title: Quadratic Volume-Preserving Maps: Invariant Circles and Bifurcations

abstract:
  We study the dynamics of the five-parameter quadratic family of
volume-preserving diffeomorphisms of R^3. This family is the unfolded normal
form for a bifurcation of a fixed point with a triple-one multiplier and also
is the general form of a quadratic three-dimensional map with a quadratic
inverse. Much of the nontrivial dynamics of this map occurs when its two fixed
points are saddle-foci with intersecting two-dimensional stable and unstable
manifolds that bound a spherical ``vortex-bubble''. We show that this occurs
near a saddle-center-Neimark-Sacker (SCNS) bifurcation that also creates, at
least in its normal form, an elliptic invariant circle. We develop a simple
algorithm to accurately compute these elliptic invariant circles and their
longitudinal and transverse rotation numbers and use it to study their
bifurcations, classifying them by the resonances between the rotation numbers.
In particular, rational values of the longitudinal rotation number are shown to
give rise to a string of pearls that creates multiple copies of the original
spherical structure for an iterate of the map.


title: Flat rotation curves in Chern-Simons modified gravity

abstract:
  We investigate the spacetime of a slowly rotating black hole in the
Chern-Simons modified gravity. The long range feature of frame-dragging effect
under the Chern-Simon gravity well explains the flat rotation curves of
galaxies which is a central evidence of dark matter. Our solution provides a
different scenario of rotating space from Goedel's solution.


title: Tides and the Evolution of Planetary Habitability

abstract:
  Tides raised on a planet by its host star's gravity can reduce a planet's
orbital semi-major axis and eccentricity. This effect is only relevant for
planets orbiting very close to their host stars. The habitable zones of
low-mass stars are also close-in and tides can alter the orbits of planets in
these locations. We calculate the tidal evolution of hypothetical terrestrial
planets around low-mass stars and show that tides can evolve planets past the
inner edge of the habitable zone, sometimes in less than 1 billion years. This
migration requires large eccentricities (>0.5) and low-mass stars (<0.35
M_Sun). Such migration may have important implications for the evolution of the
atmosphere, internal heating and the Gaia hypothesis. Similarly, a planet
detected interior to the habitable zone could have been habitable in the past.
We consider the past habitability of the recently-discovered, ~5 M_Earth
planet, Gliese 581 c. We find that it could have been habitable for reasonable
choices of orbital and physical properties as recently as 2 Gyr ago. However,
when we include constraints derived from the additional companions, we see that
most parameter choices that predict past habitability require the two inner
planets of the system to have crossed their mutual 3:1 mean motion resonance.
As this crossing would likely have resulted in resonance capture, which is not
observed, we conclude that Gl 581 c was probably never habitable.


title:
A new Monte Carlo method to study the fluid-solid phase transition of
  polydisperse hard spheres

abstract:
  A new Monte Carlo approach is proposed to investigate the fluid-solid phase
transition of the polydisperse system. By using the extended ensemble, a
reversible path was constructed to link the monodisperse and corresponding
polydisperse system. Once the fluid-solid coexistence point of the monodisperse
system is known, the fluid-solid coexistence point of the polydisperse system
can be obtained from the simulation. The validity of the method is checked by
the simulation of the fluid-solid phase transition of a size-polydisperse hard
sphere colloid. The results are in agreement with the previous studies.


title:
Loop updates for variational and projector quantum Monte Carlo
  simulations in the valence-bond basis

abstract:
  We show how efficient loop updates, originally developed for Monte Carlo
simulations of quantum spin systems at finite temperature, can be combined with
a ground-state projector scheme and variational calculations in the valence
bond basis. The methods are formulated in a combined space of spin z-components
and valence bonds. Compared to schemes formulated purely in the valence bond
basis, the computational effort is reduced from up to O(N^2) to O(N) for
variational calculations, where N is the system size, and from O(m^2) to O(m)
for projector simulations, where m>> N is the projection power. These
improvements enable access to ground states of significantly larger lattices
than previously. We demonstrate the efficiency of the approach by calculating
the sublattice magnetization M_s of the two-dimensional Heisenberg model to
high precision, using systems with up to 256*256 spins. Extrapolating the
results to the thermodynamic limit gives M_s=0.30743(1). We also discuss
optimized variational amplitude-product states, which were used as trial states
in the projector simulations, and compare results of projecting different types
of trial states.


title: A Magnetic Flux Tube Oscillation Model for QPOs in SGR Giant Flares

abstract:
  Giant flares from soft gamma-ray repeaters (SGRs) are one of the most violent
phenomena in neutron stars. Quasi-periodic oscillations (QPOs) with frequencies
ranging from 18 to 1840 Hz have been discovered in the tails of giant flares
from two SGRs, and were ascribed to be seismic vibrations or torsional
oscillations of magnetars. Here we propose an alternative explanation for the
QPOs in terms of standing sausage mode oscillations of flux tubes in the
magnetar coronae. We show that most of the QPOs observed in SGR giant flares
could be well accounted for except for those with very high frequencies (625
and 1840 Hz).


title: Astrophysics of Strange Matter

abstract:
  The QCD phase transition has important consequences in the context of both
the early universe as well as compact stars. Such transitions are being studied
for high temperature and small chemical potential scenario in the laboratory.
There are also plans to study systems with large chemical potential and small
temperatures. Here we have reviewed the role of strange quark matter and the
phase transition in all the above scenarios.


title: Dark energy, inflation and dark matter from modified F(R) gravity

abstract:
  We review modified $F(R)$ gravity as realistic candidate to describe the
observable universe expansion history. We show that recent cosmic acceleration,
radiation/matter-dominated epoch and inflation could be realized in the
framework of $F(R)$-gravity in the unified way. For some viable classes of
$F(R)$-gravity, the Newton law is respected and there is no so-called matter
instability (the very heavy positive mass for additional scalar degree of
freedom is generated). The reconstruction program in modified gravity is also
reviewed and it is demonstrated that {\it any} time-evolution of the universe
expansion could be realized in $F(R)$-gravity. These models remain to be
realistic also in the presence of non-minimal gravitational coupling with usual
matter. It is shown that same model which passes local tests and predicts the
unification of inflation with cosmic acceleration also describes dark matter
thanks to presence of additional scalar degree of freedom and chameleon
mechanism.


title: Measurement of top quark properties at D0

abstract:
  We present a summary of the measurements of the top quark production and
decay properties performed by the D0 experiment at the Fermilab Tevatron
proton-antiproton collider at sqrt{s}=1.96 TeV using 1 fb-1 of data. We discuss
the first simultaneous measurement of the ratio of branching fractions, R=B(t->
Wb)/B(t->Wq), with q being a d, s, or b quark, and the top quark pair
production cross section, the first model-independent measurement of the
helicity of W bosons produced in the top quark decays, and the first
measurement of the integrated forward-backward charge asymmetry in the
production of top quark pairs.


title: Representations of SO(3) and angular polyspectra

abstract:
  We characterize the angular polyspectra, of arbitrary order, associated with
isotropic fields defined on the sphere S^2. Our techniques rely heavily on
group representation theory, and specifically on the properties of Wigner
matrices and Clebsch-Gordan coefficients. The findings of the present paper
constitute a basis upon which one can build formal procedures for the
statistical analysis and the probabilistic modelization of the Cosmic Microwave
Background radiation, which is currently a crucial topic of investigation in
cosmology. We also outline an application to random data compression and
"simulation" of Clebsch-Gordan coefficients.


title:
Generalized Reynolds ideals and derived equivalences for algebras of
  dihedral and semidihedral type

abstract:
  Generalized Reynolds ideals are ideals of the center of a symmetric algebra
over a field of positive characteristic. They have been shown by the second
author to be invariant under derived equivalences. In this paper we determine
the generalized Reynolds ideals of algebras of dihedral and semidihedral type
(as defined by Erdmann), in characteristic 2. In this way we solve some open
problems about scalars occurring in the derived equivalence classification of
these algebras.


title: Stacks in canonical RNA pseudoknot structures

abstract:
  In this paper we study the distribution of stacks in $k$-noncrossing,
$\tau$-canonical RNA pseudoknot structures ($<k,\tau> $-structures). An RNA
structure is called $k$-noncrossing if it has no more than $k-1$ mutually
crossing arcs and $\tau$-canonical if each arc is contained in a stack of
length at least $\tau$. Based on the ordinary generating function of
$<k,\tau>$-structures \cite{Reidys:08ma} we derive the bivariate generating
function ${\bf T}_{k,\tau}(x,u)=\sum_{n \geq 0} \sum_{0\leq t \leq \frac{n}{2}}
{\sf T}_{k, \tau}^{} (n,t) u^t x^n$, where ${\sf T}_{k,\tau}(n,t)$ is the
number of $<k,\tau>$-structures having exactly $t$ stacks and study its
singularities. We show that for a certain parametrization of the variable $u$,
${\bf T}_{k,\tau}(x,u)$ has a unique, dominant singularity. The particular
shift of this singularity parametrized by $u$ implies a central limit theorem
for the distribution of stack-numbers. Our results are of importance for
understanding the ``language'' of minimum-free energy RNA pseudoknot
structures, generated by computer folding algorithms.


title:
Global wellposedness and scattering for the focusing energy-critical
  nonlinear Schrodinger equations of fourth order in the radial case

abstract:
  We consider the focusing energy-critical nonlinear Schr\"odinger equation of
fourth order $iu_t+\Delta^2 u=|u|^\frac{8}{d-4}u$. We prove that if a
maximal-lifespan radial solution $u: I\times\Bbb R^d\to\mathbb{C}$ obeys
$\displaystyle\sup_{t\in I}\|\Delta u(t)\|_{2}<\|\Delta W\|_{2}$, then it is
global and scatters both forward and backward in time. Here $W$ denotes the
ground state, which is a stationary solution of the equation. In particular, if
a solution has both energy and kinetic energy less than those of the ground
state $W$ at some point in time, then the solution is global and scatters.


title: Root systems and Weyl groupoids for Nichols algebras

abstract:
  Motivated by work of Kac and Lusztig, we define a root system and a Weyl
groupoid for a large class of semisimple Yetter-Drinfeld modules over an
arbitrary Hopf algebra. The obtained combinatorial structure fits perfectly
into an existing framework of generalized root systems associated to a family
of Cartan matrices, and provides novel insight into Nichols algebras. We
demonstrate the power of our construction with new results on Nichols algebras
over finite non-abelian simple groups and symmetric groups.
  Key words: Hopf algebra, quantum group, root system, Weyl group


title:
Global wellposedness and scattering for the defocusing energy-critical
  nonlinear Schrodinger equations of fourth order in dimensions $d\geq9$

abstract:
  We consider the defocusing energy-critical nonlinear Schr\"odinger equation
of fourth order $iu_t+\Delta^2 u=-|u|^\frac{8}{d-4}u$. We prove that any finite
energy solution is global and scatters both forward and backward in time in
dimensions $d\geq9$.


