title:
Perturbative Theory of Grazing-Incidence Diffuse Nuclear Resonant
  Scattering of Synchrotron Radiation

abstract:
  Theoretical description of off-specular grazing-incidence nuclear resonant
scattering of synchrotron radiation (Synchrotron M\"{o}ssbauer Reflectometry,
SMR) is presented. The recently developed SMR, similarly to polarized neutron
reflectometry (PNR), is an analytical tool for the determination of isotopic
and magnetic structure of thin films and multilayers. It combines the
sensitivity of M\"{o}ssbauer spectroscopy to hyperfine interactions and the
depth selectivity of x-ray reflectometry. Specular reflection provides
information on the depth profile, while off-specular scattering on the lateral
structure of scattering layers. Off-specular SMR and PNR intensity formulae of
a rather general multilayer with different domains, based on a Distorted
Incident-Wave Approximation (DIWA) are presented. The Distorted-Wave Born
Approximation (DWBA) results are given in an Appendix. Physical and numerical
implications, why using DIWA, are explained. The temporal character of SMR
imposes specific differences between SMR and PNR. In order to reveal the limits
of DIWA and to compare the two analytical methods, two-dimensional diffuse SMR
and PNR maps of an antiferromagnetic multilayer are calculated and critically
compared. Experimental '$\omega-2\theta$' SMR map of a periodic $[
\mathrm{Fe}/\mathrm{Cr}]_{20}$ multilayer is presented and compared with
simulations by the present theory.


title: Subcritical Lp bounds on spectral clusters for Lipschitz metrics

abstract:
  We establish asymptotic bounds on the L^p norms of spectrally localized
functions in the case of two-dimensional Dirichlet forms with coefficients of
Lipschitz regularity. These bounds are new for the range p>6. A key step in the
proof is bounding the rate at which energy spreads for solutions to hyperbolic
equations with Lipschitz coefficients.


title: Fractional Hamiltonian Monodromy from a Gauss-Manin Monodromy

abstract:
  Fractional Hamiltonian Monodromy is a generalization of the notion of
Hamiltonian Monodromy, recently introduced by N. N. Nekhoroshev, D. A.
Sadovskii and B. I. Zhilinskii for energy-momentum maps whose image has a
particular type of non-isolated singularities. In this paper, we analyze the
notion of Fractional Hamiltonian Monodromy in terms of the Gauss-Manin
Monodromy of a Riemann surface constructed from the energy-momentum map and
associated to a loop in complex space which bypasses the line of singularities.
We also prove some propositions on Fractional Hamiltonian Monodromy for 1:-n
and m:-n resonant systems.


title: The wave equation on Schwarzschild-de Sitter spacetimes

abstract:
  We consider solutions to the linear wave equation $\Box_g\phi=0$ on a
non-extremal maximally extended Schwarzschild-de Sitter spacetime arising from
arbitrary smooth initial data prescribed on an arbitrary Cauchy hypersurface.
(In particular, no symmetry is assumed on initial data, and the support of the
solutions may contain the sphere of bifurcation of the black/white hole
horizons and the cosmological horizons.) We prove that in the region bounded by
a set of black/white hole horizons and cosmological horizons, solutions $\phi$
converge pointwise to a constant faster than any given polynomial rate, where
the decay is measured with respect to natural future-directed advanced and
retarded time coordinates. We also give such uniform decay bounds for the
energy associated to the Killing field as well as for the energy measured by
local observers crossing the event horizon. The results in particular include
decay rates along the horizons themselves. Finally, we discuss the relation of
these results to previous heuristic analysis of Price and Brady et al.


title: Approximate Model of Neutron Resonant Scattering in a Crystal

abstract:
  In the theory of resonant scattering, the double differential cross section
involves the computation of a multifold integral of a 4-point correlation
function, which generalizes the traditional 2-point correlation function of
Van-Hove for potential scattering. In the case of a neutron-crystal
interaction, the numerical computation of these multifold integrals is
cumbersome. In this paper, a new approximation is suggested. It is based on a
factorization of the differential cross section into one function describing
the exchange of kinetic energy between the neutron and the bound nucleus
(phonons dynamic) and a function related to the nuclear scattering amplitude.
This formalism is then applied to the modeling of resonant scattering of a
neutron by $^{238}U$ in a $UO_2$ crystal lattice.


title: Shape and orientation of stellar velocity ellipsoids in spiral galaxies

abstract:
  We present a numerical study of the properties of the stellar velocity
distribution in stellar discs which have developed a saturated, two-armed
spiral structure. We follow the growth of the spiral structure deeply into the
non-linear regime by solving the Boltzmann moment equations up to second order.
By adopting the thin-disc approximation, we restrict our study of the stellar
velocity distribution to the plane of the stellar disc. We find that the outer
(convex) edges of stellar spiral arms are characterized by peculiar properties
of the stellar velocity ellipsoids, which make them distinct from most other
galactic regions. In particular, the ratio \sigma_1:\sigma_2 of the smallest
versus largest principal axes of the stellar velocity ellipsoid can become
abnormally small (as compared to the rest of the disc) near the outer edges of
spiral arms. Moreover, the epicycle approximation fails to reproduce the ratio
of the tangential versus radial velocity dispersions in these regions. These
peculiar properties of the stellar velocity distribution are caused by
large-scale non-circular motions of stars, which in turn are triggered by the
non-axisymmetric gravitational field of stellar spiral arms. The magnitude of
the vertex deviation appears to correlate globally with the amplitude of the
spiral stellar density perturbations. However, locally there is no simple
correlation between the vertex deviation and the density perturbations.
(Abstract abridged).


title:
Time-Dependent {\boldmath $CP$}-Violating Asymmetry in
  $B^0\to\rho^0\gamma$ Decays

abstract:
  We report the first measurement of CP-violation parameters in
  $B^0\to\rho^0\gamma$ decays based on a data sample of $657\times 10^6
B\bar{B}$ pairs collected with the Belle detector at the KEKB asymmetric-energy
$e^+ e^-$ collider. The flavor of the $B$ meson is identified from the decay
products of the accompanying $B$ meson. We obtain the time-dependent and direct
CP-violating parameters, $\cals_{\rhoz\gamma} = -0.83\pm 0.65(stat)\pm
0.18(syst)$ and $\cala_{\rhoz\gamma} = -0.44\pm 0.49(stat)\pm 0.14(syst)$,
respectively.


title:
Renormalization of chiral two-pion exchange NN interactions. Momentum
  vs. coordinate space

abstract:
  The renormalization of the chiral np interaction in the 1S0 channel to N3LO
in Weinberg counting for the long distance potential with one single momentum
and energy independent counterterm is carried out. This renormalization scheme
yields finite and unique results and is free of short distance off-shell
ambiguities. We observe good convergence in the entire elastic range below pion
production threshold and find that there are some small physical effects
missing in the purely pionic chiral NN potential with or without inclusion of
explicit Delta degrees of freedom. We also study the renormalizability of the
standard Weinberg counting at NLO and N2LO when a momentum dependent polynomial
counterterm is included. Our numerical results suggest that the inclusion of
this counterterm does not yield a convergent amplitude (at NLO and N2LO).


title: Interacting Brownian motions and the Gross-Pitaevskii formula

abstract:
  We review probabilistic approaches to the Gross-Pitaevskii theory describing
interacting dilute systems of particles. The main achievement are large
deviations principles for the mean occupation measure of a large system of
interacting Brownian motions in a trapping potential. The corresponding rate
functions are given as variational problems whose solution provide effective
descriptions of the infinite system.


title: Modelling discontinuities and Kelvin-Helmholtz instabilities in SPH

abstract:
  In this paper we discuss the treatment of discontinuities in Smoothed
Particle Hydrodynamics (SPH) simulations. In particular we discuss the
difference between integral and differential representations of the fluid
equations in an SPH context and how this relates to the formulation of dissip
ative terms for the capture of shocks and other discontinuities.
  This has important implications for many problems, in particular related to
recently highlighted problems in treating Kelvin-Helmholtz instabilities across
entropy gradients in SPH. The specific problems pointed out by Agertz et al.
(2007) are shown to be related in particular to the (lack of) treatment of
contact discontinuities in standard SPH formulations which can be cured by the
simple application of an artificial thermal conductivity term. We propose a new
formulation of artificial thermal conductivity in SPH which minimises
dissipation away from discontinuities and can therefore be applied quite
generally in SPH calculations.


title: Applications of dimensional reduction to electroweak and QCD matter

abstract:
  This paper is a slightly modified version of the introductory part of a
doctoral dissertation also containing the articles hep-ph/0311268,
hep-ph/0510375, hep-ph/0512177 and hep-ph/0701250. The thesis discusses
effective field theory methods, in particular dimensional reduction, in the
context of finite temperature field theory. We first briefly review the
formalism of thermal field theory and show how dimensional reduction emerges as
the high-temperature limit for static quantities. Then we apply dimensional
reduction to two distinct problems, the pressure of electroweak theory and the
screening masses of mesonic operators in hot QCD, and point out the
similarities. We summarize the results and discuss their validity, while
leaving all details to original research articles.


title:
Intense terahertz laser fields on a two-dimensional hole gas with Rashba
  spin-orbit coupling

abstract:
  We investigate the influence on the density of states and the density of spin
polarization for a two-dimensional hole gas with Rashba spin-orbit coupling
under intense terahertz laser fields. Via Floquet theorem, we solve the
time-dependent Schr\"{o}dinger equation and calculate these densities. It is
shown that a terahertz magnetic moment can be induced for low hole
concentration. Different from the electron case, the induced magnetic moment is
quite anisotropic due to the anisotropic spin-orbit coupling. Both the
amplitude and the direction of the magnetic moment depend on the direction of
the terahertz field. We further point out that for high hole concentration, the
magnetic moment becomes very small due to the interference caused by the
momentum dependence of the spin-orbit coupling. This effect also appears in
two-dimensional electron systems.


title: How often does the ratchet click? Facts, heuristics, asymptotics

abstract:
  The evolutionary force of recombination is lacking in asexually reproducing
populations. As a consequence, the population can suffer an irreversible
accumulation of deleterious mutations, a phenomenon known as Muller's ratchet.
We formulate discrete and continuous time versions of Muller's ratchet.
Inspired by Haigh's (1978) analysis of a dynamical system which arises in the
limit of large populations, we identify the parameter gamma =
N*lambda/(Ns*log(N*lambda)) as most important for the speed of accumulation of
deleterious mutations. Here N is population size, s is the selection
coefficient and lambda is the deleterious mutation rate. For large parts of the
parameter range, measuring time in units of size N, deleterious mutations
accumulate according to a power law in N*lambda with exponent gamma if
gamma>0.5. For gamma<0.5 mutations cannot accumulate. We obtain diffusion
approximations for three different parameter regimes, depending on the speed of
the ratchet. Our approximations shed new light on analyses of Stephan et al.
(1993) and Gordo & Charlesworth (2000). The heuristics leading to the
approximations are supported by simulations.


