title: Cosmic Rays above the Knee

abstract:
  An overview on the present observational status and phenomenological
understanding of cosmic rays above 10^16 eV is given. Above these energies the
cosmic ray flux is expected to be gradually dominated by an extra-galactic
component. In order to investigate the nature of this transition, current
experimental activities focus on the measurement of the cosmic ray flux and
composition at the 'ankle' or 'dip' feature at several EeV. At the ultra high
energy end of the spectrum, the flux suppression above 50 EeV is now well
established by the measurements of HiRes and the Pierre Auger Observatory and
we may enter the era of charged particle astronomy.


title: The basic role of magnetic field in stellar evolution

abstract:
  Magnetic field is playing an important role at all stages of star evolution
from star formation to the endpoints. The main effects are briefly reviewed. We
also show that O-type stars have large convective envelopes, where convective
dynamo could work. There, fields in magnetostatic balance have intensities of
the order of 100 G. A few OB stars with strong polar fields (Henrichs et al.
2003a) show large N-enhancements indicating a strong internal mixing. We
suggest that the meridional circulation enhanced by an internal rotation law
close to uniform in these magnetic stars is responsible for the observed
mixing. Thus, it is not the magnetic field itself which makes the mixing, but
the strong thermal instability associated to solid body rotation. A critical
question for evolution is whether a dynamo is at work in radiative zones of
rotating stars. The Tayler-Spruit (TS) dynamo is the best candidate. We derive
some basic relations for dynamos in radiative layers. Evolutionary models with
TS dynamo show important effects: internal rotation coupling and enhanced
mixing, all model outputs being affected.


title: Neutrino cross sections and nuclear structure

abstract:
  The effects of the theoretical uncertainties in the description of
neutrino-nucleus cross sections for supernova neutrino energies are
investigated.


title:
Four- and eight-fermion interactions in a space-time with non-trivial
  topology

abstract:
  The phase structure of an eight-fermion interaction model is investigated in
a compact space-time with non-trivial topology, $M^{D-1}\otimes S^1$. The phase
boundary dividing the symmetric and the broken phase is shown as a function of
the space-time dimensions. It is found that the eight-fermion interaction does
not modify the phase boundary for the chiral symmetry breaking.


title: On the boundary of the region containing trapped surfaces

abstract:
  The boundary of the region in spacetime containing future-trapped closed
surfaces is considered. In asymptotically flat spacetimes, this boundary does
not need to be the event horizon nor a dynamical/trapping horizon. Some
properties of this boundary and its localization are analyzed, and illustrated
with examples. In particular, fully explicit future-trapped compact surfaces
penetrating into flat portions of a Vaidya spacetime are presented.


title: Effective field theory, large number of particle species, and holography

abstract:
  An effective quantum field theory (QFT) with a manifest UV/IR connection, so
as to be valid for arbitrarily large volumes, can successfully be applied to
the cosmological dark energy problem as well as the cosmological constant (CC)
problem. Motivated by recent approaches to the hierarchy problem, we develop
such a framework with a large number of particle species. When applying to
systems on the brink of experiencing a sudden collapse to a black hole, we find
that the entropy, unlike the total energy, now becomes an increasing function
of the number of field species. An internal consistency of the theory is then
used to infer the upper bound on the number of particle species, showing
consistency with the holographic Bekenstein-Hawking bound. This may thus serve
to fill in a large gap in entropy of any non-black hole configuration of matter
and the black holes. In addition, when the bound is saturated the entanglement
entropy matches the black hole entropy, thus solving the multiplicity of
species problem. In a cosmological setting, the maximum allowable number of
species becomes a function of cosmological time, reaching its minimal value in
a low-entropy post-reheating epoch.


title:
Geometric scaling: a simple preconditioner for certain linear systems
  with discontinuous coefficients

abstract:
  Linear systems with large differences between coefficients ("discontinuous
coefficients") arise in many cases in which partial differential
equations(PDEs) model physical phenomena involving heterogeneous media. The
standard approach to solving such problems is to use domain decomposition
techniques, with domain boundaries conforming to the boundaries between the
different media. This approach can be difficult to implement when the geometry
of the domain boundaries is complicated or the grid is unstructured. This work
examines the simple preconditioning technique of scaling the equations by
dividing each equation by the Lp-norm of its coefficients. This preconditioning
is called geometric scaling (GS). It has long been known that diagonal scaling
can be useful in improving convergence, but there is no study on the general
usefulness of this approach for discontinuous coefficients. GS was tested on
several nonsymmetric linear systems with discontinuous coefficients derived
from convection-diffusion elliptic PDEs with small to moderate convection
terms. It is shown that GS improved the convergence properties of restarted
GMRES and Bi-CGSTAB, with and without the ILUT preconditioner. GS was also
shown to improve the distribution of the eigenvalues by reducing their
concentration around the origin very significantly.


title: Boson stars with repulsive selfinteractions

abstract:
  The properties of compact stars made of massive bosons with a repulsive
selfinteraction mediated by vector mesons are studied within the mean-field
approximation and general relativity. We demonstrate that there exists a
scaling property for the mass-radius curve for arbitrary boson masses and
interaction strengths which results in an universal mass-radius relation. The
radius remains nearly constant for a wide range of compact star masses. The
maximum stable mass and radius of boson stars are determined by the interaction
strength and scale with the Landau mass and radius. Both, the maximum mass and
the corresponding radius increase linearly with the interaction strength so
that they can be radically different compared to the other families of boson
stars where interactions are ignored.


title:
Improved modelling of liquid GeSe$_2$: the impact of the
  exchange-correlation functional

abstract:
  The structural properties of liquid GeSe$_2$ are studied by using
first-principles molecular dynamics in conjuncton with the Becke, Lee, Yang and
Parr (BLYP) generalized gradient approximation for the exchange and correlation
energy. The results on partial pair correlation functions, coordination
numbers, bond angle distributions and partial structure factors are compared
with available experimental data and with previous first-principle molecular
dynamics results obtained within the Perdew and Wang (PW) generalized gradient
approximation for the exchange and correlation energy. We found that the BLYP
approach substantially improves upon the PW one in the case of the short-range
properties. In particular, the Ge$-$Ge pair correlation function takes a more
structured profile that includes a marked first peak due to homopolar bonds, a
first maximum exhibiting a clear shoulder and a deep minimum, all these
features being absent in the previous PW results. Overall, the amount of
tetrahedral order is significantly increased, in spite of a larger number of
Ge$-$Ge homopolar connections. Due to the smaller number of miscoordinations,
diffusion coefficients obtained by the present BLYP calculation are smaller by
at least one order of magnitude than in the PW case.


title: Scattering polarization due to light source anisotropy

abstract:
  We consider the polarization arising from scattering in an envelope
illuminated by a central anisotropic source. Spherical harmonics are used to
describe both the light source anisotropy and the envelope density distribution
functions of the scattering particles. This framework demonstrates how the net
resultant polarization arises from a superposition of three basic "shape"
functions: the distribution of source illumination, the distribution of
envelope scatterers, and the phase function for dipole scattering. Specific
expressions for the Stokes parameters and scattered flux are derived for the
case of an ellipsoidal light source inside an ellipsoidal envelope, with
principal axes that are generally not aligned. Two illustrative examples are
considered: (a) axisymmetric mass loss from a rapidly rotating star, such as
may apply to some Luminous Blue Variables, and (b) a Roche-lobe filling star in
a binary system with a circumstellar envelope. As a general conclusion, the
combination of source anisotropy with distorted scattering envelopes leads to
more complex polarimetric behavior such that the source characteristics should
be carefully considered when interpreting polarimetric data.


title: First-Principles Study on Leakage Current through Si/SiO$_2$ Interface

abstract:
  The relationship between the presence of defects at the stacking structure of
the Si/SiO$_2$ interface and leakage current is theoretically studied by
first-principles calculation. I found that the leakage current through the
interface with dangling bonds is 530 times larger than that without any
defects, which is expected to lead to dielectric breakdown. The direction of
the dangling bonds is closely related to the performance of the oxide as an
insulator. In addition, it is proved that the termination of the dangling bonds
by hydrogen atoms is effective for reducing the leakage current.


title:
Two Mode Photon Bunching Effect as Witness of Quantum Criticality in
  Circuit QED

abstract:
  We suggest a scheme to probe critical phenomena at a quantum phase transition
(QPT) using the quantum correlation of two photonic modes simultaneously
coupled to a critical system. As an experimentally accessible physical
implementation, a circuit QED system is formed by a capacitively coupled
Josephson junction qubit array interacting with one superconducting
transmission line resonator (TLR). It realizes an Ising chain in the transverse
field (ICTF) which interacts with the two magnetic modes propagating in the
TLR. We demonstrate that in the vicinity of criticality the originally
independent fields tend to display photon bunching effects due to their
interaction with the ICTF. Thus, the occurrence of the QPT is reflected by the
quantum characteristics of the photonic fields.


title: Optimal Succinctness for Range Minimum Queries

abstract:
  For a static array A of n ordered objects, a range minimum query asks for the
position of the minimum between two specified array indices. We show how to
preprocess A into a scheme of size 2n+o(n) bits that allows to answer range
minimum queries on A in constant time. This space is asymptotically optimal in
the important setting where access to A is not permitted after the
preprocessing step. Our scheme can be computed in linear time, using only n +
o(n) additional bits at construction time. In interesting by-product is that we
also improve on LCA-computation in BPS- or DFUDS-encoded trees.


title:
Renormalization group evolution of neutrino masses and mixing in the
  Type-III seesaw mechanism

abstract:
  We consider the standard model extended by heavy right handed fermions
transforming as triplets under SU(2)$_L$, which generate neutrino masses
through the Type-III seesaw mechanism. At energies below their respective mass
scales, the heavy fields get sequentially decoupled to give an effective
dimension-5 operator. Above their mass thresholds, these fields also
participate in the renormalization of the wavefunctions, masses and coupling
constants. We compute the renormalization group evolution of the effective
neutrino mass matrix in this model, with particular emphasis on the threshold
effects. The evolution equations are obtained in a basis of neutrino parameters
where all the quantities are well-defined everywhere, including at $\theta_{13}
= 0$. We also point out the important role of the threshold effects and
Majorana phases in the evolution of mixing angles through illustrative
examples.


title: Analytic continuation in two-color QCD: new results on the critical line

abstract:
  We test the method of analytic continuation from imaginary to real chemical
potential in two-color QCD, which is free from the sign problem. In particular,
we consider the analytic continuation of the critical line to real values of
the chemical potential.


