title:
LAW: A Tool for Improved Productivity with High-Performance Linear
  Algebra Codes. Design and Applications

abstract:
  LAPACK and ScaLAPACK are arguably the defacto standard libraries among the
scientific community for solving linear algebra problems on sequential,
shared-memory and distributed-memory architectures. While ease of use was a
major design goal for the ScaLAPACK project; with respect to its predecessor
LAPACK; it is still a non-trivial exercise to develop a new code or modify an
existing LAPACK code to exploit processor grids, distributed-array descriptors
and the associated distributed-memory ScaLAPACK/PBLAS routines. In this paper,
we introduce what we believe will be an invaluable development tool for the
scientific code developer, which exploits ad-hoc polymorphism, derived-types,
optional arguments, overloaded operators and conditional compilation in Fortran
95, to provide wrappers to a subset of common linear algebra kernels. These
wrappers are introduced to facilitate the abstraction of low-level details
which are irrelevant to the science being performed, such as target platform
and execution model. By exploiting this high-level library interface, only a
single code source is required with mapping onto a diverse range of execution
models performed at link-time with no user modification. We conclude with a
case study whereby we describe application of the LAW library in the
implementation of the well-known Chebyshev Matrix Exponentiation algorithm for
Hermitian matrices.


title: Nuclear PDFs from neutrino deep inelastic scattering

abstract:
  We study nuclear effects in charged current deep inelastic neutrino-iron
scattering in the frame-work of a chi^2 analysis of parton distribution
functions. We extract a set of iron PDFs and show that under reasonable
assumptions it is possible to constrain the valence, light sea and strange
quark distributions. Our iron PDFs are used to compute x_{Bj}-dependent and
Q^2-dependent nuclear correction factors for iron structure functions which are
required in global analyses of free nucleon PDFs. We compare our results with
nuclear correction factors from neutrino-nucleus scattering models and
correction factors for charged lepton-iron scattering. We find that, except for
very high x_{Bj}, our correction factors differ in both shape and magnitude
from the correction factors of the models and charged-lepton scattering.


title:
Report on an all-sky LIGO search for periodic gravitational waves in the
  S4 data

abstract:
  We report on an all-sky search with the LIGO detectors for periodic
gravitational waves in the frequency range 50-1000 Hz and having a negative
frequency time derivative with magnitude between zero and $10^{-8}$ Hz/s. Data
from the fourth LIGO science run have been used in this search. Three different
semi-coherent methods of summing strain power were applied. Observing no
evidence for periodic gravitational radiation, we report upper limits on strain
amplitude and interpret these limits to constrain radiation from rotating
neutron stars.


title:
Derivation via free energy conservation constraints of gyrofluid
  equations with finite-gyroradius electromagnetic nonlinearities

abstract:
  The derivation of electromagnetic gyrofluid equations is made systematic by
using the Hermite polynomial form of the underlying delta-f gyrokinetic
distribution function. The gyrokinetic free-energy functional is explicitly
used to set up the model. The gyrofluid free energy follows directly. The
interaction term in the gyrokinetic Lagrangian is used to obtain the gyrofluid
counterpart, from which the polarisation equation follows. One closure rule is
decided for taking moments over the kinetic gyroaveraging operator. These steps
fix the rest of the derivation of the conservative part of the gyrofluid
equations. Dissipation is then added in a form to obtain positive definite
dissipation and to obtain the collisional fluid equations in their appropriate
limit. Existing results are recovered, with the addition of a completely
consistent model for finite gyroradius effects in the nonlinearities
responsible for magnetic reconnection.


title: Chiral Symmetry Breaking in Brane Models

abstract:
  We discuss the chiral symmetry breaking in general intersecting Dq/Dp brane
models consisting of N_c Dq-branes and a single Dp-brane with an s-dimensional
intersection. There exists a QCD-like theory localized at the intersection and
the Dq/Dp model gives a holographic description of it. The rotational symmetry
of directions transverse to both of the Dq and Dp-branes can be identified with
a chiral symmetry, which is non-Abelian for certain cases. The asymptotic
distance between the Dq-branes and the Dp-brane corresponds to a quark mass. By
studying the probe Dp-brane dynamics in a Dq-brane background in the near
horizon and large N_c limit we find that the chiral symmetry is spontaneously
broken and there appear (pseudo-)Nambu-Goldstone bosons. We also discuss the
models at finite temperature.


title: Optical detection of single electron spin resonance in a quantum dot

abstract:
  We demonstrate optically detected spin resonance of a single electron
confined to a self-assembled quantum dot. The dot is rendered dark by resonant
optical pumping of the spin with a coherent laser. Contrast is restored by
applying a radio frequency (rf) magnetic field at the spin resonance. The
scheme is sensitive even to rf fields of just a few micro-T. In one case, the
spin resonance behaves exactly as a driven 3-level quantum system (a
lambda-system) with weak damping. In another, the dot exhibits remarkably
strong (67% signal recovery) and narrow (0.34 MHz) spin resonances with
fluctuating resonant positions, evidence of unusual dynamic processes of
non-Markovian character.


title:
The Lifshitz-Khalatnikov Kasner index parametrization and the Weyl
  Tensor

abstract:
  The scale invariant Petrov classification of the Weyl tensor is linked to the
scale invariant combination of the Kasner index constraints, and the
Lifshitz-Khalatnikov Kasner index parametrization scheme turns out to be a
natural way of adapting to this symmetry, while hiding the permutation symmetry
that is instead made manifest by the Misner parametrization scheme. While not
so interesting for the Kasner spacetime by itself, it gives a geometrical
meaning to the famous Kasner map transitioning between Kasner epochs and Kasner
eras, equivalently bouncing between curvature walls, in the BLK-Mixmaster
dynamics exhibited by spatially homogeneous cosmologies approaching the initial
cosmological singularity and the inhomogeneous generalization of this dynamics.


title: Anonymous Networking amidst Eavesdroppers

abstract:
  The problem of security against timing based traffic analysis in wireless
networks is considered in this work. An analytical measure of anonymity in
eavesdropped networks is proposed using the information theoretic concept of
equivocation. For a physical layer with orthogonal transmitter directed
signaling, scheduling and relaying techniques are designed to maximize
achievable network performance for any given level of anonymity. The network
performance is measured by the achievable relay rates from the sources to
destinations under latency and medium access constraints. In particular,
analytical results are presented for two scenarios:
  For a two-hop network with maximum anonymity, achievable rate regions for a
general m x 1 relay are characterized when nodes generate independent Poisson
transmission schedules. The rate regions are presented for both strict and
average delay constraints on traffic flow through the relay.
  For a multihop network with an arbitrary anonymity requirement, the problem
of maximizing the sum-rate of flows (network throughput) is considered. A
selective independent scheduling strategy is designed for this purpose, and
using the analytical results for the two-hop network, the achievable throughput
is characterized as a function of the anonymity level. The throughput-anonymity
relation for the proposed strategy is shown to be equivalent to an information
theoretic rate-distortion function.


title: Density Functional Theory for the Photoionization Dynamics of Uracil

abstract:
  Photoionization dynamics of the RNA base Uracil is studied in the framework
of Density Functional Theory (DFT). The photoionization calculations take
advantage of a newly developed parallel version of a multicentric approach to
the calculation of the electronic continuum spectrum which uses a set of
B-spline radial basis functions and a Kohn-Sham density functional hamiltonian.
Both valence and core ionizations are considered. Scattering resonances in
selected single-particle ionization channels are classified by the symmetry of
the resonant state and the peak energy position in the photoelectron kinetic
energy scale; the present results highlight once more the site specificity of
core ionization processes. We further suggest that the resonant structures
previously characterized in low-energy electron collision experiments are
partly shifted below threshold by the photoionization processes. A critical
evaluation of the theoretical results providing a guide for future experimental
work on similar biosystems.


title: Distributed Source Coding in the Presence of Byzantine Sensors

abstract:
  The distributed source coding problem is considered when the sensors, or
encoders, are under Byzantine attack; that is, an unknown group of sensors have
been reprogrammed by a malicious intruder to undermine the reconstruction at
the fusion center. Three different forms of the problem are considered. The
first is a variable-rate setup, in which the decoder adaptively chooses the
rates at which the sensors transmit. An explicit characterization of the
variable-rate achievable sum rates is given for any number of sensors and any
groups of traitors. The converse is proved constructively by letting the
traitors simulate a fake distribution and report the generated values as the
true ones. This fake distribution is chosen so that the decoder cannot
determine which sensors are traitors while maximizing the required rate to
decode every value. Achievability is proved using a scheme in which the decoder
receives small packets of information from a sensor until its message can be
decoded, before moving on to the next sensor. The sensors use randomization to
choose from a set of coding functions, which makes it probabilistically
impossible for the traitors to cause the decoder to make an error. Two forms of
the fixed-rate problem are considered, one with deterministic coding and one
with randomized coding. The achievable rate regions are given for both these
problems, and it is shown that lower rates can be achieved with randomized
coding.


title: Systematics and background suppression in the KATRIN experiment

abstract:
  Recent neutrino mass experiments at Mainz and Troitsk using tritium
beta-decay have reached their sensitivity potential, yielding upper limits of
about 2 eV/c^2 for the electron antineutrino mass. The KArlsruhe TRItium
Neutrino experiment (KATRIN), designed to reach a sensitivity of 0.2 eV/c^2
(90% C.L.), will improve the signal rate by a factor of about 100 with respect
to previous experiments while maintaining the same low background level at an
enhanced energy resolution of 0.93 eV of the spectrometer which is scaled up by
a factor of 10 in linear dimensions. This low background rate can only be
achieved by active and passive reduction of the background components induced
by the spectrometer itself and in the detector region. Furthermore, sources of
systematic errors such as energy losses inside the tritium source or
fluctuations of the energy scale of the spectrometer need to be carefully
controlled and analysed. An overview of KATRIN's method to reduce the
background rate and to determine the systematics as well as the sensitivity on
the neutrino mass will be presented.


