title:
In vivo endoscopic autofluorescence microspectro-imaging of bronchi and
  alveoli

abstract:
  Fibered confocal fluorescence microscopy (FCFM) is a new technique that can
be used during a bronchoscopy to analyze the nature of the human bronchial and
alveolar mucosa fluorescence microstructure. An endoscopic fibered confocal
fluorescence microscopy system with spectroscopic analysis capability was
developed allowing real-time, simultaneous images and emission spectra
acquisition at 488 nm excitation using a flexible miniprobe that could be
introduced into small airways. This flexible 1.4 mm miniprobe can be introduced
into the working channel of a flexible endoscope and gently advanced through
the bronchial tree to the alveoli. FCFM in conjunction with bronchoscopy is
able to image the in vivo autofluorescence structure of the bronchial mucosae
but also the alveolar respiratory network outside of the usual field of view.
Microscopic and spectral analysis showed that the signal mainly originates from
the elastin component of the bronchial subepithelial layer. In non smokers, the
system images the elastin backbone of the aveoli. In active smokers, a strong
autofluorescence signal appears from alveolar macrophages. The FCFM technique
appears promising for in vivo exploration of the bronchial and alveolar
extracellular matrix.


title: Pattern-Oriented Analysis and Design (POAD) Theory

abstract:
  Pattern-Oriented Analysis and Design (POAD) is the practice of building
complex software by applying proven designs to specific problem domains.
Although a great deal of research and practice has been devoted to formalizing
existing design patterns and discovering new ones, there has been relatively
little research into methods for combining these patterns into software
applications. This is partly because the creation of complex software
applications is so expensive. This paper proposes a mathematical model of POAD
that may allow future research in pattern-oriented techniques to be performed
using less expensive formal techniques rather than expensive, complex software
development.


title: Testing Lorentz and CPT Invariance with MINOS Near Detector Neutrinos

abstract:
  We present an analysis designed to search for Lorentz and CPT violations as
predicted by the SME framework using the charged current neutrino events in the
MINOS near detector. In particular we develop methods to identify periodic
variations in the normalized number of charged current neutrino events as a
function of sidereal phase. To test these methods, we simulated a set of 1,000
experiments without Lorentz and CPT violation signals using the standard MINOS
Monte Carlo. We performed an FFT on each of the simulated experiments to find
the distribution of powers in the sidereal phase diagram without a signal. We
then injected a signal of increasing strength into the sidereal neutrino
oscillation probability until we found a 5$\sigma$ deviation from the mean in
the FFT power spectrum. By this method, we can establish upper limits for the
Lorentz and CPT violating terms in the SME.


title: A First Approximation for Quantization of Singular Spaces

abstract:
  Many mathematical models of physical phenomena that have been proposed in
recent years require more general spaces than manifolds. When taking into
account the symmetry group of the model, we get a reduced model on the
(singular) orbit space of the symmetry group action. We investigate
quantization of singular spaces obtained as leaf closure spaces of regular
Riemannian foliations on compact manifolds. These contain the orbit spaces of
compact group actions and orbifolds. Our method uses foliation theory as a
desingularization technique for such singular spaces. A quantization procedure
on the orbit space of the symmetry group - that commutes with reduction - can
be obtained from constructions which combine different geometries associated
with foliations and new techniques originated in Equivariant Quantization. The
present paper contains the first of two steps needed to achieve these just
detailed goals.


title: Interstellar Dust Inside and Outside the Heliosphere

abstract:
  In the early 1990s, after its Jupiter flyby, the Ulysses spacecraft
identified interstellar dust in the solar system. Since then the in-situ dust
detector on board Ulysses continuously monitored interstellar grains with
masses up to 10e-13 kg, penetrating deep into the solar system. While Ulysses
measured the interstellar dust stream at high ecliptic latitudes between 3 and
5 AU, interstellar impactors were also measured with the in-situ dust detectors
on board Cassini, Galileo and Helios, covering a heliocentric distance range
between 0.3 and 3 AU in the ecliptic plane. The interstellar dust stream in the
inner solar system is altered by the solar radiation pressure force,
gravitational focussing and interaction of charged grains with the time varying
interplanetary magnetic field. The grains act as tracers of the physical
conditions in the local interstellar cloud (LIC). Our in-situ measurements
imply the existence of a population of 'big' interstellar grains (up to 10e-13
kg) and a gas-to-dust-mass ratio in the LIC which is a factor of > 2 larger
than the one derived from astronomical observations, indicating a concentration
of interstellar dust in the very local interstellar medium. Until 2004, the
interstellar dust flow direction measured by Ulysses was close to the mean apex
of the Sun's motion through the LIC, while in 2005, the data showed a 30 deg
shift, the reason of which is presently unknown. We review the results from
spacecraft-based in-situ interstellar dust measurements in the solar system and
their implications for the physical and chemical state of the LIC.


title:
Security proof of quantum key distribution with detection efficiency
  mismatch

abstract:
  In theory, quantum key distribution (QKD) offers unconditional security based
on the laws of physics. However, as demonstrated in recent quantum hacking
theory and experimental papers, detection efficiency loophole can be fatal to
the security of practical QKD systems. Here, we describe the physical origin of
detection efficiency mismatch in various domains including spatial, spectral,
and time domains and in various experimental set-ups. More importantly, we
prove the unconditional security of QKD even with detection efficiency
mismatch. We explicitly show how the key generation rate is characterized by
the maximal detection efficiency ratio between the two detectors. Furthermore,
we prove that by randomly switching the bit assignments of the detectors, the
effect of detection efficiency mismatch can be completely eliminated.


title: Knowledge Technologies

abstract:
  Several technologies are emerging that provide new ways to capture, store,
present and use knowledge. This book is the first to provide a comprehensive
introduction to five of the most important of these technologies: Knowledge
Engineering, Knowledge Based Engineering, Knowledge Webs, Ontologies and
Semantic Webs. For each of these, answers are given to a number of key
questions (What is it? How does it operate? How is a system developed? What can
it be used for? What tools are available? What are the main issues?). The book
is aimed at students, researchers and practitioners interested in Knowledge
Management, Artificial Intelligence, Design Engineering and Web Technologies.
  During the 1990s, Nick worked at the University of Nottingham on the
application of AI techniques to knowledge management and on various knowledge
acquisition projects to develop expert systems for military applications. In
1999, he joined Epistemics where he worked on numerous knowledge projects and
helped establish knowledge management programmes at large organisations in the
engineering, technology and legal sectors. He is author of the book "Knowledge
Acquisition in Practice", which describes a step-by-step procedure for
acquiring and implementing expertise. He maintains strong links with leading
research organisations working on knowledge technologies, such as
knowledge-based engineering, ontologies and semantic technologies.


title:
B -> D tau nu Branching Ratios: Opportunity for Lattice QCD and Hadron
  Colliders

abstract:
  In the Standard Model, scalar contributions to leptonic and semileptonic
decays are helicity suppressed. The hypothesis of additional physical
neutral/charged Higgses can enhance such scalar contributions and give
detectable effects especially in B physics.
  For the charged Higgs, experimental information on both Br(B -> D tau nu) and
Br(B -> tau nu) has already become available and in particular the B -> D tau
nu branching ratio measurements will be further improved in the coming years.
Hadronic uncertainties of scalar contributions in semileptonic decays are
already in much better shape than the ones plaguing the helicity suppressed
leptonic decays B -> tau nu. Combining existing experimental information form
the B factories, we explore which existing and future lattice estimates will be
useful to directly address new physics effects from measurements of
Br(B_{u,d,s} -> D_{u,d,s} tau nu), which can be performed also at hadron
colliders.


title:
Constrained evolution in axisymmetry and the gravitational collapse of
  prolate Brill waves

abstract:
  This paper is concerned with the Einstein equations in axisymmetric vacuum
spacetimes. We consider numerical evolution schemes that solve the constraint
equations as well as elliptic gauge conditions at each time step. We examine
two such schemes that have been proposed in the literature and show that some
of their elliptic equations are indefinite, thus potentially admitting
nonunique solutions and causing numerical solvers based on classical relaxation
methods to fail. A new scheme is then presented that does not suffer from these
problems. We use our numerical implementation to study the gravitational
collapse of Brill waves. A highly prolate wave is shown to form a black hole
rather than a naked singularity.


title: The 2/3 - convergence rate for the Poisson bracket

abstract:
  In this paper we introduce a new method for approaching the C^0 - rigidity
results for the Poisson bracket. Using this method, we provide a different
proof for the lower semi-continuity under C^0 perturbations, for the uniform
norm of the Poisson bracket. We find the precise rate for the modulus of the
semi-continuity. This extends the previous results of Cardin-Viterbo, Zapolsky,
Entov and Polterovich. Using our method, we prove a C^0 - rigidity result in
the spirit of the work of Humiliere. We also discuss a general question of the
C^0 - rigidity for multilinear differential operators.


title: Interacting scalar field theory in $\kappa$-Minkowski spacetime

abstract:
  We construct an complex scalar field theory in $\kappa$-Minkowksi spacetime,
which respects $\kappa$-deformed Poincar\'e symmetry. One-loop calculation
shows that the theory is finite and needs finite renormalization to be
compatible with the $\kappa \to \infty$ limit. The loop result also has an
imaginary valued correction due to the complex poles present in the propagator.


title: Reflection and Refraction of Bose-condensate Excitations

abstract:
  We investigate the transmission and reflection of Bose-condensate excitations
in the low energy limit across a potential barrier separating two condensates
with different densities. The Bogoliubov excitation in the low energy limit has
the incident angle where the perfect transmission occurs. This condition
corresponds to the Brewster's law for the electromagnetic wave. The total
internal reflection of the Bogoliubov excitation is found to occur at a large
incident angle in the low energy limit. The anomalous tunneling named by Kagan
et al. [Yu. Kagan et al., Phys. Rev. Lett., 90, 130402 (2003)] can be
understood in terms of the impedance matching. In the case of the normal
incidence, comparison with the results in Tomonaga-Luttinger liquids is made.


title: Connectedness in graph limits

abstract:
  We define direct sums and a corresponding notion of connectedness for graph
limits. Every graph limit has a unique decomposition as a direct sum of
connected components. As is well-known, graph limits may be represented by
symmetric functions on a probability space; there are natural definitions of
direct sums and connectedness for such functions, and there is a perfect
correspondence with the corresponding properties of the graph limit. Similarly,
every graph limit determines an infinite random graph, which is a.s. connected
if and only if the graph limit is connected. There are also characterizations
in terms of the asymptotic size of the largest component in the corresponding
finite random graphs, and of minimal cuts in sequences of graphs converging to
a given limit.