title: Hardy inequalities for weighted Dirac operatos

abstract:
  An inequality of Hardy type is established for quadratic forms involving
Dirac operator and a weight $r^{-b}$ for functions in $\R^n$. The exact Hardy
constant $c_b=c_b(n)$ is found and generalized minimizers are given. The
constant $c_b$ vanishes on a countable set of $b$, which extends the known case
$n=2$, $b=0$ which corresponds to the trivial Hardy inequality in $\R^2$.
Analogous inequalities are proved in the case $c_b=0$ under constraints and,
with error terms, for a bounded domain.


title: Motility states of molecular motors engaged in a stochastic tug-of-war

abstract:
  Intracellular transport is mediated by molecular motors that pull cargos
along cytoskeletal filaments. Many cargos move bidirectionally and are
transported by two teams of motors which move into opposite directions along
the filament. We have recently introduced a stochastic tug-of-war model for
this situation. This model describes the motion of the cargo as a Markov
process on a two-dimensional state space defined by the numbers of active plus
and active minus motors. In spite of its simplicity, this tug-of-war model
leads to a complex dependence of the cargo motility on the motor parameters. We
present new numerical results for the dependence on the number of involved
motors. In addition, we derive a simple and intuitive sharp maxima
approximation, from which one obtains the cargo motility state from only four
simple inequalities. This approach provides a fast and reliable method to
determine the cargo motility for a given experimental system.


title: Twisting Hermitian and hypercomplex geometries

abstract:
  A twist construction for manifolds with torus action is described
generalising certain T-duality examples and constructions in hypercomplex
geometry. It is applied to complex, SKT, hypercomplex and HKT manifolds to
construct compact simply-connected examples. In particular, we find
hypercomplex manifolds that admit no compatible HKT metric, and HKT manifolds
whose Obata connection has holonomy contained in $SL(n,\mathbb H)$.


title: Spectroscopy of the unbound: One-neutron knockout reaction of $^{14}$Be

abstract:
  Full Faddeev-type calculations are performed for one-neutron knockout
reaction of $^{14}$Be on proton target at 69 MeV/u incident energy. Inclusive
transverse momentum distributions for the outgoing ($^{12}$Be + n) system and
semi-inclusive cross sections are presented. A significant proton-core single
scattering contribution emerges where the valence neutron has non zero angular
momentum relative to the core. This indicates that distorted-wave impulse
approximation is inadequate and the complete multiple scattering series must be
taken into account for the considered reaction. The magnitude of the
semi-inclusive cross section at quasifree scattering conditions is a clear
signature of the angular momentum of the valence nucleon.


title: Symplectic implosion and non-reductive quotients

abstract:
  The symplectic implosion construction of Guillemin, Jeffrey and Sjamaar
associates to a Hamiltonian action of a compact group K on a symplectic
manifold X its 'imploded cross section'. When X is a complex projective variety
and K acts linearly on X, this construction is closely related to geometric
invariant theory (GIT) for the action on X of a maximal unipotent subgroup U of
the complexification G of K. The aim of this paper is to generalise symplectic
implosion to give a symplectic construction for GIT-like quotients by unipotent
radicals U of arbitrary parabolic subgroups P of the complex reductive group G
acting linearly on the projective variety X.


title: A note on dimension-5 operators in GUTs and their impact

abstract:
  Quantum gravity or string compactification can lead to effective dimension-5
operators in Grand Unified Theories which modify the gauge kinetic terms. We
exhaustively discuss the group-theoretic nature of such operators for the
popular SU(5), SO(10), and E(6) models. In particular, for SU(5) only a Higgs
in the 200 representation can help bring the couplings to unification below the
Planck scale and in consistency with proton decay limits while for a
supersymmetric version 24, 75, or 200 representations are all acceptable. The
results also have a direct application in non-universality of gaugino masses in
a class of supersymmetric models where identical group-theoretic features
obtain.


title:
Isospin diffusion in semi-peripheral $^{58}Ni$ + $^{197}Au$ collisions
  at intermediate energies (I): Experimental results

abstract:
  Isospin diffusion in semi-peripheral collisions is probed as a function of
the dissipated energy by studying two systems $^{58}Ni$ + $^{58}Ni$ and
$^{58}Ni$ + $^{197}Au$, over the incident energy range 52-74\AM. A close
examination of the multiplicities of light products in the forward part of
phase space clearly shows an influence of the isospin of the target on the
neutron richness of these products. A progressive isospin diffusion is observed
when collisions become more central, in connection with the interaction time.


title:
Prediction of Platinum Prices Using Dynamically Weighted Mixture of
  Experts

abstract:
  Neural networks are powerful tools for classification and regression in
static environments. This paper describes a technique for creating an ensemble
of neural networks that adapts dynamically to changing conditions. The model
separates the input space into four regions and each network is given a weight
in each region based on its performance on samples from that region. The
ensemble adapts dynamically by constantly adjusting these weights based on the
current performance of the networks. The data set used is a collection of
financial indicators with the goal of predicting the future platinum price. An
ensemble with no weightings does not improve on the naive estimate of no weekly
change; our weighting algorithm gives an average percentage error of 63% for
twenty weeks of prediction.


title:
Isospin diffusion in semi-peripheral $^{58}Ni$ + $^{197}Au$ collisions
  at intermediate energies (II): Dynamical simulations

abstract:
  We study isospin effects in semi-peripheral collisions above the Fermi energy
by considering the symmetric $^{58}Ni$ + $^{58}Ni$ and the asymmetric reactions
$^{58}Ni$ + $^{197}Au$ over the incident energy range 52-74 A MeV. A
microscopic transport model with two different parameterizations of the
symmetry energy term is used to investigate the isotopic content of
pre-equilibrium emission and the N/Z diffusion process. Simulations are also
compared to experimental data obtained with the INDRA array and bring
information on the degree of isospin equilibration observed in Ni + Au
collisions. A better overall agreement between data and simulations is obtained
when using a symmetry term which linearly increases with nuclear density.


title:
Evolutionary history of the UCP gene family: gene duplication and
  selection

abstract:
  BACKGROUND: The uncoupling protein (UCP) genes belong to the superfamily of
electron transport carriers of the mitochondrial inner membrane. Members of the
uncoupling protein family are involved in thermogenesis and determining the
functional evolution of UCP genes is important to understand the evolution of
thermo-regulation in vertebrates. RESULTS: Sequence similarity searches of
genome and scaffold data identified homologues of UCP in eutherians, teleosts
and the first squamates uncoupling proteins. Phylogenetic analysis was used to
characterize the family evolutionary history by identifying two duplications
early in vertebrate evolution and two losses in the avian lineage (excluding
duplications within a species, excluding the losses due to incompletely
sequenced taxa and excluding the losses and duplications inferred through
mismatch of species and gene trees). Estimates of synonymous and nonsynonymous
substitution rates (dN/dS) and more complex branch and site models suggest that
the duplication events were not associated with positive Darwinian selection
and that the UCP is constrained by strong purifying selection except for a
single site which has undergone positive Darwinian selection, demonstrating
that the UCP gene family must be highly conserved. CONCLUSION: We present a
phylogeny describing the evolutionary history of the UCP gene family and show
that the genes have evolved through duplications followed by purifying
selection except for a single site in the mitochondrial matrix between the 5th
and 6th alpha-helices which has undergone positive selection.


title: Detection of the second eclipsing high mass X-ray binary in M 33

abstract:
  Chandra data of the X-ray source [PMH2004] 47 were obtained in the ACIS
Survey of M 33 (ChASeM33) in 2006. During one of the observations, the source
varied from a high state to a low state and back, in two other observations it
varied from a low state to respectively intermediate states. These transitions
are interpreted as eclipse ingress and egresses of a compact object in a high
mass X-ray binary system. The phase of mid eclipse is given by HJD
2453997.476+-0.006, the eclipse half angle is 30.6+-1.2 degree. Adding
XMM-Newton observations of [PMH2004] 47 in 2001 we determine the binary period
to be 1.732479+-0.000027 d. This period is also consistent with ROSAT HRI
observations of the source in 1994. No short term periodicity compatible with a
rotation period of the compact object is detected. There are indications for a
long term variability similar to that detected for Her X-1. During the high
state the spectrum of the source is hard (power law spectrum with photon index
~0.85) with an unabsorbed luminosity of 2E37 erg/cm2/s (0.2-4.5 keV). We
identify as an optical counterpart a V ~ 21.0mag star with T_eff > 19000 K,
log(g) > 2.5. CFHT optical light curves for this star show an ellipsoidal
variation with the same period as the X-ray light curve. The optical light
curve together with the X-ray eclipse can be modeled by a compact object with a
mass consistent with a neutron star or a black hole in a high mass X-ray
binary. However, the hard power law X-ray spectrum favors a neutron star as the
compact object in this second eclipsing X-ray binary in M 33. Assuming a
neutron star with a canonical mass of 1.4 M_sun and the best fit companion
temperature of 33000 K, a system inclination i = 72 degree and a companion mass
of 10.9 M_sun are implied.


title: Partial symmetry, reflection monoids and Coxeter groups

abstract:
  This is the first of a series of papers in which we initiate and develop the
theory of reflection monoids, motivated by the theory of reflection groups. The
main results identify a number of important inverse semigroups as reflection
monoids, introduce new examples, and determine their orders.


title: Local density of states in disordered graphene

abstract:
  We study two lattice models, the honeycomb lattice (HCL) and a special square
lattice (SQL), both reducing to the Dirac equation in the continuum limit. In
the presence of disorder (gaussian potential disorder and random vector
potential), we investigate the behaviour of the density of states (DOS)
numerically and analytically. While an upper bound can be derived for the DOS
on the SQL at the Dirac point, which is also confirmed by numerical
calculations, no such upper limit exists for the HCL in the presence of random
vector potential. A careful investigation of the lowest eigenvalues indeed
indicate, that the DOS can possibly be divergent at the Dirac point on the HCL.
In spite of sharing a common continuum limit, these lattice models exhibit
different behaviour.


title: Thermodynamics of Anomaly-Driven Cosmology

abstract:
  The Friedmann equations of general relativity can be derived from the first
law of thermodynamics when the entropy of the apparent horizon of a spatially
isotropic universe is given by the Bekenstein-Hawking entropy. We point out
that if the entropy of the apparent horizon receives a logarithmic correction,
the first law of thermodynamics leads to a modified Friedmann equation which
corresponds precisely to the time-time component of the semi-classical Einstein
field equations sourced by the trace anomaly of ${\cal{N}}=4$ U(N)
super-Yang-Mills theory. This correspondence allows for a thermodynamic
description of the dynamics of the Randall-Sundrum braneworld scenario.