title: A note on calculating autocovariances of periodic ARMA models

abstract:
  An analytically simple and tractable formula for the start-up autocovariances
of periodic ARMA (PARMA) models is provided.


title: Basic outlines of a new hypothesis on physical reality

abstract:
  The papers mentioned in the bibliography lead to this new hypothesis which
constitutes a wide panorama of the physical reality. Its coherence and its
simplicity are virtues that make interesant to gaze upon it.


title:
A search for Very High Energy gamma-ray emission from Passive
  Super-massive Black Holes

abstract:
  Jets of Active Galactic Nuclei (AGN) are established emitters of very high
energy (VHE; >100 GeV) gamma-rays. VHE radiation is also expected to be emitted
from the vicinity of super-massive black holes (SMBH), irrespective of their
activity state. Accreting SMBH rotate and generate a dipolar magnetic field. In
the magnetosphere of the spinning black hole, acceleration of particles can
take place in the field gaps. VHE emission from these particles is feasible via
leptonic or hadronic processes. Therefore quiescent systems, where the lack of
a strong photon field allows the VHE emission to escape, are candidates for
emission. The H.E.S.S. experiment has observed the passive SMBH in the nearby
galaxy NGC 1399. No VHE gamma-ray signal is observed from the galactic nucleus.
Constraints set by the NGC 1399 observations are discussed in the context of
different mechanisms for the production of VHE gamma-ray emission.


title:
Full counting statistics of spin transfer through ultrasmall quantum
  dots

abstract:
  We analyze the spin-resolved full counting statistics of electron transfer
through an ultrasmall quantum dot coupled to metallic electrodes. Modelling the
setup by the Anderson Hamiltonian, we explicitly take into account the onsite
Coulomb repulsion $U$. We calculate the cumulant generating function for the
probability to transfer a certain number of electrons with a preselected spin
orientation during a fixed time interval. With the cumulant generating function
at hand we are then able to calculate the spin current correlations which are
of outmost importance in the emerging field of spintronics. We confirm the
existing results for the charge statistics and report the discovery of the new
type of correlation between the spin-up and -down polarized electrons flows,
which has a potential to become a powerful new instrument for the investigation
of the Kondo effect in nanostructures.


title:
The stellar content of low redshift BL Lac host galaxies from
  multicolour imaging

abstract:
  We present B-band imaging of 18 low redshift (z<0.3) BL Lac objects for which
their host galaxies were previously resolved in the R-band and the
near-infrared H-band. For a subset of the objects, also U- and V-band imaging
is presented. These data are used to investigate the blue-red-near-infrared
colours and the colour gradients of the host galaxies of BL Lacs in comparison
with other elliptical galaxies with and without nuclear activity. In all cases
galaxies are well represented by an elliptical model, with average absolute
magnitude M_B=-21.6+-0.7 and average scale length R_e=7.6+-3.2 kpc. The
best-fit B-band Kormendy relation is in reasonable agreement with that obtained
for normal ellipticals and radio galaxies. This structural and dynamical
similarity indicates that all massive elliptical galaxies can experience
nuclear activity without significant perturbation of their global structure.
The distributions of the integrated blue/near-infrared colour (with average
B-H=3.5+-0.5) and colour gradient (with average Delta(B-R)/Delta(log
r)=-0.14+-0.75) of the BL Lac hosts are much wider than those for normal
ellipticals, and most BL Lac objects have bluer hosts and/or steeper colour
gradients than those in normal ellipticals. The blue colours are likely caused
by a young stellar population component, and indicates a link between star
formation caused by an interaction/merging event and the onset of the nuclear
activity. This result is corroborated by stellar population modelling,
indicating a presence of young/intermediate age populations in the majority of
the sample, in agreement with low redshift quasar hosts. The lack of strong
signs of interaction may require a significant time delay between the event
with associated star formation episodes and the start of the nuclear activity.


title:
Volume-energy correlations in the slow degrees of freedom of
  computer-simulated phospholipid membranes

abstract:
  Constant-pressure molecular-dynamics simulations of phospholipid membranes in
the fluid phase reveal strong correlations between equilibrium fluctuations of
volume and energy on the nanosecond time-scale. The existence of strong
volume-energy correlations was previously deduced indirectly by Heimburg from
experiments focusing on the phase transition between the fluid and the ordered
gel phases. The correlations, which are reported here for three different
membranes (DMPC, DMPS-Na, and DMPSH), have volume-energy correlation
coefficients ranging from 0.81 to 0.89. The DMPC membrane was studied at two
temperatures showing that the correlation coefficient increases as the phase
transition is approached.


title:
Ab initio and Molecular Dynamics Study of the Nanomechanical Properties
  of DNA Oligomers

abstract:
  Although a vast amount of experimental information is available on the
elongation, compression, and folding of proteins in biochemical processes, very
little is known about the real structure and molecular dynamics of DNA at an
atomic level. Since this area of work is relatively new, this paper reports the
results of computer simulation of elongation and compression of B-DNA
structures providing new insights into high- energy forms of DNA implicated in
these processes.


title:
Three-dimensional aspects of fluid flows in channels. I. Meniscus and
  Thin Film regimes

abstract:
  We study the forced displacement of a fluid-fluid interface in a
three-dimensional channel formed by two parallel solid plates. Using a
Lattice-Boltzmann method, we study situations in which a slip velocity arises
from diffusion effects near the contact line. The difference between the slip
and channel velocities determines whether the interface advances as a meniscus
or a thin film of fluid is left adhered to the plates. We find that this effect
is controlled by the capillary and Peclet numbers. We estimate the crossover
from a meniscus to a thin film and find good agreement with numerical results.
The penetration regime is examined in the steady state. We find that the
occupation fraction of the advancing finger relative to the channel thickness
is controlled by the capillary number and the viscosity contrast between the
fluids. For high viscosity contrast, Lattice-Boltzmann results agree with
previous results. For zero viscosity contrast, we observe remarkably narrow
fingers. The shape of the finger is found to be universal.


title: Putting a cap on causality violations in CDT

abstract:
  The formalism of causal dynamical triangulations (CDT) provides us with a
non-perturbatively defined model of quantum gravity, where the sum over
histories includes only causal space-time histories. Path integrals of CDT and
their continuum limits have been studied in two, three and four dimensions.
Here we investigate a generalization of the two-dimensional CDT model, where
the causality constraint is partially lifted by introducing weighted branching
points, and demonstrate that the system can be solved analytically in the
genus-zero sector.


title:
Three-dimensional aspects of fluid flows in channels. II. Effects of
  Meniscus and Thin Film regimes on Viscous Fingers

abstract:
  We perform a three-dimensional study of steady state viscous fingers that
develop in linear channels. By means of a three-dimensional Lattice-Boltzmann
scheme that mimics the full macroscopic equations of motion of the fluid
momentum and order parameter, we study the effect of the thickness of the
channel in two cases. First, for total displacement of the fluids in the
channel thickness direction, we find that the steady state finger is
effectively two-dimensional and that previous two-dimensional results can be
recovered by taking into account the effect of a curved meniscus across the
channel thickness as a contribution to surface stresses. Secondly, when a thin
film develops in the channel thickness direction, the finger narrows with
increasing channel aspect ratio in agreement with experimental results. The
effect of the thin film renders the problem three-dimensional and results
deviate from the two-dimensional prediction.


title: Existence of Unexcited and Excited Biexcitons in Molecular Crystals

abstract:
  The theory of four-body systems is revisited. It is illustrated that the
theory provides a rigorous proof for the formation of ground state (unexcited)
biexcitons in molecular crystals. The generalization of the theory predicts the
possible existence of excited biexcitons in nature. In order to test the
validity of the extended theory on computational level, a very elaborate
computer code is constructed for the treatment of arbitrary four-body system
with arbitrary electron/hole mass ratio and arbitrary exciton - exciton
interaction (VXX). The results, for mass ratio = 1 and VXX is a pure Coulomb
force, show that the test is successful. Realization of these conclusions on
experimental level should open the door for wide industrial applications.


title:
Quantum Transport in Metalporphyrins. An ab initio Green's function
  approach to nanosensors design

abstract:
  An ab initio Green's function study of the electron transport properties of
the selected metal-porphyrin complexes has been performed. Transmission spectra
and current-voltage dependence have been calculated for the porphyrin molecule
located between gold electrodes in the presence of interaction with metal
atoms, which are most common in biochemistry (Fe(II), Fe(III), Mn(II), and
Zn(II)). It was shown that the estimated Fermi level almost coincides with the
LUMO level of Fe(II)-porphyrin and Fe(III)-porphyrin, resulting in significant
conductance at small voltage biases. Conductance of Mn(II)-porphyrin and
Zn(II)-porphyrin are much lower, and decrease from Mn to Zn. It was confirmed
that performing spin-unrestricted calculations is essential to account
splitting of the original molecular orbitals levels. Preformed calculations
demonstrate the principal possibility of experimental realization of porphyrin
based nanosensors.


title: Laser control in a bifurcating region

abstract:
  We present a complete analysis of the laser control of a model molecular
system using both optimal control theory and adiabatic techniques. This
molecule has a particular potential energy surface with a bifurcating region
connecting three potential wells which allows a variety of processes such as
isomerization, tunnelling or implementation of quantum gates on one or two
qubits. The parameters of the model have been chosen so as to reproduce the
main features of H3CO which is a molecule-benchmark for such dynamics. We show
the feasibility of different processes and we investigate their robustness
against variations of laser field. We discuss the conditions under which each
method of control gives the best results. We also point out the relation
between optimal control theory and local control.


title:
PT-symmetric Solutions of Schrodinger Equation with position-dependent
  mass via Point Canonical Transformation

abstract:
  PT-symmetric solutions of Schrodinger equation are obtained for the Scarf and
generalized harmonic oscillator potentials with the position-dependent mass. A
general point canonical transformation is applied by using a free parameter.
Three different forms of mass distributions are used. A set of the energy
eigenvalues of the bound states and corresponding wave functions for target
potentials are obtained as a function of the free parameter.


title: A Quantum Dot with Impurity in the Lobachevsky Plane

abstract:
  The curvature effect on a quantum dot with impurity is investigated. The
model is considered on the Lobachevsky plane. The confinement and impurity
potentials are chosen so that the model is explicitly solvable. The Green
function as well as the Krein Q-function are computed.


