title:
Very high energy gamma-ray observations of the galaxy clusters Abell 496
  and Abell 85 with H.E.S.S

abstract:
  Aims: The nearby galaxy clusters Abell 496 and Abell 85 are studied in the
very high energy (VHE, E > 100 GeV) band to investigate VHE cosmic rays (CRs)
in this class of objects which are the largest gravitationally bound systems in
the Universe. Methods: H.E.S.S., an array of four Imaging Atmospheric Cherenkov
Telescopes (IACT), is used to observe the targets in the range of VHE gamma
rays. Results: No significant gamma-ray signal is found at the respective
position of the two clusters with several different source size assumptions for
each target. In particular, emission regions corresponding to the high density
core, to the extension of the entire X-ray emission in these clusters, and to
the very extended region where the accretion shock is expected, are
investigated. Upper limits are derived for the gamma-ray flux at energies E>570
GeV for Abell 496 and E>460 GeV for Abell 85. Conclusions: From the
non-detection in VHE gamma rays, upper limits on the total energy of hadronic
CRs in the clusters are calculated. If the cosmic-ray energy density follows
the large scale gas density profile, the limit on the fraction of energy in
these non-thermal particles with respect to the total thermal energy of the
intra-cluster medium (ICM) is 51% for Abell 496 and only 8% for Abell 85 due to
its larger mass and higher gas density. These upper limits are compared with
theoretical estimates. They predict about ~10% of the thermal energy of the ICM
in non-thermal particles. The observations presented here can constrain these
predictions especially for the case of the Abell 85 cluster.


title: Large deviations for intersection local times in critical dimension

abstract:
  Let $(X_t,t\geq0)$ be a continuous time simple random walk on $\mathbb{Z}^d$
($d\geq3$), and let $l_T(x)$ be the time spent by $(X_t,t\geq0)$ on the site
$x$ up to time $T$. We prove a large deviations principle for the $q$-fold
self-intersection local time $I_T=\sum_{x\in\mathbb{Z}^d}l_T(x)^q$ in the
critical case $q=\frac{d}{d-2}$. When $q$ is integer, we obtain similar results
for the intersection local times of $q$ independent simple random walks.


title: From gauge anomalies to gerbes and gerbal actions

abstract:
  The purpose of this contribution is to point out connections between recent
ideas about gerbes and gerbal actions (as higher categorical extension of
representation theory) and old discussion in quantum field theory on commutator
anomalies, gauge group extensions, and 3-cocycles. The unifying concept is the
classical obstruction theory for group extensions as explained in the reference
[ML].


title: On asymptotic dimension and a property of Nagata

abstract:
  In this note we prove that every metric space $(X, d)$ of asymptotic
dimmension at most $n$ is coarsely equivalent to a metric space $(Y, D)$ that
satisfies the following property of Nagata:
  For every $n+2$ points $y_1,..., y_{n+2}$ in $Y$ and for every $x$ in $Y$
there exist two different $i,j$ such that $D(y_i,y_j)\le D(x,y_i)$.
  This solves problem 1400 of the book Open problems in Topology II.


title: Non-minimal Einstein-Yang-Mills-dilaton theory

abstract:
  We establish a new non-minimal Einstein-Yang-Mills-dilaton model, for which
the Lagrangian is linear in the curvature and contains eight arbitrary
functions of the scalar (dilaton) field. The self-consistent system of
equations for the non-minimally coupled gauge, scalar and gravitational fields
is derived. As an example of an application we discuss the model with pp-wave
symmetry. Two exact explicit regular solutions of the whole system of master
equations, belonging to the class of pp-wave solutions, are presented.


title: The Top Quark Decay Vertex in Standard Model Extensions

abstract:
  New physics interactions can affect the strength and structure of the $tbW$
vertex. We investigate the magnitudes and phases of "anomalous" contributions
to this vertex in a two-Higgs doublet and the minimal supersymmetric extension
of the standard model, and in a top-color assisted technicolor (TC2) model.
While the magnitudes of the anomalous couplings remain below 1 percent in the
first two models, TC2 interactions can reduce the left-chiral coupling $f_L$ by
several percent.


title:
Evolution of Massive Scalar Fields in the Spacetime of a Tense Brane
  Black Hole

abstract:
  In the spacetime of a $d$-dimensional static tense brane black hole we
elaborate the mechanism by which massive scalar fields decay. The metric of a
six-dimensional black hole pierced by a topological defect is especially
interesting. It corresponds to a black hole residing on a tensional 3-brane
embedded in a six-dimensional spacetime, and this solution has gained
importance due to the planned accelerator experiments. It happened that the
intermediate asymptotic behaviour of the fields in question was determined by
an oscillatory inverse power-law. We confirm our investigations by numerical
calculations for five- and six-dimensional cases. It turned out that the
greater the brane tension is, the faster massive scalar fields decay in the
considered spacetimes.


title:
Gravitational collapse and the formation of black holes for the
  spherically symmetric Einstein-Vlasov system

abstract:
  We review results on the spherically symmetric, asymptotically flat
Einstein-Vlasov system. We focus on a recent result where we found explicit
conditions on the initial data which guarantee the formation of a black hole in
the evolution. Among these data there are data such that the corresponding
solutions exist globally in Schwarzschild coordinates. We put these results
into a more general context, and we include arguments which show that the
spacetimes we obtain satisfy the weak cosmic censorship conjecture and contain
a black hole in the sense of suitable mathematical definitions of these
concepts which are available in the literature.


title: The nonlinear N-membranes evolution problem

abstract:
  The parabolic N-membranes problem for the p-Laplacian and the complete order
constraint on the components of the solution is studied in what concerns the
approximation, the regularity and the stability of the variational solutions.
We extend to the evolutionary case the characterization of the Lagrange
multipliers associated with the ordering constraint in terms of the
characteristic functions of the coincidence sets. We give continuous dependence
results, and study the asymptotic behavior as $t \to \infty$ of the solution
and the coincidence sets, showing that they converge to their stationary
counterparts.


title: Polyomino-Based Digital Halftoning

abstract:
  In this work, we present a new method for generating a threshold structure.
This kind of structure can be advantageously used in various halftoning
algorithms such as clustered-dot or dispersed-dot dithering, error diffusion
with threshold modulation, etc. The proposed method is based on rectifiable
polyominoes -- a non-periodic hierarchical structure, which tiles the Euclidean
plane with no gaps. Each polyomino contains a fixed number of discrete
threshold values. Thanks to its inherent non-periodic nature combined with
off-line optimization of threshold values, our polyomino-based threshold
structure shows blue-noise spectral properties. The halftone images produced
with this threshold structure have high visual quality. Although the proposed
method is general, and can be applied on any polyomino tiling, we consider one
particular case: tiling with G-hexominoes. We compare our polyomino-based
threshold structure with the best known state-of-the-art methods for generation
threshold matrices, and conclude considerable improvement achieved with our
method.


title: Statistical properties of time-reversible triangular maps of the square

abstract:
  Time reversal symmetric triangular maps of the unit square are introduced
with the property that the time evolution of one of their two variables is
determined by a piecewise expanding map of the unit interval. We study their
statistical properties and establish the conditions under which their
equilibrium measures have a product structure, i.e. factorises in a symmetric
form. When these conditions are not verified, the equilibrium measure does not
have a product form and therefore provides additional information on the
statistical properties of theses maps. This is the case of anti-symmetric cusp
maps, which have an intermittent fixed point and yet have uniform invariant
measures on the unit interval. We construct the invariant density of the
corresponding two-dimensional triangular map and prove that it exhibits a
singularity at the intermittent fixed point.


title:
PIC simulation of a strong double layer in a nonrelativistic plasma
  flow: Electron acceleration to ultrarelativistic speeds

abstract:
  Two charge- and current neutral plasma beams are modelled with a
one-dimensional PIC simulation. The beams are uniform and unbounded. The
relative speed between both beams is 0.4c. One beam is composed of electrons
and protons and one out of protons and negatively charged oxygen (dust). All
species have the temperature 9 keV. A Buneman instability develops between the
electrons of the first beam and the protons of the second beam. The wave traps
the electrons, which form plasmons. The plasmons couple energy into the ion
acoustic waves, which trap the protons of the second beam. A proton phase space
hole grows, which develops through its interaction with the oxygen and the
heated electrons into a rarefaction pulse. This pulse drives a strong ion
acoustic double layer, which accelerates a beam of electrons to about 50 MeV,
which is comparable to the proton kinetic energy. The proton distribution
eventually evolves into an electrostatic shock. Beams of charged particles
moving at such speeds may occur in the foreshock of supernova remnant shocks.
This double layer is thus potentially relevant for the electron acceleration
(injection) into the diffusive shock acceleration by supernova remnants shocks.


title:
An analysis of electron distributions in galaxy clusters by means of the
  flux ratio of iron lines FeXXV and XXVI

abstract:
  The interpretation of hard X-ray emission from galaxy clusters is still
ambiguous and different models proposed can be probed using various
observational methods. Here we explore a new method based on Fe line
observations.
  Spectral line emissivities have usually been calculated for a Maxwellian
electron distribution. In this paper a generalized approach to calculate the
iron line flux for a modified Maxwellian distribution is considered.
  We have calculated the flux ratio of iron lines for the various possible
populations of electrons that have been proposed to account for measurements of
hard X-ray excess emission from the clusters A2199 and Coma. We found that the
influence of the suprathermal electron population on the flux ratio is more
prominent in low temperature clusters (as Abell 2199) than in high temperature
clusters (as Coma).


title:
3-Sasakian manifolds in dimension seven, their spinors and G_2
  structures

abstract:
  It is well-known that 7-dimensional 3-Sasakian manifolds carry a
one-parametric family of compatible G_2 structures and that they do not admit a
characteristic connection. In this note, we show that there is nevertheless a
distinguished cocalibrated G_2 structure in this family whose characteristic
connection along with its parallel spinor field can be used for a thorough
investigation of the geometric properties of 7-dimensional 3-Sasakian
manifolds. Many known and some new properties can be easily derived from the
properties of this connection and the spinor field, yielding thus an
appropriate substitute for the missing characteristic connection.