title:
Combined theory of two- and four- component complete orthonormal sets of
  spinor wave functions and Slater type spinor orbitals in position, momentum
  and four-dimensional spaces

abstract:
  By the use of complete orthonormal sets of nonrelativistic scalar orbitals
introduced by the author in previous papers the new complete orthonormal basis
sets for two- and four-component spinor wave functions, and Slater spinor
orbitals useful in the quantum-mechanical description of the spin- 1/2
particles by the quasirelativistic and Dirac's relativistic equations are
established in position, momentum and four-dimensional spaces. These function
sets are expressed through the corresponding nonrelativistic orbitals. The
analytical formulas for overlap integrals over four-component relativistic
Slater spinor orbitals with the same screening constants in position space are
also derived. The relations obtained in this study can be useful in the study
of different problems arising in the quasirelativistic and relativistic quantum
mechanics when the position, momentum and four dimensional spaces are employed.


title: Estimates for invariant metrics on $\Bbb C$-convex domains

abstract:
  Geometric lower and upper estimates are obtained for invariant metrics on
$\Bbb C$-convex domains containing no complex lines.


title: A freely relaxing polymer remembers how it was straightened

abstract:
  The relaxation of initially straight semiflexible polymers has been discussed
mainly with respect to the longest relaxation time. The biologically relevant
non-equilibrium dynamics on shorter times is comparatively poorly understood,
partly because "initially straight" can be realized in manifold ways. Combining
Brownian dynamics simulations and systematic theory, we demonstrate how
different experimental preparations give rise to specific short-time and
universal long-time dynamics. We also discuss boundary effects and the onset of
the stretch--coil transition.


title: |Vub| from Exclusive Semileptonic B--> rho Decays

abstract:
  We use Omnes representations of the form factors V, A_1 and A_2 for exclusive
semileptonic B--> rho decays, and apply them to combine experimental partial
branching fraction information with theoretical calculations of the three form
factors to extract |Vub|. We find a slightly lower result, |Vub|=(2.8 +- 0.2)x
10^{-3}, than the values extracted from exclusive semileptonic B-->pi decays
and using all other inputs in CKM fits. The disagreement is greater when we
compare to the result extracted from inclusive B -> X_u l nu decays.


title:
Growth and characterization of GaAs nanowires on carbon nanotubes
  composite films: toward flexible nanodevices

abstract:
  Poly(ethylene imine) functionalized carbon nanotube thin films, prepared
using the vacuum filtration method, were decorated with Au nanoparticles by in
situ reduction of HAuCl4 under mild conditions. These Au nanoparticles were
subsequently employed for the growth of GaAs nanowires (NWs) by the
vapor-liquid-solid process in a gas source molecular beam epitaxy system. The
process resulted in the dense growth of GaAs NWs across the entire surface of
the single-walled nanotube (SWNT) films. The NWs, which were orientated in a
variety of angles with respect to the SWNT films, ranged in diameter between 20
to 200 nm, with heights up to 2.5 um. Transmission electron microscopy analysis
of the NW-SWNT interface indicated that NW growth was initiated upon the
surface of the nanotube composite films. Photoluminescence characterization of
a single NW specimen showed high optical quality. Rectifying asymmetric
current-voltage behavior was observed from contacted NW ensembles and
attributed to the core-shell pn-junction within the NWs. Potential applications
of such novel hybrid architectures include flexible solar cells, displays, and
sensors.


title: The Chiral Condensate in a Finite Volume

abstract:
  Chiral perturbation theory at finite four-volume V (=L^3T) is reconsidered
with a view towards finding a computational scheme that can deal with any value
of M_\pi L, where M_\pi is a generic Nambu-Goldstone mass. The momentum zero
modes that cause the usual p-expansion to fail in the chiral limit are treated
separately, and partly integrated out to all orders. In this way the theory
remains infrared finite in the perturbative expansion, and the chiral limit can
be considered at finite volume. We illustrate the technique by computing the
quark condensate in a finite volume, smoothly connecting standard results in
the p-regime for larger masses with those of the epsilon-regime for smaller
masses. From the partially quenched theory we also obtain the spectral density
of the Dirac operator, a smooth function from the microscopic region to the
bulk region of the p-regime.


title:
Measurement of the short-range attractive force between Ge plates using
  a torsion balance

abstract:
  We have measured the short-range attractive force between crystalline Ge
plates, and found contributions from both the Casimir force and an electrical
force possibly generated by surface patch potentials. Using a model of surface
patch effects that generates an additional force due to a distance dependence
of the apparent contact potential, the electrical force was parameterized using
data at distances where the Casimir force is relatively small. Extrapolating
this model, to provide a correction to the measured force at distances less
than 5 $\mu$m, shows a residual force that is in agreement, within experimental
uncertainty, with five models that have been used to calculate the Casimir
force.


title:
PIERNIK mhd code - a multi-fluid, non-ideal extension of the
  relaxing-TVD scheme (II)

abstract:
  We present a new multi-fluid, grid MHD code PIERNIK, which is based on the
Relaxing TVD scheme (Jin and Xin, 1995). The original scheme (see Trac & Pen
(2003) and Pen et al. (2003)) has been extended by an addition of dynamically
independent, but interacting fluids: dust and a diffusive cosmic ray gas,
described within the fluid approximation, with an option to add other fluids in
an easy way. The code has been equipped with shearing-box boundary conditions,
and a selfgravity module, Ohmic resistivity module, as well as other facilities
which are useful in astrophysical fluid-dynamical simulations. The code is
parallelized by means of the MPI library. In this paper we introduce the
multifluid extension of Relaxing TVD scheme and present a test case of dust
migration in a two-fluid disk composed of gas and dust. We demonstrate that due
to the difference in azimuthal velocities of gas and dust and the drag force
acting on both components dust drifts towards maxima of gas pressure
distribution.


title: A measure of non-Gaussianity for quantum states

abstract:
  We propose a measure of non-Gaussianity for quantum states of a system of $n$
oscillator modes. Our measure is based on the quasi-probability $Q(\alpha),
\alpha\in{\cal C}^n$.
  Since any measure of non-Gaussianity is necessarily an attempt at making a
quantitative statement on the departure of the shape of the $Q$ function from
Gaussian, any good measure of non-Gaussianity should be invariant under
transformations which do not alter the shape of the $Q$ functions, namely
displacements, passage through passive linear systems, and uniform scaling of
all the phase space variables: $Q(\alpha)\to \lambda^{2n}Q(\lambda \alpha)$.
Our measure which meets this `shape criterion' is computed for a few families
of states, and the results are contrasted with existing measures of
non-Gaussianity. The shape criterion implies, in particular, that the
non-Gaussianity of the photon-added thermal states should be independent of
temperature.


title:
A modified Ehrenfest formalism for efficient large-scale ab initio
  molecular dynamics

abstract:
  We present in detail the recently derived ab-initio molecular dynamics (AIMD)
formalism [Phys. Rev. Lett. 101 096403 (2008)], which due to its numerical
properties, is ideal for simulating the dynamics of systems containing
thousands of atoms. A major drawback of traditional AIMD methods is the
necessity to enforce the orthogonalization of the wave-functions, which can
become the bottleneck for very large systems. Alternatively, one can handle the
electron-ion dynamics within the Ehrenfest scheme where no explicit
orthogonalization is necessary, however the time step is too small for
practical applications. Here we preserve the desirable properties of Ehrenfest
in a new scheme that allows for a considerable increase of the time step while
keeping the system close to the Born-Oppenheimer surface. We show that the
automatically enforced orthogonalization is of fundamental importance for large
systems because not only it improves the scaling of the approach with the
system size but it also allows for an additional very efficient parallelization
level. In this work we provide the formal details of the new method, describe
its implementation and present some applications to some test systems.
Comparisons with the widely used Car-Parrinello molecular dynamics method are
made, showing that the new approach is advantageous above a certain number of
atoms in the system. The method is not tied to a particular wave-function
representation, making it suitable for inclusion in any AIMD software package.


title: Resonance enhanced turbulent transport

abstract:
  The effect of oscillatory shear flows on turbulent transport of passive
scalar fields is studied by numerical computations based on the results
provided by E. Kim [\emph{Physics of Plasmas}, {\bf 13}, 022308, 2006].
Turbulent diffusion is found to depend crucially on the competition between
suppression due to shearing and enhancement due to resonances, depending on the
characteristic time and length scales of shear flow and turbulence.
Enhancements in transport occur for turbulence with finite memory time either
due to Doppler and parametric resonances. Scalings of turbulence amplitude and
transport are provided in different parameter spaces. The results suggest that
oscillatory shear flows are not only less efficient in regulating turbulence,
but also can enhance the value of turbulent diffusion, accelerating turbulent
transport.


title:
Formulation, Interpretation and Application of non-Commutative Quantum
  Mechanics

abstract:
  In analogy with conventional quantum mechanics, non-commutative quantum
mechanics is formulated as a quantum system on the Hilbert space of
Hilbert-Schmidt operators acting on non-commutative configuration space. It is
argued that the standard quantum mechanical interpretation based on Positive
Operator Valued Measures, provides a sufficient framework for the consistent
interpretation of this quantum system. The implications of this formalism for
rotational and time reversal symmetry are discussed. The formalism is applied
to the free particle and harmonic oscillator in two dimensions and the physical
signatures of non commutativity are identified.


title: Birefringence, CMB polarization and magnetized B-mode

abstract:
  Even in the absence of a sizable tensor contribution, a B-mode polarization
can be generated because of the competition between a pseudo-scalar background
and pre-decoupling magnetic fields. By investigating the dispersion relations
of a magnetoactive plasma supplemented by a pseudo-scalar interaction, the
total B-mode polarization is shown to depend not only upon the plasma and
Larmor frequencies but also on the pseudo-scalar rotation rate. If the
(angular) frequency channels of a given experiment are larger than the
pseudo-scalar rotation rate, the only possible source of (frequency dependent)
B-mode autocorrelations must be attributed to Faraday rotation. In the opposite
case the pseudo-scalar contribution dominates and the total rate becomes, in
practice, frequency-independent. The B-mode cross-correlations can be used,
under certain conditions, to break the degeneracy by disentangling the two
birefringent contributions.


title:
Compatibility conditions on local and global spectra for $n$-mode
  Gaussian states

abstract:
  Compatibility conditions between the (global) spectrum of an $n$-mode
Gaussian state and the spectra of the individual modes are presented, making
optimal use of beam splitter and (two-mode) squeezing transformations. An
unexpected bye-product of our elementary approach is the result that every
two-mode Gaussian state is uniquely determined, modulo local transformations,
by its global spectrum and local spectra -- a property shared not even by a
pair of qubits.


