrared Nearby Galaxies Survey (SINGS) sample, and
cover a range of morphologies and a factor ~10 in oxygen abundance. Published
data on local low-metallicity starburst galaxies and Luminous Infrared Galaxies
are also included in the analysis. Both the stellar-continuum-subtracted 8 um
emission and the 24 um emission correlate with the extinction-corrected
Pa-alpha line emission, although neither relationship is linear. Simple models
of stellar populations and dust extinction and emission are able to reproduce
the observed non-linear trend of the 24 um emission versus number of ionizing
photons, including the modest deficiency of 24 um emission in the low
metallicity regions, which results from a combination of decreasing dust
opacity and dust temperature at low luminosities. Conversely, the trend of the
8 um emission as a function of the number of ionizing photons is not well
reproduced by the same models. The 8 um emission is contributed, in larger
measure than the 24 um emission, by dust heated by non-ionizing stellar
populations, in agreement with previous findings. Two SFR calibrations, one
using the 24 um emission and the other using a combination of the 24 um and
H-alpha luminosities (Kennicutt et al. 2007), are presented. No calibration is
presented for the 8 um emission, because of its significant dependence on both
metallicity and environment. The calibrations presented here should be directly
applicable to systems dominated by on-going star formation.


title: Bell's Theorem refuted with a Kolmogorovian counterexample

abstract:
  The statistics behind Bell's inequality is demonstrated to allow a
Kolmogorovian (i.e. classical) model of probabilities that recovers the quantum
covariance.


title:
Ray-tracing and physical-optics analysis of the aperture efficiency in a
  radio telescope

abstract:
  The performance of telescope systems working at microwave or visible/IR
wavelengths is typically described in terms of different parameters according
to the wavelength range. Most commercial ray tracing packages have been
specifically designed for use with visible/IR systems and thus, though very
flexible and sophisticated, do not provide the appropriate parameters to fully
describe microwave antennas, and thus to compare with specifications. In this
work we demonstrate that the Strehl ratio is equal to the phase efficiency when
the apodization factor is taken into account. The phase efficiency is the most
critical contribution to the aperture efficiency of an antenna, and the most
difficult parameter to optimize during the telescope design. The equivalence
between the Strehl ratio and the phase efficiency gives the designer/user of
the telescope the opportunity to use the faster commercial ray-tracing software
to optimize the design. We also discuss the results of several tests performed
to check the validity of this relationship that we carried out using a
ray-tracing software, ZEMAX and a full Physical Optics software, GRASP9.3,
applied to three different telescope designs that span a factor of $\simeq 10
in terms of D/lambda. The maximum measured discrepancy between phase efficiency
and Strehl ratio varies between $\simeq 0.4 and 1.9 up to an offset angle of
>40 beams, depending on the optical configuration, but it is always less than
0.5 where the Strehl ratio is >0.95.


title: Lorentzian and signature changing branes

abstract:
  General hypersurface layers are considered in order to describe brane-worlds
and shell cosmologies. No restriction is placed on the causal character of the
hypersurface which may thus have internal changes of signature. Strengthening
the results in our previous letter [1], we confirm that a good, regular and
consistent description of signature change is achieved in these brane/shells
scenarios, while keeping the hypersurface and the bulk completely regular. Our
formalism allows for a unified description of the traditional timelike
branes/shells together with the signature-changing, or pure null, ones. This
allows for a detailed comparison of the results in both situations. An
application to the case of hypersurface layers in static bulks is presented,
leading to the general Robertson-Walker geometry on the layer --with a possible
signature change. Explicit examples on anti de Sitter bulks are then studied.
The permitted behaviours in different settings ($Z_{2}$-mirror branes,
asymmetric shells, signature-changing branes) are analysed in detail. We show
in particular that (i) in asymmetric shells there is an upper bound for the
energy density, and (ii) that the energy density within the brane vanishes when
approaching a change of signature. The description of a signature change as a
`singularity' seen from within the brane is considered. We also find new
relations between the fundamental constants in the brane/shell, its tension,
and the cosmological and gravitational constants of the bulk, independently of
the existence or not of a change of signature.


title:
Absolute and convective instabilities in an inviscid compressible mixing
  layer

abstract:
  We consider the stability of a compressible shear flow separating two streams
of different speeds and temperatures. The velocity and temperature profiles in
this mixing layer are hyperbolic tangents.
  The normal mode analysis of the flow stability reduces to an eigenvalue
problem for the pressure perturbation. We briefly describe the numerical method
that we used to solve this problem. Then, we introduce the notions of the
absolute and convective instabilities and examine the effects of Mach number,
and the velocity and temperature ratios of each stream on the transition
between convective and absolute instabilities. Finally, we discuss the
implication of the results presented in this paper for the heliopause
stability.


title: On the cohomology of vector fields on parallelizable manifolds

abstract:
  In the present paper we determine for each parallelizable smooth compact
manifold $M$ the cohomology spaces $H^2(V_M,\bar\Omega^p_M)$ of the Lie algebra
$V_M$ of smooth vector fields on $M$ with values in the module $\bar\Omega^p_M
= \Omega^p_M/d\Omega^{p-1}_M$. The case of $p=1$ is of particular interest
since the gauge algebra $C^\infty (M,k)$ has the universal central extension
with center $\bar\Omega^1_M$, generalizing affine Kac-Moody algebras. The
second cohomology $H^2(V_M, \bar\Omega^1_M)$ classifies twists of the
semidirect product of $V_M$ with the universal central extension $C^\infty
(M,k) \oplus \bar\Omega^1_M$.


title: Linear response formula for piecewise expanding unimodal maps

abstract:
  The average R(t) of a smooth function with respect to the SRB measure of a
smooth one-parameter family f_t of piecewise expanding interval maps is not
always Lipschitz. We prove that if f_t is tangent to the topological class of
f_0, then R(t) is differentiable at zero, and the derivative coincides with the
resummation previously proposed by the first named author of the (a priori
divergent) series given by Ruelle's conjecture.


title:
Enhanced generation of VUV radiation by four-wave mixing in mercury
  using pulsed laser vaporization

abstract:
  The efficiency of a coherent VUV source at 125 nm, based on 2-photon resonant
four-wave mixing in mercury vapor, has been enhanced by up to 2 orders of
magnitude. This enhancement was obtained by locally heating a liquid Hg surface
with a pulsed excimer laser, resulting in a high density vapor plume in which
the nonlinear interaction occurred. Energies up to 5 μJ (1 kW peak power)
have been achieved while keeping the overall Hg cell at room temperature,
avoiding the use of a complex heat pipe. We have observed a strong saturation
of the VUV yield when peak power densities of the fundamental beams exceed the
GW/cm2 range, as well as a large intensity-dependant broadening (up to ~30
cm-1) of the two-photon resonance. The source has potential applications for
high resolution interference lithography and photochemistry.


title:
Model-independent extraction of two-photon effects in elastic
  electron-proton scattering

abstract:
  We address the discrepancy between the Rosenbluth and polarization transfer
data for the electromagnetic form factors of the nucleon. Assuming that the
effect of two-photon corrections on the polarization transfer data is
negligible, we obtain a model-independent estimate of the two-photon correction
Delta^(2\gamma). We analyze the polarization transfer data and the cross
section data separately using dispersion relations. A central value as well as
an error estimate for Delta^(2\gamma) is then obtained from a comparison of the
two analyses. The resulting values for Delta^(2\gamma) are in good agreement
with direct calculations available in the literature.