title: Kalman Filtering with Equality and Inequality State Constraints

abstract:
  Both constrained and unconstrained optimization problems regularly appear in
recursive tracking problems engineers currently address -- however, constraints
are rarely exploited for these applications. We define the Kalman Filter and
discuss two different approaches to incorporating constraints. Each of these
approaches are first applied to equality constraints and then extended to
inequality constraints. We discuss methods for dealing with nonlinear
constraints and for constraining the state prediction. Finally, some
experiments are provided to indicate the usefulness of such methods.


title: Constraining the growth factor with baryon oscillations

abstract:
  The growth factor of linear fluctuations is probably one of the least known
quantity in observational cosmology. Here we discuss the constraints that
baryon oscillations in galaxy power spectra from future surveys can put on a
conveniently parametrized growth factor. We find that spectroscopic surveys of
$5000 deg^2$ extending to $z \approx 3$ could estimate the growth index
$\gamma$ within 0.06; a similar photometric survey would give
$\Delta\gamma\approx 0.15$. This test provides an important consistency check
for standard cosmological model and could constrain modified gravity models. We
discuss the errors and the figure of merit for various combinations of redshift
errors and survey size.


title: Cubical convex ear decompositions

abstract:
  We consider the problem of constructing a convex ear decomposition for a
poset. The usual technique, first used by Nyman and Swartz, starts with a
CL-labeling and uses this to shell the `ears' of the decomposition. We
axiomatize the necessary conditions for this technique as a "CL-ced" or
"EL-ced". We find an EL-ced of the d-divisible partition lattice, and a closely
related convex ear decomposition of the coset lattice of a relatively
complemented group. Along the way, we construct new EL-labelings of both
lattices. The convex ear decompositions so constructed are formed by face
lattices of hypercubes.
  We then proceed to show that if two posets P_1 and P_2 have convex ear
decompositions (CL-ceds), then their products P_1 \times P_2, P_1 \lrtimes P_2,
and P_1 \urtimes P_2 also have convex ear decompositions (CL-ceds). An
interesting special case is: if P_1 and P_2 have polytopal order complexes,
then so do their products.


title: Polyhedral tori with minimal coordinates

abstract:
  We give explicit realizations with small integer coordinates for all
triangulated tori with up to 12 vertices. In particular, we provide
coordinate-minimal realizations in general position for all triangulations of
the torus with 7, 8, 9, and 10 vertices. For the unique 7-vertex triangulation
of the torus we show that all corresponding 72 oriented matroids are realizable
in the 6x6x6-cube. Moreover, we present polyhedral tori with 8 vertices in the
2x2x2-cube, general position realizations of triangulated tori with 8 vertices
in the 2x2x3-cuboid as well as polyhedral tori with 9 and 10 vertices in the
1x2x2-cuboid.


title: Quantum Theory on Lobatchevski Spaces

abstract:
  In this paper we set up a general formalism to deal with quantum theories on
a Lobatchevski space, i.e. a spatial manifold that is homogeneous, isotropic
and has negative curvature. The heart of our approach is the construction of a
suitable basis of plane waves which are eigenfunctions of the Laplace-Beltrami
operator relative to the geometry of the curved space. These functions were
previously introduced in the mathematical literature in the context of group
theory; here we revisit and adapt the formalism in a way specific for quantum
mechanics. Our developments render dealing with Lobatchevski spaces, which used
to be quite difficult and source of controversies, easily tractable.
Applications to the Milne and de Sitter universes are discussed as examples.


title: Unoccupied states of individual silver clusters and chains on Ag(111)

abstract:
  Size-selected silver clusters on Ag(111) were fabricated with the tip of a
scanning tunneling microscope. Unoccupied electron resonances give rise to
image contrast and spectral features which shift toward the Fermi level with
increasing cluster size. Linear assemblies exhibit higher resonance energies
than equally sized compact assemblies. Density functional theory calculations
reproduce the observed energies and enable an assignment of the resonances to
hybridized atomic 5s and 5p orbitals with silver substrate states.


title: Comments On " Orbits of automorphism groups of fields"

abstract:
  Let $R$ be a commutative $k-$algebra over a field $k$. Assume $R$ is a
noetherian, infinite, integral domain. The group of $k-$automorphisms of
$R$,i.e.$Aut_k(R)$ acts in a natural way on $(R-k)$.In the first part of this
article, we study the structure of $R$ when the orbit space $(R-k)/Aut_k(R)$ is
finite.We note that most of the results, not particularly relevent to fields,
in [1,\S 2] hold in this case as well. Moreover, we prove that $R$ is a field.
In the second part, we study a special case of the Conjecture 2.1 in [1] : If
$K/k$ is a non trivial field extension where $k$ is algebraically closed and
$\mid (K-k)/Aut_k(K) \mid = 1$ then $K$ is algebraically closed. In the end, we
give an elementary proof of [1,Theorem 1.1] in case $K$ is finitely generated
over its prime subfield.


title: The twist subgroup of the mapping class group of a nonorientable surface

abstract:
  Let T(N) be the subgroup of the mapping class group of a nonorientable
surface N (possibly with punctures and/or boundary components) generated by
twists about two-sided circles. We obtain a simple generating set for T(N). As
an application we compute the first homology group (abelianization) of T(N).


title: Supersymmetric SU(5) GUT with Stabilized Moduli

abstract:
  We construct a minimal example of a supersymmetric grand unified model in a
toroidal compactification of type I string theory with magnetized D9-branes.
All geometric moduli are stabilized in terms of the background internal
magnetic fluxes which are of "oblique" type (mutually non-commuting). The gauge
symmetry is just SU(5) and the gauge non-singlet chiral spectrum contains only
three families of quarks and leptons transforming in the $10+{\bar 5}$
representations.


title: The Broad Line Region of Quasars

abstract:
  The last decade saw long-awaited improvements in our understanding of active
galactic nuclei (AGN) spectral properties. This contribution reviews some
important observational results obtained from optical and UV data as well as
constraints on physical parameters that control the structure and dynamics of
the Broad Line Region.


title: Analogies between analysis on foliated spaces and arithmetic geometry

abstract:
  We point out analogies between (a) the explicit formulas in analytic number
theory and transversal index theory, (b) Lichtenbaum's recent conjectures on
special values of Hasse-Weil zeta functions and a formula for special values of
Ruelle zeta functions, (c) work of Cramer on the zeroes of the Riemann zeta
function and a result of Chazarain on the trace of a wave operator. These
analogies suggest certain problems in the analysis on foliated spaces. The
paper is mostly a review of previous work but the ideas concerning (c) are new.


title:
The importance of probability interference in social science: rationale
  and experiment

abstract:
  Probability interference is a fundamental characteristic of quantum
mechanics. In this paper we attempt to show with the help of some examples,
where this fundamental trait of quantum physics can be found back in a social
science environment. In order to support our thesis that interference can
possibly be found back in many other macro-scopic areas, we proceed in setting
up an experimental test.


title:
High-Precision Thermodynamic and Critical Properties from Tensor
  Renormalization-Group Flows

abstract:
  The recently developed tensor renormalization-group (TRG) method provides a
highly precise technique for deriving thermodynamic and critical properties of
lattice Hamiltonians. The TRG is a local coarse-graining transformation, with
the elements of the tensor at each lattice site playing the part of the
interactions that undergo the renormalization-group flows. These tensor flows
are directly related to the phase diagram structure of the infinite system,
with each phase flowing to a distinct surface of fixed points. Fixed-point
analysis and summation along the flows give the critical exponents, as well as
thermodynamic functions along the entire temperature range. Thus, for the
ferromagnetic triangular lattice Ising model, the free energy is calculated to
better than 10^-5 along the entire temperature range. Unlike previous
position-space renormalization-group methods, the truncation (of the tensor
index range D) in this general method converges under straightforward and
systematic improvements. Our best results are easily obtained with D = 24,
corresponding to 4624-dimensional renormalization-group flows.


title:
The Color Antisymmetric Ghost Propagator and One-Loop Vertex
  Renormalization

abstract:
  The color matrix elements of the ghost triangle diagram that appears in the
triple gluon vertex and the ghost-ghost-gluon triangle diagram that appears in
the ghost-gluon-ghost vertex are calculated. The ghost-ghost-gluon triangle
contains a loop consisting of two color diagonal ghosts and one gluon and a
loop consisting of two color antisymmetric ghosts and one gluon. Consequently,
the pQCD argument in the infrared region based on the one particle irreducible
diagram should be modified. Implications for the Kugo-Ojima color confinement
and the QCD running coupling are discussed.


title:
Evidence for Quasar Activity Triggered by Galaxy Mergers in HST
  Observations of Dust-reddened Quasars

abstract:
  We present Hubble ACS images of thirteen dust reddened Type-1 quasars
selected from the FIRST/2MASS Red Quasar Survey. These quasars have high
intrinsic luminosities after correction for dust obscuration (-23.5 > M_B >
-26.2 from K-magnitude). The images show strong evidence of recent or ongoing
interaction in eleven of the thirteen cases, even before the quasar nucleus is
subtracted. None of the host galaxies are well fit by a simple elliptical
profile. The fraction of quasars showing interaction is significantly higher
than the 30% seen in samples of host galaxies of normal, unobscured quasars.
There is a weak correlation between the amount of dust reddening and the
magnitude of interaction in the host galaxy, measured using the Gini
coefficient and the Concentration index. Although few host galaxy studies of
normal quasars are matched to ours in intrinsic quasar luminosity, no evidence
has been found for a strong dependence of merger activity on host luminosity in
samples of the host galaxies of normal quasars. We thus believe that the high
merger fraction in our sample is related to their obscured nature, with a
significant amount of reddening occurring in the host galaxy. The red quasar
phenomenon seems to have an evolutionary explanation, with the young quasar
spending the early part of its lifetime enshrouded in an interacting galaxy.
This might be further indication of a link between AGN and starburst galaxies.


title: Absolute Momentum Calibration of the HARP TPC

abstract:
  In the HARP experiment the large-angle spectrometer is using a cylindrical
TPC as main tracking and particle identification detector. The momentum scale
of reconstructed tracks in the TPC is the most important systematic error for
the majority of kinematic bins used for the HARP measurements of the
double-differential production cross-section of charged pions in proton
interactions on nuclear targets at large angle. The HARP TPC operated with a
number of hardware shortfalls and operational mistakes. Thus it was important
to control and characterize its momentum calibration. While it was not possible
to enter a direct particle beam into the sensitive volume of the TPC to
calibrate the detector, a set of physical processes and detector properties
were exploited to achieve a precise calibration of the apparatus. In the
following we recall the main issues concerning the momentum measurement in the
HARP TPC, and describe the cross-checks made to validate the momentum scale. As
a conclusion, this analysis demonstrates that the measurement of momentum is
correct within the published precision of 3%.