title: The XMM-Newton view of AGN with intermediate mass black holes

abstract:
  We have observed with XMM-Newton four radiatively efficient active type 1
galaxies with black hole masses < 10^6 Msun, selected optically from the SDSS.
We show here that their soft X-ray spectrum exhibits a soft excess with the
same characteristics as that observed ubiquitously in radio-quiet Seyfert 1
galaxies and type 1 quasars, both in terms of temperatures and strength.
However, even when the soft X-ray excess is modelled with a pure thermal disc,
its luminosity turns out to be much lower than that expected from accretion
theory for the given temperature, casting further doubts on a thermal
interpretation for soft excesses. While alternative scenarios for the nature of
the soft excess (namely smeared ionized absorption and disc reflection) cannot
be distinguished on a pure statistical basis, we point out that the absorption
model produces a strong correlation between absorbing column density and
ionization state, which may be difficult to interpret and is most likely
spurious. As for reflection, it does only invoke standard ingredients of any
accretion model for radiatively efficient sources such as a hard X-rays source
and a relatively cold (though partially ionized) accretion disc, and therefore
seems the natural choice to explain the soft excess in most (if not all) cases.
The reflection model is also consistent with the additional presence of a
thermal disc component with the theoretically expected temperature (although,
again, with smaller-than-expected total luminosity). The observed active
galaxies are among the most variable in X-rays and their excess variance is
among the largest. This is in line with their relatively small black hole mass
and with expectations from simple power spectra models. (abridged)


title: Multiple Resonances in Fluid-Loaded Vibrating Structures

abstract:
  This study deals with vibroacoustics under heavy fluid loading conditions.
Considerable attention has been and remains focused on this subject not only
because industry is very concerned but also because of mathematical
difficulties that make the numerical resolution of the problem very difficult.
It was recently observed in a numerical study on a high order perturbation
method under heavy fluid loading that a loaded vibrating plate results in a
frequency shift of the in vacuo single resonance (in both the real part because
of the fluid added mass and the imaginary part because of energy lost by
radiation into the fluid) as well as increase in the number of the resonance
frequencies : as a result of the loading, each single in vacuo resonance
frequency of the structure is transformed into a multiple resonance frequency.
Here we show that this phenomenon is said to be an extension to the heavy
loading condition of the Sanchez's classical result that have established that
in the case of a light loading conditions "the scattering frequencies of a
fluid loaded elastic structure (ie the resonance frequencies) are nearly the
real eigenfrequencies of the elastic body alone and the complex scattering
frequencies of the fluid with a rigid solid". Using classical results in the
framework of the theory of entire functions, it is established that a single
resonance of a simply supported fluid loaded rectangular plate is transformed
into an infinite number of resonances.


title:
Multifractal analysis with the probability density function at the
  three-dimensional Anderson transition

abstract:
  The probability density function (PDF) for critical wavefunction amplitudes
is studied in the three-dimensional Anderson model. We present a formal
expression between the PDF and the multifractal spectrum f(alpha) in which the
role of finite-size corrections is properly analyzed. We show the non-gaussian
nature and the existence of a symmetry relation in the PDF. From the PDF, we
extract information about f(alpha) at criticality such as the presence of
negative fractal dimensions and we comment on the possible existence of
termination points. A PDF-based multifractal analysis is hence shown to be a
valid alternative to the standard approach based on the scaling of general
inverse participation ratios.


title: Polymorphic evolution sequence and evolutionary branching

abstract:
  We are interested in the study of models describing the evolution of a
polymorphic population with mutation and selection in the specific scales of
the biological framework of adaptive dynamics. The population size is assumed
to be large and the mutation rate small. We prove that under a good combination
of these two scales, the population process is approximated in the long time
scale of mutations by a Markov pure jump process describing the successive
trait equilibria of the population. This process, which generalizes the
so-called trait substitution sequence, is called polymorphic evolution
sequence. Then we introduce a scaling of the size of mutations and we study the
polymorphic evolution sequence in the limit of small mutations. From this study
in the neighborhood of evolutionary singularities, we obtain a full
mathematical justification of a heuristic criterion for the phenomenon of
evolutionary branching. To this end we finely analyze the asymptotic behavior
of 3-dimensional competitive Lotka-Volterra systems.


title:
Combining chromosomal arm status and significantly aberrant genomic
  locations reveals new cancer subtypes

abstract:
  Many types of tumors exhibit chromosomal losses or gains, as well as local
amplifications and deletions. Within any given tumor type, sample specific
amplifications and deletionsare also observed. Typically, a region that is
aberrant in more tumors,or whose copy number change is stronger, would be
considered as a more promising candidate to be biologically relevant to cancer.
We sought for an intuitive method to define such aberrations and prioritize
them. We define V, the volume associated with an aberration, as the product of
three factors: a. fraction of patients with the aberration, b. the aberrations
length and c. its amplitude. Our algorithm compares the values of V derived
from real data to a null distribution obtained by permutations, and yields the
statistical significance, p value, of the measured value of V. We detected
genetic locations that were significantly aberrant and combined them with
chromosomal arm status to create a succint fingerprint of the tumor genome.
This genomic fingerprint is used to visualize the tumors, highlighting events
that are co ocurring or mutually exclusive. We allpy the method on three
different public array CGH datasets of Medulloblastoma and Neuroblastoma, and
demonstrate its ability to detect chromosomal regions that were known to be
altered in the tested cancer types, as well as to suggest new genomic locations
to be tested. We identified a potential new subtype of Medulloblastoma, which
is analogous to Neuroblastoma type 1.


title: Cosmology and the Noncommutative approach to the Standard Model

abstract:
  We study cosmological consequences of the noncommutative approach to the
standard model. Neglecting the nonminimal coupling of the Higgs field to the
curvature, noncommutative corrections to Einstein's equations are present only
for inhomogeneous and anisotropic space-times. Considering the nominimal
coupling however, we obtain corrections even for background cosmologies. A link
with dilatonic gravity as well as chameleon cosmology are briefly discussed,
and potential experimental consequences are mentioned.

categories: hep-th astro-ph gr-qc hep-ph math-ph math.MP


title:
Effects of Spatial Dispersion on Reflection from Mushroom-type
  Artificial Impedance Surfaces

abstract:
  Several recent works have emphasized the role of spatial dispersion in wire
media, and demonstrated that arrays of parallel metallic wires may behave very
differently from a uniaxial local material with negative permittivity. Here, we
investigate using local and non-local homogenization methods the effect of
spatial dispersion on reflection from the mushroom structure introduced by
Sievenpiper. The objective of the paper is to clarify the role of spatial
dispersion in the mushroom structure and demonstrate that under some conditions
it is suppressed. The metamaterial substrate, or metasurface, is modeled as a
wire medium covered with an impedance surface. Surprisingly, it is found that
in such configuration the effects of spatial dispersion may be nearly
suppressed when the slab is electrically thin, and that the wire medium can be
modeled very accurately using a local model. This result paves the way for the
design of artificial surfaces that exploit the plasmonic-type response of the
wire medium slab.


title: Transport diffusion coefficient for a Knudsen gas in a random tube

abstract:
  We consider transport diffusion in a stochastic billiard in a random tube
which is elongated in the direction of the first coordinate (the tube axis).
Inside the random tube, which is stationary and ergodic, non-interacting
particles move straight with constant speed. Upon hitting the tube walls, they
are reflected randomly, according to the cosine law: the density of the
outgoing direction is proportional to the cosine of the angle between this
direction and the normal vector. Steady state transport is studied by
introducing an open tube segment as follows: We cut out a large finite segment
of the tube with segment boundaries perpendicular to the tube axis. Particles
which leave this piece through the segment boundaries disappear from the
system. Through stationary injection of particles at one boundary of the
segment a steady state with non-vanishing stationary particle current is
maintained. We prove (i) that in the thermodynamic limit of an infinite open
piece the coarse-grained density profile inside the segment is linear, and (ii)
that the transport diffusion coefficient obtained from the ratio of stationary
current and effective boundary density gradient equals the diffusion
coefficient of a tagged particle in an infinite tube. Thus we prove Fick's law
and equality of transport diffusion and self-diffusion coefficients for quite
generic rough (random) tubes.


title: A Novel Method of Solution for the Fluid Loaded Plate

abstract:
  We study the Cauchy problem associated with the equations governing a fluid
loaded plate formulated on either the line or the half-line. We show that in
both cases the problem can be solved by employing the unified approach to
boundary value problems introduced by on of the authors in the late 1990s. The
problem on the full line was analysed by Crighton et. al. using a combination
of Laplace and Fourier transforms. The new approach avoids the technical
difficulty of the a priori assumption that the amplitude of the plate is in
$L^1_{dt}(R^+)$ and furthermore yields a simpler solution representation which
immediately implies the problem is well-posed. For the problem on the
half-line, a similar analysis yields a solution representation, but this
formula involves two unknown functions. The main difficulty with the half-line
problem is the characterisation of these two functions. By employing the
so-called global relation, we show that the two functions can be obtained via
the solution of a complex valued integral equation of the convolution type.
This equation can be solved in closed form using the Laplace transform. By
prescribing the initial data $\eta_0$ to be in $H^3(R^+)$, we show that the
solution depends continuously on the initial data, and hence, the problem is
well-posed.


title: Homology of graded Hecke algebras

abstract:
  Let H be a graded Hecke algebra with complex deformation parameters and Weyl
group W. We show that the Hochschild, cyclic and periodic cyclic homologies of
H are all independent of the parameters, and compute them explicitly. We use
this to prove that, if the deformation parameters are real, the collection of
irreducible tempered H-modules with real central character forms a Q-basis of
the representation ring of W.
  Our method involves a new interpretation of the periodic cyclic homology of
finite type algebras, in terms of the cohomology of a sheaf over the underlying
complex affine variety.


title: Resolving the jet in Cygnus A

abstract:
  Our previous studies revealed a good kinematic model for the jet of Cygnus A,
but the counter-jet speed is still not well constrained. The central engine and
part of the counter-jet of Cyg A are likely to be obscured by free-free
absorbing material, presumably a thick torus. At mm-wavelengths, the absorber
becomes optically thin, which provides a more detailed view into the inner
nuclear region. Knowing the speed of jet and counter-jet and their flux density
ratio allows to determine the jet Lorentz factors and orientation. Therefore we
started to monitor Cyg A with global VLBI at 43GHz in Oct. 2007. Our first
epoch reveals a previously unseen gap between both jets. This could be either a
sign for a new counter-jet component that is slowly separating or we start to
see the very inner acceleration region of the jet which is not efficiently
radiating at radio wavelengths. Further more the image shows transversely
resolved jet structures at distances beyond ~0.5pc which facilitate more
detailed investigations addressing jet stratification. Analysis of the resolved
jet structure shows that the initially wide jet (opening angle ~10deg)
collimates within the first parsec into a edge-brightened jet with an opening
angle of ~3deg.