title: A Brief Editorial on de Sitter Radiation via Tunneling

abstract:
  Very recently (by which we mean two days ago), Y. Sekiwa submitted a paper
[arXiv:0802.3266] that dismisses some previous calculations of the de Sitter
radiative temperature. Significantly, these calculations employed the
(so-called) tunneling methodology, which the stated author then goes on to
correspondingly revise. After briefly commenting on what the tunneling
framework can be claimed to say and what it cannot, we respond to the author's
criticisms and proposed revision.


title: Restricted Class of Colliding Einstein-Yang-Mills Plane Waves

abstract:
  By gauging an Abelian electromagnetic (em) solution through a non-Abelian
transformation and in accordance with a theorem proved long time ago, we
construct a simple class of colliding Einstein-Yang-Mills (EYM) plane waves.
The solution is isometric to the Wu-Yang charged Kerr-Newman (KN) black hole
and shares much of the properties satisfied by colliding Einstein-Maxwell (EM)
plane waves. In the linear polarization limit with unit degenerate charge it
reduces to the Bell-Szekeres (BS) solution for colliding em shock waves.


title: Microcanonical versus Canonical Analysis of Protein Folding

abstract:
  The microcanonical analysis is shown to be a powerful tool to characterize
the protein folding transition and to neatly distinguish between good and bad
folders. An off-lattice model with parameter chosen to represent polymers of
these two types is used to illustrate this approach. Both canonical and
microcanonical ensembles are employed. The required calculations were performed
using parallel tempering Monte Carlo simulations. The most revealing features
of the folding transition are related to its first-order-like character,
namely, the S-bend pattern in the caloric curve, which gives rise to negative
microcanonical specific heats, and the bimodality of the energy distribution
function at the transition temperatures. Models for a good folder are shown to
be quite robust against perturbations in the interaction potential parameters.


title:
Moufang symmetry XI. Integrability of generalized Lie equations of
  continuous Moufang transformations

abstract:
  Integrability of generalized Lie equations of continuous Moufang
transformations is inquired.


title:
Moufang symmetry XII. Reductivity and hidden associativity of
  infinitesimal Moufang transformations

abstract:
  It is shown how integrability of the generalized Lie equations of continous
Moufang transformatiosn is related to the reductivity conditions and
Sagle-Yamaguti identity.


title:
On the flat remainder in normal forms of families of analytic planar
  saddles

abstract:
  We give an explicit expression for the (finitely) flat remainder after
analytic normal form reduction of a family of planar saddles of diffeomorphisms
or vector fields. We distinguish between a rational or irrational ratio of the
moduli of the eigenvalues at the saddle for a certain value of the parameter.


title:
The Matrix Product Ansatz for integrable U(1)^N models in
  Lunin-Maldacena backgrounds

abstract:
  We obtain through a Matrix Product Ansatz (MPA) the exact solution of the
most general $N$-state spin chain with $U(1)^N$ symmetry and nearest neighbour
interaction. In the case N=6 this model contain as a special case the
integrable SO(6) spin chain related to the one loop mixing matrix for anomalous
dimensions in ${\cal N} = 4$ SYM, dual to type $IIB$ string theory in the
generalised Lunin-Maldacena backgrounds. This MPA is construct by a map between
scalar fields and abstract operators that satisfy an appropriate associative
algebra. We analyses the Yang-Baxter equation in the N=3 sector and the
consistence of the algebraic relations among the matrices defining the MPA and
find a new class of exactly integrable model unknown up to now.


title: On the nature of late X-ray flares in Swift Gamma-ray Bursts

abstract:
  Previously detected in only a few gamma-ray bursts (GRBs), X-ray flares are
now observed in ~50% of Swift GRBs, though their origins remain unclear. Most
flares are seen early on in the afterglow decay, while some bursts exhibit
flares at late times of 10^4 to 10^5 seconds, which may have implications for
flare models.We investigate whether a sample of late time (> 10^4s) flares are
different from previous samples of early time flares, or whether they are
merely examples on the tail of the early flare distribution. We examine the
X-ray light curves of Swift bursts for late flares and compare the flare and
underlying temporal power-law properties with those of early flares, and the
values of these properties predicted by the blast wave model. The burst sample
shows late flare properties consistent with those of early flares, where the
majority of the flares can be explained by either internal or external shock,
though in a few cases one origin is favoured over the other. The underlying
power laws are mainly consistent with the normal decay phases of the afterglow.
If confirmed by the ever growing sample of late time flares, this would imply
that, in some cases, prolonged activity out to a day or a restarting of the
central engine is required.


title: The Pressure of an Equilibrium Interstellar Medium in Galactic Disks

abstract:
  Based on an axisymmetric galactic disk model, we estimate the equilibrium gas
pressure P/k in the disk plane as a function of the galactocentric distance R
for several galaxies (MW, M33, M51, M81, M100, M101, M106, and the SMC). For
this purpose, we solve a self-consistent system of equations by taking into
account the gas self-gravity and the presence of a dark pseudo-isothermal halo.
We assume that the turbulent velocity dispersions of the atomic and molecular
gases are fixed and that the velocity dispersion of the old stellar disk
corresponds to its marginal stability (except for the Galaxy and the SMC). We
also consider a model with a constant disk thickness. Of the listed galaxies,
the SMC and M51 have the highest pressure at a given relative radius R/R_25,
while M81 has the lowest pressure. The pressure dependence of the relative
molecular gas fraction confirms the existence of a positive correlation between
these quantities, but it is not so distinct as that obtained previously when
the pressure was estimated very roughly. This dependence breaks down for the
inner regions of M81 and M106, probably because the gas pressure has been
underestimated in the bulge region. We discuss the possible effects of factors
other than the pressure affecting the relative content of molecular gas in the
galaxies under consideration.


title: A Cosmic Ray Resolution to the Superbubble Energy-Crisis

abstract:
  Superbubbles (SBs) are amongst the greatest injectors of energy into the
Galaxy, and have been proposed to be the acceleration site of Galactic cosmic
rays. They are thought to be powered by the fast stellar winds and powerful
supernova explosions of massive stars in dense stellar clusters and
associations. Observations of the SB 'DEM L192' in the neighboring Large
Magellenic Cloud (LMC) galaxy show that it contains only about one-third the
energy injected by its constituent stars via fast stellar winds and supernovae.
It is not yet understood where the excess energy is going, thus, the so-called
'energy crisis'. We show here that it is very likely that a significant
fraction of the unaccounted for energy is being taken up in accelerating cosmic
rays, thus bolstering the argument for the SB origin of cosmic rays.


title:
On the potential value of Ca II K spectroheliogram time-series for solar
  activity and irradiance studies

abstract:
  Various observatories around the globe started regular full-disk imaging of
the solar atmosphere in the Ca II K line since the early decades of the 20th
century. The archives made by these observations have the potential of
providing far more detailed information on solar magnetism than just the
sunspot number and area records to which most studies of solar activity and
irradiance changes are restricted. We evaluate the image contents of three Ca
II K spectroheliogram time-series, specifically those obtained by the
digitization of the Arcetri, Kodaikanal, and Mt Wilson photographic archives.
We describe the main problems afflicting these data and analyze their quality
by expressing the image contents through several quantities. We compare the
results obtained with those for similar present-day observations taken with the
Meudon spectroheliograph and with the Rome-PSPT. We show that historic data
suffer from stronger geometrical distortions and photometric uncertainties than
similar present-day observations. The latter uncertainties mostly originate
from the photographic calibration of the original data and from stray-light
effects. We also show that the image contents of the three analyzed series vary
in time. These variations are probably due to instrument changes and aging of
the spectrographs used, as well as changes of the observing programs. Our
results imply that the main challenge for the analysis of historic data is
their accurate photometric calibration. This problem must be solved before they
can provide reliable information about solar magnetism and activity over the
last century. Moreover, inter-calibration of results obtained from independent
time-series is required to reliably trace changes of solar properties with time
from the analysis of such data.


title: Representability of Hilbert schemes and Hilbert stacks of points

abstract:
  We show that the Hilbert functor of points on an arbitrary separated
algebraic stack is an algebraic space. We also show the algebraicity of the
Hilbert stack of points on an algebraic stack and the algebraicity of the Weil
restriction of an algebraic stack along a finite flat morphism. For the latter
two results, no separation assumptions are necessary.


title: Two-channel Feshbach physics in a structured continuum

abstract:
  We analyze the scattering and bound state physics of a pair of atoms in a
one-dimensional optical lattice interacting via a narrow Feshbach resonance.
The lattice provides a structured continuum allowing for the existence of bound
dimer states both below and above the continuum bands, with pairs above the
continuum stabilized by either repulsive interactions or their center of mass
motion. Inside the band the Feshbach coupling to a closed channel bound state
leads to a Fano resonance profile for the transmission, which may be mapped out
by RF- or photodissociative spectroscopy. We generalize the scattering length
concept to the one-dimensional lattice, where a scattering length may be
defined at both the lower and the upper continuum thresholds. As a function of
the applied magnetic field the scattering length at either band edge exhibits
the usual Feshbach divergence when a bound state enters or exits the continuum.
Near the scattering length divergences the binding energy and wavefunction of
the weakly bound dimer state acquires a universal form reminiscent of those of
free-space Feshbach molecules. We give numerical examples of our analytic
results for a specific Feshbach resonance, which has been studied
experimentally.


title: A Weak Chevalley-Warning Theorem for Quasi-finite Fields

abstract:
  There exists a function f: N -> N such that for every positive integer d,
every quasi-finite field K and every projective hypersurface X of degree d and
dimension at least f(d), the set X(K) is non-empty. This is a special case of a
more general result about intersections of hypersurfaces of fixed degree in
projective spaces of sufficiently high dimension over fields with finitely
generated Galois groups.


title:
High-resolution mapping of flows in the solar interior: Fully consistent
  OLA inversion of helioseismic travel times

abstract:
  To recover the flow information encoded in travel-time data of time-distance
helioseismology, accurate forward modeling and a robust inversion of the travel
times are required. We accomplish this using three-dimensional finite-frequency
travel-time sensitivity kernels for flows along with a 2+1 dimensional (2+1D)
optimally localized averaging (OLA) inversion scheme. Travel times are measured
by ridge filtering MDI full-disk Doppler data and the corresponding Born
sensitivity kernels are computed for these particular travel times. We also
utilize the full noise covariance properties of the travel times which allow us
to accurately estimate the errors for all inversions. The whole procedure is
thus fully consistent. Due to ridge filtering, the kernel functions separate in
the horizontal and vertical directions, motivating our choice of a 2+1D
inversion implementation. The inversion procedure also minimizes cross-talk
effects among the three flow components, and the averaging kernels resulting
from the inversion show very small amounts of cross-talk. We obtain
three-dimensional maps of vector solar flows in the quiet Sun at spatial
resolutions of 7-10 Mm using generally 24 h of data. For all of the flow maps
we provide averaging kernels and the noise estimates. We present examples to
test the inferred flows, such as a comparison with Doppler data, in which we
find a correlation of 0.9. We also present results for quiet-Sun supergranular
flows at different depths in the upper convection zone.