title: U-Duality and the Compactified Gauss-Bonnet Term

abstract:
  We present the complete toroidal compactification of the Gauss-Bonnet
Lagrangian from D dimensions to (D-n) dimensions. Our goal is to investigate
the resulting action from the point of view of the "U-duality" symmetry
SL(n+1,R) which is present in the tree-level Lagrangian when D-n=3. The
analysis builds upon and extends the investigation of the paper
[arXiv:0706.1183], by computing in detail the full structure of the
compactified Gauss-Bonnet term, including the contribution from the dilaton
exponents. We analyze these exponents using the representation theory of the
Lie algebra sl(n+1,R) and determine which representation seems to be the
relevant one for quadratic curvature corrections. By interpreting the result of
the compactification as a leading term in a large volume expansion of an
SL(n+1,Z)-invariant action, we conclude that the overall exponential dilaton
factor should not be included in the representation structure. As a
consequence, all dilaton exponents correspond to weights of sl(n+1,R), which,
nevertheless, remain on the positive side of the root lattice.


title: Physics at SuperB

abstract:
  Flavour will play a crucial role in understanding physics beyond the Standard
Model. Progress in developing a future programme to investigate this central
area of particle physics has recently passed a milestone, with the completion
of the conceptual design report for SuperB, a very high luminosity, asymmetric
e+e- collider. This article summarizes the important role of SuperB in
understanding new physics in the LHC era.


title: The origin of galactic cosmic rays

abstract:
  The origin of galactic cosmic rays is one of the most interesting unsolved
problems in astroparticle physics. Experimentally, the problem is attacked by a
multi-disciplinary effort, namely by direct measurements of cosmic rays above
the atmosphere, by air shower observations, and by the detection of TeV
$\gamma$ rays. Recent experimental results are presented and their implications
on the contemporary understanding of the origin of galactic cosmic rays are
discussed.


title: Generic Absorbing Transition in Coevolution Dynamics

abstract:
  We study a coevolution voter model on a network that evolves according to the
state of the nodes. In a single update, a link between opposite-state nodes is
rewired with probability $p$, while with probability $1-p$ one of the nodes
takes its neighbor's state. A mean-field approximation reveals an absorbing
transition from an active to a frozen phase at a critical value
$p_c=\frac{\mu-2}{\mu-1}$ that only depends on the average degree $\mu$ of the
network. The approach to the final state is characterized by a time scale that
diverges at the critical point as $\tau \sim |p_c-p|^{-1}$. We find that the
active and frozen phases correspond to a connected and a fragmented network
respectively. We show that the transition in finite-size systems can be seen as
the sudden change in the trajectory of an equivalent random walk at the
critical rewiring rate $p_c$, highlighting the fact that the mechanism behind
the transition is a competition between the rates at which the network and the
state of the nodes evolve.


title: Social Media as Windows on the Social Life of the Mind

abstract:
  This is a programmatic paper, marking out two directions in which the study
of social media can contribute to broader problems of social science:
understanding cultural evolution and understanding collective cognition. Under
the first heading, I discuss some difficulties with the usual, adaptationist
explanations of cultural phenomena, alternative explanations involving network
diffusion effects, and some ways these could be tested using social-media data.
Under the second I describe some of the ways in which social media could be
used to study how the social organization of an epistemic community supports
its collective cognitive performance.


title: Near-horizon microstates of the D1-D5-P black hole

abstract:
  We construct probe solutions in the attractor background of the
five-dimensional D1-D5-P black hole which represent near-horizon microstates in
the limit of large D1-charge. These generalize the corresponding solutions
considered by Gaiotto, Strominger and Yin for the 4-dimensional D0-D4 black
hole. Using U-duality and a 4D-5D connection, we argue that the relevant
configurations are bound states of D1-branes that have expanded through the
Myers effect to form a Kaluza-Klein monopole wrapping the black hole horizon.
We show that these branes experience a magnetic field on their moduli space,
and that the degeneracy of lowest Landau levels reproduces the
Bekenstein-Hawking entropy.


title: Tackling master equations with a flux loop transform

abstract:
  A procedure is introduced which allows to represent the dynamics of a
non-equilibrium system violating detailed balance by its steady state loop
fluxes. It is shown that detailed balance is restored in this representation,
such that the non-equilibrium steady state follows a simple Boltzmann
distribution. A novel algorithm for the construction of the steady state
densities naturally emerges, as well as an expression for a 'free energy'
functional which attains a minimum in the steady state.


title: Joule heating in the cooling of magnetized neutron stars

abstract:
  We present 2D simulations of the cooling of neutron stars with strong
magnetic fields (B \geq 10^{13} G). We solve the diffusion equation in axial
symmetry including the state of the art microphysics that controls the cooling
such as slow/fast neutrino processes, superfluidity, as well as possible
heating mechanisms. We study how the cooling curves depend on the the magnetic
field strength and geometry. Special attention is given to discuss the
influence of magnetic field decay. We show that Joule heating effects are very
large and in some cases control the thermal evolution. We characterize the
temperature anisotropy induced by the magnetic field for the early and late
stages of the evolution of isolated neutron stars.


title: Casimir energy and entropy between dissipative mirrors

abstract:
  We discuss the Casimir effect between two identical, parallel slabs,
emphasizing the role of dissipation and temperature. Starting from quite
general assumptions, we analyze the behavior of the Casimir entropy in the
limit T->0 and link it to the behavior of the slab's reflection coefficients at
low frequencies. We also derive a formula in terms of a sum over modes, valid
for dissipative slabs that can be interpreted in terms of a damped quantum
oscillator.


title: Impact of interactions on human dynamics

abstract:
  Queueing theory has been recently proposed as a framework to model the heavy
tailed statistics of human activity patterns. The main predictions are the
existence of a power-law distribution for the interevent time of human actions
and two decay exponents $\alpha=1$ and $\alpha=3/2$. Current models lack,
however, a key aspect of human dynamics, i.e. several tasks require, or are
determined by, interactions between individuals. Here we introduce a minimal
queueing model of human dynamics that already takes into account human-human
interactions. To achieve large scale simulations we obtain a coarse-grained
version of the model, allowing us to reach large interevent times and reliable
scaling exponents estimations. Using this we show that the interevent
distribution of interacting tasks exhibit the scaling exponents $\alpha=2$, 3/2
and a series of numerable values between 3/2 and 1. This work demonstrates
that, within the context of queueing models of human dynamics, interactions
change the exponent of the power-law distributed interevent times. Beyond the
study of human dynamics, these results are relevant to systems where the event
of interest consists of the simultaneous occurrence of two (or more) events.


title: Drip Paintings and Fractal Analysis

abstract:
  It has been claimed [1-6] that fractal analysis can be applied to
unambiguously characterize works of art such as the drip paintings of Jackson
Pollock. This academic issue has become of more general interest following the
recent discovery of a cache of disputed Pollock paintings. We definitively
demonstrate here, by analyzing paintings by Pollock and others, that fractal
criteria provide no information about artistic authenticity. This work has also
led to two new results in fractal analysis of more general scientific
significance. First, the composite of two fractals is not generally scale
invariant and exhibits complex multifractal scaling in the small distance
asymptotic limit. Second the statistics of box-counting and related staircases
provide a new way to characterize geometry and distinguish fractals from
Euclidean objects.


title: A precise formulation of the third law of thermodynamics

abstract:
  The third law of thermodynamics is formulated precisely: all points of the
state space of zero temperature $\Gamma_0$ are physically adiabatically
inaccessible from the state space of a simple system. In addition to implying
the unattainability of absolute zero in finite time (or "by a finite number of
operations"), it admits as corollary, under a continuity assumption, that all
points of $\Gamma_0$ are adiabatically equivalent. We argue that the third law
is universally valid for all macroscopic systems which obey the laws of quantum
mechanics and/or quantum field theory. We also briefly discuss why a precise
formulation of the third law for black holes remains an open problem.


title:
Harmonic cosmology: How much can we know about a universe before the big
  bang?

abstract:
  Quantum gravity may remove classical space-time singularities and thus reveal
what a universe at and before the big bang could be like. In loop quantum
cosmology, an exactly solvable model is available which allows one to address
precise dynamical coherent states and their evolution in such a setting. It is
shown here that quantum fluctuations before the big bang are generically
unrelated to those after the big bang. A reliable determination of pre-big bang
quantum fluctuations would require exceedingly precise observations.


title: On the quasi-derivation relation for multiple zeta values

abstract:
  Recently, Masanobu Kaneko introduced a conjecture on an extension of the
derivation relation for multiple zeta values. The goal of the present paper is
to present a proof of this conjecture by reducing it to a class of relations
for multiple zeta values studied by Kawashima. In addition, some algebraic
aspects of the quasi-derivation operator $\partial_n^{(c)}$ on $\mathbb{Q}<
x,y>$, which was defined by modeling a Hopf algebra developed by Connes and
Moscovici, will be presented.


title: Weinberg like sum rules revisited

abstract:
  The generalized Weinberg sum rules containing the difference of isovector
vector and axial-vector spectral functions saturated by both finite and
infinite number of narrow resonances are considered. We summarize the status of
these sum rules and analyze their overall agreement with phenomenological
Lagrangians, low-energy relations, parity doubling, hadron string models, and
experimental data.


title: Constraining DM properties with SPI

abstract:
  Using the high-resolution spectrometer SPI on board the International
Gamma-Ray Astrophysics Laboratory (INTEGRAL), we search for a spectral line
produced by a dark matter(DM) particle with a mass in the range 40keV < M_DM <
14MeV, decaying in the DM halo of the Milky Way. To distinguish the DM decay
line from numerous instrumental lines found in the SPI background spectrum, we
study the dependence of the intensity of the line signal on the offset of the
SPI pointing from the direction toward the Galactic Centre. After a critical
analysis of the uncertainties of the DM density profile in the inner Galaxy, we
find that the intensity of the DM decay line should decrease by at least a
factor of 3 when the offset from the Galactic Centre increases from 0 to 180
degrees. We find that such a pronounced variation of the line flux across the
sky is not observed for any line, detected with a significance higher than 3
sigma in the SPI background spectrum. Possible DM decay origin is not ruled out
only for the unidentified spectral lines, having low (~3 sigma) significance or
coinciding in position with the instrumental ones. In the energy interval from
20 keV to 7 MeV, we derive restrictions on the DM decay line flux, implied by
the (non-)detection of the DM decay line. For a particular DM candidate, the
sterile neutrino of mass MDM, we derive a bound on the mixing angle.


