title: Air Traffic Flow Management

abstract:
  Air Traffic Flow Management is the regulation of air traffic in order to
avoid exceeding airport or flight sector capacity in handling traffic, and to
ensure that available capacity is used efficiently. We have tried to explore
the logic behind the claims by Bertsimas et.al about integral solutions to the
LP relaxation of the Traffic Flow Management Problem(TFMP). Polyhedral theory
only indicates that the stronger TFMP formulation of Bertsimas et.al might lead
to integral solutions in some cases. Our computations indicate that the
encouraging results reported by Bertsimas et.al are not merely fortuitous or
due to their specific data set. Indeed, we found that the TFMP had integral
solutions even in case of artificial data sets generated to include severe
conflicts in the flight schedules. In our limited tests with 4-5 scenarios, we
obtained non-integral solutions only once. This is of significant practical
importance because, the LP relaxation can be solved even on small machines with
low memory and processor speed.


title: Groups with the same cohomology as their profinite completions

abstract:
  For any positive integer $n$, $\mathcal{A}_n$ is the class of all groups $G$
such that, for $0\leq i\leq n$, $H^i(\hat{G},A)\cong H^i(G,A)$ for every finite
discrete $\hat{G}$-module $A$. We describe certain types of free products with
amalgam and HNN extensions that are in some of the classes $\mathcal{A}_n$. In
addition, we investigate the residually finite groups in the class
$\mathcal{A}_2$.


title: The escaping set of a quasiregular mapping

abstract:
  We show that if the maximum modulus of a quasiregular mapping f grows
sufficiently rapidly then there exists a non-empty escaping set I(f) consisting
of points whose forward orbits under iteration tend to infinity. This set I(f)
has an unbounded component but, in contrast to the case of entire functions on
the complex plane, the closure of I(f) may have a bounded component.


title:
Similarities and Differences between Coronal Holes and the Quiet Sun:
  Are Loop Statistics the Key?

abstract:
  Coronal holes (CH) emit significantly less at coronal temperatures than
quiet-Sun regions (QS), but can hardly be distinguished in most chromospheric
and lower transition region lines. A key quantity for the understanding of this
phenomenon is the magnetic field. We use data from SOHO/MDI to reconstruct the
magnetic field in coronal holes and the quiet Sun with the help of a potential
magnetic model. Starting from a regular grid on the solar surface we then trace
field lines, which provide the overall geometry of the 3D magnetic field
structure. We distinguish between open and closed field lines, with the closed
field lines being assumed to represent magnetic loops. We then try to compute
some properties of coronal loops. The loops in the coronal holes (CH) are found
to be on average flatter than in the QS. High and long closed loops are
extremely rare, whereas short and low-lying loops are almost as abundant in
coronal holes as in the quiet Sun. When interpreted in the light of loop
scaling laws this result suggests an explanation for the relatively strong
chromospheric and transition region emission (many low-lying, short loops), but
the weak coronal emission (few high and long loops) in coronal holes. In spite
of this contrast our calculations also suggest that a significant fraction of
the cool emission in CHs comes from the open flux regions. Despite these
insights provided by the magnetic field line statistics further work is needed
to obtain a definite answer to the question if loop statistics explain the
differences between coronal holes and the quiet Sun.


title:
CPT violation in long baseline neutrino experiments: a three flavor
  analysis

abstract:
  We explore possible signals of CPT violation in neutrinos in the complete
three-flavor framework. Employing a systematic expansion in small parameters,
we analytically estimate the CPT violating contributions to the survival
probabilities of $\nu_\mu, \bar{\nu}_\mu, \nu_e$ and $\bar{\nu}_e$. The results
indicate that, in spite of the large number of CPT violating parameters, only a
small number of combinations are relevant for oscillation experiments. We
identify the combinations that can be constrained at the long baseline
experiments, and show that their contribution to the neutrino Hamiltonian can
be bounded to $< 10^{-23}$ GeV, by considering the NOvA experiment for the muon
sector, and neutrino factories for the electron sector.This formalism also
allows us to translate the bounds on the parameters describing non-standard
interactions of neutrinos into the bounds on CPT violating quantities.


title: Attosecond light pulse induced photo-association

abstract:
  We explore stimulated photo-association in the context of attosecond
pump-probe schemes of atomic matter. An attosecond pulse -- the probe -- is
used to induce photo-association of an electronic wave packet which had been
created before, typically with an attosecond pump pulse at an atomic center
different from the one of photo-association. We will show that the electron
absorption is maximal for a certain delay between the pulses. Two ways of
enhancing and controlling stimulated photo-association are proposed, namely
using an additional infrared pulse to steer the electronic wave packet and
using a train of attosecond pulses instead of a single pair. A direct
application of ultrafast stimulated photo-association is the measurement of
atomic distances.


title: Analytic torsions on contact manifolds

abstract:
  We propose a definition for analytic torsion of the contact complex on
contact manifolds. We show it coincides with Ray-Singer torsion on any
3-dimensional CR Seifert manifold equipped with a unitary representation. In
this particular case we compute it and relate it to dynamical properties of the
Reeb flow. In fact the whole spectral torsion function we consider may be
interpreted on CR Seifert manifolds as a purely dynamical function through
Selberg-type trace formulae.


title:
Optimization code with weighting function for the reconstruction of
  coronal magnetic fields

abstract:
  We developed a code for the reconstruction of nonlinear force-free and
non-force-free coronal magnetic fields. The 3D magnetic field is computed
numerically with the help of an optimization principle. The force-free and
non-force-free codes are compiled in one program. The force-free approach needs
photospheric vector magnetograms as input. The non-force-free code additionally
requires the line-of-sight integrated coronal density distribution in
combination with a tomographic inversion code. Previously the optimization
approach has been used to compute magnetic fields using all six boundaries of a
computational box. Here we extend this method and show how the coronal magnetic
field can be reconstructed only from the bottom boundary, where the boundary
conditions are measured with vector magnetographs. The program is planed for
use within the Stereo mission.


title:
Gisin's theorem for two d-dimensional systems based on the
  Collins-Gisin-Linden-Masser-Popescu inequality

abstract:
  In this Rapid Communication, we show analytically that all pure entangled
states of two d-dimensional systems (qudits) violate the
Collins-Gisin-Linden-Masser-Popoescu (CGLMP) inequality. Thus one has the
Gisin's theorem for two qudits.


title:
Interatomic van der Waals potential in the presence of a
  magneto-electric sphere

abstract:
  On the basis of a general formula obtained earlier via fourth-order
erturbation theory within the framework of macroscopic quantum electrodynamics,
the van der Waals potential between two neutral, unpolarized, ground-state
atoms in the presence of a homogeneous, dispersing and absorbing
magnetoelectric sphere is studied. When the radius of the sphere becomes
sufficiently large, the result asymptotically agrees with that for two atoms
near a planar interface. In the opposite limit of a very small sphere, the
sphere can effectively be regarded as being a third ground-state atom, and the
nonadditive three-atom van der Waals potential is recovered. To illustrate the
effect of a sphere of arbitrary radius, numerical results are presented for the
triangular arrangement where the atoms are at equidistance from the sphere, and
for the linear arrangement where the atoms and the sphere are aligned along a
straight line. As demonstrated, the enhancement or reduction of the interaction
potential in the presence of purely electric or magnetic spheres can be
physically understood in terms of image charges.


title: Phases in optical lattices vs. Coulomb frustrated HTc cuprates

abstract:
  Fermionic atoms in 2D optical lattices and electrons in HTc cuprates may both
be described by the Hubbard model. However, if Coulomb frustration is
responsible for the striped phases in 2D cuprates the phase diagrams will
differ markedly. Two representative scenarios are described by a simple stripe
model without phase separation and a mean field model with phase separation in
the absence of Coulomb frustration. When Coulomb frustrated both models display
antiferromagnetism (AF) and stripe phases with d-wave superfluidity, whereas
neutral atoms in optical lattices will only do so in the stripe model. Radii
and densities of the various phases in harmonically confined optical lattices
are calculated for the two models and have very different Mott plateaus and
density discontinuities. We discuss observation of antiferromagnetic, stripe
and superfluid phases in density and momentum distributions and correlations
from time-of-flight experiments.


title: Magnetic quantum oscillations in doped antiferromagnetic insulators

abstract:
  Energy spectrum of electrons (holes) doped into a two-dimensional
antiferromagnetic insulator is quantized in an external magnetic field of
arbitrary direction. A peculiar dependence of de Haas-van Alphen (dHvA) or
Shubnikov-de Haas (SdH) magneto-oscillation amplitudes on the azimuthal
in-plane angle from the magnetization direction and on the polar angle from the
out-of-plane direction is found, which can be used as a sensitive probe of the
antiferromagnetic order in doped Mott-Hubbard, spin-density wave (SDW), and
conventional band-structure insulators.


title:
Optical depth for VHE gamma-rays from distant sources from a generic EBL
  density

abstract:
  Very-high-energy (VHE; E>100GeV) gamma-rays from distant sources suffer
attenuation through pair-production with low energy photons from the diffuse
extragalactic photon fields in the ultraviolet (UV) to far-infrared (FIR)
(commonly referred to as Extragalactic Background Light; EBL). When modeling
the intrinsic spectra of the VHE gamma-ray sources it is crucial to correctly
account for the attenuation. Unfortunately, direct measurements of the EBL are
difficult and the knowledge about the EBL over certain wavelength ranges is
poor. To calculate the EBL attenuation usually predictions from theoretical
models are used. Recently, the limits on the EBL from direct and indirect
methods have narrowed down the possible EBL range and many of the previous
models are in conflict with these limits. We propose a new generic EBL density
(not a complete model), which is in compliance with the new EBL limits. EBL
evolution with redshift is included in the calculation in a very simple but
effective ad-hoc way. Properties of this generic EBL are discussed.


title: About the true type of smoothers

abstract:
  We employ the variational formulation and the Euler-Lagrange equations to
study the steady-state error in linear non-causal estimators (smoothers). We
give a complete description of the steady-state error for inputs that are
polynomial in time. We show that the steady-state error regime in a smoother is
similar to that in a filter of double the type. This means that the
steady-state error in the optimal smoother is significantly smaller than that
in the Kalman filter. The results reveal a significant advantage of smoothing
over filtering with respect to robustness to model uncertainty.


