title: The Zero Age Main Sequence of WIMP burners

abstract:
  We modify a stellar structure code to estimate the effect upon the main
sequence of the accretion of weakly interacting dark matter onto stars and its
subsequent annihilation. The effect upon the stars depends upon whether the
energy generation rate from dark matter annihilation is large enough to shut
off the nuclear burning in the star. Main sequence WIMP burners look much like
protostars moving on the Hayashi track, although they are in principle
completely stable. We make some brief comments about where such stars could be
found, how they might be observed and more detailed simulations which are
currently in progress. Finally we comment on whether or not it is possible to
link the paradoxically young OB stars found at the galactic centre with WIMP
burners.


title: Seventy Years of the EPR Paradox

abstract:
  In spite of the fact that statistical predictions of quantum theory (QT) can
only be tested if large amount of data is available a claim has been made that
QT provides the most complete description of an individual physical system.
Einstein's opposition to this claim and the paradox he presented in the article
written together with Podolsky and Rosen in 1935 inspired generations of
physicists in their quest for better understanding of QT. Seventy years after
EPR article it is clear that without deep understanding of the character and
limitations of QT one may not hope to find a meaningful unified theory of all
physical interactions, manipulate qubits or construct a quantum computer. In
this paper we present shortly the EPR paper and the discussion which followed
it. By emphasizing the difference between quantum phenomena and hypothetical
invisible sub phenomena we show that paradoxes are only found if incorrect
models of sub phenomena are used. The violation of Bell and CHSH inequalities
demonstrate clearly that "an entangled pair of photons" resembles neither "a
pair of Bertlmann's socks" nor "a pair of fair and random dices". Finally we
rephrase the EPR question by asking whether QT provides the complete
description of experimental data.


title:
Simple derivation of the special theory of relativity without the speed
  of light axiom

abstract:
  We show a very simple yet rigorous derivation of the invariance of the
space-time interval (and hence the whole special relativity) just from the
isotropy, homogeneity and a principle of relativity, without the need of the
speed of light axiom. This article is intended as a textbook explanation of the
special relativity.


title:
From Solar and Stellar Flares to Coronal Heating: Theory and
  Observations of How Magnetic Reconnection Regulates Coronal Conditions

abstract:
  There is currently no explanation of why the corona has the temperature and
density it has. We present a model which explains how the dynamics of magnetic
reconnection regulates the conditions in the corona. A bifurcation in magnetic
reconnection at a critical state enforces an upper bound on the coronal
temperature for a given density. We present observational evidence from 107
flares in 37 sun-like stars that stellar coronae are near this critical state.
The model may be important to self-organized criticality models of the solar
corona.


title: Intra Cluster Globular Clusters around NGC 1399 in Fornax?

abstract:
  We investigate whether the globular clusters (GCs) in the recently published
sample of GCs in the Fornax cluster by Bergond and coworkers are indeed
intra-cluster objects. We combine the catalogue of radial velocity measurements
by Bergond et al. with our CTIO MOSAIC photometry in the Washington system and
analyse the relation of metal-poor and metal-rich GCs with their host galaxies.
The metal-rich GCs appear to be kinematically associated with their respective
host galaxies. The vast majority of the metal-poor GCs found in between the
galaxies of the Fornax cluster have velocities which are consistent with them
being members of the very extended NGC 1399 GC system. We find that when the
sample is restricted to the most accurate velocity measurements, the GC
velocity dispersion profile can be described with a mass model derived for the
NGC 1399 GC system within 80 kpc. We identify one ``vagrant'' GC whose radial
velocity suggests that it is not bound to any galaxy unless its orbit has a
very large apogalactic distance.


title: Duality, Vector advection and the Navier-Stokes equations

abstract:
  In this article we show that three dimensional vector advection equation is
self dual in certain sense defined below. As a consequence, we infer classical
result of Serrin of existence of strong solution of Navier-Stokes equation.
Also we deduce Feynman-Kac type formula for solution of the vector advection
equation and show that the formula is not unique i.e. there exist flows which
differ from standard flow along which vorticity is conserved.


title: The 't Hooft Model As A Hologram

abstract:
  We consider the 3d dual of 1+1 dimensional large-N_c QCD with quarks in the
fundamental representation, also known as the 't Hooft model. 't Hooft solved
this model by deriving a Schroedinger equation for the wavefunction of a parton
inside the meson. In the scale-invariant limit, we show how this equation is
related by a transform to the equation of motion for a scalar field in AdS_3.
We thus find an explicit map between the `parton-x' variable and the radial
coordinate of AdS_3. This direct map allows us to check the AdS/CFT
prescription from the 2d side. We describe various features of the dual in the
conformal limit and to the leading order in conformal symmetry breaking, and
make some comments on the 3d theory in the fully non-conformal regime.


title: On the two-photon decay width of the sigma meson

abstract:
  We shortly report on the two-photon decay width of the light $\sigma$-meson
interpreted as a quarkonium state. Results are given in dependence on the
$\sigma$-mass and the constituent mass of the light quark. The triangle
quark-loop diagram, responsible for the two-photon transition, is carefully
evaluated: a term in the transition amplitude, often omitted in literature,
results in destructive interference with the leading term. As a result we show
that the two-photon decay width of the $\sigma $ in the quarkonium picture is
less than 1 keV for the physical range of parameters.


title:
Coherent, multi-heterodyne spectroscopy using stabilized optical
  frequency combs

abstract:
  The broadband, coherent nature of narrow-linewidth fiber frequency combs is
exploited to measure the full complex spectrum of a molecular gas through
multi-heterodyne spectroscopy. We measure the absorption and phase shift
experienced by each of 155,000 individual frequency comb lines, spaced by 100
MHz and spanning from 1495 nm to 1620 nm, after passing through a hydrogen
cyanide gas. The measured phase spectrum agrees with Kramers-Kronig
transformation of the absorption spectrum. This technique can provide a full
complex spectrum rapidly, over wide bandwidths, and with hertz-level accuracy.


title: Spectra of graph neighborhoods and scattering

abstract:
  Let $(G_\epsilon)_{\epsilon>0}$ be a family of '$\epsilon$-thin' Riemannian
manifolds modeled on a finite metric graph $G$, for example, the
$\epsilon$-neighborhood of an embedding of $G$ in some Euclidean space with
straight edges. We study the asymptotic behavior of the spectrum of the
Laplace-Beltrami operator on $G_\epsilon$ as $\epsilon\to 0$, for various
boundary conditions. We obtain complete asymptotic expansions for the $k$th
eigenvalue and the eigenfunctions, uniformly for $k\leq C\epsilon^{-1}$, in
terms of scattering data on a non-compact limit space. We then use this to
determine the quantum graph which is to be regarded as the limit object, in a
spectral sense, of the family $(G_\epsilon)$.
  Our method is a direct construction of approximate eigenfunctions from the
scattering and graph data, and use of a priori estimates to show that all
eigenfunctions are obtained in this way.


title:
Two-component jet simulations: I. Topological stability of analytical
  MHD outflow solutions

abstract:
  Observations of collimated outflows in young stellar objects indicate that
several features of the jets can be understood by adopting the picture of a
two-component outflow, wherein a central stellar component around the jet axis
is surrounded by an extended disk-wind. The precise contribution of each
component may depend on the intrinsic physical properties of the YSO-disk
system as well as its evolutionary stage. In this context, the present article
starts a systematic investigation of two-component jet models via
time-dependent simulations of two prototypical and complementary analytical
solutions, each closely related to the properties of stellar-outflows and
disk-winds. These models describe a meridionally and a radially self-similar
exact solution of the steady-state, ideal hydromagnetic equations,
respectively. By using the PLUTO code to carry out the simulations, the study
focuses on the topological stability of each of the two analytical solutions,
which are successfully extended to all space by removing their singularities.
In addition, their behavior and robustness over several physical and numerical
modifications is extensively examined. It is found that radially self-similar
solutions (disk-winds) always reach a final steady-state while maintaining all
their well-defined properties. The different ways to replace the singular part
of the solution around the symmetry axis, being a first approximation towards a
two-component outflow, lead to the appearance of a shock at the super-fast
domain corresponding to the fast magnetosonic separatrix surface. Conversely,
the asymptotic configuration and the stability of meridionally self-similar
models (stellar-winds) is related to the heating processes at the base of the
wind.


title: Little Higgs, Non-standard Higgs, No Higgs and All That

abstract:
  We give a brief review of recent developments in non-supersymmetric models
for electroweak symmetry breaking, including little Higgs, composite Higgs and
Higgsless theories. The new ideas such as extra dimensions, AdS/CFT
correspondence, dimension-deconstruction, and collective symmetry breaking
provide us new tools to construct new models. They also allow some old ideas to
be revived and implemented in these new models.


title:
Numerical solution of the radial Dirac equation in pseudopotential
  construction

abstract:
  In the present work we study numerical solution of the radial Dirac equation
in a specific case - ab-initio pseudopotential generating process - which is
needed within the electronic structure calculations using a Density Functional
Theory (DFT) combined with a pseudopotential method. We give a brief
introduction to DFT, derive the radial Dirac and Schrodinger equations, show
how to solve them both for a given energy and as an eigenvalue problem using a
known asymptotic behavior of the solution. Next we compare the nonrelativistic
and relativistic eigenvalues for one electron atom. Finally we state a few
words about the computer implementation.


title: Desingularizations of some Weighted Projective Planes

abstract:
  In this paper we discuss the desingularization algorithm for a toric surface.
In particular, we construct an iterable method of determining the
Hirzebruch-Jung continued fraction decomposition. These results are then
applied to weighted projective planes with at least one tivial weight,
${\mathbb P}(1,m,n)$. The paper concludes with the development of a computer
program that computes this continued fraction decomposition.


title:
Creation of neutral fundamental particles in the Weyl-Dirac version of
  Wesson's IMT

abstract:
  Spherically symmetric entities filled with matter induced by the 5D Bulk may
be built in the empty 4D space-time. The substance of the entity, the latter
regarded as a fundamental particle, is characterized by the prematter equ. of
state P=-rho. the particle is coverede by a Schwarzschild-like envelope and
from the outside it is characterized by mass and radius. One regard these
entities as neutral fundamental particles being constituents of quarks and
leptons. The presented classical models are developed in the framwork of the
Weyl-Dirac version of Wesson's IMT.