title: Di-photon Higgs Decay in SUSY with CP Violation

abstract:
  Physical Higgs particles in the Minimal Supersymmetric Standard Model (MSSM)
with explicit CP violation are CP mixed states. The decay of these Higgs
particles can be analysed to study the CP properties of the MSSM. In the
present work we consider the di-photon channel of the lightest neutral Higgs
boson for this purpose. Compared to earlier studies on effects of
scalar/pseudo-scalar mixing, our analysis also investigates the effect due to
Higgs-sfermion-sfermion couplings along with that of mixing. We find that a
light stop may have a strong impact on the width and Branching Ratio (BR) of
the decay process H1 --> gamma.gamma, whereas other light sparticles have only
little influence. In some regions of the MSSM parameter space with large
CP-violating phase phi-mu ~ 90 deg a light (~ 200 GeV) stop can change the
di-photon BR by more than 50 % compared to the case with heavy (~ 1 TeV) stop
and otherwise same MSSM parameters.


title: Do Incomplete GUT Multiplets Always Spoil Unification?

abstract:
  We consider a new class of light vectorlike exotics with fractional electric
charge which do not come in complete representations of a grand unified gauge
group, and are nevertheless compatible with gauge coupling unification and
other predictions from Grand Unified Theories. Such states naturally arise in
orbifold constructions of the heterotic string. Some aspects of their
phenomenology and the consequences for the LHC are explored.


title:
Differences in Solution Behavior among Four Semiconductor-Binding
  Peptides

abstract:
  Recent experiments have identified peptides with adhesion affinity for GaAs
and Si surfaces. Here we use all-atom Monte Carlo (MC) simulations with
implicit solvent to investigate the behavior in aqueous solution of four such
peptides, all with 12 residues. At room temperature, we find that all the four
peptides are largely unstructured, which is consistent with experimental data.
At the same time, we find that one of the peptides is structurally different
and more flexible, compared to the others. This finding points at structural
differences as a possible explanation for differences in adhesion properties
between these peptides. By also analyzing designed mutants of two of the
peptides, an experimental test of this hypothesis is proposed.


title:
Time-resolved investigation of magnetization dynamics of arrays of
  non-ellipsoidal nanomagnets with a non-uniform ground state

abstract:
  We have performed time-resolved scanning Kerr microscopy (TRSKM) measurements
upon arrays of square ferromagnetic nano-elements of different size and for a
range of bias fields. The experimental results were compared to micromagnetic
simulations of model arrays in order to understand the non-uniform precessional
dynamics within the elements. In the experimental spectra two branches of
excited modes were observed to co-exist above a particular bias field. Below
the so-called crossover field, the higher frequency branch was observed to
vanish. Micromagnetic simulations and Fourier imaging revealed that modes from
the higher frequency branch had large amplitude at the center of the element
where the effective field was parallel to the bias field and the static
magnetization. Modes from the lower frequency branch had large amplitude near
the edges of the element perpendicular to the bias field. The simulations
revealed significant canting of the static magnetization and the effective
field away from the direction of the bias field in the edge regions. For the
smallest element sizes and/or at low bias field values the effective field was
found to become anti-parallel to the static magnetization. The simulations
revealed that the majority of the modes were de-localized with finite amplitude
throughout the element, while the spatial character of a mode was found to be
correlated with the spatial variation of the total effective field and the
static magnetization state. The simulations also revealed that the frequencies
of the edge modes are strongly affected by the spatial distribution of the
static magnetization state both within an element and within its nearest
neighbors.


title:
Identification of Characteristic Protein Folding Channels in a
  Coarse-Grained Hydrophobic-Polar Peptide Model

abstract:
  Folding channels and free-energy landscapes of hydrophobic-polar
heteropolymers are discussed on the basis of a minimalistic off-lattice
coarse-grained model. We investigate how rearrangements of hydrophobic and
polar monomers in a heteropolymer sequence lead to completely different folding
behaviors. Studying three exemplified sequences with the same content of
hydrophobic and polar residues, we can reproduce within this simple model
two-state folding, folding through intermediates, as well as metastability.


title: Quantum Hall effect in graphene: A functional determinant approach

abstract:
  We start the paper with a brief presentation of the main characteristics of
graphene, and of the Dirac theory of massless fermions in 2+1 dimensions
obtained as the associated low-momentum effective theory, in the absence of
external fields. We then summarize the main steps needed to obtain the Hall
conductivity in the effective theory at finite temperature and density, with
emphasis on its dependence on the phase of the Dirac determinant selected
during the evaluation of the effective action. Finally, we discuss the
behavior, under gauge transformations, of the contribution due to the lowest
Landau level, and interpret gauge transformations as rotations of the
corresponding spinors around the magnetic field.

categories: hep-th cond-mat.mes-hall math-ph math.MP


title:
Phase Separation in Peptide Aggregation Processes - Multicanonical Study
  of a Mesoscopic Model

abstract:
  We have performed multicanonical computer simulations of a small system of
short protein-like heteropolymers and found that their aggregation transition
possesses similarities to first-order phase separation processes. Not being a
phase transition in the thermodynamic sense, the observed folding-binding
behavior exhibits fascinating features leading to the conclusion that the
temperature is no suitable control parameter in the transition region. More
formally, for such small systems the microcanonical interpretation is more
favorable than the typically used canonical picture.


title:
Extensions of discrete classical orthogonal polynomials beyond the
  orthogonality

abstract:
  It is well known that the family of Hahn polynomials
$\{h_n^{\alpha,\beta}(x;N)\}_{n\ge 0}$ is orthogonal with respect to a certain
weight function up to $N$. In this paper we present a factorization for Hahn
polynomials for a degree higher than $N$ and we prove that these polynomials
can be characterized by a $\Delta$-Sobolev orthogonality.
  We also present an analogous result for dual-Hahn, Krawtchouk, and Racah
polynomials and give the limit relations between them for all $n\in \XX N_0$.
Furthermore, in order to get this results for the Krawtchouk polynomials we
will get a more general property of orthogonality for Meixner polynomials.


title: Recent results in four-dimensional non-perturbative string theory

abstract:
  We review recent progress in understanding non-perturbative instanton
corrections to the hypermultiplet moduli space in type II string
compactifications on Calabi-Yau threefolds.


title: The concentration index of subharmonic functions of infinite order

abstract:
  The purpose of this paper is to introduce into consideration an analogue of
the concentration index in the class of subharmonic functions of infinite
order. The one in the case of finite order is used in the interpolation theory.


title:
Superlens imaging theory for anisotropic nanostructured metamaterials
  with broadband all-angle negative refraction

abstract:
  We show that a metamaterial consisting of aligned metallic nanowires in a
dielectric matrix has strongly anisotropic optical properties. For filling
ratio f<1/2, the composite medium shows two surface plasmon resonances (SPRs):
the transverse and longitudinal SPR with wavelengths lambda_t<lambda_l. For
lambda>lambda_l, the longitudinal SPR, the material exhibits Re epsilon_l<0, Re
epsilon_t>0, relative to the nanowires axis, enabling the achievement of
broadband all-angle negative refraction and superlens imaging. An imaging
theory of superlens made of these media is established. High performance
systems made with Au, Ag or Al nanowires in nanoporous templates are designed
and predicted to work from the infrared up to ultraviolet frequencies.


title:
Spectral analysis of LMC X-2 with XMM/Newton: unveiling the emission
  process in the extragalactic Z-source

abstract:
  We present the results of the analysis of an archival observation of LMC X-2
performed with XMM/Newton. The spectra taken by high-precision instruments have
never been analyzed before. We find an X-ray position for the source that is
inconsistent with the one obtained by ROSAT, but in agreement with the Einstein
position and that of the optical counterpart. The correlated spectral and
timing behaviour of the source suggests that the source is probably in the
normal branch of its X-ray color-color diagram. The spectrum of the source can
be fitted with a blackbody with a temperature 1.5 keV plus a disk blackbody at
0.8 keV. Photoelectric absorption from neutral matter has an equivalent
hydrogen column of 4 x 10^{20} cm^{-2}. An emission line, which we identify as
the O VIII Lyman alpha line, is detected, while no feature due to iron is
detected in the spectrum. We argue that the emission of this source can be
straightforwardly interpreted as a sum of the emission from a boundary layer
between the NS and the disc and a blackbody component coming from the disc
itself. Other canonical models that are used to fit Z-sources do not give a
satisfactory fit to the data. The detection of the O VIII emission line (and
the lack of detection of lines in the iron region) can be due to the fact that
the source lies in the Large Magellanic Cloud.


title: Is Gravitational Lensing by Intercluster Filaments Always Negligible?

abstract:
  Intercluster filaments negligibly contribute to the weak lensing signal in
general relativity (GR), $\gamma_{N}\sim 10^{-4}-10^{-3}$. In the context of
relativistic modified Newtonian dynamics (MOND) introduced by Bekenstein,
however, a single filament inclined by $\approx 45^\circ$ from the line of
sight can cause substantial distortion of background sources pointing towards
the filament's axis ($\kappa=\gamma=(1-A^{-1})/2\sim 0.01$); this is rigorous
for infinitely long uniform filaments, but also qualitatively true for short
filaments ($\sim 30$Mpc), and even in regions where the projected matter
density of the filament is equal to zero. Since galaxies and galaxy clusters
are generally embedded in filaments or are projected on such structures, this
contribution complicates the interpretation of the weak lensing shear map in
the context of MOND. While our analysis is of mainly theoretical interest
providing order-of-magnitude estimates only, it seems safe to conclude that
when modeling systems with anomalous weak lensing signals, e.g. the "bullet
cluster" of Clowe et al., the "cosmic train wreck" of Abell 520 from Mahdavi et
al., and the "dark clusters" of Erben et al., filamentary structures might
contribute in a significant and likely complex fashion. On the other hand, our
predictions of a (conceptual) difference in the weak lensing signal could, in
principle, be used to falsify MOND/TeVeS and its variations.


title: Dark Matter Caustics in Galaxy Clusters

abstract:
  We interpret the recent gravitational lensing observations of Jee et al.
\cite{Jee} as first evidence for a {\it caustic} ring of dark matter in a
galaxy cluster. A caustic ring unavoidably forms when a cold collisionless flow
falls with net overall rotation in and out of a gravitational potential well.
Evidence for caustic rings of dark matter was previously found in the Milky Way
and other isolated spiral galaxies. We argue that galaxy clusters have at least
one and possibly two or three caustic rings. We calculate the column density
profile of a caustic ring in a cluster and show that it is consistent with the
observations of Jee et al.


title: Heavy sfermions in SUSY analysis at LHC and ILC

abstract:
  The physics potential of the Large Hadron Collider in combination with the
planned International Linear Collider is discussed for a difficult region of
supersymmetry that is characterized by scalar SUSY particles with masses around
2 TeV. Precision measurements of masses, cross sections and forward-backward
asymmetries allow to determine the fundamental supersymmetric parameters even
if only a small part of the spectrum is accessible. No assumptions on a
specific SUSY-breaking mechanism are imposed. Mass contraints for the
kinematically inaccessible particles can be derived.