title: Studies of the effect of charged hadrons on lead tungstate crystals

abstract:
  Scintillating crystals are used for calorimetry in several high-energy
physics experiments. For some of them, performance has to be ensured in
difficult operating conditions, like a high radiation environment, very large
particle fluxes and high collision rates. Results are presented here from a
thorough series of measurements concerning mainly the effect of charged hadrons
on lead tungstate. It is also shown how these results can be used to predict
the effect on crystals due to a given flux of particles.


title: Prototyping coronagraphs for exoplanet characterization with SPHERE

abstract:
  The detection and characterization of extrasolar planets with SPHERE (Spectro
Polarimetric High contrast Exoplanet REsearch) is challenging and in particular
relies on the ability of a coronagraph to attenuate the diffracted starlight.
SPHERE includes 3 instruments, 2 of which can be operated simultaneously in the
near IR from 0.95 to 1.8 microns. This requirements is extremely critical for
coronagraphy. This paper briefly introduces the concepts of 2 coronagraphs, the
Half-Wave Plate Four Quadrant Phase Masks and the Apodized Pupil Lyot
Coronagraph, prototyped within the SPHERE consortium by LESIA (Observatory of
Paris) and FIZEAU (University of Nice) respectively. Then, we present the
measurements of contrast and sensitivity analysis. The comparison with
technical specifications allows to validate the technology for manufacturing
these coronagraphs.


title:
Quantum fidelity for Gaussian states describing the evolution of open
  systems

abstract:
  Using the expression of the fidelity for the most general Gaussian quantum
states, the quantum fidelity is studied for the states of a harmonic oscillator
interacting with an environment, in particular with a thermal bath. The time
evolution of the considered system is described in the framework of the theory
of open systems based on quantum dynamical semigroups. By taking a correlated
squeezed Gaussian state as initial state, we calculate the quantum fidelity for
both undisplaced and displaced states. The time evolution of the quantum
fidelity is analyzed depending on the squeezing and correlation parameters
characterizing the initial Gaussian state and on the dissipation constant and
temperature of the thermal bath.


title: Elliptic fibrations on cubic surfaces

abstract:
  We classify elliptic fibrations birational to a nonsingular, minimal cubic
surface over a field of characteristic zero. Our proof is adapted to provide
computational techniques for the analysis of such fibrations, and we describe
an implementation of this analysis in computer algebra.


title:
End to End Simulation of AO-assisted coronagraphic differential imaging:
  estimation of performance for SPHERE

abstract:
  SPHERE (Spectro Polarimetric High contrast Exoplanet REsearch), the planet
finder instrument for the VLT is designed to study relatively bright extrasolar
giant planets around young or nearby stars. SPHERE is a set of three
instruments fed by the same AO-system, two of them share the same coronagraph.
This complex system has been modeled with Fourier Optics to investigate the
performance of the whole instrument. In turns, this end-to-end model was useful
to analyze the sensitivity to various parameters (WFE, alignment of the
coronagraph, differential aberrations) and to put some specifications on the
sub-systems. This paper presents some example of sensitivity analysis and some
contrast performance of the instruments as a function of the flux for the main
observing mode of SPHERE: the Dual Band Imaging (DBI), equivalent to the
Spectral Differential Imaging technique.


title: Anomalous Threshold as the Pivot of Feynman Amplitudes

abstract:
  Reduction techniques, Landau singularities and differential equations for
Feynman amplitudes are briefly reviewed.


title:
Comment on "Spin and Orbital Angular Momentum in Gauge Theories: Nucleon
  Spin Structure and Multipole Radiation Revisited"

abstract: This is a comment on Chen et al Letter PRL,100, 232002 (2008).


title: Structural Relations between Nested Harmonic Sums

abstract:
  We describe the structural relations between nested harmonic sums emerging in
the description of physical single scale quantities up to the 3--loop level in
renormalizable gauge field theories. These are weight {\sf w=6} harmonic sums.
We identify universal basic functions which allow to describe a large class of
physical quantities and derive their complex analysis. For the 3--loop QCD
Wilson coefficients 35 basic functions are required, whereas a subset of 15
describes the 3--loop anomalous dimensions.


title:
The Relation Between Optical beams Propagation in Free Space and in
  Strongly Nonlocal Nonlinear Media

abstract:
  The relation between optical beams propagation in strongly nonlocal nonlinear
(SNN) media and {propagation} in free space is {demonstrated using} the
technique of variable transformation. The governing equation, integral and
analytical solutions, and propagation properties in free space can be directly
transferred to their counterparts in SNN media through a one-to-one
correspondence. The one-to-one correspondence together with the Huygens-Fresnel
integral yields an efficient numerical method to describe SNN propagation. The
existence conditions and possible structures of solitons and breathers in SNN
media are described in a unified manner by comparing propagation properties in
SNN media with those in free space. The results can be employed in other
contexts in which the governing equation for the evolution of waves is
equivalent to that in SNN media, such as for quadratic graded-index media, or
for harmonically trapped Bose-Einstein condensates in the noninteracting limit.


title:
Instability criterion for oblique modes in stratified circular Couette
  flow

abstract:
  An analytical approach is carried out that provides an inviscid stability
criterion for the strato-rotational instability (in short SRI) occurring in a
Taylor-Couette system. The control parameters of the problem are the rotation
ratio $\mu$ and the radius ratio $\eta$. The study is motivated by recent
experimental \cite{legal} and numerical \cite{rudi, rudi2} results reporting
the existence of unstable modes beyond the Rayleigh line for centrifugal
instability ($\mu =\eta^2$). The modified Rayleigh criterion for stably
stratified flows provides the instability condition, $\mu<1$, while in
experiments unstable modes were never found beyond the line $\mu=\eta$. Taking
into account finite gap effects, we consider non axisymmetric perturbations
with azimuthal wavenumber $l$ in the limit $l Fr<<1$, where $Fr$ is the Froude
number. We derive a necessary condition for instability : $\mu < \mu^*$ where
$\mu^*$, a function of $\eta$, takes the asymptotic values, $\mu^* \to 1$ in
the narrow gap limit, and $\mu^* \to 2\eta^2(1+\eta)$ in the wide gap limit, in
agreement with recent numerical findings. A stronger condition, $\mu<\eta$, is
found when $\eta>0.38$, in agreement with experimental results obtained for
$\eta=0.8$. Whatever the gap size, instability is predicted for values of $\mu$
larger than the critical one, $\mu_c=\eta^2$, corresponding to centrifugal
instability.


title:
Dynamical properties across a quantum phase transition in the
  Lipkin-Meshkov-Glick model

abstract:
  It is of high interest, in the context of Adiabatic Quantum Computation, to
better understand the complex dynamics of a quantum system subject to a
time-dependent Hamiltonian, when driven across a quantum phase transition. We
present here such a study in the Lipkin-Meshkov-Glick (LMG) model with one
variable parameter. We first display numerical results on the dynamical
evolution across the LMG quantum phase transition, which clearly shows a
pronounced effect of the spectral avoided level crossings. We then derive a
phenomenological (classical) transition model, which already shows some
closeness to the numerical results. Finally, we show how a simplified quantum
transition model can be built which strongly improve the classical approach,
and shed light on the physical processes involved in the whole LMG quantum
evolution. From our results, we argue that the commonly used description in
term of Landau-Zener transitions is not appropriate for our model.


title:
Knowledge bases over algebraic models. Some notes about informational
  equivalence

abstract:
  The recent advances in knowledge base research and the growing importance of
effective knowledge management raised an important question of knowledge base
equivalence verification. This problem has not been stated earlier, at least in
a way that allows speaking about algorithms for verification of informational
equivalence, because the informal definition of knowledge bases makes formal
solution of this problem impossible. In this paper we provide an implementable
formal algorithm for knowledge base equivalence verification based on the
formal definition of knowledge base proposed by Plotkin B. and Plotkin T., and
study some important properties of automorphic equivalence of models. We also
describe the concept of equivalence and formulate the criterion for the
equivalence of knowledge bases defined over finite models. Further we define
multi-models and automorphic equivalence of models and multi-models, that is
generalization of automorphic equivalence of algebras.


title:
The Impact of Transiting Planet Science on the Next Generation of
  Direct-Imaging Planet Searches

abstract:
  Within the next five years, a number of direct-imaging planet search
instruments, like the VLT SPHERE instrument, will be coming online. To
successfully carry out their programs, these instruments will rely heavily on
a-priori information on planet composition, atmosphere, and evolution.
Transiting planet surveys, while covering a different semi-major axis regime,
have the potential to provide critical foundations for these next-generation
surveys. For example, improved information on planetary evolutionary tracks may
significantly impact the insights that can be drawn from direct-imaging
statistical data. Other high-impact results from transiting planet science
include information on mass-to-radius relationships as well as atmospheric
absorption bands. The marriage of transiting planet and direct-imaging results
may eventually give us the first complete picture of planet migration,
multiplicity, and general evolution.


title: Transfer of Gorenstein dimensions along ring homomorphisms

abstract:
  A central problem in the theory of Gorenstein dimensions over commutative
noetherian rings is to find resolution-free characterizations of the modules
for which these invariants are finite. Over local rings, this problem was
recently solved for the Gorenstein flat and the Gorenstein projective
dimensions; here we give a solution for the Gorenstein injective dimension.
Moreover, we establish two formulas for the Gorenstein injective dimension of
modules in terms of the depth invariant; they extend formulas for the injective
dimension due to Bass and Chouinard.


title: Chiral two-dimensional electron gas in a periodic magnetic field

abstract:
  We study the energy spectrum and electronic properties of two-dimensional
electron gas in a periodic magnetic field of zero average with a symmetry of
triangular lattice. We demonstrate how the structure of electron energy bands
can be changed with the variation of the field strength, so that we can start
from nearly free electron gas and then transform it continuously to a system of
essentially localized chiral electron states. We find that the electrons near
some minima of the effective potential are responsible for occurrence of
dissipationless persistent currents creating a lattice of current contours. The
topological properties of the electron energy bands are also varied with the
intensity of periodic field. We calculated the topological Chern numbers of
several lower energy bands as a function of the field. The corresponding Hall
conductivity is nonzero and, when the Fermi level lies in the gap, it is
quantized.