title:
Input Impedance, Nanocircuit Loading, and Radiation Tuning of Optical
  Nanoantennas

abstract:
  Here we explore the radiation features of optical nanoantennas, analyzing the
concepts of input impedance, optical radiation resistance, impedance matching
and loading of plasmonic nanodipoles. We discuss how the concept of antenna
impedance may be applied to optical frequencies, and how its quantity may be
properly defined and evaluated. We exploit these concepts in optimization of
nanoantenna loading by optical nanocircuit elements, extending classic concepts
of radio-frequency antenna theory to the visible regime for the proper design
and matching of plasmonic nanoantennas.


title: Associated Production for the Standard Model Higgs at CDF

abstract:
  We report the latest result for the search for the standard model higgs
produced in association with a W and a Z boson at CDF. The results include
about 1 to 1.7 fb-1 of data collected by CDF in run II of the Tevatron. Novel
analysis techniques have been developed to enhance the sensitivity of these
searches.


title: Effective cone of $overline{M}_{0,n}$ for odd $n$

abstract:
  In this work, we compute the effective cone of the space of $n$ pointed genus
0 rational curves, $\bar{M}_{0,n}$ for odd $n$. We will, in fact, use the
equivalence of $\bar{M}_{0,n}$ and the space of (semi) stable configurations of
$n$ weighted points on $\mathbb{CP}^{1}$ with special weight $(1,..., 1)$ up to
symmetric group action.


title: Kaon Weak Matrix Elements in 2+1 flavor DWF QCD

abstract:
  $K \to \pi$ and $K \to 0$ weak matrix elements of $\Delta S = 1$ operators
have been measured in 2+1 flavor domain wall fermion (DWF) QCD on (3 fm)$^3$
lattices with $a^{-1} = 1.73(3)$ GeV. As is well known, using these matrix
elements and chiral perturbation theory allows a determination of the $K \to
\pi \pi$ matrix elements that enter in the quantitative value for the $\Delta I
= 1/2$ rule and $\epsilon^\prime/\epsilon$. Two light dynamical sea quark
masses have been used, along with six valence quark masses, with the lightest
valence quark mass $\approx 1/10$ the physical strange quark mass. We report
our results for lattice matrix elements in the $SU(3)_L \times SU(3)_R$ (27,1),
(8,1), and (8,8) representations, paying particular attention to the
statistical errors achieved after measurements on 75 configurations. We also
report on our calculation of the non-perturbative renormalization coefficients
for these $\Delta S=1$ weak operators, using the Rome-Southampton method.


title: Modified gravity and the origin of inertia

abstract:
  Modified gravity theory is known to violate Birkhoff's theorem. We explore a
key consequence of this violation, the effect of distant matter in the Universe
on the motion of test particles. We find that when a particle is accelerated, a
force is experienced that is proportional to the particle's mass and
acceleration and acts in the direction opposite to that of the acceleration. We
identify this force with inertia. At very low accelerations, our inertial law
deviates slightly from that of Newton, yielding a testable prediction that may
be verified with relatively simple experiments. Our conclusions apply to all
gravity theories that reduce to a Yukawa-like force in the weak field
approximation.


title:
A new level of photometric precision: WIRE observations of eclipsing
  binary stars

abstract:
  The WIRE satellite was launched in March 1999 and was the first space mission
to do asteroseismology from space on a large number of stars. WIRE has produced
very high-precision photometry of a few hundred bright stars (V<6) with
temporal coverage of several weeks, including K giants, solar-like stars, delta
Scuti stars, and beta Cepheids. In the current work we will describe the status
of science done on seven detached eclipsing binary systems. Our results
emphasize some of the challenges and exciting results expected from coming
satellite missions like COROT and Kepler. Unfortunately, on 23 October 2006,
communication with WIRE failed after almost eight years in space. Because of
this sad news we will give a brief history of WIRE at the end of this paper.


title:
Coupled-cluster single-double calculations of the relativistic energy
  shifts in C IV, Na I, Mg II, Al III, Si IV, Ca II and Zn II

abstract:
  The relativistic coupled-cluster single-double method is used to calculate
the dependence of frequencies of strong $E1$-transitions in many monovalent
atoms and ions on the fine-structure constant $\alpha$. These transitions are
used in the search for manifestations of the variation of the fine-structure
constant in quasar absorption spectra. Results of the present calculations are
in good agreement with previous calculations but are more accurate.


title:
VHE gamma-rays from Westerlund 2 and implications for the inferred
  energetics

abstract:
  The H.E.S.S. collaboration recently reported the discovery of VHE gamma-ray
emission coincident with the young stellar cluster Westerlund 2. This system is
known to host a population of hot, massive stars, and, most particularly, the
WR binary WR20a. Particle acceleration to TeV energies in Westerlund 2 can be
accomplished in several alternative scenarios, therefore we only discuss
energetic constraints based on the total available kinetic energy in the
system, the actual mass loss rates of respective cluster members, and implied
gamma-ray production from processes such as inverse Compton scattering or
neutral pion decay. From the inferred gamma-ray luminosity of the order of
10^35 erg/s, implications for the efficiency of converting available kinetic
energy into non-thermal radiation associated with stellar winds in the
Westerlund 2 cluster are discussed under consideration of either the presence
or absence of wind clumping.


title: Moderate deviations for Poisson--Dirichlet distribution

abstract:
  The Poisson--Dirichlet distribution arises in many different areas. The
parameter $\theta$ in the distribution is the scaled mutation rate of a
population in the context of population genetics. The limiting case of $\theta$
approaching infinity is practically motivated and has led to new, interesting
mathematical structures. Laws of large numbers, fluctuation theorems and
large-deviation results have been established. In this paper,
moderate-deviation principles are established for the Poisson--Dirichlet
distribution, the GEM distribution, the homozygosity, and the Dirichlet process
when the parameter $\theta$ approaches infinity. These results, combined with
earlier work, not only provide a relatively complete picture of the asymptotic
behavior of the Poisson--Dirichlet distribution for large $\theta$, but also
lead to a better understanding of the large deviation problem associated with
the scaled homozygosity. They also reveal some new structures that are not
observed in existing large-deviation results.


title: Time Evolution of Disease Spread on Networks with Degree Heterogeneity

abstract:
  Two crucial elements facilitate the understanding and control of communicable
disease spread within a social setting. These components are, the underlying
contact structure among individuals that determines the pattern of disease
transmission; and the evolution of this pattern over time. Mathematical models
of infectious diseases, which are in principle analytically tractable, use two
general approaches to incorporate these elements. The first approach, generally
known as compartmental modeling, addresses the time evolution of disease spread
at the expense of simplifying the pattern of transmission. On the other hand,
the second approach uses network theory to incorporate detailed information
pertaining to the underlying contact structure among individuals. However,
while providing accurate estimates on the final size of outbreaks/epidemics,
this approach, in its current formalism, disregards the progression of time
during outbreaks. So far, the only alternative that enables the integration of
both aspects of disease spread simultaneously has been to abandon the
analytical approach and rely on computer simulations. We offer a new analytical
framework based on percolation theory, which incorporates both the complexity
of contact network structure and the time progression of disease spread.
Furthermore, we demonstrate that this framework is equally effective on finite-
and "infinite"-size networks. Application of this formalism is not limited to
disease spread; it can be equally applied to similar percolation phenomena on
networks in other areas in science and technology.


title: Modular model building

abstract:
  Mathematical models are increasingly used in both academia and the
pharmaceutical industry to understand how phenotypes emerge from systems of
molecular interactions. However, their current construction as monolithic sets
of equations presents a fundamental barrier to progress. Overcoming this
requires modularity, enabling sub-systems to be specified independently and
combined incrementally, and abstraction, enabling general properties to be
specified independently of specific instances. These in turn require models to
be represented as programs rather than as datatypes. Programmable modularity
and abstraction enables libraries of modules to be created for generic
biological processes, which can be instantiated and re-used repeatedly in
different contexts with different components. We have developed a computational
infrastructure to support this. We show here why these capabilities are needed,
what is required to implement them and what can be accomplished with them that
could not be done previously.


title:
A Simple Probabilistic Algorithm for Detecting Community Structure in
  Social Networks

abstract:
  In this paper, we propose a novel semi-parametric probabilistic model which
considers interactions between different communities and can provide more
information about the network topology besides correctly detecting communities.
By using an additional parameter, our model can not only detect community
structure but also detect pattern which is a generalization of common sense
network community structure. The prior parameter in our model reveals the
characteristics of patterns inside the network. Results on some widely known
data sets prove the efficiency of our model.


title: Quasidiagonality of crossed products

abstract:
  We prove that the crossed product A x G of a separable, unital, quasidiagonal
C*- algebra A by a discrete, countable, amenable, maximally almost periodic
group G is quasidiagonal, provided that the action is almost periodic.


title:
Growth, Structure and Properties of BiFeO3-BiCrO3 Films obtained by Dual
  Cross Beam PLD

abstract:
  The properties of epitaxial Bi2FeCrO6 thin films, recently synthesized by
pulsed laser deposition, have partially confirmed the theoretical predictions
(i.e. a magnetic moment of 2 muB per formula unit and a polarization of ~80
microC/cm2 at 0K). The existence of magnetic ordering at room temperature for
this material is an unexpected but very promising result that needs to be
further investigated. Since magnetism is assumed to arise from the exchange
interaction between the Fe and Cr cations, the magnetic behaviour is strongly
dependent on both their ordering and the distance between them. We present here
the successful synthesis of epitaxial Bi2FexCryO6 (BFCO x/y) films grown on
SrTiO3 substrates using dual crossed beam pulsed laser deposition. The crystal
structure of the films has different types of (111)-oriented superstructures
depending on the deposition conditions. The multiferroic character of BFCO
(x/y) films is proven by the presence of both ferroelectric and magnetic
hysteresis at room temperature. The oxidation state of Fe and Cr ions in the
films is shown to be 3+ only and the difference in macroscopic magnetization
with Fe/Cr ratio composition could only be due to ordering of the Cr3+ and Fe3+
cations therefore to the modification of the exchange interaction between them.


title: An entanglement measure for n-qubits

abstract:
  Recently, Coffman, Kundu, and Wootters introduced the residual entanglement
for three qubits to quantify the three-qubit entanglement in Phys. Rev. A 61,
052306 (2000). In Phys. Rev. A 65, 032304 (2007), we defined the residual
entanglement for $n$ qubits, whose values are between 0 and 1. In this paper,
we want to show that the residual entanglement for $n$ qubits is a natural
measure of entanglement by demonstrating the following properties. (1). It is
SL-invariant, especially LU-invariant. (2). It is an entanglement monotone.
(3). It is invariant under permutations of the qubits. (4). It vanishes or is
multiplicative for product states.