title:
Angular momentum transport in a multicomponent solar wind with
  differentially flowing, thermally anisotropic ions

abstract:
  The Helios measurements of the angular momentum flux $L$ for the fast solar
wind show that the individual ion contributions, $L_p$ and $L_\alpha$, tend to
be negative (i.e., in the sense of counter-rotation with the Sun). However, the
opposite holds for the slow wind, and the overall particle contribution $L_P =
L_p + L_\alpha$ tends to exceed the magnetic one $L_M$. These aspects are at
variance with previous models. We examine whether introducing realistic ion
temperature anisotropies can resolve this discrepancy. From the general
multifluid transport equations with gyrotropic species pressure tensors, we
derive the equations governing both the meridional and azimuthal dynamics of
general axisymmetrical, rotating stellar winds that include two major ion
species. The azimuthal dynamics are examined in detail, using the empirically
constructed meridional flow profiles for the solar wind. We find that $L$ is
determined by requiring that the solution to the total angular momentum
conservation law is unique and smooth close to the Alfven point, where the
combined Alfvenic Mach number $M_T=1$. Introducing realistic ion temperature
anisotropies may introduce a change of up to 10% in $L$ and up to 1.8 km/s in
azimuthal speeds of individual ions between 0.3 and 1 AU, compared with the
isotropic case. The latter has strong consequences on the relative importance
of $L_P$ and $L_M$. However, introducing ion temperature anisotropies cannot
resolve the discrepancy between measurements and models. For the fast-wind
solutions, while in extreme cases $L_P$ becomes negative, $L_p$ never does. On
the other hand, for the slow-wind solutions, $L_P$ never exceeds $L_M$, even
though $L_M$ may be less than the individual ion contribution, since $L_p$ and
$L_\alpha$ always have opposite signs for the slow and fast wind alike.


title: Supermartingale Deomposition with General Index Set

abstract:
  We prove results on the existence of Dol\'{e}ans-Dade measures and of the
Doob-Meyer decomposition for supermartingales indexed by a general index set


title: Delta-baryon mass in a covariant Faddeev approach

abstract:
  We present a calculation of the three-quark core contribution to the mass of
the Delta-baryon in a Poincare-covariant Faddeev framework. A consistent setup
for the dressed-quark propagator, the quark-quark and quark-diquark
interactions is used, where all the ingredients are solutions of their
respective Dyson-Schwinger or Bethe-Salpeter equations in rainbow-ladder
truncation. We discuss the evolution of the Delta mass with the current-quark
mass and compare to the previously obtained mass of the nucleon.


title:
Bulk spacetimes for cosmological braneworlds with a time--dependent
  extra dimension

abstract:
  We explore the possibilities of constructing bulk spacetimes in five
dimensions for warped braneworld models with a spatially flat
Friedmann-Robertson-Walker (FRW) line element on the 3-brane and with a
time-dependent extra dimension. Our first step in this direction involves
looking at the status of energy conditions when such a bulk line element is
assumed. We check these conditions by analysing the relevant inequalities, for
specific functional forms (chosen to satisfy certain desirable features) of the
warp factor, the cosmological scale factor and the extra-dimensional scale
factor. Subsequently, we aim at obtaining solutions with different types of
bulk matter sources. We begin with a general analysis of the solution space of
non-singular Randall-Sundrum type bulk models with an exponential warp factor
and a chosen equation of state. Thereafter, we focus on three specific bulk
sources -- the ordinary scalar field, the Brans-Dicke scalar and the dilaton.
In each case, we are able to solve the field equations and obtain desirable
solutions for which, we once again check the viability of the energy
conditions. We also show how one can place branes in the bulk using the
junction conditions. The issue of resolution of the bulk singularities which
appear in our solutions, using standard methods, is also presented briefly. In
summary, we are able to demonstrate, that it is indeed possible to construct
viable bulk spacetimes for warped cosmological braneworlds with a time-varying
extra dimension and with bulk matter satisfying the energy conditions.


title:
Modelling solar-like variability for the detection of Earth-like
  planetary transits. II) Performance of the three-spot modelling, harmonic
  function fitting, iterative non-linear filtering and sliding boxcar filtering

abstract:
  We present a comparison of four methods of filtering solar-like variability
to increase the efficiency of detection of Earth-like planetary transits by
means of box-shaped transit finder algorithms. Two of these filtering methods
are the harmonic fitting method and the iterative non-linear filter that,
coupled respectively with the Box Least-Square (BLS) and Box Maximum-Likelihood
algorithms, demonstrated the best performance during the first detection blind
test organized inside the CoRoT consortium. The third method, the 3-spot model,
is a simplified physical model of Sun-like variability and the fourth is a
simple sliding boxcar filter. We apply a Monte Carlo approach by simulating a
large number of 150-day light curves (as for CoRoT long runs) for different
planetary radii, orbital periods, epochs of the first transit and standard
deviations of the photon shot noise. Stellar variability is given by the Total
Solar Irradiance variations as observed close to the maximum of solar cycle 23.
After filtering solar variability, transits are searched for by means of the
BLS algorithm. We find that the iterative non-linear filter is the best method
to filter light curves of solar-like stars when a suitable window can be
chosen. As the performance of this filter depends critically on the length of
its window, we point out that the window must be as long as possible, according
to the magnetic activity level of the star. We show an automatic method to
choose the extension of the filter window from the power spectrum of the light
curves. The iterative non-linear filter, when used with a suitable choice of
its window, has a better performance than more complicated and computationally
intensive methods of fitting solar-like variability, like the 200-harmonic
fitting or the 3-spot model.


title:
A HST/WFPC2 survey of bright young clusters in M31. I. VdB0, a massive
  star cluster seen at ~= 25 Myr

abstract:
  {Aims.} We introduce our imaging survey of possible young massive globular
clusters in M31 performed with the Wide Field and Planetary Camera 2 (WFPC2) on
the Hubble Space Telescope (HST). We present here details of the data reduction
pipeline that is being applied to all the survey data and describe its
application to the brightest among our targets, van den Bergh 0 (VdB0), taken
as a test case. {Methods.} The reddening, the age and the metallicity of the
cluster are estimated by comparison of the observed Color Magnitude Diagram
(CMD) with theoretical isochrones. {Results.} Under the most conservative
assumptions the stellar mass of VdB0 is M > 2.4 x 10^4 M_sun, but our best
estimates lie in the range ~ 4-9 x 10^4 M_sun. The CMD of VdB0 is best
reproduced by models having solar metallicity and age = 25 Myr. Ages smaller
than = 12 Myr and larger than = 60 Myr are clearly ruled out by the available
data. The cluster has a remarkable number of Red Super Giants (> 18) and a CMD
very similar to Large Magellanic Cloud clusters usually classified as young
globulars such as NGC 1850, for example. {Conclusions.} VdB0 is significantly
brighter (>~ 1 mag) than Galactic open clusters of similar age. Its present-day
mass and half-light radius (r_h=7.4 pc) are more typical of faint globular
clusters than of open clusters. However, given its position within the disk of
M31 it is expected to be destroyed by dynamical effects, in particular by
encounters with giant molecular clouds, within the next ~ 4 Gyr.


title:
Effect of quantization of vibrations on the structural properties of
  crystals

abstract:
  We study the structural effects produced by the quantization of vibrational
degrees of freedom in periodic crystals at zero temperature. To this end we
introduce a methodology based on mapping a suitable subspace of the vibrational
manifold and solving the Schroedinger equation in it. A number of increasingly
accurate approximations ranging from the quasi-harmonic approximation (QHA) to
the vibrational self-consistent field (VSCF) method and the exact solution are
described. A thorough analysis of the approximations is presented for model
monoatomic and hydrogen-bonded chains, and results are presented for a linear
HF chain where the potential energy surface is obtained via first-principles
electronic structure calculations. We focus on quantum nuclear effects on the
lattice constant, and show that the VSCF is an excellent approximation, meaning
that correlation between modes is not extremely important. The QHA is excellent
for covalently-bonded, mildly anharmonic systems, but it fails for
hydrogen-bonded ones. In the latter, the zero-point energy exhibits a
non-analytic behavior at the lattice constant where the H-atoms center, which
leads to a spurious secondary minimum in the quantum-corrected energy curve. An
inexpensive anharmonic appoximation of non-interacting modes appears to produce
rather good results for hydrogen-bonded chains, for small system sizes.
However, it converges to the incorrect QHA results for increasing size. Isotope
effects are studied for the first-principles HF chain. We show how the lattice
constant and the HF distance increase with decreasing mass, and how the QHA
proves to be insufficient to reproduce this behavior.


title:
Insular superconductivity in Co-doped iron pnictide
  CaFe$_{1-x}$Co$_x$AsF

abstract:
  The presence of macroscopic phase separation between the superconducting and
magnetic phases in \cfcaf is demonstrated by muon spin rotation (muSR)
measurements conducted across their phase boundaries (x=0.05-0.15). The
magnetic phase tends to retain the high transition temperature (T_m > T_c),
while Co-doping induces strong randomness. The volumetric fraction of
superconducting phase is nearly proportional to the Co content $x$ with
constant superfluid density. These observations suggest the formation of
superconducting "islands" (or domains) associated with Co ions in the
Fe$_2$As$_2$ layers, indicating a very short coherence length.


title: Groups of quasi-invariance and the Pontryagin duality

abstract:
  A Polish group $G$ is called a group of quasi-invariance or a QI-group, if
there exist a locally compact group $X$ and a probability measure $\mu$ on $X$
such that 1) there exists a continuous monomorphism of $G$ to $X$, and 2) for
each $g\in X$ either $g\in G$ and the shift $\mu_g$ is equivalent to $\mu$ or
$g\not\in G$ and $\mu_g$ is orthogonal to $\mu$. It is proved that $G$ is a
$\sigma$-compact subset of $X$. We show that there exists a quotient group
$\mathbb{T}^H_2$ of $\ell^2$ modulo a discrete subgroup which is a Polish
monothetic non locally quasi-convex (and hence nonreflexive) pathwise connected
QI-group, and such that the bidual of $\mathbb{T}^H_2$ is not a QI-group. It is
proved also that the bidual group of a QI-group may be not a saturated subgroup
of $X$.