title: Interfaces in driven Ising models: shear enhances confinement

abstract:
  We use a phase-separated driven two-dimensional Ising lattice gas to study
fluid interfaces exposed to shear flow parallel to the interface. The interface
is stabilized by two parallel walls with opposing surface fields and a driving
field parallel to the walls is applied which (i) either acts locally at the
walls or (ii) varies linearly with distance across the strip. Using computer
simulations with Kawasaki dynamics, we find that the system reaches a steady
state in which the magnetisation profile is the same as that in equilibrium,
but with a rescaled length implying a reduction of the interfacial width. An
analogous effect was recently observed in sheared phase-separated colloidal
dispersions. Pair correlation functions along the interface decay more rapidly
with distance under drive than in equilibrium and for cases of weak drive can
be rescaled to the equilibrium result.


title: Boundedness in Complex Systems: New Approach to Power Law Distributions

abstract:
  A new approach to complex systems aimed to resolve their paradoxes is
proposed. Yet, the major inference is the prohibition of informational
perpetuum mobile


title:
Spatially resolved spectroscopy of planetary nebulae and their halos I.
  Five galactic disk objects

abstract:
  Strong mass loss off stars at the tip of the asymptotic giant branch (AGB)
profoundly affects properties of these stars and their surroundings, including
the subsequent planetary nebula (PN) stage. With this study we wanted to
determine physical properties of mass loss by studying weakly emitting halos,
focusing on objects in the galactic disk. Halos surround the, up to several
thousand times, brighter central regions of PNe. Young halos, specifically,
still contain information of the preceeding final mass loss stage on the AGB.
In the observations we used the method of integral field spectroscopy with the
PMAS instrument. This is the first committed study of halos of PNe that uses
this technique. We improved our data analysis by a number of steps. In a study
of the influence of scattered light we found that a moderate fraction of
intensities in the inner halo originate in adjacent regions. As we combine line
intensities of distant wavelengths, and because radial intensity gradients are
steep, we corrected for effects of differential atmospheric refraction. In
order to increase the signal-to-noise of weak emission lines we introduced a
dedicated method to bin spectra of individual spatial elements. We also
developed a general technique to subtract telluric lines - without using
separate sky exposures. By these steps we avoided introducing errors of several
thousand Kelvin to our temperature measurements in the halo. For IC3568 we
detected a halo. For M2-2 we found a halo radius that is 2.5 times larger...
(abridged)


title: Single atom adhesion in optimized gold nanojunctions

abstract:
  We study the interaction between single apex atoms in a metallic contact,
using the break junction geometry. By carefully 'training' our samples, we
create stable junctions in which no further atomic reorganization takes place.
This allows us to study the relation between the so-called jump out of contact
(from contact to tunnelling regime) and jump to contact (from tunnelling to
contact regime) in detail. Our data can be fully understood within a relatively
simple elastic model, where the elasticity k of the electrodes is the only free
parameter. We find 5 < k < 32 N/m. Furthermore, the interaction between the two
apex atoms on both electrodes, observed as a change of slope in the tunnelling
regime, is accounted for by the same model.


title: Screening High-z GRBs with BAT Prompt Emission Properties

abstract:
  Detecting high-z GRBs is important for constraining the GRB formation rate,
and tracing the history of re-ionization and metallicity of the universe. Based
on the current sample of GRBs detected by Swift with known redshifts, we
investigated the relationship between red-shift, and spectral and temporal
characteristics, using the BAT event-by-event data. We found red-shift trends
for the peak-flux-normalized temporal width T90, the light curve variance, the
peak flux, and the photon index in simple power-law fit to the BAT event data.
We have constructed criteria for screening GRBs with high red-shifts. This will
enable us to provide a much faster alert to the GRB community of possible
high-z bursts.


title:
Study of $\eta$ photoproduction on the proton in a chiral constituent
  quark approach via one-gluon-exchange model

abstract:
  A formalism based on a chiral quark model ($\chi$QM) approach complemented
with a one-gluon exchange model, to take into account the breakdown of the
$SU(6)\otimes O(3)$ symmetry, is presented. The configuration mixing of wave
functions for nucleon and resonances are derived. % With few adjustable
parameters, differential cross-section and polarized beam asymmetry for the
$\gamma p \to \eta p$ process are calculated and successfully compared with the
data in the centre-of-mass energy range from threshold up to 2 GeV. The known
resonances $S_{11}(1535)$, $S_{11}(1650)$, $P_{13}(1720)$, $D_{13}(1520)$, and
$F_{15}(1680)$, as well as two new $S_{11}$ and $D_{15}$ resonances are found
to be dominant in the reaction mechanism. Besides, connections among the
scattering amplitudes of the $\chi$QM approach and the helicity amplitudes, as
well as decay widths of resonances are established. Possible contributions from
the so-called "missing resonances" are investigated and found to be negligible.


title:
Evidence for Charge Glass-like Behavior in Lightly Doped
  La_{2-x}Sr_{x}CuO_{4} at Low Temperatures

abstract:
  A c-axis magnetotransport and resistance noise study in
La_{1.97}Sr_{0.03}CuO_{4} reveals clear signatures of glassiness, such as
hysteresis, memory, and slow, correlated dynamics, but only at temperatures (T)
well below the spin glass transition temperature T_{sg}. The results strongly
suggest the emergence of charge glassiness, or dynamic charge ordering, as a
result of Coulomb interactions.


title:
Dynamical Structure Factor and Spin-Density Separation for a
  Weakly-Interacting Two-Component Bose Gas

abstract:
  We show that spin-density separation in a Bose gas is not restricted to 1D
but also occurs in higher dimension. The ratio ($\alpha$) of the intra-species
atom-atom interaction strength to the inter-species interaction strength,
strongly influences the dynamics of spin-density separation and the elementary
excitations. The density wave is phonon-like for all values of $\alpha$. For
$\alpha<1$, spin wave is also phonon-like. The spin waves have a quadratic
dispersion in the $\alpha=1$ coupling regime, while in the phase separated
regime ($\alpha>1$) the spin waves are found to be damped. The dynamical
structure factor (DSF) reveals two distinct peaks corresponding to the density
and spin waves for $\alpha \le 1$. For $\alpha > 1$ there is only one DSF peak
corresponding to the density wave.


title: Dirac structures of omni-Lie algebroids

abstract:
  Omni-Lie algebroids are generalizations of Alan Weinstein's omni-Lie
algebras. A Dirac structure in an omni-Lie algebroid $\dev E\oplus \jet E$ is
necessarily a Lie algebroid together with a representation on $E$. We study the
geometry underlying these Dirac structures in the light of reduction theory. In
particular, we prove that there is a one-to-one correspondence between
reducible Dirac structures and projective Lie algebroids in $\huaT=TM\oplus E$;
we establish the relation between the normalizer $N_{L}$ of a reducible Dirac
structure $L$ and the derivation algebra $\Der(\pomnib (L))$ of the projective
Lie algebroid $\pomnib (L)$; we study the cohomology group
$\mathrm{H}^\bullet(L,\rho_{L})$ and the relation between $N_{L}$ and
$\mathrm{H}^1(L,\rho_{L})$; we describe Lie bialgebroids using the adjoint
representation; we study the deformation of a Dirac structure $L$, which is
related with $\mathrm{H}^2(L,\rho_{L})$.


title: On the Kuratowski graph planarity criterion

abstract:
  This paper is purely expositional. The statement of the Kuratowski graph
planarity criterion is simple and well-known. However, its classical proof is
not easy. In this paper we present the Makarychev proof (with further
simplifications by Prasolov, Telishev, Zaslavski and the author) which is
possibly the simplest. In the Rusian version before the proof we present all
the necessary definitions, and afterwards we state some close results on graphs
and more general spaces. The paper is accessible for students familiar with the
notion of a graph, and could be an interesting easy reading for mature
mathematicians.


title:
The surfing effect in the interaction of electromagnetic and
  gravitational waves. Limits on the speed of gravitational waves

abstract:
  In the current work we investigate the propagation of electromagnetic waves
in the field of gravitational waves. Starting with simple case of an
electromagnetic wave travelling in the field of a plane monochromatic
gravitational wave we introduce the concept of surfing effect and analyze its
physical consequences. We then generalize these results to an arbitrary
gravitational wave field. We show that, due to the transverse nature of
gravitational waves, the surfing effect leads to significant observable
consequences only if the velocity of gravitational waves deviates from speed of
light. This fact can help to place an upper limit on the deviation of
gravitational wave velocity from speed of light. The micro-arcsecond resolution
promised by the upcoming precision interferometry experiments allow to place
stringent upper limits on $\epsilon = (v_{gw}-c)/c$ as a function of the energy
density parameter for gravitational waves $\Omega_{gw}$. For $\Omega_{gw}
\approx 10^{-10}$ this limit amounts to $\epsilon\lesssim 2\cdot 10^{-2}$.


title: Clones from ideals

abstract:
  On an infinite base set X, every ideal of subsets of X can be associated with
the clone of those operations on X which map small sets to small sets. We
continue earlier investigations on the position of such clones in the clone
lattice.


title:
Space VLBI polarimetry of IDV sources: Lessons from VSOP and prospects
  for VSOP2

abstract:
  To locate and image the compact emission regions in quasars, which are
closely connected to the phenomenon of IntraDay Variability (IDV), space VLBI
observations are of prime importance. Here we report on VSOP observations of
two prominent IDV sources, the BL Lac objects S5 0716+714. To monitor their
short term variability, these sources were observed with VSOP at 5 GHz in
several polarisation sensitive experiments, separated in time by one day to six
days, in autumn 2000. Contemporaneous flux density measurements with the
Effelsberg 100m radio telescope were used to directly compare the single dish
IDV with changes of the VLBI images. A clear IDV behaviour in total intensity
and linear polarization was observed in 0716+714. Analysis of the VLBI data
shows that the variations are located inside the VLBI core component of
0716+714. In good agreement with the single-dish measurements, the VLBI ground
array images and the VSOP images, both show a decrease in the total flux
density of ~20 mJy and a drop of ~5 mJy in the linear polarization of the VLBI
core. No variability was found in the jet. From the variability timescales we
estimate a source size of a few micro-arcseconds and brightness temperatures
exceeding 10^15 K. Independent of whether the interpretation of the IDV seen in
the VLBI core is source intrinsic or extrinsic a lower limit of T_B > 2x10^12 K
is obtained by model fitting of the VLBI-core. Our results show that future
VSOP2 observations should be accompanied by a single dish monitoring not only
to discriminate between source-extrinsic and source-intrinsic effects but to
allow also a proper calibration and interpretation of ultra-high resolution
VSOP2 images.