title: Compressed Sensing in Astronomy

abstract:
  Recent advances in signal processing have focused on the use of sparse
representations in various applications. A new field of interest based on
sparsity has recently emerged: compressed sensing. This theory is a new
sampling framework that provides an alternative to the well-known Shannon
sampling theory. In this paper we investigate how compressed sensing (CS) can
provide new insights into astronomical data compression and more generally how
it paves the way for new conceptions in astronomical remote sensing. We first
give a brief overview of the compressed sensing theory which provides very
simple coding process with low computational cost, thus favoring its use for
real-time applications often found on board space mission. We introduce a
practical and effective recovery algorithm for decoding compressed data. In
astronomy, physical prior information is often crucial for devising effective
signal processing methods. We particularly point out that a CS-based
compression scheme is flexible enough to account for such information. In this
context, compressed sensing is a new framework in which data acquisition and
data processing are merged. We show also that CS provides a new fantastic way
to handle multiple observations of the same field view, allowing us to recover
information at very low signal-to-noise ratio, which is impossible with
standard compression methods. This CS data fusion concept could lead to an
elegant and effective way to solve the problem ESA is faced with, for the
transmission to the earth of the data collected by PACS, one of the instruments
on board the Herschel spacecraft which will be launched in 2008.


title: The iron abundance of the Magellanic Bridge

abstract:
  High-resolution HST ultra-violet spectra for five B-type stars in the
Magellanic Bridge and in the Large and Small Magellanic Clouds have been
analysed to estimate their iron abundances. Those for the Clouds are lower than
estimates obtained from late-type stars or the optical lines in B-type stars by
approximately 0.5 dex. This may be due to systematic errors possibly arising
from non-LTE effects or from errors in the atomic data as similar low Fe
abundances having previously been reported from the analysis of the
ultra-violet spectra of Galactic early-type stars. The iron abundance estimates
for all three Bridge targets appear to be significantly lower than those found
for the SMC and LMC by approximately -0.5 dex and -0.8 dex respectively and
these differential results should not be affected by any systematic errors
present in the absolute abundance estimates. These differential iron abundance
estimates are consistent with the underabundances for C, N, O, Mg and Si of
approximately -1.1 dex relative to our Galaxy previously found in our Bridge
targets. The implications of these very low metal abundances for the Magellanic
Bridge are discussed in terms of metal deficient material being stripped from
the SMC.


title: Essential selfadjointness of the graph-Laplacian

abstract:
  We study the operator theory associated with such infinite graphs $G$ as
occur in electrical networks, in fractals, in statistical mechanics, and even
in internet search engines. Our emphasis is on the determination of spectral
data for a natural Laplace operator associated with the graph in question. This
operator $\Delta$ will depend not only on $G$, but also on a prescribed
positive real valued function $c$ defined on the edges in $G$. In electrical
network models, this function $c$ will determine a conductance number for each
edge. We show that the corresponding Laplace operator $\Delta$ is automatically
essential selfadjoint. By this we mean that $\Delta$ is defined on the dense
subspace $\mathcal{D}$ (of all the real valued functions on the set of vertices
$G^{0}$ with finite support) in the Hilbert space $l^{2}% (G^{0})$. The
conclusion is that the closure of the operator $\Delta$ is selfadjoint in
$l^{2}(G^{0})$, and so in particular that it has a unique spectral resolution,
determined by a projection valued measure on the Borel subsets of the infinite
half-line. We prove that generically our graph Laplace operator
$\Delta=\Delta_{c}$ will have continuous spectrum. For a given infinite graph
$G$ with conductance function $c$, we set up a system of finite graphs with
periodic boundary conditions such the finite spectra, for an ascending family
of finite graphs, will have the Laplace operator for $G$ as its limit.


title:
Glassy magnetic behavior induced by $Cu^{2+}$ substitution in frustrated
  antiferromagnet $ZnCr_2O_4$

abstract:
  Structure and magnetic properties of the compounds $Zn_{1-x}Cu_xCr_2O_4$
(ZCCO) are investigated systematically. A structural phase transition from
space-group symmetry $Fd3m$ to $I4_1/amd$ is observed in ZCCO. The critical
value of the doping, $x$, appears at $0.58\sim 0.62$ through the appearance of
a splitting of diffraction peaks at room temperature. Measurements of dc
magnetization, ac susceptibility, memory effect and exchange bias-like
(EB-like) effect have been performed to reveal the glassy magnetic behaviors of
ZCCO. The system with $x\leqslant 0.50$ is suggested as a spin glass-like
(SG-like) of magnetic characterization whereas doping values of $0.58\leqslant
x\leqslant 0.90$ defines the system as a $"$cluster glass-like$"$ (CG-like)
with unidirectional anisotropy. The Cu content suppresses the geometrical
frustration of $ZnCr_2O_4$, which may correlate with the pinning effect of Cu
sublattice on Cr sublattice to a preferential direction.


title:
Pulsational and evolutionary analysis of the double-mode RR Lyrae star
  BS Com

abstract:
  We derive the basic physical parameters of the field double-mode RR Lyrae
star BS Com from its observed periods and the requirement of consistency
between the pulsational and evolutionary constraints. By using the current
solar-scaled horizontal branch evolutionary models of Pietrinferni et al.
(2004) and our linear non-adiabatic purely radiative pulsational models, we get
M/M(Sun) = 0.698 +/- 0.004, log(L/L(Sun)) = 1.712 +/- 0.005, T(eff) = 6840 +/-
14 K, [Fe/H] = -1.67 +/- 0.01, where the errors are standard deviations
assuming uniform age distribution along the full range of uncertainty in age.
The last two parameters are in a good agreement with the ones derived from the
observed BVIc colours and the updated ATLAS9 stellar atmosphere models. We get
T(eff) = 6842 +/- 10 K, [Fe/H] = -1.58 +/- 0.11, where the errors are purely
statistical ones. It is remarkable that the derived parameters are nearly
independent of stellar age at early evolutionary stages. Later stages,
corresponding to the evolution toward the asymptotic giant branch are most
probably excluded because the required high temperatures are less likely to
satisfy the constraints posed by the colours. We also show that our conclusions
are only weakly sensitive to nonlinear period shifts predicted by current
hydrodynamical models.


title: Silica-on-Silicon Waveguide Quantum Circuits

abstract:
  Quantum technologies based on photons are anticipated in the areas of
information processing, communication, metrology, and lithography. While there
have been impressive proof-of-principle demonstrations in all of these areas,
future technologies will likely require an integrated optics architecture for
improved performance, miniaturization and scalability. We demonstrated high-
fidelity silica-on-silicon integrated optical realizations of key quantum
photonic circuits, including two-photon quantum interference with a visibility
of 94.8(5)%; a controlled-NOT gate with logical basis fidelity of 94.3(2)%; and
a path entangled state of two photons with fidelity >92%.


title: Fault-Tolerant Partial Replication in Large-Scale Database Systems

abstract:
  We investigate a decentralised approach to committing transactions in a
replicated database, under partial replication. Previous protocols either
re-execute transactions entirely and/or compute a total order of transactions.
In contrast, ours applies update values, and orders only conflicting
transactions. It results that transactions execute faster, and distributed
databases commit in small committees. Both effects contribute to preserve
scalability as the number of databases and transactions increase. Our algorithm
ensures serializability, and is live and safe in spite of faults.


title: Rescattering for extended atomic systems

abstract:
  Laser-driven rescattering of electrons is the basis of many strong-field
phenomena in atoms and molecules. Here, we will show how this mechanism
operates in extended atomic systems, giving rise to effective energy
absorption. Rescattering from extended systems can also lead to energy loss,
which in its extreme form results in non-linear photo-association.
Intense-laser interaction with atomic clusters is discussed as an example. We
explain fast electron emission, seen in experimental and numerically obtained
spectra, by rescattering of electrons at the highly charged cluster.


title:
An improved global analysis of nuclear parton distribution functions
  including RHIC data

abstract:
  We present an improved leading-order global DGLAP analysis of nuclear parton
distribution functions (nPDFs), supplementing the traditionally used data from
deep inelastic lepton-nucleus scattering and Drell-Yan dilepton production in
proton-nucleus collisions, with inclusive high-$p_T$ hadron production data
measured at RHIC in d+Au collisions. With the help of an extended definition of
the $\chi^2$ function, we now can more efficiently exploit the constraints the
different data sets offer, for gluon shadowing in particular, and account for
the overall data normalization uncertainties during the automated $\chi^2$
minimization. The very good simultaneous fit to the nuclear hard process data
used demonstrates the feasibility of a universal set of nPDFs, but also
limitations become visible. The high-$p_T$ forward-rapidity hadron data of
BRAHMS add a new crucial constraint into the analysis by offering a direct
probe for the nuclear gluon distributions -- a sector in the nPDFs which has
traditionally been very badly constrained. We obtain a strikingly stronger
gluon shadowing than what has been estimated in previous global analyses. The
obtained nPDFs are released as a parametrization called EPS08.


title: Families of spherical caps: spectra and ray limit

abstract:
  We consider a family of surfaces of revolution ranging between a disc and a
hemisphere, that is spherical caps. For this family, we study the spectral
density in the ray limit and arrive at a trace formula with geodesic polygons
describing the spectral fluctuations. When the caps approach the hemisphere the
spectrum becomes equally spaced and highly degenerate whereas the derived trace
formula breaks down. We discuss its divergence and also derive a different
trace formula for this hemispherical case. We next turn to perturbative
corrections in the wave number where the work in the literature is done for
either flat domains or curved without boundaries. In the present case, we
calculate the leading correction explicitly and incorporate it into the
semiclassical expression for the fluctuating part of the spectral density. To
the best of our knowledge, this is the first calculation of such perturbative
corrections in the case of curvature and boundary.


title:
d=4 Black Hole Attractors in N=2 Supergravity with Fayet-Iliopoulos
  Terms

abstract:
  We generalize the description of the d=4 Attractor Mechanism based on an
effective black hole (BH) potential to the presence of a gauging which does not
modify the derivatives of the scalars and does not involve hypermultiplets. The
obtained results do not rely necessarily on supersymmetry, and they can be
extended to d>4, as well. Thence, we work out the example of the stu model of
N=2 supergravity in the presence of Fayet-Iliopoulos terms, for the
supergravity analogues of the magnetic and D0-D6 BH charge configurations, and
in three different symplectic frames: the SO(1,1)^{2}, SO(2,2) covariant and
SO(8)-truncated ones. The attractive nature of the critical points, related to
the semi-positive definiteness of the Hessian matrix, is also studied.