title: Isometries of CAT(0) cube complexes are semi-simple

abstract:
  We show that an automorphism of an arbitrary CAT(0) cube complex either has a
fixed point or preserves some combinatorial axis. It follows that when a group
contains a distorted cyclic subgroup, it admits no proper action on a discrete
space with walls.


title:
Clusters under strong VUV pulses: A quantum-classical hybrid-description
  incorporating plasma effects

abstract:
  The quantum-classical hybrid-description of rare-gas clusters interacting
with intense light pulses which we have developed is described in detail. Much
emphasis is put on the treatment of screening electrons in the cluster which
set the time scale for the evolution of the system and form the link between
electrons strongly bound to ions and quasi-free plasma electrons in the
cluster. As an example we discuss the dynamics of an Ar147 cluster exposed to a
short VUV laser pulse of 20eV photon energy.


title:
Holographic Confinement/Deconfinement Phase Transitions of AdS/QCD in
  Curved Spaces

abstract:
  Recently Herzog has shown that deconfinement of AdS/QCD can be realized, in
the hard-wall model where the small radius region is removed in the
asymptotically AdS space, via a first order Hawking-Page phase transition
between a low temperature phase given by a pure AdS geometry and a high
temperature phase given by the AdS black hole in Poincare coordinates. In this
paper we first extend Herzog's work to the hard wall AdS/QCD model in curved
spaces by studying the thermodynamics of AdS black holes with spherical or
negative constant curvature horizon, dual to a non-supersymmetric Yang-Mills
theory on a sphere or hyperboloid respectively. For the spherical horizon case,
we find that the temperature of the phase transition increases by introducing
an infrared cutoff, compared to the case without the cutoff; For the hyperbolic
horizon case, there is a gap for the infrared cutoff, below which the
Hawking-Page phase transition does not occur. We also discuss charged AdS black
holes in the grand canonical ensemble, corresponding to a Yang-Mills theory at
finite chemical potential, and find that there is always a gap for the infrared
cutoff due to the existence of a minimal horizon for the charged AdS black
holes with any horizon topology.


title: Attosecond resolved charging of clusters

abstract:
  Attosecond laser pulses open the door to resolve microscopic electron
dynamics in time. Experiments performed include the decay of a core hole, the
time-resolved measurement of photo ionization and electron tunneling. The
processes investigated share the coherent character of the dynamics involving
very few, ideally one active electron. Here, we introduce a scheme to probe
dissipative multi-electron motion in time. In this context attosecond probing
enables one to obtain information which is lost at later times and cannot be
retrieved by conventional methods in the energy domain due to the incoherent
nature of the dynamics. As a specific example we will discuss the charging of a
rare-gas cluster during a strong femtosecond pulse with attosecond pulses. The
example illustrates the proposed use of attosecond pulses and suggests an
experimental resolution of a controversy about the mechanism of energy
absorption by rare-gas clusters in strong vacuum-ultraviolet (VUV) pulses.


title:
Product preserving bundle functors on multifibered and multifoliate
  manifolds

abstract:
  We show that the set of the equivalence classes of multifoliate structures is
in one-to-one correspondence with the set of equivalence classes of finite
complete projective systems of vector space epimorphisms. After that we give
the complete description of all product preserving bundle functors on the
categories of multifibered and multifoliate manifolds.


title:
Commutator Relations Reveal Solvable Structures in Unambiguous State
  Discrimination

abstract:
  We present a criterion, based on three commutator relations, that allows to
decide whether two self-adjoint matrices with non-overlapping support are
simultaneously unitarily similar to quasidiagonal matrices, i.e., whether they
can be simultaneously brought into a diagonal structure with 2x2-dimensional
blocks. Application of this criterion to unambiguous state discrimination
provides a systematic test whether the given problem is reducible to a solvable
structure. As an example, we discuss unambiguous state comparison.


title: Higgs-pair Production in Littlest Higgs Model with T-parity

abstract:
  The Higgs-pair production process at the CERN Large Hadron Collider (LHC),
which will provide a way to test the Higgs boson self-coupling, may be
sensitive to new physics. In the framework of the littlest Higgs model with
T-parity, such Higgs-pair production can proceed through additional loop
diagrams and thus the production rate can be quite different from the Standard
Model (SM) prediction. Our calculations show that, due to the loop
contributions of both T-even and T-odd quarks predicted in this model, the
production rate can be significantly enhanced relative to the SM prediction and
also can be larger than the production rate in the minimal supersymmetric
model. Also, we find that the T-odd quark contributions, which were ignored in
a previous study, are equally important compared with the T-even quark
contributions.


title: Vacuumless kinks systems from vacuum ones, an example

abstract:
  Some years ago, Cho and Vilenkin, introduced a model which presents
topological solutions, despite not having degenerate vacua as is usually
expected. Here we present a new model with topological defects, connecting
degenerate vacua but which in a certain limit recovers precisely the one
proposed originally by Cho and Vilenkin. In other words, we found a kind of
parent model for the so called vacuumless model. Then the idea is extended to a
model recently introduced by Bazeia et al. Finally, we trace some comments the
case of the Liouville model.


title:
Low Star Formation Rates for z=1 Early-Type Galaxies in the Very Deep
  GOODS-MIPS Imaging: Implications for their Optical/Near-Infrared Spectral
  Energy Distributions

abstract:
  We measure the obscured star formation in z~1 early-type galaxies. This
constrains the influence of star formation on their optical/near-IR colors,
which, we found, are redder than predicted by the model by Bruzual & Charlot
(2003). From deep ACS imaging we construct a sample of 95 morphologically
selected early-type galaxies in the HDF-N and CDF-S with spectroscopic
redshifts in the range 0.85<z<1.15. We measure their 24 micron fluxes from the
deep GOODS-MIPS imaging and derive the IR luminosities and star formation
rates. The fraction of galaxies with >2 sigma detections (~25 muJy} is
17(-4,+9)%. Of the 15 galaxies with significant detections at least six have an
AGN. Stacking the MIPS images of the galaxies without significant detections
and adding the detected galaxies without AGN we find an upper limit on the mean
star formation rate (SFR) of 5.2+/-3.0 Msol yr^-1, and on the mean specific SFR
of 4.6+/-2.2 * 10^-11 yr^-1. Under the assumption that the average SFR will
decline at the same rate as the cosmic average, the in situ growth in stellar
mass of the early-type galaxy population is less than 14+/-7% between z=1 and
the present. We show that the typically low IR luminosity and SFR imply that
the effect of obscured star formation (or AGN) on their rest-frame
optical/near-IR SEDs is negligible for ~90% of the galaxies in our sample.
Hence, their optical/near-IR colors are most likely dominated by evolved
stellar populations. This implies that the colors predicted by the Bruzual &
Charlot (2003) model for stellar populations with ages similar to those of z~1
early-type galaxies (~1-3 Gyr) are most likely too blue, and that stellar
masses of evolved, high-redshift galaxies can be overestimated by up to a
factor of ~2.