title:
Constraining Cosmological Parameters with Observational Data Including
  Weak Lensing Effects

abstract:
  In this paper, we study the cosmological implications of the 100 square
degree Weak Lensing survey (the CFHTLS-Wide, RCS, VIRMOS-DESCART and GaBoDS
surveys). We combine these weak lensing data with the cosmic microwave
background (CMB) measurements from the WMAP5, BOOMERanG, CBI, VSA, ACBAR, the
SDSS LRG matter power spectrum and the Type Ia Supernoave (SNIa) data with the
"Union" compilation (307 sample), using the Markov Chain Monte Carlo method to
determine the cosmological parameters. Our results show that the \Lambda CDM
model remains a good fit to all of these data. For the dynamical dark energy
model with time evolving EoS parameterized as w_{\DE}(a) = w_0 + w_a (1-a), we
find that the best-fit model implying the mildly preference of Quintom model
whose EoS gets across the cosmological constant boundary during evolution.
Regarding the total neutrino mass limit, we obtain the upper limit, \sum
m_{\nu}< 0.471 eV (95% C.L.) within the framework of the flat \Lambda CDM
model. Due to the obvious degeneracies between the neutrino mass and the EoS of
dark energy model, this upper limit will be relaxed by a factor of 2 in the
framework of dynamical dark energy models. For the constraints on the inflation
parameters, we find that the upper limit on the ratio of the tensor to scalar
is r<0.35 (95% C.L.) and the inflationary models with the slope n_s\geq1 are
excluded at more than 2 \sigma confidence level. In this paper we pay
particular attention to the contribution from the weak lensing data and find
that the current weak lensing data do improve the constraints on matter density
\Omega_m, \sigma_8, \sum{m_{\nu}}, and the EoS of dark energy.


title:
Categorified central extensions, \'etale Lie 2-groups and Lie's Third
  Theorem for locally exponential Lie algebras

abstract:
  Lie's Third Theorem, asserting that each finite-dimensional Lie algebra is
the Lie algebra of a Lie group, fails in infinite dimensions. The modern
account on this phenomenon is the integration problem for central extensions of
infinite-dimensional Lie algebras, which in turn is phrased in terms of an
integration procedure for Lie algebra cocycles.
  This paper remedies the obstructions for integrating cocycles and central
extensions from Lie algebras to Lie groups by generalising the integrating
objects. Those objects obey the maximal coherence that one can expect.
Moreover, we show that they are the universal ones for the integration problem.
  The main application of this result is that a Mackey-complete locally
exponential Lie algebra (e.g., a Banach-Lie algebra) integrates to a Lie
2-group in the sense that there is a natural Lie functor from certain Lie
2-groups to Lie algebras, sending the integrating Lie 2-group to an isomorphic
Lie algebra.


title: Monadic approach to Galois descent and cohomology

abstract:
  We describe a simplified categorical approach to Galois descent theory. It is
well known that Galois descent is a special case of Grothendieck descent, and
that under mild additional conditions the category of Grothendieck descent data
coincides with the Eilenberg-Moore category of algebras over a suitable monad.
This also suggests using monads directly, and our monadic approach to Galois
descent makes no reference to Grothendieck descent theory at all. In order to
make Galois descent constructions perfectly clear, we also describe their
connections with some other related constructions of categorical algebra, and
make various explicit calculations, especially with 1-cocycles and
1-dimensional non-abelian cohomology, usually omitted in the literature.


title: Nuclear Masses in Astrophysics

abstract:
  Among all nuclear ground-state properties, atomic masses are highly specific
for each particular combination of N and Z and the data obtained apply to a
variety of physics topics. One of the most crucial questions to be addressed in
mass spectrometry of unstable radionuclides is the one of understanding the
processes of element formation in the Universe. To this end, accurate atomic
mass values of a large number of exotic nuclei participating in nucleosynthesis
are among the key input data in large-scale reaction network calculations. In
this paper, a review on the latest achievements in mass spectrometry for
nuclear astrophysics is given.


title: ParaSasakian manifolds with a constant paraholomorphic section curvature

abstract:
  In this paper paraSasakian manifolds with a constant paraholomorphic section
curvature are considered.


title:
On the existence of the "classical trajectories" of atoms in the
  Stern-Gerlach experiment

abstract:
  The widely accepted interpretation of the Stern-Gerlach experiment assumes
the objective atomic trajectories (the "classical trajectories") in front of
the screen. Following this interpretation, we perform an {\it ab initio}
analysis of the experiment and conclude that the objective trajectories do not
physically exist. The alternative to our conclusion is substantially to change
the model of the experiment.


title:
The relative energy of homogeneous and isotropic universes from
  variational principles

abstract:
  We calculate the relative conserved currents, superpotentials and conserved
quantities between two homogeneous and isotropic universes. In particular we
prove that their relative "energy" (defined as the conserved quantity
associated to cosmic time coordinate translations for a comoving observer) is
vanishing and so are the other conserved quantities related to a Lie subalgebra
of vector fields isomorphic to the Poincar\'e algebra. These quantities are
also conserved in time. We also find a relative conserved quantity for such a
kind of solutions which is conserved in time though non-vanishing. This example
provides at least two insights in the theory of conserved quantities in General
Relativity. First, the contribution of the cosmological matter fluid to the
conserved quantities is carefully studied and proved to be vanishing. Second,
we explicitly show that our superpotential (that happens to coincide with the
so-called KBL potential although it is generated differently) provides strong
conservation laws under much weaker hypotheses than the ones usually required.
In particular, the symmetry generator is not needed to be Killing (nor Killing
of the background, nor asymptotically Killing), the prescription is quasi-local
and it works fine in a finite region too and no matching condition on the
boundary is required.


title: Astrophysical Paradoxes, long version

abstract:
  Astrophysical paradoxes are the paradoxes of physics. The main motivation of
a formulated paradox is clearly recognized in the scientific environment
because the phenomenon of a paradox itself has become interesting. There is an
explanation of how and why the phenomenon of paradox started to exist, as there
is an explanation for the existence of any phenomenon. A paradox has its
structure, which defines the functional aim of creating paradoxes. According to
the structure there are different types of paradoxes in astrophysics and some
of them are going to be classified and analyzed here. Astrophysical paradoxes
have mostly been solved or else there are theoretical premises for their
solution. Their structure is recognizable in two distinct ways that lead to the
solution through changing the paradigm or through a hierarchical sequence
ending in the solution.


title:
Towards a determination of Csw using Numerical Stochastic Perturbation
  Theory (NSPT)

abstract:
  We outline a strategy to compute the second-loop contribution to the Csw
coefficient of the Sheikoleslami-Wohlert-Wilson fermion action by means of
NSPT. We also present preliminary results for higher-order integrators for the
Langevin evolution within NSPT. At fixed numerical accuracy, these integrators
considerably reduce the required computer-time.


title: Hadron Spectroscopy with Dynamical Chirally Improved Fermions

abstract:
  We simulate two dynamical, mass degenerate light quarks on 16^3x32 lattices
with a spatial extent of 2.4 fm using the Chirally Improved Dirac operator. The
simulation method, the implementation of the action and signals of
equilibration are discussed in detail. Based on the eigenvalues of the Dirac
operator we discuss some qualitative features of our approach. Results for
ground state masses of pseudoscalar and vector mesons as well as for the
nucleon and delta baryons are presented.


title: Linear series on semistable curves

abstract:
  The dimension of spaces of global sections for line bundles on semistable
curves parametrized by the compactified Picard scheme is studied. The theorem
of Riemann is shown to hold. The theorem of Clifford is shown to hold in the
following cases: the curve has two components; the curve is any semistable
curve and the degree is either 0 or 2g-2; the curve is stable, free from
separating nodes, and the degree is at most 4. These results are all shown to
be sharp. Applications to the Clifford index, to the combinatorial description
of hyperelliptic curves, and to plane quintics are given.


title: Energy landscapes and their relation to thermodynamic phase transitions

abstract:
  In order to better understand the occurrence of phase transitions, we adopt
an approach based on the study of energy landscapes: The relation between
stationary points of the potential energy landscape of a classical
many-particle system and the analyticity properties of its thermodynamic
functions is studied for finite as well as infinite systems. For finite
systems, each stationary point is found to cause a nonanalyticity in the
microcanonical entropy, and the functional form of this nonanalytic term can be
derived explicitly. With increasing system size, the order of the nonanalytic
term grows unboundedly, leading to an increasing differentiability of the
entropy. Therefore, in the thermodynamic limit, only asymptotically flat
stationary points may cause a phase transition to take place. For several spin
models, these results are illustrated by predicting the absence or presence of
a phase transition from stationary points and their local curvatures in
microscopic configuration space. These results establish a relationship between
properties of energy landscapes and the occurrence of phase transitions. Such
an approach appears particularly promising for the simultaneous study of
dynamical and thermodynamical properties, as is of interest for example for
protein folding or the glass transition.


title: Smooth Frechet Globalizations of Harish-Chandra Modules

abstract:
  An elementary and self-contained approach to smooth Frechet globalizations of
Harish-Chandra modules is presented. We provide applications to the theory of
Eisenstein series and Automatic Continuity.


title: Strong group coalgebras

abstract:
  We introduce strong group coalgebras, as a generalization of strongly graded
coalgebras. We give several characterizations, and study two special types of
strong group coalgebras, namely cleft group algebras (or crossed coproduct
group coalgebras) and smash coproduct group coalgebras.


title: Global homotopy formulas on q-concave CR manifolds for large degrees

abstract:
  Using functional analysis and a Friedrichs approximation lemma for first
order differential operators, we derive a global homotopy formula in large
degrees for the tangential Cauchy-Riemann operator from local homotopy formulas
without loss of regularity.


title:
Sur la pro-p-extension localement cyclotomique maximale d'un corps de
  nombres

abstract:
  Let p be a prime number and F be a number field. We consider the Galois group
G over the cyclotomic Z_p extension of F of the maximal unramified,
p-decomposed, pro-p-extension of the cyclotomic Z_p extension of F. The
question whether G is free pro-p was already asked by many authors. In this
article, we highlight a link between the freeness of G and the Galois descent
for some localisation kernels. Then we give explicit criterions to show that G
is not a free pro-p-group.


title:
Instantaneous identification of Bouc-Wen-type hysteretic systems from
  seismic response data

abstract:
  This paper presents a technique for identification of non-linear hysteretic
systems subjected to non-stationary loading. In the numerical simulations, a
Bouc-Wen model was chosen for its ability to represent the properties of a wide
class of real hysteretic systems. The parameters of the model are computed
instantaneously by approximating the internal restoring force surface through
an "ad hoc" polynomial basis. Instantaneous estimates result from time-varying
spectra of the response signals. A numerical application of interest to
earthquake engineering is finally reported.


title: Sur un crit\`ere de Baez-Duarte pour l'hypoth\`ese de Riemann

abstract:
  Baez-Duarte reformulated the Riemann hypothesis as a statement about a
Hilbert space distance, involving the integer dilations of the "fractional
part" function. Under the assumption of the Riemann hypothesis, we improve on
the currently known estimate for this distance.