title: Observations of VHE gamma-Ray Sources with the MAGIC Telescope

abstract:
  The MAGIC telescope with its 17m diameter mirror is today the largest
operating single-dish Imaging Air Cherenkov Telescope (IACT). It is located on
the Canary Island La Palma, at an altitude of 2200m above sea level, as part of
the Roque de los Muchachos European Northern Observatory. The MAGIC telescope
detects celestial very high energy gamma-radiation in the energy band between
about 50 GeV and 10 TeV. Since Autumn of 2004 MAGIC has been taking data
routinely, observing various objects like supernova remnants (SNRs), gamma-ray
binaries, Pulsars, Active Galactic Nuclei (AGN) and Gamma-ray Bursts (GRB). We
briefly describe the observational strategy, the procedure implemented for the
data analysis, and discuss the results for individual sources. An outlook to
the construction of the second MAGIC telescope is given.


title:
Comparison of reduced-order, sequential and variational data
  assimilation methods in the tropical Pacific Ocean

abstract:
  This paper presents a comparison of two reduced-order, sequential and
variational data assimilation methods: the SEEK filter and the R-4D-Var. A
hybridization of the two, combining the variational framework and the
sequential evolution of covariance matrices, is also preliminarily investigated
and assessed in the same experimental conditions. The comparison is performed
using the twin-experiment approach on a model of the Tropical Pacific domain.
The assimilated data are simulated temperature profiles at the locations of the
TAO/TRITON array moorings. It is shown that, in a quasi-linear regime, both
methods produce similarly good results. However the hybrid approach provides
slightly better results and thus appears as potentially fruitful. In a more
non-linear regime, when Tropical Instability Waves develop, the global nature
of the variational approach helps control model dynamics better than the
sequential approach of the SEEK filter. This aspect is probably enhanced by the
context of the experiments in that there is a limited amount of assimilated
data and no model error.


title: Pure Anderson Motives and Abelian \tau-Sheaves

abstract:
  Pure t-motives were introduced by G. Anderson as higher dimensional
generalizations of Drinfeld modules, and as the appropriate analogs of abelian
varieties in the arithmetic of function fields. In order to construct moduli
spaces for pure t-motives the second author has previously introduced the
concept of abelian \tau-sheaf. In this article we clarify the relation between
pure t-motives and abelian \tau-sheaves. We obtain an equivalence of the
respective quasi-isogeny categories. Furthermore, we develop the elementary
theory of both structures regarding morphisms, isogenies, Tate modules, and
local shtukas. The later are the analogs of p-divisible groups.


title:
Moduli Evolution in the Presence of Matter Fields and Flux
  Compactification

abstract:
  We provide a detailed analysis of the dynamics of moduli fields in the KKLT
scenario coupled to a Polonyi field, which plays the role of a hidden matter
sector field. It was previously shown that such matter fields can uplift AdS
vacua to Minkowski or de Sitter vacua. Additionally, we take a background fluid
into account (which can be either matter or radiation), which aids moduli
stabilisation. Our analysis shows that the presence of the matter field further
aids stabilisation, due to a new scaling regime. We study the system both
analytically and numerically.


title:
How a plantar pressure-based, tongue-placed tactile biofeedback modifies
  postural control mechanisms during quiet standing

abstract:
  The purpose of the present study was to determine the effects of a plantar
pressure-based, tongue-placed tactile biofeedback on postural control
mechanisms during quiet standing. To this aim, sixteen young healthy adults
were asked to stand as immobile as possible with their eyes closed in two
conditions of No-biofeedback and Biofeedback. Centre of foot pressure (CoP)
displacements, recorded using a force platform, were used to compute the
horizontal displacements of the vertical projection the centre of gravity
(CoGh) and those of the difference between the CoP and the vertical projection
of the CoG (CoP-CoGv). Altogether, the present findings suggest that the main
way the plantar pressure-based, tongue-placed tactile biofeedback improves
postural control during quiet standing is via both a reduction of the
correction thresholds and an increased efficiency of the corrective mechanism
involving the CoGh displacements.


title:
Infraparticle Scattering States in Non-Relativistic QED: II. Mass Shell
  Properties

abstract:
  We study the infrared problem in the usual model of QED with non-relativistic
matter. We prove spectral and regularity properties characterizing the mass
shell of an electron and one-electron infraparticle states of this model. Our
results are crucial for the construction of infraparticle scattering states,
which are treated in a separate paper.


title: LDPC codes from Singer cycles

abstract:
  The main goal of coding theory is to devise efficient systems to exploit the
full capacity of a communication channel, thus achieving an arbitrarily small
error probability. Low Density Parity Check (LDPC) codes are a family of block
codes--characterised by admitting a sparse parity check matrix--with good
correction capabilities. In the present paper the orbits of subspaces of a
finite projective space under the action of a Singer cycle are investigated.


title:
Reduced-order 4D-Var: a preconditioner for the Incremental 4D-Var data
  assimilation method

abstract:
  This study demonstrates how the incremental 4D-Var data assimilation method
can be applied efficiently preconditione d in an application to an
oceanographic problem. The approach consists in performing a few iterations of
the reduced-order 4D-Var prior to the incremental 4D-Var in the full space in
order to achieve faster convergence. An application performed in the tropical
Pacific Ocean, with assimilation of TAO temperature data, shows the method to
be both feasible and efficient. It allows the global cost of the assimilation
to be reduced by a factor of 2 without affecting the quality of the solution.


title: Pure Anderson Motives over Finite Fields

abstract:
  In the arithmetic of function fields Drinfeld modules play the role that
elliptic curves take on in the arithmetic of number fields. As higher
dimensional generalizations of Drinfeld modules, and as the appropriate
analogues of abelian varieties, G. Anderson introduced pure t-motives. In this
article we study the arithmetic of the later. We investigate which pure
t-motives are semisimple, that is, isogenous to direct sums of simple ones. We
give examples for pure t-motives which are not semisimple. Over finite fields
the semisimplicity is equivalent to the semisimplicity of the endomorphism
algebra, but also this fails over infinite fields. Still over finite fields we
study the endomorphism rings of pure t-motives and criteria for the existence
of isogenies. We obtain answers which are similar to Tate's famous results for
abelian varieties.


title:
Non-equilibrium emission of complex fragments from p+Au collisions at
  2.5 GeV proton beam energy

abstract:
  Energy and angular dependence of double differential cross sections
d$^2\sigma$/d$\Omega$dE was measured for reactions induced by 2.5 GeV protons
on Au target with isotopic identification of light products (H, He, Li, Be, and
B) and with elemental identification of heavier intermediate mass fragments (C,
N, O, F, Ne, Na, Mg, and Al). It was found that two different reaction
mechanisms give comparable contributions to the cross sections. The
intranuclear cascade of nucleon-nucleon collisions followed by evaporation from
an equilibrated residuum describes low energy part of the energy distributions
whereas another reaction mechanism is responsible for high energy part of the
spectra of composite particles. Phenomenological model description of the
differential cross sections by isotropic emission from two moving sources led
to a very good description of all measured data. Values of the extracted
parameters of the emitting sources are compatible with the hypothesis claiming
that the high energy particles emerge from pre-equilibrium processes consisting
in a breakup of the target into three groups of nucleons; small, fast and hot
fireball of $\sim$ 8 nucleons, and two larger, excited prefragments, which
emits the light charged particles and intermediate mass fragments. The smaller
of them contains $\sim$ 20 nucleons and moves with velocity larger than the CM
velocity of the proton projectile and the target. The heavier prefragment
behaves similarly as the heavy residuum of the intranuclear cascade of
nucleon-nucleon collisions. %The mass and charge dependence of the total
production cross %sections was extracted from the above analysis for all
observed %reaction products. This dependence follows the power low behavior
%(A$^{-\tau}$ or Z$^{-\tau}$).


title:
FCNC $B_s$ and $\Lambda_b$ transitions: Standard Model versus a single
  Universal Extra Dimension scenario

abstract:
  We study the FCNC $B_s \to \phi \gamma, \phi \nu \bar \nu$ and $\Lambda_b \to
\Lambda \gamma, \Lambda \nu \bar \nu$ transitions in the Standard Model and in
a scenario with a single Universal Extra Dimension. In particular, we focus on
the present knowledge of the hadronic uncertainties and on possible
improvements. We discuss how the measurements of these modes can be used to
constrain the new parameter involved in the extra dimensional scenario, the
radius $R$ of the extra dimension, completing the information available from
B-factories. The rates of these $b \to s$ induced decays are within the reach
of new experiments, such as LHCb.


title: Lepton Flavour Violation at the ILC

abstract:
  We explore the possibility of detecting lepton flavour violation, now a well
established experimental fact, at the International Linear Collider. Using a
model independent approach we conclude that, given all experimental constraints
available, there is still room to detect lepton flavour violation at the ILC.


title:
A New Supersensitive Flame Detector and its Use for Early Forest Fire
  Detection

abstract:
  A new flame detector, three orders of magnitude more powerful than the
existing ones, is presented. This detector needs to be mass-produced for its
use in order to be incorporated in an early forest fire detection system. A
project able to implement its use to overcome the forest fire emergency is
described.


title: On the behaviour of B and Be stars at low metallicity

abstract:
  We present new results obtained with the VLT GIRAFFE for a large sample of B
and Be stars belonging to the Magellanic Clouds, i.e. at low metallicity.
First, we show the effects of the metallicity of the environment on their
rotation (linear, angular, and at the ZAMS). Second, we present the analysis of
the effects of metallicity and evolution on the appearance of Be stars. We also
new present results about the proportions of Be stars to B stars. Third, by
cross-correlation with large photometric surveys such as MACHO and OGLE, we
report on the detection for the first time of short-term multi-periodicity in 9
Be stars in the Small Magellanic Cloud, which can be interpreted in terms of
pulsations.


title:
A priori bounds and a Liouville theorem on a half-space for higher order
  elliptic Dirichlet problems

abstract:
  We consider the $2m$-th order elliptic boundary value problem $Lu=f(x,u)$ on
a bounded smooth domain $\Omega$ in $R^N$ with Dirichlet boundary conditions.
The operator $L$ is a uniformly elliptic operator of order $2m$. We assume that
for $s\to \pm\infty$ the nonlinearity $f(x,s)$ behaves like $|s|^q$ multiplied
by a continuous and positive function of $x$. Here the exponent $q$ is
subcritical, i.e., $q>1$ if $N<=2m$, $1<q<\frac{N+2m}{N-2m}$ if $N>2m$. We
prove a priori bounds, i.e, we show that the $L^\infty$-norm of every solution
$u$ is bounded by a constant independent of $u$. The solutions are allowed to
be sign-changing. The proof is done by a blow-up argument which relies on the
following new Liouville-type theorem on a half-space: if $u$ is a classical,
bounded, non-negative solution of $(-\Delta)^m u = u^q$ in a half-space with
Dirichlet boundary conditions and if $q>1$ is subcritical then $u$ vanishes
identically.