title: The High-Density Symmetry Energy in Heavy Ion Collisions

abstract:
  The nuclear symmetry energy as a function of density is rather poorly
constrained theoretically and experimentally both below saturation density, but
particularly at high density, where very few relevant experimental data exist.
We discuss observables which could yield information on this question, in
particular, proton-neutron flow differences, and the production of pions and
kaons in relativistic heavy ion collisions. For the meson production we
investigate particularly ratios of the corresponding isospin partners
$\pi^-/\pi^+$ and $K^0/K^+$, where we find that the kaons are an interesting
probe to the symmetry energy. In this case we also discuss the influnece of
various choices for the kaon potentials or in-medium effective masses.


title:
Self tuning phase separation in a model with competing interactions
  inspired by biological cell polarization

abstract:
  We present a theoretical study of a system with competing short-range
ferromagnetic attraction and a long-range anti-ferromagnetic repulsion, in the
presence of a uniform external magnetic field. The interplay between these
interactions, at sufficiently low temperature, leads to the self-tuning of the
magnetization to a value which triggers phase coexistence, even in the presence
of the external field. The investigation of this phenomenon is performed using
a Ginzburg-Landau functional in the limit of an infinite number of order
parameter components (large $N$ model). The scalar version of the model is
expected to describe the phase separation taking place on a cell surface when
this is immersed in a uniform concentration of chemical stimulant. A phase
diagram is obtained as function of the external field and the intensity of the
long-range repulsion. The time evolution of order parameter and of the
structure factor in a relaxation process are studied in different regions of
the phase diagram.


title:
Sparse polynomial space approach to dissipative quantum systems:
  Application to the sub-ohmic spin-boson model

abstract:
  We propose a general numerical approach to open quantum systems with a
coupling to bath degrees of freedom. The technique combines the methodology of
polynomial expansions of spectral functions with the sparse grid concept from
interpolation theory. Thereby we construct a Hilbert space of moderate
dimension to represent the bath degrees of freedom, which allows us to perform
highly accurate and efficient calculations of static, spectral and dynamic
quantities using standard exact diagonalization algorithms. The strength of the
approach is demonstrated for the phase transition, critical behaviour, and
dissipative spin dynamics in the spin boson model


title: An artificial dynamic heterogeneity in a glass-former below Tg

abstract:
  We report the first large scale molecular dynamics simulations of the effect
of the photoisomerization of probe molecules on the dynamics of a glassy
molecular material. We show that the photoisomerization of the probe molecules
induces the creation of an artificial dynamical heterogeneity inside the
matrix. We then study the modification of the dynamics and find, in agreement
with recent experiments, an important increase of the diffusion leading to
liquid like diffusion below the glass transition temperature. We find that the
photoisomerization process controls the heterogeneity and the non-Gaussian
parameter of the material, leading to extremely rapid variations of these
quantities.


title: Consistent gravitational anomalies for chiral bosons

abstract:
  Exact consistent gravitational anomalies for chiral bosons in two dimensions
are treated both with the Schwinger-DeWitt regularization and independently
through a cohomological procedure. The diffeomorphism transformations are
described by a single ghost which allows to climb the cohomological chain in a
unique way.


title:
A universal inequality for axisymmetric and stationary black holes with
  surrounding matter in the Einstein-Maxwell theory

abstract:
  We prove that in Einstein-Maxwell theory the inequality $(8\pi J)^2+(4\pi
Q^2)^2 < A^2$ holds for any sub-extremal axisymmetric and stationary black hole
with arbitrary surrounding matter. Here $J, Q$, and $A$ are angular momentum,
electric charge, and horizon area of the black hole, respectively.


title:
The host galaxies of Compact Steep Spectrum and Gigahertz-Peaked
  Spectrum radio sources

abstract:
  I will review some of the developments in studies of the host galaxy
properties of Compact Steep Spectrum (CSS) and GigaHertz-Peaked Spectrum (GPS)
radio sources. In contrast to previous reviews structured around observational
technique, I will discuss the host galaxy properties in terms of morphology,
stellar content and warm gas properties and discuss how compact, young
radio-loud AGN are key objects for understanding galaxy evolution.


title: Testing the blast wave model with Swift GRBs

abstract:
  The complex structure of the light curves of Swift GRBs has made the
identification of breaks, and the interpretation of the blast wave caused by
the burst, more difficult than in the pre-Swift era. We aim to identify breaks,
which are possibly hidden, and to constrain the blast wave parameters; electron
energy distribution, p, density profile of the circumburst medium, k, and the
continued energy injection index, q. We do so by comparing the observed
multi-wavelength light curves and X-ray spectra of our sample to the
predictions of the blast wave model.
  We can successfully interpret all of the bursts in our sample of 10, except
two, within this framework and we can estimate, with confidence, the electron
energy distribution index for 6 of the sample. Furthermore we identify jet
breaks in a number of the bursts. A statistical analysis of the distribution of
p reveals that, even in the most conservative case of least scatter, the values
are not consistent with a single, universal value. The values of k suggest that
the circumburst density profiles are not drawn from only one of the constant
density or wind-like media populations.


title: Overdensities of galaxies at z ~ 3.7 in CDF-S

abstract:
  We report the discovery of possible overdensities of galaxies at z ~ 3.7 in
the Chandra Deep Field South (CDF-S). These overdensities are identified from
the photometric redshift selected sample, and the BVz-selected sample. One
over-density is identified in the proximity of 2 AGNs and LBGs at z=3.66 and
z=3.70 at 7-sigma significance level. The other over-density is less
significant. It is identified around six z_{spec} ~ 3.6 galaxies at 3-sigma
significance level. The line of sight velocity dispersions of these
overdensities are found to be sigma_{v} ~ 500-800 km/sec, comparable to the
velocity dispersions of clusters of galaxies today. Through the spectral energy
distribution (SED) fitting, we find ~15 massive galaxies with M > 10^{11}M_sun
around the z ~ 3.7 overdensity. The mass of the z ~ 3.7 overdensity is found to
be a few times 10^{14}M_sun. Our result suggests that high redshift over-dense
regions can be found in a supposedly blank field, and that the emergence of
massive structures can be traced back to redshift as high as z ~ 3.7.


title:
An Accurate Determination of the Optical Periodic Modulation in the
  X-Ray Binary SAX J1808.4-3658

abstract:
  We report on optical imaging of the X-ray binary SAX J1808.4-3658 with the
8-m Gemini South Telescope. The binary, containing an accretion-powered
millisecond pulsar, appears to have a large periodic modulation in its
quiescent optical emission. In order to clarify the origin of this modulation,
we obtained three time-resolved $r'$-band light curves (LCs) of the source in
five days. The LCs can be described by a sinusoid, and the long time-span
between them allows us to determine optical period P=7251.9 s and phase 0.671
at MJD 54599.0 (TDB; phase 0.0 corresponds to the ascending node of the pulsar
orbit), with uncertainties of 2.8 s and 0.008 (90 % confidence), respectively.
This periodicity is highly consistent with the X-ray orbital ephemeris. By
considering this consistency and the sinusoidal shape of the LCs, we rule out
the possibility of the modulation arising from the accretion disk. Our study
supports the previous suggestion that the X-ray pulsar becomes rotationally
powered in quiescence, with its energy output irradiating the companion star,
causing the optical modulation. While it has also been suggested that the
accretion disk would be evaporated by the pulsar, we argue that the disk exists
and gives rise to the persistent optical emission. The existence of the disk
can be verified by long-term, multi-wavelength optical monitoring of the source
in quiescence, as an increasing flux and spectral changes from the source would
be expected based on the standard disk instability model.


title: Optics in a field of gravity

abstract:
  An observer at rest in a uniformly accelerated reference frame experiences a
parallel gravitational field, where the rays of light are formed as circular
arcs instead of being straight lines. We deduce how a sphere at rest in the
Rindler frame, and a freely falling sphere, will appear to an observer at rest
in the frame.


title: Tutte polynomial and G-parking functions

abstract:
  Let $G$ be a connected graph with vertex set $\{0,1,2,...,n\}$. We allow $G$
to have multiple edges and loops. In this paper, we give a characterization of
external activity by some parameters of $G$-parking functions. In particular,
we give the definition of the bridge vertex of a $G$-parking function and
obtain an expression of the Tutte polynomial $T_G(x,y)$ of $G$ in terms of
$G$-parking functions. We find the Tutte polynomial enumerates the $G$-parking
function by the number of the bridge vertices.


title: Sparse recovery under matrix uncertainty

abstract:
  We consider the model {eqnarray*}y=X\theta^*+\xi, Z=X+\Xi,{eqnarray*} where
the random vector $y\in\mathbb{R}^n$ and the random $n\times p$ matrix $Z$ are
observed, the $n\times p$ matrix $X$ is unknown, $\Xi$ is an $n\times p$ random
noise matrix, $\xi\in\mathbb{R}^n$ is a noise independent of $\Xi$, and
$\theta^*$ is a vector of unknown parameters to be estimated. The matrix
uncertainty is in the fact that $X$ is observed with additive error. For
dimensions $p$ that can be much larger than the sample size $n$, we consider
the estimation of sparse vectors $\theta^*$. Under matrix uncertainty, the
Lasso and Dantzig selector turn out to be extremely unstable in recovering the
sparsity pattern (i.e., of the set of nonzero components of $\theta^*$), even
if the noise level is very small. We suggest new estimators called matrix
uncertainty selectors (or, shortly, the MU-selectors) which are close to
$\theta^*$ in different norms and in the prediction risk if the restricted
eigenvalue assumption on $X$ is satisfied. We also show that under somewhat
stronger assumptions, these estimators recover correctly the sparsity pattern.


title: The informational physics indeed can help to understand Nature?

abstract:
  In our previous articles ("The Information and the Matter", v1, v5; more
systematically the informational conception is presented in arXiv paper "The
Information as Absolute", 2010) it was rigorously shown that the Matter is some
informational system (structure), which is an [practically] infinitesimal
sub-sets of the utmost infinite and fundamental Set "Information". Here some
physical consequences from this conception are considered.