title:
A new result on the Klein-Gordon equation in the background of a
  rotating black hole

abstract:
  This short paper should serve as basis for further analysis of a previously
found new symmetry of the solutions of the wave equation in the gravitational
field of a Kerr black hole. Its main new result is the proof of essential
self-adjointness of the spatial part of a reduced normalized wave operator of
the Kerr metric in a weighted L^2-space. As a consequence, it leads to a purely
operator theoretic proof of the well-posedness of the initial value problem of
the reduced Klein-Gordon equation in that field in that L^2-space and in this
way generalizes a corresponding result of Kay (1985) in the case of the
Schwarzschild black hole. It is believed that the employed methods are
applicable to other separable wave equations.


title: Pro-p groups of positive deficiency

abstract:
  Let \Gamma be a finitely presentable pro-p group with a nontrivial finitely
generated closed normal subgroup N of infinite index. Then def(\Gamma)\leq 1,
and if def(\Gamma)=1 then \Gamma is a pro-p duality group of dimension 2, N is
a free pro-p group and \Gamma/N is virtually free. In particular, if the centre
of \Gamma is nontrivial and def(\Gamma)\geq 1, then def(\Gamma)=1, cd G \leq 2
and \Gamma is virtually a direct product F \times Z_p, with F a finitely
generated free pro-p group.


title:
The Influence of Helical Magnetic Fields in the Dynamics and Emission of
  Relativistic Jets

abstract:
  We present numerical relativistic magnetohydrodynamic and emission
simulations aimed to study the role played by the magnetic field in the
dynamics and emission of relativistic jets in Active Galactic Nuclei. We focus
our analysis on the study of the emission from recollimation shocks since they
may provide an interpretation for the stationary components seen at
parsec-scales in multiple sources. We show that the relative brightness of the
knots associated with the recollimation shocks decreases with increasing jet
magnetization, suggesting that jets presenting stationary components may have a
relatively weak magnetization, with magnetic fields of the order of
equipartition or below.


title: Galactic globular clusters contribution to microlensing events?

abstract:
  In this note we perform an analysis of the large set of microlensing events
detected so far toward the Galactic center with the purpose of investigating
whether some of the dark lenses are located in Galactic globular clusters. We
find that in four cases some events might indeed be due to lenses located in
the globular clusters themselves. We also give a rough estimate for the average
lens mass of the subset of events being highly aligned with Galactic globular
cluster centers and find that, under reasonable assumptions, the deflectors
could most probably be either brown dwarfs, M-stars or stellar remnants.


title:
Decoherence by a spin thermal bath: Role of the spin-spin interactions
  and initial state of the bath

abstract:
  We study the decoherence of two coupled spins that interact with a spin-bath
environment. It is shown that the connectivity and the coupling strength
between the spins in the environment are of crucial importance for the
decoherence of the central system. For the anisotropic spin-bath, changing the
connectivity or coupling strenghts changes the decoherence of the central
system from Gaussian to exponential decay law. The initial state of the
environment is shown to affect the decoherence process in a qualitatively
significant manner.


title:
Magnetic monopoles and center vortices as gauge-invariant topological
  defects simultaneously responsible for confinement

abstract:
  We give a gauge-invariant definition of the vortex surface in SU(N)
Yang-Mills theory without using the gauge fixing procedure. In this
construction, gauge-invariant magnetic monopoles with fractional magnetic
charges emerge in the boundary of the non-oriented vortex surface such that the
asymptotic string tension reproduces the correct $N$-ality dependence. We show
that gauge-invariant magnetic monopoles and vortices are simultaneously
responsible for quark confinement in four dimensional spacetime based on the
Wilson criterion. These results are extracted from a non-Abelian Stokes theorem
derived in the previous paper.


title: WMAP Haze: Directly Observing Dark Matter?

abstract:
  In this paper we show that dark matter in the form of dense matter/antimatter
nuggets could provide a natural and unified explanation for several distinct
bands of diffuse radiation from the core of the Galaxy spanning over 12 orders
of magnitude in frequency. We fix all of the phenomenological properties of
this model by matching to x-ray observations in the keV band, and then
calculate the unambiguously predicted thermal emission in the microwave band,
at frequencies smaller by 10 orders of magnitude. Remarkably, the intensity and
spectrum of the emitted thermal radiation are consistent with--and could
entirely explain--the so-called "WMAP haze": a diffuse microwave excess
observed from the core of our Galaxy by the Wilkinson Microwave Anisotropy
Probe (WMAP). This provides another strong constraint of our proposal, and a
remarkable nontrivial validation. If correct, our proposal identifies the
nature of the dark matter, explains baryogenesis, and provides a means to
directly probe the matter distribution in our Galaxy by analyzing several
different types of diffuse emissions.


title:
Fluctuation diamagnetism around the superconducting transition in a
  cuprate crystal with a reduced Meissner fraction

abstract:
  The magnetization around the superconducting transition was measured in a
Tl$_{0.5}$Pb$_{0.5}$Sr$_2$CaCu$_2$O$_7$ crystal affected by a considerable
reduction ($\sim$55%) of its effective superconducting volume fraction but
still with a relatively sharp low-field Meissner transition, a behaviour that
may be attributed to the presence of structural inhomogeneities. By taking into
account these inhomogeneities just through the Meissner fraction, the observed
diamagnetism may still be explained, consistently above and below the
superconducting transition, in terms of the conventional Ginzburg-Landau
approach with fluctuations of Cooper pairs and vortices.


title: Searching for Strange Hypergeometric Identities By Sheer Brute Force

abstract:
  We describe a systematic search for all strange hypergeometric identities up
to a certain complexity with sheer brute force that lead us to the discovery of
two new infinite families of closed-form evaluations.


title:
Ghost contributions to charmonium production in polarized high-energy
  collisions

abstract:
  In a previous paper [Phys. Rev. D 68, 034017 (2003)], we investigated the
inclusive production of prompt J/psi mesons in polarized hadron-hadron,
photon-hadron, and photon-photon collisions in the factorization formalism of
nonrelativistic quantum chromodynamics providing compact analytic results for
the double longitudinal-spin asymmetry A_{LL}. For convenience, we adopted a
simplified expression for the tensor product of the gluon polarization
four-vector with its charge conjugate, at the expense of allowing for ghost and
anti-ghosts to appear as external particles. While such ghost contributions
cancel in the cross section asymmetry A_{LL} and thus were not listed in our
previous paper, they do contribute to the absolute cross sections. For
completeness and the reader's convenience, they are provided in this addendum.


title:
Bifurcations as dissociation mechanism in bichromatically driven
  diatomic molecules

abstract:
  We discuss the influence of periodic orbits on the dissociation of a model
diatomic molecule driven by a strong bichromatic laser fields. Through the
stability of periodic orbits we analyze the dissociation probability when
parameters like the two amplitudes and the phase lag between the laser fields,
are varied. We find that qualitative features of dissociation can be reproduced
by considering a small set of short periodic orbits. The good agreement with
direct simulations demonstrates the importance of bifurcations of short
periodic orbits in the dissociation dynamics of diatomic molecules.


title: Khovanov homology and tight contact structures

abstract:
  Using the relation between Khovanov homology and the Heegaard Floer homology
of branched double covers, we show how Khovanov homology can be used to
establish tightness of branched double covers of certain transverse knots. We
give examples of several infinite families of knots whose branched covers are
tight for Khovanov-homological reasons, and show that some of these branched
covers are not Stein fillable.


title: The universal Hopf algebra associated with a Hopf-Lie-Rinehart algebra

abstract:
  We introduce a notion of Hopf-Lie-Rinehart algebra and show that the
universal algebra of a Hopf-Lie-Rinehart algebra acquires an ordinary Hopf
algebra structure.


title: Search for long lived heaviest nuclei beyond the valley of stability

abstract:
  The existence of long lived superheavy nuclei (SHN) is controlled mainly by
spontaneous fission and $\alpha$-decay processes. According to microscopic
nuclear theory, spherical shell effects at Z=114, 120, 126 and N=184 provide
the extra stability to such SHN to have long enough lifetime to be observed. To
investigate whether the so-called "stability island" could really exist around
the above Z, N values, the $\alpha$-decay half lives along with the spontaneous
fission and $\beta$-decay half lives of such nuclei are studied. The
$\alpha$-decay half lives of SHN with Z=102-120 are calculated in a quantum
tunneling model with DDM3Y effective nuclear interaction using $Q_\alpha$
values from three different mass formulae prescribed by Koura, Uno, Tachibana,
Yamada (KUTY), Myers, Swiatecki (MS) and Muntian, Hofmann, Patyk, Sobiczewski
(MMM). Calculation of spontaneous fission (SF) half lives for the same SHN are
carried out using a phenomenological formula and compared with SF half lives
predicted by Smolanczuk {\it et al}. Possible source of discrepancy between the
calculated $\alpha$-decay half lives of some nuclei and the experimental data
of GSI, JINR-FLNR, RIKEN are discussed. In the region of Z=106-108 with N$\sim$
160-164, the $\beta$-stable SHN $^{268}_{106}Sg_{162}$ is predicted to have
highest $\alpha$-decay half life ($T_\alpha \sim 3.2hrs$) using $Q_\alpha$
value from MMM. Interestingly, it is much greater than the recently measured
$T_\alpha$ ($\sim 22s$) of deformed doubly magic $^{270}_{108}Hs_{162}$
nucleus. A few fission-survived long-lived SHN which are either $\beta$-stable
or having large $\beta$-decay half lives are predicted to exist near
$^{294}110_{184}$, $^{293}110_{183}$, $^{296}112_{184}$ and $^{298}114_{184}$.
These nuclei might decay predominantly through $\alpha$-particle emission.


title:
On the nature of the so-called generic instabilities in dissipative
  relativistic hydrodynamics

abstract:
  It is shown that the so-called generic instabilities that appear in the
framework of relativistic linear irreversible thermodynamics, describing the
fluctuations of a simple fluid close to equilibrium, arise due to the coupling
of heat with hydrodynamic acceleration which appears in Eckart's formalism of
relativistic irreversible thermodynamics. Further, we emphasize that such
behavior should be interpreted as a contradiction to the postulates of linear
irreversible thermodynamics (LIT), namely a violation of Onsager's hypothesis
on the regression of fluctuations, and not as fluid instabilities. Such
contradictions can be avoided within a relativistic linear framework if a
Meixner-like approach to the phenomenological equations is employed.