title: On the Cylindrical Grad-Shafranov Equation

abstract:
  The goal of this presentation is in paying attention to the 1D cylindrical
version of the Grad-Shafranov (GS) equation. In our opinion, this approach is
more rich than classical self-similar ones, and more suitable for astrophysical
jets we observe. In particular, it allows us describing the central (and,
hence, the most energetic) part of the flow.


title: Wave-packet Formalism of Full Counting Statistics

abstract:
  We make use of the first-quantized wave-packet formulation of the full
counting statistics to describe charge transport of noninteracting electrons in
a mesoscopic device. We derive various expressions for the characteristic
function generating the full counting statistics, accounting for both energy
and time dependence in the scattering process and including exchange effects
due to finite overlap of the incoming wave packets. We apply our results to
describe the generic statistical properties of a two-fermion scattering event
and find, among other features, sub-binomial statistics for nonentangled
incoming states (Slater rank 1), while entangled states (Slater rank 2) may
generate super-binomial (and even super-Poissonian) noise, a feature that can
be used as a spin singlet-triplet detector. Another application is concerned
with the constant-voltage case, where we generalize the original result of
Levitov-Lesovik to account for energy-dependent scattering and finite
measurement time, including short time measurements, where Pauli blocking
becomes important.


title:
Improved Constraints on the Preferential Heating and Acceleration of
  Oxygen Ions in the Extended Solar Corona

abstract:
  We present a detailed analysis of oxygen ion velocity distributions in the
extended solar corona, based on observations made with the Ultraviolet
Coronagraph Spectrometer (UVCS) on the SOHO spacecraft. Polar coronal holes at
solar minimum are known to exhibit broad line widths and unusual intensity
ratios of the O VI 1032, 1037 emission line doublet. The traditional
interpretation of these features has been that oxygen ions have a strong
temperature anisotropy, with the temperature perpendicular to the magnetic
field being much larger than the temperature parallel to the field. However,
recent work by Raouafi and Solanki suggested that it may be possible to model
the observations using an isotropic velocity distribution. In this paper we
analyze an expanded data set to show that the original interpretation of an
anisotropic distribution is the only one that is fully consistent with the
observations. It is necessary to search the full range of ion plasma parameters
to determine the values with the highest probability of agreement with the UVCS
data. The derived ion outflow speeds and perpendicular kinetic temperatures are
consistent with earlier results, and there continues to be strong evidence for
preferential ion heating and acceleration with respect to hydrogen. At
heliocentric heights above 2.1 solar radii, every UVCS data point is more
consistent with an anisotropic distribution than with an isotropic
distribution. At heights above 3 solar radii, the exact probability of isotropy
depends on the electron density chosen to simulate the line-of-sight
distribution of O VI emissivity. (abridged abstract)


title: Composite boson many-body theory for Frenkel excitons

abstract:
  We present a many-body theory for Frenkel excitons which takes into account
their composite nature exactly. Our approach is based on four commutators
similar to the ones we previously proposed for Wannier excitons. They allow us
to calculate any physical quantity dealing with $N$ excitons in terms of "Pauli
scatterings" for carrier exchange in the absence of carrier interaction and
"interaction scatterings" for carrier interaction in the absence of carrier
exchange. We show that Frenkel excitons have a novel "transfer assisted
exchange scattering", specific to these excitons. It comes from indirect
Coulomb processes between localized atomic states. These indirect processes,
commonly called "electron-hole exchange" in the case of Wannier excitons and
most often neglected, are crucial for Frenkel excitons, as they are the only
ones responsible for the excitation transfer. We also show that in spite of the
fact that Frenkel excitons are made of electrons and holes on the same atomic
site, so that we could naively see them as elementary particles, they
definitely are composite objects, their composite nature appearing through
various properties, not always easy to guess. The present many-body theory for
Frenkel excitons is thus going to appear as highly valuable to securely tackle
their many-body physics, as in the case of nonlinear optical effects in organic
semiconductors.


title:
Invariant Lagrangians, mechanical connections and the Lagrange-Poincare
  equations

abstract:
  We deal with Lagrangian systems that are invariant under the action of a
symmetry group. The mechanical connection is a principal connection that is
associated to Lagrangians which have a kinetic energy function that is defined
by a Riemannian metric. In this paper we extend this notion to arbitrary
Lagrangians. We then derive the reduced Lagrange-Poincare equations in a new
fashion and we show how solutions of the Euler-Lagrange equations can be
reconstructed with the help of the mechanical connection. Illustrative examples
confirm the theory.


title: Particle astrophysics from the cold: Results and perspectives of IceCube

abstract:
  We discuss results of the AMANDA neutrino telescope, in operation at the
South Pole since 2000, and present the status and scientific potential of its
km$^3$ extension, IceCube.


title:
Generation of Higher-Order Harmonics By Addition of a High Frequency XUV
  Radiation to the IR One

abstract:
  The irradiation of atoms by a strong IR laser field of frequency $\omega$
results in the emission of odd-harmonics of $\omega$ ("IR harmonics") up to
some maximal cut-off frequency. The addition of an XUV field of frequency
$\tilde{q}\omega$ larger than the IR cut-off frequency to the IR driver field
leads to the appearance of new higher-order harmonics ("XUV harmonics")
$\tilde{q} \pm 2K, 2\tilde{q} \pm (2K-1), 3\tilde{q} \pm 2K,...$ ($K$ integer)
which were absent in the spectra in the presence of the IR field alone. The
mechanism responsible for the appearance of the XUV harmonics is analyzed
analytically using a generalization of the semiclassical re-collision
(three-step) model of high harmonic generation. It is shown that the emitted
HHG radiation field can be written as a serie of terms, with the HHG field
obtained from the three-step model in its most familiar context [P. B. Corkum,
\textit{Phys. Rev. Lett.} {\bf 71}, 1994 (1993)] resulting from the
zeroth-order term. The origin of the higher-order terms is shown to be the
ac-Stark oscillations of the remaining ground electronic state which are
induced by the XUV field. These terms are responsible for the appearance of the
new XUV harmonics in the HGS. The XUV harmonics are formed by the same electron
trajectories which form the IR harmonics and have the same emission times, but
a much lower intensity than the IR harmonics, due to the small quiver amplitude
of the ac-Stark oscillation. Nevertheless, this mechanism allows the extension
of the cut-off in the HGS without the necessity of increasing the IR field
intensity, as is verified by numerical time-dependent Schr\"{o}dinger equation
simulation of a Xe atom shined by a combination of IR and XUV field.


title:
Spectroscopy of clusters in the ESO distant cluster survey (EDisCS).II.
  Redshifts, velocity dispersions, and substructure for clusters in the last 15
  fields

abstract:
  AIMS. We present spectroscopic observations of galaxies in 15 survey fields
as part of the ESO Distant Cluster Survey (EDisCS). We determine the redshifts
and velocity dispersions of the galaxy clusters located in these fields, and we
test for possible substructure in the clusters.
  METHODS. We obtained multi-object mask spectroscopy using the FORS2
instrument at the VLT. We reduced the data with particular attention to the sky
subtraction. We implemented the method of Kelson for performing sky subtraction
prior to any rebinning/interpolation of the data. From the measured galaxy
redshifts, we determine cluster velocity dispersions using the biweight
estimator and test for possible substructure in the clusters using the
Dressler-Shectman test.
  RESULTS. The method of subtracting the sky prior to any
rebinning/interpolation of the data delivers photon-noise-limited results,
whereas the traditional method of subtracting the sky after the data have been
rebinned/interpolated results in substantially larger noise for spectra from
tilted slits. Redshifts for individual galaxies are presented and redshifts and
velocity dispersions are presented for 21 galaxy clusters. For the 9 clusters
with at least 20 spectroscopically confirmed members, we present the
statistical significance of the presence of substructure obtained from the
Dressler-Shectman test, and substructure is detected in two of the clusters.
  CONCLUSIONS. Together with data from our previous paper, spectroscopy and
spectroscopic velocity dispersions are now available for 26 EDisCS clusters
with redshifts in the range 0.40-0.96 and velocity dispersions in the range
166-1080 km/s.


title: Paraconsistent Machines and their Relation to Quantum Computing

abstract:
  We describe a method to axiomatize computations in deterministic Turing
machines. When applied to computations in non-deterministic Turing machines,
this method may produce contradictory (and therefore trivial) theories,
considering classical logic as the underlying logic. By substituting in such
theories the underlying logic by a paraconsistent logic we define a new
computation model, the paraconsistent Turing machine. This model allows a
partial simulation of superposed states of quantum computing. Such a feature
allows the definition of paraconsistent algorithms which solve (with some
restrictions) the well-known Deutsch's and Deutsch-Jozsa problems. This first
model of computation, however, does not adequately represent the notions of
entangled states and relative phase, which are key features in quantum
computing. In this way, a more sharpened model of paraconsistent Turing
machines is defined, which better approaches quantum computing features.
Finally, we define complexity classes for such models, and establish some
relationships with classical complexity classes.


title: Boxy/peanut and discy bulges : formation, evolution and properties

abstract:
  The class `bulges' contains objects with very different formation and
evolution paths and very different properties. I review two types of `bulges',
the boxy/peanut bulges (B/Ps) and the discy bulges. The former are parts of
bars seen edge-on, have their origin in vertical instabilities of the disc and
are somewhat shorter in extent than bars. Their stellar population is similar
to that of the inner part of the disc from which they formed. Discy bulges have
a disc-like outline, i.e., seen face-on they are circular or oval and seen
edge-on they are thin. Their extent is of the order of 5 times smaller than
that of the boxy/peanut bulges. They form from the inflow of mainly gaseous
material to the centre of the galaxy and from subsequent star formation. They
thus contain a lot of young stars and gas. Bulges of different types often
coexist in the same galaxy. I review the main known results on these two types
of bulges and present new simulation results. B/Ps form about 1Gyr after the
bar, via a vertical buckling. At that time the bar strength decreases, its
inner part becomes thicker -- forming the peanut or boxy shape -- and the ratio
$\sigma_z^2/\sigma_r^2$ increases. A second buckling episode is seen in
simulations with strong bars, also accompanied by a thickening of the peanut
and a weakening of the bar. The properties of the B/Ps correlate strongly with
those of the bar: stronger bars have stronger peanuts, a more flat-topped
vertical density distribution and have experienced more bucklings. I also
present simulations of disc galaxy formation, which include the formation of a
discy bulge. Decomposition of their radial density profile into an exponential
disc and a Sersic bulge gives realistic values for the disc and bulge
scale-lengths and mass ratios, and a Sersic shape index of the order of 1.