title: Some remarks on groupoids and small categories

abstract:
  This unpublished note contains some materials taken from my old study note on
groupoids and small categories. It contains a proof for the fact that any
groupoid is a group bundle over an equivalence relation. Moreover, the action
of a category $G$ on a category $H$ as well as the resulting semi-direct
product category $H\times_\alpha G$ will be defined (when either $G$ is a
groupoid or $H^{(0)} = G^{(0)}$). If both $G$ and $H$ are groupoids, then
$H\times_\alpha G$ is also a groupoid. The reason of producing this note is for
people who want to check some details in a recent work of Li.


title: Error Correction Capability of Column-Weight-Three LDPC Codes

abstract:
  In this paper, we investigate the error correction capability of
column-weight-three LDPC codes when decoded using the Gallager A algorithm. We
prove that the necessary condition for a code to correct $k \geq 5$ errors is
to avoid cycles of length up to $2k$ in its Tanner graph. As a consequence of
this result, we show that given any $\alpha>0, \exists N $ such that $\forall
n>N$, no code in the ensemble of column-weight-three codes can correct all
$\alpha n$ or fewer errors. We extend these results to the bit flipping
algorithm.


title: Shell-shocked diffusion model for the light curve of SN2006gy

abstract:
  We explore a simple model for the high luminosity of SN 2006gy involving
photon diffusion of shock-deposited thermal energy. The distinguishing property
of the model is that the large ``stellar'' radius of 160 AU required to prevent
adiabatic losses is not the true stellar radius, but rather, the radius of an
opaque, unbound circumstellar envelope, created when 10 Msun was ejected in the
decade before the supernova in an eruption analogous to that of eta Carinae.
The supernova light is produced primarily by diffusion of thermal energy
following the passage of the blast wave through this shell. This model differs
from traditional models of supernova debris interacting with external CSM in
that here the shell is optically thick and the escape of radiation is delayed.
We show that any model attempting to account for SN2006gy's huge luminosity
with radiation emitted by ongoing CSM interaction fails for the following basic
reason: the CSM density required to achieve the observed luminosity makes the
same circumstellar envelope opaque, forcing a thermal diffusion solution. In
our model, the weaker CSM interaction giving rise to SN2006gy's characteristic
Type IIn spectrum and soft X-rays is not linked to the power source of the
visual continuum; instead, it arises after the blast wave breaks free of the
opaque shell into the surrounding wind. While a simple diffusion model can
explain the gross properties of the early light curve of SN2006gy, it predicts
that the light curve must plummet rapidly at late-times, unless an additional
power source is present.


title: Axion Inflation and Gravity Waves in String Theory

abstract:
  The majority of models of inflation in string theory predict an absence of
measurable gravitational waves, r << 10^{-3}. The most promising proposals for
making string theoretic models that yield measurable tensor fluctuations
involve axion fields with slightly broken shift symmetry. We consider such
models in detail, with a particular focus on the N-flation scenario and on
axion valley/natural inflation models. We find that in Calabi-Yau threefold
compactifications with logarithmic Kahler potentials K it appears to be
difficult to meet the conditions required for axion inflation in the
supergravity regime. However, in supergravities with an (approximately)
quadratic shift-symmetric K, axion inflation may be viable. Such Kahler
potentials do arise in some string models, in specific limits of the moduli
space. We describe the most promising classes of models; more detailed study
will be required before one can conclude that working models exist.


title: Independent Signs of Lower Mass-Loss Rates for O-Type Stars

abstract:
  I discuss observational evidence -- independent of the direct spectral
diagnostics of stellar winds themselves -- suggesting that mass-loss rates for
O stars need to be revised downward by roughly a factor of three or more, in
line with recent observed mass-loss rates for clumped winds. These independent
constraints include the large observed mass-loss rates in LBV eruptions, the
large masses of evolved massive stars like LBVs and WNH stars, WR stars in
lower metallicity environments, observed rotation rates of massive stars at
different metallicity, supernovae that seem to defy expectations of high
mass-loss rates in stellar evolution, and other clues. I pay particular
attention to the role of feedback that would result from higher mass-loss
rates, driving the star to the Eddington limit too particular attention to the
role of feedback that would result from higher mass-loss rates, driving the
star to the Eddington limit too soon, and therefore making higher rates appear
highly implausible. Some of these arguments by themselves may have more than
one interpretation, but together they paint a consistent picture that steady
line-driven winds of O-type stars have lower mass-loss rates and are
significantly clumped.


title:
Possible Detection of a Pair Instability Supernova in the Modern
  Universe, and Implications for the First Stars

abstract:
  SN 2006gy radiated far more energy in visual light than any other supernova
so far, and potential explanations for its energy demands have implications for
galactic chemical evolution and the deaths of the first stars. It remained
bright for over 200 days, longer than any normal supernova, and it radiated
more than 1e51 ergs of luminous energy at visual wavelengths. I argue that this
Type IIn supernova was probably the explosion of an extremely massive star like
Eta Carinae that retained its hydrogen envelope when it exploded, having
suffered relatively little mass loss during its lifetime. That this occurred at
roughly Solar metallicity challenges current paradigms for mass loss in
massive-star evolution. I explore a few potential explanations for SN2006gy's
power source, involving either circumstellar interaction, or instead, the decay
of 56Ni. If SN 2006gy was powered by the conversion of shock energy into light,
then the conditions must be truly extraordinary and traditional interaction
models don't work. If SN 2006gy was powered by radioactive decay, then the
uncomfortably huge 56Ni mass requires that the star exploded as a pair
instability supernova. The mere possibility of this makes SN 2006gy
interesting, especially at this meeting, because it is the first good candidate
for a genuine pair instability supernova.


title:
SU(5) grand unification on a domain-wall brane from an E_6-invariant
  action

abstract:
  An SU(5) grand unification scheme for effective 3+1-dimensional fields
dynamically localised on a domain-wall brane is constructed. This is achieved
through the confluence of the clash-of-symmetries mechanism for symmetry
breaking through domain-wall formation, and the Dvali-Shifman gauge-boson
localisation idea. It requires an E_6 gauge-invariant action, yielding a
domain-wall solution that has E_6 broken to differently embedded SO(10) x U(1)
subgroups in the two bulk regions on opposite sides of the wall. On the wall
itself, the unbroken symmetry is the intersection of the two bulk subgroups,
and contains SU(5). A 4+1-dimensional fermion family in the 27 of E_6 gives
rise to localised left-handed zero-modes in the 5^* + 10 + 1 + 1 representation
of SU(5). The remaining ten fermion components of the 27 are delocalised exotic
states, not appearing in the effective 3+1-dimensional theory on the
domain-wall brane. The scheme is compatible with the type-2 Randall-Sundrum
mechanism for graviton localisation; the single extra dimension is infinite.


title:
Phase behavior and dynamics of a micelle-forming triblock copolymer
  system

abstract:
  Synperonic F-108 (generic name, 'pluronic') is a micelle forming triblock
copolymer of type ABA, where A is polyethylene oxide (PEO) and B is
polypropylene oxide (PPO). At high temperatures, the hydrophobicity of the PPO
chains increase, and the pluronic molecules, when dissolved in an aqueous
medium, self-associate into spherical micelles with dense PPO cores and
hydrated PEO coronas. At appropriately high concentrations, these micelles
arrange in a face centred cubic lattice to show inverse crystallization, with
the samples exhibiting high-temperature crystalline and low-temperature
fluidlike phases. By studying the evolution of the elastic and viscous moduli
as temperature is increased at a fixed rate, we construct the
concentration-temperature phase diagram of Synperonic F-108. For a certain
range of temperatures and at appropriate sample concentrations, we observe a
predominantly elastic response. Oscillatory strain amplitude sweep measurements
on these samples show pronounced peaks in the loss moduli, a typical feature of
soft solids. The soft solid-like nature of these materials is further
demonstrated by measuring their frequency dependent mechanical moduli. The
storage moduli are significantly larger than the loss moduli and are almost
independent of the applied angular frequency. Finally, we perform strain rate
frequency superposition (SRFS) experiments to measure the slow relaxation
dynamics of this soft solid.


title: Decay properties of charm and beauty open flavour mesons

abstract:
  The masses of $S$ and $P$ states, pseudoscalar and vector decay constants,
leptonic, semileptonic decay widths of charm (D) and beauty (B) open flavour
mesons have been computed in the framework of Coulomb and power potential of
the form $V(r)=-\frac{\alpha_c}{r}+A r^{\nu}$. The results are compared with
other theoretical as well as experimental results.


title: Numerical experimentation within GRworkbench

abstract:
  The software tool GRworkbench is an ongoing project in visual, numerical
General Relativity at The Australian National University. This year,
GRworkbench has been significantly extended to facilitate numerical
experimentation. The numerical differential geometric engine has been rewritten
using functional programming techniques, enabling fundamental concepts to be
directly represented as variables in the C++ code of GRworkbench. Sophisticated
general numerical methods have replaced simpler specialised algorithms. Various
tools for numerical experimentation have been implemented, allowing for the
simulation of complex physical situations.
  A recent claim, that the mass of the Milky Way can be measured using a small
interferometer located on the surface of the Earth, has been investigated, and
found to be an artifact of the approximations employed in the analysis. This
difficulty is symptomatic of the limitations of traditional pen-and-paper
analysis in General Relativity, which was the motivation behind the original
development of GRworkbench. The physical situation pertaining to the claim has
been modelled in a numerical experiment in GRworkbench, without the necessity
of making any simplifying assumptions, and an accurate estimate of the effect
has been obtained.


title: Spontaneous Emergence of Modularity in a Model of Evolving Individuals

abstract:
  We investigate the selective forces that promote the emergence of modularity
in nature. We demonstrate the spontaneous emergence of modularity in a
population of individuals that evolve in a changing environment. We show that
the level of modularity correlates with the rapidity and severity of
environmental change. The modularity arises as a synergistic response to the
noise in the environment in the presence of horizontal gene transfer. We
suggest that the hierarchical structure observed in the natural world may be a
broken symmetry state, which generically results from evolution in a changing
environment.


title:
Electronic Structures of CaAlSi with Different Stacking AlSi Layers by
  First-Principles Calculations

abstract:
  The full-potential linear augmented plane-wave calculations have been applied
to investigate the systematic change of electronic structures in CaAlSi due to
different stacking sequences of AlSi layers. The present ab-initio calculations
have revealed that the multistacking, buckling and 60 degrees rotation of AlSi
layer affect the electronic band structure in this system. In particular, such
a structural perturbation gives rise to the disconnected and cylindrical Fermi
surface along the M-L lines of the hexagonal Brillouin zone. This means that
multistacked CaAlSi with the buckling AlSi layers increases degree of
two-dimensional electronic characters, and it gives us qualitative
understanding for the quite different upper critical field anisotropy between
specimens with and without superstructure as reported previously.