title: Quadratic equations over free groups are NP-complete

abstract:
  We prove that the problems of deciding whether a quadratic equation over a
free group has a solution is NP-complete.


title: A note on three dimensional good sets

abstract:
  We show that as in the case of n- fold Cartesian product for n greater than
or equal to 4, even in 3-fold Cartesian product, a related component of a good
set need not be a full component.


title:
Discovery of very-high-energy gamma-ray emission from the vicinity of
  PSR J1913+1011 with H.E.S.S

abstract:
  The H.E.S.S. experiment, an array of four Imaging Atmospheric Cherenkov
Telescopes with high sensitivity and large field-of-view, has been used to
search for emitters of very-high-energy (VHE, >100 GeV) gamma-rays along the
Galactic plane, covering the region 30 deg < l < 60 deg, 280 deg < l < 330 deg,
and -3 deg < b < 3 deg. In this continuation of the H.E.S.S. Galactic Plane
Scan, a new extended VHE gamma-ray source was discovered at
alpha(2000)=19h12m49s, delta(2000)=+10d09'06'' (HESS J1912+101). Its integral
flux between 1-10 TeV is ~10% of the Crab Nebula flux in the same energy range.
The measured energy spectrum can be described by a power law with a photon
index Gamma = 2.7+-0.2(stat)+-0.3(sys). HESS J1912+101 is plausibly associated
with the high spin-down luminosity pulsar PSR J1913+1011. We also discuss
associations with an as yet unconfirmed SNR candidate proposed from low
frequency radio observation and/or with molecular clouds found in 13CO data.


title:
Automatic Transversality and Orbifolds of Punctured Holomorphic Curves
  in Dimension Four

abstract:
  We derive a numerical criterion for J-holomorphic curves in 4-dimensional
symplectic cobordisms to achieve transversality without any genericity
assumption. This generalizes results of Hofer-Lizan-Sikorav and
Ivashkovich-Shevchishin to allow punctured curves with boundary that generally
need not be somewhere injective or immersed. As an application, we combine this
with the intersection theory of punctured holomorphic curves to prove that
certain geometrically natural moduli spaces are globally smooth orbifolds,
consisting generically of embedded curves, plus unbranched multiple covers that
form isolated orbifold singularities.


title: Computational class field theory

abstract:
  Class field theory furnishes an intrinsic description of the abelian
extensions of a number field that is in many cases not of an immediate
algorithmic nature. We outline the algorithms available for the explicit
computation of such extensions.


title: Extended orbital resonance model with hump-induced oscillations

abstract:
  Change of sign of the LNRF-velocity gradient has been found for accretion
discs orbiting rapidly rotating Kerr black holes with spin a > 0.9953 for
Keplerian discs and a > 0.99979 for marginally stable thick discs. Such a
"humpy" LNRF-velocity profiles occur just above the marginally stable circular
geodesic and could be related to oscillations of accretion discs. The frequency
of such "hump"-induced oscillations can be identified with the maximal rate of
change of the orbital velocity within the "humpy" profile. Therefore, we
introduce an extended orbital resonance model (EXORM) of quasiperiodic
oscillations (QPOs) assuming non-linear resonant phenomena between oscillations
with the orbital epicyclic frequencies and the humpy frequency defined in a
fully general relativistic way. The EXORM is developed for both Keplerian discs
and perfect-fluid tori where the approximation of oscillations with epicyclic
frequencies is acceptable. Clearly, the EXORM could be applied to the
near-extreme Kerr black hole systems exhibiting relatively complex QPO
frequency patterns. Assuming a Keplerian disc, it can be shown that in the
framework of the EXORM, all the QPOs observed in the microquasar GRS 1915+105
could be explained, while it is not possible in the case of QPOs observed in
the Galactic Centre source Sgr A*.


title:
Muons enhancements at sea level in association with Swift-BAT and
  MILAGRO triggers

abstract:
  Recently, triggers occurring during high background rate intervals have been
reporter by Swift-BAT Gamma Ray Burst (GRB) detector. Among them, there were
two on January 24, two on January 25, and two on February 13, and 18, all in
2008. These Swift-BAT triggers in most cases are probably noise triggers that
occurred while Swift was entering the South Atlantic Anomaly (SAA). In fact, we
show that they happen during a plentiful precipitation of high energy particles
in the SAA, producing muons in the atmosphere detected by two directional
telescopes at sea level, inside the SAA region (Tupi experiment). They look
like sharp peaks in the muon counting rate. In the same category are two
triggers from MILAGRO ground based detector, on January 25 and 31, 2008
respectively. In addition, the trigger coordinates are close to (and, in two
cases, inside) the field of view of the telescopes. From an additional analysis
in the behavior of the muon counting rate, it is possible to conclude that the
events are produced by precipitation of high energy charged particles in the
SAA region. Thus, due to its localization, the Tupi experiment constitutes a
new sensor of high energy particle precipitation in the SAA, and it can be
useful in the identification of some triggers of Gamma Ray Burst detectors.


title: Simbol-X background simulation activities

abstract:
  Using the Geant4 toolkit, a Monte-Carlo code to simulate the detector
background of the Simbol-X focal plane instrument has been developed with the
aim to optimize the design of the instrument. Structural design models of the
mirror and detector satellites have been built and used as baseline for our
simulations, to evaluate the different background contributions that must be
taken into account to determine the sensitivity of the Simbol-X detectors. We
work towards a simulation based background and mass model which can be used
before and during the mission.
  For different material compositions, material thicknesses, locations etc. the
response of the instrument to the diffuse cosmic hard X-ray background and to
the cosmic proton induced background have been calculated. As a result we
present estimates of the background count rate expected in the low and high
energy detector, and anti-coincidence rates. The effect of induced
radioactivity in the detector and shielding materials and soft proton
scattering in the mirror shells are also under study.


title:
Z_2-Singlino Dark Matter in a Portal-Like Extension of the Minimal
  Supersymmetric Standard Model

abstract:
  We propose a Z_2-stabilised singlino (\bar{\chi}) as a dark matter candidate
in extended and R-parity violating versions of the supersymmetric standard
model. \bar{\chi} interacts with visible matter via a heavy messenger field S,
which results in a supersymmetric version of the Higgs portal interaction. The
relic abundance of \bar{\chi} can account for cold dark matter if the messenger
mass satisfies M_S \lsim 10^{4} GeV. Our model can be implemented in many
realistic supersymmetric models such as the NMSSM and nMSSM.


title: Stability of helium accretion discs in ultracompact binaries

abstract:
  Stellar companions of accreting neutron stars in ultra compact X-ray binaries
(UCXBs) are hydrogen-deficient. Their helium or C/O accretion discs are
strongly X-ray irradiated. Both the chemical composition and irradiation
determine the disc stability with respect to thermal and viscous perturbations.
At shorter periods, UCXBs are persistent, whereas longer-period systems are
mostly transient. To understand this behaviour one has to derive the stability
criteria for X-ray irradiated hydrogen-poor accretion discs. We use a modified
and updated version of the Dubus et al. code describing time-dependent
irradiated accretion discs around compact objects. We obtained the relevant
stability criteria and compared the results to observed properties of UCXBs.
Although the general trend in the stability behaviour of UCXBs is consistent
with the prediction of the disc instability model, in a few cases the
inconsistency of theoretical predictions with the system observed properties is
weak enough to be attributed to observational and/or theoretical uncertainties.
Two systems might require the presence of some amount of hydrogen in the donor
star.


title:
Hamiltonian formulation and analysis of a collisionless fluid
  reconnection model

abstract:
  The Hamiltonian formulation of a plasma four-field fluid model that describes
collisionless reconnection is presented. The formulation is noncanonical with a
corresponding Lie-Poisson bracket. The bracket is used to obtain new
independent families of invariants, so-called Casimir invariants, three of
which are directly related to Lagrangian invariants of the system. The Casimirs
are used to obtain a variational principle for equilibrium equations that
generalize the Grad-Shafranov equation to include flow. Dipole and homogeneous
equilibria are constructed. The linear dynamics of the latter is treated in
detail in a Hamiltonian context: canonically conjugate variables are obtained;
the dispersion relation is analyzed and exact thresholds for spectral stability
are obtained; the canonical transformation to normal form is described; an
unambiguous definition of negative energy modes is given; and thresholds
sufficient for energy-Casimir stability are obtained. The Hamiltonian
formulation also is used to obtain an expression for the collisionless
conductivity and it is further used to describe the linear growth and nonlinear
saturation of the collisionless tearing mode.


title:
Spin-polarized collision of deuterium and tritium: Relativistic
  Kinematics

abstract:
  We investigate the relativistic kinematics of the spin-polarized collision of
deuterium incident on tritium, producing ${}^4$He and a neutron. Within the
context of special relativity, we apply the conservation of four momentum and
the conservation of intrinsic spin, which leads to a system of ten equations.
We impose initial conditions such that the deuterium is moving along the
x-axis, the tritium is stationary at the origin of coordinates, and the
classical spin vector of the deuterium (spin magnitude = 1) is along the
+z-axis, while the classical spin vector for tritium (spin magnitude = 1/2) is
along the $-$z-axis. We expand the ten conservation equations to second order
in velocities and we solve them for the velocity components of the neutron, its
unit-spin-orientation vector, and the velocity components of the ${}^4$He
nucleus, as a function of the incident deuterium energy. We find that this
analytic solution agrees closely with the numerical solution of the ten
(unexpanded) equations. For a given energy of deuterium, we find that there are
two solutions, each solution having a unique velocity for the emitted neutron
and helium nucleus. The two solutions are related to each other by reflection
in the plane perpendicular to the deuterium spin and containing the initial
deuterium velocity vector.


title:
Joint Source Channel Coding with Side Information Using Hybrid Digital
  Analog Codes

abstract:
  We study the joint source channel coding problem of transmitting an analog
source over a Gaussian channel in two cases - (i) the presence of interference
known only to the transmitter and (ii) in the presence of side information
known only to the receiver. We introduce hybrid digital analog forms of the
Costa and Wyner-Ziv coding schemes. Our schemes are based on random coding
arguments and are different from the nested lattice schemes by Kochman and
Zamir that use dithered quantization. We also discuss superimposed digital and
analog schemes for the above problems which show that there are infinitely many
schemes for achieving the optimal distortion for these problems. This provides
an extension of the schemes by Bross et al to the interference/side information
case. We then discuss applications of the hybrid digital analog schemes for
transmitting under a channel signal-to-noise ratio mismatch and for
broadcasting a Gaussian source with bandwidth compression.