title:
Estimating limits from Poisson counting data using Dempster--Shafer
  analysis

abstract:
  We present a Dempster--Shafer (DS) approach to estimating limits from Poisson
counting data with nuisance parameters. Dempster--Shafer is a statistical
framework that generalizes Bayesian statistics. DS calculus augments
traditional probability by allowing mass to be distributed over power sets of
the event space. This eliminates the Bayesian dependence on prior distributions
while allowing the incorporation of prior information when it is available. We
use the Poisson Dempster--Shafer model (DSM) to derive a posterior DSM for the
``Banff upper limits challenge'' three-Poisson model. The results compare
favorably with other approaches, demonstrating the utility of the approach. We
argue that the reduced dependence on priors afforded by the Dempster--Shafer
framework is both practically and theoretically desirable.


title: Hopf-Galois extensions and an exact sequence for $H$-Picard groups

abstract:
  Let $H$ be a Hopf algebra, and $A$ an $H$-Galois extension. We investigate
$H$-Morita autoequivalences of $A$, introduce the concept of $H$-Picard group,
and we establish an exact sequence linking the $H$-Picard group of $A$ and the
Picard group of $A^{{\rm co}H}$.


title: On genericity and weight in the free group

abstract:
  I prove that the generic type of the free nonabelian group has infinite
weight (strengthening non superstability of the free group).


title:
Transient chirp in high speed photonic crystal quantum dots lasers with
  controlled spontaneous emission

abstract:
  We report on a series of experiments on the dynamics of spontaneous emission
controlled nanolasers. The laser cavity is a photonic crystal slab cavity,
embedding self-assembled quantum dots as gain material. The implementation of
cavity electrodynamics effects increases significantly the large signal
modulation bandwidth, with measured modulation speeds of the order of 10 GHz
while keeping an extinction ratio of 19 dB. A linear transient wavelength shift
is reported, corresponding to a chirp of less than 100 pm for a 35-ps laser
pulse. We observe that the chirp characteristics are independent of the
repetition rate of the laser up to 10 GHz.


title:
Analytical model of nanowire FETs in a partially ballistic or
  dissipative transport regime

abstract:
  The intermediate transport regime in nanoscale transistors between the fully
ballistic case and the quasi equilibrium case described by the drift-diffusion
model is still an open modeling issue. Analytical approaches to the problem
have been proposed, based on the introduction of a backscattering coefficient,
or numerical approaches consisting in the MonteCarlo solution of the Boltzmann
transport equation or in the introduction of dissipation in quantum transport
descriptions. In this paper we propose a very simple analytical model to
seamlessly cover the whole range of transport regimes in generic quasi-one
dimensional field-effect transistors, and apply it to silicon nanowire
transistors. The model is based on describing a generic transistor as a chain
of ballistic nanowire transistors in series, or as the series of a ballistic
transistor and a drift-diffusion transistor operating in the triode region. As
an additional result, we find a relation between the mobility and the mean free
path, that has deep consequences on the understanding of transport in nanoscale
devices.


title: Q-Fano threefolds of large Fano index, I

abstract:
  We study Q-Fano threefolds of large Fano index. In particular, we prove that
the maximum of Fano index is attained for the weighted projective space
P(3,4,5,7).


title: Pressure induced FFLO instability in multi-band superconductors

abstract:
  Multi-band systems as intermetallic and heavy fermion compounds have
quasi-particles arising from different orbitals at their Fermi surface. Since
these quasi-particles have different masses or densities, there is a natural
mismatch of the Fermi wave-vectors associated with different orbitals. This
makes these materials potential candidates to observe exotic superconducting
phases as Sarma or FFLO phases, even in the absence of an external magnetic
field. The distinct orbitals coexisting at the Fermi surface are generally
hybridized and their degree of mixing can be controlled by external pressure.
In this Communication we investigate the existence of an FFLO phase in a
two-band BCS superconductor controlled by hybridization. At zero temperature,
as hybridization (pressure) increases we find that the BCS state becomes
unstable with respect to an inhomogeneous superconducting state characterized
by a single wave-vector q.


title: Multiplicative Noise Removal Using L1 Fidelity on Frame Coefficients

abstract:
  We address the denoising of images contaminated with multiplicative noise,
e.g. speckle noise. Classical ways to solve such problems are filtering,
statistical (Bayesian) methods, variational methods, and methods that convert
the multiplicative noise into additive noise (using a logarithmic function),
shrinkage of the coefficients of the log-image data in a wavelet basis or in a
frame, and transform back the result using an exponential function. We propose
a method composed of several stages: we use the log-image data and apply a
reasonable under-optimal hard-thresholding on its curvelet transform; then we
apply a variational method where we minimize a specialized criterion composed
of an $\ell^1$ data-fitting to the thresholded coefficients and a Total
Variation regularization (TV) term in the image domain; the restored image is
an exponential of the obtained minimizer, weighted in a way that the mean of
the original image is preserved. Our restored images combine the advantages of
shrinkage and variational methods and avoid their main drawbacks. For the
minimization stage, we propose a properly adapted fast minimization scheme
based on Douglas-Rachford splitting. The existence of a minimizer of our
specialized criterion being proven, we demonstrate the convergence of the
minimization scheme. The obtained numerical results outperform the main
alternative methods.


title: R-parity violating effects in top quark FCNC productions at LHC

abstract:
  In the minimal supersymmetric model the R-parity violating top quark
interactions, which are so far weakly constrained, can induce various
flavor-changing neutral-current (FCNC) productions for the top quark at the
Large Hadron Collider (LHC). In this work we assume the presence of the
B-violating couplings and examine their contributions to the FCNC productions
proceeding through the parton processes cg -> t, gg -> t c_bar, cg -> t\gamma,
cg -> t Z and cg -> t h. We find that all these processes can be greatly
enhanced relative to the R-parity preserving predictions. In the parameter
space allowed by current experiments, all the production channels except cg ->t
h can reach the 3-sigma sensitivity, in contrast to the R-parity preserving
case in which only cg -> t can reach the 3-sigma sensitivity.


title:
JKCS041: a colour-detected galaxy cluster at z_phot=1.9 with deep
  potential well as confirmed by X-ray data

abstract:
  [Abridged] We report the discovery of JKCS041, a massive near-infrared
selected cluster of galaxies z=1.9. The cluster was originally discovered using
a modified red-sequence method and was also detected in follow-up Chandra data
as extended X-ray source. Optical and near-infrared imaging data alone allow us
to show that the detection of JKCS041 is as secure, even in absence of the
X-ray data. We investigate the possibility that JKCS041 is not a discrete
galaxy cluster at z=1.9, and find other explanations to be unlikely. The X-ray
detection and statistical arguments rule out the hypothesis that JKCS041 is
actually a blend of groups along the line of sight, and we find that the X-ray
emitting gas is too hot and dense to be a filament projected along the line of
sight. The cluster has an X-ray core radius of 36.6 arcsec (about 300 kpc), an
X-ray temperature of 7.4 keV, a bolometric X-ray luminosity within R500 of 7.6
10^44 erg/s, an estimated mass of M500=2.9 10^14 Msol, the latter derived under
the usual (and strong) assumptions. The cluster is composed of 16.4 galaxies
within 1.5 arcmin (750 kpc) brighter than K~20.7 mag. The high redshift of
JKCS041 is determined from the detection colour, from the detection of the
cluster in a galaxy sample formed by z_phot>1.6 galaxies and from a photometric
redshift based on 11-band spectral energy distribution fitting. By means of the
latter we find the cluster redshift to be 1.84<z<2.12 at 68 % confidence.
Therefore, JKCS041 is a cluster of galaxies at z=1.9 with deep potential well,
making it the most distant cluster with extended X-ray emission known.


title: Fluctuation force exerted by a planar self-avoiding polymer

abstract:
  Using results from Schramm Loewner evolution (SLE), we give the expression of
the fluctuation-induced force exerted by a polymer on a small impenetrable
disk, in various 2-dimensional domain geometries. We generalize to two polymers
and examine whether the fluctuation force can trap the object into a stable
equilibrium. We compute the force exerted on objects at the domain boundary,
and the force mediated by the polymer between such objects. The results can
straightforwardly be extended to any SLE interface, including Ising,
percolation, and loop-erased random walks. Some are relevant for extremal value
statistics.


title:
Pressure induced superconductor quantum critical point in multi-band
  systems

abstract:
  In multi-band superconductors as inter-metallic systems and heavy fermions,
external pressure can reduce the critical temperature and eventually destroy
superconductivity driving these systems to the normal state. In many cases this
transition is continuous and is associated with a superconducting quantum
critical point (SQCP). In this work we study a two-band superconductor in the
presence of hybridization V. This one-body mixing term is due to the overlap of
the different wave-functions. It can be tuned by external pressure and turns
out as an important control parameter to study the phase diagram and the nature
of the phase transitions. We use a BCS approximation and include both inter and
intra-band attractive interactions. For negligible inter-band interactions, as
hybridization (pressure) increases we find a SQCP separating a superconductor
from a normal state at a critical value of the hybridization Vc. We obtain the
behavior of the electronic specific heat close to the SQCP and the shape of the
critical line as V approaches Vc.


title: Hadron properties in the nuclear medium

abstract:
  The QCD vacuum shows the dynamical breaking of chiral symmetry. In the
hot/dense QCD medium, the chiral order parameter such as $ < \bar q q > $ is
expected to change as function of temperature $T$ and density $\rho$ of the
medium, and its experimental detection is one of the main challenges in modern
hadron physics. In this article, we discuss theoretical expectations for the
in-medium hadron spectra associated with partial restoration of chiral symmetry
and the current status of experiments with an emphasis on the measurements of
properties of mesons produced in near-ground-state nuclei.


title: Spin-Wave Relaxation in a Quantum Hall Ferromagnet

abstract:
  We study spin wave relaxation in quantum Hall ferromagnet regimes. Spin-orbit
coupling is considered as a factor determining spin nonconservation, and
external random potential as a cause of energy dissipation making spin-flip
processes irreversible. We compare this relaxation mechanism with other
relaxation channels existing in a quantum Hall ferromagnet.


title: Spiky Strings and Spin Chains

abstract:
  We determine spectral curves for the known spiky string solutions in AdS
space in the limit of large angular momentum. We also construct generic
multi-spike solutions in this limit and compute the corresponding spectral
data. The resulting spectral curves precisely match those of the classical spin
chain describing the dual operators in one-loop gauge theory. Our results
confirm the map between string theory and gauge theory degrees of freedom
proposed in arXiv:0805.4387 [hep-th].