title: Velocity-Dependent Models for Non-Abelian/Entangled String Networks

abstract:
  We develop velocity-dependent models describing the evolution of string
networks that involve several types of interacting strings, each with a
different tension. These incorporate the formation of Y-type junctions with
links stretching between colliding strings, while always ensuring energy
conservation. These models can be used to describe network evolution for
non-abelian strings as well as cosmic superstrings. The application to $Z_{N}$
strings in which interactions are topologically constrained, demonstrates that
a scaling regime is generally reached which involves a hierarchy of string
densities with the lightest most abundant. We also study hybrid networks of
cosmic superstrings, where energetic considerations are more important in
determining interaction outcomes. We again find that networks tend towards
scaling, with the three lightest network components being dominant and having
comparable number densities, while the heavier string states are suppressed. A
more quantitative analysis depends on the precise calculation of the string
interaction matrix using the underlying string or field theory. Nevertheless,
these results provide further evidence that the presence of junctions in a
string network does not obstruct scaling.


title:
A new algorithm for modelling photoionising radiation in smoothed
  particle hydrodynamics

abstract:
  We present a new fast algorithm which allows the simulation of ionising
radiation emitted from point sources to be included in high-resolution
three-dimensional smoothed particle hydrodynamics simulations of star cluster
formation. We employ a Str\"omgren volume technique in which we use the
densities of particles near the line-of-sight between the source and a given
target particle to locate the ionisation front in the direction of the target.
Along with one--dimensional tests, we present fully three--dimensional
comparisons of our code with the three--dimensional Monte-Carlo radiative
transfer code, MOCASSIN, and show that we achieve good agreement, even in the
case of highly complex density fields.


title: Beyond the PI Controllers in First-Order Time-Delay Systems

abstract:
  In this paper the following three control systems for first-order time-delay
plants are studied and compared: the feedback proportional-integral controller
(PI), the Smith Predictor (SP) and a proposed variable structure consisting of
two blocks. This structure acts as an open-loop proportional controller, after
a setpoint change, and as a closed-loop integrating controller, when the error
enters in a preset band. A chart, provided with the borderlines of the
stability zone and with the curves of two design parameters, is implemented for
each controller. The first parameter is the overshoot of the controlled
variable, evaluated during a step change of the setpoint and made equal to a
preset value. The second parameter, only for the PI and SP controllers, is the
integral of the squared error (ISE), which must have the minimum allowable
value. The ISE is also assumed as comparison index and the proposed controller
appears as the best.


title:
Efficient control of transient wave forms to prevent spreading
  depolarizations

abstract:
  In various neurological disorders spatio-temporal excitation patterns
constitute examples of excitable behavior emerging from pathological pathways.
During migraine, seizure, and stroke an initially localized pathological state
can temporarily spread indicating a transition from non-excitable to excitable
behavior. We investigate these transient wave forms in the generic
FitzHugh-Nagumo (FHN) system of excitable media. Our goal is to define an
efficient control minimizing the volume of invaded tissue. The general point of
such a therapeutic optimization is how to apply control theory in the framework
of structures in differential geometry by regarding parameter plane M of the
FHN system as a differential manifold endowed with a metric. We suggest to
equip M with a metric given by pharmacokinetic-pharmacodynamic models of drug
receptor interaction.


title: The variety of exterior powers of linear maps

abstract:
  Let $K$ be a field and $V$ and $W$ be $K$-vector spaces of dimension $m$ and
$n$. Let $\phi$ be the canonical map from $Hom(V,W)$ to $Hom(\wedge^t
V,\wedge^t W)$. We investigate the Zariski closure $X_t$ of the image $Y_t$ of
$\phi$. In the case $t=\min(m,n)$, $Y_t=X_t$ is the cone over a Grassmannian,
but $X_t$ is larger than $Y_t$ for $1<t<\min(m,n)$. We analyze the
$G=\GL(V)\times\GL(W)$-orbits in $X_t$ via the corresponding $G$-stable prime
ideals. It turns out that they are classified by two numerical invariants, one
of which is the rank and the other a related invariant that we call small rank.
Surprisingly, the orbits in $X_t\setminus Y_t$ arise from the images $Y_u$ for
$u<t$ and simple algebraic operations. In the last section we determine the
singular locus of $X_t$. Apart from well-understood exceptional cases, it is
formed by the elements of rank $\le 1$ in $Y_t$.


title: The method for solving the KdV-equation

abstract: The method for solving the KdV are considered.


title: A model for the Globular Cluster extreme anomalies

abstract:
  In spite of the efforts made in the latest years, still there is no
comprehensive explanation for the chemical anomalies of globular cluster stars.
Among these, the most striking is oxygen depletion, which reaches values down
to [O/Fe]~-0.4 in most clusters, but in M13 it goes down to less than [O/Fe]~ -
1. In this work we suggest that the anomalies are due to the super position of
two different events: 1) PRIMORDIAL SELF-ENRICHMENT: this is asked to explain
the oxygen depletion down to a minimum value [O/Fe]~ -0.4; 2) EXTRA MIXING IN A
FRACTION OF THE STARS ALREADY BORN WITH ANOMALOUS COMPOSITION: these objects,
starting with already low [O/Fe], will reduce the oxygen abundance down to the
most extreme values. Contrary to other models that invoke extra mixing to
explain the chemical anomalies, we suggest that it is active only if there is a
fraction of the stars in which the primordial composition is not only oxygen
depleted, but also extremely helium rich (Y~ 0.4), as found in a few GCs from
their main sequence multiplicity. We propose that the rotational evolution (and
an associated extra mixing) of extremely helium rich stars may be affected by
the fact that they develop a very small or non existent molecular weight
barrier during the evolution. We show that extra mixing in these stars, having
initial chemistry that has already been CNO processed, affects mainly the
oxygen abundance, and to a much smaller extent if affects the sodium abundance.
The model also predicts a large fluorine depletion concomitant with the oxygen
depletion, and a further enhancement of the surface helium abundance, which
reaches values close to Y=0.5 in the computed models. We stress that, in this
tentative explanation, those stars that are primordially O--depleted, but ARE
NOT extremely helium rich do not suffer deep extra mixing.


title:
A ferrofluid based neural network: design of an analogue associative
  memory

abstract:
  We analyse an associative memory based on a ferrofluid, consisting of a
system of magnetic nano-particles suspended in a carrier fluid of variable
viscosity subject to patterns of magnetic fields from an array of input and
output magnetic pads. The association relies on forming patterns in the
ferrofluid during a trainingdphase, in which the magnetic dipoles are free to
move and rotate to minimize the total energy of the system. Once equilibrated
in energy for a given input-output magnetic field pattern-pair the particles
are fully or partially immobilized by cooling the carrier liquid. Thus produced
particle distributions control the memory states, which are read out
magnetically using spin-valve sensors incorporated in the output pads. The
actual memory consists of spin distributions that is dynamic in nature,
realized only in response to the input patterns that the system has been
trained for. Two training algorithms for storing multiple patterns are
investigated. Using Monte Carlo simulations of the physical system we
demonstrate that the device is capable of storing and recalling two sets of
images, each with an accuracy approaching 100%.


title: Dust Distribution during Reionization

abstract:
  The dust produced by the first generation of stars will be a foreground to
cosmic microwave background. In order to evaluate the effect of this early
dust, we calculate the power spectrum of the dust emission anisotropies and
compare it with the sensitivity limit of the Planck satellite. The spatial
distribution of the dust is estimated through the distribution of dark matter.
At small angular scales ($\ell \gtrsim 1000$) the dust signal is found to be
noticeable with the Planck detector for certain values of dust lifetime and
production rates. The dust signal is also compared to sensitivities of other
instruments. The early dust emission anisotropies are finally compared to those
of local dust and they are found to be similar in magnitude at mm wavelengths.