title:
The Expansion and Radio Spectral Index of G21.5-0.9: Is PSR J1833-1034
  the Youngest Pulsar?

abstract:
  We report on new 5-GHz VLA radio observations of the pulsar-powered supernova
remnant G21.5-0.9. These observations have allowed us to make a high-quality
radio image of this remnant with a resolution of ~0.7". It has a filamentary
structure similar to that seen in the Crab Nebula. Radio structure suggestive
of the torus seen around the Crab pulsar is tentatively identified. We also
compared the new image with one taken ~15 yr earlier at 1.5 GHz, both to find
the expansion speed of the remnant and to make a spectral index image. Between
1991 and 2006, we find that the average expansion rate of the remnant is 0.11
+/- 0.02 %/year, corresponding, for a distance of 5 kpc, to a speed of 910 +/-
160 km/s wrt. the centre of the nebula. Assuming undecelerated expansion, this
expansion speed implies that the age of G21.5-0.9 is 870 (+200,-150) yr, which
makes PSR J1833-1034 one of the youngest, if not the youngest, known pulsars in
the Galaxy.


title: Generalized MSTB Models: Structure and kink varieties

abstract:
  In this paper we describe the structure of a class of two-component scalar
field models in a (1+1) Minkowskian space-time which generalize the well-known
Montonen-Sarker-Trullinger-Bishop -hence MSTB- model. This class includes all
the field models whose static field equations are equivalent to the Newton
equations of two-dimensional type I Liouville mechanical systems with a
discrete set of instability points. We offer a systematic procedure to
characterize these models and to identify the solitary wave or kink solutions
as homoclinic or heteroclinic trajectories in the analogous mechanical system.
This procedure is applied to a one-parametric family of generalized MSTB models
with a degree-eight polynomial as potential energy density.


title: The Relativistic Stern-Gerlach Force

abstract:
  The relativistic Lagrangian for a spinning particle in an electromagnetic
field is derived from the known Lagrangian in the particle's rest frame. The
resulting relativistic Stern-Gerlach and Thomas precession forces on the
particle are then derived from the Lagrangian in the laboratory frame. In
particular, the longitudinal component of this combined Stern-Gerlach-Thomas
force does not contain a term proportional to gamma-squared as was claimed in a
previous derivation [1].


title: Topics on bar and bulge formation and evolution

abstract:
  I discuss results from the COSMOS survey, showing that the fraction of disc
galaxies that is barred decreases considerably with look-back time from z ~ 0.2
to z ~ 0.8. This decrease is more important for small mass and low luminosity
spirals. Classical bar formation theory provides a promising framework for
understanding these results.
  I also discuss the formation of discy bulges using N-body simulations
reproducing well the properties of observed discy bulges. Thus, these simulated
discy bulges have the shape of a disc, they have Sersic profiles with small
values of the shape index and their size is of the order of a kpc. They are
formed by radial inflow of material driven by the bar and are thus composed of
both gas and stars and have a considerable fraction of young stars. They can
harbour spiral structure, or an inner bar.


title: Generic separable metric structures

abstract:
  We compare three notions of genericity of separable metric structures. Our
analysis provides a general model theoretic technique of showing that
structures are generic in descriptive set theoretic (topological) sense and in
measure theoretic sense.
  In particular, it gives a new perspective on Vershik's theorems on genericity
and randomness of Urysohn's space among separable metric spaces.


title:
The dynamical behaviour of homogeneous scalar-field spacetimes with
  general self-interaction potentials

abstract:
  The dynamics of homogeneous Robertson--Walker cosmological models with a
self-interacting scalar field source is examined here in full generality,
requiring only the scalar field potential to be bounded from below and
divergent when the field diverges. In this way we are able to give a unified
treatment of all the already studied cases - such as positive potentials which
exhibit asymptotically polynomial or exponential behaviors - together with its
extension to a much wider set of physically sensible potentials. Since the set
includes potentials with negative inferior bound, we are able to give, in
particular, the analysis of the asymptotically anti De Sitter states for such
cosmologies.


title: Boxy/peanut bulges : formation, evolution and properties

abstract:
  We discuss the formation and evolution of boxy/peanut bulges (B/Ps) and
present new simulations results. Orbital structure studies show that B/Ps are
parts of bars seen edge-on, they have their origin in vertical instabilities of
the disc material and they are somewhat shorter in extent than bars. When the
bar forms it is vertically thin, but after a time of the order of a Gyr it
experiences a vertical instability and buckles. At that time the strength of
the bar decreases, its inner part becomes thicker, so that, seen edge-on, it
acquires a peanut or boxy shape. A second buckling episode is seen in
simulations with strong bars, accompanied by a further thickening of the B/P
and a weakening of the bar. Quantitatively, this evolution depends considerably
on the properties of the halo and particularly on the extent of its core. This
influences the amount of angular momentum exchanged within the galaxy, emitted
by near-resonant material in the bar region and absorbed by near-resonant
material in the halo and in the outer disc. Haloes with small cores generally
harbour stronger bars and B/Ps and they often witness double buckling.


title: Cohomology and removable subsets

abstract:
  Let X be a (connected and reduced) complex space. A q-collar of X is a
bounded domain whose boundary is a union of a strongly q-pseudoconvex, a
strongly q-pseudoncave and two flat (i.e. locally zero sets of pluriharmonic
functions) hypersurfaces. Finiteness and vanishing cohomology theorems obtained
in math/0503490 and math/0701549 for semi q-coronae are generalized in this
context and lead to results on extension problem and removable sets for
sections of coherent sheaves and analytic subsets.


title:
Pressure effects on the structural and electronic properties of ABX4
  scintillating crystals

abstract:
  Studies at high pressures and temperatures are helpful for understanding the
physical properties of the solid state, including such classes of materials as,
metals, semiconductors, superconductors, or minerals. In particular, the phase
behaviour of ABX4 scintillating materials is a challenging problem with many
implications for other fields including technological applications and Earth
and planetary sciences. A great progress has been done in the last years in the
study of the pressure-effects on the structural and electronic properties of
these compounds. In particular, the high-pressure structural sequence followed
by these compounds seems now to be better understood thanks to recent
experimental and theoretical studies. Here, we will review studies on the phase
behaviour of different ABX4 scintillating materials. In particular, we will
focus on discussing the results obtained by different groups for the
scheelite-structured orthotungstates, which have been extensively studied up to
50 GPa. We will also describe different experimental techniques for obtaining
reliable data at simultaneously high pressure and high temperature. Drawbacks
and advantages of the different techniques are discussed along with recent
developments involving synchrotron x-ray diffraction, Raman scattering, and ab
initio calculations. Differences and similarities of the phase behaviour of
these materials will be discussed, on the light of the Fukunaga and Yamaoka and
the Bastide diagrams, aiming to improve the actual understanding of their
high-pressure behaviour. Possible technological and geophysical implications of
the reviewed results will be also commented.


title: Proton structure, Partons, QCD, DGLAP and beyond

abstract:
  We present an introductory discussion of deep-inelastic lepton-proton
scattering as a means to probe the substructure of the proton. A resume of QCD
is given, emphasizing the running of the coupling constant and the DGLAP
evolution equations for the parton densities. The determination of parton
distributions is discussed and their importance for predictions of processes at
the LHC is emphasized. Going beyond the pure DGLAP regime, we briefly discuss
the behaviour of parton densities at low x, and the evidence for non-linear
absorptive contributions.


title: Superpotentials and Higher Order Derivations

abstract:
  We consider algebras defined from quivers with relations that are k-th order
derivations of a superpotential, generalizing results of Dubois-Violette to the
quiver case. We give a construction compatible with Morita equivalence, and
show that many important algebras arise in this way, including McKay
correspondence algebras for GL_n for all n, and four-dimensional Sklyanin
algebras. More generally, we show that any N-Koszul, (twisted) Calabi-Yau
algebra must have a (twisted) superpotential, and construct its minimal
resolution in terms of derivations of the (twisted) superpotential. This yields
an equivalence between N-Koszul twisted Calabi-Yau algebras A and algebras
defined by a superpotential such that an associated complex is a bimodule
resolution of A. Finally, we apply these results to give a description of the
moduli space of four-dimensional Sklyanin algebras using the Weil
representation of SL_2(Z/4).


title: Connections with skew-symmetric Ricci tensor on surfaces

abstract:
  Some known results on torsionfree connections with skew-symmetric Ricci
tensor on surfaces are extended to connections with torsion, and Wong's
canonical coordinate form of such connections is simplified.


title: Spin observables and spin structure functions: inequalities and dynamics

abstract:
  Model-independent identities and inequalities relating the various spin
observables of a reaction are reviewed in a unified formalism, together with
their implications for dynamical models, their physical interpretation, and the
quantum aspects of the information carried by spins, in particular
entanglement. These constraints between observables can be obtained from the
explicit expression of the observables in terms of a set of amplitudes, a
non-trivial algebraic exercise which can be preceded by numerical simulation
with randomly chosen amplitudes, from anticommutation relations, or from the
requirement that any polarisation vector is less than unity. The most powerful
tool is the positivity of the density matrices describing the reaction or its
crossed channels, with a projection to single out correlations between two or
three observables. For the exclusive reactions, the cases of the
strangeness-exchange proton-antiproton scattering and the photoproduction of
pseudoscalar mesons are treated in some detail: all triples of observables are
constrained, and new results are presented for the allowed domains. The
positivity constraints for total cross-sections and single-particle inclusive
reactions are reviewed, with application to spin-dependent structure functions
and parton distributions. The corresponding inequalities are shown to be
preserved by the evolution equations of QCD.


title: Elliptic periods for finite fields

abstract:
  We construct two new families of basis for finite field extensions. Basis in
the first family, the so-called elliptic basis, are not quite normal basis, but
they allow very fast Frobenius exponentiation while preserving sparse
multiplication formulas. Basis in the second family, the so-called normal
elliptic basis are normal basis and allow fast (quasi linear) arithmetic. We
prove that all extensions admit models of this kind.


title: Two versions of a specific natural extension

abstract:
  We give two versions of the natural extension of a specific greedy
beta-transformation with deleted digits. We use the natural extension to obtain
an explicit expression for the invariant measure, equivalent to the Lebesgue
measure, of this beta-transformation.