title:
Lowest dimensional example on non-universality of generalized
  In\"on\"u-Wigner contractions

abstract:
  We prove that there exists just one pair of complex four-dimensional Lie
algebras such that a well-defined contraction among them is not equivalent to a
generalized IW-contraction (or to a one-parametric subgroup degeneration in
conventional algebraic terms). Over the field of real numbers, this pair of
algebras is split into two pairs with the same contracted algebra. The example
we constructed demonstrates that even in the dimension four generalized
IW-contractions are not sufficient for realizing all possible contractions, and
this is the lowest dimension in which generalized IW-contractions are not
universal. Moreover, this is also the first example of nonexistence of
generalized IW-contraction for the case when the contracted algebra is not
characteristically nilpotent and, therefore, admits nontrivial diagonal
derivations. The lower bound (equal to three) of nonnegative integer parameter
exponents which are sufficient to realize all generalized IW-contractions of
four-dimensional Lie algebras is also found.


title: Approximate quantum and acoustic cloaking

abstract:
  At any energy E > 0, we construct a sequence of bounded potentials $V^E_{n},
n\in\N$, supported in an annular region $B_{out}\setminus B_{inn}$ in
three-space, which act as approximate cloaks for solutions of Schr\"odinger's
equation: For any potential $V_0\in L^\infty(B_{inn})$ such that E is not a
Neumann eigenvalue of $-\Delta+V_0$ in $B_{inn}$, the scattering amplitudes
$a_{V_0+V_n^E}(E,\theta,\omega)\to 0$ as $n\to\infty$. The $V^E_{n}$ thus not
only form a family of approximately transparent potentials, but also function
as approximate invisibility cloaks in quantum mechanics. On the other hand, for
$E$ close to interior eigenvalues, resonances develop and there exist {\it
almost trapped states} concentrated in $B_{inn}$. We derive the $V_n^E$ from
singular, anisotropic transformation optics-based cloaks by a
de-anisotropization procedure, which we call \emph{isotropic transformation
optics}. This technique uses truncation, inverse homogenization and spectral
theory to produce nonsingular, isotropic approximate cloaks. As an intermediate
step, we also obtain approximate cloaking for a general class of equations
including the acoustic equation.


title:
From density to interface fluctuations: the origin of wavelength
  dependence in surface tensions

abstract:
  The height-height correlation function for a fluctuating interface between
two coexisting bulk phases is derived by means of general equilibrium
properties of the corresponding density-density correlation function. A
wavelength-dependent surface tension $\gamma(\mathbf{q})$ can be defined and
expressed in terms of the direct correlation function
$c(\mathbf{r},\mathbf{r}')$, the equilibrium density profile
$\rho_{\circ}(\mathbf{r})$ and an operator which relates density to surface
configurations. Neither the concept of an effective interface Hamiltonian nor
the difference in pressure is needed to determine the general structure of the
height-height correlations or $\gamma(\mathbf{q})$, respectively. This result
generalizes the Mecke/Dietrich surface tension $\gmd$ (Phys. Rev. E {\bf 59},
p. 6766 (1999)) and modifies recently published criticism concerning $\gmd$ (P.
Tarazona, R. Checa and, E.Chac\'{o}n: Phys. Rev. Lett. {\bf 99}, p. 196101
(2007)).


title:
Physical and chemical conditions in methanol maser selected hot-cores
  and UCHII regions

abstract:
  We present the results of a targeted 3-mm spectral line survey towards the
eighty-three 6.67 GHz methanol maser selected star forming clumps observed by
Purcell et al. 2006. In addition to the previously reported measurements of
HCO+ (1 - 0), H13CO+ (1 - 0), and CH3CN (5 - 4) & (6 -5), we used the Mopra
antenna to detect emission lines of N2H+ (1 - 0), HCN (1 - 0) and HNC (1 - 0)
towards 82/83 clumps (99 per cent), and CH3OH (2 - 1) towards 78/83 clumps (94
per cent). The molecular line data have been used to derive virial and LTE
masses, rotational temperatures and chemical abundances in the clumps, and
these properties have been compared between sub-samples associated with
different indicators of evolution. The greatest differences are found between
clumps associated with 8.6 GHz radio emission, indicating the presence of an
Ultra-Compact HII region, and `isolated' masers (without associated radio
emission), and between clumps exhibiting CH3CN emission and those without. In
particular, thermal CH3OH is found to be brighter and more abundant in
Ultra-Compact HII (UCHII) regions and in sources with detected CH3CN, and may
constitute a crude molecular clock in single dish observations. Clumps
associated with 8.6 GHz radio emission tend to be more massive and more
luminous than clumps without radio emission. This is likely because the most
massive clumps evolve so rapidly that a Hyper-Compact HII or UCHII region is
the first visible tracer of star-formation. The gas-mass to sub-mm/IR
luminosity relation for the combined sample was found to be L proportional to
M**0.68, considerably shallower than expected for massive main-sequence stars.


title:
Many Body Theory for Quartets, Trions, and Pairs in Low Density
  Multi-Component Fermi-Systems

abstract:
  A selfconsistent many body approach for the description of gases with
quartets, trions, and pairs is presented. Applications to 3D Fermi systems at
low density are discussed.


title:
Sensitivity and environmental response of the CMS RPC gas gain
  monitoring system

abstract:
  Results from the gas gain monitoring
  (GGM) system for the muon detector using RPC in the CMS experiment at the LHC
is presented.
  The system is designed to provide fast and accurate determination of any
shift in the working point of the chambers due to gas mixture changes.


title:
The most compact scission configuration of fragments from low energy
  fission of U 234 and U 236

abstract:
  Using a time of flight technique, the maximal values of kinetic energy as a
function of primary mass of fragments from low energy fission of U 234 and U
236 were measured by Signarbieux et al. From calculations of scission
configurations, one can conclude that, for those two fissioning systems, the
maximal value of total kinetic energy corresponding to fragmentations (Mo 104,
Sn 130)) and (Mo 106, Sn 130), respectively, are equal to the available
energies, and their scission configurations are composed by a spherical heavy
fragment and a prolate light fragment both in their ground state.


title: Heteroclinic travelling waves in convex FPU-type chains

abstract:
  We consider infinite FPU-type atomic chains with general convex potentials
and study the existence of monotone fronts that are heteroclinic travelling
waves connecting constant asymptotic states. Iooss showed that small amplitude
fronts bifurcate from convex-concave turning points of the force. In this paper
we prove that fronts exist for any asymptotic states that satisfy certain
constraints. For potentials whose derivative has exactly one turning point
these constraints precisely mean that the front corresponds to an energy
conserving supersonic shock of the `p-system', which is the naive hyperbolic
continuum limit of the chain. The proof goes via minimizing an action
functional for the deviation from this discontinuous shock profile. We also
discuss qualitative properties and the numerical computation of fronts.


title: Secret Communication with Feedback

abstract:
  Secure communication with feedback is studied. An achievability scheme in
which the backward channel is used to generate a shared secret key is proposed.
The scenario of binary symmetric forward and backward channels is considered,
and a combination of the proposed scheme and Maurer's coding scheme is shown to
achieve improved secrecy rates. The scenario of a Gaussian channel with perfect
output feedback is also analyzed and the Schalkwijk-Kailath coding scheme is
shown to achieve the secrecy capacity for this channel.


title:
Cold CO in circumstellar disks: On the effects of photodesorption and
  vertical mixing

abstract:
  Aims. We attempt to understand the presence of gas phase CO below its
freezing temperature in circumstellar disks. We study two promising mechanisms
to explain this phenomenon: turbulent mixing and photodesorption. Methods. We
compute the chemical evolution of circumstellar disks including grain surface
reactions with and without turbulent mixing and CO photodesorption. Results. We
show that photodesorption significantly enhances the gas phase CO abundance, by
extracting CO from the grains when the visual extinction remains below about 5
magnitudes. However the resulting dependence of column density on radial
distance is not consistent with observations so far. We propose that this
inconsistency could be the result of grain growth. On the other hand, the
influence of turbulent mixing is not found to be straightforward. The
efficiency of turbulent mixing depends upon a variety of parameters, including
the disk structure. For the set of parameters we chose, turbulent mixing is not
found to have any significant influence on the CO column density.


title:
Quantized spin waves in the metallic state of magnetoresistive
  manganites

abstract:
  High resolution spin waves measurements have been carried out in
ferromagnetic (F) La(1-x)(Sr,Ca)xMnO3 with x(Sr)=0.15, 0.175, 0.2, 0.3 and
x(Ca)=0.3. In all q-directions, close to the zone boundary, the spin wave
spectra consist of several energy levels, with the same values in the metallic
and the x\approx 1/8 ranges. Mainly the intensity varies, jumping from the
lower energy levels determined in the x\approx 1/8 range to the higher energy
ones observed in the metallic state. On the basis of a quantitative agreement
found for x(Sr)=0.15 in a model of ordered 2D clusters, the spin wave anomalies
of the metallic state can be interpreted in terms of quantized spin waves
within the same 2D clusters, embedded in a 3D matrix.


title: Beyond Kirillov-Reshetikhin modules

abstract:
  In this survey, we shall be concerned with the category of finite-dimensional
representations of the untwisted quantum affine algebras when the quantum
parameter q is not a root of unity. We review the foundational results of the
subject, including the Drinfeld presentation, the classification of simple
modules and q-characters. We then concentrate on particular families of
irreducible representations whose structure has recently been understood:
Kirillov-Reshetikhin modules, minimal affinizations and beyond.


title:
Influence of crystal anisotropy on elastic deformation and onset of
  plasticity in nanoindentation -- a simulational study

abstract:
  Using molecular-dynamics simulation and finite-element modelling, we simulate
nanoindentation into the three principal surfaces -- the (100), (110) and (111)
surface -- of Cu and Al. In the elastic regime, the simulation data agree
fairly well with the linear elastic theory of indentation into an elastically
anisotropic substrate. With increasing indentation, the effect of pressure
hardening becomes visible. When the critical stress for dislocation nucleation
is reached, even the elastically isotropic Al shows a strong dependence of the
surface orientation on the force-displacement curves. After the load drop, when
plasticity ahs set in, the influence of the surface orientation is lost, and
the contact pressure (hardness) becomes independent of the surface orientation.