title: EIT and TRACE responses to flare plasma

abstract:
  Aims: To understand the contribution of active region and flare plasmas to
the $\lambda$195 channels of SOHO/EIT (Extreme-ultraviolet Imaging Telescope)
and TRACE (Transition Region and Coronal Explorer).
  Methods: We have analysed an M8 flare simultaneously observed by the Coronal
Diagnostic Spectrometer (CDS), EIT, TRACE and RHESSI. We obtained synthetic
spectra for the flaring region and an outer region using the differential
emission measures (DEM) of emitting plasma based on CDS and RHESSI observations
and the CHIANTI atomic database. We then predicted the EIT and TRACE count
rates.
  Results: For the flaring region, both EIT and TRACE images taken through the
$\lambda$195 filter are dominated by Fe ${\rm XXIV}$ (formed at about 20 MK).
However, in the outer region, the emission was primarily due to the Fe${\rm
XII}$, with substantial contributions from other lines. The average count rate
for the outer region was within 25% the observed value for EIT, while for TRACE
it was a factor of two higher. For the flare region, the predicted count rate
was a factor of two (in case of EIT) and a factor of three (in case of TRACE)
higher than the actual count rate.
  Conclusions: During a solar flare, both TRACE and EIT $\lambda$195 channels
are found to be dominated by Fe ${\rm XXIV}$ emission. Reasonable agreement
between predictions and observations is found, however some discrepancies need
to be further investigated.


title:
On the interpretative essence of the term "interaction-free
  measurement": The role of entanglement

abstract:
  The polemical term "interaction-free measurement" (IFM) is analyzed in its
interpretative nature. Two seminal works proposing the term are revisited and
their underlying interpretations are assessed. The role played by nonlocal
quantum correlations (entanglement) is formally discussed and some
controversial conceptions in the original treatments are identified. As a
result the term IFM is shown to be consistent neither with the standard
interpretation of quantum mechanics nor with the lessons provided by the EPR
debate.


title: Vortices in brain waves

abstract:
  Interactions by mutual excitation in neural populations in human and animal
brains create a mesoscopic order parameter that is recorded in brain waves
(electroencephalogram, EEG). Spatially and spectrally distributed oscillations
are imposed on the background activity by inhibitory feedback in the gamma
range (30-80 Hz). Beats recur at theta rates (3-7 Hz), at which the order
parameter transiently approaches zero and microscopic activity becomes
disordered. After these null spikes, the order parameter resurges and initiates
a frame bearing a mesoscopic spatial pattern of gamma amplitude modulation that
governs the microscopic activity, and that is correlated with behavior. The
brain waves also reveal a spatial pattern of phase modulation in the form of a
cone. Using the formalism of the dissipative many-body model of brain, we
describe the null spikes and the accompanying phase cones as vortices.


title: The Discrete Hilbert Transform for Non-Periodic Signals

abstract:
  This note investigates the size of the guard band for non-periodic discrete
Hilbert transform, which has recently been proposed for data hiding and
security applications. It is shown that a guard band equal to the duration of
the message is sufficient for a variety of analog signals and is, therefore,
likely to be adequate for discrete or digital data.


title: Oscillations of tori in the pseudo-Newtonian potential

abstract:
  Context. The high-frequency quasi-periodic oscillations (HF QPOs) in neutron
star and stellar-mass black hole X-ray binaries may be the result of a
resonance between the radial and vertical epicyclic oscillations in strong
gravity. Aims. In this paper we investigate the resonant coupling between the
epicyclic modes in a torus in a strong gravitational field. Methods. We perform
numerical simulations of axisymmetric constant angular momentum tori in the
pseudo-Newtonian potential. The epicyclic motion is excited by adding a
constant radial velocity to the torus. Results. We verify that slender tori
perform epicyclic motions at the frequencies of free particles, but the
epicyclic frequencies decrease as the tori grow thicker. More importantly, and
in contrast to previous numerical studies, we do not find a coupling between
the radial and vertical epicyclic motions. The appearance of other modes than
the radial epicyclic motion in our simulations is rather due to small numerical
deviations from exact equilibrium in the initial state of our torus.
Conclusions. We find that there is no pressure coupling between the two
axisymmetric epicyclic modes as long as the torus is symmetric with respect to
the equatorial plane. However we also find that there are other modes in the
disc that may be more attractive for explaining the HF QPOs.


title: Three lectures on classical integrable systems and gauge field theories

abstract:
  In these lectures I consider the Hitchin integrable systems and their
relations with the self-duality equations and the twisted super-symmetric
Yang-Mills theory in four dimension follow Hitchin and Kapustin-Witten. I
define the Symplectic Hecke correspondence between different integrable
systems. As an example I consider Elliptic Calogero-Moser system and integrable
Euler-Arnold top on coadjoint orbits of the group GL(N,C) and explain the
Symplectic Hecke correspondence for these systems.


title:
Constraints on the rare tau decays from mu --> e gamma in the
  supersymmetric see-saw model

abstract:
  It is now a firmly established fact that all family lepton numbers are
violated in Nature. In this paper we discuss the implications of this
observation for future searches for rare tau decays in the supersymmetric
see-saw model. Using the two loop renormalization group evolution of the soft
terms and the Yukawa couplings we show that there exists a lower bound on the
rate of the rare process mu --> e gamma of the form BR(mu --> e gamma) > C
BR(tau --> mu gamma) BR(tau --> e gamma), where C is a constant that depends on
supersymmetric parameters. Our only assumption is the absence of cancellations
among the high-energy see-saw parameters. We also discuss the implications of
this bound for future searches for rare tau decays. In particular, for large
regions of the mSUGRA parameter space, we show that present B-factories could
discover either tau --> mu gamma or tau --> e gamma, but not both.


title: A homotopical algebra of graphs related to zeta series

abstract:
  The purpose of this paper is to develop a homotopical algebra for graphs,
relevant to zeta series and spectra of finite graphs. More precisely, we define
a Quillen model structure in a category of graphs (directed and possibly
infinite, with loops and multiple arcs allowed). The weak equivalences for this
model structure are the Acyclics (graph morphisms which preserve cycles). The
cofibrations and fibrations for the model are determined from the class of
Whiskerings (graph morphisms produced by grafting trees). Our model structure
seems to fit well with the importance of acyclic directed graphs in many
applications.
  In addition to the weak factorization systems which form this model
structure, we also describe two Freyd-Kelly factorization systems based on
Folding, Injecting, and Covering graph morphisms.


title: Separating NOF communication complexity classes RP and NP

abstract:
  We provide a non-explicit separation of the number-on-forehead communication
complexity classes RP and NP when the number of players is up to \delta log(n)
for any \delta<1. Recent lower bounds on Set-Disjointness [LS08,CA08] provide
an explicit separation between these classes when the number of players is only
up to o(loglog(n)).


title: The open mapping theorem for regular quaternionic functions

abstract:
  The basic results of a new theory of regular functions of a quaternionic
variable have been recently stated, following an idea of Cullen. In this paper
we prove the minimum modulus principle and the open mapping theorem for regular
functions. The proofs involve some peculiar geometric properties of such
functions which are of independent interest.


title:
Process POVM: A mathematical framework for the description of process
  tomography experiments

abstract:
  In this paper we shall introduce the mathematical framework for the
description of measurements of quantum processes. Using this framework the
process estimation problems can be treated in the similar way as the state
estimation problems, only replacing the concept of positive operator valued
measure (POVM) by the concept of process POVM (PPOVM). In particular, we will
show that any measurement of qudit channels can be described by a collection of
effects (positive operators) defined on two-qudit system. However, the effects
forming a PPOVM are not normalized in the usual sense. We will demonstrate the
usage of this formalism in discrimination problems by showing that perfect
channel discrimination is equivalent to a specific unambiguous state
discrimination.


title:
A novel technique to make Ohmic contact to a buried two-dimensional
  electron gas in a molecular-beam-epitaxy grown $GaAs/Al_{0.3}Ga_{0.7}As$
  heterostructure with Mn $\delta$-doping

abstract:
  We report on the growth and characterization of a new Diluted Magnetic
Semiconductor (DMS) heterostructure that presents a Two-Dimensional Electron
Gas (2DEG) with a carrier density $n \sim 1.08 \times 10^{12} cm^{-2}$ and a
mobility $\mu \sim 600 cm^{2} / (Vs)$ at T $\sim$ 4.2K. As far as we know this
is the highest mobility value reported in the literature for GaMnAs systems. A
novel technique was developed to make Ohmic contact to the buried 2DEG without
destroying the magnetic properties of our crystal.


title:
HST/STIS Optical Transit Transmission Spectra of the hot-Jupiter
  HD209458b

abstract:
  We present the transmission spectra of the hot-Jupiter HD209458b taken with
the Space Telescope Imaging Spectrograph aboard the Hubble Space Telescope. Our
analysis combines data at two resolutions and applies a complete pixel-by-pixel
limb-darkening correction to fully reveal the spectral line shapes of
atmospheric absorption features. Terrestrial-based Na I and H I contamination
are identified which mask the strong exoplanetary absorption signature in the
Na core, which we find reaches total absorption levels of ~0.11% in a 4.4 Ang
band. The Na spectral line profile is characterized by a wide absorption
profile at the lowest absorption depths, and a sharp transition to a narrow
absorption profile at higher absorption values. The transmission spectra also
shows the presence of an additional absorber at ~6,250 Ang, observed at both
medium and low resolutions. We performed various limb-darkening tests,
including using high precision limb-darkening measurements of the sun to
characterize a general trend of Atlas models to slightly overestimate the
amount of limb-darkening at all wavelengths, likely due to the limitations of
the model's one-dimensional nature. We conclude that, despite these
limitations, Atlas models can still successfully model limb-darkening in high
signal-to-noise transits of solar-type stars, like HD209458, to a high level of
precision over the entire optical regime (3,000-10,000 Ang) at transit phases
between 2nd and 3rd contact.


title: Generalization of One of Lie's Theorems

abstract:
  We prove a generalization of one of Lie's Theorems in the context of Lie-like
algebras$^{2-nd}$.