title: Soliton Stability in a Generalized Sine-Gordon Potential

abstract:
  We study stability of a generalized sine-Gordon model with two coupled scalar
fields in two dimensions. Topological soliton solutions are found from the
first-order equations that solve the equations of motion. The perturbation
equations can be cast in terms of a Schrodinger-like operators for fluctuations
and their spectra are calculated.


title: On the nature of early-type emission line objects in NGC6611

abstract:
  The number and the nature of emission line stars in the young open cluster
NGC6611 is still the object of debates. Due to the presence of a strong and
variable nebulosity in the cluster, the number of emission line stars is highly
depending on the technique and the resolution used for the observations. Thanks
to observations with the ESO-WFI, in slitless spectroscopic mode, and with the
VLT-GIRAFFE we have been able to disentangle the circumstellar and nebular
emissions. We confirm the small number of true emission line objects and we
precise their nature: mainly Herbig Be stars.


title:
Pseudo-Random Fluctuations, Stochastic Cooperativity and Burstiness in
  Dynamically Unstable High-Dimensional Biochemical Networks

abstract:
  The goal of this paper is to outline a scenario of emerging stochasticity in
high-dimensional highly nonlinear systems, such as genetic regulatory networks
(GRN). We focus attention on the fact that in such systems confluence of all
the factors necessary for gene expression is a comparatively rare event, and
only massive redundancy makes such events sufficiently frequent. An immediate
consequence of this rareness is burstiness in mRNA and protein copy numbers, a
well known experimentally observed effect. We introduce the concept of
stochastic cooperativity and show that this phenomenon is a natural consequence
of high dimensionality coupled with highly nonlinearity of a dynamical system.
In mathematical terms, burstiness is associated with heavy-tailed probability
distributions of stochastic processes describing the dynamics of the system.
The sequence of stochastic cooperativity events allows for transition from
continuous deterministic dynamics expressed in terms of ordinary differential
equations (ODE) to discrete stochastic dynamics expressed in terms of Langevin
and Fokker-Plank equations. We demonstrate also that high-dimensional nonlinear
systems, even in the absence of explicit mechanisms for suppressing inherent
instability, may nevertheless reside in a state of stationary pseudo-random
fluctuations which for all practical purposes may be regarded as stochastic
process. This type of stochastic behavior is an inherent property of such
systems and requires neither an external random force, nor highly specialized
conditions of bistability.


title: A reduced-order strategy for 4D-Var data assimilation

abstract:
  This paper presents a reduced-order approach for four-dimensional variational
data assimilation, based on a prior EO F analysis of a model trajectory. This
method implies two main advantages: a natural model-based definition of a mul
tivariate background error covariance matrix $\textbf{B}_r$, and an important
decrease of the computational burden o f the method, due to the drastic
reduction of the dimension of the control space. % An illustration of the
feasibility and the effectiveness of this method is given in the academic
framework of twin experiments for a model of the equatorial Pacific ocean. It
is shown that the multivariate aspect of $\textbf{B}_r$ brings additional
information which substantially improves the identification procedure. Moreover
the computational cost can be decreased by one order of magnitude with regard
to the full-space 4D-Var method.


title: Sudakov resummation in QCD

abstract:
  In this PhD thesis, we analyze and generalize the renormalization group
approach to the resummation of large logarithms in the perturbative expansion
due to soft and collinear multiparton emissions. In particular, we present a
generalization of this approach to prompt photon production. It is interesting
to see that also with the more intricate two-scale kinematics that
characterizes prompt photon production in the soft limit, it remains true that
resummation simply follows from general kinematic properties of the phase
space. Also, this approach does not require a separate treatment of individual
colour structures when more than one colour structure contributes to fixed
order results. However, the resummation formulae obtained here turn out to be
less predictive than previous results: this depends on the fact that here
neither specific factorization properties of the cross section in the soft
limit is assumed, nor that soft emission satisfies eikonal-like relations. We
also derive resumation formulae to all logarithmic accuracy and valid for all
values of rapidity for the prompt photon production and the Drell-Yan rapidity
distributions. We show that for the fixed-target experiment E866/NuSea, the NLL
resummation corrections are comparable to NLO fixed-order corrections and are
crucial to obtain agreement with the data. Finally we outline also possible
future applications of the renormalization group approach.


title:
An analytically solvable model of the effect of magnetic breakdown on
  angle-dependent magnetoresistance in a quasi-two-dimensional metal

abstract:
  We have developed an analytical model of angle-dependent magnetoresistance
oscillations (AMROs) in a quasi-two-dimensional metal in which magnetic
breakdown occurs. The model takes account of all the contributions from
quasiparticles undergoing both magnetic breakdown and Bragg reflection at each
junction and allows extremely efficient simulation of data which can be
compared with recent experimental results on the organic metal
kappa-ET2Cu(NCS)2. AMROs resulting from both closed and open orbits emerge
naturally at low field, and the model enables the transition to breakdown-AMROs
with increasing field to be described in detail.


title:
Microlensing variability in the gravitationally lensed quasar Q2237+0305
  = the Einstein Cross, I. Spectrophotometric monitoring with the VLT

abstract:
  We present the results of the first long-term (2.2 years) spectroscopic
monitoring of a gravitationally lensed quasar, namely the Einstein Cross
Q2237+0305. The goal of this paper is to present the observational facts to be
compared in follow-up papers with theoretical models to constrain the inner
structure of the source quasar. We spatially deconvolve deep VLT/FORS1 spectra
to accurately separate the spectrum of the lensing galaxy from the spectra of
the quasar images. Accurate cross-calibration of the 58 observations at
31-epoch from October 2004 to December 2006 is carried out with non-variable
foreground stars observed simultaneously with the quasar. The quasar spectra
are further decomposed into a continuum component and several broad emission
lines to infer the variations of these spectral components. We find prominent
microlensing events in the quasar images A and B, while images C and D are
almost quiescent on a timescale of a few months. The strongest variations are
observed in the continuum of image A. Their amplitude is larger in the blue
(0.7 mag) than in the red (0.5 mag), consistent with microlensing of an
accretion disk. Variations in the intensity and profile of the broad emission
lines are also reported, most prominently in the wings of the CIII] and center
of the CIV emission lines. During a strong microlensing episode observed in
June 2006 in quasar image A, the broad component of the CIII] is more highly
magnified than the narrow component. In addition, the emission lines with
higher ionization potentials are more magnified than the lines with lower
ionization potentials, consistent with the results obtained with reverberation
mapping. Finally, we find that the V-band differential extinction by the lens,
between the quasar images, is in the range 0.1-0.3 mag.


title:
Theory of biphoton generation in a single-resonant optical parametric
  oscillator far below threshold

abstract:
  We present a quantum-theoretical treatment of biphoton generation in
single-resonant type-II parametric down-conversion. The nonlinear medium is
continuously pumped and is placed inside a cavity which is resonant for the
signal field, but nonresonant for the idler deflected by an intra-cavity
polarizing beam splitter. The intensity of the classical pump is assumed to be
sufficiently low in order to yield a biphoton production rate that is small
compared to the cavity loss rate. Explicit expressions are derived for the rate
of biphoton generation and for the biphoton wave function. The output spectra
of the signal and idler field are determined, as well as the second-order
signal-idler cross-correlation function which is shown to be asymmetric with
respect to the time delay. Due to frequency entanglement in the signal-idler
photon pair, the idler spectrum is found to reveal the longitudinal mode
structure of the cavity, even though the idler field is not resonant.


title: Behavioral Portfolio Selection in Continuous Time

abstract:
  This paper formulates and studies a general continuous-time behavioral
portfolio selection model under Kahneman and Tversky's (cumulative) prospect
theory, featuring S-shaped utility (value) functions and probability
distortions. Unlike the conventional expected utility maximization model, such
a behavioral model could be easily mis-formulated (a.k.a. ill-posed) if its
different components do not coordinate well with each other. Certain classes of
an ill-posed model are identified. A systematic approach, which is
fundamentally different from the ones employed for the utility model, is
developed to solve a well-posed model, assuming a complete market and general
It\^o processes for asset prices. The optimal terminal wealth positions,
derived in fairly explicit forms, possess surprisingly simple structure
reminiscent of a gambling policy betting on a good state of the world while
accepting a fixed, known loss in case of a bad one. An example with a two-piece
CRRA utility is presented to illustrate the general results obtained, and is
solved completely for all admissible parameters. The effect of the behavioral
criterion on the risky allocations is finally discussed.


title: Triangulating the Real Projective Plane

abstract:
  We consider the problem of computing a triangulation of the real projective
plane P2, given a finite point set S={p1, p2,..., pn} as input. We prove that a
triangulation of P2 always exists if at least six points in S are in general
position, i.e., no three of them are collinear. We also design an algorithm for
triangulating P2 if this necessary condition holds. As far as we know, this is
the first computational result on the real projective plane.


title: The Lyapunov spectrum of some parabolic systems

abstract:
  We study the Hausdorff dimension spectrum for Lyapunov exponents for a class
of interval maps which includes several non-hyperbolic situations. We also
analyze the level sets of points with given lower and upper Lyapunov exponents
and, in particular, with zero lower Lyapunov exponent. We prove that the level
set of points with zero exponent has full Hausdorff dimension, but carries no
topological entropy.


title:
Distributed Space Time Codes with Low Decoding Complexity for
  Asynchronous Relay Networks

abstract:
  Recently Li and Xia have proposed a transmission scheme for wireless relay
networks based on the Alamouti space time code and orthogonal frequency
division multiplexing to combat the effect of timing errors at the relay nodes.
This transmission scheme is amazingly simple and achieves a diversity order of
two for any number of relays. Motivated by its simplicity, this scheme is
extended to a more general transmission scheme that can achieve full
cooperative diversity for any number of relays. The conditions on the
distributed space time code (DSTC) structure that admit its application in the
proposed transmission scheme are identified and it is pointed out that the
recently proposed full diversity four group decodable DSTCs from precoded
co-ordinate interleaved orthogonal designs and extended Clifford algebras
satisfy these conditions. It is then shown how differential encoding at the
source can be combined with the proposed transmission scheme to arrive at a new
transmission scheme that can achieve full cooperative diversity in asynchronous
wireless relay networks with no channel information and also no timing error
knowledge at the destination node. Finally, four group decodable distributed
differential space time codes applicable in this new transmission scheme for
power of two number of relays are also provided.