title: Can one detect passage of small black hole through the Earth?

abstract:
  The energy losses of a small black hole passing through the Earth are
examined. In particular, we investigate the excitations in the frequency range
accessible to modern acoustic detectors. The main contribution to the effect is
given by the coherent sound radiation of the Cherenkov type.


title:
Utility-Based Wireless Resource Allocation for Variable Rate
  Transmission

abstract:
  For most wireless services with variable rate transmission, both average rate
and rate oscillation are important performance metrics. The traditional
performance criterion, utility of average transmission rate, boosts the average
rate but also results in high rate oscillations. We introduce a utility
function of instantaneous transmission rates. It is capable of facilitating the
resource allocation with flexible combinations of average rate and rate
oscillation. Based on the new utility, we consider the time and power
allocation in a time-shared wireless network. Two adaptation policies are
developed, namely, time sharing (TS) and joint time sharing and power control
(JTPC). An extension to quantized time sharing with limited channel feedback
(QTSL) for practical systems is also discussed. Simulation results show that by
controlling the concavity of the utility function, a tradeoff between the
average rate and rate oscillation can be easily made.


title: Five-dimensional Superfield Supergravity

abstract:
  We present a projective superspace formulation for matter-coupled simple
supergravity in five dimensions. Our starting point is the superspace
realization for the minimal supergravity multiplet proposed by Howe in 1981. We
introduce various off-shell supermultiplets (i.e. hypermultiplets, tensor and
vector multiplets) that describe matter fields coupled to supergravity. A
projective-invariant action principle is given, and specific dynamical systems
are constructed including supersymmetric nonlinear sigma-models. We believe
that this approach can be extended to other supergravity theories with eight
supercharges in $D\leq 6$ space-time dimensions, including the important case
of 4D N=2 supergravity.


title: Electron - nuclear recoil discrimination by pulse shape analysis

abstract:
  In the framework of the ``ULTIMA'' project, we use ultra cold superfluid 3He
bolometers for the direct detection of single particle events, aimed for a
future use as a dark matter detector. One parameter of the pulse shape observed
after such an event is the thermalization time constant. Until now it was
believed that this parameter only depends on geometrical factors and superfluid
3He properties, and that it is independent of the nature of the incident
particles. In this report we show new results which demonstrate that a
difference for muon- and neutron events, as well as events simulated by heater
pulses exist. The possibility to use this difference for event discrimination
in a future dark matter detector will be discussed.


title:
Measuring overlaps in mesoscopic spin glasses via conductance
  fluctuations

abstract:
  We consider the electonic transport in a mesoscopic metallic spin glasses. We
show that the distribution of overlaps between spin configurations can be
inferred from the reduction of the conductance fluctuations by the magnetic
impurities. Using this property, we propose new experimental protocols to probe
spin glasses directly through their overlaps.


title:
DPA on quasi delay insensitive asynchronous circuits: formalization and
  improvement

abstract:
  The purpose of this paper is to formally specify a flow devoted to the design
of Differential Power Analysis (DPA) resistant QDI asynchronous circuits. The
paper first proposes a formal modeling of the electrical signature of QDI
asynchronous circuits. The DPA is then applied to the formal model in order to
identify the source of leakage of this type of circuits. Finally, a complete
design flow is specified to minimize the information leakage. The relevancy and
efficiency of the approach is demonstrated using the design of an AES
crypto-processor.


title: Strangeness Content of the Nucleon in the \chiCQM_{config}

abstract:
  Several parameters characterizing the strangeness content of the nucleon have
been calculated in the chiral constituent quark model with configuration mixing
(\chiCQM_{config}) which is known to provide a satisfactory explanation of the
``proton spin problem'' and related issues. In particular, we have calculated
the strange spin polarization \Delta s, the strangeness contribution to the
weak axial vector couplings \Delta_8 etc., strangeness contribution to the
magnetic moments \mu(p)^s etc., the strange quark flavor fraction f_s, the
strangeness dependent quark ratios \frac{2 \bar s}{u+d} and \frac{2 \bar
s}{\bar u+\bar d} etc.. Our results show in general excellent agreement with
the recent experimental observations.


title: Vacuum densities for a thick brane in AdS spacetime

abstract:
  For a massive scalar field with general curvature coupling parameter we
evaluate Wightman function, vacuum expectation values of the field square and
the energy-momentum tensor induced by a $Z_{2}$-symmetric brane with finite
thickness located on $(D+1)$-dimensional AdS bulk. For the general case of
static plane symmetric interior structure the expectation values in the region
outside the brane are presented as the sum of free AdS and brane induced parts.
For a conformally coupled massless scalar the brane induced part in the vacuum
energy-momentum tensor vanishes. In the limit of strong gravitational fields
the brane induced parts are exponentially suppressed for points not too close
to the brane boundary. As an application of general results a special model is
considered in which the geometry inside the brane is a slice of the Minkowski
spacetime orbifolded along the direction perpendicular to the brane. For this
model the Wightman function, vacuum expectation values of the field square and
the energy-momentum tensor inside the brane are evaluated. It is shown that for
both minimally and conformally coupled scalar fields the interior vacuum forces
acting on the brane boundaries tend to decrease the brane thickness.


title: Conformal Invariance for Certain Models of the Bond-Triangular Type

abstract:
  Following the approach outlined in [18], convergence to SLE6 of the
Exploration Processes for the correlated bond-triangular type models studied in
[7] is established. This puts the said models in the same universality class as
the standard site percolation model on the triangular lattice [19]. The result
is proven for all domains with boundary (upper) Minkowski dimension less than
two. Moreover, the proof of convergence applies in the general context of
critical 2D percolation models, under the stipulation that Cardy's Formula can
be established.


title: Problems of Testology

abstract: Some problems of testology are discussed.


title: Spin Vortex in Magnon BEC of Superfluid 3He-B

abstract:
  The phenomenon of the spontaneous phase-coherent precession of magnetization
in superfluid 3He and the related effects of spin superfluidity are based on
the true Bose-Einstein condensation of magnons. Several different magnon BEC
states have been observed: homogeneously precessing domain (HPD); BEC
condensation in the spin-orbit potential trap (Q-balls); coherent precession
with fractional magnetization; and two modes of the coherent precession in
squeezed aerogel. The spin superfluidity effects, like spin Josephson
phenomena, spin current vortices, spin phase slippage, long distance
magnetization transport by spin supercurrents have been observed.


title: New non-abelian effects on D branes

abstract:
  We extend the Myers dielectric effect to configurations with angular
momentum. The resulting time-dependent N D0 brane bound states can be
interpreted as describing rotating fuzzy ellipsoids. A similar solution exists
also in the presence of a RR magnetic field, that we study in detail. We show
that, for any finite N, above a certain critical angular momentum is
energetically more favorable for the bound state system to dissociate into an
abelian configuration of N D0 branes moving independently. We have investigated
this problem in the low-energy expansion of the non-abelian D brane action for
generic N. In the case N=2 we find explicit solutions of the full non-abelian
Born-Infeld D brane dynamics, which remarkably have the same structure and
confirm the features of the low-energy approximation. We further study D string
configurations representing fuzzy funnels deformed by the magnetic field and by
the rotational motion.


title:
Spin up and phase fluctuations in the timing of the accreting
  millisecond pulsar XTE J1807-294

abstract:
  We performed a timing analysis of the 2003 outburst of the accreting X-ray
millisecond pulsar XTE J1807-294 observed by RXTE. Using recently refined
orbital parameters we report for the first time a precise estimate of the spin
frequency and of the spin frequency derivative. The phase delays of the pulse
profile show a strong erratic behavior superposed to what appears as a global
spin-up trend. The erratic behavior of the pulse phases is strongly related to
rapid variations of the light curve, making it very difficult to fit these
phase delays with a simple law. As in previous cases, we have therefore
analyzed separately the phase delays of the first harmonic and of the second
harmonic of the spin frequency, finding that the phases of the second harmonic
are far less affected by the erratic behavior. In the hypothesis that the
second harmonic pulse phase delays are a good tracer of the spin frequency
evolution we give for the first time a estimation of the spin frequency
derivative in this source. The source shows a clear spin-up of $\dot \nu =
2.5(7) \times 10^{-14}$ Hz sec$^{-1}$ (1 $\sigma$ confidence level). The
largest source of uncertainty in the value of the spin-up rate is given by the
uncertainties on the source position in the sky. We discuss this systematics on
the spin frequency and its derivative.


title: Comlexity of prime-dimensional sequences over a finite field

abstract:
  V.I. Arnold has recently defined the complexity of a sequence of $n$ zeros
and ones with the help of the operator of finite differences. In this paper we
describe the results obtained for almost most complicated sequences of elements
of a finite field, whose dimension $n$ is a prime number. We prove that with
$n\to \infty$ this property is inherent in almost all sequences, while the
values of multiplicative functions possess this property with any $n$ different
from the characteristic of the field. We also describe the prime values of the
parameter $n$ which make the logarithmic function almost most complicated. All
these sequences reveal a stronger complexity; its algebraic sense is quite
clear.


title: On Bost-Connes type systems for number fields

abstract:
  We give a complete description of the phase transition of the Bost-Connes
type systems for number fields recently introduced by
Connes-Marcolli-Ramachandran and Ha-Paugam. We also introduce a notion of
K-lattices and discuss an interpretation of these systems in terms of
1-dimensional K-lattices.


title: Inefficient quantum walks on networks: the role of the density of states

abstract:
  We show by general arguments that networks whose density of states contains
few highly degenerate eigenvalues result in inefficient performances of
continuous-time quantum walks (CTQW) over these networks, while systems whose
eigenvalues all have the same degeneracy lead to very efficient transport. We
exemplify our results by considering CTQW and, for comparison, its classical
counterpart, continuous-time random walks, over simple structures, whose
eigenvalues and eigenstates can be calculated analytically. Extensions to more
complicated, hyper-branched networks are discussed.


title: Measurement of Mass and Spin of Black Holes with QPOs

abstract:
  There are now four low mass X-ray binaries with black holes which show twin
resonant-like HFQPOs. Similar QPOs might have been found in Sgr A*. I review
the power spectral density distributions of the three X-ray flares and the six
NIR flares published for Sgr A* so far, in order to look for more similarities
than just the frequencies between the microquasar black holes and Sgr A*. The
three X-ray flares of Sgr A* are re-analysed in an identical way and white
noise probabilities from their power density distributions are given for the
periods reported around 1100 s. Progress of the resonant theory using the
anomalous orbital velocity effect is summarized.