title:
The JCMT Nearby Galaxies Legacy Survey I. Star Forming Molecular Gas in
  Virgo Cluster Spiral Galaxies

abstract:
  We present large-area maps of the CO J=3-2 emission obtained at the James
Clerk Maxwell Telescope for four spiral galaxies in the Virgo Cluster. We
combine these data with published CO J=1-0, 24 micron, and Halpha images to
measure the CO line ratios, molecular gas masses, and instantaneous gas
depletion times. For three galaxies in our sample (NGC 4254, NGC4321, and NGC
4569), we obtain molecular gas masses of 7E8-3E9 Msun and disk-averaged
instantaneous gas depletion times of 1.1-1.7 Gyr. We argue that the CO J=3-2
line is a better tracer of the dense star forming molecular gas than the CO
J=1-0 line, as it shows a better correlation with the star formation rate
surface density both within and between galaxies. NGC 4254 appears to have a
larger star formation efficiency(smaller gas depletion time), perhaps because
it is on its first passage through the Virgo Cluster. NGC 4569 shows a
large-scale gradient in the gas properties traced by the CO J=3-2/J=1-0 line
ratio, which suggests that its interaction with the intracluster medium is
affecting the dense star-forming portion of the interstellar medium directly.
The fourth galaxy in our sample, NGC 4579, has weak CO J=3-2 emission despite
having bright 24 micron emission; however, much of the central luminosity in
this galaxy may be due to the presence of a central AGN.


title:
Exponential inequalities for martingales and asymptotic properties of
  the free energy of directed polymers in random environment

abstract:
  The objective of the present paper is to establish exponential large
deviation inequalities, and to use them to show exponential concentration
inequalities for the free energy of a polymer in general random environment,
its rate of convergence, and an expression of its limit value in terms of those
of some multiplicative cascades.


title: On densest packings of equal balls of $\rb^{n}$ and Marcinkiewicz spaces

abstract:
  We investigate, by "a la Marcinkiewicz" techniques applied to the
(asymptotic) density function, how dense systems of equal spheres of $\rb^{n},
n \geq 1,$ can be partitioned at infinity in order to allow the computation of
their density as a true limit and not a limsup. The density of a packing of
equal balls is the norm 1 of the characteristic function of the systems of
balls in the sense of Marcinkiewicz. Existence Theorems for densest sphere
packings and completely saturated sphere packings of maximal density are given
new direct proofs.


title:
Derivation of a two-fluids model for a Bose gas from a quantum kinetic
  system

abstract:
  We formally derive the hydrodynamic limit of a system modelling a bosons gas
having a condensed part, made of a quantum kinetic and a Gross-Pitaevskii
equation. The limit model, which is a two-fluids Euler system, is approximated
by an isentropic system, which is then studied. We find in particular some
conditions for the hyperbolicity, and we study the weak solutions. A numerical
example is given at the end.


title:
Probe of anomalous neutrino couplings to W and Z in medium energy setup
  of a beta-beam facility

abstract:
  Capability of medium energy setup of a beta beam experiment to probe new
physics contributions to neutrino-W and neutrino-Z couplings are investigated.
We employ the effective lagrangian approach of Buchmuller and Wyler and obtain
95% confidence level limits on neutrino couplings to these gauge bosons without
assuming the flavor universality of the coupling of neutrinos. We show that a
beta beam facility can place 3 to 20 times more restrictive limits than present
ones on the deviations from the electron neutrino couplings in the Standard
Model.


title: Size dependent exciton g-factor in self-assembled InAs/InP quantum dots

abstract:
  We have studied the size dependence of the exciton g-factor in self-assembled
InAs/InP quantum dots. Photoluminescence measurements on a large ensemble of
these dots indicate a multimodal height distribution. Cross-sectional Scanning
Tunneling Microscopy measurements have been performed and support the
interpretation of the macro photoluminescence spectra. More than 160 individual
quantum dots have systematically been investigated by analyzing single dot
magneto-luminescence between 1200nm and 1600 nm. We demonstrate a strong
dependence of the exciton g-factor on the height and diameter of the quantum
dots, which eventually gives rise to a sign change of the g-factor. The
observed correlation between exciton g-factor and the size of the dots is in
good agreement with calculations. Moreover, we find a size dependent anisotropy
splitting of the exciton emission in zero magnetic field.


title: On Bialostocki's conjecture for zero-sum sequences

abstract:
  Let $n$ be a positive even integer, and let $a_1,...,a_n$ and $w_1, ..., w_n$
be integers satisfying $\sum_{k=1}^n a_k\equiv\sum_{k=1}^n w_k =0 (mod n)$. A
conjecture of Bialostocki states that there is a permutation $\sigma$ on
{1,...,n} such that $\sum_{k=1}^n w_k a_{\sigma(k)}=0 (mod n)$. In this paper
we confirm the conjecture when $w_1,...,w_n$ form an arithmetic progression
with even common difference.


title:
Jahn-Teller induced Berry phase in spin-orbit coupled Bose-Einstein
  condensates

abstract:
  We demonstrate that Berry phases may greatly affect the dynamics of
spin-orbit coupled Bose-Einstein condensates. The effective model Hamiltonian
under consideration is shown to be equivalent to the Exe Jahn-Teller model
first introduced in molecular physics. The corresponding conical intersection
is identified and the Berry phase acquired for a wave packet encircling the
intersection studied. It is found that this phase manifests itself in the
density profile of the condensate, making it a directly measurable quantity via
time-of-flight detection. Moreover, the non-Abelian gauge structure of the
system is addressed and we verify how it affects the dynamics.


title:
Existence and uniqueness of solutions of stochastic functional
  differential equations

abstract:
  We provide sufficient conditions on the coefficients of a stochastic
functional differential equation with bounded memory driven by Brownian motion
which guarantee existence and uniqueness of a maximal local and global strong
solution for each initial condition. Our results extend those of previous
works. For local existence and uniqueness, we only require the coefficients to
be continuous and to satisfy a one-sided local Lipschitz (or monotonicity)
condition. In an appendix we formulate and prove four lemmas which may be of
independent interest: three of them can be viewed as rather general stochastic
versions of Gronwall's Lemma, the final one - which we call Dereich-Lemma -
provides tail bounds for Hoelder norms of stochastic integrals.


title: Photometric properties of resolved and unresolved magnetic elements

abstract:
  We investigate the photometric signature of magnetic flux tubes in the solar
photosphere. We developed two dimensional, static numerical models of isolated
and clustered magnetic flux tubes. We investigated the emergent intensity
profiles at different lines-of-sight for various spatial resolutions and
opacity models. We found that both geometric and photometric properties of
bright magnetic features are determined not only by the physical properties of
the tube and its surroundings, but also by the particularities of the
observations, including the line/continuum formation height, the spatial
resolution and the image analyses techniques applied. We show that some
observational results presented in the literature can be interpreted by
considering bright magnetic features to be clusters of smaller elements, rather
than a monolithic flux tube.


title: Consistency Spaces

abstract:
  We introduce the concept of a consistency space. The idea of the consistency
space is motivated by the question, Given only the collection of sets of
sentences which are logically consistent, is it possible to reconstruct their
lattice structure?


title: The Wadge Hierarchy of Deterministic Tree Languages

abstract:
  We provide a complete description of the Wadge hierarchy for
deterministically recognisable sets of infinite trees. In particular we give an
elementary procedure to decide if one deterministic tree language is
continuously reducible to another. This extends Wagner's results on the
hierarchy of omega-regular languages of words to the case of trees.


title:
Optical quantum memory with generalized time-reversible atom-light
  interactions

abstract:
  We examine a quantum memory scheme based on controllable dephasing of atomic
coherence of a non-resonant, inhomogeneously broadened Raman transition. We
show that it generalizes the physical conditions for time-reversible
interaction between light and atomic ensembles from weak to strong fields and
from linear to non-linear interactions. We also develop a unified framework for
different realizations exploiting either controlled reversible inhomogeneous
broadening or atomic frequency combs, and discuss new aspects related to
storage and manipulation of quantum states.


title: Noncommutative fermions and quarkonia decays

abstract:
  The recent introduction of a deformed non-minimal version of the
noncommutative Standard Model in the enveloping-algebra approach, having a
one-loop renormalisable gauge sector involving a higher order gauge term,
motivates us to consider the possibility of extending the fermion sector with
additional deformations, i.e. higher order fermionic terms. Since the
renormalisability properties of the fermion sector of the model are not yet
fully known, we work with an effective fermion lagrangian which includes
noncommutative higher order terms involving a contraction with the
noncommutative $\theta$ tensor aside from the star products, so that these
terms annihilate in the commutative limit. Some of these terms violate CPT in
the weak sector, and some violate CP in the strong and hypercharge sectors. We
apply this framework to the reevaluation of the decay rates of quarkonia
(\bar{q}q_{1} = J/\psi, \Upsilon) into two photons. These decays, which are
forbidden in the ordinary Standard Model, had been previously studied as
possible signals for noncommutativity, but not in the framework of the better
behaved deformed non-minimal version of the noncommutative Standard Model. Weak
CPT or strong-hypercharge CP violating interactions do not contribute to the
result. If the parameters of the model take natural values, for the vast
majority of configurations the resulting branching ratios are enhanced with
respect to their values in the minimal version of the noncommutative Standard
Model. Also for more than half of the parameter space, the rates are larger
than the maximal rates that were calculated in the undeformed version of the
non-minimal noncommutative Standard Model. Tuning the dimensionless parameters
the predicted branching ratios can fall within the current experimental bounds.


title: Thick DGP braneworlds

abstract:
  We study Dvali-Gabadadze-Porrati braneworlds with finite thickness. In
respect to standard (thin) DGP Friedmann equation, finite thickness of the
brane causes a subtle modification of the cosmological equations that can lead
to significant physical consequences. The resulting cosmology is governed by
two length scales which are associated with the brane thickness and with the
crossover length respectively. In this setup both early inflation and late-time
acceleration of the expansion are a consequence of the 5D geometry. At early
times, as well as at late times, 5D effects become dominant (gravity leaks into
the extra dimension), while, at intermediate times, gravity is effectively 4D
due to non-trivial physics occuring in standard (thin) DGP scenarios.


title:
Current Distribution Models for the Earth's Main Magnetic Field: A
  Discrete Inverse Theory Approach

abstract:
  Current source models for the Earth's main geomagnetic field are calculated
employing conventional discrete inverse theory methods. Source structures are
spherical surfaces placed at the surface of the Earth's core, and at the
surface of the Earth. The data set consists of measurements taken by the MAGSAT
satellite in 1979. The resulting current distributions are discussed in
relation to dipole and current loop models.


title:
Self-interacting Scalar Field Trapped in a Randall-Sundrum Braneworld:
  The Dynamical Systems Perspective

abstract:
  We apply the dynamical systems tools to study the linear dynamics of a
self-interacting scalar field trapped on a Randall-Sundrum brane. The simplest
kinds of self-interaction potentials are investigated: a) constant potential,
and b) exponential potential. It is shown that the dynamics of the
Randall-Sundrum model significantly differs from the standard four-dimensional
behavior at early times: in all cases of interest the (singular) empty universe
is the past attractor for every trajectory in phase space, meanwhile the
kinetic energy-dominated solution is always a saddle critical point. The
late-time dynamics is not affected by the brane effects.