title: Physics of EtaPrime->Pi+Pi-Eta and EtaPrime->Pi+Pi-Pi0 decays

abstract:
  The article describes experimental status of EtaPrime->Pi+Pi-Eta and
EtaPrime->Pi+Pi-Pi0 decays. A theoretical framework used for description of the
decays mechanism is also reviewed. The possibilities for the measurements with
WASA-at-COSY are mentioned.


title: Coronae in the Coronet: A very deep X-ray look into a stellar nursery

abstract:
  In order to study the X-ray properties of young stellar objects (YSOs), we
analyze an exceptionally sensitive Chandra dataset of the Coronet cluster in
the CrA star-forming region, achieving a limiting luminosity of LXmin=5E26
erg/sec for lightly absorbed sources. This dataset represents one of the most
sensitive X-ray observations ever obtained of a star-forming region. The X-ray
data are used to investigate the membership status of tentative members of the
region, to derive plasma temperatures and X-ray luminosities of the YSOs, and
to investigate variability on the timescale of several years. 46 of the 92
X-ray sources in the merged Chandra image can be identified with optical or
near/mid-infrared counterparts. X-ray emission is detected from all of the
previously known optically visible late-type (spectral types G to M) stellar
cluster members, from five of the eight brown dwarf candidates, and from nine
embedded objects ("protostars") with class 0, class I, or flat-spectrum SEDs in
the field of view. While the Herbig Ae/Be stars TY CrA and R CrA, a close
companion of the B9e star HD 176386, and the F0e star T CrA are detected, no
X-ray emission is found from any of the Herbig-Haro (HH) objects or the
protostellar cores without infrared source. We find indications for diffuse
X-ray emission near R CrA / IRS 7. The observed X-ray properties of the Coronet
YSOs are consistent with coronal activity; no soft spectral components hinting
towards X-ray emission from accretion shocks were found. The X-ray emission of
the AeBe stars TY CrA and HD 176386 originates probably from close late-type
companions. The Ae star R Cra shows a peculiar X-ray spectrum and an extremely
hot plasma temperature. Finally, we discuss the differences of the X-ray
properties of YSOs in different evolutionary stages.


title:
Hamiltonians on discrete structures: Jumps of the integrated density of
  states and uniform convergence

abstract:
  We study equivariant families of discrete Hamiltonians on amenable geometries
and their integrated density of states (IDS). We prove that the eigenspace of a
fixed energy is spanned by eigenfunctions with compact support. The size of a
jump of the IDS is consequently given by the equivariant dimension of the
subspace spanned by such eigenfunctions. From this we deduce uniform
convergence (w.r.t. the spectral parameter) of the finite volume approximants
of the IDS. Our framework includes quasiperiodic operators on Delone sets,
periodic and random operators on quasi-transitive graphs, and operators on
percolation graphs.


title: Resolution Studies of GEM/Timepix Detector with 5 GeV electrons

abstract:
  This contribution investigates a prototype of a TPC readout with a highly
pixelated CMOS ASIC, which is an option for charged particles tracking of the
ILC. A triple GEM stack was joined with a TimePix and MediPix2 chip (pixel size
of 55$\times$55 $\mu m^2$) and its readout properties were investigated with 5
GeV electrons. The spatial resolution of the cluster center reconstruction was
determined as a function of drift distance using different cluster alhoritms
and compared with Monte Carlo predictions.


title: On the p-adic Leopoldt Transform of a power series

abstract:
  In this paper we give a bound for the Iwasawa lambda invariant of an abelian
number field attached to the cyclotomic Z_p-extension of that field. We also
give some properties of Iwaswa power series attached to p-adic L-functions.


title:
The Hottest Horizontal-Branch Stars in omega Centauri - Late Hot Flasher
  vs. Helium Enrichment

abstract:
  UV observations of some massive globular clusters uncovered a significant
population of very hot stars below the hot end of the horizontal branch (HB),
the so-called blue hook stars. This feature might be explained either as
results of the late hot flasher scenario where stars experience the helium
flash while on the white dwarf cooling curve or by the progeny of the
helium-enriched sub-population recently postulated to exist in some clusters.
Moderately high resolution spectra of stars at the hot end of the blue HB in
omega Cen were analysed for atmospheric parameters and abundances using LTE and
Non-LTE model atmospheres. In the temperature range 30,000K to 50,000K we find
that 35% of our stars are helium-poor (log(n_He/n_H) < -2), 51% have solar
helium abundance within a factor of 3 (-1.5 <= log(n_He/n_H) <= -0.5) and 14%
are helium-rich (log(n_He/n_H)> -0.4). We also find carbon enrichment in step
with helium enrichment, with a maximum carbon enrichment of 3% by mass. At
least 14% of the hottest HB stars in omega Cen show helium abundances well
above the highest predictions from the helium enrichment scenario (Y = 0.42
corresponding to log(n_He/n_H) ~ -0.74). In addition, the most helium-rich
stars show strong carbon enrichment as predicted by the late hot flasher
scenario. We conclude that the helium-rich HB stars in omega Cen cannot be
explained solely by the helium-enrichment scenario invoked to explain the blue
main sequence. (Abridged)


title: Suppression of Supergravity Anomalies in Conformal Sequestering

abstract:
  We show that the anomaly-mediated supersymmetry breaking via the Kahler and
sigma-model anomalies is suppressed by conformal dynamics in the supersymmetry
breaking sector.


title: Trapping and cooling of rf-dressed atoms in a quadrupole magnetic field

abstract:
  We observe the spontaneous evaporation of atoms confined in a bubble-like
rf-dressed trap (Zobay and Garraway, 2001). The atoms are confined in a
quadrupole magnetic trap and are dressed by a linearly polarized rf field. The
evaporation is related to the presence of holes in the trap, at the positions
where the rf coupling vanishes, due to its vectorial character. The final
temperature results from a competition between residual heating and evaporation
efficiency, which is controlled via the height of the holes with respect to the
bottom of the trap. The experimental data are modeled by a Monte-Carlo
simulation predicting a small increase in phase space density limited by the
heating rate. This increase was within the phase space density determination
uncertainty of the experiment.


title: Trapping Horizons as inner boundary conditions for black hole spacetimes

abstract:
  We present a set of inner boundary conditions for the numerical construction
of dynamical black hole space-times, when employing a 3+1 constrained evolution
scheme and an excision technique. These inner boundary conditions are
heuristically motivated by the dynamical trapping horizon framework and are
enforced in an elliptic subsystem of the full Einstein equation. In the
stationary limit they reduce to existing isolated horizon boundary conditions.
A characteristic analysis completes the discussion of inner boundary conditions
for the radiative modes.


title:
Thermal denaturation of fluctuating finite DNA chains: the role of
  bending rigidity in bubble nucleation

abstract:
  Statistical DNA models available in the literature are often effective models
where the base-pair state only (unbroken or broken) is considered. Because of a
decrease by a factor of 30 of the effective bending rigidity of a sequence of
broken bonds, or bubble, compared to the double stranded state, the inclusion
of the molecular conformational degrees of freedom in a more general mesoscopic
model is needed. In this paper we do so by presenting a 1D Ising model, which
describes the internal base pair states, coupled to a discrete worm like chain
model describing the chain configurations [J. Palmeri, M. Manghi, and N.
Destainville, Phys. Rev. Lett. 99, 088103 (2007)]. This coupled model is
exactly solved using a transfer matrix technique that presents an analogy with
the path integral treatment of a quantum two-state diatomic molecule. When the
chain fluctuations are integrated out, the denaturation transition temperature
and width emerge naturally as an explicit function of the model parameters of a
well defined Hamiltonian, revealing that the transition is driven by the
difference in bending (entropy dominated) free energy between bubble and
double-stranded segments. The calculated melting curve (fraction of open base
pairs) is in good agreement with the experimental melting profile of
polydA-polydT. The predicted variation of the mean-square-radius as a function
of temperature leads to a coherent novel explanation for the experimentally
observed thermal viscosity transition. Finally, the influence of the DNA strand
length is studied in detail, underlining the importance of finite size effects,
even for DNA made of several thousand base pairs.


title:
Two loop finiteness of Higgs mass and potential in the gauge-Higgs
  unification

abstract:
  The zero mode of an extra-dimensional component of gauge potentials serves as
a 4D Higgs field in the gauge-Higgs unification. We examine QED on $M^4 \times
S^1$ and determine the mass and potential of a 4D Higgs field (the $A_5$
component) at the two loop level with gauge invariant reguralization. It is
seen that the mass is free from divergences and independent of the
renormalization scheme.


title:
Manifestation of Defects in Raman Effect of Light Spectra of Organic
  Molecular Crystals (COMPUTER Modeling)

abstract:
  Calculations of frequency spectra for organic molecular crystals taking
various defects in their structure into account are carried out. It is shown
how the presence of the vacancies, orientation disorder, and surface presence
affects spectra. It was found, that each defect has the characteristic set of
lines in the spectra.


title:
Calculation of Spectra of the Lattice and Surface Vibrations of Organic
  Nano-Crystals

abstract:
  Calculations of frequencies of the lattice and surface oscillations of
organic nano-crystals are carried out. As the sample the para-dichlorobenzol
has been chosen. Change of spectra of oscillations from the sizes of
nano-particles is found. It is shown that with the reduction of the sizes of
nano-particles a spectrum of the surface oscillations prevailing. Calculations
have shown that for the correct interpretation of the observational spectra it
is necessary to consider orientation disorder of the surface molecules and
presence of vacancies in nano-particle volume.


title:
Temperature Changes of Spectra of the Lattice and Surface Oscillations
  of Organic Molecular Nano-Crystals (COMPUTER Modeling)

abstract:
  Dependence of frequency spectra of the lattice oscillations of organic
nano-crystals on temperature is studied at presence of vacancies in structure.
In a frequency spectrum a number of additional lines monotonously changing with
temperature is observed. Also, the spectrum of the surface oscillations is
calculated at temperature change. At the same time, the low-frequency line has
non-linear behavior with temperature change.