title: NLO QCD corrections to pp->WW+jet+X

abstract:
  We report on a calculation of the next-to-leading order QCD corrections to
the production of W-boson pairs in association with a hard jet at hadron
colliders, which is an important source of background for Higgs and new-physics
searches at the LHC. If a veto against the emission of a second hard jet is
applied, the corrections stabilize the leading-order prediction for the cross
section considerably.


title: Filaments, Collapse and Outflows in Massive Star Formation

abstract:
  We present results from our numerical simulations of collapsing massive
molecular cloud cores. These numerical calculations show that massive stars
assemble quickly with mass accretion rates exceeding 10^-3 Msol/yr and confirm
that the mass accretion during the collapsing phase is much more efficient than
predicted by selfsimilar collapse solutions, dM/dt ~ c^3/G. We find that during
protostellar assembly out of a non-turbulent core, the mass accretion reaches
20 - 100 c^3/G. Furthermore, we explore the self-consistent structure of
bipolar outflows that are produced in our three dimensional magnetized collapse
simulations. These outflows produce cavities out of which radiation pressure
can be released, thereby reducing the limitations on the final mass of massive
stars formed by gravitational collapse.
  Additional enhancement of the mass accretion rate comes from accretion along
filaments that are built up by supersonic turbulent motions. Our numerical
calculations of collapsing turbulent cores result in mass accretion rates as
high as 10^-2 Msol/yr.


title: Noncommutative Supertori in Two Dimensions

abstract:
  First we consider the deformations of superspaces with N=(1,1) and N=(2,2)
supersymmetries in two dimensions. Among these the construction of
noncommutative supertorus with odd spin structure is possible only in the case
of N=(2,2) supersymmetry broken down to N=(1,1). However, for the even spin
structures the construction of noncommutative supertorus is possible for both
N=(1,1) and N=(2,2) cases. The spin structures are realized by implementing the
translational properties along the cycles of commutative supertorus in the
operator version: Odd spin structure is realized by the translation in the
fermionic direction in the same manner as in the construction of noncommutative
torus, and even spin structures are realized with appropriate versions of the
spin angular momentum operator.


title: A note on temperature without energy - a social example

abstract:
  The concept of magnetic susceptibility in the Ising model is used to identify
the social temperature as the rate of random changes of strategy for a set of
agents playing two different strategies.


title: Gravitational waves from the Big Bounce

abstract:
  In this paper we investigate gravitational waves production during the Big
Bounce phase inspired by the Loop Quantum Cosmology. We consider the influence
of the holonomy corrections to the equation for tensor modes. We show that they
act like additional effective graviton mass, suppressing gravitational waves
creation. However, this effects can be treated perturbatively. We investigate
the simplified model without these corrections and find its exact analytical
solution. For this model we calculate a spectrum of the gravitational waves
from the Big Bounce phase. The obtained spectrum decreases to zero for the low
energy modes. Based on this observation we indicate that this effect can lead
to the low CMB multipoles suppression and gives a potential way to test Loop
Quantum Cosmology models. We also consider a scenario with a post-bounce
inflationary phase. The obtained power spectrum gives qualitative explanation
of the CMB spectra, including low multipoles suppression. This result is a
challenge to construct a consistent bounce+inflation model in the Loop Quantum
Cosmology.


title: A multidimensional grid-adaptive relativistic magnetofluid code

abstract:
  A robust second order, shock-capturing numerical scheme for multi-dimensional
special relativistic magnetohydrodynamics on computational domains with
adaptive mesh refinement is presented. The base solver is a total variation
diminishing Lax-Friedrichs scheme in a finite volume setting and is combined
with a diffusive approach for controlling magnetic monopole errors. The
consistency between the primitive and conservative variables is ensured at all
limited reconstructions and the spatial part of the four velocity is used as a
primitive variable. Demonstrative relativistic examples are shown to validate
the implementation. We recover known exact solutions to relativistic MHD
Riemann problems, and simulate the shock-dominated long term evolution of
Lorentz factor 7 vortical flows distorting magnetic island chains.


title:
On the geometry of the slice of trace--free SL(2,C)-characters of a knot
  group

abstract:
  Let K be a knot in an integral homology 3-sphere and let B denote the 2-fold
branched cover of the integral homology sphere branched along K. We construct a
map from the slice of characters with trace free along meridians in the SL(2,
C)-character variety of the knot exterior to the SL(2, C)-character variety of
2-fold branched cover B. When this map is surjective, it describes the slice as
the 2-fold branched cover over the SL(2, C)-character variety of B with
branched locus given by the abelian characters, whose preimage is precisely the
set of metabelian characters. We show that each of metabelian character can be
represented as the character of a binary dihedral representation of the knot
group. This map is shown to be surjective for all 2-bridge knots and all
pretzel knots of type (p, q, r). An extension of this framework to n-fold
branched covers is also described.


title: Atomic Biology, Electrostatics, and Ionic Channels

abstract:
  I believe an atomic biology is needed to supplement present day molecular
biology, if we are to design and understand proteins, as well as define, make,
and use them. Topics in the paper are molecular biology and atomic biology.
Electrodiffusion in the open channel. Electrodiffusion in mixed electrolytes.
Models of permeation. State Models of Permeation are Inconsistent with the
Electric Field. Making models in atomic biology. Molecular dynamics. Temporal
Limitations; Spatial Limitations; Periodic boundary conditions. Hierarchy of
models of the open channel. Stochastic Motion of the Channel. Langevin
Dynamics. Simulations of the Reaction Path: the Permion. Chemical reactions.
What was wrong? Back to the hierarchy: Occam's razor can slit your throat.
Poisson-Nernst-Planck PNP Models Flux Ratios; Pumping by Field Coupling. Gating
in channels of one conformation. Gating by Field Switching; Gating Current;
Gating in Branched Channels; Blocking. Back to the hierarchy: Linking levels.
Is there a theory? At what level will the adaptation be found? Simplicity,
evolution, and natural function.


title:
Lattice dynamical calculations of infinite layer iron oxides SrFeO2 and
  CaFeO2

abstract:
  We report extensive lattice dynamical calculations of the newly discovered
infinite-layer iron oxides SrFeO2 and CaFeO2. For SrFeO2, the parameters of the
interatomic potential have been determined to reproduce the zone-centre phonon
frequencies reported using ab-initio calculations. Further we have extended the
potential model for calculations of CaFeO2. The potential parameters are found
to be transferable between the two compounds, and are used to calculate the
phonon spectra in the whole Brillouin zone and several thermodynamic properties
for these compounds. The calculations show fair agreement with the available
experimental data of structure, thermal expansion, and mean-squared amplitudes
of the atoms.


title:
A H13CN/HN13C linelist, model atmospheres and synthetic spectra for
  carbon stars

abstract:
  A line list of vibration-rotation transitions for 13C substituted HCN is
presented. The line list is constructed using known experimental levels where
available, calculated levels and ab initio line intensities originally
calculated for the major isotopologue. Synthetic spectra are generated and
compared with observations for cool carbon star WZ Cas. It is suggested that
high resolution HCN spectra recorded near 14 micron should be particularly
sensitive to the 13C to 12C ratio.


title:
The Parikh functions of sparse context-free languages are
  quasi-polynomials

abstract:
  We prove that the Parikh map of a bounded context-free language is a box
spline. Moreover we prove that in this case, such a function is rational.


title:
Thermal properties of SmFeAs(O1-xFx) as probe of the interplay between
  electrons and phonons

abstract:
  A comparative study of thermal properties of SmFeAsO, SmFeAs(O0.93F0.07) and
SmFeAs(O0.85F0.15) samples is presented. Specific heat and thermal conductivity
show clear evidences of the spin density wave (SDW) ordering below TSDW 135 K
in undoped SmFeAsO. At low level of F-doping, SmFeAs(O0.93F0.07), SDW ordering
is suppressed and superconducting features are not yet optimally developed in
both specific heat and thermal conductivity. At optimal level of F-doping
SmFeAs(O0.85F0.15) anomalies related to the superconducting transition are well
noticeable. By a compared analysis of doped and undoped samples we conclude
that, despite F-doping modifies definitely the electronic ground state, it does
not substantially alter phonon and electron parameters, like phonon modes,
Sommerfeld coefficient, electro-phonon coupling. The analysis of the thermal
conductivity curves provides an evaluation of SDW and superconducting energy
gap, showing that phonons can suitably probe features of electronic ground
state.


title: Monte Carlo study of multiply crosslinked semiflexible polymer networks

abstract:
  We present a method to generate realistic, three-dimensional networks of
crosslinked semiflexible polymers. The free energy of these networks is
obtained from the force-extension characteristics of the individual polymers
and their persistent directionality through the crosslinks. A Monte Carlo
scheme is employed to obtain isotropic, homogeneous networks that minimize the
free energy, and for which all of the relevant parameters can be varied: the
persistence length, the contour length as well as the crosslinking length may
be chosen at will. We also provide an initial survey of the mechanical
properties of our networks subjected to shear strains, showing them to display
the expected non-linear stiffening behavior. Also, a key role for non-affinity
and its relation to order in the network is uncovered.


title: Permeation as a Diffusion Process

abstract:
  The paper shows how the diffusive movement of ions through a channel protein
can be described as a chemical reaction over an arbitrary shaped potential
barrier. The result is simple and intuitive but without approximation beyond
the electrodiffusion description of ion movement.


title:
Near threshold production of the eta meson via the quasi-free pn --> pn
  eta reaction

abstract:
  Total cross sections for the quasi-free pn --> pn eta reaction in the range
from the kinematical threshold up to 20 MeV excess energy have been determined.
At threshold they exceed corresponding cross sections for the pp --> pp eta
reaction by a factor of about three in contrast to the factor of six
established for higher excess energies. To large extent, the observed decrease
of the ratio sigma(pn --> pn eta)/sigma(pp --> pp eta) towards threshold may be
assigned to the different energy dependence of the proton-proton and
proton-neutron final state interactions.
  The experiment has been conducted using a proton beam of the cooler
synchrotron COSY and a cluster jet deuteron target. The proton-neutron
reactions were tagged by the spectator proton whose momentum was measured for
each event. Protons and neutron outgoing from the pn --> pn eta reaction have
been registered by means of the COSY-11 facility, an apparatus dedicated for
threshold meson production.