title: Study of e+e- annihilation at low energies

abstract:
  The recent results of the CMD-2, SND, KLOE, and BABAR experiments on e+e-
annihilation into hadrons at low energies are reviewed.


title: On an extreme two-point distribution

abstract:
  A bound for functional $\Delta(F)=\sup_{x\in\mathbb R}|F(x)-\Phi(x)|$ is
obtained, which is uniform for all distribution functions $F$ of random
variables with zero mean-value and unity variance. Moreover, a two-point
distribution is found, for which this bound is reached.


title:
Disordered ground states in a quantum frustrated spin chain with side
  chains

abstract:
  We study a frustrated mixed spin chain with side chains, where the spin
species and the exchange interactions are spatially varied. A nonlinear sigma
model method is formulated for this model, and a phase diagram with two
disordered spin-gap phases is obtained for typical cases. Among them we examine
the case with a main chain consisting of an alternating array of spin-1 and
spin-1/2 sites and side chains each of a single spin-1/2 site in great detail.
Based on numerical, perturbational, and variational approaches, we propose a
singlet cluster solid picture for each phase, where the ground state is
expressed as a tensor product of local singlet states.


title:
Bayesian variable selection for high dimensional generalized linear
  models: convergence rates of the fitted densities

abstract:
  Bayesian variable selection has gained much empirical success recently in a
variety of applications when the number $K$ of explanatory variables
$(x_1,...,x_K)$ is possibly much larger than the sample size $n$. For
generalized linear models, if most of the $x_j$'s have very small effects on
the response $y$, we show that it is possible to use Bayesian variable
selection to reduce overfitting caused by the curse of dimensionality $K\gg n$.
In this approach a suitable prior can be used to choose a few out of the many
$x_j$'s to model $y$, so that the posterior will propose probability densities
$p$ that are ``often close'' to the true density $p^*$ in some sense. The
closeness can be described by a Hellinger distance between $p$ and $p^*$ that
scales at a power very close to $n^{-1/2}$, which is the ``finite-dimensional
rate'' corresponding to a low-dimensional situation. These findings extend some
recent work of Jiang [Technical Report 05-02 (2005) Dept. Statistics,
Northwestern Univ.] on consistency of Bayesian variable selection for binary
classification.


title: Bounded step functions and factorial ratio sequences

abstract:
  We study certain step functions whose nonnegativity is related to the
integrality of sequences of ratios of factorial products. In particular, we
obtain a lower bound for the mean square of such step functions which allows us
to give a restriction on when such a factorial ratio sequence can be integral.
Additionally, we note that this work has applications to the classification of
cyclic quotient singularities.


title: Boundary $C^*$-algebras for acylindrical groups

abstract:
  Let $\Delta$ be an infinite, locally finite tree with more than two ends. Let
$\Gamma<\aut(\Delta)$ be an acylindrical uniform lattice. Then the boundary
algebra $\cl A_\Gamma = C(\partial\Delta)\rtimes \Gamma$ is a simple
Cuntz-Krieger algebra whose K-theory is determined explicitly.


title:
The Frequency of Large Radius Hot and Very Hot Jupiters in omega
  Centauri

abstract:
  We present the results of a deep, wide-field search for transiting `Hot
Jupiter (HJ)' planets in the globular cluster omega Centauri. As a result of a
25-night observing run with the ANU 40-inch telescope at Siding Spring
Observatory, a total of 109,726 stellar time series composed of 787 independent
data points were produced with differential photometry in a 52x52' (0.75 deg^2)
field centered on the cluster core, but extending well beyond. Taking into
account the size of transit signals as a function of stellar radius, 45,406
stars have suitable photometric accuracy (<=0.045 mag to V=19.5) to search for
transits. Of this sample, 31,000 stars are expected to be main sequence cluster
members. All stars, both cluster and foreground, were subjected to a rigorous
search for transit signatures; none were found. Extensive Monte Carlo
simulations based on our actual data set allows us to determine the sensitivity
of our survey to planets with radii ~1.5R_Jup, and thus place statistical upper
limits on their occurrence frequency 'F'. Smaller planets are undetectable in
our data. At 95% confidence, the frequency of Very Hot Jupiters (VHJs) with
periods P satisfying 1d<P<3d can be no more than F_VHJ < 1/1040 in omega Cen.
For HJ and VHJ distributed uniformly over the orbital period range 1d<P<5d,
F_VHJ+HJ < 1/600. Our limits on large, short-period planets are comparable to
those recently reported for other Galactic fields, despite being derived with
less telescope time.


title:
Light hadron spectrum with 2+1 flavor dynamical $O(a)$-improved Wilson
  quarks

abstract:
  We present preliminary results for the light harden spectrum in $N_f=2+1$
lattice QCD obtained with the nonperturbatively $O(a)$-improved Wilson quark
action and the Iwasaki gauge action. Simulations are carried out at
$\beta=1.90$ on a $32^3 \times 64$ lattice using the PACS-CS computer. We
employ L\"uscher's domain-decomposed HMC algorithm to reduce the up-down quark
masses toward the physical value. The pseudoscalar meson masses range from 730
MeV down to 210 MeV. We compare the light harden spectrum extrapolated to the
physical point with the experimental values.


title: Supersolid phases in the extended boson hubbard model

abstract:
  We present a comprehensive numerical study on the ground state phase diagram
of the two-dimensional hardcore boson extended Hubbard model with nearest
($V_1$) and next nearest neighbor ($V_2$) repulsions. In addition to the
quantum solid and superfluid phases, we report the existence of striped
supersolid and three-quarter (quarter) filled supersolid at commensurate
density $\rho=0.75$ (0.25) due to the interplay of $V_1$ and $V_2$
interactions. The nature of three-quarter filled supersolid and the associated
quantum solid will be discussed. Quantum phase transition between the two
supersolids of different symmetries is observed and is clearly of first order.


title: Mathematical remarks on transcritical bifurcation in Hamiltonian systems

abstract:
  This article is meant as a mathematical appendix or comment on [BT]. We first
consider the notion of transcritical bifurcations of fixed points of general
area-preserving maps, and then adress some questions related to [BT] on
bifurcation in Poincar\'e maps of 2-dimensional Hamiltonian systems.
  [BT] M. Brack and K. Tanaka, arXiv:0705.0753


title: Critical Behavior of Disordered Systems with a Free Surface

abstract:
  The behavior of homogeneous and disordered systems with a free boundary is
described on the basis of group theory in the two-loop approximation directly
in three-dimensional space. The effect of the free boundary on the regime of
the bulk critical behavior is revealed. It is shown that the boundedness of the
system slightly affects the regime of the bulk critical behavior in the case of
the ordinary transition, whereas this effect is more noticeable in the case of
the special transition. Surface critical phenomena are described for
homogeneous and disordered systems, and the critical exponents are calculated
in the two-loop approximation. It is shown that the effect of impurities is
insignificant in the special phase transition, whereas it is more noticeable in
the ordinary phase transition. The derived critical exponents are compared with
the computer-simulation results.


title: Bifurcation of straight-line librations

abstract:
  We study a class of 2-dimensional Hamiltonian systems
$H(x,y,p_x,p_y)=\frac12(p_x^2+p_y^2) +V(x,y)$ in which the plane $x$=$p_x$=0 is
invariant under the Hamiltonian flow, so that straight-line librations along
the y axis exist, and we also consider perturbations $\delta H=\delta\cdot
F(x,y,p_x,p_y)$ that preserve these librations. We describe a procedure for the
analytical calculation of partial derivatives of the Poincar\'e map. These
partial derivatives can be used to predict the bifurcation behavior of the
libration, in particular to distinguish between transcritical and fork-like
bifurcations, as was mathematically investigated in [1] and numerically studied
in [2].
  [1] K. J\"anich, arXiv.org/abs/0710.3464 [2] M. Brack and K. Tanaka,
arXiv:0705.0753


title:
Application of chiral perturbation theory to 2+1 flavor lattice QCD with
  O(a)-improved Wilson quarks

abstract:
  We apply chiral perturbation theory to the pseudoscalar meson mass and decay
constant data obtained in the PACS-CS Project toward 2+1 flavor lattice QCD
simulations with the O(a)-improved Wilson quarks. We examine the existence of
chiral logarithms in the quark mass range from m_{ud}=47 MeV down to 6 MeV on a
(2.8 fm)^3 box with the lattice spacing a=0.09 fm. Several low energy constants
are determined. We also discuss the magnitude of finite size effects based on
chiral perturbation theory.


title: Meson correlators in the epsilon-regime of two-flavor lattice QCD

abstract:
  We calculate the meson correlators in the $\epsilon$-regime of two-flavor
QCD. On a $16^3\times 32$ lattice with $a\sim 0.11$ fm, the lattice simulations
are performed with the dynamical overlap fermions. We reduce the sea quark mass
down to $\sim$ 3 MeV and the valence quark masses are taken in the range 1-4
MeV. The meson correlators in various channels are compared with the
predictions of (partially quenched) chiral perturbation theory (ChPT).
Including the NLO order of the $\epsilon$-expansion, we extract the
leading-order low energy constants of ChPT, the pion decay constant $F$ and the
chiral condensate $\Sigma$, as $F=87.3(5.5)$ MeV and
$\Sigma^{\bar{\mathrm{MS}}}=[237.8(4.0){MeV}]^3$.


title: The physics case of DAFNE-2

abstract:
  We present the physics case of DAFNE-2, an $e^+e^-$ collider expected to
deliver 20-50 fb$^{-1}$ at the $\phi(1020)$ peak, and $\sim$ 5 fb$^{-1}$ in the
energy region between 1 and 2.5 GeV.


title:
Wahl's conjecture holds in odd characteristics for symplectic and
  orthogonal Grassmannians

abstract:
  It is shown that the proof by Mehta and Parameswaran of Wahl's conjecture for
Grassmannians in positive odd characteristics also works for symplectic and
orthogonal Grassmannians.


title: Dual Actions for Born-Infeld and Dp-Brane Theories

abstract:
  Dual actions with respect to U(1) gauge fields for Born-Infeld and $Dp$-brane
theories are reexamined. Taking into account an additional condition, i.e. a
corollary to the field equation of the auxiliary metric, one obtains an
alternative dual action that does not involve the infinite power series in the
auxiliary metric given by ref. \cite{s14}, but just picks out the first term
from the series formally. New effective interactions of the theories are
revealed. That is, the new dual action gives rise to an effective interaction
in terms of one interaction term rather than infinite terms of different
(higher) orders of interactions physically. However, the price paid for
eliminating the infinite power series is that the new action is not quadratic
but highly nonlinear in the Hodge dual of a $(p-1)$-form field strength. This
non-linearity is inevitable to the requirement the two dual actions are
equivalent.