title:
The interaction of planetary nebulae and their AGB progenitors with the
  interstellar medium

abstract:
  Interaction with the Interstellar Medium (ISM) cannot be ignored in
understanding planetary nebula (PN) evolution and shaping. In an effort to
understand the range of shapes observed in the outer envelopes of PNe, we have
run a comprehensive set of three-dimensional hydrodynamic simulations, from the
beginning of the asymptotic giant branch (AGB) superwind phase until the end of
the post--AGB/PN phase. A 'triple-wind' model is used, including a slow AGB
wind, fast post--AGB wind and third wind reflecting the linear movement through
the ISM. A wide range of stellar velocities, mass-loss rates and ISM densities
have been considered. We find ISM interaction strongly affects outer PN
structures, with the dominant shaping occuring during the AGB phase. The
simulations predict four stages of PN--ISM interaction whereby the PN is
initially unaffected (1), then limb-brightened in the direction of motion (2),
then distorted with the star moving away from the geometric centre (3) and
finally so distorted that the object is no longer recognisable as a PN and may
not be classed as such (4). Parsec-size shells around PN are predicted to be
common. The structure and brightness of ancient PNe is largely determined by
the ISM interaction, caused by rebrightening during the second stage; this
effect may address the current discrepancies in Galactic PN abundance. The
majority of PNe will have tail structures. Evidence for strong interaction is
found for all known planetary nebulae in globular clusters.


title: Trapped Rydberg Ions: From Spin Chains to Fast Quantum Gates

abstract:
  We study the dynamics of Rydberg ions trapped in a linear Paul trap, and
discuss the properties of ionic Rydberg states in the presence of the static
and time-dependent electric fields constituting the trap. The interactions in a
system of many ions are investigated and coupled equations of the internal
electronic states and the external oscillator modes of a linear ion chain are
derived. We show that strong dipole-dipole interactions among the ions can be
achieved by microwave dressing fields. Using low-angular momentum states with
large quantum defect the internal dynamics can be mapped onto an effective spin
model of a pair of dressed Rydberg states that describes the dynamics of
Rydberg excitations in the ion crystal. We demonstrate that excitation transfer
through the ion chain can be achieved on a nanosecond timescale and discuss the
implementation of a fast two-qubit gate in the ion chain.


title: Magnetism and superconductivity in the $t{-}t^\prime{-}J$ model

abstract:
  We present a systematic study of the phase diagram of the $t{-}t^\prime{-}J$
model by using the Green's function Monte Carlo (GFMC) technique, implemented
within the fixed-node (FN) approximation and a wave function that contains both
antiferromagnetic and d-wave pairing. This enables us to study the interplay
between these two kinds of order and compare the GFMC results with the ones
obtained by the simple variational approach. By using a generalization of the
forward-walking technique, we are able to calculate true FN ground-state
expectation values of the pair-pair correlation functions. In the case of
$t^\prime=0$, there is a large region with a coexistence of superconductivity
and antiferromagnetism, that survives up to $\delta_c \sim 0.10$ for $J/t=0.2$
and $\delta_c \sim 0.13$ for $J/t=0.4$. The presence of a finite $t^\prime/t<0$
induces a strong suppression of both magnetic (with $\delta_c \lesssim 0.03$,
for $J/t=0.2$ and $t^\prime/t=-0.2$) and pairing correlations. In particular,
the latter ones are depressed both in the low-doping regime and around $\delta
\sim 0.25$, where strong size effects are present.


title:
Joint power control and user scheduling in multicell wireless networks:
  Capacity scaling laws

abstract:
  We address the optimization of the sum rate performance in multicell
interference-limited singlehop networks where access points are allowed to
cooperate in terms of joint resource allocation. The resource allocation
policies considered here combine power control and user scheduling. Although
very promising from a conceptual point of view, the optimization of the sum of
per-link rates hinges, in principle, on tough issues such as computational
complexity and the requirement for heavy receiver-to-transmitter channel
information feedback across all network cells. In this paper, we show that, in
fact, distributed algorithms are actually obtainable in the asymptotic regime
where the numbers of users per cell is allowed to grow large. Additionally,
using extreme value theory, we provide scaling laws for upper and lower bounds
for the network capacity (sum of single user rates over all cells),
corresponding to zero-interference and worst-case interference scenarios. We
show that the scaling is either dominated by path loss statistics or by
small-scale fading, depending on the regime and user location scenario. We show
that upper and lower rate bounds behave in fact identically, asymptotically.
This remarkable result suggests not only that distributed resource allocation
is practically possible but also that the impact of multicell interference on
the capacity (in terms of scaling) actually vanishes asymptotically.


title: Regulator constants and the parity conjecture

abstract:
  The p-parity conjecture for twists of elliptic curves relates multiplicities
of Artin representations in p-infinity Selmer groups to root numbers. In this
paper we prove this conjecture for a class of such twists. For example, if E/Q
is semistable at 2 and 3, K/Q is abelian and K^\infty is its maximal pro-p
extension, then the p-parity conjecture holds for twists of E by all orthogonal
Artin representations of Gal(K^\infty/Q). We also give analogous results when
K/Q is non-abelian, the base field is not Q and E is replaced by an abelian
variety. The heart of the paper is a study of relations between permutation
representations of finite groups, their "regulator constants", and
compatibility between local root numbers and local Tamagawa numbers of abelian
varieties in such relations.


title:
Andreev bound states at a cuprate grain boundary junction: A lower bound
  for the upper critical field

abstract:
  We investigate in-plane quasiparticle tunneling across thin film grain
boundary junctions (GBJs) of the electron-doped cuprate
La$_{2-x}$Ce$_{x}$CuO$_4$ in magnetic fields up to $B=16 $T, perpendicular to
the CuO$_2$ layers. The differential conductance in the superconducting state
shows a zero bias conductance peak (ZBCP) due to zero energy surface Andreev
bound states. With increasing temperature $T$, the ZBCP vanishes at the
critical temperature $T_c\approx29 $K if B=0, and at $T=12 $K for B=16 T. As
the ZBCP is related to the macroscopic phase coherence of the superconducting
state, we argue that the disappearance of the ZBCP at a field $B_{ZBCP}(T)$
must occur below the upper critical field $B_{c2}(T)$ of the superconductor. We
find $B_{ZBCP}(0) \approx 25 $T which is at least a factor of 2.5 higher than
previous estimates of $B_{c2}(0)$.


title:
Anomaly Mediation, Fayet-Iliopoulos D-terms and the Renormalisation
  Group

abstract:
  We address renormalisation group evolution issues that arise in the Anomaly
Mediated Supersymmetry Breaking scenario when the tachyonic slepton problem is
resolved by Fayet-Iliopoulos term contributions. We present typical sparticle
spectra both for the original formulation of this idea and an alternative using
Fayet-Iliopoulos terms for a U(1) compatible with a straightforward GUT
embedding.


title: A Novel Solution to the Frenet-Serret Equations

abstract:
  A set of equations is developed to describe a curve in space given the
curvature $\kappa$ and the angle of rotation $\theta$ of the osculating plane.
The set of equations has a solution (in terms of $\kappa$ and $\theta$) that
indirectly solves the Frenet-Serret equations, with a unique value of $\theta$
for each specified value of $\tau$. Explicit solutions can be generated for
constant $\theta$. The equations break down when the tangent vector aligns to
one of the unit coordinate vectors, requiring a reorientation of the local
coordinate system.


title: Half BPS states in AdS_5 x Y^{p,q}

abstract:
  We study a class of solutions of IIB Supergravity which are asymptotically
AdS_5 x Y^{p,q}. They have an R x SO(4) x SU(2) x U(1) isometry and preserve
half of the 8 supercharges of the background geometry. They are described by a
set of second order differential equations that we have found and analysed in a
previous paper, where we studied 1/8 BPS states in the maximally supersymmetric
AdS_5 x S^5 background. These geometries correspond to certain chiral primary
operators of the N=1 superconformal quiver theories, dual to IIB theory on
AdS_5 x Y^{p,q}.
  We also show how to recover the AdS_5 x Y^{p,q} backgrounds by suitably
doubling the number of preserved supersymmetries. We then solve the
differential equations perturbatively in a large AdS_5 radius expansion,
imposing asymptotic AdS_5 x Y^{p,q} boundary conditions. We compute the global
baryonic and mesonic charges, including the R-charge. As for the computation of
the mass, i.e. the conformal dimension D of the dual field theory operators,
which is notoriously subtle in asymptotically AdS backgrounds, we adopt the
general formalism due to Wald and collaborators, which gives a finite result,
and verify the relation D=3 R / 2, demanded by the N=1 superconformal algebra.


title: Chern numbers and diffeomorphism types of projective varieties

abstract:
  In 1954 Hirzebruch asked which linear combinations of Chern numbers are
topological invariants of smooth complex projective varieties. We give a
complete answer to this question in small dimensions, and also prove partial
results without restrictions on the dimension.


title:
Millimeter-Scale, Highly Ordered Single Crystalline Graphene Grown on Ru
  (0001) Surface

abstract:
  We demonstrate a method for synthesizing large scale single layer graphene by
thermal annealing of ruthenium single crystal containing carbon. Low energy
electron diffraction indicates the graphene grows to as large as millimeter
dimensions with good long-range order, and scanning tunneling microscope shows
perfect crystallinity. Analysis of Moire pattern augmented with
first-principles calculations shows the graphene layer is incommensurate with
the underlying Ru(0001) surface forming a N by N superlattice with an average
lattice strain of ~ +0.81%. Our findings offer an effective method for
producing high quality single crystalline graphene for fundamental research and
large-scale graphene wafer for device fabrication and integration.


title: Simulation Studies and Detector Scenarios for an ILC Polarimeter

abstract:
  High energy longitudinal electron polarimetry will be based on Compton
scattering for the International Linear Collider. An unobtrusive measurement
has to include a magnet chicane setup serving as a spectrometer. Current
proposals make use of Cerenkov detectors for electron detection. A fast
simulation has been developed to study the basic properties of scenarios for
the polarimeter setup.


title: Gromov-Witten invariants of target curves via Symplectic Field Theory

abstract:
  We compute the Gromov-Witten potential at all genera of target smooth Riemann
surfaces using Symplectic Field Theory techniques and establish differential
equations for the full descendant potential. This amounts to impose (and
possibly solve) different kinds of Schroedinger equations related to some
quantization of the dispersionless KdV hierarchy. In particular we find very
explicit formulas for the Gromov-Witten invariants of low degree of P1 with
descendants of the Kaehler class.


title: Supermassive black holes from OASIS and SAURON integral-field kinematics

abstract:
  Supermassive black holes are a key element in our understanding of how
galaxies form. Most of the progress in this very active field of research is
based on just ~30 determinations of black hole mass, accumulated over the past
decade. We illustrate how integral-field spectroscopy, and in particular our
OASIS modeling effort, can help improve the current situation.


title: Electromagnetic cloaking in the visible frequency range

abstract:
  Electromagnetic metamaterials provide unprecedented freedom and flexibility
to introduce new devices, which control electromagnetic wave propagation in
very unusual ways. Very recently theoretical design of an "invisibility cloak"
has been suggested, which has been realized at microwave frequencies in a
two-dimensional cylindrical geometry. In this communication we report on the
experimental realization of the dielectric permittivity distribution required
for non-magnetic cloaking in the visible frequency range.