title:
Breakdown of the Fermi-liquid regime in the 2D Hubbard model from a
  two-loop field-theoretical renormalization group approach

abstract:
  We analyze the particle-hole symmetric two-dimensional Hubbard model on a
square lattice starting from weak-to-moderate couplings by means of the
field-theoretical renormalization group (RG) approach up to two-loop order.
This method is essential in order to evaluate the effect of the
momentum-resolved anomalous dimension $\eta(\textbf{p})$ which arises in the
normal phase of this model on the corresponding low-energy single-particle
excitations. As a result, we find important indications pointing to the
existence of a non-Fermi liquid (NFL) regime at temperature $T\to 0$ displaying
a truncated Fermi surface (FS) for a doping range exactly in between the
well-known antiferromagnetic insulating and the $d_{x^2-y^2}$-wave singlet
superconducting phases. This NFL evolves as a function of doping into a
correlated metal with a large FS before the $d_{x^2-y^2}$-wave pairing
susceptibility finally produces the dominant instability in the low-energy
limit.


title:
Lifetime difference in D^0 - \bar{D^0} mixing within R-parity-violating
  SUSY

abstract:
  We re-examine constraints from the recent evidence for observation of the
lifetime difference in D^0 - \bar{D}^0 mixing on the parameters of
supersymmetric models with R-parity violation (RPV). We find that RPV SUSY can
give large negative contribution to the lifetime difference. We also discuss
the importance of the choice of weak or mass basis when placing the constraints
on RPV-violating couplings from flavor mixing experiments.


title: Pore-blockade Times for Field-Driven Polymer Translocation

abstract:
  We study pore blockade times for a translocating polymer of length $N$,
driven by a field $E$ across the pore in three dimensions. The polymer performs
Rouse dynamics, i.e., we consider polymer dynamics in the absence of
hydrodynamical interactions. We find that the typical time the pore remains
blocked during a translocation event scales as $\sim N^{(1+2\nu)/(1+\nu)}/E$,
where $\nu\simeq0.588$ is the Flory exponent for the polymer. In line with our
previous work, we show that this scaling behaviour stems from the polymer
dynamics at the immediate vicinity of the pore -- in particular, the memory
effects in the polymer chain tension imbalance across the pore. This result,
along with the numerical results by several other groups, violates the lower
bound $\sim N^{1+\nu}/E$ suggested earlier in the literature. We discuss why
this lower bound is incorrect and show, based on conservation of energy, that
the correct lower bound for the pore-blockade time for field-driven
translocation is given by $\eta N^{2\nu}/E$, where $\eta$ is the viscosity of
the medium surrounding the polymer.

categories: cond-mat.soft cond-mat.stat-mech physics.bio-ph q-bio.BM


title:
Ocean Planet or Thick Atmosphere: On the Mass-Radius Relationship for
  Solid Exoplanets with Massive Atmospheres

abstract:
  The bulk composition of an exoplanet is commonly inferred from its average
density. For small planets, however, the average density is not unique within
the range of compositions. Variations of a number of important planetary
parameters--which are difficult or impossible to constrain from measurements
alone--produce planets with the same average densities but widely varying bulk
compositions. We find that adding a gas envelope equivalent to 0.1%-10% of the
mass of a solid planet causes the radius to increase 5-60% above its gas-free
value. A planet with a given mass and radius might have substantial water ice
content (a so-called ocean planet) or alternatively a large rocky-iron core and
some H and/or He. For example, a wide variety of compositions can explain the
observed radius of GJ 436b, although all models require some H/He. We conclude
that the identification of water worlds based on the mass-radius relationship
alone is impossible unless a significant gas layer can be ruled out by other
means.


title: Topology of the Spin-polarized Charge Density in bcc and fcc Iron

abstract:
  We investigate the topology of the spin-polarized charge density in bcc and
fcc iron. While the total spin-density is found to possess the topology of the
non-magnetic prototypical structures, in some cases the spin-polarized
densities are characterized by unique topologies; for example, the
spin-polarized charge densities of bcc and high-spin fcc iron are atypical of
any known for non-magnetic materials. In these cases, the two spin-densities
are correlated: the spin-minority electrons have directional bond paths with
deep minima in the minority density, while the spin-majority electrons fill
these holes, reducing bond directionality. The presence of two distinct spin
topologies suggests that a well-known magnetic phase transition in iron can be
fruitfully reexamined in light of these topological changes. We show that the
two phase changes seen in fcc iron (paramagnetic to low-spin and low-spin to
high-spin) are different. The former follows the Landau symmetry-breaking
paradigm and proceeds without a topological transformation, while the latter
also involves a topological catastrophe.


title: Radiative Mechanism to Light Fermion Masses in the MSSM

abstract:
  In a previous work we have showed that the ${\cal Z}_{2}^{\prime}$ Symmetry,
imply that the light fermions, the electron and the quarks, $u,d$ and $s$, get
their masses only at one loop level. Here, we considere the more general
hypothesis for flavour mixing in the sfermion sector in the MSSM. Then, we
present our results to the masses of these light fermions and as a final result
we can explain why the $s$ quark is heavier than the $u,d$ quarks. This
mechanism is in agrement with the experimental constraint on the sfermion's
masses values.


title: Evidence for higher order QED in e+ e- pair production at RHIC

abstract:
  A new lowest order QED calculation for RHIC e+ e- pair production has been
carried out with a phenomenological treatment of the Coulomb dissociation of
the heavy ion nuclei observed in the STAR ZDC triggers. The lowest order QED
result for the experimental acceptance is nearly two standard deviations larger
than the STAR data. A corresponding higher order QED calculation is consistent
with the data.


title: Degree Bounds for Gr\"obner Bases in Algebras of Solvable Type

abstract:
  We establish doubly-exponential degree bounds for Gr\"obner bases in certain
algebras of solvable type over a field (as introduced by Kandri-Rody and
Weispfenning). The class of algebras considered here includes commutative
polynomial rings, Weyl algebras, and universal enveloping algebras of
finite-dimensional Lie algebras. For the computation of these bounds, we adapt
a method due to Dub\'e based on a generalization of Stanley decompositions. Our
bounds yield doubly-exponential degree bounds for ideal membership and
syzygies, generalizing the classical results of Hermann and Seidenberg (in the
commutative case) and Grigoriev (in the case of Weyl algebras).


title:
Small Structures via Thermal Instability of Partially Ionized Plasma. I.
  Condensation Mode

abstract:
  (Shortened) Thermal instability of partially ionized plasma is investigated
by linear perturbation analysis. According to the previous studies under the
one fluid approach, the thermal instability is suppressed due to the magnetic
pressure. However, the previous studies did not precisely consider the effect
of the ion-neutral friction, since they did not treat the flow as two fluid
which is composed of ions and neutrals. Then, we revisit the effect of the
ion-neutral friction of the two fluid to the growth of the thermal instability.
According to our study, (1) The instability which is characterized by the mean
molecular weight of neutrals is suppressed via the ion-neutral friction only
when the magnetic field and the friction are sufficiently strong. The
suppression owing to the friction occurs even along the field line. If the
magnetic field and the friction are not so strong, the instability is not
stabilized. (2) The effect of the friction and the magnetic field is mainly
reduction of the growth rate of the thermal instability of weakly ionized
plasma. (3) The effect of friction does not affect the critical wavelength
lambdaF for the thermal instability. This yields that lambdaF of the weakly
ionized plasma is not enlarged even when the magnetic field exists. We insist
that the thermal instability of the weakly ionized plasma in the magnetic field
can grow up even at the small length scale where the instability under the
assumption of the one fluid plasma can not grow owing to the stabilization by
the magnetic field. (4) The wavelength of the maximum growth rate of the
instability shifts shortward according to the decrement of the growth rate,
because the friction is effective at rather larger scale. Therefore, smaller
structures are expected to appear than those without the ion-neutral friction.


title: Physics at a future Neutrino Factory and super-beam facility

abstract:
  The conclusions of the Physics Working Group of the international scoping
study of a future Neutrino Factory and super-beam facility (the ISS) are
presented. The ISS was carried by the international community between NuFact05,
(the 7th International Workshop on Neutrino Factories and Superbeams,
Laboratori Nazionali di Frascati, Rome, June 21-26, 2005) and NuFact06 (Ivine,
California, 24{30 August 2006). The physics case for an extensive experimental
programme to understand the properties of the neutrino is presented and the
role of high-precision measurements of neutrino oscillations within this
programme is discussed in detail. The performance of second generation
super-beam experiments, beta-beam facilities, and the Neutrino Factory are
evaluated and a quantitative comparison of the discovery potential of the three
classes of facility is presented. High-precision studies of the properties of
the muon are complementary to the study of neutrino oscillations. The Neutrino
Factory has the potential to provide extremely intense muon beams and the
physics potential of such beams is discussed in the final section of the
report.


title: A New Algorithm in Geometry of Numbers

abstract:
  A lattice Delaunay polytope P is called perfect if its Delaunay sphere is the
only ellipsoid circumscribed about P. We present a new algorithm for finding
perfect Delaunay polytopes. Our method overcomes the major shortcomings of the
previously used method. We have implemented and used our algorithm for finding
perfect Delaunay polytopes in dimensions 6, 7, 8. Our findings lead to a new
conjecture that sheds light on the structure of lattice Delaunay tilings.


title: Detection of quantum light in the presence of noise

abstract:
  Detection of quantum light in the presence of dark counts and background
radiation noise is considered. The corresponding positive operator-valued
measure is obtained and photocounts statistics of quantum light in the presence
of noise is studied.


title: Titan's rotation: A 3-dimensional theory

abstract:
  We study the forced rotation of Titan seen as a rigid body at the equilibrium
Cassini state, involving the spin-orbit synchronization. We used both the
analytical and the numerical ways. We analytically determined the equilibrium
positions and the frequencies of the 3 free librations around it, while a
numerical integration associated to frequency analysis gave us a more
synthetic, complete theory, where the free solution split from the forced one.
We find a mean obliquity of 2.2 arcmin and the fundamental frequencies of the
free librations of about 2.0977, 167.4883, and 306.3360 years. Moreover, we
bring out the main role played by Titan's inclination on its rotation, and we
suspect a likely resonance involving Titan's wobble.