title: Plasmarings as dual black rings

abstract:
  We construct solutions to the relativistic Navier-Stokes equations that
describe the long wavelength collective dynamics of the deconfined plasma phase
of N=4 Yang Mills theory compactified down to d=3 on a Scherk-Schwarz circle
and higher dimensional generalisations. Our solutions are stationary, axially
symmetric spinning balls and rings of plasma. These solutions, which are dual
to (yet to be constructed) rotating black holes and black rings in
Scherk-Schwarz compactified AdS(5) and AdS(6), and have properties that are
qualitatively similar to those of black holes and black rings in flat five
dimensional supergravity.


title:
Point-contact spectroscopy of the antiferromagnetic superconductor
  HoNi2B2C in the normal and superconducting state

abstract:
  Point-contact (PC) spectroscopy measurements on antiferromagnetic (AF)
(T_N=5.2K) HoNi2B2C single crystals in the normal and two different
superconducting (SC) states (T_c=8.5K and $T_c^*=5.6K) are reported. The PC
study of the electron-boson(phonon) interaction (EB(P)I) spectral function
reveals pronounced phonon maxima at 16, 22 and 34meV. For the first time the
high energy maxima at about 50meV and 100meV are resolved. Additionally, an
admixture of a crystalline-electric-field (CEF) excitations with a maximum near
10meV and a `magnetic` peak near 3meV are observed. The contribution of the
10-meV peak in PC EPI constant \lambda_PC is evaluated as 20-30%, while
contribution of the high energy modes at 50 and 100meV amounts about 10% for
each maxima, so the superconductivity might be affected by CEF excitations. The
SC gap in HoNi2B2C exhibits a standard single-band BCS-like dependence, but
vanishes at $T_c^*=5.6K<T_c, with 2\Delta/kT_c^*=3.9. The strong coupling
Eliashberg analysis of the low-temperature SC phase with T_c^*=5.6K =T_N,
coexisting with the commensurate AF structure, suggests a sizable value of the
EPI constant \lambda_s=0.93. We also provide strong support for the recently
proposed by us ''Fermi surface (FS) separation'' scenario for the coexistence
of magnetism and superconductivity in magnetic borocarbides, namely, that the
superconductivity in the commensurate AF phase survives at a special (nearly
isotropic) FS sheet without an admixture of Ho 5d states. Above T_c^* the SC
features in the PC characteristics are strongly suppressed pointing to a
specific weakened SC state between T_c* and T_c.


title: X-ray Evolution of SN 1987A

abstract:
  The X-ray observations of SN 1987A over the previous 20 years have seen the
emergence of soft X-rays from the interaction of the explosion shock wave with
the ambient medium. This shock wave is now interacting strongly with the inner
ring and might have passed already the highest density regions. The emission
can be described by thermal models with two temperatures, with perhaps some but
little change over time. Relative to the elemental abundances prevailing in the
LMC the inner ring shows an overabundance of Si and S compared to the lighter
elements and Fe, which suggests that the ring consists of highly processed
matter dredged up in a binary merger event well before the explosion. The X-ray
lightcurves between 0.5--2 keV and 3--10 keV differ significantly in slope,
with the latter being much flatter but very similar to the radio light curve.


title:
Electronic Band Structure Mapping of Nanotube Transistors by Scanning
  Photocurrent Microscopy

abstract:
  Spatially resolved photocurrent measurements on carbon nanotube field-effect
transistors (CNFETs) operated in various transport regimes are reported. It is
demonstrated that the photocurrents measured at different biasing conditions
provide access to the electronic band structure profile of the nanotube
channel. A comparison of the profiles with the device switched into n- or
p-type states clearly evidences the impact of chemical doping from the ambient.
Moreover, we show that scanning photocurrent microscopy constitutes an
effective and facile technique for the quantitative determination of the
Schottky barrier height in such devices.


title:
Testing Gravity in the Outer Solar System: Results from Trans-Neptunian
  Objects

abstract:
  The inverse square law of gravity is poorly probed by experimental tests at
distances of ~ 10 AUs. Recent analysis of the trajectory of the Pioneer 10 and
11 spacecraft have shown an unmodeled acceleration directed toward the Sun
which was not explained by any obvious spacecraft systematics, and occurred
when at distances greater than 20 AUs from the Sun. If this acceleration
represents a departure from Newtonian gravity or is indicative of an additional
mass distribution in the outer solar system, it should be detectable in the
orbits of Trans-Neptunian Objects (TNOs). To place limits on deviations from
Newtonian gravity, we have selected a well observed sample of TNOs found
orbiting between 20 and 100 AU from the Sun. By examining their orbits with
modified orbital fitting software, we place tight limits on the perturbations
of gravity that could exist in this region of the solar system.


title:
Electron transport through single conjugated organic molecules: Basis
  set effects in ab initio calculations

abstract:
  We investigate electron transport through single conjugated molecules -
including benzenedithiol, oligo-phenylene-ethynylenes of different lengths, and
a ferrocene-containing molecule sandwiched between two gold electrodes with
different contact structures - by using a single-particle Green function method
combined with density functional theory calculation. We focus on the effect of
the basis set in the ab initio calculation. It is shown that the position of
the Fermi energy in the transport gap is sensitive to the molecule-lead charge
transfer which is affected by the size of basis set. This can dramatically
change, by orders of magnitude, the conductance for long molecules, though the
effect is only minor for short ones. A resonance around the Fermi energy tends
to pin the position of the Fermi energy and suppress this effect. The result is
discussed in comparison with experimental data.


title: Toroidal Orientifolds in IIA with General NS-NS Fluxes

abstract:
  Type IIA toroidal orientifolds offer a promising toolkit for model builders,
especially when one includes not only the usual fluxes from NS-NS and R-R field
strengths, but also fluxes that are T-dual to the NS-NS three-form flux. These
new ingredients are known as metric fluxes and non-geometric fluxes, and can
help stabilize moduli or can lead to other new features. In this paper we study
two approaches to these constructions, by effective field theory or by toroidal
fibers twisted over a toroidal base. Each approach leads us to important
observations, in particular the presence of D-terms in the four-dimensional
effective potential in some cases, and a more subtle treatment of the
quantization of the general NS-NS fluxes. Though our methods are general, we
illustrate each approach on the example of an orientifold of T^6/Z_4.


title: Hall Magnetohydrodynamics with Electron Inertia

abstract:
  Hall magnetohydrodynamic (MHD) with electron inertia is considered. A much
wider class of equilibrium solutions and the concomitant self-organization
aspects are discussed. The force-free field state B - J is shown to be a
consequence of the triple Beltrami condition.


title: eta Physics and phi Radiative Decays at Kloe

abstract:
  Here we present KLOE results on the phi meson decays in pi0 pi0 gamma, pi+
pi- gamma and eta pi0 gamma, the measurement of the ratio Br(phi to eta'
gamma)/Br(phi to eta gamma) with the estimate of the eta' gluonium content and
the measurement of the eta mass.


title: Dimension and enumeration of primitive ideals in quantum algebras

abstract:
  In this paper, we study the primitive ideals of quantum algebras supporting a
rational torus action. We first prove a quantum analogue of a Theorem of
Dixmier; namely, we show that the Gelfand-Kirillov dimension of primitive
factors of various quantum algebras is always even. Next we give a
combinatorial criterion for a prime ideal that is invariant under the torus
action to be primitive. We use this criterion to obtain a formula for the
number of primitive ideals in the algebra of $2\times n$ quantum matrices that
are invariant under the action of the torus. Roughly speaking, this can be
thought of as giving an enumeration of the points that are invariant under the
induced action of the torus in the ``variety of $2\times n$ quantum matrices''.