title: Refinements of Lattice paths with flaws

abstract:
  The classical Chung-Feller theorem [2] tells us that the number of Dyck paths
of length $n$ with $m$ flaws is the $n$-th Catalan number and independent on
$m$. In this paper, we consider the refinements of Dyck paths with flaws by
four parameters, namely peak, valley, double descent and double ascent. Let
${p}_{n,m,k}$ be the number of all the Dyck paths of semi-length $n$ with $m$
flaws and $k$ peaks. First, we derive the reciprocity theorem for the
polynomial $P_{n,m}(x)=\sum\limits_{k=1}^np_{n,m,k}x^k$. Then we find the
Chung-Feller properties for the sum of $p_{n,m,k}$ and $p_{n,m,n-k}$. Finally,
we provide a Chung-Feller type theorem for Dyck paths of length $n$ with $k$
double ascents: the number of all the Dyck paths of semi-length $n$ with $m$
flaws and $k$ double ascents is equal to the number of all the Dyck paths that
have semi-length $n$, $k$ double ascents and never pass below the x-axis, which
is counted by the Narayana number. Let ${v}_{n,m,k}$ (resp. $d_{n,m,k}$) be the
number of all the Dyck paths of semi-length $n$ with $m$ flaws and $k$ valleys
(resp. double descents). Some similar results are derived.


title:
High density quark matter in the NJL model with dimensional vs. cut-off
  regularization

abstract:
  We investigate color superconducting phase at high density in the extended
Nambu--Jona-Lasinio model for the two flavor quarks. Because of the
non-renormalizability of the model, physical observables may depend on the
regularization procedure, that is why we apply two types of regularization, the
cut-off and the dimensional one to evaluate the phase structure, the equation
of state and the relationship between the mass and the radius of a dense star.
To obtain the phase structure we evaluate the minimum of the effective
potential at finite temperature and chemical potential. The stress tensor is
calculated to derive the equation of state. Solving the
Tolman-Oppenheimer-Volkoff equation, we show the relationship between the mass
and the radius of a dense star. The dependence on the regularization is found
not to be small for these phenomena in the color superconducting phase.


title: Dynamics of glass phases in the two-dimensional gauge glass model

abstract:
  Large-scale simulations have been performed on the current-driven
two-dimensional XY gauge glass model with resistively-shunted-junction
dynamics. It is observed that the linear resistivity at low temperatures tends
to zero, providing strong evidence of glass transition at finite temperature.
Dynamic scaling analysis demonstrates that perfect collapses of current-voltage
data can be achieved with the glass transition temperature $T_{g}=0.22$, the
correlation length critical exponent $\nu =1.8$, and the dynamic critical
exponent $ z=2.0$. A genuine continuous depinning transition is found at zero
temperature. For creeping at low temperatures, critical exponents are evaluated
and a non-Arrhenius creep motion is observed in the glass phase.


title: Lifetime statistics in chaotic dielectric microresonators

abstract:
  We discuss the statistical properties of lifetimes of electromagnetic
eigenmodes in dielectric microresonators with fully chaotic ray dynamics. Using
the example of a resonator of stadium geometry, we find that a recently
proposed random-matrix model very well describes the lifetime statistics of
long-lived resonances, provided that two effective parameters are appropriately
renormalized. This renormalization is linked to the formation of anomalously
short-lived resonances, a mechanism also known from the fractal Weyl law and
the resonance trapping phenomenon.


title:
Application of the Trend Filtering Algorithm in the search for
  multiperiodic signals

abstract:
  During the past few years the Trend Filtering Algorithm (TFA) has become an
important utility in filtering out time-dependent systematic effects in
photometric databases for extrasolar planetary transit search. Here we present
the extension of the method to multiperiodic signals and show the high
efficiency of the signal detection over the direct frequency analysis on the
original database derived by today's standard methods (e.g., aperture
photometry). We also consider the (iterative) signal reconstruction that
involves the proper extraction of the systematics. The method is demonstrated
on the database of fields observed by the HATNet project. A preliminary
variability statistics suggests incidence rates between 4 and 10% with many
(sub)mmag amplitude variables.


abstract:
  The Husain-Kuchar theory is a four-dimensional background-independent model
that has long been viewed as a useful model for addressing several conceptual
and technical problems appearing in the quantization of general relativity
mainly in the loop quantum gravity approach. The model was defined at
Lagrangian level in terms of a su(2)-valued connection one-form $A$ coupled
through its curvature to a su(2)-valued one-form field $e$. We address here the
problem of writing a Lagrangian formulation for the Husain-Kuchar model as a
constrained BF theory motivated by the fact that spin foam models for quantum
gravity are related to action principles of the BF type. The Lagrangian action
principle for the Husain-Kuchar model reported here differs from a previous one
found by Barbero et al in that this description involves a single constrained
BF theory rather than two interacting BF theories. It is, essentially, the
Plebanski action with the condition on the trace of the Lagrange multipliers
removed. Moreover, it can be stated that the relationship between our BF-like
action and the original one for the Husain-Kuchar model is the same
relationship that exists between the Plebanski action and the self-dual
Palatini action for complex general relativity, first because the solution to
the constraint on the two-forms $\Sigma^i$ coming from the BF-like action leads
to the Husain-Kuchar action, and second because the Hamiltonian analysis of the
Husain-Kuchar model is straightforward starting from the BF-like action
principle.


title: A Unification of Two Refinements of Euler's Partition Theorem

abstract:
  We obtain a unification of two refinements of Euler's partition theorem
respectively due to Bessenrodt and Glaisher. A specialization of Bessenrodt's
insertion algorithm for a generalization of the Andrews-Olsson partition
identity is used in our combinatorial construction.


title:
Competition of magnetism and superconductivity in underdoped
  (Ba1-xKx)Fe2As2

abstract:
  Polycrystalline samples of underdoped (Ba1-xKx)Fe2As2 (x<=0.4) were
synthesized and studied by x-ray powder diffraction, magnetic susceptibility,
specific heat and 57Fe-Moessbauer-spectroscopy. The structural phase transition
from tetragonal to orthorhombic lattice symmetry shifts towards lower
temperatures, becomes less pronounced at x = 0.1-0.2 and is no longer present
at x = 0.3. Bulk superconductivity is observed in all samples except
(Ba0.9K0.1)Fe2As2 by resistivity and magnetic susceptibility measurements.
Specific heat data show a broad SDW phase transition in (Ba0.9K0.1)Fe2As2,
which is hardly discernible in (Ba0.8K0.2)Fe2As2. No SDW anomaly is found in
the specific heat of optimally doped (Ba0.6K0.4)Fe2As2, where C changes by 0.1
J/K at Tc = 37.3 K. 57Fe-Moessbauer-spectra show full magnetic hyperfine field
splitting, indicative of antiferromagnetic ordering at 4.2 K in samples with x
= 0-0.2, but zero magnetic hyperfine field in samples with x = 0.3. The spectra
of (Ba0.9K0.1)Fe2As2 and (Ba0.8K0.2)Fe2As2 in the phase transition regions are
temperature-dependent superpositions of magnetic and non-magnetic components,
caused by inhomogeneous potassium distribution. Our results suggest the
co-existence of AF magnetic ordering and superconductivity without mesoscopic
phase separation in the underdoped region and show unambiguously homogeneous
superconducting phases close to optimal doping. This is in contrast to recently
reported results about single crystal (Ba1-xKx)Fe2As2.


title: Molecular Superbubbles and Outflows from Starburst Galaxy NGC 2146

abstract:
  We present results from a deep (1 sigma = 5.7 mJy beam^{-1} per 20.8 km
s^{-1} velocity channel) ^{12}CO(1-0) interferometric observation of the
central 60" region of the nearby edge-on starburst galaxy NGC 2146 observed
with the Nobeyama Millimeter Array (NMA). Two diffuse expanding molecular
superbubbles and one molecular outflow are successfully detected. One molecular
superbubble, with a size of ~1 kpc and an expansion velocity of ~50 km s^{-1},
is located below the galactic disk; a second molecular superbubble, this time
with a size of ~700 pc and an expansion velocity of ~35 km s^{-1}, is also seen
in the position-velocity diagram; the molecular outflow is located above the
galactic disk with an extent ~2 kpc, expanding with a velocity of up to ~200 km
s^{-1}. The molecular outflow has an arc-like structure, and is located at the
front edge of the soft X-ray outflow. In addition, the kinetic energy (~3E55
erg) and the pressure (~1 E-12 \pm 1 dyne cm ^{-2}) of the molecular outflow is
comparable to or smaller than that of the hot thermal plasma, suggesting that
the hot plasma pushes the molecular gas out from the galactic disk. Inside the
~1 kpc size molecular superbubble, diffuse soft X-ray emission seems to exist.
But since the superbubble lies behind the inclined galactic disk, it is largely
absorbed by the molecular gas.


title: Precise Measurement of pi+ -> e+ nu Branching Ratio

abstract:
  The PEN Collaboration is conducting a new measurement of the pi+ -> e+ nu
branching ratio at the Paul Scherrer Institute, with the goal uncertainty of
delta B/B(pie2)=5E-4 or lower. At present, the combined accuracy of all
published pie2 decay measurements lags behind the theoretical calculation by a
factor of 40. In this contribution we report on the PEN detector configuration
and its performance during two development runs done in 2007 and 2008.


title: Adatom diffusion on vicinal surfaces with permeable steps

abstract:
  We study the behavior of single atoms on an infinite vicinal surface assuming
certain degree of step permeability. Assuming complete lack of re-evaporation
an ruling out nucleation the atoms will inevitably join kink sites at the steps
but can do many attempts before that. Increasing the probability of step
permeability or the kink spacing lead to increase of the number of steps
crossed before incorporation of the atoms into kink sites. The asymmetry of the
attachment-detachment kinetics (Ehrlich-Schwoebel effect) suppresses the step
permeability and completely eliminates it in the extreme case of infinite
Ehrlich-Schwoebel barrier. The average number of permeability events per atom
scales with the average kink spacing. A negligibly small drift of the adatoms
in a direction perpendicular to the steps leads to a significant asymmetry of
the distribution of the permeability events the atoms thus visiting more
distant steps in the direction of the drift.


title: Color superconductivity and dense quark matter

abstract:
  The properties of cold and dense quark matter have been the subject of
extensive investigation, especially in the last decade. Unfortunately, we still
lack of a complete understanding of the properties of matter in these
conditions. One possibility is that quark matter is in a color superconducting
phase which is characterized by the formation of a diquark condensate. We
review some of the basic concepts of color superconductivity and some of the
aspects of this phase of matter which are relevant for compact stars. Since
quarks have color, flavor as well as spin degrees of freedom many different
color superconducting phases can be realized. At asymptotic densities QCD
predicts that the color flavor locked phase is favored. At lower densities
where the QCD coupling constant is large, perturbative methods cannot be
applied and one has to rely on some effective model, eventually trying to
constrain such a model with experimental observations. The picture is
complicated by the requirement that matter in the interior of compact stars is
in weak equilibrium and neutral. These conditions and the (possible) large
value of the strange quark mass conspire to separate the Fermi momenta of
quarks with different flavors, rendering homogenous superconducting phases
unstable. One of the aims of this presentation is to introduce non-experts in
the field to some of the basic ideas of color superconductivity and to some of
its open problems.