title:
A Symbolic Finite-state approach for Automated Proving of Theorems in
  Combinatorial Game Theory

abstract:
  We develop a finite-state automata approach, implemented in a Maple package
{\tt ToadsAndFrogs} available from our websites, for conjecturing, and then
rigorously proving, values for large families of positions in Richard Guy's
combinatorial game ``Toads and Frogs''. In particular, we prove a conjecture of
Jeff Erickson.


title: On descent theory and main conjectures in non-commutative Iwasawa theory

abstract:
  We prove a `Weierstrass Preparation Theorem' and develop an explicit descent
formalism in the context of Whitehead groups of non-commutative Iwasawa
algebras. We use these results to describe the precise connection between the
main conjecture of non-commutative Iwasawa theory (in the sense of Coates,
Fukaya, Kato, Sujatha and Venjakob) and the equivariant Tamagawa number
conjecture. The latter result is both a converse to a theorem of Fukaya and
Kato and also provides an important means of deriving explicit consequences of
the main conjecture.


title: Different canonical formulations of Einstein's theory of gravity

abstract:
  We describe the four most famous versions of the classical canonical
formalism in the Einstein theory of gravity: the Arnovitt-Deser-Misner
formalism, the Faddeev-Popov formalism, the tetrad formalism in the usual form,
and the tetrad formalism in the form best suited for constructing the loop
theory of gravity, which is now being developed. We present the canonical
transformations relating these formalisms. The paper is written mainly for
pedagogical purposes.


title: Cosmogenic neutrinos and quasi-stable supersymmetric particle production

abstract:
  We study the signal for the detection of quasi-stable supersymmetric
particles produced in interactions of cosmogenic neutrinos. We consider energy
loss of high energy staus due to photonuclear and weak interactions. We show
that there are optimal nadir angles for which the stau signal is a factor of
several hundred larager than muons. We discuss how one could potentially
eliminate the muon background by considering the energy loss of muons in the
detector. We also show results for the showers produced by weak interactions of
staus that reach the detector.


title: The MSSM Higgs sector and B-Bbar mixing for large tan(beta)

abstract:
  A systematic analysis of Higgs-mediated contributions to the Bd and Bs mass
differences is presented in the MSSM with large values of tan(beta). In
particular, supersymmetric corrections to Higgs self-interactions are seen to
modify the correlation between Delta Mq and BR(Bq --> mu+ mu-) for light
Higgses. The present experimental upper bound on BR(Bs --> mu+ mu-) is
nevertheless still sufficient to exclude noticeable Higgs-mediated effects on
the mass differences in most of the parameter space.


title: SMA High Angular Resolution Imaging of the Lensed Quasar APM08279+5255

abstract:
  We present Submillimeter Array observations of the z=3.91 gravitationally
lensed broad absorption line quasar APM08279+5255 which spatially resolve the
1.0mm (0.2mm rest-frame) dust continuum emission. At 0.4" resolution, the
emission is separated into two components, a stronger, extended one to the
northeast (46+/-5mJy) and a weaker, compact one to the southwest (15+/-2mJy).
We have carried out simulations of the gravitational lensing effect responsible
for the two submm components in order to constrain the intrinsic size of the
submm continuum emission. Using an elliptical lens potential, the best fit
lensing model yields an intrinsic (projected) diameter of ~80pc, which is not
as compact as the optical/near-infrared (NIR) emission and agrees with previous
size estimates of the gas and dust emission in APM08279+5255. Based on our
estimate, we favor a scenario in which the 0.2mm (rest-frame) emission
originates from a warm dust component (T_d=150-220K) that is mainly heated by
the AGN rather than by a starburst (SB). The flux is boosted by a factor of ~90
in our model, consistent with recent estimates for APM08279+5255.


title:
Fixing the fixed-point system - Applying Dynamic Renormalization Group
  to systems with long-range interactions

abstract:
  In this paper a mode of using the Dynamic Renormalization Group (DRG) method
is suggested in order to cope with inconsistent results obtained when applying
it to a continuous family of one-dimensional nonlocal models. The key
observation is that the correct fixed-point dynamical system has to be
identified during the analysis in order to account for all the relevant terms
that are generated under renormalization. This is well established for static
problems, however poorly implemented in dynamical ones. An application of this
approach to a nonlocal extension of the Kardar-Parisi-Zhang equation resolves
certain problems in one-dimension. Namely, obviously problematic predictions
are eliminated and the existing exact analytic results are recovered.

categories: cond-mat.stat-mech cond-mat.dis-nn math-ph math.MP


title:
Thermodynamics of Protein Folding from Coarse-Grained Models'
  Perspectives

abstract:
  Folding and aggregation of proteins, the interaction between proteins and
membranes, as well as the adsorption of organic soft matter to inorganic solid
substrates belong to the most interesting challenges in understanding structure
and function of complex macromolecules. This is reasoned by the
interdisciplinary character of the associated questions ranging from the
molecular origin of the loss of biological functionality as, for example, in
Alzheimer's disease to the development of organic circuits for biosensory
applications. In this lecture, we focus on the analysis of mesoscopic models
for protein folding, aggregation, and hybrid systems of soft and solid
condensed matter. The simplicity of the coarse-grained models allows for a more
universal description of the notoriously difficult problem of protein folding.
In this approach, classifications of structure formation processes with respect
to the conformational pseudophases are possible. This is similar in aggregation
and adsorption processes, where the individual folding propensity is influenced
by external forces. The main problem in studies of conformational transitions
is that the sequences of amino acids proteins are built up of are necessarily
of finite length and, therefore, a thermodynamic limit does not exist. Thus,
structural transitions are not phase transitions in the strict thermodynamic
sense and the analysis of pseudouniversal aspects is intricate, as apparently
small-system effects accompany all conformational transitions and cannot be
neglected.


title: Outlook from SUSY07

abstract:
  Make-or-break time is near for the Higgs boson and supersymmetry. The LHC
will soon put to the sword many theoretical ideas, and define the future for
collider physics.


title:
Freezing and Collapse of Flexible Polymers on Regular Lattices in Three
  Dimensions

abstract:
  We analyze the crystallization and collapse transition of a simple model for
flexible polymer chains on simple cubic and face-centered cubic lattices by
means of sophisticated chain-growth methods. In contrast to bond-fluctuation
polymer models in certain parameter ranges, where these two conformational
transitions were found to merge in the thermodynamic limit, we conclude from
our results that the two transitions remain well-separated in the limit of
infinite chain lengths. The reason for this qualitatively distinct behavior is
presumably due to the ultrashort attractive interaction range in the lattice
models considered here.


title: A Note on Graviton Amplitudes for New Twistor String Theories

abstract:
  A new class of twistor string theories were recently constructed by
Abou-Zeid, Hull and Mason. The most interesting one of these theories has the
particle content of N=8 supergravity. Arguments are given for the vanishing of
the (+ - -)-helicity amplitude for gravitons which suggest that this theory
describes a chiral N=8 supergravity rather than Einstein supergravity.


title: Connecting Galaxy Disk and Extended Halo Gas Kinematics

abstract:
  We have explored the galaxy disk/extended halo gas kinematic relationship
using rotation curves (Keck/ESI) of ten intermediate redshift galaxies which
were selected by MgII halo gas absorption observed in quasar spectra. Previous
results of six edge-on galaxies, probed along their major axis, suggest that
observed halo gas velocities are consistent with extended disk-like halo
rotation at galactocentric distances of 25-72 kpc. Using our new sample, we
demonstrate that the gas velocities are by and large not consistent with being
directly coupled to the galaxy kinematics. Thus, mechanisms other than
co-rotation dynamics (i.e., gas inflow, feedback, galaxy-galaxy interactions,
etc.) must be invoked to account for the overall observed kinematics of the
halo gas. In order to better understand the dynamic interaction of the
galaxy/halo/cosmic web environment, we performed similar mock observations of
galaxies and gaseous halos in Lambda-CDM cosmological simulations. We discuss
an example case of a z=0.92 galaxy with various orientations probing halo gas
at a range of positions. The gas dynamics inferred using simulated quasar
absorption lines are consistent with observational data.


title: Non Extensivity in Meteor Showers

abstract:
  A meteor shower is a luminous phenomenon that takes place by the entry into
the Earths atmosphere of a cascade of particles coming from a stream
intersected by our planet in its orbit. Here we investigate the possibility of
a description of the mass distribution of meteoroids in meteor showers int
terms of a non extensive formulation, which could shed light and give some
insight into the origin of such particles.


title: Cosmological Backreaction from Perturbations

abstract:
  We reformulate the averaged Einstein equations in a form suitable for use
with Newtonian gauge linear perturbation theory and track the size of the
modifications to standard Robertson-Walker evolution on the largest scales as a
function of redshift for both Einstein de-Sitter and Lambda CDM cosmologies. In
both cases the effective energy density arising from linear perturbations is of
the order of 10^-5 the matter density, as would be expected, with an effective
equation of state w ~ -1/19. Employing a modified Halofit code to extend our
results to quasilinear scales, we find that, while larger, the deviations from
Robertson-Walker behaviour remain of the order of 10^-5.


title: On compositions of numbers and graphs

abstract:
  The main purpose of this note is to pose a couple of problems which are
easily formulated thought some seem to be not yet solved. These problems are of
general interest for discrete mathematics including a new twig of a bough of
theory of graphs i.e. a given graph compositions. The problems result from and
are served in the entourage of series of exercises with hints based
predominantly on the second reference and other related recent papers.


title:
Uncertainties of the antiproton flux from Dark Matter annihilation in
  comparison to the EGRET excess of diffuse gamma rays

abstract:
  The EGRET excess of diffuse Galactic gamma rays shows all the features
expected from dark matter annihilation (DMA): a spectral shape given by the
fragmentation of mono-energetic quarks, which is the same in all sky directions
and an intensity distribution of the excess expected from a standard dark
matter halo, predicted by the rotation curve. From the EGRET excess one can
predict the flux of antiprotons from DMA. However, how many antiprotons arrive
at the detector strongly depends on the propagation model. The conventional
isotropic propagation models trap the antiprotons in the Galaxy leading to a
local antiproton flux far above the observed flux. According to Bergstrom et.
al. this excludes the DMA interpretation of the EGRET excess. Here it is shown
that more realistic anisotropic propagation models, in which most antiprotons
escape by fast transport in the z-direction, are consistent with the B/C ratio,
the antiproton flux and the EGRET excess from DMA.