title:
Memory effects in quantum information transmission across a Hamiltonian
  dephasing channel

abstract:
  We study a dephasing channel with memory, modelled by a multimode environment
of oscillators. Focusing on the case of two channel uses, we show that memory
effects can enhance the amount of coherent quantum information transmitted down
the channel. We also show the Kraus representation for two channel uses.
Finally, we propose a coding-decoding scheme that takes advantage of memory to
improve the fidelity of transmission.


title:
Modelling the effects of air pollution on health using Bayesian Dynamic
  Generalised Linear Models

abstract:
  The relationship between short-term exposure to air pollution and mortality
or morbidity has been the subject of much recent research, in which the
standard method of analysis uses Poisson linear or additive models. In this
paper we use a Bayesian dynamic generalised linear model (DGLM) to estimate
this relationship, which allows the standard linear or additive model to be
extended in two ways: (i) the long-term trend and temporal correlation present
in the health data can be modelled by an autoregressive process rather than a
smooth function of calendar time; (ii) the effects of air pollution are allowed
to evolve over time. The efficacy of these two extensions are investigated by
applying a series of dynamic and non-dynamic models to air pollution and
mortality data from Greater London. A Bayesian approach is taken throughout,
and a Markov chain monte carlo simulation algorithm is presented for inference.
An alternative likelihood based analysis is also presented, in order to allow a
direct comparison with the only previous analysis of air pollution and health
data using a DGLM.


title:
Numerical study of transport through a single impurity in a spinful
  Tomonaga-Luttinger liquid

abstract:
  The single impurity problem in a spinful Tomonaga-Luttinger liquid is studied
numerically using path-integral Monte Carlo methods. The advantage of our
approach is that the system allows for extensive analyses of charge and spin
conductance in the non-perturbative regime. By closely examining the behavior
of conductances at low temperatures, in the presence of a finite backward
scattering barrier due to the impurity, we identified four distinct phases
characterized by either perfect transmission or reflection of charge and spin
channels. Our phase diagram for an intermediate scattering strength is
consistent with the standard perturbative renormalization group (RG) analysis
in the limit of weak and strong backward scattering, in the sense that all our
phase boundaries interpolate the two limiting cases. Further investigations
show, however, that precise location and form of our phase boundaries are not
trivially explained by the standard RG analysis, e.g., some part of the phase
diagram looks much similar to the weak backscattering limit, whereas some other
part is clearly derived from the opposite limit. In order to give a more
intuitive interpretation of such behaviors, we also reconsidered our impurity
problem from the viewpoint of a quantum Brownian motion picture.


title: Can distributed delays perfectly stabilize dynamical networks?

abstract:
  Signal transmission delays tend to destabilize dynamical networks leading to
oscillation, but their dispersion contributes oppositely toward stabilization.
We analyze an integro-differential equation that describes the collective
dynamics of a neural network with distributed signal delays. With the gamma
distributed delays less dispersed than exponential distribution, the system
exhibits reentrant phenomena, in which the stability is once lost but then
recovered as the mean delay is increased. With delays dispersed more highly
than exponential, the system never destabilizes.


title:
Multi-particle entanglement and generalized N-particle teleportation
  using quantum statistical correlations

abstract:
  Construction of multi-particle entangled states and direct teleportation of
N-(spin 1/2) particles are important areas of quantum information processing. A
number of different schemes which have been presented already, address the
problem through controlled teleportation. In this article, a criterion based on
standard quantum statistical correlations employed in the many body virial
expansions is used to determine maximum entanglement for a N-particle state.
These states remain entangled through proper traces to states for a smaller
number of particles and can be generalized for arbitrary number of particles.
It is shown that they are quite useful in generalized, N-particle, direct
teleportation. The corresponding quantum gates are also indicated for
teleportation schemes from simple computational basis states.


title:
The poorly constrained cluster disruption time-scale in the Large
  Magellanic Cloud

abstract:
  We use Monte-Carlo simulations, combined with homogeneously determined age
and mass distributions based on multi-wavelength photometry, to constrain the
cluster formation history and the rate of bound cluster disruption in the Large
Magellanic Cloud (LMC) cluster system. We evolve synthetic star cluster systems
formed with a power-law initial cluster mass function (ICMF) of spectral index
$\alpha =-2$ assuming different cluster disruption time-scales. For each of
these disruption time-scales we derive the corresponding cluster formation rate
(CFR) required to reproduce the observed cluster age distribution. We then
compare, in a Poissonian $\chi^2$ sense, model mass distributions and model
two-dimensional distributions in log(mass) vs. log(age) space of the detected
surviving clusters to the observations. Because of the bright detection limit
($M_V^{\rm lim} \simeq -4.7$ mag) above which the observed cluster sample is
complete, one cannot constrain the characteristic disruption time-scale for a
$10^4$ M$_\odot$ cluster, $t_4^{\rm dis}$ (where the disruption time-scale
depends on cluster mass as $t_{\rm dis} = t_4^{\rm dis} (M_{\rm cl} / 10^4 {\rm
M}_\odot)^0.62$), to better than $t_4^{\rm dis} \ge 1$ Gyr. We conclude that
the CFR has increased from 0.3 clusters Myr$^{-1}$ 5 Gyr ago, to a present rate
of $(20-30)$ clusters Myr$^{-1}$. For older ages the derived CFR depends
sensitively on our assumption of the underlying CMF shape. If we assume a
universal Gaussian ICMF, then the CFR has increased steadily over a Hubble time
from $\sim 1$ cluster Gyr$^{-1}$ 15 Gyr ago to its present value. If the ICMF
has always been a power law with a slope close to $\alpha=-2$, the CFR exhibits
a minimum some 5 Gyr ago, which we tentatively identify with the well-known age
gap in the LMC's cluster age distribution.


title:
Nonparametric estimation of a point-spread function in multivariate
  problems

abstract:
  The removal of blur from a signal, in the presence of noise, is readily
accomplished if the blur can be described in precise mathematical terms.
However, there is growing interest in problems where the extent of blur is
known only approximately, for example in terms of a blur function which depends
on unknown parameters that must be computed from data. More challenging still
is the case where no parametric assumptions are made about the blur function.
There has been a limited amount of work in this setting, but it invariably
relies on iterative methods, sometimes under assumptions that are
mathematically convenient but physically unrealistic (e.g., that the operator
defined by the blur function has an integrable inverse). In this paper we
suggest a direct, noniterative approach to nonparametric, blind restoration of
a signal. Our method is based on a new, ridge-based method for deconvolution,
and requires only mild restrictions on the blur function. We show that the
convergence rate of the method is close to optimal, from some viewpoints, and
demonstrate its practical performance by applying it to real images.


title: Constrained Gauge Fields from Spontaneous Lorentz Violation

abstract:
  Spontaneous Lorentz violation realized through a nonlinear vector field
constraint of the type $A_{\mu}A^{\mu}=M^{2}$ ($M$ is the proposed scale for
Lorentz violation) is shown to generate massless vector Goldstone bosons,
gauging the starting global internal symmetries in arbitrary relativistically
invariant theories. The gauge invariance appears in essence as a necessary
condition for these bosons not to be superfluously restricted in degrees of
freedom, apart from the constraint due to which the true vacuum in a theory is
chosen by the Lorentz violation. In the Abelian symmetry case the only possible
theory proves to be QED with a massless vector Goldstone boson naturally
associated with the photon, while the non-Abelian symmetry case results in a
conventional Yang-Mills theory. These theories, both Abelian and non-Abelian,
look essentially nonlinear and contain particular Lorentz (and $CPT$) violating
couplings when expressed in terms of the pure Goldstone vector modes. However,
they do not lead to physical Lorentz violation due to the simultaneously
generated gauge invariance.


title: Penrose Limits vs String Expansions

abstract:
  We analyse the relation between two a priori quite different expansions of
the string equations of motion and constraints in a general curved background,
namely one based on the covariant Penrose-Fermi expansion of the metric
G_{\mu\nu} around a Penrose limit plane wave associated to a null geodesic
\gamma, and the other on the Riemann coordinate expansion in the exact metric
G_{\mu\nu} of the string embedding variables around the null geodesic \gamma.
Starting with the observation that there is a formal analogy between the exact
string equations in a plane wave and the first order string equations in a
general background, we show that this analogy becomes exact provided that one
chooses the background string configuration to be the null geodesic \gamma
itself. We then explore the higher-order correspondence between these two
expansions and find that for a general curved background they agree to all
orders provided that one works in Fermi coordinates and in the lightcone gauge.
Requiring moreover the conformal gauge restricts one to the usual class of
(Brinkmann) backgrounds admitting simultaneously the lightcone and the
conformal gauge, without further restrictions.


title:
Holomorphic Sobolev spaces, Hermite ans special Hermite semigroups and a
  Paley-Wiener theorem for the windowed Fourier transform

abstract:
  The images of Hermite and Laguerre Sobolev spaces under the Hermite and
special Hermite semigroups (respectively) are characterised. These are used to
characterise the Schwartz class of rapidly decreasing functions. The image of
the space of all tempered distributions is also considered and a Paley-Wiener
theorem for the windowed Fourier transform is proved.


title: A generalization of the Ginzburg-Landau theory to p-wave superconductors

abstract:
  We succeed to build up a straightforward theoretical model for spin-triplet
p-wave superconductors by introducing in Ginzburg-Landau theory a second order
parameter and a suitable interaction between the two mean fields.


title:
On Dimensional Analysis, Redundancy in set of fundamental quantities and
  Proposal of a New Set

abstract:
  Inclusion of redundant fundamental quantities in SI system has resulted in
lot of ambiguities and confusion in modern theories. The incompatibilities
between the existing theories can possibly be due to incorrect assumption of
fundamental quantities and existence of newer fundamental quantities. This
paper is an attempt to eliminate the redundancy in the SI system using random
mathematical mappings done through a computer program on SI system to New
System. Each mathematical mapping is studied manually. Out of 1000 random
mathematical mappings generated using a Computer Program, a mapping with three
fundamental quantities is found to describe a non-redundant and intuitive set
of Fundamental quantities. This paper also proposes the possible existence of a
new fundamental quantity. A significant attempt is made to understand the
advantages of new system over SI system. The relations between the set {Mass,
length, time, current, and temperature} and new set of three fundamental
quantities are calculated. The paper also describes the intuitive reasons
favoring the new fundamental set of quantities.