title:
Emergence and disappearance of micro-arcsecond structure in the
  scintillating quasar J1819+3845

abstract:
  The 4.8 GHz lightcurves of the scintillating intra-day variable quasar
J1819+3845 during 2004-5 exhibit sharp structure, down to a time scale of 15
minutes, that was absent from lightcurves taken prior to this period and from
the 2006 lightcurves. Analysis of the lightcurve power spectra show that the
variations must be due to the emergence of new structure in the source. The
power spectra yield a scattering screen distance of 3.8 +/- 0.3 pc for a
best-fit v_ISS=59 +/- 0.5 km/s or 2.0 +/- 0.3 pc for the scintillation velocity
reported by Dennett-Thorpe & de Bruyn (2003). The turbulence is required to be
exceptionally turbulent, with C_N^2 > 0.7 Delta L_pc^{-1} m^{-20/3} for
scattering material of thickness Delta L_{pc} pc along the ray path. The 2004
power spectrum can be explained in terms of a double source with a component
separation 240 +/- 15 microas in 2004.


title: Analytic Mechanics of Locally Conservative Physical Systems

abstract:
  The analysis of the dynamics of a material point perfectly constrained to a
submanifold of the three-dimensional euclidean space and subjected to a locally
conservative force's field, namely a force's field corresponding to a closed
but not necessarily exact differential form on such a submanifold, requires a
generalization of the Lagrangian and the Hamiltonian formalism that is here
developed.


title: Electron Temperature Evolution in Expanding Ultracold Neutral Plasmas

abstract:
  We have used the free expansion of ultracold neutral plasmas as a
time-resolved probe of electron temperature. A combination of experimental
measurements of the ion expansion velocity and numerical simulations
characterize the crossover from an elastic-collision regime at low initial
Gamma_e, which is dominated by adiabatic cooling of the electrons, to the
regime of high Gamma_e in which inelastic processes drastically heat the
electrons. We identify the time scales and relative contributions of various
processes, and experimentally show the importance of radiative decay and
disorder-induced electron heating for the first time in ultracold neutral
plasmas.


title: A discussion on particle number and quantum indistinguishability

abstract:
  The concept of individuality in quantum mechanics shows radical differences
from the concept of individuality in classical physics, as E. Schroedinger
pointed out in the early steps of the theory. Regarding this fact, some authors
suggested that quantum mechanics does not possess its own language, and
therefore, quantum indistinguishability is not incorporated in the theory from
the beginning. Nevertheless, it is possible to represent the idea of quantum
indistinguishability with a first order language using quasiset theory (Q). In
this work, we show that Q cannot capture one of the most important features of
quantum non individuality, which is the fact that there are quantum systems for
which particle number is not well defined. An axiomatic variant of Q, in which
quasicardinal is not a primitive concept (for a kind of quasisets called finite
quasisets), is also given. This result encourages the searching of theories in
which the quasicardinal, being a secondary concept, stands undefined for some
quasisets, besides showing explicitly that in a set theory about collections of
truly indistinguishable entities, the quasicardinal needs not necessarily be a
primitive concept.


title: Colloidal Gels: Equilibrium and Non-Equilibrium Routes

abstract:
  We attempt a classification of different colloidal gels based on
colloid-colloid interactions. We discriminate primarily between non-equilibrium
and equilibrium routes to gelation, the former case being slaved to
thermodynamic phase separation while the latter is individuated in the
framework of competing interactions and of patchy colloids. Emphasis is put on
recent numerical simulations of colloidal gelation and their connection to
experiments. Finally we underline typical signatures of different gel types, to
be looked in more details in experiments.


title: Non-commutative Donaldson-Thomas theory and the conifold

abstract:
  Given a quiver algebra A with relations defined by a superpotential, this
paper defines a set of invariants of A counting framed cyclic A-modules,
analogous to rank-1 Donaldson-Thomas invariants of Calabi-Yau threefolds. For
the special case when A is the non-commutative crepant resolution of the
threefold ordinary double point, it is proved using torus localization that the
invariants count certain pyramid-shaped partition-like configurations, or
equivalently infinite dimer configurations in the square dimer model with a
fixed boundary condition. The resulting partition function admits an infinite
product expansion, which factorizes into the rank-1 Donaldson-Thomas partition
functions of the commutative crepant resolution of the singularity and its
flop. The different partition functions are speculatively interpreted as
counting stable objects in the derived category of A-modules under different
stability conditions; their relationship should then be an instance of wall
crossing in the space of stability conditions on this triangulated category.


title: A Model for QCD at High Density and Large Quark Mass

abstract:
  We study the high density region of QCD within an effective model obtained in
the frame of the hopping parameter expansion and choosing Polyakov type of
loops as the main dynamical variables representing the fermionic matter. To get
a first idea of the phase structure, the model is analyzed in strong coupling
expansion and using a mean field approximation. In numerical simulations, the
model still shows the so-called sign problem, a difficulty peculiar to non-zero
chemical potential, but it permits the development of algorithms which ensure a
good overlap of the Monte Carlo ensemble with the true one. We review the main
features of the model and present calculations concerning the dependence of
various observables on the chemical potential and on the temperature, in
particular of the charge density and the diquark susceptibility, which may be
used to characterize the various phases expected at high baryonic density. We
obtain in this way information about the phase structure of the model and the
corresponding phase transitions and cross over regions, which can be considered
as hints for the behaviour of non-zero density QCD.


title: On the Formation and Dynamical Evolution of Planets in Binaries

abstract:
  Among the extrasolar planetary systems about 30 are located in a stellar
binary orbiting one of the stars, preferably the more massive primary. The
dynamical influence of the second companion alters firstly the orbital elements
of the forming protoplanet directly and secondly the structure of the disk from
which the planet formed which in turn will modify the planet's evolution. We
present detailed analysis of these effects and present new hydrodynamical
simulations of the evolution of protoplanets embedded in circumstellar disks in
the presence of a companion star, and compare our results to the system
$\gamma$ Cep. To analyse the early formation of planetary embryos, we follow
the evolution of a swarm of planetesimals embedded in a circumstellar disk.
Finally, we study the evolution of planets embedded in circumbinary disks.


title:
Equivalence principle and electromagnetic field: no birefringence, no
  dilaton, and no axion

abstract:
  The coupling of the electromagnetic field to gravity is discussed. In the
premetric axiomatic approach based on the experimentally well established
conservation laws of electric charge and magnetic flux, the Maxwell equations
are the same irrespective of the presence or absence of gravity. In this sense,
one can say that the charge "substratum" and the flux "substratum" are not
influenced by the gravitational field directly. However, the interrelation
between these fundamental substrata, formalized as the {\it spacetime relation}
H=H(F) between the 2-forms of the electromagnetic excitation H and the
electromagnetic field strength F, is affected by gravity. Thus the validity of
the equivalence principle for electromagnetism depends on the form of the
spacetime relation. We discuss the nonlocal and local linear constitutive
relations and demonstrate that the spacetime metric can be accompanied also by
skewon, dilaton, and axion fields. All these premetric companions of the metric
may eventually lead to a violation of the equivalence principle.