title: S-waves and the Measurement of CP Violating Phases in Bs Decays

abstract:
  Heavy, as yet undiscovered particles, can affect measurements of CP violation
in the B system. Measuring CP violation in the Bs system provides an excellent
place to observe such effects since Standard Model sources are predicted to
produce very small effects. The angle -2beta_s, the "phase of Bs-\bar{B}s
mixing," thought to be best measured in Bs -> J/psi\phi decays is of order
-0.04, while the CP violating asymmetry in Bs -> \phi\phi is predicted to be
zero, due to the cancellation of the mixing phase with the decay phase. Recent
measurements of \beta_s in J/psi\phi, while not definitive, are much larger
than the Standard Model predictions. Measurements in the B^o and Ds+ systems of
analogous modes point toward a 5-10% contamination of S-wave K+K- under the
\phi peak. This S-wave was not taken into account in these recent analyses.
Furthermore this S-wave can also materialize as a f0(980) meson that decays to
\pi+\pi-, making the final state J/psi f0 useful for measuring \beta_s with the
added advantage of not requiring an angular analysis. Rate estimates, while not
precise, predict four to five times fewer such events than those in the
J/psi\phi mode. The error on \beta_s, however, may be similar. We also remark
on S-wave problems with the Bs -> \phi\phi mode, and possible systematic checks
using Bs -> \phi f0.


title: Some subtleties of Riemannian geometry

abstract:
  It is shown, that the conventional presentation of the Maxwell equations for
the electromagnetic field in the Riemannian space-time appears to be
problematic. The reason of hesitations is the fact, that a solution of the
Maxwell equations in the space-time of Minkowski do not turn into solution of
the Maxwell equations in the Riemannian space-time after replacement of
Minkowskian world function $\sigma_{M}$ by the world function $\sigma_R$ of the
Riemannian space-time in the solution.


title:
Status and overview of development of the Silicon Pixel Detector for the
  PHENIX experiment at the BNL RHIC

abstract:
  We have developed a silicon pixel detector to enhance the physics
capabilities of the PHENIX experiment. This detector, consisting of two layers
of sensors, will be installed around the beam pipe at the collision point and
covers a pseudo-rapidity of | \eta | < 1.2 and an azimuth angle of | \phi | ~
2{\pi}. The detector uses 200 um thick silicon sensors and readout chips
developed for the ALICE experiment. In order to meet the PHENIX DAQ readout
requirements, it is necessary to read out 4 readout chips in parallel. The
physics goals of PHENIX require that radiation thickness of the detector be
minimized. To meet these criteria, the detector has been designed and
developed. In this paper, we report the current status of the development,
especially the development of the low-mass readout bus and the front-end
readout electronics.


title: The GL(1|1)-symplectic fermion correspondence

abstract:
  In this note we prove a correspondence between the Wess-Zumino-Novikov-Witten
model of the Lie supergroup GL(1|1) and a free model consisting of two scalars
and a pair of symplectic fermions. This model was discussed earlier by LeClair.
Vertex operators for the symplectic fermions include twist fields, and
correlation functions of GL(1|1) agree with the known results for the scalars
and symplectic fermions. We perform a detailed study of boundary states for
symplectic fermions and apply them to branes in GL(1|1). This allows us to
compute new amplitudes of strings stretching between branes of different types
and confirming Cardy's condition.


title: Angular Momentum Loss and Stellar spin-down in Magnetic Massive Stars

abstract:
  We examine the angular momentum loss and associated rotational spin-down for
magnetic hot stars with a line-driven stellar wind and a rotation-aligned
dipole magnetic field. Our analysis here is based on our previous 2-D numerical
MHD simulation study that examines the interplay among wind, field, and
rotation as a function of two dimensionless parameters, W(=Vrot/Vorb) and 'wind
magnetic confinement', $\eta_\ast$ defined below. We compare and contrast the
2-D, time variable angular momentum loss of this dipole model of a hot-star
wind with the classical 1-D steady-state analysis by Weber and Davis (WD), who
used an idealized monopole field to model the angular momentum loss in the
solar wind. Despite the differences, we find that the total angular momentum
loss averaged over both solid angle and time follows closely the general WD
scaling $\dot {J} \sim \dot {M} \Omega R_A^2$. The key distinction is that for
a dipole field Alfv\`en radius $R_A$ is significantly smaller than for the
monopole field WD used in their analyses. This leads to a slower stellar
spin-down for the dipole field with typical spin-down times of order 1 Myr for
several known magnetic massive stars.


title:
Rejoinder to the Response arXiv:0812.2330 to 'Comment on a recent
  conjectured solution of the three-dimensional Ising model'

abstract:
  We comment on Z. D. Zhang's Response [arXiv:0812.2330] to our recent Comment
[arXiv:0811.3876] addressing the conjectured solution of the three-dimensional
Ising model reported in [arXiv:0705.1045].


title: Transverse Momentum Broadening in Semi-inclusive DIS on Nuclei

abstract:
  Using a three stage model of hadron formation we calculate the change of the
transverse momentum distribution of hadrons produced in semi-inclusive deep
inelastic scattering (SIDIS) on nuclei. In the first stage after its
interaction with the virtual photon, the struck quark propagates quasi free in
the nuclear environment undergoing multiple collisions with nucleons. During
this stage it can acquire transverse momentum. In the second stage a prehadron
is formed which has a very small elastic cross section with the nucleons. In
the third stage the prehadron turns into a hadron. For HERMES energies,
prehadron elastic scatterings contribute little to $p_\perp$-broadening. The
acquired extra $\Delta p_\perp^2$ of hadrons can therefore be deduced entirely
from the first stage of quasi free quark propagation with quark-nucleon
collisions. We use this model to describe $\pi$-production on Ne, Kr, Xe and
compare with the most recent HERMES preliminary data.


title: An empirical central limit theorem in L^1 for stationary sequences

abstract:
  In this paper, we derive asymptotic results for L^1-Wasserstein distance
between the distribution function and the corresponding empirical distribution
function of a stationary sequence. Next, we give some applications to dynamical
systems and causal linear processes. To prove our main result, we give a
Central Limit Theorem for ergodic stationary sequences of random variables with
values in L^1. The conditions obtained are expressed in terms of
projective-type conditions. The main tools are martingale approximations.


title:
Comprehensive Characterization of InGaAs/InP Avalanche Photodiodes at
  1550 nm with an Active Quenching ASIC

abstract:
  We present an active quenching application specific integrated circuit
(ASIC), for use in conjunction with InGaAs/InP avalanche photodiodes (APDs),
for 1550 nm single-photon detection. To evaluate its performance, we first
compare its operation with that of standard quenching electronics. We then test
4 InGaAs/InP APDs using the ASIC, operating both in the free-running and gated
modes, to study more general behavior. We investigate not only the standard
parameters under different working conditions but also parameters such as
charge persistence and quenching time. We also use the multiple trapping model
to account for the afterpulsing behavior in the gated mode, and further propose
a model to take account of the afterpulsing effects in the free-running mode.
Our results clearly indicate that the performance of APDs with an on-chip
quenching circuit significantly surpasses the conventional quenching
electronics, and makes them suitable for practical applications, e.g., quantum
cryptography.


title: On a congruence only holding for primes II

abstract:
  We present a primality criterium based on congruences for cyclotomic
polynomials, and point out a way to generalize our result in order to obtain a
family of similar criteria. No practical use is aimed however.


title: Rings, spirals and manifolds

abstract:
  Two-armed, grand design spirals and inner and outer rings in barred galaxies
can be due to orbits guided by the manifolds emanating from the vicinity of the
L1 and L2 Lagrangian points, located at the ends of the bar. We first summarise
the necessary theoretical background and in particular we describe the dynamics
around the unstable equilibrium points in barred galaxy models, and the
corresponding homoclinic and heteroclinic orbits. We then discuss two specific
morphologies and the circulation of material within the corresponding
manifolds. We also discuss the case where mass concentrations at the end of the
bar can stabilise the L1 and L2 and the relevance of this work to the gas
concentrations in spirals and rings.


title: Slow-Roll Inflation in the Presence of a Dark Energy Coupling

abstract:
  In models of coupled dark energy, in which a dark energy scalar field couples
to other matter components, it is natural to expect a coupling to the inflaton
as well. We explore the consequences of such a coupling in the context of
single field slow-roll inflation. Assuming an exponential potential for the
quintessence field we show that the coupling to the inflaton causes the
quintessence field to be attracted towards the minimum of the effective
potential. If the coupling is large enough, the field is heavy and is located
at the minimum. We show how this affects the expansion rate and the slow-roll
of the inflaton field, and therefore the primordial perturbations generated
during inflation. We further show that the coupling has an important impact on
the processes of reheating and preheating.


title:
A Central Partition of Molecular Conformational Space. V. The Hypergraph
  of 3D Partition Sequences

abstract:
  In a previous work a procedure was decribed for dividing the $3 \times
N$-dimensional conformational space of a molecular system into a number of
discrete cells, this partition allowed the building of a combinatorial
structure from data sampled in molecular dynamics trajectories: the graph of
cells or G, encoding the set of cells in conformational space that are visited
by the system in its thermal wandering. The information in G however, is
encoded in a great number of fragments that must be aggregated. We describe
here the algorithmic procedures 1) for aggregating the information from G into
an hypergraph allowing to enumerate the relevant cells from conformational
space, and 2) for puttting the data in a very compact format.


title: Formulas for the Connes-Moscovici Hopf algebra

abstract:
  We give explicit formulas for the coproduct and the antipode in the
Connes-Moscovici Hopf algebra $\mathcal{H}_{\tmop{CM}}$. To do so, we first
restrict ourselves to a sub-Hopf algebra $\mathcal{H}^1_{\tmop{CM}}$ containing
the nontrivial elements, namely those for which the coproduct and the antipode
are nontrivial. There are two ways to obtain explicit formulas. On one hand,
the algebra $\mathcal{H}^1_{\tmop{CM}}$ is isomorphic to the Fa\`a di Bruno
Hopf algebra of coordinates on the group of identity-tangent diffeomorphism and
computations become easy using substitution automorphisms rather than
diffeomorphisms. On the other hand, the algebra $\mathcal{H}^1_{\tmop{CM}}$ is
isomorphic to a sub-Hopf algebra of the classical shuffle Hopf algebra which
appears naturally in resummation theory, in the framework of formal and
analytic conjugacy of vector fields. Using the very simple structure of the
shuffle Hopf algebra, we derive once again explicit formulas for the coproduct
and the antipode in $\mathcal{H}^1_{\tmop{CM}}$.