title:
Analysis of Quantum Correlation in Successive Spin Measurements,
  Classical Communication of Spin $S$ Singlet States and Quantum Nonlocality of
  two Qubit Entangled States

abstract:
  In this thesis, we study about three subjects
  1- Classical simulation of two spin-$s$ singlet correlations for all $s$
involving spin measurements,
  2- Quantum correlations in successive single spin measurements,
  3- Non locality without inequality for almost all two-qubit entangled states
based on Cabello's non locality argument.


title: Diffractive Parton Distributions from Fits with Higher Twist

abstract:
  We determine diffractive parton distributions of the proton from DGLAP based
fits to HERA data including the twist--4 contribution from longitudinal
polarized virtual photons, which is known to be important in the region of
large beta. The biggest impact of this contribution is on the diffractive gluon
distribution and on the diffractive longitudinal structure function to be
determined from HERA data.


title:
Case-deletion importance sampling estimators: Central limit theorems and
  related results

abstract:
  Case-deleted analysis is a popular method for evaluating the influence of a
subset of cases on inference. The use of Monte Carlo estimation strategies in
complicated Bayesian settings leads naturally to the use of importance sampling
techniques to assess the divergence between full-data and case-deleted
posteriors and to provide estimates under the case-deleted posteriors. However,
the dependability of the importance sampling estimators depends critically on
the variability of the case-deleted weights. We provide theoretical results
concerning the assessment of the dependability of case-deleted importance
sampling estimators in several Bayesian models. In particular, these results
allow us to establish whether or not the estimators satisfy a central limit
theorem. Because the conditions we derive are of a simple analytical nature,
the assessment of the dependability of the estimators can be verified routinely
before estimation is performed. We illustrate the use of the results in several
examples.


title: Critical velocities in two-component superfluid Bose gases

abstract:
  On the ground of the Landau criterion we study the behavior of critical
velocities in a superfluid two-component Bose gas. It is found that under
motion of the components with different velocities the velocity of each
component should not be lower than a minimum phase velocity of elementary
excitations (s_). The Landau criterion yields a relation between the critical
velocities of the components (v_{c1}, v_{c2}). The velocity of one or even both
components may exceed s_. The maximum value of the critical velocity of a given
component can be reached when the other component does not move. The approach
is generalized for a two-component condensate confined in a cylindrical
harmonic potential.
  PACS numbers: 03.75.Kk,03.75.Mn


title: Liquid-liquid interfacial tension of electrolyte solutions

abstract:
  It is theoretically shown that the excess liquid-liquid interfacial tension
between two electrolyte solutions as a function of the ionic strength I behaves
asymptotically as O(- I^0.5) for small I and as O(+- I) for large I. The former
regime is dominated by the electrostatic potential due to an unequal
partitioning of ions between the two liquids whereas the latter regime is
related to a finite interfacial thickness. The crossover between the two
asymptotic regimes depends sensitively on material parameters suggesting that,
depending on the actual system under investigation, the experimentally
accessible range of ionic strengths can correspond to either the small or the
large ionic strength regime. In the limiting case of a liquid-gas surface where
ion partitioning is absent, the image chage interaction can dominate the
surface tension for small ionic strength I such that an Onsager-Samaras
limiting law O(- I ln(I)) is expected. The proposed picture is consistent with
more elaborate models and published measurements.


title: The very massive X-ray bright binary system Wack 2134 (= WR 21a)

abstract:
  From the radial velocities of the N IV 4058 and He II 4686 emission lines,
and the N V 4604-20 absorption lines, determined in digital spectra, we report
the discovery that the X-ray bright emission line star Wack 2134 (= WR 21a) is
a spectroscopic binary system with an orbital period of $31.673\pm0.002$ days.
With this period, the N IV and He II emission and N V absorption lines, which
originate in the atmosphere of the primary component, define a rather eccentric
binary orbit (e=0.64$\pm$0.03). The radial velocity variations of the N V
absorptions have a lower amplitude than those of the He II emission. Such a
behaviour of the emission line radial velocities could be due to distortions
produced by a superimposed absorption component from the companion. High
resolution echelle spectra observed during the quadrature phases of the binary
show H and He II absorptions of both components with a radial velocity
difference of about 541 km/s. From this difference, we infer quite high values
of the minimum masses, of about 87Mo and 53Mo for the primary and secondary
components, respectively, if the radial velocity variations of the He II
emission represent the true orbit of the primary. No He I absorption lines are
observed in our spectra. Thus, the secondary component in the Wack2134 binary
system appears to be an early O type star. From the presence of H, He II and N
V absorptions, and N IV and C IV emissions, in the spectrum of the primary
component, it most clearly resembles those of Of/WNLha type stars.


title: Conference Summary

abstract:
  This first Subaru international conference has highlighted the remarkably
diverse and significant contributions made using the 8.2m Subaru telescope by
both Japanese astronomers and the international community. As such, it serves
as a satisfying tribute to the pioneering efforts of Professors Keiichi Kodaira
and Sadanori Okamura whose insight and dedication is richly rewarded. Here I
try to summarize the recent impact of wide field science in extragalactic
astronomy and cosmology and take a look forward to the key questions we will
address in the near future.


title:
Quasi-periodic oscillations as global hydrodynamic modes in the boundary
  layers of viscous accretion disks

abstract:
  The observational characteristics of quasi-periodic oscillations (QPOs) from
accreting neutron stars strongly indicate the oscillatory modes in the
innermost regions of accretion disks as a likely source of the QPOs. The inner
regions of accretion disks around neutron stars can harbor very high frequency
modes related to the radial epicyclic frequency $\kappa $. The degeneracy of
$\kappa $ with the orbital frequency $\Omega $ is removed in a non-Keplerian
boundary or transition zone near the magnetopause between the disk and the
compact object. We show, by analyzing the global hydrodynamic modes of long
wavelength in the boundary layers of viscous accretion disks, that the fastest
growing mode frequencies are associated with frequency bands around $\kappa $
and $\kappa \pm \Omega $. The maximum growth rates are achieved near the radius
where the orbital frequency $\Omega $ is maximum. The global hydrodynamic
parameters such as the surface density profile and the radial drift velocity
determine which modes of free oscillations will grow at a given particular
radius in the boundary layer. In accordance with the peak separation between
kHz QPOs observed in neutron-star sources, the difference frequency between two
consecutive bands of the fastest growing modes is always related to the spin
frequency of the neutron star. This is a natural outcome of the boundary
condition imposed by the rotating magnetosphere on the boundary region of the
inner disk.


title:
How to simulate the Universe in a box? Testing modified gravity with a
  N-body simulation code

abstract:
  In this paper we present preliminary results from cosmological simulations of
modified gravity in the dark matter sector. Our results show improvements over
standard cold dark matter cosmology. The abundance of low-mass haloes in the
modified gravity model fit observations better than the conventional theory,
while the differences of the modified density fluctuation power spectrum
differs from the standard, $\Lambda$CDM power spectrum are small enough to make
these two models observationally indistinguishable at large scales.


title:
Physical behavior of a system representing a particle trapped in a box
  having flexible size

abstract:
  A critical study of the wave mechanics of a particle trapped in a 1-D box
having infinite potential walls and small flexibility in its size reveals its
several important and hither to unknown aspects which could be relevant for
better understanding of systems like quantum -dot/wire/well. Since most of
these aspects arise from the zero-point force coming into operation when the
particle occupies its ground state in the box, they are expected to have great
significance at low temperatures. To demonstrate this we briefly analyze some
important aspects of an electron bubble in liquid helium and its nano-droplets.


title:
Gauging the twisted Poincare symmetry as noncommutative theory of
  gravitation

abstract:
  Einstein's Theory of General Relativity was formulated as a gauge theory of
Lorentz symmetry by Utiyama in 1956, while the Einstein-Cartan gravitational
theory was formulated by Kibble in 1961 as the gauge theory of Poincare
transformations. In a noncommutative space-time with canonical commutation
relations between the coordintes, Lorentz symmetry is violated and field
theories constructed on such space-times have instead the so-called twisted
Poincare invariance. In this paper a gauge theory formulation of noncommutative
gravity is proposed based on the twisted Poincare symmetry together with the
requirement of covariance under the general coordinate transformations, an
essential ingredient of the theory of general relativity. The advantages of
such a formulation as well as the related problems are discussed and possible
ways out are outlined.


title:
Free and constrained symplectic integrators for numerical general
  relativity

abstract:
  We consider symplectic time integrators in numerical General Relativity and
discuss both free and constrained evolution schemes. For free evolution of
ADM-like equations we propose the use of the Stoermer-Verlet method, a standard
symplectic integrator which here is explicit in the computationally expensive
curvature terms. For the constrained evolution we give a formulation of the
evolution equations that enforces the momentum constraints in a holonomically
constrained Hamiltonian system and turns the Hamilton constraint function from
a weak to a strong invariant of the system. This formulation permits the use of
the constraint-preserving symplectic RATTLE integrator, a constrained version
of the Stoermer-Verlet method.
  The behavior of the methods is illustrated on two effectively 1+1-dimensional
versions of Einstein's equations, that allow to investigate a perturbed
Minkowski problem and the Schwarzschild space-time. We compare symplectic and
non-symplectic integrators for free evolution, showing very different numerical
behavior for nearly-conserved quantities in the perturbed Minkowski problem.
Further we compare free and constrained evolution, demonstrating in our
examples that enforcing the momentum constraints can turn an unstable free
evolution into a stable constrained evolution. This is demonstrated in the
stabilization of a perturbed Minkowski problem with Dirac gauge, and in the
suppression of the propagation of boundary instabilities into the interior of
the domain in Schwarzschild space-time.


title:
Evidence for Lattice Effects at the Charge-Ordering Transition in
  (TMTTF)$_2$X

abstract:
  High-resolution thermal expansion measurements have been performed for
exploring the mysterious "structureless transition" in (TMTTF)$_{2}$X (X =
PF$_{6}$ and AsF$_{6}$), where charge ordering at $T_{CO}$ coincides with the
onset of ferroelectric order. Particularly distinct lattice effects are found
at $T_{CO}$ in the uniaxial expansivity along the interstack
$\textbf{\textit{c*}}$-direction. We propose a scheme involving a charge
modulation along the TMTTF stacks and its coupling to displacements of the
counteranions X$^{-}$. These anion shifts, which lift the inversion symmetry
enabling ferroelectric order to develop, determine the 3D charge pattern
without ambiguity. Evidence is found for another anomaly for both materials at
$T_{int}$ $\simeq$ 0.6 $\cdot$ $T_{CO}$ indicative of a phase transition
related to the charge ordering.