title:
Annotations to a certain passage of Descartes for finding the quadrature
  of the circle

abstract:
  Translation from the Latin of "Annotationes in locum quendam Cartesii ad
circuli quadraturam spectantem" (1763).
  The passage Euler is referring to is the "Excerpta" in part 6, p. 6 of
Descartes' 1701 "Opuscula posthuma".
  Before reading this paper I had not heard of the "quadratrix" before, and I
recommend learning a bit about it before reading this. I found Thomas Heath, "A
history of Greek mathematics", vol. I, chapter VII to be helpful, in particular
pp. 226-230. The quadratrix is a "mechanical curve" that can be used to rectify
the circle. The usual problem of squaring the circle is to construct a square
with the same area (or perimeter) as a given circle, in a finite number of
steps using compass and straightedge. Descartes worked in the reverse
direction: from a given square he constructed the radius of a circle with the
same perimeter, but in an infinite number of steps.
  In this paper Euler reconstructs Descartes' argument and develops some
consequences of it. Euler finds that \[ \sum_{n=0}^\infty \frac{1}{2^n} \tan
\frac{1}{2^n}\phi = \frac{1}{\phi} - 2\cot 2\phi. \] Integrating this yields \[
\prod_{n=1}^\infty \sec \frac{1}{2^n} \phi = \frac{2\phi}{\sin 2\phi}. \]
  I'd like to thank Davide Crippa from the University of Paris 7 for some
helpful back and forth about this paper.
  One of the only citations to this paper that I have found is in Pietro
Ferroni, De calculo integralium exercitatio mathematica, Allegrini, Florence,
1792, pp. xxi--xxiii. The full text of it is available on Google Books.


title: Combinatorial independence in measurable dynamics

abstract:
  We develop a fine-scale local analysis of measure entropy and measure
sequence entropy based on combinatorial independence. The concepts of measure
IE-tuples and measure IN-tuples are introduced and studied in analogy with
their counterparts in topological dynamics. Local characterizations of the
Pinsker von Neumann algebra and its sequence entropy analogue are given in
terms of combinatorial independence, l_1 geometry, and Voiculescu's completely
positive approximation entropy. Among the novel features of our local study is
the treatment of general discrete acting groups, with the structural assumption
of amenability in the case of entropy.


title: O-minimal cohomology: finiteness and invariance results

abstract:
  We prove that the cohomology groups of a definably compact set over an
o-minimal expansion of a group are finitely generated and invariant under
elementary extensions and expansions of the language. We also study the
cohomology of the intersection of a definable decreas-ing family of definably
compact sets, under the additional assumption that the o-minimal structure
expands a field.


title: Proposal for Higgs and Superpartner Searches at the LHCb Experiment

abstract:
  The spectrum of supersymmetric theories with R-parity violation are much more
weakly constrained than that of supersymmetric theories with a stable
neutralino. We investigate the signatures of supersymmetry at the LHCb
experiment in the region of parameter space where the neutralino decay leaves a
displaced vertex. We find sensitivity to squark production up to squark masses
of order 1 TeV. We note that if the Higgs decays to neutralinos in this
scenario, LHCb should see the lightest Higgs boson before ATLAS and CMS.


title: Global Topology from an Embedding

abstract:
  An embedding of chaotic data into a suitable phase space creates a
diffeomorphism of the original attractor with the reconstructed attractor.
Although diffeomorphic, the original and reconstructed attractors may not be
topologically equivalent. In a previous work we showed how the original and
reconstructed attractors can differ when the original is three-dimensional and
of genus-one type. In the present work we extend this result to
three-dimensional attractors of arbitrary genus. This result describes
symmetries exhibited by the Lorenz attractor and its reconstructions.


title: Self-doping instability of the Wigner-Mott insulator

abstract:
  We present a theory describing the mechanism for the two-dimensional (2D)
metal-insulator transition (MIT) in absence of disorder. A two-band Hubbard
model is introduced, describing vacancy-interstitial pair excitations within
the Wigner crystal. Kinetic energy gained by delocalizing such excitations is
found to lead to an instability of the insulator to self-doping above a
critical carrier concentration $n=n_c$, mapping the problem to a density-driven
Mott MIT. This mechanism provides a natural microscopic picture of several
puzzling experimental features, including the large effective mass enhancement,
the large resistivity drop, and the large positive magneto-resistance on the
metallic side of the transition. We also present a global phase diagram for the
clean 2D electron gas as a function of $n$ and parallel magnetic field
$B_{\shortparallel}$, which agrees well with experimental findings in ultra
clean samples.


title: Elastic Properties of Carbon nanotubes : An atomistic approach

abstract:
  Energetically the single sheet of graphite (graphene) is more stable than the
nanotube. The energy difference between the two systems can be directly related
to the strain energy involved in rolling up the graphene sheet to form the
nanotube. We have carried out first principle electronic structure calculations
and evaluated the strain energy as a function of the nanotube radius. The
dependence of the strain energy on the diameter of the nanotube has been found
by several groups to be welldescribed by a continuum elasticity model. We
attempt to examine why this is the case and show where atomistics enter the
description.


title:
The Macro Model of the Inequality Process and The Surging Relative
  Frequency of Large Wage Incomes

abstract: This paper presents a model of the dynamics of the wage income distribution.


title: Late-Type Red Supergiants: Too Cool for the Magellanic Clouds?

abstract:
  We have identified seven red supergiants (RSGs) in the Large Magellanic Cloud
(LMC) and four RSGs in the Small Magellanic Cloud (SMC), all of which have
spectral types that are considerably later than the average type observed in
their parent galaxy. Using moderate-resolution optical spectrophotometry and
the MARCS stellar atmosphere models, we determine their physical properties and
place them on the H-R diagram for comparison with the predictions of current
stellar evolutionary tracks. The radial velocities of these stars suggest that
they are likely all members of the Clouds rather than foreground dwarfs or halo
giants. Their locations in the H-R diagram also show us that those stars are
cooler than the current evolutionary tracks allow, appearing to the right of
the Hayashi limit, a region in which stars are no longer in hydrodynamic
equilibrium. These stars exhibit considerable variability in their V
magnitudes, and three of these stars also show changes in their effective
temperatures (and spectral types) on the time-scales of months. One of these
stars, [M2002] SMC 055188, was caught in an M4.5 I state, as late as that seen
in HV 11423 at its recent extreme: considerable later, and cooler, than any
other supergiant in the SMC. In addition, we find evidence of variable
extinction due to circumstellar dust and changes in the stars' luminosities,
also consistent with our recent findings for HV 11423 - when these stars are
hotter they are also dustier and more luminous. We suggest that these stars
have unusual properties because they are in an unstable (and short-lived)
evolutionary phase.


title: Reiter's properties (P_1) and (P_2) for locally compact quantum groups

abstract:
  A locally compact group $G$ is amenable if and only if it has Reiter's
property $(P_p)$ for $p=1$ or, equivalently, all $p \in [1,\infty)$, i.e.,
there is a net $(m_\alpha)_\alpha$ of non-negative norm one functions in
$L^p(G)$ such that $\lim_\alpha \sup_{x \in K} \| L_{x^{-1}} m_\alpha -
m_\alpha \|_p = 0$ for each compact subset $K \subset G$ ($L_{x^{-1}} m_\alpha$
stands for the left translate of $m_\alpha$ by $x^{-1}$). We extend the
definitions of properties $(P_1)$ and $(P_2)$ from locally compact groups to
locally compact quantum groups in the sense of J. Kustermans and S. Vaes. We
show that a locally compact quantum group has $(P_1)$ if and only if it is
amenable and that it has $(P_2)$ if and only if its dual quantum group is
co-amenable. As a consequence, $(P_2)$ implies $(P_1)$.