title:
Influence of Non-Uniform Distribution of Acoustic Wavefield Strength on
  Time-Distance Helioseismology Measurements

abstract:
  By analyzing numerically simulated solar oscillation data, we study the
influence of non-uniform distribution of acoustic wave amplitude, acoustic
source strength, and perturbations of the sound speed on the shifts of acoustic
travel times measured by the time-distance helioseismology method. It is found
that for short distances, the contribution to the mean travel time shift caused
by non-uniform distribution of acoustic sources in sunspots may be comparable
to (but smaller than) the contribution from the sound speed perturbation in
sunspots, and that it has the opposite sign to the sound-speed effect. This
effect may cause some underestimation of the negative sound-speed perturbations
in sunspots just below the surface, that was found in previous time-distance
helioseismology inferences. This effect cannot be corrected by artificially
increasing the amplitude of oscillations in sunspots. For large time-distance
annuli, the non-uniform distribution of wavefields does not have significant
effects on the mean travel times, and thus the sound-speed inversion results.
The measured travel time differences, which are used to determine the mass
flows beneath sunspots, can also be systematically shifted by this effect, but
only in an insignificant magnitude.


title:
Non-uniform liquid--crystalline phases of parallel hard rod-shaped
  particles: From ellipsoids to cylinders

abstract:
  In this article we consider systems of parallel hard {\it superellipsoids},
which can be viewed as a possible interpolation between ellipsoids of
revolution and cylinders. Superellipsoids are characterized by an aspect ratio
and an exponent $\alpha$ (shape parameter) which takes care of the geometry,
with $\alpha=1$ corresponding to ellipsoids of revolution, while
$\alpha=\infty$ is the limit of cylinders. It is well known that, while hard
parallel cylinders exhibit nematic, smectic, and solid phases, hard parallel
ellipsoids do not stabilize the smectic phase, the nematic phase transforming
directly into a solid as density is increased. We use computer simulation to
find evidence that for $\alpha\ge\alpha_c$, where $\alpha_c$ is a critical
value which the simulations estimate to be in the interval 1.2--1.3, the
smectic phase is stabilized. This is surprisingly close to the ellipsoidal
case. In addition, we use a density-functional approach, based on the
Parsons--Lee approximation, to describe smectic and columnar ordering. In
combination with a free--volume theory for the crystalline phase, a theoretical
phase diagram is predicted. While some qualitative features, such as the
enhancement of smectic stability for increasing $\alpha$, and the probable
absence of a stable columnar phase, are correct, the precise location of
coexistence densities are quantitatively incorrect.


title:
Early-A stars from IPHAS, and their distribution in and around the Cyg
  OB2 association

abstract:
  Stellar photometry derived from the INT/WFC Photometric H$\alpha$ Survey of
the Northern Galactic Plane (IPHAS) can be used to identify large, reliable
samples of A0-A5 dwarfs. For every A star, so identified, it is also possible
to derive individual reddening and distance estimates, under the assumption
that most selected objects are on or near the main sequence, at a mean absolute
r' magnitude of 1.5 -- 1.6. This study presents the method for obtaining such
samples and shows that the known reddenings and distances to the open clusters
NGC 7510 and NGC 7790 are successfully recovered. A sample of over 1000 A stars
is then obtained from IPHAS data in the magnitude range 13.5 < r' < 20 from the
region of sky including the massive northern OB association Cyg OB2. Analysis
of these data reveals a concentration of ~200 A stars over an area about a
degree across, offset mainly to the south of the known 1--3 Myr old OB stars in
Cyg OB2: their dereddened r' magnitudes fall in the range 11.8 to 12.5. These
are consistent with a ~7 Myr old stellar population at DM = 10.8, or with an
age of ~5 Myr at DM = 11.2. The number of A stars found in this clustering
alone is consistent with a lower limit to the cluster mass of ~10000 M-sun.


title: Superspace formulations of ten-dimensional supergravity

abstract:
  We present a new formulation for N=1, D=10 supergravity in superspace, in
presence of a Lorentz Chern-Simons-form. This formulation entails the following
properties: it furnishes a solution of the Bianchi identities that is
algebraically consistent to all orders in alpha'; at first order it is the
simplest formulation proposed so far, and it is therefore most suitable for an
explicit higher order analysis; it allows a well defined perturbative expansion
in alpha', in which no poltergeist fields appear; it reconciles the two
different classes of first order solutions available in the literature, that
until now appeared physically inequivalent.


title: Gradient NLW on curved background in 4+1 dimensions

abstract:
  We obtain a sharp local well-posedness result for the Gradient
  Nonlinear Wave Equation on a nonsmooth curved background. In the process we
introduce variable coefficient versions of Bourgain's $X^{s,b}$ spaces, and use
a trilinear multiscale wave packet decomposition in order to prove a key
trilinear estimate.


title:
Electron-mediated ferromagnetism and small spin-orbit interaction in a
  molecular-beam-epitaxy grown n-type $GaAs/Al_{0.3}Ga_{0.7}As$ heterostructure
  with Mn $\delta$-doping

abstract:
  We report the first evidence of electron-mediated ferromagnetism in a
molecular-beam-epitaxy (MBE) grown $GaAs/Al_{0.3}Ga_{0.7}As$ heterostructure
with Mn $\delta$-doping. The interaction between the magnetic dopants (Mn) and
the Two-Dimensional Electron Gas (2DEG) realizes magnetic ordering when the
temperature is below the Curie temperature ($T_{C} \sim 1.7K$) and the 2DEG is
brought in close proximity to the Mn layer by gating. The Anomalous Hall Effect
(AHE) contribution to the total Hall resistance is shown to be about three to
four orders of magnitude smaller than in the case of hole-mediated
ferromagnetism indicating the presence of small spin-orbit interaction.


title:
On the endomorphisms of Weyl modules over affine Kac-Moody algebras at
  the critical level

abstract:
  We present an independent short proof of the main result of arXiv:0706.3725
that the algebra of endomorphisms of a Weyl module of critical level is
isomorphic to the algebra of functions on the space of monodromy-free opers on
the disc with regular singularity and residue determined by the highest weight
of the Weyl module. We derive this from the results of arXiv:0712.1183 about
the shift of argument subalgebras.


title: Powerful flares from recoiling black holes in quasars

abstract:
  Mergers of spinning black holes can give recoil velocities from gravitational
radiation up to several thousand km/s. A recoiling supermassive black hole in
an AGN retains the inner part of its accretion disk. Marginally bound material
rejoining the disk around the moving black hole releases a large amount of
energy in shocks in a short time, leading to a flare in thermal soft X-rays
with a luminosity approaching the Eddington limit. Reprocessing of the X-rays
by the infalling material gives strong optical and ultraviolet emission lines
with a distinctive spectrum. Despite the short lifetime of the flare (~10^4
yr), as many as 100 flares may be in play at the present time in QSOs at
redshifts ~ 1 to 3. These flares provide a means to identify high velocity
recoils.


title: On low rank perturbation of matrices

abstract:
  The article is devoted to different aspects of the question "What can be done
with a matrix by low rank perturbation?" It is proved that one can change a
geometrically simple spectrum drastically by a rank 1 permutation, but the
situation is quite different if one restricts oneself to normal matrices. Also,
the Jordan normal form of a perturbed matrix is considered. It is proved that
with respect to rank as a distance all almost unitary matrices are near
unitary.


title: Are complex systems hard to evolve?

abstract:
  Evolutionary complexity is here measured by the number of trials/evaluations
needed for evolving a logical gate in a non-linear medium. Behavioural
complexity of the gates evolved is characterised in terms of cellular automata
behaviour. We speculate that hierarchies of behavioural and evolutionary
complexities are isomorphic up to some degree, subject to substrate specificity
of evolution and the spectrum of evolution parameters.


title:
The evolution of microRNA-regulation in duplicated genes facilitates
  expression divergence

abstract:
  Background: The evolution of microRNA regulation in metazoans is a mysterious
process: MicroRNA sequences are highly conserved among distal organisms, but on
the other hand, there is no evident conservation of their targets. Results: We
study this extensive rewiring of the microRNA regulatory network by analyzing
the evolutionary trajectories of duplicated genes in D. melanogatser. We find
that in general microRNA-targeted genes tend to avoid gene duplication.
However, in cases where gene duplication is evident, we find that the gene that
displays high divergence from the ancestral gene at the sequence level is also
likely to be associated in an opposing manner with the microRNA regulatory
system - if the ancestral gene is a miRNA target then the divergent gene tends
not to be, and vice versa. Conclusions: This suggests that miRNAs not only have
a role in conferring expression robustness, as was suggested by previous works,
but are also an accessible tool in evolving expression divergence.


title:
Rigorous Derivation of the Gross-Pitaevskii Equation with a Large
  Interaction Potential

abstract:
  Consider a system of $N$ bosons in three dimensions interacting via a
repulsive short range pair potential $N^2V(N(x_i-x_j))$, where $\bx=(x_1, >...,
x_N)$ denotes the positions of the particles. Let $H_N$ denote the Hamiltonian
of the system and let $\psi_{N,t}$ be the solution to the Schr\"odinger
equation. Suppose that the initial data $\psi_{N,0}$ satisfies the energy
condition \[ < \psi_{N,0}, H_N \psi_{N,0} > \leq C N >. \] and that the
one-particle density matrix converges to a projection as $N \to \infty$. Then,
we prove that the $k$-particle density matrices of $\psi_{N,t}$ factorize in
the limit $N \to \infty$. Moreover, the one particle orbital wave function
solves the time-dependent Gross-Pitaevskii equation, a cubic non-linear
Schr\"odinger equation with the coupling constant proportional to the
scattering length of the potential $V$. In \cite{ESY}, we proved the same
statement under the condition that the interaction potential $V$ is
sufficiently small; in the present work we develop a new approach that requires
no restriction on the size of the potential.


title:
A Survey of Hydroxyl Toward Supernova Remnants: Evidence for Extended
  1720 MHz Maser Emission

abstract:
  We present the results of GBT observations of all four ground-state hydroxyl
(OH) transitions toward 15 supernova remnants (SNRs) which show OH(1720 MHz)
maser emission. This species of maser is well established as an excellent
tracer of an ongoing interaction between the SNR and dense molecular material.
For the majority of these objects we detect significantly higher flux densities
with a single dish than has been reported with interferometric observations. We
infer that spatially extended, low level maser emission is a common phenomenon
that traces the large-scale interaction in maser-emitting SNRs. Additionally we
use a collisional pumping model to fit the physical conditions under which OH
is excited behind the SNR shock front. We find the observed OH gas associated
with the SNR interaction having columns less than approximately 10^17 per
square cm, temperatures of 20 to 125 K, and densities 10^5 per cubic cm.