title:
Critical currents and giant non-dissipative drag for superfluid
  electron-hole pairs in quantum Hall multilayers

abstract:
  Superfluid properties of electron-hole pairs in a quantum Hall four-layer
system are investigated. The system is considered as a solid state realization
of a two-component superfluid Bose gas with dipole-dipole interaction. One
superfluid component is formed in the top bilayer and the other component - in
the bottom one. We obtain the dispersion equation for the collective mode
spectrum and compute the critical parameters (the critical interlayer distance
and the critical currents) versus the filling factor. We find that the critical
currents of the components depend on each other. The maximum critical current
of a given component can be reached if the current of the other component is
equal to zero. The non-dissipative drag effect between the components is
studied. It is shown that in the system considered the drag factor is very
large. Under appropriate conditions it can be about 10 per sent, that is at
least in three order larder than one predicted for two-component atomic Bose
gases.


title: Field dependence of the thermopower of CeNiSn

abstract:
  Previously measured thermopower data of CeNiSn exhibit a significant sample
dependence and non-monotonous behavior in magnetic fields. In this paper we
demonstrate that the measured thermopower S(T) may contain a contribution from
the huge Nernst coefficient of the compound, even in moderate fields of 2 T. A
correction for this effect allows to determine the intrinsic field dependence
of S(T). The observed thermopower behavior can be understood from Zeeman
splitting of a V-shaped pseudogap in magnetic fields.


title:
The ECLAIRs telescope onboard the SVOM mission for gamma-ray burst
  studies

abstract:
  The X- and gamma-ray telescope ECLAIRs onboard the future mission for
gamma-ray burst studies SVOM (Space-based multi-band astronomical Variable
Objects Monitor) is foreseen to operate in orbit from 2013 on. ECLAIRs will
provide fast and accurate GRB triggers to other onboard telescopes, as well as
to the whole GRB community, in particular ground-based follow-up telescopes.
With its very low energy threshold ECLAIRs is particularly well suited for the
detection of highly redshifted GRB. The ECLAIRs X- and gamma-ray imaging camera
(CXG), used for GRB detection and localization, is combined with a soft X-ray
telescope (SXT) for afterglow observations and position refinement. The CXG is
a 2D-coded mask imager with a 1024 cm$^2$ detection plane made of 80$\times$80
CdTe pixels, sensitive from 4 to 300 keV, with imaging capabilities up to about
120 keV and a localization accuracy better than 10 arcmin. The CXG permanently
observes a 2 sr-wide field of the sky and provides photon data to the onboard
science and triggering unit (UTS) which detects GRB by count-rate increases or
by the appearance of a new source in cyclic sky images. The SXT is a mirror
focusing X-ray telescope operating from 0.3 to 2 keV with a sensitivity of 1
mCrab for 100 s observations. The spacecraft slews within $\simeq$3 min in
order to place the GRB candidate into the 23$\times$23 arcmin$^2$ field of view
of the SXT, after which it refines the GRB position to about 10 arcsec. GRB
alerts are transmitted to ground-observers within tens of seconds via a VHF
network and all detected photons are available hours later for detailed
analysis. In this paper we present the ECLAIRs concepts, with emphasis on the
expected performances.


title: SVOM pointing strategy: how to optimize the redshift measurements?

abstract:
  The Sino-French SVOM mission (Space-based multi-band astronomical Variable
Objects Monitor) has been designed to detect all known types of gamma-ray
bursts (GRBs) and to provide fast and reliable GRB positions. In this study we
present the SVOM pointing strategy which should ensure the largest number of
localized bursts allowing a redshift measurement. The redshift measurement can
only be performed by large telescopes located on Earth. The best scientific
return will be achieved if we are able to combine constraints from both space
segment (platform and payload) and ground telescopes (visibility).


title: The role of jets in the formation of planets, stars, and galaxies

abstract:
  Astrophysical jets are associated with the formation of young stars of all
masses, stellar and massive black holes, and perhaps even with the formation of
massive planets. Their role in the formation of planets, stars, and galaxies is
increasingly appreciated and probably reflects a deep connection between the
accretion flows - by which stars and black holes may be formed - and the
efficiency by which magnetic torques can remove angular momentum from such
flows. We compare the properties and physics of jets in both non-relativistic
and relativistic systems and trace, by means of theoretical argument and
numerical simulations, the physical connections between these different
phenomena. We discuss the properties of jets from young stars and black holes,
give some basic theoretical results that underpin the origin of jets in these
systems, and then show results of recent simulations on jet production in
collapsing star-forming cores as well as from jets around rotating Kerr black
holes.


title:
XMM-Newton X-ray and Optical Monitor far UV observations of NGC 7070A
  and ESO 2400100 shell galaxies

abstract:
  We present XMM-Newton X-ray observations of two shell galaxies, NGC 7070A and
ESO 2400100, and far UV observations obtained with the Optical Monitor for
these and for an additional shell galaxy, NGC 474, for which we also have near
and far UV data from GALEX. We aim at gaining insight on the overall evolution
traced by their star formation history and by their hot gas content. The X-ray
and the far UV data are used to derive their X-ray spatial and spectral
characteristics and their UV luminosity profiles. We use models developed ad
hoc to investigate the age of the last episode of star formation from the (UV -
optical) colors and line strength indices. The X-ray spatial and spectral
analysis show significant differences in the two objects. A low luminosity
nuclear source is the dominant component in NGC 7070A log L_X=41.7 erg s^{-1}
in the 2-10 keV band. In ESO 2400100, the X-ray emission is due to a low
temperature plasma with a contribution from the collective emission of
individual sources. In the Optical Monitor image ESO 2400100 shows a double
nucleus, one bluer than the other. This probably results from a very recent
star formation event in the northern nuclear region. The extension of the UV
emission is consistent with the optical extent for all galaxies, at different
degrees of significance in different filters. The presence of the double
nucleus, corroborated by the (UV - optical) colors and line strength indices
analysis, suggests that ESO 2400100 is accreting a faint companion. We explore
the evolution of the X-ray luminosity during accretion processes with time. We
discuss the link between the presence of gas and age, since gas is detected
either before coalescence or several Gyr (>3) after (Abridged).


title:
Novel structural features of CDK inhibition revealed by an ab initio
  computational method combined with dynamic simulations

abstract:
  The rational development of specific inhibitors for the ~500 protein kinases
encoded in the human genome is impeded by a poor understanding of the
structural basis for the activity and selectivity of small molecules that
compete for ATP binding. Combining classical dynamic simulations with a novel
ab initio computational approach linear-scalable to molecular interactions
involving thousands of atoms, we have investigated the binding of five distinct
inhibitors to the cyclin-dependent kinase CDK2. We report here that
polarization and dynamic hydrogen bonding effects, so far undetected by
crystallography, affect both their activity and selectivity. The effects arise
from the specific solvation patterns of water molecules in the ATP binding
pocket or the intermittent formation of hydrogen bonds during the dynamics of
CDK/inhibitor interactions and explain the unexpectedly high potency of certain
inhibitors such as
3-(3H-imidazol-4-ylmethylene)-5-methoxy-1,3-dihydro-indol-2-one (SU9516). The
Lys89 residue in the ATP-binding pocket of CDK2 is observed to form temporary
hydrogen bonds with the three most potent inhibitors. This residue is replaced
in CDK4 by Thr89, whose shorter side-chain cannot form similar bonds,
explaining the relative selectivity of the inhibitors for CDK2. Our results
provide a generally applicable computational method for the analysis of
biomolecular structures and reveal hitherto unrecognized features of the
interaction between protein kinases and their inhibitors


title: New aspects of leptogenesis bounds

abstract:
  We present a general analysis that reveals new aspects of the leptogenesis
bounds on neutrino masses and on the reheat temperature of the Universe. After
revisiting a known effect coming from an unbounded term in the total CP
asymmetry, we show that an unbounded term in the flavored CP asymmetries has a
stronger impact. It relaxes the lower bound on the reheat temperature down to
10^8 GeV for (M_2-M_1)/M_1=O(1-100) and for a mild tuning of the parameters in
the see-saw orthogonal matrix. We also consider the effect of the Higgs
asymmetry, showing that it lowers the upper bound on the neutrino masses in the
so-called fully flavored regime where classic Boltzmann equations can be used.
Imposing independence of the initial conditions contributes to lower the upper
bound on neutrino masses as well. We study the conditions for the validity of
the usual N_1-dominated scenario and for the applicability of the lower bound
on the lightest right-handed (RH) neutrino mass M_1. We find that except for
the two effective RH neutrino scenario, recovered for M_3 >>10^14 GeV, and for
values M_2 < O(10^11 GeV), the final asymmetry is more naturally dominated by
the contribution from N_2-decays. Finally, we confirm in a general way that
going beyond the hierarchical limit, the effect of washout addition makes the
lower bound on M_1 more stringent for (M_2-M_1)/M_1=O(0.1).


title:
Modeling solutions with jumps for rate-independent systems on metric
  spaces

abstract:
  Rate-independent systems allow for solutions with jumps that need additional
modeling. Here we suggest a formulation that arises as limit of viscous
regularization of the solutions in the extended state space. Hence, our
parametrized metric solutions of a rate-independent system are absolutely
continuous mappings from a parameter interval into the extended state space.
Jumps appear as generalized gradient flows during which the time is constant.
The closely related notion of BV solutions is developed afterwards. Our
approach is based on the abstract theory of generalized gradient flows in
metric spaces, and comparison with other notions of solutions is given.


title: Renormalization group method based on the ionization energy theory

abstract:
  Proofs are developed to explicitly show that the ionization energy theory
(IET) is a renormalized theory, which mathematically exactly satisfies the
renormalization group formalisms developed by Gell-Mann-Low, Shankar and
Zinn-Justin. However, the cutoff parameter for IET relies on the energy-level
spacing, instead of lattice spacing in \textbf{k}-space. Subsequently, we apply
the earlier proofs to prove that the mathematical structure of the
ionization-energy dressed electron-electron screened Coulomb potential is
exactly the same as the ionization-energy dressed electron-phonon interaction
potential. The latter proof is proven by means of the second-order
time-independent perturbation theory with the heavier effective mass condition,
as required by the electron-electron screened Coulomb potential. The outcome of
this proof is that we can derive the heat capacity and the Debye frequency as a
function of ionization energy, which can be applied in strongly correlated
matter and nanostructures.