title: Black Holes in Supergravity: the non-BPS Branch

abstract:
  We construct extremal, spherically symmetric black hole solutions to 4D
supergravity with charge assignments that preclude BPS-saturation. In
particular, we determine the ground state energy as a function of charges and
moduli. We find that the mass of the non-BPS black hole remains that of a
marginal bound state of four basic constituents throughout the entire moduli
space and that there is always a non-zero gap above the BPS bound.


title: Inversion of perturbation series

abstract:
  We investigate the inversion of perturbation series and its resummation, and
prove that it is related to a recently developed parametric perturbation
theory. Results for some illustrative examples show that in some cases series
reversion may improve the accuracy of the results.


title:
A Near-Infrared Spectroscopic Study of the Accreting Magnetic White
  Dwarf SDSS J121209.31+013627.7 and its Substellar Companion

abstract:
  The nature of the excess near-infrared emission associated with the magnetic
white dwarf commonly known as SDSS 1212 is investigated primarily through
spectroscopy, and also via photometry. The inferred low mass secondary in this
system has been previously detected by the emission and variation of H$\alpha$,
and the $1-2.5$ $\mu$m spectral data presented here are consistent with the
presence of a late L or early T dwarf. The excess flux seen beyond 1.5 $\mu$m
in the phase-averaged spectrum is adequately modeled with an L8 dwarf
substellar companion and cyclotron emission in a 7 MG magnetic field. This
interesting system manifests several observational properties typical of
polars, and is most likely an old interacting binary with a magnetic white
dwarf and a substellar donor in an extended low state.


title:
Explorando Sistemas Hamiltonianos II: A Natureza de Pontos de Equilibrio
  Degenerados

abstract:
  Neste segundo artigo sobre sistemas Hamiltonianos, apresentamos o metodo da
explosao para a determinacao da natureza de pontos fixos (pontos de equilibrio
degenerados. Aplicamos o metodo a dois modelos hamiltonianos com um e dois
graus de liberdade, respectivamente. Primeiramente, analisamos um sistema
formado por um pendulo simples submetido a um torque externo constante T. Em
seguida, consideramos um sistema formado por um pendulo duplo com segmentos de
comprimentos e massas iguais, tambem submetidos a torques externos constantes e
nao nulos. A presenca de pontos de equilibrio degenerados nos casos dos
pendulos simples e duplo ocorre para certos valores dos torques externos.
  In this second article on Hamiltonian systems, we present the blow-up method
for the determination of the nature of degenerate fixed points (equilibrium
points). We apply the method to two hamiltonian models with one and two degrees
of freedom, respectively. Firstly we study a system formed by a simple pendulum
submitted to a constant external torque T. Then we consider a system formed by
a double pendulum of segments with equal lengths and masses, also submitted to
non-vanishing constant external torques. The presence of degenerate equilibrium
points in both cases of simple and double pendulums occurs for some values of
the external torques.


title:
Limits of Gaudin algebras, quantization of bending flows, Jucys--Murphy
  elements and Gelfand--Tsetlin bases

abstract:
  Gaudin algebras form a family of maximal commutative subalgebras in the
tensor product of $n$ copies of the universal enveloping algebra $U(\g)$ of a
semisimple Lie algebra $\g$. This family is parameterized by collections of
pairwise distinct complex numbers $z_1,...,z_n$. We obtain some new commutative
subalgebras in $U(\g)^{\otimes n}$ as limit cases of Gaudin subalgebras. These
commutative subalgebras turn to be related to the hamiltonians of bending flows
and to the Gelfand--Tsetlin bases. We use this to prove the simplicity of
spectrum in the Gaudin model for some new cases.


title:
Nonlinear polarisation and dissipative correspondence between low
  frequency fluid and gyrofluid equations

abstract:
  The correspondence between gyrofluid and low frequency fluid equations is
examined. The lowest order conservative effects in ExB advection, parallel
dynamics, and curvature match trivially. The principal concerns are
polarisation fluxes, and dissipative parallel viscosity and parallel heat
fluxes. The emergence of the polarisation heat flux in the fluid model and its
contribution to the energy theorem is reviewed. It is shown that gyroviscosity
and the polarisation fluxes are matched by the finite gyroradius corrections to
advection in the long wavelength limit, provided that the differences between
gyrocenter and particle representations is taken into account. The dissipative
parallel viscosity is matched by the residual thermal anisotropy in the
gyrofluid model in the collision dominated limit. The dissipative parallel heat
flux is matched by the gyrofluid parallel heat flux variables in the collision
dominated limit. Hence, the gyrofluid equations are a complete superset of the
low frequency fluid equations.


title:
Liquid crystal anchoring transitions on aligning substrates processed by
  plasma beam

abstract:
  We observe a sequence of the anchoring transitions in nematic liquid crystals
(NLC) sandwiched between the hydrophobic polyimide substrates treated with the
plasma beam. There is a pronounced continuous transition from homeotropic to
low tilted (nearly planar) alignment with the easy axis parallel to the
incidence plane of the plasma beam (the zenithal transition) that takes place
as the exposure dose increases. In NLC with positive dielectric anisotropy, a
further increase in the exposure dose results in in-plane reorientation of the
easy axis by 90 degrees (the azimuthal transition). This transition occurs
through the two-fold degenerated alignment characteristic for the second order
anchoring transitions. In contrast to critical behavior of anchoring, the
contact angle of NLC and water on the treated substrates monotonically declines
with the exposure dose. It follows that the surface concentration of
hydrophobic chains decreases continuously. The anchoring transitions under
consideration are qualitatively interpreted by using a simple phenomenological
model of competing easy axes which is studied by analyzing anchoring diagrams
of the generalized polar and non-polar anchoring models.


title:
Measurement of CP Asymmetries and Branching Fractions in a
  Time-Dependent Dalitz Analysis of B^0-->(rho pi)^0 and a Constraint on the
  Quark Mixing Angle phi_2

abstract:
  We present the results of a time-dependent Dalitz plot analysis of B0 --> pi+
pi- pi0 decays based on a 414/fb data sample that contains 449 x 10^6 BB pairs.
The data was collected on the Upsilon(4S) resonance with the Belle detector at
the KEKB asymmetric energy e+e- collider. Combining our analysis with
information on charged B decay modes, we perform a full Dalitz and isospin
analysis and obtain a constraint on the quark mixing angle phi_2, 68deg. <
phi_2 < 95deg. at the 68.3% confidence level for the phi_2 solution consistent
with the standard model (SM). A large SM-disfavored region also remains. The
branching fractions for the decay processes of B0 --> rho+-(770) pi-+ and B0
--> rho0(770) pi0 are measured to be (22.6 +- 1.1[stat.] +- 4.4 [syst.]) x
10^{-6} and (3.0 +- 0.5 [stat.] +- 0.7 [syst.]) x 10^{-6}, respectively. These
are the first branching fraction measurements of the process B0 --> rho(770)pi
with the lowest resonance rho(770) explicitly separated from the radial
excitations.


title: Node discovery problem for a social network

abstract:
  Methods to solve a node discovery problem for a social network are presented.
Covert nodes refer to the nodes which are not observable directly. They
transmit the influence and affect the resulting collaborative activities among
the persons in a social network, but do not appear in the surveillance logs
which record the participants of the collaborative activities. Discovering the
covert nodes is identifying the suspicious logs where the covert nodes would
appear if the covert nodes became overt. The performance of the methods is
demonstrated with a test dataset generated from computationally synthesized
networks and a real organization.


title: q-Bernoulli numbers and Stirling numbers(2)

abstract:
  In this paper we study q-Bernoulli numbers and polynomials related to
q-Stirling numbers. From thsese studying we investigate some interesting
q-stirling numbers' identities related to q-Bernoulli numbers.


title:
An ab initio full potential fully relativistic study of atomic carbon,
  nitrogen, and oxygen chemisorption on the (111) surface of delta-plutonium

abstract:
  Adsorption of carbon, nitrogen, and oxygen on the (111) surface of
delta-Plutonium has been studied within the framework of density functional
theory using the full-potential linear augmented plane wave plus local basis
(FP-LAPW+lo) method. All adatoms prefer to bind at the higher coordinated
hollow sites, with the chemisorption energies for C, N, and O being 6.539 eV,
6.714 eV, and 8.2 eV respectively. The work function and the surface Pu
magnetic moments respectively increased and decreased in all cases upon
chemisorption. The partial charges inside the muffin tins spheres, difference
charge density distributions, and the local density of states have been used to
analyze the Pu-adatom bond interactions.


title: Limits of log canonical thresholds

abstract:
  Let T_n denote the set of log canonical thresholds of pairs (X,Y), with X a
nonsingular variety of dimension n, and Y a nonempty closed subscheme of X.
Using non-standard methods, we show that every limit of a decreasing sequence
in T_n lies in T_{n-1}, proving in this setting a conjecture of Koll\'{a}r. We
also show that T_n is a closed subset in the set of real numbers; in
particular, every limit of log canonical thresholds on smooth varieties of
fixed dimension is a rational number. As a consequence of this property, we see
that in order to check Shokurov's ACC Conjecture for all T_n, it is enough to
show that 1 is not a point of accumulation from below of any T_n. In a
different direction, we interpret the ACC Conjecture as a semi-continuity
property for log canonical thresholds of formal power series.


title:
High power radially polarized light generated from photonic crystal
  segmented half-wave-plate

abstract:
  We have generated more than 100 watts of radial polarized beam from a Yb
fiber laser using a photonics crystal segmented half-wave-plate. We
demonstrated the high power handling capability of such a photonics crystal
segmented half-wave-plate and show that it is a promising external radial
polarization converter for high power Yb fiber laser used in laser cutting
industry.


title:
Entangling the optical frequency comb: simultaneous generation of
  multiple 2x2 and 2x3 continuous-variable cluster states in a single optical
  parametric oscillator

abstract:
  We report on our research effort to generate large-scale multipartite
optical-mode entanglement using as few physical resources as possible. We have
previously shown that cluster- and GHZ-type N-partite continuous-variable
entanglement can be obtained in an optical resonator that contains a suitably
designed second-order nonlinear optical medium, pumped by at most O(N^2)
fields. In this paper, we show that the frequency comb of such a resonator can
be entangled into an arbitrary number of independent 2x2 and 2x3
continuous-variable cluster states by a single optical parametric oscillator
pumped by just a few optical modes.