title: Possible Implications of Mass Accretion in Eta Carinae

abstract:
  We apply the previously suggested accretion model for the behavior of the
super-massive binary system Eta Carinae close to periastron passages. In that
model it is assumed that for ~10 weeks near periastron passages one star is
accreting mass from the slow dense wind blown by the other star. We find that
the secondary, the less massive star, accretes ~2x10^{-6}Mo. This mass
possesses enough angular momentum to form a disk, or a belt, around the
secondary. The viscous time is too long for the establishment of equilibrium,
and the belt must be dissipated as its mass is being blown in the reestablished
secondary wind. This processes requires about half a year, which we identify
with the recovery phase of Eta Carinae. We show that radiation pressure, termed
radiative braking, cannot prevent accretion. In addition to using the commonly
assumed binary model for Eta Carinae, we also examine alternative models where
the stellar masses are larger, and/or the less massive secondary blows the slow
dense wind, while the primary blows the tenuous fast wind and accretes mass for
~10 weeks near periastron passages. We end by some predictions for the next
event (January-March 2009).


title: Electroweak double-logs at small x

abstract:
  We investigate enhanced EW corrections to inclusive hard processes in the TeV
energy region with emphasis on the small-x situation, in which the hard scale Q
is significantly smaller than the available energy \sqrt{s}= Q/x. We first
propose and justify a general factorization formula in which the (double-log)
EW form factor at scale Q^2 is factorized from EW parton distribution
functions, which satisfy evolution equations of DGLAP type. We then investigate
the small-x behavior of the EW parton distributions including the novel ones
for non-vanishing t-channel weak isospin T and we compare it with a BFKL-type
approach. In either approach we find that large small-x corrections of order
\alpha_w \log x \log Q^2/M^2 (M being the EW symmetry breaking scale) are
present only for T=2 and not for T=1. This implies that only transverse WW
interactions (coupled to T=2) are affected, while the T=1 components feel just
the form factor at scale Q^2.


title: Quantum plasma effects in the classical regime

abstract:
  For quantum effects to be significant in plasmas it is often assumed that the
temperature over density ratio must be small. In this paper we challenge this
assumption by considering the contribution to the dynamics from the electron
spin properties. As a starting point we consider a multicomponent plasma model,
where electrons with spin up and spin down are regarded as different fluids. By
studying the propagation of Alfv\'{e}n wave solitons we demonstrate that
quantum effects can survive in a relatively high-temperature plasma. The
consequences of our results are discussed.


title: New solutions to the Ginsparg-Wilson equation

abstract:
  The overlap operator is just the simplest of a class of Dirac operators with
an exact chiral symmetry. I demonstrate how a general class of chiral Dirac
operators can be constructed, show that they have no fermion doublers and that
they are all exponentially local, and test my conclusions numerically for a few
examples. However, since these operators are more expensive than the overlap
operator, it is unlikely that they will be useful in practical simulations.


title:
Dominant two-loop electroweak corrections to the hadroproduction of a
  pseudoscalar Higgs boson and its photonic decay

abstract:
  We present the dominant two-loop electroweak corrections to the partial decay
widths to gluon jets and prompt photons of the neutral CP-odd Higgs boson A^0,
with mass M_{A^0} < 2 M_W, in the two-Higgs-doublet model for low to
intermediate values of the ratio tan(beta) = v_2/v_1 of the vacuum expectation
values. They apply as they stand to the production cross sections in hadronic
and two-photon collisions, at the Tevatron, the LHC, and a future photon
collider. The appearance of three gamma_5 matrices in closed fermion loops
requires special care in the dimensional regularization of ultraviolet
divergences. The corrections are negative and amount to several percent, so
that they fully compensate or partly screen the enhancement due to QCD
corrections.


title: Generalized Fokker-Planck equation, Brownian motion, and ergodicity

abstract:
  Microscopic theory of Brownian motion of a particle of mass $M$ in a bath of
molecules of mass $m\ll M$ is considered beyond lowest order in the mass ratio
$m/M$. The corresponding Langevin equation contains nonlinear corrections to
the dissipative force, and the generalized Fokker-Planck equation involves
derivatives of order higher than two. These equations are derived from first
principles with coefficients expressed in terms of correlation functions of
microscopic force on the particle. The coefficients are evaluated explicitly
for a generalized Rayleigh model with a finite time of molecule-particle
collisions. In the limit of a low-density bath, we recover the results obtained
previously for a model with instantaneous binary collisions. In general case,
the equations contain additional corrections, quadratic in bath density,
originating from a finite collision time. These corrections survive to order
$(m/M)^2$ and are found to make the stationary distribution non-Maxwellian.
Some relevant numerical simulations are also presented.


title: On vertex algebras and their modules associated with even lattices

abstract:
  We study vertex algebras and their modules associated with possibly
degenerate even lattices, using an approach somewhat different from others.
Several known results are recovered and a number of new results are obtained.
We also study modules for Heisenberg algebras and we classify irreducible
modules satisfying certain conditions and obtain a complete reducibility
theorem.


title: Clustering Properties of Dynamical Dark Energy Models

abstract:
  We provide a generic but physically clear discussion of the clustering
properties of dark energy models. We explicitly show that in quintessence-type
models the dark energy fluctuations, on scales smaller than the Hubble radius,
are of the order of the perturbations to the Newtonian gravitational potential,
hence necessarily small on cosmological scales. Moreover, comparable
fluctuations are associated with different gauge choices. We also demonstrate
that the often used homogeneous approximation is unrealistic, and that the
so-called dark energy mutation is a trivial artifact of an effective, single
fluid description. Finally, we discuss the particular case where the dark
energy fluid is coupled to dark matter.


title:
The X-ray-Infrared/Submillimetre Connection and the Legacy Era of
  Cosmology

abstract:
  We review some recent results on the identification and characterisation of
Active Galactic Nuclei (AGN) obtained by cross correlating X-ray surveys with
infrared and submillimetre surveys. We also look toward the scientific gains
that could be achieved from an XMM-Newton survey of the medium-deep legacy
fields that are being observed at ~1-850um.


title: Relativistic Perihelion Precession of Orbits of Venus and the Earth

abstract:
  Among all the theories proposed to explain the 'anomalous' perihelion
precession of Mercury's orbit announced in 1859 by Le Verrier, the general
theory of relativity proposed by Einstein in November 1915, alone could
calculate Mercury's 'anomalous' precession with a precision demanded by
observational accuracy. Since Mercury's precession was a directly derived
result of the full general theory, it was viewed by Einstein as the most
critical test of general relativity, amongst the three tests proposed by him.
With the advent of the space age, the observational accuracy level has improved
further and it became possible to detect this precession for other planetary
orbits of the solar system -- viz., Venus and the Earth. This conclusively
proved that the phenomenon of 'anomalous' perihelion precession of planetary
orbits is really a relativistic effect. Our previous papers presented the
mathematical model and the computed value of the relativistic perihelion
precession of Mercury's orbit using an alternate relativistic gravitational
model, which is a remodeled form of Einstein's relativity theories, and which
retained only experimentally proven principles and has been enriched by the
benefits of almost a century-long relativity experimentation including the
space age experiments. Using this model, we present in this paper the computed
values of the relativistic precession of Venus and the Earth, which compare
well with the predictions of general relativity and also are in agreement with
the observed values within the range of uncertainty.


title:
Early LHC measurements to check predictions for central exclusive
  production

abstract:
  We show how the early data runs of the LHC can provide valuable checks of the
different components of the formalism used to predict the cross sections of
central exclusive processes. The `soft' rapidity gap survival factor can be
studied in electroweak processes, such as W+gaps events, where the bare
amplitude is well known. The generalized gluon distribution, in the appropriate
kinematic region, can be probed by exclusive Upsilon production. The
perturbative QCD effects, especially the Sudakov-like factor, can be probed by
exclusive two- and three-jet production. We discuss the possible role of
enhanced absorptive corrections which would violate the soft-hard factorization
implied in the usual formalism, and suggest ways that the LHC may explore their
presence.


title: The very soft X-ray spectrum of the Double Pulsar System J0737-3039

abstract:
  We present the results of an 80 ks Chandra ACIS-S observation of the double
pulsar system J0737-3039. Furthermore, we report on spectral, spatial and
timing analysis of the combined X-ray observations performed so far for this
system. Fitting a total of ~1100 photons, we show that the X-ray spectrum of
the J0737-3039 system is very soft, and not satisfactorily modeled by a simple
blackbody or an atmospheric model. However, it is not possible yet to
discriminate between a predominantly non-thermal and a predominantly thermal
origin for the X-ray emission. Adopting a simple power-law emission model, the
photon index (Gamma=3.7) and the implied conversion efficiency of the
rotational energy of PSR J0737-3039A into X-ray emission (4.1x10^-4, for a
distance to the source of 500 pc) are compatible with the X-ray photons being
emitted in the magnetosphere of PSR J0737-3039A. This hypothesis is also
supported by the absence of detectable X-ray orbital modulation (up to ~20%) or
any X-ray nebular emission and it is in agreement with the high (~75%) X-ray
pulsed fraction of PSR J0737-3039A. A two blackbody or a Comptonized blackbody
model also reproduce the data, and the upper limit to the value of the hydrogen
column density N_H <10^20 cm^-2, is in better agreement (with respect to the
power-law model) with the Galactic N_H in that direction and at that distance.
For the two blackbody model the implied emission radii and temperatures are
also compatible with those seen in other recycled pulsars, calling for the bulk
of the X-ray photons being originated from heated regions at the surface of
pulsar A. On the other hand, in the Comptonized blackbody model, the electron
temperature seems to be significantly smaller than in other similar objects.


title: On the Relation Between the Index Coding and the Network Coding Problems

abstract:
  In this paper we show that the Index Coding problem captures several
important properties of the more general Network Coding problem. An instance of
the Index Coding problem includes a server that holds a set of information
messages $X=\{x_1,...,x_k\}$ and a set of receivers $R$. Each receiver has some
side information, known to the server, represented by a subset of $X$ and
demands another subset of $X$. The server uses a noiseless communication
channel to broadcast encodings of messages in $X$ to satisfy the receivers'
demands. The goal of the server is to find an encoding scheme that requires the
minimum number of transmissions.
  We show that any instance of the Network Coding problem can be efficiently
reduced to an instance of the Index Coding problem. Our reduction shows that
several important properties of the Network Coding problem carry over to the
Index Coding problem. In particular, we prove that both scalar linear and
vector linear codes are insufficient for achieving the minimal number of
transmissions.