title: Extended $5d$ Seiberg-Witten Theory and Melting Crystal

abstract:
  We study an extension of the Seiberg-Witten theory of $5d$ $\mathcal{N}=1$
supersymmetric Yang-Mills on $\mathbb{R}^4 \times S^1$. We investigate
correlation functions among loop operators. These are the operators analogous
to the Wilson loops encircling the fifth-dimensional circle and give rise to
physical observables of topological-twisted $5d$ $\mathcal{N}=1$ supersymmetric
Yang-Mills in the $\Omega$ background. The correlation functions are computed
by using the localization technique. Generating function of the correlation
functions of U(1) theory is expressed as a statistical sum over partitions and
reproduces the partition function of the melting crystal model with external
potentials. The generating function becomes a $\tau$ function of 1-Toda
hierarchy, where the coupling constants of the loop operators are interpreted
as time variables of 1-Toda hierarchy. The thermodynamic limit of the partition
function of this model is studied. We solve a Riemann-Hilbert problem that
determines the limit shape of the main diagonal slice of random plane
partitions in the presence of external potentials, and identify a relevant
complex curve and the associated Seiberg-Witten differential.


title: Gamma Ray Burst Central Engines

abstract:
  I review aspects of the theory of long-duration gamma-ray burst (GRB) central
engines. I focus on the requirements of any model; these include the angular
momentum of the progenitor, the power, Lorentz factor, asymmetry, and duration
of the flow, and both the association and the non-association with bright
supernovae. I compare and contrast the collapsar and millisecond proto-magnetar
models in light of these requirements. The ability of the latter model to
produce a flow with Lorentz factor ~100 while simultaneously maintaining a
kinetic luminosity of ~10^50 ergs/s for a timescale of ~10-100 s is emphasized.


title:
Strain-Control of the magnetic anisotropy in (Ga,Mn)(As,P) ferromagnetic
  semiconductor layers

abstract:
  A small fraction of phosphorus (up to 10 %) was incorporated in ferromagnetic
(Ga,Mn)As epilayers grown on a GaAs substrate. P incorporation allows reducing
the epitaxial strain or even change its sign, resulting in strong modifications
of the magnetic anisotropy. In particular a reorientation of the easy axis
toward the growth direction is observed for high P concentration. It offers an
interesting alternative to the metamorphic approach, in particular for
magnetization reversal experiments where epitaxial defects stongly affect the
domain wall propagation.


title: Detection of cellular aging in a Galton-Watson process

abstract:
  We consider the bifurcating Markov chain model introduced by Guyon to detect
cellular aging from cell lineage. To take into account the possibility for a
cell to die, we use an underlying Galton-Watson process to describe the
evolution of the cell lineage. We give in this more general framework a weak
law of large number, an invariance principle and thus fluctuation results for
the average over one generation or up to one generation. We also prove the
fluctuations over each generation are independent. Then we present the natural
modifications of the tests given by Guyon in cellular aging detection within
the particular case of the auto-regressive model.


title: The Ultimatum Game in Complex Networks

abstract:
  We address the problem of how cooperative (altruistic-like) behavior arises
in natural and social systems by analyzing an ultimatum game in complex
networks. Specifically, three types of players are considered: (a) empathetic,
whose aspiration level and offer are equal, (b) pragmatic, who do not
distinguish between the different roles and aim to obtain the same benefit, and
(c) agents whose aspiration level and offer are independent. We analyze the
asymptotic behavior of pure populations on different topologies using two kinds
of strategic update rules. Natural selection, which relies on replicator
dynamics, and Social Penalty, inspired in the Bak-Sneppen dynamics, in which
players are subjected to a social selection rule penalizing not only the less
fitted individuals, but also their first neighbors. We discuss the emergence of
fairness in the different settings and network topologies.


title: Quantum fluctuations in the image of a Bose gas

abstract:
  We analyze the information content of density profiles for an ultracold Bose
gas of atoms and extract resolution limits for observables contained in these
images. Our starting point is density correlations that we compute within the
Bogoliubov approximation, taking into account quantum and thermal fluctuations
beyond mean-field theory. This provides an approximate way to construct the
joint counting statistics of atoms in an array of pixels covering the gas. We
derive the Fisher information of an image and the associated Cramer-Rao
sensitivity bound for measuring observables contained in the image. We
elaborate on our recent study on position measurements of a dark soliton
[Negretti et al., Phys. Rev. A 77, 043606 (2008)] where a sensitivity scaling
with the atomic density as n^{-3/4} was found. We discuss here a wider class of
soliton solutions and present a detailed analysis of the Bogoliubov excitations
and the gapless (Goldstone) excitation modes. These fluctuations around the
mean field contribute to the noise in the image, and we show how they can
actually improve the ability to locate the position of the soliton.


title: Localized states in sheared electroconvection

abstract:
  Electroconvection in a thin, sheared fluid film displays a rich sequence of
bifurcations between different flow states as the driving voltage is increased.
We present a numerical study of an annular film in which a radial potential
difference acts on induced surface charges to drive convection. The film is
also sheared by independently rotating the inner edge of the annulus. This
simulation models laboratory experiments on electroconvection in sheared
smectic liquid crystal films. The applied shear competes with the electrical
forces, resulting in oscillatory and strongly subcritical bifurcations between
localized vortex states close to onset. At higher forcing, the flow becomes
chaotic via a Ruelle-Takens-Newhouse scenario. The simulation allows flow
visualization not available in the physical experiments, and sheds light on
previously observed transitions in the current-voltage characteristics of
electroconvecting smectic films.

categories: nlin.PS cond-mat.soft nlin.CD physics.flu-dyn


title: On the predictive power of Local Scale Invariance

abstract:
  Local Scale Invariance (LSI) is a theory for anisotropic critical phenomena
designed in the spirit of conformal invariance. For a given representation of
its generators it makes non-trivial predictions about the form of universal
scaling functions. In the past decade several representations have been
identified and the corresponding predictions were confirmed for various
anisotropic critical systems. Such tests are usually based on a comparison of
two-point quantities such as autocorrelation and response functions. The
present work highlights a potential problem of the theory in the sense that it
may predict any type of two-point function. More specifically, it is argued
that for a given two-point correlator it is possible to construct a
representation of the generators which exactly reproduces this particular
correlator. This observation calls for a critical examination of the predictive
content of the theory.


title: Dynamically assisted Schwinger mechanism

abstract:
  We study electron-positron pair creation {from} the Dirac vacuum induced by a
strong and slowly varying electric field (Schwinger effect) which is
superimposed by a weak and rapidly changing electromagnetic field (dynamical
pair creation). In the sub-critical regime where both mechanisms separately are
strongly suppressed, their combined impact yields a pair creation rate which is
{dramatically} enhanced. Intuitively speaking, the strong electric field lowers
the threshold for dynamical particle creation -- or, alternatively, the fast
electromagnetic field generates additional seeds for the Schwinger mechanism.
These findings could be relevant for planned ultra-high intensity lasers.


title: Holographic renormalization for coincident Dp-branes

abstract:
  We consider holographic renormalization for the decoupling limit of
coincident Dp-branes. We truncate the theory to the supergravity sector which
is homogeneous on the (8-p)-sphere and carries only RR electric (p+2)-flux,
leaving a graviton and two scalar degrees of freedom associated to the dilaton
and the sphere radius. We non-linearly construct the asymptotic graviton and
dilaton deformations - the analog of the Graham-Fefferman expansion for AdS/CFT
- and compute counterterms to give a finite renormalized bulk action and dual
one point functions. Restricting to linear deformations we find additional
counterterms to include the remaining sphere deformations which strongly deform
the asymptotic behaviour.


title:
Fourth-order ordinary differential equation obtained by similarity
  reduction of the modifed Sawada-Kotera equation

abstract:
  We study a one-parameter family of the fourth-order ordinary differential
equations obtained by similarity reduction of the modifed Sawada-Kotera
equation. We show that the birational transformations take this equation to the
polynomial Hamiltonian system in dimension four. We make this polynomial
Hamiltonian from the viewpoint of accessible singularity and local index. We
also give its symmetry and holomorphy conditions. These properties are new.
Moreover, we introduce a symmetric form in dimension five for this Hamiltonian
system by taking the two invariant divisors as the dependent variables. Thanks
to the symmetric form, we show that this system admits the affine Weyl group
symmetry of type $A_2^{(2)}$ as the group of its B{\"a}cklund transformations.


title: Defining planets by a generating function

abstract:
  A law of semi-major axes in the Solar system is described. The proposed law
is recommended as an additional criterion for planet definition as it
represents a generating function of planetary distances.


title: The non-dipolar magnetic fields of accreting T Tauri stars

abstract:
  Models of magnetospheric accretion on to classical T Tauri stars often assume
that stellar magnetic fields are simple dipoles. Recently published surface
magnetograms of BP Tau and V2129 Oph have shown, however, that their fields are
more complex. The magnetic field of V2129 Oph was found to be predominantly
octupolar. For BP Tau the magnetic energy was shared mainly between the dipole
and octupole field components, with the dipole component being almost four
times as strong as that of V2129 Oph. From the published surface maps of the
photospheric magnetic fields we extrapolate the coronal fields of both stars,
and compare the resulting field structures with that of a dipole. We consider
different models where the disc is truncated at, or well-within, the Keplerian
corotation radius. We find that although the structure of the surface magnetic
field is particularly complex for both stars, the geometry of the larger scale
field, along which accretion is occurring, is somewhat simpler. However, the
larger scale field is distorted close to the star by the stronger field
regions, with the net effect being that the fractional open flux through the
stellar surface is less than would be expected with a dipole magnetic field
model. Finally, we estimate the disc truncation radius, assuming that this
occurs where the magnetic torque from the stellar magnetosphere is comparable
to the viscous torque in the disc.


title:
Growth and characterization of A_{1-x}K_xFe_2As_2 (A = Ba, Sr) single
  crystals with x=0 - 0.4

abstract:
  Single crystals of A$_{1-x}$K$_x$Fe$_2$As$_2$ (A=Ba, Sr) with high quality
have been grown successfully by FeAs self-flux method. The samples have sizes
up to 4 mm with flat and shiny surfaces. The X-ray diffraction patterns suggest
that they have high crystalline quality and c-axis orientation. The
non-superconducting crystals show a spin-density-wave (SDW) instability at
about 173 K and 135 K for Sr-based and Ba-based compound, respectively. After
doping K as the hole dopant into the BaFe$_2$As$_2$ system, the SDW transition
is smeared, and superconducting samples with the compound of
Ba$_{1-x}$K$_x$Fe$_2$As$_2$ (0 $< x \leqslant$ 0.4) are obtained. The
superconductors characterized by AC susceptibility and resistivity measurements
exhibit very sharp superconducting transition at about 36 K, 32 K, 27 K and 23
K for x= 0.40,0.28,0.25 and 0.23, respectively.