title: Why prove things?

abstract: We illustrate the concept of mathematical proof.


title: Bulk and nano GaN: Role of Ga d states

abstract:
  We have studied the role of Ga 3d states in determining the properties of
bulk as well as nanoparticles of GaN using PAW potentials. A significant
contribution of the Ga d states in the valence band is found to arise from the
interaction of Ga 4d states with the dominantly N p states making up the
valence band. The errors arising from not treating the Ga 3d states as a part
of the valence are found to be similar, ~ 1%, for bulk as well as for
nanoclusters of GaN.


title: Weak and Repulsive Casimir Force in Piston Geometries

abstract:
  We study the Casimir force in piston-like geometries semiclassically. The
force on the piston is finite and physical, but to leading semiclassical
approximation depends strongly on the shape of the surrounding cavity. Whereas
this force is attractive for pistons in a parallelepiped with flat cylinder
head, for which the semiclassical approximation by periodic orbits is exact,
this approximation to the force on the piston vanishes for a semi-cylindrical
head and becomes repulsive for a cylinder of circular cross section with a
hemispherical head. In leading semiclassical approximation the sign of the
force is related to the generalized Maslov index of short periodic orbits
between the piston and its casing.


title:
The Minimum Gap-opening Planet Mass in an Irradiated Circumstellar
  Accretion Disk

abstract:
  We consider the minimum mass planet, as a function of radius, that is capable
of opening a gap in an $\alpha$-accretion disk. We estimate that a half Jupiter
mass planet can open a gap in a disk with accretion rate $\dot M \la 10^{-8}
M_\odot$/yr for viscosity parameter $\alpha =0.01$, and Solar mass and
luminosity. The minimum mass is approximately proportional to $\dot M^{0.48}
\alpha^{0.8} M_*^{0.42} L_*^{-0.08}$. This estimate can be used to rule out the
presence of massive planets in gapless accretion disks. We identify two radii
at which an inwardly migrating planet may become able to open a gap and so slow
its migration; the radius at which the heating from viscous dissipation is
similar to that from stellar radiation in a flared disk, and the radius at
which the disk has optical depth order 1 in a self-shadowed disk. If a gap
opening planet cuts off disk accretion allowing the formation of a central hole
or clearing in the disk then we would estimate that the clearing radius would
approximately be proportional to the stellar mass.


title: Non-Commutative Complete Mellin Representation for Feynman Amplitudes

abstract:
  We extend the complete Mellin (CM) representation of Feynman amplitudes to
the non-commutative quantum field theories. This representation is a versatile
tool. It provides a quick proof of meromorphy of Feynman amplitudes in
parameters such as the dimension of space-time. In particular it paves the road
for the dimensional renormalization of these theories. This complete Mellin
representation also allows the study of asymptotic behavior under rescaling of
arbitrary subsets of external invariants of any Feynman amplitude.


title:
Space Velocities of Southern Globular Clusters. V. A Low Galactic
  Latitude Sample

abstract:
  We have measured the absolute proper motions of globular clusters NGC 2808,
3201, 4372, 4833, 5927 and 5986. The proper motions are on the Hipparcos system
and they are the first determinations ever made for these low Galactic latitude
clusters. The proper motion uncertainties range from 0.3 to 0.5 mas/yr. The
inferred orbits indicate that 1) the single metal rich cluster in our sample,
NGC 5927, dynamically belongs to the thick disk, 2) the remaining metal poor
clusters have rather low-energy orbits of high eccentricity; among these, there
appear to be two "pairs" of dynamically associated clusters, 3) the most
energetic cluster in our sample, NGC 3201 is on a highly retrograde orbit --
which had already been surmised from its radial velocity alone -- with an
apocentric distance of 22 kpc, and 4) none of the metal poor clusters appear to
be associated with the recently detected SDSS streams, or with the Monoceros
structure.
  These are the first results of the Southern Proper-Motion Program (SPM) where
the second-epoch observations are taken with the CCD camera system recently
installed on the double astrograph at El Leoncito, Argentina.


title: Radiative heavy quark energy loss in a dynamical QCD medium

abstract:
  The computation of radiative energy loss in a dynamically screened QCD medium
is a key ingredient for obtaining reliable predictions for jet quenching in
ultra-relativistic heavy ion collisions. We calculate, to first order in the
opacity, the energy loss suffered by a heavy quark traveling through an
infinite and time-independent QCD medium and show that the result for a
dynamical medium is almost twice that obtained previously for a medium
consisting of randomly distributed static scattering centers. A quantitative
description of jet suppression in RHIC and LHC experiments thus must correctly
account for the dynamics of the medium's constituents.


title:
Semidensities, Second-Class Constraints and Conversion in Anti-Poisson
  Geometry

abstract:
  We consider Khudaverdian's geometric version of a Batalin-Vilkovisky (BV)
operator \Delta_E in the case of a degenerate anti-Poisson manifold. The
characteristic feature of such an operator (aside from being a Grassmann-odd,
nilpotent, second-order differential operator) is that it sends semidensities
to semidensities. We find a local formula for the \Delta_E operator in
arbitrary coordinates. As an important application of this setup, we consider
the Dirac antibracket on an antisymplectic manifold with antisymplectic
second-class constraints. We show that the entire Dirac construction, including
the corresponding Dirac BV operator \Delta_{E_D}, exactly follows from
conversion of the antisymplectic second-class constraints into first-class
constraints on an extended manifold.


title: Correcting second-order contamination in low-resolution spectra

abstract:
  An empirical method for correcting low-resolution astronomical spectra for
second-order contamination is presented. The method was developed for
correcting spectra obtained with grism #4 of the ALFOSC spectrograph at the
Nordic Optical Telescope and the performance is demonstrated on spectra of two
nearby bright Type Ia supernovae.


title: Mitigation of loss within a molecular Stark decelerator

abstract:
  The transverse motion inside a Stark decelerator plays a large role in the
total efficiency of deceleration. We differentiate between two separate regimes
of molecule loss during the slowing process. The first mechanism involves
distributed loss due to coupling of transverse and longitudinal motion, while
the second is a result of the rapid decrease of the molecular velocity within
the final few stages. In this work, we describe these effects and present means
for overcoming them. Solutions based on modified switching time sequences with
the existing decelerator geometry lead to a large gain of stable molecules in
the intermediate velocity regime, but fail to address the loss at very low
final velocities. We propose a new decelerator design, the quadrupole-guiding
decelerator, which eliminates distributed loss due to transverse/longitudinal
couplings throughout the slowing process and also exhibits gain over normal
deceleration to the lowest velocities.


title:
Comment on "Orbital stability of solitary wave solutions for an
  interaction equation of short and long dispersive waves"

abstract:
  J. Angulo and J. F. Montenegro (J. Differential Equations 174 (2001), no. 1,
181-199) published a paper about nonlinear stability of solitary waves for an
interaction system between a long internal wave and a short surface wave in a
two layer fluid considering that the fluid depth of the lower layer is
sufficiently large in comparison with the wavelength of the internal wave. In
this note, we show that in a critical step during the proof of Lemma 2.4 in the
above mentioned paper, there is a claim used by the authors which fails to be
true. Lemma 2.4 is crucial for the proof of Lemma 2.7, and for the proof of
stability in Theorem 2.1 in the paper before mentioned.