title: Modified Pati-Salam Model from $Z_7$ orbifolded AdS/CFT

abstract:
  We consider models built on $AdS_5\otimes S^5/\Gamma$ orbifold
compactifications of the type $IIB$ superstring, where $\Gamma$ is the abelian
group $Z_n$. An attractive three family $\mathcal{N}=0$ SUSY model is found for
$n=7$ that is a modified Pati--Salam Model which reduced to the Standard Model
after symmetry breaking.


title:
Quasi-one-dimensional disordered systems: fluctuations, transport and
  interplay

abstract:
  In a one dimensional lattice thermal fluctuations destroy the long-range
order making particles of the lattice move on a scale much larger than the
lattice spacing. We discuss the assumption that this motion may be responsible
for the transport of localized electrons in a system of weakly coupled chains.
The model with diffusing localization sites gives a temperature-independent
mobility with a crossover to an activated dependence at high temperature. This
prediction is consistent with and might account for experimental results on
discotic liquid crystals and certain biopolymers.


title: On sumfree subsets of hypercubes

abstract:
  We consider the possible sizes of large sumfree sets contained in the
discrete hypercube $\{1,...,n\}^k$, and we determine upper and lower bounds for
the maximal size as $n$ becomes large. We also discuss a continuous analogue in
which our lower bound remains valid and our upper bound can be strengthened,
and we consider the generalization of both problems to $l$-fold-sumfree sets.


title:
L^p Estimates for Maximal Averages Along One-variable Vector Fields in
  R^2

abstract:
  We prove a conjecture of Lacey and Li in the case that the vector field
depends only on one variable. Specifically: let v be a vector field defined on
the unit square such that v(x,y) = (1,u(x)) for some measurable u from [0,1] to
[0,1]. Fix a small parameter delta and let Z be the collection of rectangles R
of a fixed width such that delta much of the vector field inside R is pointed
in (approximately) the same direction as R. We show that the maximal averaging
operator associated to the collection Z is bounded on L^p for p>1 with
constants comparable to (delta)^(-1) .


title:
Classical R-Operators and Integrable Generalizations of Thirring
  Equations

abstract:
  We construct different integrable generalizations of the massive Thirring
equations corresponding loop algebras $\widetilde{\mathfrak{g}}^{\sigma}$ in
different gradings and associated ''triangular'' $R$-operators. We consider the
most interesting cases connected with the Coxeter automorphisms, second order
automorphisms and with ''Kostant-Adler-Symes'' $R$-operators. We recover a
known matrix generalization of the complex Thirring equations as a partial case
of our construction.


title: Free Groups in Lattices

abstract:
  Let G be any locally compact, unimodular, metrizable group. The main result
of this paper, roughly stated, is that if F<G is any finitely generated free
group and \Gamma < G any lattice, then up to a small perturbation and passing
to a finite index subgroup, F is a subgroup of \Gamma. If G/\Gamma is
noncompact then we require additional hypotheses that include G=SO(n,1).


title: Vortex Ferroelectric Domains

abstract:
  We show experimental switching data on microscale capacitors of
lead-zirconate-titanate (PZT), which reveal time-resolved domain behavior
during switching on a 100-ns scale. For small circular capacitors, an
unswitched domain remains in the center while complete switching is observed in
square capacitors. The observed effect is attributed to the formation of vortex
domain during polarization switching in circular capacitors. This dynamical
behavior is modeled using the Landau-Liftshitz-Gilbert equations and found to
be in detailed agreement with experiment. This simulation implies rotational
motion of polarization in the xy-plane, a Heisenberg-like result supported by
the recent model of Naumov and Fu [Phys. Rev. Lett. 98, 077603 (2007)],
although not directly measurable by the present quasi-static measurements.


title:
Occupation time fluctuation limits of infinite variance equilibrium
  branching systems

abstract:
  We establish limit theorems for the fluctuations of the rescaled occupation
time of a $(d,\alpha,\beta)$-branching particle system. It consists of
particles moving according to a symmetric $\alpha$-stable motion in
$\mathbb{R}^d$. The branching law is in the domain of attraction of a
(1+$\beta$)-stable law and the initial condition is an equilibrium random
measure for the system (defined below). In the paper we treat separately the
cases of intermediate $\alpha/\beta<d<(1+\beta)\alpha/\beta$, critical
$d=(1+\beta)\alpha/\beta$ and large $d>(1+\beta)\alpha/\beta $ dimensions. In
the most interesting case of intermediate dimensions we obtain a version of a
fractional stable motion. The long-range dependence structure of this process
is also studied. Contrary to this case, limit processes in critical and large
dimensions have independent increments.


title: Partitioning the Threads of a Mobile System

abstract:
  In this paper, we show how thread partitioning helps in proving properties of
mobile systems. Thread partitioning consists in gathering the threads of a
mobile system into several classes. The partitioning criterion is left as a
parameter of both the mobility model and the properties we are interested in.
Then, we design a polynomial time abstract interpretation-based static analysis
that counts the number of threads inside each partition class.


title: Dynamics on an infinite surface with the lattice property

abstract:
  Dynamical systems on an infinite translation surface with the lattice
property are studied. The geodesic flow on this surface is found to be
recurrent in all but countably many rational directions. Hyperbolic elements of
the affine automorphism group are found to be nonrecurrent, and a precise
formula regarding their action on cylinders is proven. A deformation of the
surface in the space of translation surfaces is found, which "behaves nicely"
with the geodesic flow and action of the affine automorphism group.


title:
Automated and robust population transfer method for three-level system
  using oscillating dark states

abstract:
  An automated and robust method for adiabatic population transfer and the
preparation of an arbitrary quantum superposition state in atomic system using
the oscillating dark states (ODS) is presented. Quantum state of a three-level
$\Lambda$ configuration atomic system oscillates periodically between two
ground levels, when two pairs of classical detuning laser fields driving the
system into the ODS under evolving adiabatic conditions. The decoherence of the
ODS evolution is greatly suppressed, and the oscillation is very stable,
therefore adiabatic population transfer and the preparation of an arbitrary
quantum superposition state of atomic system can be completed accurately and
conveniently.


title:
Covariance estimation for multivariate conditionally Gaussian dynamic
  linear models

abstract:
  In multivariate time series, the estimation of the covariance matrix of the
observation innovations plays an important role in forecasting as it enables
the computation of the standardized forecast error vectors as well as it
enables the computation of confidence bounds of the forecasts. We develop an
on-line, non-iterative Bayesian algorithm for estimation and forecasting. It is
empirically found that, for a range of simulated time series, the proposed
covariance estimator has good performance converging to the true values of the
unknown observation covariance matrix. Over a simulated time series, the new
method approximates the correct estimates, produced by a non-sequential Monte
Carlo simulation procedure, which is used here as the gold standard. The
special, but important, vector autoregressive (VAR) and time-varying VAR models
are illustrated by considering London metal exchange data consisting of spot
prices of aluminium, copper, lead and zinc.


title:
Finite rank Bergman-Toeplitz and Bargmann-Toeplitz operators in many
  dimensions

abstract:
  The recent theorem by D. Luecking that finite rank Toeplitz-Bergman operators
must be generated by a measure consisting of finitely many point masses is
carried over to the many-dimensional case.


title: First principles modeling of oxygen adsorption on LaMnO3 (001) surface

abstract:
  We present and discuss the results of ab initio DFT plane-wave supercell
calculations of the atomic and molecular oxygen adsorption and diffusion on the
LaMnO3 (001) surface which serves as a model material for a cathode of solid
oxide fuel cells. The dissociative adsorption of O2 molecules from the gas
phase is energetically favorable on surface Mn ions even on a defect-free
surface. The surface migration energy for adsorbed O ions is found to be quite
high, 1.6 eV. We predict that the adsorbed O atoms could penetrate into
electrode first plane when much more mobile surface oxygen vacancies (migration
energy of 0.69 eV) approach the O ions strongly bound to the surface Mn ions.
Ab initio thermodynamics predicts that at typical SOFC operation temperatures
(~1200 K) the MnO2 (001) surface with adsorbed O atoms is the most stable in a
very wide range of oxygen gas pressures (above 10^2 atm).


title: Enumeration of totally real number fields of bounded root discriminant

abstract:
  We enumerate all totally real number fields F with root discriminant delta_F
<= 14. There are 1229 such fields, each with degree [F:QQ] <= 9.


title: SOS model partition function and the elliptic weight functions

abstract:
  We generalize a recent observation [arXiv:math/0610433] that the partition
function of the 6-vertex model with domain-wall boundary conditions can be
obtained by computing the projections of the product of the total currents in
the quantum affine algebra $U_{q}(\hat{\mathfrak{sl}}_{2})$ in its current
realization. A generalization is proved for the the elliptic current algebra
[arXiv:q-alg/9703018,arXiv:q-alg/9601022]. The projections of the product of
total currents are calculated explicitly and are represented as integral
transforms of the product of the total currents. We prove that the kernel of
this transform is proportional to the partition function of the SOS model with
domain-wall boundary conditions.


title: Computing fundamental domains for Fuchsian groups

abstract:
  We exhibit an algorithm to compute a Dirichlet domain for a cofinite Fuchsian
group Gamma. As a consequence, we compute the invariants of Gamma, including an
explicit finite presentation for Gamma.


title:
Extended Studies of Separability Functions and Probabilities and the
  Relevance of Dyson Indices

abstract:
  We report substantial progress in the study of separability functions and
their application to the computation of separability probabilities for the
real, complex and quaternionic qubit-qubit and qubit-qutrit systems. We expand
our recent work (arXiv:0704.3723), in which the Dyson indices of random matrix
theory played an essential role, to include the use of not only the volume
element of the Hilbert-Schmidt (HS) metric, but also that of the Bures (minimal
monotone) metric as measures over these finite-dimensional quantum systems.
Further, we now employ the Euler-angle parameterization of density matrices
(rho), in addition to the Bloore parameterization. The Euler-angle separability
function for the minimally degenerate complex two-qubit states is well-fitted
by the sixth-power of the participation ratio, R(rho)=1/Tr(rho)^2.
Additionally, replacing R(rho) by a simple linear transformation of the
Verstraete-Audenaert-De Moor function (arXiv:quant-oh/0011111), we find close
adherence to Dyson-index behavior for the real and complex (nondegenerate)
two-qubit scenarios. Several of the analyses reported help to fortify our
conjectures that the HS and Bures separability probabilities of the complex
two-qubit states are 8/33 = 0.242424 and 1680 (sqrt{2}-1)/pi^8 = 0.733389,
respectively. Employing certain regularized beta functions in the role of
Euler-angle separability functions, we closely reproduce--consistently with the
Dyson-index ansatz--several HS two-qubit separability probability conjectures.