title:
Intrinsic and extrinsic noise effects on the phase transition of
  swarming systems and related network models

abstract:
  We analyze order-disorder phase transitions driven by noise that occur in two
kinds of network models closely related to the self-propelled model proposed by
Vicsek et. al. to describe the collective motion of groups of organisms
[\emph{Phys. Rev. Lett.} {\bf 75}:1226 (1995)]. Two different types of noise,
which we call intrinsic and extrinsic, are considered. The intrinsic noise, the
one used by Vicsek et. al. in their original work, is related to the decision
mechanism through which the particles update their positions. In contrast, the
extrinsic noise, later introduced by Gr\'egoire and Chat\'e [\emph{Phys. Rev.
Lett.} {\bf 92}:025702 (2004)], affects the signal that the particles receive
from the environment. The network models presented here can be considered as
the mean-field representation of the self-propelled model. We show analytically
and numerically that, for these two network models, the phase transitions
driven by the intrinsic noise are continuous, whereas the extrinsic noise
produces discontinuous phase transitions. This is true even for the small-world
topology, which induces strong spatial correlations between the network
elements. We also analyze the case where both types of noise are present
simultaneously. In this situation, the phase transition can be continuous or
discontinuous depending upon the amplitude of each type of noise.


title:
Doped AB_2 Hubbard Chain: Spiral, Nagaoka and RVB States, Phase
  Separation and Luttinger Liquid Behavior

abstract:
  We present an extensive numerical study of the Hubbard model on the doped
AB$_2$ chain, both in the weak coupling and the infinite-U limit. Due to the
special unit cell topology, this system displays a rich variety of phases as
function of hole doping ($\delta$) away from half-filling. Near half-filling,
spiral states develop in the weak coupling regime, while Nagaoka itinerant
ferromagnetism is observed in the infinite-U limit. For higher doping the
system phase-separates before reaching a Mott insulating phase of short-range
RVB states at $\delta=1/3$. Moreover, for $\delta>1/3$ we observe a crossover,
which anticipates the Luttinger liquid behavior for $\delta > 2/3$.


title: Deriving Sorting Algorithms

abstract:
  This paper proposes new derivations of three well-known sorting algorithms,
in their functional formulation. The approach we use is based on three main
ingredients: first, the algorithms are derived from a simpler algorithm, i.e.
the specification is already a solution to the problem (in this sense our
derivations are program transformations). Secondly, a mixture of inductive and
coinductive arguments are used in a uniform, algebraic style in our reasoning.
Finally, the approach uses structural invariants so as to strengthen the
equational reasoning with logical arguments that cannot be captured in the
algebraic framework.


title:
Initial Measurements of Black Hole Spin in GX 339-4 from Suzaku
  Spectroscopy

abstract:
  We report on a deep Suzaku observation of the stellar-mass black hole GX
339-4 in outburst. A clear, strong, relativistically-shaped iron emission line
from the inner accretion disk is observed. The broad-band disk reflection
spectrum revealed is one of the most sensitive yet obtained from an accreting
black hole. We fit the Suzaku spectra with a physically-motivated disk
reflection model, blurred by a new relativistic line function in which the
black hole spin parameter is a variable. This procedure yielded a black hole
spin parameter of a = 0.89 +/- 0.04. Joint modeling of these Suzaku spectra and
prior XMM-Newton spectra obtained in two different outburst phases yields a
spin parameter of a = 0.93 +/- 0.01. The degree of consistency between these
results suggests that disk reflection models allow for spin measurements that
are not strongly biased by scattering effects. We suggest that the best value
of the black hole spin parameter is a = 0.93 +/- 0.01 (statistical) +/- 0.04
(systematic). Although preliminary, these results represent the first direct
measurement of non-zero spin in a stellar-mass black hole using relativistic
line modeling.


title:
Genetic selection of neutron star structure matching the X-ray
  observations

abstract:
  Assuming a resonant origin of the quasiperiodic oscillations observed in the
X-ray neutron star binary systems, we apply a genetic algorithm method for
selection of neutron star models. It was suggested that pairs of kilo-Hertz
peaks in the X-ray Fourier power density spectra of some neutron stars reflect
a non-linear resonance between two modes of accretion disk oscillations. In
several specific models, the two modes are related to physically plausible
combinations of Keplerian, vertical and radial frequencies of geodesic orbital
motion. We investigate this concept for a specific neutron star source, a fixed
pair of modes and various neutron star equations of state. Each neutron star
model is characterized by the equation of state (EOS), rotation frequency
($\Omega$) and central energy density ($\rho_\mathrm c$). These determine the
spacetime structure governing geodesic motion and position dependent radial and
vertical epicyclic oscillations related to the stable circular geodesics. When
the parameters of neutron star model are fixed, the two considered modes imply
a frequency-frequency relation which can be compared to the observation in
order to eliminate the unsatisfactory sets (KR,$\rho_\mathrm c, \Omega$, EOS).
For the elimination we use the advanced genetic algorithm. Genetic algorithm
comes out from the method of natural selection when subjects with the best
adaptation to assigned conditions have best chances to survive. The chosen
genetic algorithm with sexual reproduction contains one chromosome with
restricted lifetime, uniform crossing and genes of type 3/3/5. For encryption
of physical description (KR,$\rho_\mathrm c, \Omega$, EOS) into chromosome we
use the Gray code. As a fitness function we use correspondence between the
observed and calculated pairs of eigenfrequencies.


title: Are Aryabhata's and Galilean Relativity Equivalent?

abstract:
  This paper considers the question of whether Aryabhata's direct and indirect
references to relativity of motion are equivalent to Galilean Relativity.
Examining verses fom different sections of the text Aryabhatiya, we show that
there is explicit mention of relativity of space and motion, although there is
no explicit reference to the motion being uniform.


title: Rich, Sturmian, and trapezoidal words

abstract:
  In this paper we explore various interconnections between rich words,
Sturmian words, and trapezoidal words. Rich words, first introduced in
arXiv:0801.1656 by the second and third authors together with J. Justin and S.
Widmer, constitute a new class of finite and infinite words characterized by
having the maximal number of palindromic factors. Every finite Sturmian word is
rich, but not conversely. Trapezoidal words were first introduced by the first
author in studying the behavior of the subword complexity of finite Sturmian
words. Unfortunately this property does not characterize finite Sturmian words.
In this note we show that the only trapezoidal palindromes are Sturmian. More
generally we show that Sturmian palindromes can be characterized either in
terms of their subword complexity (the trapezoidal property) or in terms of
their palindromic complexity. We also obtain a similar characterization of rich
palindromes in terms of a relation between palindromic complexity and subword
complexity.


title:
Galaxy Evolution in Dense Environments: Properties of Interacting
  Galaxies in the A901/02 Supercluster

abstract:
  We present a study of galaxies in the STAGES survey of the Abell 901/902
supercluster at z~0.165, based on HST ACS F606W, COMBO-17, Spitzer 24um,
XMM-Newton X-ray, and gravitational lensing maps. We characterize galaxies with
strong, externally-triggered morphological distortions and normal, relatively
undisturbed galaxies, using visual classification and quantitative CAS
parameters. We compare normal and distorted galaxies in terms of their
frequency, distribution within the cluster, star formation properties, and
relationship to dark matter (DM) or surface mass density, and intra-cluster
medium (ICM) density. We report here our preliminary results.


title:
Search for Pair Production of Scalar Top Quarks Decaying to a tau Lepton
  and a b Quark in ppbar Collisions at sqrt{s}=1.96 TeV

abstract:
  We search for pair production of supersymmetric top quarks (~t_1), followed
by R-parity violating decay ~t_1 -> tau b with a branching ratio beta, using
322 pb^-1 of ppbar collisions at sqrt{s}=1.96 TeV collected by the CDF II
detector at Fermilab. Two candidate events pass our final selection criteria,
consistent with the standard model expectation. We set upper limits on the
cross section sigma(~t_1 ~tbar_1)*beta^2 as a function of the stop mass
m(~t_1). Assuming beta=1, we set a 95% confidence level limit m(~t_1)>153
GeV/c^2. The limits are also applicable to the case of a third generation
scalar leptoquark (LQ_3) decaying LQ_3 -> tau b.


title: Directive words of episturmian words: equivalences and normalization

abstract:
  Episturmian morphisms constitute a powerful tool to study episturmian words.
Indeed, any episturmian word can be infinitely decomposed over the set of pure
episturmian morphisms. Thus, an episturmian word can be defined by one of its
morphic decompositions or, equivalently, by a certain directive word. Here we
characterize pairs of words directing a common episturmian word. We also
propose a way to uniquely define any episturmian word through a normalization
of its directive words. As a consequence of these results, we characterize
episturmian words having a unique directive word.


title:
Polygones de Newton de certaines sommes de caract\`eres et s\'eries de
  Poincar\'e

abstract:
  In this paper, we shall precise the asymptotic behaviour of Newton polygons
of $L$ functions associated to character sums, coming from some $n$ variable
Laurent polynomials. In order to do this, we use the free sum on convex
polytopes. This operation allows the determination of the limit of generic
Newton polygons for the sum $\Delta=\Delta_1\oplus \Delta_2$ when we know the
limit of generic Newton polygons for each factor. To our knowledge, these are
the first results concerning the asymptotic behaviour of Newton polygons for
multivariable polynomials.


title: PGA Tour Scores as a Gaussian Random Variable

abstract:
  In this paper it is demonstrated that the scoring at each PGA Tour stroke
play event can be reasonably modeled as a Gaussian random variable. All 46
stroke play events in the 2007 season are analyzed. The distributions of scores
are favorably compared with a Gaussian distribution using the
Kolmogorov-Smirnov test. This observation suggests performance tracking on the
PGA tour should be done in terms of the z-score, calculated by subtracting the
mean from the raw score and dividing by the standard deviation. This
methodology measures performance relative to the field of competitors,
independent of the venue, and in terms of a statistic that has quantitative
meaning. Several examples of the use of this scoring methodology are provided,
including a calculation of the probability that Tiger Woods will break Byron
Nelson's record of eleven consecutive PGA Tour victories.


title: On logical gates in precipitating medium: cellular automaton model

abstract:
  We study a two-dimensional semi-totalistic binary cell-state cellular
automaton, which imitates a reversible precipitation in an abstract chemical
medium. The systems exhibits a non-trivial growth and nucleation. We
demonstrate how basic computational operation can be realized in the system
when the propagation of the growing patterns is self-restricted by stationary
localizations. We show that precipitating patterns of different morphology
compete between each other and thus implement serial and non-serial logical
gates.


title: Incomplete quantum process tomography and principle of maximal entropy

abstract:
  The main goal of this paper is to extend and apply the principle of maximum
entropy (MaxEnt) to incomplete quantum process estimation tasks. We will define
a so-called process entropy function being the von Neumann entropy of the state
associated with the quantum process via Choi-Jamiolkowski isomorphism. It will
be shown that an arbitrary process estimation experiment can be reformulated in
a unified framework and MaxEnt principle can be consistently exploited. We will
argue that the suggested choice for the process entropy satisfies natural list
of properties and it reduces to the state MaxEnt principle, if applied to
preparator devices.