title: P-spectrum and collapsing of connected sums, calculus of the limit

abstract:
  The goal of the paper is to calculate the limit sectrum of the Hodge-Laplace
operator under the perturbation of collapse of one part of a connected sum.
This gives some new results concerning the 'conformal spectrum' on differential
forms.


title: Polarization-Mixing in Optical Lattices with Uniaxial Anisotropy

abstract:
  We study optical excitations of an ultracold gas in an optical lattice in the
Mott insulator case and with anisotropic properties. The anisotropy is induced
by an oriented transition dipole generated by optical pumping and external
static fields, and is of the type of uniaxial crystals. Within a cavity, the
electronic excitations and the cavity photons of both TE and TM polarizations
are coherently mixed to form two polariton branches. Also a photonic branch
appears which decouples from the electronic transitions. The photon
polarization mixing can be observed by linear optical spectra. For example, for
an incident field of TE polarization we obtain TE and TM transmitted and
reflected fields. Also we calculate the phase shift in the TE and TM
transmitted and reflected fields relative to the incident field phase, which
lead to polarization rotations.


title: Unconstrained Recursive Importance Sampling

abstract:
  We propose an unconstrained stochastic approximation method of finding the
optimal measure change (in an a priori parametric family) for Monte Carlo
simulations. We consider different parametric families based on the Girsanov
theorem and the Esscher transform (or exponential-tilting). In a
multidimensional Gaussian framework, Arouna uses a projected Robbins-Monro
procedure to select the parameter minimizing the variance. In our approach, the
parameter (scalar or process) is selected by a classical Robbins-Monro
procedure without projection or truncation. To obtain this unconstrained
algorithm we intensively use the regularity of the density of the law without
assume smoothness of the payoff. We prove the convergence for a large class of
multidimensional distributions and diffusion processes. We illustrate the
effectiveness of our algorithm via pricing a Basket payoff under a
multidimensional NIG distribution, and pricing a barrier options in different
markets.


title:
The occurrence of a triple -1 resonance in the standard singularity
  analysis

abstract:
  Any careful singularity analysis of the Mixmaster Universe uncovers the
instance of a triple -1 resonance. The Mixmaster Universe does not exhibit a
closed-form solution and so a correct interpretation of the meaning of the
triple -1 resonance is difficult. We provide a system of differential equations
for which both a closed-form solution and a triple -1 resonance exist.


title: Localisable moving average stable and multistable processes

abstract:
  We study a particular class of moving average processes which possess a
property called localisability. This means that, at any given point, they admit
a ``tangent process'', in a suitable sense. We give general conditions on the
kernel g defining the moving average which ensures that the process is
localisable and we characterize the nature of the associated tangent processes.
Examples include the reverse Ornstein-Uhlenbeck process and the multistable
reverse Ornstein-Uhlenbeck process. In the latter case, the tangent process is,
at each time t, a L\'evy stable motion with stability index possibly varying
with t. We also consider the problem of path synthesis, for which we give both
theoretical results and numerical simulations.


title: The concordance genus of a knot, II

abstract:
  The concordance genus of a knot K is the minimum three-genus among all knots
concordant to K. For prime knots of 10 or fewer crossings there have been three
knots for which the concordance genus was unknown. Those three cases are now
resolved. Two of the cases are settled using invariants of Levine's algebraic
concordance group. The last case depends on the use of twisted Alexander
polynomials, viewed as Casson-Gordon invariants.


title:
Quantum Jumps between Macroscopic Quantum States of a Superconducting
  Qubit Coupled to a Microscopic Two-Level System

abstract:
  We report the observation of quantum jumps between macroscopic quantum states
in a superconducting phase qubit coupled to the two-level systems in the
Josephson tunnel junction, and all key features of quantum jumps are confirmed
in the experiments. Moreover, quantum jumps can be used to calibrate such
two-level systems, which are believed to be one of the main decoherence sources
in Josephson devices.


title:
Security of quantum key distribution with bit and basis dependent
  detector flaws

abstract:
  We consider the security of the Bennett-Brassard 1984 (BB84) protocol for
Quantum Key Distribution (QKD), in the presence of bit and basis dependent
detector flaws. We suggest a powerful attack that can be used in systems with
detector efficiency mismatch, even if the detector assignments are chosen
randomly by Bob. A security proof is provided, valid for any basis dependent,
possibly lossy, linear optical imperfections in the channel/receiver/detectors.
The proof does not assume the so-called squashing detector model.


title:
Macroscopic electrostatic potentials and interactions in self-assembled
  molecular bilayers: the case of Newton black films

abstract:
  We propose a very simple but 'realistic' model of amphiphilic bilayers,simple
enough to be able to include a large number of molecules in the sample, but
nevertheless detailed enough to include molecular charge distributions,
flexible amphiphilic molecules and a reliable model of water. All these
parameters are essential in a nanoscopic scale study of intermolecular and long
range electrostatic interactions. We also propose a novel, simple and more
accurate macroscopic electrostatic field for model bilayers. This model goes
beyond the total dipole moment of the sample, which on a time average is zero
for this type of symmetrical samples, i. e., it includes higher order moments
of this macroscopic electric field. We show that by representing it with a
superposition of gaussians it can be 'analytically' integrated, and therefore
its calculation is easily implemented in a MD simulation (even in simulations
of non-symmetrical bi- or multi-layers). In this paper we test our model by
molecular dynamics simulations of Newton black films.


title:
Short note on magnetic impurities in SmFeAsO$_{1-x}$F$_x$ (x=0, 0.07)
  compounds revealed by zero-field $^{75}$As NMR

abstract:
  We have performed zero-field $^{75}$As nuclear magnetic resonance study of
SmFeAsO$_{1-x}$F$_x$ (x=0, 0.07) polycrystals in a wide frequency range at
various temperatures. $^{75}$As resonance line was found at around 265 MHz
revealing the formation of the intermetallic FeAs clusters in the new layered
superconductors. We have also demonstrated that NMR is a sensitive tool for
probing the quality of these materials.


title:
Existence of a metallic phase and upper bounds of the Hartree-Fock
  energy in the homogeneous electron gas

abstract:
  We consider the ground state of the homogeneous electron gas and we prove
that a Hartree-Fock solution, motivated by previous simulations, has lower
energy than the Fermi gas in the large density limit. This solution is a
metallic phase : the density modulation corresponds to a partially occupied
crystal (the number of sites is larger than the number of electrons).


title: Intersubband-induced spin-orbit interaction in quantum wells

abstract:
  Recently, we have found an additional spin-orbit (SO) interaction in quantum
wells with two subbands [Phys. Rev. Lett. 99, 076603 (2007)]. This new SO term
is non-zero even in symmetric geometries, as it arises from the intersubband
coupling between confined states of distinct parities, and its strength is
comparable to that of the ordinary Rashba. Starting from the $8 \times 8$ Kane
model, here we present a detailed derivation of this new SO Hamiltonian and the
corresponding SO coupling. In addition, within the self-consistent Hartree
approximation, we calculate the strength of this new SO coupling for realistic
symmetric modulation-doped wells with two subbands. We consider gated
structures with either a constant areal electron density or a constant chemical
potential. In the parameter range studied, both models give similar results. By
considering the effects of an external applied bias, which breaks the
structural inversion symmetry of the wells, we also calculate the strength of
the resulting induced Rashba couplings within each subband. Interestingly, we
find that for double wells the Rashba couplings for the first and second
subbands interchange signs abruptly across the zero bias, while the
intersubband SO coupling exhibits a resonant behavior near this symmetric
configuration. For completeness we also determine the strength of the
Dresselhaus couplings and find them essentially constant as function of the
applied bias.


title:
Localization for one-dimensional random potentials with large local
  fluctuations

abstract:
  We study the localization of wave functions for one-dimensional Schr\"odinger
Hamiltonians with random potentials $V(x)$ with short range correlations and
large local fluctuations such that $\int\D{x} \smean{V(x)V(0)}=\infty$. A
random supersymmetric Hamiltonian is also considered. Depending on how large
the fluctuations of $V(x)$ are, we find either new energy dependences of the
localization length, $\ell_\mathrm{loc}\propto{}E/\ln{E}$,
$\ell_\mathrm{loc}\propto{}E^{\mu/2}$ with $0<\mu<2$ or
$\ell_\mathrm{loc}\propto\ln^{\mu-1}E$ for $\mu>1$, or superlocalization (decay
of the wave functions faster than a simple exponential).


title: A full sky, low foreground, high resolution CMB map from WMAP

abstract:
  The WMAP satellite has made available high quality maps of the sky in five
frequency bands ranging from 22 to 94 GHz, with the main scientific objective
of studying the anisotropies of the Cosmic Microwave Background (CMB). These
maps, however, contain a mixture of emissions from various astrophysical
origins, superimposed on CMB emission. The objective of the present work is to
make a high resolution CMB map in which contamination by such galactic and
extra-galactic foregrounds, as well as by instrumental noise, is as low as
possible. The method used is an implementation of a constrained linear
combination of the channels with minimum error variance, and of Wiener
filtering, on a frame of spherical wavelets called needlets, allowing localised
filtering in both pixel space and harmonic space. We obtain a low contamination
low noise CMB map at the resolution of the WMAP W channel, which can be used
for a range of scientific studies. We obtain also a Wiener-filtered version
with minimal integrated error. The resulting CMB maps offer significantly
better rejection of galactic foregrounds than previous CMB maps from WMAP data.
They can be considered as the most precise full-sky CMB temperature maps
to-date.


title:
Superconductor - Normal and Quantum Superconductor-Insulator Transition
  at the LaAlO3/SrTiO3Interface

abstract:
  Superconductivity at the interface between the insulators LaAlO3 and SrTiO3
has been tuned with the electric field effect. The data provide evidence for a
two dimensional quantum superconductor to insulator (2D-QSI) transition. Here
we explore the compatibility of this phase transition line with
Berezinskii-Kosterlitz-Thouless (BKT) behavior and a 2D-QSI transition. In an
intermediate regime, limited by a finite size effect, we uncover remarkable
consistency with BKT- criticality, weak localization in the insulating state
and non-Drude behavior in the normal state. Our estimates for the critical
exponents of the 2D-QSI-transition, z =1 and nu=3, suggest that it belongs to
the 3D-xy universality class.