title: Merger Rates of Dark-Matter Haloes

abstract:
  We derive analytic merger rates for dark-matter haloes within the framework
of the Extended Press-Schechter (EPS) formalism. These rates become
self-consistent within EPS once we realize that the typical merger in the limit
of a small time-step involves more than two progenitors, contrary to the
assumption of binary mergers adopted in earlier studies. We present a general
method for computing merger rates that span the range of solutions permitted by
the EPS conditional mass function, and focus on a specific solution that
attempts to match the merger rates in N-body simulations. The corrected EPS
merger rates are more accurate than the earlier estimates of Lacey & Cole, by
~20% for major mergers and by up to a factor of ~3 for minor mergers of mass
ratio 1:10^4. Based on the revised merger rates, we provide a new algorithm for
constructing Monte-Carlo EPS merger trees, that could be useful in
Semi-Analytic Modeling. We provide analytic expressions and plot numerical
results for several quantities that are very useful in studies of galaxy
formation. This includes (a) the rate of mergers of a given mass ratio per
given final halo, (b) the fraction of mass added by mergers to a halo, and (c)
the rate of mergers per given main progenitor. The creation and destruction
rates of haloes serve for a self-consistency check. Our method for computing
merger rates can be applied to conditional mass functions beyond EPS, such as
those obtained by the ellipsoidal collapse model or extracted from $N$-body
simulations.


title:
Nodal quasiparticles and the onset of spin density wave order in the
  cuprates

abstract:
  We present a theory for the onset of spin density wave order in the
superconducting ground state of the cuprates. We compute the scaling dimensions
of allowed perturbations of a `relativistic' fixed point with O(4)xO(3)
symmetry, including those associated with the fermionic nodal Bogoliubov
quasiparticles. Analyses of up to six loops show that all perturbations with
square lattice symmetry are likely irrelevant. We demonstrate that the fermion
spectral functions are primarily damped by the coupling to fluctuations of a
composite field with Ising nematic order. We also discuss the influence of
quenched disorder.


title:
Collapse of magnetized hypermassive neutron stars in general relativity:
  Disk evolution and outflows

abstract:
  We study the evolution in axisymmetry of accretion disks formed
self-consistently through collapse of magnetized hypermassive neutron stars to
black holes. Such stars can arise following the merger of binary neutron stars.
They are differentially rotating, dynamically stable, and have rest masses
exceeding the mass limit for uniform rotation. However, hypermassive neutron
stars are secularly unstable to collapse due to MHD-driven angular momentum
transport. The rotating black hole which forms in this process is surrounded by
a hot, massive, magnetized torus and a magnetic field collimated along the spin
axis. This system is a candidate for the central engine of a short-hard
gamma-ray burst (GRB). Our code integrates the coupled Einstein-Maxwell-MHD
equations and is used to follow the collapse of magnetized hypermassive neutron
star models in full general relativity until the spacetime settles down to a
quasi-stationary state. We then employ the Cowling approximation, in which the
spacetime is frozen, to track the subsequent evolution of the disk. This
approximation allows us to greatly extend the disk evolutions and study the
resulting outflows, which may be relevant to the generation of a GRB. We find
that outflows are suppressed when a stiff equation of state is assumed for low
density disk material and are sensitive to the initial magnetic field
configuration.


title:
Three-dimensional simulations of rotationally-induced line variability
  from a Classical T Tauri star with a misaligned magnetic dipole

abstract:
  We present three-dimensional (3-D) simulations of rotationally induced line
variability arising from complex circumstellar environment of classical T Tauri
stars (CTTS) using the results of the 3-D magnetohydrodynamic (MHD) simulations
of Romanova et al., who considered accretion onto a CTTS with a misaligned
dipole magnetic axis with respect to the rotational axis. The density, velocity
and temperature structures of the MHD simulations are mapped on to the
radiative transfer grid, and corresponding line source function and the
observed profiles of neutral hydrogen lines (H-beta, Pa-beta and Br-gamma) are
computed using the Sobolev escape probability method. We study the dependency
of line variability on inclination angles (i) and magnetic axis misalignment
angles (Theta). By comparing our models with the Pa-beta profiles of 42 CTTS
observed by Folha & Emerson, we find that models with a smaller misaligngment
angle (Theta<~15 deg.) are more consistent with the observations which show
that majority of Pa-beta are rather symmetric around the line centre. For a
high inclination system with a small dipole misalignment angle (Theta ~ 15
deg.), only one accretion funnel (on the upper hemisphere) is visible to an
observer at any given rotational phase. This can cause an anti-correlation of
the line equivalent width in the blue wing (v<0) and that in the red wing (v>0)
over a half of a rotational period, and a positive correlation over other half.
We find a good overall agreement of the line variability behaviour predicted by
our model and those from observations. (Abridged)


title: D-terms on the resolved conifold

abstract:
  We derive a novel deformation of the warped resolved conifold background with
supersymmetry breaking ISD (1,2) fluxes by adding D7-branes to this type IIB
theory. We find spontaneous supersymmetry breaking without generating a bulk
cosmological constant. In the compactified form, our background will no longer
be a Calabi-Yau manifold as it allows a non-vanishing first Chern class. In the
presence of D7-branes the (1,2) fluxes can give rise to non-trivial D-terms. We
study the Ouyang embedding of D7-branes in detail and find that in this case
the D-terms are indeed non-zero. In the limit when we approach the singular
conifold, the D-terms vanish for Ouyang's embedding, although supersymmetry
appears to be broken.
  We also construct the F-theory lift of our background and demonstrate how
these IIB (1,2) fluxes lift to non-primitive (2,2) flux on the fourfold. The
seven branes correspond to normalisable harmonic forms. We briefly sketch a
possible way to attain an inflaton potential in this background once extra
D3-branes are introduced and point out some possibilities of restoring
supersymmetry in our background that could in principle be used as the end
point of the inflationary set-up. In a companion paper we will analyse in
details the inflationary dynamics in this background.


title: The Little Randall-Sundrum Model at the Large Hadron Collider

abstract:
  We present a predictive warped model of flavor that is cut off at an
ultraviolet scale O(10^3) TeV. This "Little Randall-Sundrum (LRS)" model is a
volume-truncation, by a factor $y \approx 6$, of the RS scenario and is
holographically dual to dynamics with number of colors larger by $y$. The LRS
couplings between Kaluza-Klein states and the Standard Model fields, including
the proton constituents, are explicitly calculable without ad hoc assumptions.
Assuming separate gauge and flavor dynamics, a number of unwanted contributions
to precision electroweak, $Z b\bar b$ and flavor observables are suppressed in
the LRS framework, compared with the corresponding RS case. An important
consequence of the LRS truncation, independent of precise details, is a
significant enhancement of the clean (golden) di-lepton LHC signals, by O(y^3),
due to a larger "$\rho$-photon" mixing and a smaller inter-composite coupling.


title:
Do Long-Lived Features Really Exist in the Solar Photosphere? II.
  Contrast of Time-Averaged Granulation Images

abstract:
  The decrease in the rms contrast of time-averaged images with the averaging
time is compared between four datasets: (1) a series of solar granulation
images recorded at La Palma in 1993; (2) a series of artificial granulation
images obtained in numerical simulations by Rieutord et al. (2002); (3) a
similar series computed by Steffen and his colleagues (see Wedemeyer et al.,
2004}); (4) a random field with some parameters typical of the granulation,
constructed by Rast (2002). In addition, (5) a sequence of images was obtained
from real granulation images using a temporal and spatial shuffling procedure,
and the contrast of the average of n images from this sequence as a function of
n is analysed. The series (1) of real granulation images exhibits a
considerably slower contrast decrease than do both the series (3) of simulated
granulation images and the series (4) of random fields. Starting from some
relatively short averaging times t, the behaviour of the contrast in series (3)
and (4) resembles the t^{-1/2} statistical law, while the shuffled series (5)
obeys the n^{-1/2} law from n = 2 on. Series (2) demonstrates a peculiarly slow
decline of contrast, which could be attributed to particular properties of the
boundary conditions used in the simulations. Comparisons between the analysed
contrast-variation laws indicate quite definitely that the brightness field of
solar granulation contains a long-lived component, which could be associated
with locally persistent dark intergranular holes and/or with the presence of
quasi-regular structures. The suggestion that the random field (4) successfully
reproduces the contrast-variation law for the real granulation (Rast, 2002) can
be declined.


title: The Chern coefficients of local rings

abstract:
  The Chern numbers of the title are the first coefficients (after the
multiplicities) of the Hilbert functions of various filtrations of ideals of a
local ring $(R, \mathfrak{m})$. For a Noetherian (good) filtration
$\mathcal{A}$ of $\mathfrak{m}$-primary ideals, the positivity and bounds for
$e_1(\mathcal{A})$ are well-studied if $R$ is Cohen-Macaulay, or more broadly,
if $R$ is a Buchsbaum ring or mild generalizations thereof.
  For arbitrary geometric local domains, we introduce techniques based on the
theory of maximal Cohen-Macaulay modules and of extended multiplicity functions
to establish the meaning of the positivity of $e_1(\mathcal{A})$, and to derive
lower and upper bounds for $e_1(\mathcal{A})$.


title:
The Infrared Detection of the Pulsar Wind Nebula in the Galactic
  Supernova Remnant 3C 58

abstract:
  We present infrared observations of 3C 58 with the Spitzer Space Telescope
and the Canada-France-Hawaii Telescope. Using the IRAC camera, we have imaged
the entire source resulting in clear detections of the nebula at 3.6 and 4.5
microns. The derived flux values are consistent with extrapolation of the X-ray
spectrum to the infrared band, demonstrating that any cooling break in the
synchrotron spectrum must occur near the soft X-ray band. We also detect the
torus surrounding PSR J0205+6449, the 65 ms pulsar that powers 3C 58. The torus
spectrum requires a break between the infrared and X-ray bands, and perhaps
multiple breaks. This complex spectrum, which is an imprint of the particles
injected into the nebula, has considerable consequences for the evolution of
the broadband spectrum of 3C 58. We illustrate these effects and discuss the
impact of these observations on the modeling of broadband spectra of pulsar
wind nebulae.


title: The First Stars

abstract:
  The formation of the first generations of stars at redshifts z > 15-20
signaled the transition from the simple initial state of the universe to one of
increasing complexity. We here review recent progress in understanding the
assembly process of the first galaxies, starting with cosmological initial
conditions and modelling the detailed physics of star formation. In particular,
we study the role of HD cooling in ionized primordial gas, the impact of UV
radiation produced by the first stars, and the propagation of the supernova
blast waves triggered at the end of their brief lives. We conclude by
discussing how the chemical abundance patterns observed in extremely
low-metallicity stars allow us to probe the properties of the first stars.