title: A note on the p-adic log-gamma functions

abstract:
  In this paper we prove that q-Euler numbers are occured in the coefficients
of some stirling type seies for p-adic analytic q-log gamma function


title:
First to Market is not Everything: an Analysis of Preferential
  Attachment with Fitness

abstract:
  In this paper, we provide a rigorous analysis of preferential attachment with
fitness, a random graph model introduced by Bianconi and Barabasi. Depending on
the shape of the fitness distribution, we observe three distinct phases: a
first-mover-advantage phase, a fit-get-richer phase and an innovation-pays-off
phase.


title: Electroweak and Top Physics at the Tevatron and Indirect Higgs Limits

abstract:
  We report a selection of the most recent CDF and D0 results on top quark and
W and Z boson properties, based on Tevatron Run 2 data. The large datasets of W
and Z bosons allow a very precise measurement of the W mass and detailed
studies of vector boson production and asymmetries. Associated production of
vector boson pairs has been observed and cross sections have been measured. The
top quark is being studied in great detail, and a precision of 1.1 % in the
measurement of its mass has been achieved. The precise knowledge of top and W
masses are constraining the allowed mass range of a standard model Higgs in an
unprecedented way.


title:
Josephson Current and Multiple Andreev Reflections in Graphene SNS
  Junctions

abstract:
  The Josephson Effect and Superconducting Proximity Effect were observed in
Superconductor -Graphene-Superconductor (SGS) Josephson junctions with
coherence lengths comparable to the distance between the superconducting leads.
By comparing the measured temperature and doping dependence of the supercurrent
and the proximity induced sub-gap features (multiple Andreev reflections) to
theoretical predictions we find that, contrary to expectations, the ballistic
transport model fails to describe the SGS junctions. In contrast, the diffusive
junction model yields close quantitative agreement with the results. This
conclusion is consistent with transport measurements in the normal state, which
yield mean free paths in the graphene link that are much shorter than the
junction length. We show that all devices fabricated on SiO2 substrates so far
(our own as well as those reported by other groups) fall in the diffusive
junction category.


title: A new multi-component CKP hierarchy

abstract:
  We construct a new multi-component CKP hierarchy based on the eigenfunction
symmetry reduction. It contains two types of CKP equation with self-consistent
sources which Lax representations are presented. Also it admits reductions to
$k$-constrained CKP hierarchy and to a (1+1)-dimensional soliton hierarchy with
self-consistent source, which include two types of Kaup-Kuperschmidt equation
with self-consistent sources and of bi-directional Kaup-Kuperschmidt equation
with self-consistent sources.


title: Axisymmetric toroidal modes of magnetized neutron stars

abstract:
  We calculate axisymmetric toroidal modes of magnetized neutron stars with a
solid crust. We assume the interior of the star is threaded by a poloidal
magnetic field that is continuous at the surface with the outside dipole field
whose strength $B_p$ at the magnetic pole is $B_p\sim 10^{16}$G. Since
separation of variables is not possible for oscillations of magnetized stars,
we employ finite series expansions of the perturbations using spherical
harmonic functions to represent the angular dependence of the oscillation
modes. For $B_p\sim 10^{16}$G, we find distinct mode sequences, in each of
which the oscillation frequency of the toroidal mode slowly increases as the
number of radial nodes of the eigenfunction increases. The frequency spectrum
of the toroidal modes for $B_p\sim 10^{16}$G is largely different from that of
the crustal toroidal modes of the non-magnetized model, although the frequency
ranges are overlapped each other. This suggests that an interpretation of the
observed QPOs based on the magnetic toroidal modes may be possible if the field
strength of the star is as strong as $B_p\sim 10^{16}$G.


title: Universal source coding over generalized complementary delivery networks

abstract:
  This paper deals with a universal coding problem for a certain kind of
multiterminal source coding network called a generalized complementary delivery
network. In this network, messages from multiple correlated sources are jointly
encoded, and each decoder has access to some of the messages to enable it to
reproduce the other messages. Both fixed-to-fixed length and fixed-to-variable
length lossless coding schemes are considered. Explicit constructions of
universal codes and the bounds of the error probabilities are clarified by
using methods of types and graph-theoretical analysis.


title: Inter-vehicle gap statistics on signal-controlled crossroads

abstract:
  We investigate a microscopical structure in a chain of cars waiting at a red
signal on signal-controlled crossroads. Presented is an one-dimensional
space-continuous thermodynamical model leading to an excellent agreement with
the data measured.Moreover, we demonstrate that an inter-vehicle spacing
distribution disclosed in relevant traffic data agrees with the thermal-balance
distribution of particles in the thermodynamical traffic gas (discussed in [1])
with a high inverse temperature (corresponding to a strong traffic congestion).
Therefore, as we affirm, such a system of stationary cars can be understood as
a specific state of the traffic sample operating inside a congested traffic
stream.


title:
Exact minimum and maximum of yield with a finite number of decoy light
  intensities

abstract:
  In this paper, for the decoy state method using a finite number of decoy
light intensities, we present an improved upper and lower bounds for the
asymptotic yield y_n for n-photon states. In particular if all the light
intensities are less than or equal to one, they are not only a lower or upper
bound, but in fact are the exact minimum or maximum.


title:
Exploring the High-Energy Cosmic Ray Spectrum with a Toy Model of Cosmic
  Ray Diffusion

abstract:
  We introduce a static toy model of the cosmic ray (CR) universe in which
cosmic ray propagation is taken to be diffusive and cosmic ray sources are
distributed randomly with a density the same as that of local L* galaxies, $5
\times 10^{-3}$ Mpc$^{-3}$. These sources "fire" at random times through the
history of the universe but with a set expectation time for the period between
bursts. Our toy model model captures much of the essential CR physics despite
its simplicity and, moreover, broadly reproduces CR phenomenology for
reasonable parameter values and without extreme fine-tuning. Using this model
we investigate -- and find tenable -- the idea that the Milky Way may itself be
a typical high-energy cosmic ray source. We also consider the possible
phenomenological implications of the magnetic CR horizon for the overall cosmic
ray spectrum observed at Earth. Finally, we show that anisotropy studies should
most profitably focus on cosmic rays detected at energies above the so-called
GZK cut-off, $\sim 6 \times 10^{19}$ eV.


title:
The Fifteen Theorem for Universal Hermitian Lattices over Imaginary
  Quadratic Fields

abstract:
  We will introduce a method to get all universal Hermitian lattices over
imaginary quadratic fields over $\mathbb{Q}(\sqrt{-m})$ for all m. For each
imaginary quadratic field $\mathbb{Q}(\sqrt{-m})$, we obtain a criterion on
universality of Hermitian lattices: if a Hermitian lattice L represents 1, 2,
3, 5, 6, 7, 10, 13,14 and 15, then L is universal. We call this the fifteen
theorem for universal Hermitian lattices. Note that the difference between
Conway-Schneeberger's fifteen theorem and ours is the number 13.


title: Nonminimal isotropic cosmological model with Yang-Mills and Higgs fields

abstract:
  We establish a nonminimal Einstein-Yang-Mills-Higgs model, which contains six
coupling parameters. First three parameters relate to the nonminimal coupling
of non-Abelian gauge field and gravity field, two parameters describe the
so-called derivative nonminimal coupling of scalar multiplet with gravity
field, and the sixth parameter introduces the standard coupling of scalar field
with Ricci scalar. The formulated six-parameter nonminimal
Einstein-Yang-Mills-Higgs model is applied to cosmology. We show that there
exists a unique exact cosmological solution of the de Sitter type for a special
choice of the coupling parameters. The nonminimally extended Yang-Mills and
Higgs equations are satisfied for arbitrary gauge and scalar fields, when the
coupling parameters are specifically related to the curvature constant of the
isotropic spacetime. Basing on this special exact solution we discuss the
problem of a hidden anisotropy of the Yang-Mills field, and give an explicit
example, when the nonminimal coupling effectively screens the anisotropy
induced by the Yang-Mills field and thus restores the isotropy of the model.


title: Dark Energy may link the numbers of Rees

abstract:
  There is increasing evidence that the universe is dominated by dark energy of
the type given by an invariant cosmological constant. Latest data also
indicates that fundamental interaction couplings and particle masses have
remained remarkably constant from the earliest epochs. It is natural to connect
these two steady state features of the evolving universe, suggesting a role for
the cosmic vacuum energy in fixing these interaction constants. Advances in
high precision cosmology have revealed that dark matter of an unknown type
constitutes about one-fourth of cosmic matter while baryons account for just
four percent. These various cosmic parameters are enumerated by the six numbers
of Rees. With the dark energy as a unifying link these


title: Tau polarization in SUSY cascade decays at LHC

abstract:
  We explore how the polarization of the tau leptons in the cascade decay
$\tilde{q}\to q\tilde\chi^0_2\to q\tau\tilde\tau\to q\tau\tau\tilde\chi^0_1$
can be exploited to study mixing properties of neutralinos and staus. We
present details of the analysis including experimental effects such as
transverse momentum cuts for the $\tau\to\pi\nu$ decay mode, and show that the
di-pion invariant mass distribution provides valuable information on their
properties.


title: Toeplitz Operators, K\"ahler Manifolds, and Line Bundles

abstract:
  This is a survey paper. We discuss Toeplitz operators in K\"ahler geometry,
with applications to geometric quantization, and review some recent
developments.


title:
Large scale dynamics of the Persistent Turning Walker model of fish
  behavior

abstract:
  This paper considers a new model of individual displacement, based on fish
motion, the so-called Persistent Turning Walker (PTW) model, which involves an
Ornstein-Uhlenbeck process on the curvature of the particle trajectory. The
goal is to show that its large time and space scale dynamics is of diffusive
type, and to provide an analytic expression of the diffusion coefficient. Two
methods are investigated. In the first one, we compute the large time
asymptotics of the variance of the individual stochastic trajectories. The
second method is based on a diffusion approximation of the kinetic formulation
of these stochastic trajectories. The kinetic model is a Fokker-Planck type
equation posed in an extended phase-space involving the curvature among the
kinetic variables. We show that both methods lead to the same value of the
diffusion constant. We present some numerical simulations to illustrate the
theoretical results.