title:
Reconstructing Cosmological Matter Perturbations using Standard Candles
  and Rulers

abstract:
  For a large class of dark energy (DE) models, for which the effective
gravitational constant is a constant and there is no direct exchange of energy
between DE and dark matter (DM), knowledge of the expansion history suffices to
reconstruct the growth factor of linearized density perturbations in the
non-relativistic matter component on scales much smaller than the Hubble
distance. In this paper we develop a non-parametric method for extracting
information about the perturbative growth factor from data pertaining to the
luminosity or angular size distances. A comparison of the reconstructed density
contrast with observations of large scale structure and gravitational lensing
can help distinguish DE models such as the cosmological constant and
quintessence from models based on modified gravity theories as well as models
in which DE and DM are either unified, or interact directly. We show that for
current SNe data, the linear growth factor at z = 0.3 can be constrained to 5%,
and the linear growth rate to 6%. With future SNe data, such as expected from
the JDEM mission, we may be able to constrain the growth factor to 2-3% and the
growth rate to 3-4% at z = 0.3 with this unbiased, model-independent
reconstruction method. For future BAO data which would deliver measurements of
both the angular diameter distance and Hubble parameter, it should be possible
to constrain the growth factor at z = 2.5 to 9%. These constraints grow tighter
with the errors on the datasets. With a large quantity of data expected in the
next few years, this method can emerge as a competitive tool for distinguishing
between different models of dark energy.


title:
The Frequency of Warm Debris Disks and Transition Disks in a Complete
  Sample of Intermediate-Mass GLIMPSE Stars: Placing Constraints on Disk
  Lifetimes

abstract:
  The incidence of dusty debris disks around low- and intermediate-mass stars
has been investigated numerous times in order to understand the early stages of
planet formation. Most notably, the IRAS mission observed the entire sky at
mid- and far-IR wavelengths, identifying the first debris disk systems, but was
unable to detect a statistically significant sample of warm debris disks due to
its limited sensitivity at 12 microns. Using Tycho-2 Spectral Catalog stars
previously shown to exhibit 8 micron mid-infrared circumstellar excesses
confirmed at 24 microns in the Spitzer GLIMPSE survey, we investigate the
frequency of mid-IR excesses among intermediate-mass (2--4 solar mass) stars in
a complete volume-limited sample. Our study of 338 stars is four times larger
than a complete sample of 12 micron sources from the IRAS Point Source Catalog.
We find that 0.3+-0.3% of intermediate-mass stars exhibit a signature of a
possible terrestrial-temperature debris disks at wavelengths of 8 microns and
greater. We also find that 1.2+-0.6% of intermediate-mass stars exhibit
evidence for circumstellar disks undergoing inner disk clearing, i.e.,
candidate transition disk systems. Using stellar lifetimes and the frequency of
transition and primordial disks within a given spectral type, we find that
pre-main-sequence disks around intermediate-mass stars dissipate in 5+-2 Myr,
consistent with other studies.


title: Indefinite oscillators and black-hole evaporation

abstract:
  We discuss the dynamics of two harmonic oscillators of which one has a
negative kinetic term. This model mimics the Hamiltonian in quantum
geometrodynamics, which possesses an indefinite kinetic term. We solve for the
time evolution in both the uncoupled and coupled case. We use this setting as a
toy model for studying some possible aspects of the final stage of black-hole
evaporation. We assume that one oscillator mimics the black hole, while the
other mimics Hawking radiation. In the uncoupled case, the negative term leads
to a squeezing of the quantum state, while in the coupled case, which includes
back reaction, we get a strong entangled state between the mimicked black hole
and the radiation. We discuss the meaning of this state. We end by analyzing
the limits of this model and its relation to more fundamental approaches.


title: Remarques sur une conjecture de Lang

abstract:
  The aim of this paper is to study a conjecture predicting a lower bound on
the canonical height on abelian varieties, formulated by S. Lang and
generalized by J. H. Silverman. We give here an asymptotic result on the height
of Heegner points on the modular jacobian $J_{0}(N)$, and we derive non-trivial
remarks about the conjecture.


title:
Collisional effects in the formation of cold guided beams of polar
  molecules

abstract:
  High fluxes of cold polar molecules are efficiently produced by electric
guiding and velocity filtering. Here, we investigate different aspects of the
beam formation. Variations of the source parameters such as density and
temperature result in characteristic changes in the guided beam. These are
observed in the velocity distribution of the guided molecules as well as in the
dependence of the signal of guided molecules on the trapping electric field. A
model taking into account velocity-dependent collisional losses of cold
molecules in the region close to the nozzle accurately reproduces this
behavior. This clarifies an open question on the parameter dependence of the
detected signal and gives a more detailed understanding of the velocity
filtering and guiding process.


title: The Violation Heap: A Relaxed Fibonacci-Like Heap

abstract:
  We give a priority queue that achieves the same amortized bounds as Fibonacci
heaps. Namely, find-min requires O(1) worst-case time, insert, meld and
decrease-key require O(1) amortized time, and delete-min requires $O(\log n)$
amortized time. Our structure is simple and promises an efficient practical
behavior when compared to other known Fibonacci-like heaps. The main idea
behind our construction is to propagate rank updates instead of performing
cascaded cuts following a decrease-key operation, allowing for a relaxed
structure.


title: Spectral tripartitioning of networks

abstract:
  We formulate a spectral graph-partitioning algorithm that uses the two
leading eigenvectors of the matrix corresponding to a selected quality function
to split a network into three communities in a single step. In so doing, we
extend the recursive bipartitioning methods developed by Newman [Proc. Nat.
Acad. Sci. 103, 8577 (2006); Phys. Rev. E 74, 036104 (2006)] to allow one to
consider the best available two-way and three-way divisions at each recursive
step. We illustrate the method using simple "bucket brigade" examples and then
apply the algorithm to examine the community structures of the coauthorship
graph of network scientists and of U. S. Congressional networks inferred from
roll-call voting similarities.


title: Detecting Dark Matter annihilation lines with Fermi

abstract:
  Dark matter constitutes one of the most intriguing but so far unresolved
issues in physics today. In many extensions of the Standard Model the existence
of a stable Weakly Interacting Massive Particle (WIMP) is predicted. The WIMP
is an excellent dark matter particle candidate and one of the most interesting
scenarios include an annihilation of two WIMPs into two gamma-rays. If the
WIMPs are assumed to be non-relativistic, the resulting photons will both have
an energy equal to the mass of the WIMP and manifest themselves as a
monochromatic spectral line in the energy spectrum. This type of signal would
represent a "smoking gun" for dark matter, since no other known astrophysical
process should be able to produce it. In these proceedings we give an overview
of the different approaches to a search for dark matter lines that the
Fermi-LAT collaboration is pursuing and the various challenges involved.


title: Minoration de la hauteur de Neron-Tate sur les surfaces abeliennes

abstract:
  This paper contains results concerning a conjecture made by Lang and
Silverman predicting a lower bound for the canonical height on abelian
varieties of dimension 2 over number fields. The method used here is a local
height decomposition. We derive as corollaries uniform bounds on the number of
torsion points on families of abelian surfaces and on the number of rational
points on families of genus 2 curves.


title: On the QCD phase structure from effective models

abstract:
  Some recent theoretical developments of the QCD phase diagram are summarized.
Chiral symmetry restoration and the confinement/deconfinement transition at
nonzero temperature and quark densities are analyzed in the framework of an
effective linear sigma model with three light quark flavors. The sensitivity of
the chiral transition as well as the existence of a critical end point in the
phase diagram on the value of the sigma mass is explored. The influence of the
axial anomaly on the chiral critical surface is addressed. Finally, the
modifications by the inclusion of the Polyakov loop on the phase structure are
investigated.


title: High Redshift Metals I.: The Decline of C IV at z > 5.3

abstract:
  We present the results from our search for C IV in the intergalactic medium
at redshifts z=5.3-6.0. We have observed four z~6 QSOs with Keck/NIRSPEC in
echelle mode. The data are the most sensitive yet taken to search for C IV at
these redshifts, being 50% complete at column densities log(N_{CIV})=13.4. We
find no C IV systems in any of the four sightlines. Taking into account our
completeness, this translates into a decline in the number density of C IV
absorbers in the range 13.0 < log(N_{CIV}) < 15.0 of at least a factor 4.4 (95%
confidence) from z~2-4.5, where the number density is relatively constant. We
use our lack of detections to set limits on the slope and normalization of the
column density distribution at z=5.3-6.0. The rapid evolution of C IV at these
redshifts suggests that the decrease in the number density may largely be due
to ionization effects, in which case many of the metals in the z~4.5 IGM could
already be in place at z~5.3, but in a lower ionization state. The lack of weak
systems in our data, combined with the presence of strong C IV absorbers along
at least one other sightline, further suggests that there may be large-scale
variations in the enrichment and/or ionization state of the z~6 IGM, or that C
IV absorbers at these redshifts are associated with rare, UV-bright
star-forming galaxies.


title: Differentiability of the arithmetic volume function

abstract:
  We introduce the positive intersection product in Arakelov geometry and prove
that the arithmetic volume function is continuously differentiable. As
applications, we compute the distribution function of the asymptotic measure of
a Hermitian line bundle and several other arithmetic invariants.


title: Diffusive behavior from a quantum master equation

abstract:
  We study a general class of translation invariant quantum Markov evolutions
for a particle on $\bbZ^d$. The evolution consists of free flow, interrupted by
scattering events. We assume spatial locality of the scattering events and
exponentially fast relaxation of the momentum distribution. It is shown that
the particle position diffuses in the long time limit. This generalizes
standard results about central limit theorems for classical (non-quantum)
Markov processes.