title: Limits of Solutions to a Parabolic Monge-Ampere Equation

abstract:
  We present the results from our earlier paper (arXiv:math/0602484) on the
affine normal flow on noncompact convex hypersurfaces in affine space from a
more PDE point of view, emphasizing the estimates involved. Our results concern
the limits of solutions to a parabolic Monge-Ampere equation on $S^n$, where a
sequence of smooth strictly convex initial value functions increase
monotonically to a limiting initial value function which is infinite on at
least a hemisphere of $S^n$. We prove long-time existence and instantaneous
smoothing for quite general initial data, and we characterize ancient solutions
as ellipsoids or paraboloids. We make essential use of estimates of Andrews and
Gutierrez-Huang, and barriers due to Calabi.


title:
Reliable protein folding on non-funneled energy landscapes: the free
  energy reaction path

abstract:
  A theoretical framework is developed to study the dynamics of protein
folding. The key insight is that the search for the native protein conformation
is influenced by the rate r at which external parameters, such as temperature,
chemical denaturant or pH, are adjusted to induce folding. A theory based on
this insight predicts that (1) proteins with non-funneled energy landscapes can
fold reliably to their native state, (2) reliable folding can occur as an
equilibrium or out-of-equilibrium process, and (3) reliable folding only occurs
when the rate r is below a limiting value, which can be calculated from
measurements of the free energy. We test these predictions against numerical
simulations of model proteins with a single energy scale.


title:
Equal- and unequal-mass mergers of disk and elliptical galaxies with
  black holes

abstract:
  We present binary galaxy merger simulations with varying mass ratios and
different progenitor morphologies. The simulations include mergers of gas-rich
disks (Sp-Sp), of early-type galaxies and disks (E-Sp, mixed mergers), and
mergers of early-type galaxies (E-E, dry mergers). We follow the dynamics of
gas, stars and dark matter, and include radiative cooling, star formation and
black hole (BH) accretion. For Sp-Sp mergers, the peak star formation rate and
BH accretion rate decrease and the growth timescales of the central black holes
and newly formed stars increase with higher progenitor mass ratios. The peak BH
accretion rate typically occurs shortly after the time of BH merging for low
progenitor mass ratios (e.g. 3:1 and lower), whereas for higher progenitor mass
ratios there is no clear correlation between the peak BH accretion rate and BH
merging time. The termination of star formation by BH feedback in disk mergers
is significantly less important for higher progenitor mass ratios (e.g. 3:1 and
higher). In addition, the inclusion of BH feedback suppresses efficiently star
formation in dry E-E mergers and mixed E-Sp mergers. All merger remnants,
independent of their progenitors, follow the observed relations between the
central BH mass and the stellar velocity dispersion M_BH-sigma, the bulge mass
M_BH-M_* and the bulge binding energy M_BH-M_{*}sigma^2, with the dominant
source of scatter arising from variations in the initial gas mass fraction. The
normalizations for all relations and the simulated slope of the M_BH-sigma and
M_BH-M_{*}sigma^2 relations are in good agreement with the observations,
whereas the simulated slope of the M_BH-M_* relation is slightly steeper
compared to the observations. (abridged)


title: On noetherianity for logical formulas over fields

abstract:
  In this paper we consider noetherianity for formulas of propositional and
predicate calculus over different fields. Three types of noetherianity are
considered: standard noetherianity, logical noetherianity and denumerable
noetherianity.


title:
A topological formal treatment for scenario-based software specification
  of concurrent real-time systems

abstract:
  Real-time systems are computing systems in which the meeting of their
requirements is vital for their correctness. Consequently, if the real-time
requirements of these systems are poorly understood and verified, the results
can be disastrous and lead to irremediable project failures at the early phases
of development. The present work addresses the problem of detecting deadlock
situations early in the requirements specification phase of a concurrent real
time system, proposing a simple proof-of-concepts prototype that joins
scenario-based requirements specifications and techniques based on topology.
The efforts are concentrated in the integration of the formal representation of
Message Sequence Chart scenarios into the deadlock detection algorithm of
Fajstrup et al., based on geometric and algebraic topology.


title:
Posterior mean and variance approximation for regression and time series
  problems

abstract:
  This paper develops a methodology for approximating the posterior first two
moments of the posterior distribution in Bayesian inference. Partially
specified probability models, which are defined only by specifying means and
variances, are constructed based upon second-order conditional independence, in
order to facilitate posterior updating and prediction of required
distributional quantities. Such models are formulated particularly for
multivariate regression and time series analysis with unknown observational
variance-covariance components. The similarities and differences of these
models with the Bayes linear approach are established. Several subclasses of
important models, including regression and time series models with errors
following multivariate $t$, inverted multivariate $t$ and Wishart
distributions, are discussed in detail. Two numerical examples consisting of
simulated data and of US investment and change in inventory data illustrate the
proposed methodology.


title: Multivariate stochastic volatility with Bayesian dynamic linear models

abstract:
  This paper develops a Bayesian procedure for estimation and forecasting of
the volatility of multivariate time series. The foundation of this work is the
matrix-variate dynamic linear model, for the volatility of which we adopt a
multiplicative stochastic evolution, using Wishart and singular multivariate
beta distributions. A diagonal matrix of discount factors is employed in order
to discount the variances element by element and therefore allowing a flexible
and pragmatic variance modelling approach. Diagnostic tests and sequential
model monitoring are discussed in some detail. The proposed estimation theory
is applied to a four-dimensional time series, comprising spot prices of
aluminium, copper, lead and zinc of the London metal exchange. The empirical
findings suggest that the proposed Bayesian procedure can be effectively
applied to financial data, overcoming many of the disadvantages of existing
volatility models.


title: Real mixed Hodge structures

abstract:
  We identify the category of real mixed Hodge structures with the category of
vector bundles with connections (not necessarily flat) on C, equivariant with
respect to C^*. Here C is the complex plane considered as a 2-dimensional real
manifold, and C^* is the multiplicative group of complex numbers considered as
a real group.


title: On the Impossibility of a Poincare-invariant Vacuum State with Unit Norm

abstract:
  In the standard construction of Quantum Field Theory, a vacuum state is
required. The vacuum is a vector in a separable, infinite-dimensional Hilbert
space often referred to as Fock space. By definition the vacuum wavestate
depends on nothing and must be translationally invariant. We show that any such
translationally-invariant vector must have a norm that is either divergent or
equal to zero. It is impossible for any state to be both everywhere
translationally invariant and also have a norm of one. The axioms of QFT cannot
be made internally consistent.


title: Aspects of Hadron Physics

abstract:
  Detailed investigations of the structure of hadrons are essential for
understanding how matter is constructed from the quarks and gluons of Quantum
chromodynamics (QCD), and amongst the questions posed to modern hadron physics,
three stand out. What is the rigorous, quantitative mechanism responsible for
confinement? What is the connection between confinement and dynamical chiral
symmetry breaking? And are these phenomena together sufficient to explain the
origin of more than 98% of the mass of the observable universe? Such questions
may only be answered using the full machinery of nonperturbative relativistic
quantum field theory. This contribution provides a perspective on progress
toward answering these key questions. In so doing it will provide an overview
of the contemporary application of Dyson-Schwinger equations in Hadron Physics.
The presentation assumes that the reader is familiar with the concepts and
notation of relativistic quantum mechanics, with the functional integral
formulation of quantum field theory and with regularisation and renormalisation
in its perturbative formulation.


title: Multivariate control charts based on Bayesian state space models

abstract:
  This paper develops a new multivariate control charting method for vector
autocorrelated and serially correlated processes. The main idea is to propose a
Bayesian multivariate local level model, which is a generalization of the
Shewhart-Deming model for autocorrelated processes, in order to provide the
predictive error distribution of the process and then to apply a univariate
modified EWMA control chart to the logarithm of the Bayes' factors of the
predictive error density versus the target error density. The resulting chart
is proposed as capable to deal with both the non-normality and the
autocorrelation structure of the log Bayes' factors. The new control charting
scheme is general in application and it has the advantage to control
simultaneously not only the process mean vector and the dispersion covariance
matrix, but also the entire target distribution of the process. Two examples of
London metal exchange data and of production time series data illustrate the
capabilities of the new control chart.


title:
Dynamic generalized linear models for non-Gaussian time series
  forecasting

abstract:
  The purpose of this paper is to provide a discussion, with illustrating
examples, on Bayesian forecasting for dynamic generalized linear models
(DGLMs). Adopting approximate Bayesian analysis, based on conjugate forms and
on Bayes linear estimation, we describe the theoretical framework and then we
provide detailed examples of response distributions, including binomial,
Poisson, negative binomial, geometric, normal, log-normal, gamma, exponential,
Weibull, Pareto, beta, and inverse Gaussian. We give numerical illustrations
for all distributions (except for the normal). Putting together all the above
distributions, we give a unified Bayesian approach to non-Gaussian time series
analysis, with applications from finance and medicine to biology and the
behavioural sciences. Throughout the models we discuss Bayesian forecasting
and, for each model, we derive the multi-step forecast mean. Finally, we
describe model assessment using the likelihood function, and Bayesian model
monitoring.


title: Forecasting with time-varying vector autoregressive models

abstract:
  The purpose of this paper is to propose a time-varying vector autoregressive
model (TV-VAR) for forecasting multivariate time series. The model is casted
into a state-space form that allows flexible description and analysis. The
volatility covariance matrix of the time series is modelled via inverted
Wishart and singular multivariate beta distributions allowing a fully conjugate
Bayesian inference. Model performance and model comparison is done via the
likelihood function, sequential Bayes factors, the mean of squared standardized
forecast errors, the mean of absolute forecast errors (known also as mean
absolute deviation), and the mean forecast error. Bayes factors are also used
in order to choose the autoregressive order of the model. Multi-step
forecasting is discussed in detail and a flexible formula is proposed to
approximate the forecast function. Two examples, consisting of bivariate data
of IBM shares and of foreign exchange (FX) rates for 8 currencies, illustrate
the methods. For the IBM data we discuss model performance and multi-step
forecasting in some detail. For the FX data we discuss sequential portfolio
allocation; for both data sets our empirical findings suggest that the TV-VAR
models outperform the widely used VAR models.