title:
Pulse Shape Analysis with a Broad-Energy Germanium Detector for the
  GERDA experiment

abstract:
  To reduce background in experiments looking for rare events, such as the
GERDA double beta decay experiment, it is necessary to employ active
background-suppression techniques. One of such techniques is the pulse shape
analysis of signals induced by the interaction of radiation with the detector.
Analysis of the time-development of the impulses can distinguish between an
interaction of an electron and an interaction of a multiple-scattered photon
inside the detector. This information can be used to eliminate background
events from the recorded data. Results of pulse-shape analysis of signals from
a commercially available broad-energy germanium detector are presented and the
pulse-shape discrimination capability of such detector configuration for use in
low-background experiments is discussed.


title: Classical QGP : III. The free energy

abstract:
  We explore further the classical QGP using methods from classical liquids.
The partition function of an ensemble of SU(N_c) colored charge spheres is
constructed. We analyze it using a cumulant expansion (low density) and a loop
expansion (high temperature) after resumming the Debye screening effects. The
pertinent free energies are derived in both limits and compared to recent
molecular dynamics results.


title: Variational Principles for Reduced Plasma Physics

abstract:
  Reduced equations that describe low-frequency plasma dynamics play an
important role in our understanding of plasma behavior over long time scales.
One of the oldest paradigms for reduced plasma dynamics involves the
ponderomotive Hamiltonian formulation of the oscillation-center dynamics of
charged particles (over slow space-time scales) in a weakly-nonuniform
background plasma perturbed by an electromagnetic field with fast space-time
scales. These reduced plasma equations are derived here by Lie-transform and
variational methods for the case of a weakly-magnetized background plasma. In
particular, both methods are used to derive explicit expressions for the
ponderomotive polarization and magnetization, which appear in the
oscillation-center Vlasov-Maxwell equations.


title: Pseudo-complex General Relativity

abstract:
  An extension of the theory of General Relativity is proposed, based on
pseudo-complex space-time coordinates. The new theory corresponds to the
introduction of two, in general different, metrics which are connected through
specific conditions. A pseudo-complex Schwarzschild solution is constructed,
which does not suffer any more by a singularity. The solution indicates a
minimal radius for a heavy mass object. Consequences for the redshift and
possible signatures for its observation are discussed.


title:
Critical comments on the paper "Crossing $\omega=-1$ by a single scalar
  field on a Dvali-Gabadadze-Porrati brane" by H Zhang and Z-H Zhu
  [Phys.Rev.D75,023510(2007)]

abstract:
  It is demonstrated that the claim in the paper "Crossing $\omega=-1$ by a
single scalar field on a Dvali-Gabadadze-Porrati brane" by H Zhang and Z-H Zhu
[Phys.Rev.D75,023510(2007)], about a prove that there do not exist scaling
solutions in a universe with dust in a Dvali-Gabadadze-Porrati (DGP) braneworld
scenario, is incorrect.


title:
Numerical study of chiral symmetry breaking in non-Abelian gauge theory
  with background magnetic field

abstract:
  We investigate the effect of a uniform background magnetic field on the
chiral symmetry breaking in SU(2) Yang-Mills theory on the lattice. We observe
that the chiral condensate grows linearly with the field strength B up to
\sqrt{e B} = 3 GeV as predicted by chiral perturbation theory for full QCD. As
the temperature increases the coefficient in front of the linear term gets
smaller. In the magnetic field near-zero eigenmodes of the Dirac operator tend
to have more regular structure with larger (compared to zero-field case)
Hausdorff dimensionality. We suggest that the delocalization of near-zero
eigenmodes plays a crucial role in the enhancement of the chiral symmetry
breaking.


title: Classical QGP : IV. Thermodynamics

abstract:
  We construct the equation of a state of the classical QGP valid for all
values of Gamma=V/K, the ratio of the mean Coulomb to kinetic energy. By
enforcing the Gibbs relations, we derive the pertinent pressure and entropy
densities for all Gamma. For the case of an SU(2) classical gluonic plasma our
results compare well with lattice simulations. We show that the strongly
coupled component of the classical QGP contributes significantly to the bulk
thermodynamics across T_c.


title:
Chemical Doping and Electron-Hole Conduction Asymmetry in Graphene
  Devices

abstract:
  We investigate polyethylene imine and diazonium salts as stable,
complementary dopants on graphene. Transport in graphene devices doped with
these molecules exhibits asymmetry in electron and hole conductance. The
conductance of one carrier is preserved, while the conductance of the other
carrier decreases. Simulations based on nonequilibrium Green's function
formalism suggest that the origin of this asymmetry is imbalanced carrier
injection from the graphene electrodes caused by misalignment of the electrode
and channel neutrality points.


title:
Axisymmetric mass models of S0 and spiral galaxies with boxy bulges:
  mass-to-light ratios, dark matter and bars

abstract:
  We examine a sample of 30 edge-on spiral and S0 galaxies that have boxy and
peanut-shaped bulges. We compute model stellar kinematics by solving the Jeans
equations for axisymmetric mass distributions derived from K-band images. These
simple models have only one free parameter: the dynamical mass-to-light ratio,
which we assume is independent of radius. Given the simplicity of the modelling
procedure, the model second velocity moments are strikingly good fits to the
observed stellar kinematics within the extent of our kinematic data, which
typically reach ~ 0.5-1 R25 (where R25 is the optical radius), or equivalently
2-3 Re (where Re is the effective or half-light radius). We therefore find no
evidence for a dominant dark matter component within the optical disk of spiral
galaxies. This is equally true of the S0s in our sample, which significantly
extends previous observational constraints on dark matter in these galaxies.
The predicted kinematics do deviate slightly but systematically from the
observations in the bulge region of most galaxies, but we argue that this is
consistent with the claim that boxy and peanut-shaped bulges are bars viewed
edge-on.


title:
Auger-like Relaxation of Inter-Landau-Level Magneto-Plasmon Excitations
  in the Quantised Hall Regime

abstract:
  Auger relaxation in 2D strongly correlated electron gas can be represented as
an Auger-like process for neutral magnetoplasmon excitations. The case of
"dielectric" state with lack of free electrons (i.e. at integer filling $\nu$)
is considered. Really the Auger-like process is a coalescence of two
magnetoplasmons which are converted into a single one of a different plasmon
mode with zero 2D wave-vector. This event turns out to be energetically allowed
for magnetoplasmons near their roton minima where the spectrum has the infinite
density of states. As a result the additional possibility appears for indirect
observation of the magnetorotons by means of anti-Stokes Raman scattering. We
find the rate of this process employing the technique of Excitonic
Representation for the relevant matrix element calculation.


title:
Multifractal analysis of Lyapunov exponent for the backward continued
  fraction map

abstract:
  In this note we study the multifractal spectrum of Lyapunov exponents for
interval maps with infinitely many branches and a parabolic fixed point. It
turns out that, in strong contrast with the hyperbolic case, the domain of the
spectrum is unbounded and points of non-differentiability might exist.
Moreover, the spectrum is not concave. We establish conditions that ensure the
existence of inflection points. We also study the thermodynamic formalism for
such maps. We prove that the pressure function is real analytic in a certain
interval and then it becomes equal to zero.


title: Mechanical switching of ferro-electric rubber

abstract:
  At the A to C transition, smectic elastomers have recently been observed to
undergo $\sim$35% spontaneous shear strains. We first explicitly describe how
strains of up to twice this value could be mechanically or electrically induced
in Sm-$C$ elastomers by rotation of the director on a cone around the layer
normal at various elastic costs depending on constraints. Secondly, for typical
sample geometries, we give the various microstructures in Sm-$C$ akin to those
seen in nematic elastomers under distortions with constraints. It is possible
to give explicit results for the nature of the textures. Chiral Sm-$C$
elastomers are ferro-electric. We calculate how the polarization could be
mechanically reversed by large, hard or soft strains of the rubber, depending
upon sample geometry.


title: Parameter estimation with cluster states

abstract:
  We propose a scheme for parameter estimation with cluster states. We find
that phase estimation with cluster states under a many-body Hamiltonian and
separable measurements leads to a precision at the Heisenberg limit. As noise
models we study the dephasing, depolarizing, and pure damping channels.
Decoherence reduces the sensitivity but our scheme remains superior over
several reference schemes with states such as maximally entangled states and
product states. For small cluster states and fixed evolution times it remains
at the Heisenberg limit for approximately 2 times as many qubits than
alternative schemes.


title: Space-time models derived from Schwarzschild's solution

abstract:
  We discuss two space-time models: one is expanding, the other is static. They
are both derived from Schwarzschild's exterior solution. But they differ in the
implementation of the parallelism at a distance and the choice of their master
frame of reference.


title: Holomorphic Parabolic Geometries and Calabi-Yau Manifolds

abstract:
  We prove that the only complex parabolic geometries on Calabi-Yau manifolds
are the homogeneous geometries on complex tori. We also classify the complex
parabolic geometries on homogeneous compact K\"ahler manifolds.


title: On the Origin of Cores in Simulated Galaxy Clusters

abstract:
  (Abridged) The thermal state of the intracluster medium results from a
competition between gas cooling and heating. The heating comes from two
distinct sources: gravitational heating from the collapse of the dark matter
halo and thermal input from galaxy/black hole formation. However, a long
standing problem has been that cosmological simulations based on smoothed
particle hydrodynamics (SPH) and Eulerian mesh codes predict different results
even when cooling and galaxy/black hole heating are switched off. Clusters
formed in SPH simulations show near powerlaw entropy profiles, while those
formed in mesh simulations develop a core and do not allow gas to reach such
low entropies. Since the cooling rate is closely connected to the minimum
entropy of the gas, the differences are of potentially key importance.
  In this paper, we investigate the origin of this discrepancy. By comparing
simulations run using the GADGET-2 SPH code and the FLASH adaptive Eulerian
mesh code, we show that the discrepancy arises during the idealised merger of
two clusters. The difference is not sensitive to the resolution of our
simulations, nor is it is due differences in the gravity solvers, Galilean
non-invariance of the mesh code, or an effect of unsuitable artificial
viscosity in the SPH code. Instead, we find that the difference is inherent to
the treatment of eddies and fluid instabilities. These are suppressed in the
SPH simulations, while the cluster mergers generate strong vortices in the mesh
simulations that efficiently mix the fluid and erase the low entropy gas.
Consequently, particles in the SPH simulations retain a close connection to
their initial entropy, while this connection is much weaker in the mesh
simulations. We discuss the potentially profound implications of these results.