title:
Age-structured Trait Substitution Sequence Process and Canonical
  Equation

abstract:
  We are interested in a stochastic model of trait and age-structured
population undergoing mutation and selection. We start with a continuous time,
discrete individual-centered population process. Taking the large population
and rare mutations limits under a well-chosen time-scale separation condition,
we obtain a jump process that generalizes the Trait Substitution Sequence
process describing Adaptive Dynamics for populations without age structure.
Under the additional assumption of small mutations, we derive an age-dependent
ordinary differential equation that extends the Canonical Equation. These
evolutionary approximations have never been introduced to our knowledge. They
are based on ecological phenomena represented by PDEs that generalize the
Gurtin-McCamy equation in Demography. Another particularity is that they
involve a fitness function, describing the probability of invasion of the
resident population by the mutant one, that can not always be computed
explicitly. Examples illustrate how adding an age-structure enrich the
modelling of structured population by including life history features such as
senescence. In the cases considered, we establish the evolutionary
approximations and study their long time behavior and the nature of their
evolutionary singularities when computation is tractable. Numerical procedures
and simulations are carried.


title: Binary normal regular Hermitian lattices over imaginary quadratic fields

abstract:
  We call a positive definite Hermitian lattice regular if it represents all
integers which can be represented locally by the lattice. We investigate binary
regular Hermitian lattices over imaginary quadratic fields
$\mathbb{Q}(\sqrt{-m})$ and provide a complete list of the (normal) Hermitian
lattices.


title: L'analyse de l'expertise du point de vue de l'ergonomie cognitive

abstract:
  This paper presents a review of methods for collecting and analysing data on
complex activities. Starting with methods developed for design, we examine the
possibility to transpose them to other complex activities, especially
activities referring to sensorial expertise. R\'esum\'e Ce texte pr\'esente une
revue de m\'ethodes pour recueillir et analyser des donn\'ees sur des
actvit\'es complexes. A partir de m\'ethodes d\'evelopp\'ees pour des
actvit\'es de conception, nous examinons la possibilit\'e de les transposer \`a
d'autres actvit\'es complexes, notamment des actvit\'es faisant \`a appel \`a
des expertises sensorielles.


title: Diagrammatic quantum field formalism for localized electrons

abstract:
  We introduce a diagrammatic quantum field formalism for the evaluation of
normalized expectation values of operators, and suitable for systems with
localized electrons. It is used to develop a convergent series expansion for
the energy in powers of overlap integrals of single-particle orbitals. This
method gives intuitive and practical rules for writing down the expansion to
arbitrary order of overlap, and can be applied to any spin configuration and to
any dimension. Its applicability for systems with well localized electrons has
been illustrated with examples, including the two-dimensional Wigner crystal
and spin-singlets in the low-density electron gas.


title:
Anisotropic inharmonic Higgs oscillator and related (MICZ-)Kepler-like
  systems

abstract:
  We propose the integrable (pseudo)spherical generalization of the
four-dimensional anisotropic oscillator with additional nonlinear potential.
Performing its Kustaanheimo-Stiefel transformation we then obtain the
pseudospherical generalization of the MICZ-Kepler system with linear and
$\cos\theta$ potential terms. We also present the generalization of the
parabolic coordinates, in which this system admits the separation of variables.
Finally, we get the spherical analog of the presented MICZ-Kepler-like system.


title: The entropy of keys derived from laser speckle

abstract:
  Laser speckle has been proposed in a number of papers as a high-entropy
source of unpredictable bits for use in security applications. Bit strings
derived from speckle can be used for a variety of security purposes such as
identification, authentication, anti-counterfeiting, secure key storage, random
number generation and tamper protection. The choice of laser speckle as a
source of random keys is quite natural, given the chaotic properties of
speckle. However, this same chaotic behaviour also causes reproducibility
problems. Cryptographic protocols require either zero noise or very low noise
in their inputs; hence the issue of error rates is critical to applications of
laser speckle in cryptography. Most of the literature uses an error reduction
method based on Gabor filtering. Though the method is successful, it has not
been thoroughly analysed.
  In this paper we present a statistical analysis of Gabor-filtered speckle
patterns. We introduce a model in which perturbations are described as random
phase changes in the source plane. Using this model we compute the second and
fourth order statistics of Gabor coefficients. We determine the mutual
information between perturbed and unperturbed Gabor coefficients and the bit
error rate in the derived bit string. The mutual information provides an
absolute upper bound on the number of secure bits that can be reproducibly
extracted from noisy measurements.


title:
Tracer density discontinuities in turbulent flows: simple model and
  scaling laws

abstract:
  Mixing in fully developed incompressible turbulent flows is known to lead to
a cascade of discontinuity fronts of passive scalar fields. A one-dimensional
(1D) variant of Baker's map is developed, capturing the main mechanism
responsible for the emergence of these discontinuities. For this 1D model,
expressions for the height-distribution function of the discontinuity fronts
and structure function scaling exponents $\zeta_p$ are derived [for Kolmogorov
turbulence, $\zeta_p=\frac 23\log_3(p+1)$]. These analytic findings are in a
good agreement with both our 1D simulations, and the results of earlier
numerical and experimental studies.


title: Computer-intensive rate estimation, diverging statistics and scanning

abstract:
  A general rate estimation method is proposed that is based on studying the
in-sample evolution of appropriately chosen diverging/converging statistics.
The proposed rate estimators are based on simple least squares arguments, and
are shown to be accurate in a very general setting without requiring the choice
of a tuning parameter. The notion of scanning is introduced with the purpose of
extracting useful subsamples of the data series; the proposed rate estimation
method is applied to different scans, and the resulting estimators are then
combined to improve accuracy. Applications to heavy tail index estimation as
well as to the problem of estimating the long memory parameter are discussed; a
small simulation study complements our theoretical results.


title: Struggles with Survey Weighting and Regression Modeling

abstract:
  The general principles of Bayesian data analysis imply that models for survey
responses should be constructed conditional on all variables that affect the
probability of inclusion and nonresponse, which are also the variables used in
survey weighting and clustering. However, such models can quickly become very
complicated, with potentially thousands of poststratification cells. It is then
a challenge to develop general families of multilevel probability models that
yield reasonable Bayesian inferences. We discuss in the context of several
ongoing public health and social surveys. This work is currently open-ended,
and we conclude with thoughts on how research could proceed to solve these
problems.


title: CANE: The Content Addressed Network Environment

abstract:
  The fragmented nature and asymmetry of local and remote file access and
network access, combined with the current lack of robust authenticity and
privacy, hamstrings the current internet. The collection of disjoint and often
ad-hoc technologies currently in use are at least partially responsible for the
magnitude and potency of the plagues besetting the information economy, of
which spam and email borne virii are canonical examples. The proposed
replacement for the internet, Internet Protocol Version 6 (IPv6), does little
to tackle these underlying issues, instead concentrating on addressing the
technical issues of a decade ago.
  This paper introduces CANE, a Content Addressed Network Environment, and
compares it against current internet and related technologies. Specifically,
CANE presents a simple computing environment in which location is abstracted
away in favour of identity, and trust is explicitly defined. Identity is
cryptographically verified and yet remains pervasively open in nature. It is
argued that this approach is capable of being generalised such that file
storage and network access can be unified and subsequently combined with human
interfaces to result in a Unified Theory of Access, which addresses many of the
significant problems besetting the internet community of the early 21st
century.


title:
Sub-threshold production of $\Sigma$(1385) baryons in Al+Al collisions
  at 1.9$A$ GeV

abstract:
  First measurement of sub-threshold $\Sigma$(1385) production is presented.
Experimental data are presented for Al+Al reactions at 1.9$A$ GeV measured with
the FOPI detector at SIS/GSI. The $\Sigma$(1385)/$\Lambda$ ratio is found to be
in good agreement with the transport and statistical model predictions. The
results allow for a better understanding of sub-threshold strangeness
production and strangeness exchange reaction which is the dominant process for
$K^-$ production below and close-to threshold.


title:
Transport and magnetic properties in YBaCo2O5.45: Focus on the
  high-temperature transition

abstract:
  The electronic transport properties and the magnetic susceptibility were
measured in detail in $YBaCo_2O_{5.45}$. Close to the so-called metal-insulator
transition, strong effects of resistance relaxation, a clear thermal hysteresis
and a sudden increase of the resistance noise are observed. This is likely due
to the first order character of the transition and to the underlying phases
coexistence. Despite these out of equilibrium features, a positive and linear
magneto-resistance is also observed, possibly linked to the heterogeneity of
the state. From a magnetic point of view, the paramagnetic to ordered magnetic
state transition is observed using non linear susceptibilty. This transition
shows the characteristics of a continuous transition, and time dependent
effects can be linked with the dynamics of magnetic domains in presence of
disorder. Thus, when focusing on the order of the transitions, the electronic
one and the magnetic one can not be directly associated.


abstract:
  Comment: Struggles with Survey Weighting and Regression Modeling
[arXiv:0710.5005]


title: EOS of dense matter and fast rotation of neutron stars

abstract:
  Recent observations of XTE J1739-285 suggest that it contains a neutron star
rotating at 1122 Hz. Such rotational frequency would be the first for which the
effects of rotation are significant. We study the consequences of very fast
rotating neutron stars for the potentially observable quantities as stellar
mass and pulsar period.


title: A precursor state to unconventional superconductivity in CeIrIn${_5}$

abstract:
  We present sensitive measurements of the Hall effect and magnetoresistance in
CeIrIn${_5}$ down to temperatures of 50 mK and magnetic fields up to 15 T. The
presence of a low temperature coherent Kondo state is established. Deviations
from Kohler's rule and a quadratic temperature dependence of the cotangent of
the Hall angle are reminiscent of properties observed in the high temperature
superconducting cuprates. The most striking observation pertains to the
presence of a \textit{precursor} state--characterized by a change in the Hall
mobility--that appears to precede the superconductivity in this material, in
similarity to the pseudogap in the cuprate high $T_c$ superconductors.


title: Comment: Struggles with Survey Weighting and Regression Modeling


title: On $k$-noncrossing partitions

abstract:
  In this paper we prove a duality between $k$-noncrossing partitions over
$[n]=\{1,...,n\}$ and $k$-noncrossing braids over $[n-1]$. This duality is
derived directly via (generalized) vacillating tableaux which are in
correspondence to tangled-diagrams \cite{Reidys:07vac}. We give a combinatorial
interpretation of the bijection in terms of the contraction of arcs of
tangled-diagrams. Furthermore it induces by restriction a bijection between
$k$-noncrossing, 2-regular partitions over $[n]$ and $k$-noncrossing braids
without isolated points over $[n-1]$. Since braids without isolated points
correspond to enhanced partitions this allows, using the results of
\cite{MIRXIN}, to enumerate 2-regular, 3-noncrossing partitions.