title: Terrestrial Planet Formation in Binary Star Systems

abstract:
  A binary star system is the most common result of the star formation process,
and binary companions can disrupt both the formation of terrestrial planets and
their long term prospects for stability. We present results from a large set of
numerical simulations of the final stages of terrestrial planet formation -
from Moon- to Mars-sized planetary embryos to planets - in main-sequence binary
star systems. We examine planetary accretion around both stars ('P-type'
circumbinary orbits) or individual stars ('S-type' orbits) in binary systems,
including terrestrial planet formation around each star in Alpha Centauri AB,
the closest binary star system to the Sun. For comparison, we also simulate
planetary growth from the same initial disk placed in the Sun-Jupiter-Saturn
system and also around the Sun with neither giant planets nor a stellar
companion perturbing the system. Our simulations show that giant and stellar
companions not only truncate the disk, but hasten the accretion process by
stirring up the planetary embryos to higher eccentricities and inclinations.
Terrestrial planets similar to those in our Solar System formed around
individual stars in simulations with the binary periastron (closest approach)
greater than about 5 AU. Terrestrial planet growth within circumbinary disks
was uninhibited around inner binary star systems with binary apastrons (maximum
separation) less than ~0.2 AU. Results from our simulations can be scaled for
different stellar and disk parameters. Approximately 50 - 60% of binary star
systems - from contact binaries to separations of nearly a parsec - satisfy
these constraints. Given that the galaxy contains more than 100 billion star
systems, a large number of systems remain habitable based on the dynamic
considerations of this research.


title: Admissible orders of Jordan loops

abstract:
  A commutative loop is Jordan if it satisfies the identity $x^2 (y x) = (x^2
y) x$. Using an amalgam construction and its generalizations, we prove that a
nonassociative Jordan loop of order $n$ exists if and only if $n\geq 6$ and
$n\neq 9$. We also consider whether powers of elements in Jordan loops are
well-defined, and we construct an infinite family of finite simple
nonassociative Jordan loops.


title: The fundamental theorem of complex multiplication

abstract:
  The goal of this expository article is to present a proof that is as direct
and elementary as possible of the fundamental theorem of complex multiplication
(Shimura, Taniyama, Langlands, Tate, Deligne et al.).
  The article is a revision of part of my manuscript, Complex Multiplication,
April 7, 2006.


title:
Dirac equation exact solutions for generalized asymmetrical Hartmann
  potentials

abstract:
  In this work we solve the Dirac equation by constructing the exact bound
state solutions for a mixing of vector and scalar generalized Hartmann
potentials. This is done provided the vector potential is equal to or minus the
scalar potential. The cases of some quasi-exactly solvable and Morse-like
potentials are briefly commented.


title: Mass in the Hyperbolic Plane

abstract:
  The notions of mass and center of mass are extended to laminae of the
hyperbolic plane. The resulting formulae contain many surprises.


title:
The Piezoresponse Force Microscopy of surface layers and thin films:
  effective response and resolution function

abstract:
  Signal formation mechanism of Piezoresponse Force Microscopy of piezoelectric
surface layers and thin films on stiff and elastically matched substrates is
analyzed and thickness dependence of effective piezoelectric response, object
transfer function components and Rayleigh two-point resolution are derived.
Obtained exact series and simple Pade approximations can be applied for the
effective piezoresponse analytical calculations in the case of films capped on
different substrates. The effective piezoresponse is thickness dependent for
piezoelectric films on substrates with low dielectric permittivity (extrinsic
size effect), whereas the thickness dependence is essentially suppressed for
giant permittivity or metallic substrates. Thus implications of analysis for
ferroelectric data storage and device applications are discussed.


title:
The symplectic geometry of cotangent bundles from a categorical
  viewpoint

abstract:
  We describe various approaches to understanding Fukaya categories of
cotangent bundles. All of the approaches rely on introducing a suitable class
of noncompact Lagrangian submanifolds. We review the work of Nadler-Zaslow
(math/0604379, math/0612399) and the authors (math/0701783), before discussing
a new approach using family Floer cohomology and the ``wrapped Fukaya
category''. The latter, inspired by Viterbo's symplectic homology, emphasises
the connection to loop spaces, hence seems particularly suitable when trying to
extend the existing theory beyond the simply-connected case.


title:
On the Possibility of Observing the Shapiro Effect for Pulsars in
  Globular Clusters

abstract:
  For pulsars in globular clusters, we suggest using observations of the
relativistic time delay of their radiation in the gravitational eld of a
massive body (the Shapiro effect) located close to the line of sight to detect
and identify invisible compact objects and to study the distribution of both
visible and dark matter in globular clusters and various components of the
Galaxy. We have derived the dependences of the event probability on the
Galactic latitude and longitude of sources for two models of the mass
distribution in the Galaxy: the classical Bahcall-Soneira model and the more
recent Dehnen-Binney model. Using three globular clusters (M15, 47 Tuc, Terzan
5) as an example, we show that the ratios of the probability of the events due
to the passages of massive Galactic objects close to the line of sight to the
parameter f2 for pulsars in the globular clusters 47 Tuc and M15 are comparable
to those for close passages of massive objects in the clusters themselves and
are considerably higher than those for the cluster Terzan 5. We have estimated
the rates of such events. We have determined the number of objects near the
line of sight toward the pulsar that can produce a modulation of its pulse
arrival times characteristic of the effect under consideration; the population
of brown dwarfs in the Galactic disk, whose concentration is comparable to that
of the disk stars, has been taken into account for the first time.


title:
Topologically Massive Gauge Theories and their Dual Factorised Gauge
  Invariant Formulation

abstract:
  There exists a well-known duality between the Maxwell-Chern-Simons theory and
the self-dual massive model in 2+1 dimensions. This dual description has been
extended to topologically massive gauge theories (TMGT) in any dimension. This
Letter introduces an unconventional approach to the construction of this type
of duality through a reparametrisation of the master theory action. The dual
action thereby obtained preserves the same gauge symmetry structure as the
original theory. Furthermore, the dual action is factorised into a propagating
sector of massive gauge invariant variables and a sector with gauge variant
variables defining a pure topological field theory. Combining results obtained
within the Lagrangian and Hamiltonian formulations, a new completed structure
for a gauge invariant dual factorisation of TMGT is thus achieved.


title: Graphs on surfaces and Khovanov homology

abstract:
  Oriented ribbon graphs (dessins d'enfant) are graphs embedded in oriented
surfaces. A quasi-tree of a ribbon graph is a spanning subgraph with one face,
which is described by an ordered chord diagram. We show that for any link
diagram $L$, there is an associated ribbon graph whose quasi-trees correspond
bijectively to spanning trees of the graph obtained by checkerboard coloring
$L$. This correspondence preserves the bigrading used for the spanning tree
model of Khovanov homology, whose Euler characteristic is the Jones polynomial
of $L$. Thus, Khovanov homology can be expressed in terms of ribbon graphs,
with generators given by ordered chord diagrams.


title: Engineering fidelity echoes in Bose-Hubbard Hamiltonians

abstract:
  We analyze the fidelity decay for a system of interacting bosons described by
a Bose-Hubbard Hamiltonian. We find echoes associated with "non-universal"
structures that dominate the energy landscape of the perturbation operator.
Despite their classical origin, these echoes persist deep into the quantum
(perturbative) regime and can be described by an improved random matrix
modeling. In the opposite limit of strong perturbations (and high enough
energies), classical considerations reveal the importance of self-trapping
phenomena in the echo efficiency.