title: Dynamics of the Distorted Diamond Chain

abstract:
  We present results on the dynamics of the distorted diamond chain, S=1/2
dimers alternating with single spins 1/2 and exchange couplings $J_1$ and $J_3$
in between. The dynamics in the spin fluid (SF) and tetramer-dimer (TD) phases
is investigated numerically by exact diagonalisation for up to 24 spins.
Representative excitation spectra are presented, both for zero magnetic field
and in the 1/3 plateau phase and the relevant parameters are determined across
the phase diagram. The behavior across the SF-TD phase transition line is
discussed for the specific heat and for excitation spectra. The relevance of
the distorted diamond chain model for the material Cu$_3$(CO$_3$)$_2$(OH)$_2$
(azurite) is discussed with particular emphasis on inelastic neutron scattering
experiments, a recent suggestion of one possibly ferromagnetic coupling
constant is not confirmed.


title: A Complete Scheme for a Muon Collider

abstract:
  A complete scheme for production, cooling, acceleration, and ring for a 1.5
TeV center of mass muon collider is presented, together with parameters for two
higher energy machines. The schemes starts with the front end of a proposed
neutrino factory that yields bunch trains of both muon signs. Six dimensional
cooling in long-period helical lattices reduces the longitudinal emittance
until it becomes possible to merge the trains into single bunches, one of each
sign. Further cooling in all dimensions is applied to the single bunches in
further helical lattices. Final transverse cooling to the required parameters
is achieved in 50 T solenoids.


title: Renormalisation in Quantum Mechanics

abstract:
  This lecture provides an introduction to the renormalisation group as applied
to scattering of two nonrelativistic particles. As well as forming a framework
for constructing effective theories of few-nucleon systems, these ideas also
provide a simple example which illustrates general features of the
renormalisation group.


title:
Bose-Einstein condensates with attractive 1/r interaction: The case of
  self-trapping

abstract:
  Amplifying on a proposal by O'Dell et al. for the realization of
Bose-Einstein condensates of neutral atoms with attractive $1/r$ interaction,
we point out that the instance of self-trapping of the condensate, without
external trap potential, is physically best understood by introducing
appropriate "atomic" units. This reveals a remarkable scaling property: the
physics of the condensate depends only on the two parameters $N^2 a/a_u$ and
$\gamma/N^2$, where $N$ is the particle number, $a$ the scattering length,
$a_u$ the "Bohr" radius and $\gamma$ the trap frequency in atomic units. We
calculate accurate numerical results for self-trapping wave functions and
potentials, for energies, sizes and peak densities, and compare with previous
variational results. As a novel feature we point out the existence of a second
solution of the extended Gross-Pitaevskii equation for negative scattering
lengths, with and without trapping potential, which is born together with the
ground state in a tangent bifurcation. This indicates the existence of an
unstable collectively excited state of the condensate for negative scattering
lengths.


title:
Observation of opto-mechanical multistability in a high Q torsion
  balance oscillator

abstract:
  We observe the opto-mechanical multistability of a macroscopic torsion
balance oscillator. The torsion oscillator forms the moving mirror of a
hemi-spherical laser light cavity. When a laser beam is coupled into this
cavity, the radiation pressure force of the intra-cavity beam adds to the
torsion wire's restoring force, forming an opto-mechanical potential. In the
absence of optical damping, up to 23 stable trapping regions were observed due
to local light potential minima over a range of 4 micrometer oscillator
displacement. Each of these trapping positions exhibits optical spring
properties. Hysteresis behavior between neighboring trapping positions is also
observed. We discuss the prospect of observing opto-mechanical stochastic
resonance, aiming at enhancing the signal-to-noise ratio (SNR) in gravity
experiments.


title: On Galois Groups of Prime Degree Polynomials with Complex Roots

abstract:
  Let $f$ be an irreducible polynomial of prime degree $p\geq 5$ over $\QQ$,
with precisely $k$ pairs of complex roots. Using a result of Jens H\"{o}chsmann
(1999), we show that if $p\geq 4k+1$ then $\Gal(f/\QQ)$ is isomorphic to
$A_{p}$ or $S_{p}$. This improves the algorithm for computing the Galois group
of an irreducible polynomial of prime degree, introduced by A. Bialostocki and
T.Shaska.
  If such a polynomial $f$ is solvable by radicals then its Galois group is a
Frobenius group of degree p. Conversely, any Frobenius group of degree p and of
even order, can be realized as the Galois group of an irreducible polynomial of
degree $p$ over $\QQ$ having complex roots.


title: Excitation of K-shell electrons by electron impact

abstract:
  The universal scaling behavior for the electron-impact excitation cross
sections of the $2s$ states of hydrogen- and helium-like multicharged ions is
deduced. The study is performed within the framework of non-relativistic
perturbation theory, taking into account the one-photon exchange diagrams.
Special emphasis is laid on the near-threshold energy domain. The parametrical
relationship between the cross sections for excitation of multicharged ions
with different number of electrons is established.


title:
On the nature of the z=0 X-ray absorbers: I. Clues from an external
  group

abstract:
  Absorption lines of OVII at redshift zero are observed in high quality
Chandra spectra of extragalactic sightlines. The location of the absorber
producing these lines, whether from the corona of the Galaxy or from the Local
Group or even larger scale structure, has been a matter of debate. Here we
study another poor group like our Local Group to understand the distribution of
column density from galaxy to group scales. We show that we cannot yet rule out
the group origin of z=0 systems. We further argue that the debate over Galactic
vs. extragalactic origin of z=0 systems is premature as they likely contain
both components and predict that future higher resolution observations will
resolve the z=0 systems into multiple components.


title:
Photometric Redshift Requirements for Self-Calibration of Cluster Dark
  Energy Studies

abstract:
  The ability to constrain dark energy from the evolution of galaxy cluster
counts is limited by the imperfect knowledge of cluster redshifts. Ongoing and
upcoming surveys will mostly rely on redshifts estimated from broad-band
photometry (photo-z's). For a Gaussian distribution for the cluster photo-z
errors and a high cluster yield cosmology defined by the WMAP 1 year results,
the photo-z bias and scatter needs to be known better than 0.003 and 0.03,
respectively, in order not to degrade dark energy constrains by more than 10%
for a survey with specifications similar to the South Pole Telescope. Smaller
surveys and cosmologies with lower cluster yields produce weaker photo-z
requirements, though relative to worse baseline constraints. Comparable photo-z
requirements are necessary in order to employ self-calibration techniques when
solving for dark energy and observable-mass parameters simultaneously. On the
other hand, self-calibration in combination with external mass inferences helps
reduce photo-z requirements and provides important consistency checks for
future cluster surveys. In our fiducial model, training sets with spectroscopic
redshifts for ~5%-15% of the detected clusters are required in order to keep
degradations in the dark energy equation of state lower than 20%.


title:
A Macroscopic Description of Coherent Geo-Magnetic Radiation from Cosmic
  Ray Air Showers

abstract:
  We have developed a macroscopic description of coherent electro-magnetic
radiation from air showers initiated by ultra-high energy cosmic rays due to
the presence of the geo-magnetic field. This description offers a simple and
direct insight in the relation between the properties of the air shower and the
time-structure of the radio pulse.


title:
Excitation and photoionization processes involving the bound $ns$
  electrons

abstract:
  We have considered the processes of excitation and ionization of light
multicharged ions by impact of high-energy particles, which proceed with
participation of the $ns$ electrons. The screening corrections to the energy
levels and photoionization cross sections are evaluated analytically within the
framework of the non-relativistic perturbation theory with respect to the
electron-electron interaction. The universal scalings for the excitation and
ionization cross sections are studied for arbitrary principal quantum numbers
$n$.


title:
New Insights into Traffic Dynamics: A Weighted Probabilistic Cellular
  Automaton Model

abstract:
  From the macroscopic viewpoint for describing the acceleration behavior of
drivers, this letter presents a weighted probabilistic cellular automaton model
(the WP model, for short) by introducing a kind of random acceleration
probabilistic distribution function. The fundamental diagrams, the
spatio-temporal pattern are analyzed in detail. It is shown that the presented
model leads to the results consistent with the empirical data rather well,
nonlinear velocity-density relationship exists in lower density region, and a
new kind of traffic phenomenon called neo-synchronized flow is resulted.
Furthermore, we give the criterion for distinguishing the high-speed and
low-speed neo-synchronized flows and clarify the mechanism of this kind of
traffic phenomena. In addition, the result that the time evolution of
distribution of headways is displayed as a normal distribution further
validates the reasonability of the neo-synchronized flow. These findings
suggest that the diversity and randomicity of drivers and vehicles has indeed
remarkable effect on traffic dynamics.


title:
Theoretical coarse-graining approach to bridge length scales in diblock
  copolymer liquids

abstract:
  A microscopic theory for coarse graining diblock copolymers into dumbbells of
interacting soft colloidal particles has been developed, based on the solution
of liquid-state integral equations. The Ornstein-Zernike equation is solved to
provide a mesoscopic description of the diblock copolymer system at the level
of block centers of mass, and at the level of polymer centers of mass.
Analytical forms of the total correlation functions for block-block,
block-monomer, and center-of-mass pairs are obtained for a liquid of
structurally symmetric diblock copolymers as a function of temperature,
density, chain length, and chain composition. The theory correctly predicts
thermodynamically-driven segregation of diblocks into microdomains as a
function of temperature ($chi$ parameter). The coarse-grained description
contains contributions from density and concentration fluctuations, with the
latter becoming dominant as temperature decreases. Numerical calculations for
the block coarse-grained total correlation functions, as a function of the
proximity of the system to its phase transition, are presented. Comparison with
united atom molecular dynamics simulations are carried out in the athermal
regime, where simulations and theory quantitatively agree with no need of
adjustable parameters.


title:
The static potential in {\cal N}=4 supersymmetric Yang-Mills at weak
  coupling

abstract:
  We compute the static potential associated to the locally 1/2 BPS Wilson loop
in ${\cal N}$=4 supersymmetric Yang-Mills theory with ${\cal O}(\lambda^2/r)$
accuracy. We also resum the leading logarithms, of ${\cal
O}(\lambda^{n+1}\ln^n\lambda/r)$, and show the structure of the renormalization
group equation at next-to-leading order in the multipole expansion. In order to
obtain these results it is crucial the use of an effective theory for the
ultrasoft degrees of freedom. We develop this theory up to next-to-leading
order in the multipole expansion. Using the same formalism we also compute the
leading logarithms, of ${\cal O}(\lambda^{n+3}\ln^n\lambda/r)$, of the static
potential associated to an ordinary Wilson loop in the same theory.