title: Metric Renormalization in General Relativity

abstract:
  The averaging problem in general relativity concerns the difficulty of
defining meaningful averages of tensor quantities and we consider various
aspects of the problem. We first address cosmological backreaction which arises
because the averaged Einstein tensor is not the same as the Einstein tensor of
the averaged metric. It has been suggested that backreaction might account for
the dark energy. We show numerically in the Buchert formalism that the
corrections from (quasi)linear perturbations are only of the order of 10^-5 and
act as a dark matter. We then focus on constructing averaged metrics and
present a generally covariant averaging process which decomposes the metric
into Vielbeins and parallel transports them with a relativistic Wegner-Wilson
operator to a single point where they can then be averaged. The Vielbeins are
chosen in a Lagrangian formalism. The functionality of the process is
demonstrated in specific examples in two and three space dimensions. This
involves the numerical solution of partial differential equations by the aid of
the simulation toolkit Gascoigne.


title: Almost prime values of the order of elliptic curves over finite fields

abstract:
  Let $E$ be an elliptic curve over $\Q$ without complex multiplication, and
which is not isogenous to a curve with non-trivial rational torsion. For each
prime $p$ of good reduction, let $|E(\F_p)|$ be the order of the group of
points of the reduced curve over $\F_p$. We prove in this paper that, under the
GRH, there are at least $2.778 C_E^{\rm twin} x / (\log{x})^2$ primes $p$ such
that $|E(\F_p)|$ has at most 8 prime factors, counted with multiplicity. This
improves previous results of Steuding & Weng and Murty & Miri. This is also the
first result where the dependence on the conjectural constant $C_E^{\rm twin}$
appearing in the twin prime conjecture for elliptic curves (also known as
Koblitz's conjecture) is made explicit. This is achieved by sieving a slightly
different sequence than the one used by previous authors. By sieving the same
sequence and using Selberg's linear sieve, we can also improve the constant
appearing in the upper bound for the number of primes $p$ such that $|E(\F_p)|$
is prime. Finally, we remark that our results still hold under an hypothesis
weaker than the GRH.


title: Conformal self-dual fields

abstract:
  Conformal self-dual fields in flat space-time of even dimension greater than
or equal to four are studied. Ordinary-derivative formulation of such fields is
developed. Gauge invariant Lagrangian with conventional kinetic terms and
corresponding gauge transformations are obtained. Gauge symmetries are realized
by involving the Stueckelberg fields. Realization of global conformal
symmetries is obtained. Light-cone gauge Lagrangian is found. Also, we
demonstrate use of the light-cone gauge for counting of on-shell degrees of
freedom of the conformal self-dual fields.


title:
Transverse-momentum resummation: a perturbative study of Z production at
  the Tevatron

abstract:
  We consider transverse-momentum (q_T) resummation for Drell--Yan lepton pair
production in hadron collisions. At small values of q_T, the
logarithmically-enhanced QCD contributions are resummed up to next-to-leading
logarithmic accuracy. At intermediate and large values of q_T, resummation is
consistently combined with the fixed-order perturbative result. We present
numerical results for e^+e^- pairs from the decay of Z bosons produced at
Tevatron energies. We perform a detailed study of the scale dependence of the
results to estimate the corresponding perturbative uncertainty. We comment on
the comparison with the available Tevatron data.


title: Universality in Complex Wishart ensembles: The 1 cut case

abstract:
  We studied universality of Wishart ensembles whose covariance matrix has 2
distinct eigenvalues and the number of each of these eigenvalue goes to
infinity in the asymptotic limit. In this case, the limiting eigenvalue
distribution can be supported on 1 or 2 disjoint intervals. In our previous
work the case when the support consists of 2 intervals was studied. This paper
complements our previous analysis and studied the case when the support
consists of a single interval. By using Riemann-Hilbert analysis, we have shown
that under proper rescaling of the eigenvalues, the limiting correlation kernel
is given by the sine kernel and the Airy kernel in the bulk and the edge of the
spectrum respectively. As a consequence, the behavior of the largest eigenvalue
in this model is described by the Tracy-Widom distribution.


title: Subjet distributions in deep inelastic scattering at HERA

abstract:
  Subjet distributions were measured in neutral current deep inelastic ep
scattering with the ZEUS detector at HERA using an integrated luminosity of
81.7 pb-1. Jets were identified using the kT cluster algorithm in the
laboratory frame. Subjets were defined as jet-like substructures identified by
a reapplication of the cluster algorithm at a smaller value of the resolution
parameter ycut. Measurements of subjet distributions for jets with exactly two
subjets for ycut=0.05 are presented as functions of observables sensitive to
the pattern of parton radiation and to the colour coherence between the initial
and final states. Perturbative QCD predictions give an adequate description of
the data.


title: Three lectures on 3-algebras

abstract:
  These notes are based on lectures given in Valencia in October 2008 and in
Stockholm in November 2008, in the framework of the Nordita workshop
"Geometrical aspects of String Theory". We introduce the notion of a metric
3-Lie algebra and review some of the classification results. We explain the
deconstruction of metric 3-Lie algebras in Lie algebraic terms and introduce a
general framework in which to describe other 3-algebras of relevance in the
description of three-dimensional superconformal Chern-Simons theories,
particularly those with N=6. The emphasis throughout is on the general ideas
and concrete examples.


title: The thermopower and Nernst Effect in graphene in a magnetic field

abstract:
  We report measurements of the thermopower $S$ and Nernst signal $S_{yx}$ in
graphene in a magnetic field $H$. Both quantities show strong quantum
oscillations vs. the gate voltage $V_g$. Our measurements for Landau Levels of
index $n\ne 0$ are in quantitative agreement with the edge-current model of
Girvin and Jonson (GJ). The inferred off-diagonal thermoelectric conductivity
$\alpha_{yx}$ comes close to the quantum of Amps per Kelvin. At the Dirac point
($n=0$), however, the width of the peak in $\alpha_{yx}$ is very narrow. We
discuss features of the thermoelectric response at the Dirac point including
the enhanced Nernst signal.


title: Vibration Spectra of the $m$-Tree Fractal

abstract:
  We introduce a family of post-critically finite fractal trees indexed by the
number of branches they possess. Then we produce a Laplacian operator on graph
approximations to these fractals and use spectral decimation to describe the
spectrum of the Laplacian on these trees. Lastly we consider the behavior of
the spectrum as the number of branches increases.


title: Minimax Trees in Linear Time

abstract:
  A minimax tree is similar to a Huffman tree except that, instead of
minimizing the weighted average of the leaves' depths, it minimizes the maximum
of any leaf's weight plus its depth. Golumbic (1976) introduced minimax trees
and gave a Huffman-like, $\Oh{n \log n}$-time algorithm for building them.
Drmota and Szpankowski (2002) gave another $\Oh{n \log n}$-time algorithm,
which checks the Kraft Inequality in each step of a binary search. In this
paper we show how Drmota and Szpankowski's algorithm can be made to run in
linear time on a word RAM with (\Omega (\log n))-bit words. We also discuss how
our solution applies to problems in data compression, group testing and circuit
design.


title: Theory of measurement-based quantum computing

abstract:
  In the study of quantum computation, data is represented in terms of linear
operators which form a generalized model of probability, and computations are
most commonly described as products of unitary transformations, which are the
transformations which preserve the quality of the data in a precise sense. This
naturally leads to "unitary circuit models", which are models of computation in
which unitary operators are expressed as a product of "elementary" unitary
transformations. However, unitary transformations can also be effected as a
composition of operations which are not all unitary themselves: the "one-way
measurement model" is one such model of quantum computation.
  In this thesis, we examine the relationship between representations of
unitary operators and decompositions of those operators in the one-way
measurement model. In particular, we consider different circumstances under
which a procedure in the one-way measurement model can be described as
simulating a unitary circuit, by considering the combinatorial structures which
are common to unitary circuits and two simple constructions of one-way based
procedures. These structures lead to a characterization of the one-way
measurement patterns which arise from these constructions, which can then be
related to efficiently testable properties of graphs. We also consider how
these characterizations provide automatic techniques for obtaining complete
measurement-based decompositions, from unitary transformations which are
specified by operator expressions bearing a formal resemblance to path
integrals. These techniques are presented as a possible means to devise new
algorithms in the one-way measurement model, independently of algorithms in the
unitary circuit model.


title: How to eat 4/9 of a pizza

abstract:
  Given two players alternately picking pieces of a pizza sliced by radial
cuts, in such a way that after the first piece is taken every subsequent chosen
piece is adjacent to some previously taken piece, we provide a strategy for the
starting player to get 4/9 of the pizza. This is best possible and settles a
conjecture of Peter Winkler.


title: Intriguing sets of partial quadrangles

abstract:
  The point-line geometry known as a \textit{partial quadrangle} (introduced by
Cameron in 1975) has the property that for every point/line non-incident pair
$(P,\ell)$, there is at most one line through $P$ concurrent with $\ell$. So in
particular, the well-studied objects known as \textit{generalised quadrangles}
are each partial quadrangles. An \textit{intriguing set} of a generalised
quadrangle is a set of points which induces an equitable partition of size two
of the underlying strongly regular graph. We extend the theory of intriguing
sets of generalised quadrangles by Bamberg, Law and Penttila to partial
quadrangles, which surprisingly gives insight into the structure of hemisystems
and other intriguing sets of generalised quadrangles.


title:
Light propagation in statistically homogeneous and isotropic dust
  universes

abstract:
  We derive the redshift and the angular diameter distance in rotationless dust
universes which are statistically homogeneous and isotropic, but have otherwise
arbitrary geometry. The calculation from first principles shows that the
Dyer-Roeder approximation does not correctly describe the effect of clumping.
Instead, the redshift and the distance are determined by the average expansion
rate, the matter density today and the null geodesic shear. In particular, the
position of the CMB peaks is consistent with significant spatial curvature
provided the expansion history is sufficiently close to the spatially flat
LambdaCDM model.


title: Nonperturbative corrections from an s-channel approach

abstract:
  We report on studies of multi-parton corrections from nonlocal operator
expansion.
  We discuss relations between eikonal-line matrix elements and parton
distributions, and present an illustration for initial-state collinear
evolution.


title:
A Data Model for Integrating Heterogeneous Medical Data in the
  Health-e-Child Project

abstract:
  There has been much research activity in recent times about providing the
data infrastructures needed for the provision of personalised healthcare. In
particular the requirement of integrating multiple, potentially distributed,
heterogeneous data sources in the medical domain for the use of clinicians has
set challenging goals for the healthgrid community. The approach advocated in
this paper surrounds the provision of an Integrated Data Model plus links
to/from ontologies to homogenize biomedical (from genomic, through cellular,
disease, patient and population-related) data in the context of the EC
Framework 6 Health-e-Child project. Clinical requirements are identified, the
design approach in constructing the model is detailed and the integrated model
described in the context of examples taken from that project. Pointers are
given to future work relating the model to medical ontologies and challenges to
the use of fully integrated models and ontologies are identified.