title: Hidden multiferroic order in graphene zigzag ribbons

abstract:
  The insulating magnetic phase in graphene zigzag ribbons, predicted both by
density functional and mean field Hubbard model calculations, is described
without additional approximations with a BCS wave function of two phase-locked
condensates of spin-polarized electron-hole pairs. The associated order
parameter is the spin dipole operator that features both magnetic and electric
order and accounts for the spin-resolved ferroelectricity of the system. Each
condensate is associated to a spin-dependent dipole and their relative phase
locking sets the total electric dipole and total magnetization equal to zero.


title: Symmetry of $osp(m|n)$ spin Calogero-Sutherland models

abstract:
  We introduce osp(m|n) spin Calogero-Sutherland models and find that the
models have the symmetry of osp(m|n) half-loop algebra or Yangian of osp(m|n)
if and only if the coupling constant of the model equals to 2/(m-n-4).


title:
Smooth crossing of $w_{\Lambda} = -1$ line in a single scalar field
  model

abstract:
  Smooth double crossing of the phantom divide line $w_{\Lambda}=-1$ has been
found possible with a single minimally coupled scalar field for the most simple
form of generalized k-essence cosmological model, in the presence of background
cold dark matter. Such crossing is a sufficiently late time transient phenomena
and does not have any pathological behaviour.


title:
Decoherence of nuclear spins due to direct dipole-dipole interactions
  probed by resistively detected nuclear magnetic resonance

abstract:
  We study decoherence of nuclear spins in a GaAs quantum well structure using
resistively detected nuclear magnetic resonance. The transverse decoherence
time T2 of 75As nuclei is estimated from Rabi-type coherent oscillations as
well as by using spin-echo techniques. By analyzing T2 obtained by decoupling
techniques, we extract the role of dipole-dipole interactions as sources of
decoherence in GaAs. Under the condition that the device is tilted in an
external magnetic field, we exhibit enhanced decoherence induced by the change
in strength of the direct dipole-dipole interactions between first
nearest-neighbor nuclei. The results agree well with simple numerical
calculations.


title: Microwave vortex dynamics in Tl-2212 thin films

abstract:
  We present measurements of the effective surface impedance changes due to a
static magnetic field, $\Delta Z(H,T)=\Delta R(H,T)+\rmi \Delta X(H,T)$, in a
Tl-2212 thin film with $T_c>$ 103 K, grown on a CeO$_2$ buffered sapphire
substrate. Measurements were performed through a dielectric resonator operating
at 47.7 GHz, for temperatures 60 K$\leq T<T_c$ and magnetic fields $\leq0.8$ T.
We observe exceptionally large field induced variations and pronounced
super-linear field dependencies in both $\Delta R(H)$ and $\Delta X(H)$ with
$\Delta X(H)>\Delta R(H)$ in almost the whole $(H,T)$ range explored. A careful
analysis of the data allows for an interpretation of these results as dominated
by vortex dynamics. In the intermediate-high field range we extract the main
vortex parameters by resorting to standard high frequency model and by taking
into proper account the creep contribution. The pinning constant shows a marked
decrease with the field which can be interpreted in terms of flux lines
softening associated to an incipient layer decoupling. Small vortex viscosity,
by an order of magnitude lower than in Y-123 are found. Some speculations about
these findings are provided.


title: Misssing experiments in relativity and gravity

abstract:
  The proposal is submitted for the measurement of the relativistic length
contraction using the nanoscopic dumbbell moving in LHC or ILC. Some paradoxes
concerning the length contraction and simultaneity are discussed. The dynamical
states of rods and strings accelerated by the gravitational field and
non-gravitational field are discussed. The realizaton of the acceleration of
the nanotube charged dumbbell in LHC, ILC and other accelerators is evidently
the prestige problem for the experts working in the accelerator physiocs.


title:
Minkowski space structure of the Higgs potential in 2HDM: II. Minima,
  symmetries, and topology

abstract:
  We continue to explore the consequences of the recently discovered Minkowski
space structure of the Higgs potential in the two-Higgs-doublet model. Here, we
focus on the vacuum properties. The search for extrema of the Higgs potential
is reformulated in terms of 3-quadrics in the 3+1-dimensional Minkowski space.
We prove that 2HDM cannot have more than two local minima in the orbit space
and that a twice-degenerate minimum can arise only via spontaneous violation of
a discrete symmetry of the Higgs potential. Investigating topology of the
3-quadrics, we give concise criteria for existence of non-contractible paths in
the Higgs orbit space. We also study explicit symmetries of the Higgs
potential/lagrangian and their spontaneous violation from a wider perspective
than usual.


title: A ridge-parameter approach to deconvolution

abstract:
  Kernel methods for deconvolution have attractive features, and prevail in the
literature. However, they have disadvantages, which include the fact that they
are usually suitable only for cases where the error distribution is infinitely
supported and its characteristic function does not ever vanish. Even in these
settings, optimal convergence rates are achieved by kernel estimators only when
the kernel is chosen to adapt to the unknown smoothness of the target
distribution. In this paper we suggest alternative ridge methods, not involving
kernels in any way. We show that ridge methods (a) do not require the
assumption that the error-distribution characteristic function is nonvanishing;
(b) adapt themselves remarkably well to the smoothness of the target density,
with the result that the degree of smoothness does not need to be directly
estimated; and (c) give optimal convergence rates in a broad range of settings.


title:
Global Mixed Periods and local Klyachko models for the general linear
  group

abstract:
  We show that every irreducible representation in the discrete automorphic
spectrum of GL(n) admits a non vanishing mixed (Whittaker-symplectic) period
integral. The analog local problem is a study of models first considered by
Klyachko over a finite field. Locally, we show that for a p-adic field F every
irreducible, unitary representation of GL(n,F) has a Klyachko model.


title: Small value probabilities via the branching tree heuristic

abstract:
  In the first part of this paper we give easy and intuitive proofs for the
small value probabilities of the martingale limit of a supercritical
Galton-Watson process in both the Schr\"oder and the B\"ottcher case. These
results are well-known, but the most cited proofs rely on generating function
arguments which are hard to transfer to other settings. In the second part we
show that the strategy underlying our proofs can be used in the quite different
context of self-intersections of stochastic processes. Solving a problem posed
by Wenbo Li, we find the small value probabilities for intersection local times
of several Brownian motions, as well as for self-intersection local times of a
single Brownian motion.


title:
Vector bundles on Hirzebruch surfaces whose twists by a non-ample line
  bundle have natural cohomology

abstract:
  Here we study vector bundles $E$ on the Hirzebruch surface $F_e$ such that
their twists by a spanned, but not ample, line bundle $M = \mathcal
{O}_{F_e}(h+ef)$ have natural cohomology, i.e. $h^0(F_e,E(tM)) >0$ implies
$h^1(F_e,E(tM)) = 0$.


title:
Novel features of the energy momentum tensor of a Casimir apparatus in a
  weak gravitational field

abstract:
  The influence of the gravity acceleration on the regularized energy-momentum
tensor of the quantized electromagnetic field between two plane parallel
conducting plates is derived. A perturbative expansion, to first order in the
constant acceleration parameter, of the Green functions involved and of the
energy-momentum tensor is derived by means of the covariant geodesic point
splitting procedure. The energy-momentum tensor is covariantly conserved and
satisfies the expected relation between gauge-breaking and ghost parts.


title: Use and misuse of ChPT in the heavy-light systems

abstract:
  We discuss the range of validity of ChPT when applied to the systems of
heavy-light mesons. Having in mind the recent experimental evidence according
to which the heavy-light scalar and axial states are closer to the ground
states than anticipated, we revisited the prediction for the chiral behavior of
the B-Bbar mixing amplitude and examined the impact of nearness of the positive
parity states. We conclude that the standard ChPT expressions with Nf=3 light
flavours are not useful in guiding the extrapolation of hadronic quantities
computed on the lattice. Instead those derived in HMChPT with Nf=2, i.e.,
including only the pion loops, are still adequate as long as they are applied
to the pions lighter than 350 MeV, or the quarks lighter than a third of the
physical strange quark mass.


title:
Applicability of Boussinesq approximation in a turbulent fluid with
  constant properties

abstract:
  The equations of motion describing buoyant fluids are often simplified using
a set of approximations proposed by J. Boussinesq one century ago. To resume,
they consist in assuming constant fluid properties, incompressibility and
conservation of calories during heat transport. Assuming fulfilment of the
first requirement (constant fluid properties), we derive a set of 4 criteria
for assessing the validity of the two other requirements in turbulent
Rayleigh-B\'enard convection. The first criterion $\alpha \Delta \ll 1 $ simply
results from the incompressibility condition in the thermal boundary layer
($\alpha$ and $\Delta$ are the thermal expansion coefficient and the
temperature difference driving the flow). The 3 other criteria are proportional
or quadratic with the density stratification or, equivalently with the
temperature difference resulting from the adiabatic gradient across the cell
$\Delta_{h}$. Numerical evaluations with air, water and cryogenic helium show
that most laboratory experiments are free from such Boussinesq violation as
long as the first criterion is fulfilled. In ultra high Rayleigh numbers
($Ra>10^{16}$) experiments in He, one of the stratification criteria, scaling
with $\alpha \Delta_{h}$, could be violated. This criterion garanties that
pressure fluctuations have a negligible influence both on the density variation
and on the heat transfer equation through compression/expansion cycles.
Extrapolation to higher $Ra$ suggests that strong violation of Boussinesq
approximation could occur in atmospheric convection.


title: B_s Mixing and B Hadron Lifetimes at CDF

abstract:
  We present the CDF results using 1.0 fb^{-1} of data on the mixing frequency
measurement in the B_s system and the lifetime measurements of several B
hadrons. We obtain \Delta m_s=17.77 +- 0.1 +- 0.07 ps^{-1} and
c\tau(\Lambda_b)=473.8 +- 23.1 +- 3.5 \mu m. The later one is more than 3 sigma
above the world average, but in reasonable agreement with HQE calculations.


title:
Ultraviolet observations of the X-ray photoionized wind of Cygnus X-1
  during X-ray soft/high state

abstract:
  (Shortened) Ultraviolet observations of the black hole X-ray binary Cygnus
X-1 were obtained using the STIS on HSTubble. We detect P Cygni line features
show strong, broad absorption components when the X-ray source is behind the
companion star and noticeably weaker absorption when the X-ray source is
between us and the companion star. We fit the P Cygni profiles using the SEI
method applied to a spherically symmetric stellar wind subject to X-ray
photoionization from the black hole. The Si IV doublet provides the most
reliable estimates of the parameters of the wind and X-ray illumination. The
velocity $v$ increases with radius $r$ according to
$v=v_\infty(1-r_\star/r)^\beta$, with$\beta\approx0.75$ and
$v_\infty\approx1420$ km s$^{-1}$.The microturbulent velocity was $\approx160$
km s$^{-1}$. Our fit implies a ratio of X-ray luminosity to wind mass-loss rate
of L$_{X,38}/\dot M_{-6} \approx 0.33$, measured at $\dot M_{-6}$ = 4.8. Our
models determine parameters that may be used to estimate the accretion rate
onto the black hole and independently predict the X-ray luminosity. Our
predicted L$_x$ matches that determined by contemporaneous RXTE ASM remarkably
well, but is a factor of 3 lower than the rate according to
Bondi-Hoyle-Littleton spherical wind accretion. We suggest that some of the
energy of accretion may go into powering a jet.