title: Efficiency of Producing Random Unitary Matrices with Quantum Circuits

abstract:
  We study the scaling of the convergence of several statistical properties of
a recently introduced random unitary circuit ensemble towards their limits
given by the circular unitary ensemble (CUE). Our study includes the full
distribution of the absolute square of a matrix element, moments of that
distribution up to order eight, as well as correlators containing up to 16
matrix elements in a given column of the unitary matrices. Our numerical
scaling analysis shows that all of these quantities can be reproduced
efficiently, with a number of random gates which scales at most as $n_q\log
(n_q/\epsilon)$ with the number of qubits $n_q$ for a given fixed precision
$\epsilon$. This suggests that quantities which require an exponentially large
number of gates are of more complex nature.


title: The modified complex Busemann-Petty problem on sections of convex bodies

abstract:
  Since the answer to the complex Busemann-Petty problem is negative in most
dimensions, it is natural to ask what conditions on the (n-1)-dimensional
volumes of the central sections of complex convex bodies with complex
hyperplanes allow to compare the n-dimensional volumes. In this article we give
necessary conditions on the section function in order to obtain an affirmative
answer in all dimensions.


title: The all loop AdS4/CFT3 Bethe ansatz

abstract:
  We propose a set of Bethe equations yielding the full asymptotic spectrum of
the AdS4/CFT3 duality proposed in arXiv:0806.1218 to all orders in the t'Hooft
coupling. These equations interpolate between the 2-loop Bethe ansatz of
Minahan and Zarembo arXiv:0806.3951 and the string algebraic curve of
arXiv:0807.0437. The several SU(2|2) symmetries of the theory seem to highly
constrain the form of the Bethe equations up to a dressing factor whose form we
also conjecture.


title:
A forward-backward splitting algorithm for the minimization of
  non-smooth convex functionals in Banach space

abstract:
  We consider the task of computing an approximate minimizer of the sum of a
smooth and non-smooth convex functional, respectively, in Banach space.
Motivated by the classical forward-backward splitting method for the
subgradients in Hilbert space, we propose a generalization which involves the
iterative solution of simpler subproblems. Descent and convergence properties
of this new algorithm are studied. Furthermore, the results are applied to the
minimization of Tikhonov-functionals associated with linear inverse problems
and semi-norm penalization in Banach spaces. With the help of
Bregman-Taylor-distance estimates, rates of convergence for the
forward-backward splitting procedure are obtained. Examples which demonstrate
the applicability are given, in particular, a generalization of the iterative
soft-thresholding method by Daubechies, Defrise and De Mol to Banach spaces as
well as total-variation based image restoration in higher dimensions are
presented.


title: The complex Busemann-Petty problem for arbitrary measures

abstract:
  The complex Busemann-Petty problem asks whether origin symmetric convex
bodies in C^n with smaller central hyperplane sections necessarily have smaller
volume. The answer is affirmative if n\leq 3 and negative if n\geq 4. In this
article we show that the answer remains the same if the volume is replaced by
an "almost" arbitrary measure. This result is the complex analogue of
Zvavitch's generalization to arbitrary measures of the original real
Busemann-Petty problem.


title:
A three-state kinetic mechanism for scaffold mediated signal
  transduction

abstract:
  Signaling events in eukaryotic cells are often guided by a scaffolding
protein. Scaffold proteins assemble multiple proteins in a spatially localized
signaling complex and exert numerous physical effects on signaling pathways. To
study these effects, we consider a minimal, three-state kinetic model of
scaffold mediated kinase activation. We first introduce and apply a path
summation technique to obtain approximate solutions to a single molecule master
equation that governs protein kinase activation. We then consider exact
numerical solutions. We comment on when this approximation is appropriate and
then use this analysis to illustrate the competition of processes occurring at
many time scales involved in signal transduction in the presence of a scaffold
protein. The findings are consistent with recent experiments and simulation
data. Our results provide a framework and offer a mechanism for understanding
how scaffold proteins can influence the shape of the waiting time distribution
of kinase activation and effectively broaden the times over which protein
kinases are activated in the course of cell signaling.


title: The redshift distribution of the X-ray background

abstract:
  The X-ray background (XRB) is produced by a large number of faint sources
distributed over a wide range of redshifts. The XRB carries information on the
spatial distribution and evolution of these sources. The goals of the paper
are: 1. to determine the redshift distribution of the soft X-ray background
photons produced by all types of extragalactic sources, in order to relate
fluctuations of the background to the large scale structures, 2. to determine
the redshift distribution of the soft XRB produced by AGN in order to calculate
the evolution of the AGN X-ray luminosity density. A set of major X-ray surveys
is used to determine the redshift distributions of the X-ray sources selected
at various flux levels. Simple analytic fits to the data allow us to determine
the smooth relationship between the redshift distribution and the source flux.
The redshift distribution of the integral XRB flux is obtained by averaging the
fits over the source counts. It is shown that the distribution of extragalactic
XRB photons in the 0.5-2 keV band is adequately represented by the function:
dn/dlog z = 5.24 z^1.52 exp(-z/0.63). The huge voids postulated to explain the
cold spots in the CMB maps create dips in the total XRB flux. However, the
expected magnitude of the effect is comparable to the fluctuation amplitude of
the XRB generated by the individual sources contributing to the background. The
cosmic evolution of the AGN X-ray luminosity density up to redshift of ~5 is
calculated in an elegant and straightforward way. Systematic uncertainties of
the present method are assessed and shown to be small. At redshift greater than
one the present results could be compared directly with some recent estimates
obtained in a standard way and the agreement between both methods is very good.


title: Comparing and interpolating distributions on manifold

abstract:
  We are interested in comparing probability distributions defined on
Riemannian manifold. The traditional approach to study a distribution relies on
locating its mean point and finding the dispersion about that point. On a
general manifold however, even if two distributions are sufficiently
concentrated and have unique means, a comparison of their covariances is not
possible due to the difference in local parametrizations. To circumvent the
problem we associate a covariance field with each distribution and compare them
at common points by applying a similarity invariant function on their
representing matrices. In this way we are able to define distances between
distributions. We also propose new approach for interpolating discrete
distributions and derive some criteria that assure consistent results. Finally,
we illustrate with some experimental results on the unit 2-sphere.


title: Zeros of Dirichlet series with periodic coefficients

abstract:
  Let $a=(a_n)_{n\ge 1}$ be a periodic sequence, $F_a(s)$ the meromorphic
continuation of $\sum_{n\ge 1} a_n/n^s$, and $N_a(\sigma_1, \sigma_2, T)$ the
number of zeros of $F_a(s)$, counted with their multiplicities, in the
rectangle $\sigma_1 < \Re s < \sigma_2$, $|\Im s | \le T$. We extend previous
results of Laurin\v{c}ikas, Kaczorowski, Kulas, and Steuding, by showing that
if $F_a(s)$ is not of the form $P(s) L_{\chi} (s)$, where $P(s)$ is a Dirichlet
polynomial and $L_{\chi}(s)$ a Dirichlet L-function, then there exists an
$\eta=\eta(a)>0$ such that for all $1/2 < \sigma_1 < \sigma_2 < 1+\eta$, we
have $c_1 T \le N_a(\sigma_1, \sigma_2, T) \le c_2 T$ for sufficiently large
$T$, and suitable positive constants $c_1$ and $c_2$ depending on $a$,
$\sigma_1$, and $\sigma_2$.


title: A resolution of the transition to turbulence paradox

abstract:
  Understanding the transition to turbulence has been impeded by a modeling
oversight


title: Performance of the combined zero degree calorimeter for CMS

abstract:
  The combined zero degree calorimeter (ZDC) is a combination of sampling
quartz/tungsten electromagnetic and hadronic calorimeters. Two identical
combined calorimeters are located in the LHC tunnel at CERN at the straight
section ~140 m on each side of the CMS interaction vertex and between the two
beam pipes. They will detect very forward photons and neutrons. ZDC information
can be used for a variety of physics measurements as well as improving the
collision centrality determination in heavy-ion collisions. Results are
presented for ZDC performance studies with the CERN SPS H2 test beam.


title:
Ion-induced electron production in tissue-like media and DNA damage
  mechanisms

abstract:
  We propose an inclusive approach for calculating characteristics of secondary
electrons produced by ions/protons in tissue-like media. This approach is based
on an analysis of the projectile's interaction with the medium on the
microscopic level. It allows us to obtain the energy spectrum and abundance of
secondary electrons as functions of the projectile kinetic energy. The physical
information obtained in this analysis is related to biological processes
responsible for the irrepearable DNA damage induced by the projectile. In
particular, we consider double strand breaks of DNA caused by secondary
electrons and free radicals, and local heating in the ion's track. The heating
may enhance the biological effectiveness of electron/free radical interactions
with the DNA and may even be considered as an independent mechanism of DNA
damage. Numerical estimates are performed for the case of carbon-ion beams. The
obtained dose-depth curves are compared with results of the MCHIT model based
on the GEANT4 toolkit.


title:
Physics of computation and light sheet concept in the measurement of
  (4+n)-dimensional spacetime geometry

abstract:
  We analyze the limits that quantum mechanics imposes on the accuracy to which
$(4+n)$-dimensional spacetime geometry can be measured. Using physics of
computation and light sheet concept we derive explicit expressions for quantum
fluctuations and explore their cumulative effects for various spacetime foam
models.


title:
From Black-Scholes and Dupire formulae to last passage times of local
  martingales. Part B : The finite time horizon

abstract:
  These notes are the second half of the contents of the course given by the
second author at the Bachelier Seminar (8-15-22 February 2008) at IHP. They
also correspond to topics studied by the first author for her Ph.D.thesis.


title: Wave Functions and Yukawa Couplings in Local String Compactifications

abstract:
  We consider local models of magnetised D7 branes in IIB string
compactifications, focussing on cases where an explicit metric can be written
for the local 4-cycle. The presence of an explicit metric allows analytic
expressions for the gauge bundle and for the chiral matter wavefunctions
through solving the Dirac and Laplace equations. The triple overlap of the
normalised matter wavefunctions generates the physical Yukawa couplings. Our
main examples are the cases of D7 branes on P1xP1 and P2. We consider both
supersymmetric and non-supersymmetric gauge backgrounds and both Abelian and
non-Abelian gauge bundles. We briefly outline potential phenomenological
applications of our results.


title: Trapping and cooling fermionic atoms into the Mott and N\'eel states

abstract:
  We perform a theoretical study of a fermionic gas with two hyperfine states
confined to an optical lattice. We derive a generic state diagram as a function
of interaction strength, particle number, and confining potential. We discuss
the central density, the double occupancy and their derivatives as probes for
the Mott state, connecting our findings to the recent experiment of J\"ordens
et al. Using entropic arguments we compare two different strategies to reach
the antiferromagnetic state in the presence of a trapping potential.