title: Heat Flow in Classical and Quantum Systems and Thermal Rectification

abstract:
  The understanding of the underlying dynamical mechanisms which determine the
macroscopic laws of heat conduction is a long standing task of non-equilibrium
statistical mechanics. A better understanding of the mechanism of heat
conduction may lead to potentially interesting applications based on the
possibility to control the heat flow. Indeed, different models of thermal
rectifiers has been recently proposed in which heat can flow preferentially in
one direction. Although these models are far away from a prototype realization,
the underlying mechanisms are of very general nature and, as such, are suitable
of improvement and may eventually lead to real applications. We briefly discuss
the problem of heat transport in classical and quantum systems and its relation
to the chaoticity of the dynamics. We then study the phenomenon of thermal
rectification and briefly discuss the different types of microscopic mechanisms
that lead to the rectification of heat flow.


title: Boundary-value problems in cosmological dynamics

abstract:
  The dynamics of cosmological gravitating system is governed by the Euler and
the Poisson equations. Tiny fluctuations near the big bang singularity are
amplified by gravitational instability into the observed structure today. Given
the current distribution of galaxies and assuming initial homogeneity,
dynamical reconstruction methods have been developed to derive the cosmic
density and velocity fields back in time. The reconstruction method described
here is based a least action principle formulation of the dynamics of
collisionless particle (representing galaxies). Two observational data sets
will be considered. The first is the distribution of galaxies which is assumed
to be an honest tracer of the mass density field of the dark matter. The second
set is measurements of the peculiar velocities (deviations from pure Hubble
flow) of galaxies. Given the first data set, the reconstruction method recovers
the associated velocity field which can then be compared with the second data
set. This comparison constrains the nature of the dark matter and the relation
between mass and light in the Universe.


title:
Using Synchronic and Diachronic Relations for Summarizing Multiple
  Documents Describing Evolving Events

abstract:
  In this paper we present a fresh look at the problem of summarizing evolving
events from multiple sources. After a discussion concerning the nature of
evolving events we introduce a distinction between linearly and non-linearly
evolving events. We present then a general methodology for the automatic
creation of summaries from evolving events. At its heart lie the notions of
Synchronic and Diachronic cross-document Relations (SDRs), whose aim is the
identification of similarities and differences between sources, from a
synchronical and diachronical perspective. SDRs do not connect documents or
textual elements found therein, but structures one might call messages.
Applying this methodology will yield a set of messages and relations, SDRs,
connecting them, that is a graph which we call grid. We will show how such a
grid can be considered as the starting point of a Natural Language Generation
System. The methodology is evaluated in two case-studies, one for linearly
evolving events (descriptions of football matches) and another one for
non-linearly evolving events (terrorist incidents involving hostages). In both
cases we evaluate the results produced by our computational systems.


title: Enhanced van der Waals interaction at interfaces

abstract:
  Using a recently obtained (general) formula for the interaction energy
between an excited and a ground-state atom (Sherkunov Y 2007 Phys. Rev. A 75
012705), we consider the interaction energy between two such atoms near the
interface between two media. We demonstrate that under the circumstances of the
resonant coupling of the excited atom to the surface polariton mode of a
vacuum-medium system the nonretarded atom*-atom interaction energy can be
enhanced by (several) orders of magnitude in comparison with the van der Waals
interaction energy of the two isolated atoms.


title: High-Mass X-ray Binaries and the Spiral Structure of the Host Galaxy

abstract:
  We investigate the manifestation of the spiral structure in the distribution
of high-mass X-ray binaries (HMXBs) over the host galaxy. We construct the
simple kinematic model. It shows that the HMXBs should be displaced relative to
the spiral structure observed in such traditional star formation rate
indicators as the Halpha and FIR emissions because of their finite lifetimes.
Using Chandra observations of M51, we have studied the distribution of X-ray
sources relative to the spiral arms of this galaxy observed in Halpha. Based on
K-band data and background source number counts, we have separated the
contributions from high-mass and low-mass X-ray binaries and active galactic
nuclei. In agreement with model predictions, the distribution of HMXBs is wider
than that of bright HII regions concentrated in the region of ongoing star
formation. However, the statistical significance of this result is low, as is
the significance of the concentration of the total population of X-ray sources
to the spiral arms. We also predict the distribution of HMXBs in our Galaxy in
Galactic longitude. The distribution depends on the mean HMXB age and can
differ significantly from the distributions of such young objects as
ultracompact HII regions.


title: Recent Studies in Superconductivity at Extreme Pressures

abstract:
  Studies of the effect of high pressure on superconductivity began in 1925
with the seminal work of Sizoo and Onnes on Sn to 0.03 GPa and have continued
up to the present day to pressures in the 200 - 300 GPa range. Such enormous
pressures cause profound changes in all condensed matter properties, including
superconductivity. In high pressure experiments metallic elements, Tc values
have been elevated to temperatures as high as 20 K for Y at 115 GPa and 25 K
for Ca at 160 GPa. These pressures are sufficient to turn many insulators into
metals and magnetics into superconductors. The changes will be particularly
dramatic when the pressure is sufficient to break up one or more atomic shells.
Recent results in superconductivity to Mbar pressures wll be discussed which
exemplify the progress made in this field over the past 82 years.


title:
Dynamics in One-Dimensional Spin Systems - Density-Matrix
  Renormalization Group Study

abstract:
  We study the one-dimensional $S=1/2$ Heisenberg model with a uniform and a
staggered magnetic fields, using the dynamical density-matrix renormalization
group (DDMRG) technique. The DDMRG enables us to investigate the dynamical
properties of chain with lengths up to a few hundreds, and the results are
numerically exact in the same sense as 'exact diagonalization' results are.
Thus, we can analyze the low-energy spectrum almost in the thermodynamic limit.
In this work, we calculate the dynamical spin structure factor and demonstrate
the performance of the DDMRG method applying the open-end boundary condition as
well as the periodic boundary condition.


title: Attractors in coherent systems of differential equations

abstract:
  Attractors of cooperative dynamical systems are particularly simple; for
example, a nontrivial periodic orbit cannot be an attractor. This paper
provides characterizations of attractors for the wider class of coherent
systems, defined by the property that no directed feedback loops are negative.
Several new results for cooperative systems are obtained in the process.


title: Wavelet sets without groups

abstract:
  Most of the examples of wavelet sets are for dilation sets which are groups.
We find a necessary and sufficient condition under which subspace wavelet sets
exist for dilation sets of the form $A B$, which are not necessarily groups. We
explain the construction by a few examples.


title:
Integral curves of noisy vector fields and statistical problems in
  diffusion tensor imaging: nonparametric kernel estimation and hypotheses
  testing

abstract:
  Let $v$ be a vector field in a bounded open set $G\subset {\mathbb {R}}^d$.
Suppose that $v$ is observed with a random noise at random points $X_i,
i=1,...,n,$ that are independent and uniformly distributed in $G.$ The problem
is to estimate the integral curve of the differential equation
\[\frac{dx(t)}{dt}=v(x(t)),\qquad t\geq 0,x(0)=x_0\in G,\] starting at a given
point $x(0)=x_0\in G$ and to develop statistical tests for the hypothesis that
the integral curve reaches a specified set $\Gamma\subset G.$ We develop an
estimation procedure based on a Nadaraya--Watson type kernel regression
estimator, show the asymptotic normality of the estimated integral curve and
derive differential and integral equations for the mean and covariance function
of the limit Gaussian process. This provides a method of tracking not only the
integral curve, but also the covariance matrix of its estimate. We also study
the asymptotic distribution of the squared minimal distance from the integral
curve to a smooth enough surface $\Gamma\subset G$. Building upon this, we
develop testing procedures for the hypothesis that the integral curve reaches
$\Gamma$. The problems of this nature are of interest in diffusion tensor
imaging, a brain imaging technique based on measuring the diffusion tensor at
discrete locations in the cerebral white matter, where the diffusion of water
molecules is typically anisotropic. The diffusion tensor data is used to
estimate the dominant orientations of the diffusion and to track white matter
fibers from the initial location following these orientations. Our approach
brings more rigorous statistical tools to the analysis of this problem
providing, in particular, hypothesis testing procedures that might be useful in
the study of axonal connectivity of the white matter.


title: EPR Paradox,Locality and Completeness of Quantum Theory

abstract:
  The quantum theory (QT) and new stochastic approaches have no deterministic
prediction for a single measurement or for a single time -series of events
observed for a trapped ion, electron or any other individual physical system.
The predictions of QT being of probabilistic character apply to the statistical
distribution of the results obtained in various experiments. The probability
distribution is not an attribute of a dice but it is a characteristic of a
whole random experiment : '' rolling a dice''. and statistical long range
correlations between two random variables X and Y are not a proof of any causal
relation between these variable. Moreover any probabilistic model used to
describe a random experiment is consistent only with a specific protocol
telling how the random experiment has to be performed.In this sense the quantum
theory is a statistical and contextual theory of phenomena. In this paper we
discuss these important topics in some detail. Besides we discuss in historical
perspective various prerequisites used in the proofs of Bell and CHSH
inequalities concluding that the violation of these inequalities in spin
polarization correlation experiments is neither a proof of the completeness of
QT nor of its nonlocality. The question whether QT is predictably complete is
still open and it should be answered by a careful and unconventional analysis
of the experimental data. It is sufficient to analyze more in detail the
existing experimental data by using various non-parametric purity tests and
other specific statistical tools invented to study the fine structure of the
time-series. The correct understanding of statistical and contextual character
of QT has far reaching consequences for the quantum information and quantum
computing.


title:
Deformations of metabelian representations of knot groups into
  $SL(3,\mathbb{C})$

abstract:
  Let K be a knot in $S^3$ and $X$ its complement. We study deformations of
reducible metabelian representations of the knot group $\pi_1(X)$ into
$SL(3,\mathbb{C})$ which are associated to a double root of the Alexander
polynomial. We prove that these reducible metabelian representations are smooth
points of the representation variety and that they have irreducible non
metabelian deformations.