title:
Defining the integers in large rings of number fields using one
  universal quantifier

abstract:
  Julia Robinson has given a first-order definition of the rational integers
$\mathbb Z$ in the rational numbers $\mathbb Q$ by a formula $(\forall \exists
\forall \exists)(F=0)$ where the $\forall$-quantifiers run over a total of 8
variables, and where F is a polynomial.
  We show that for a large class of number fields, not including $\mathbb Q$,
for every $\epsilon>0$, there exists a set of primes $\cal S$ of natural
density exceeding $1-\epsilon$, such that $\mathbb Z$ can be defined as a
subset of the ``large'' subring $$\{x \in K : \ord_{\mathfrak p}x >0, \forall
\mathfrak p \not \in \cal S \}$$ of K by a formula of the form $(\exists
\forall \exists)(F=0)$ where there is only one $\forall$-quantifier, and where
F is a polynomial.


title: Annihilation of the electron-positron pairs in polyelectrons

abstract:
  This paper has been withdrawn due to disagreement of suggested results and
methods between authors.


title: Chandra detection of diffuse hot gas in and around the M31 bulge

abstract:
  We report the detection of diffuse hot gas in M31, using archival Chandra
observations which allow us to map out a 30' by 30' field (covering a
galactocentric radius up to 4.5 kpc) and to detect sources in the galaxy down
to a 0.5-8 keV luminosity limit of ~10^35 ergs/s. We estimate the remaining
stellar contribution from fainter X-ray sources (primarily cataclysmic
variables and coronally active binaries), assuming that they spatially follow
the stellar distribution. Indeed, the near-IR K-band light of the galaxy
closely traces the 2-8 keV unresolved X-rays, indicating a collective stellar
X-ray emissivity consistent with those determined for the Galactic ridge and
M32, whereas the amount of the 0.5-2 keV unresolved emission is significantly
greater than the expected stellar contribution, especially within a
galactocentric radius of ~2 kpc. Morphologically, this soft X-ray excess
appears substantially rounder than the bulge as seen in K-band and is elongated
approximately along the minor-axis at large radii. The excess thus most likely
represents the emission of diffuse hot gas in and around the galactic bulge.
Furthermore, the near side of the M31 disk casts an apparent shadow against the
soft X-ray excess, indicating that the hot gas extends to at least 2.5 kpc from
the galactic plane. We briefly discuss the implications of these results on the
energy balance in the M31 bulge and on understanding the large-scale soft X-ray
enhancement observed toward the inner region of our own Galaxy.


title: Non-stable K-theory and extremally rich C*-algebras

abstract:
  We consider the properties weak cancellation, K_1-surjectivity, good index
theory, and K_1-injectivity for the class of extremally rich C*-algebras, and
for the smaller class of isometrically rich C*-algebras. We establish all four
properties for isometrically rich C*-algebras and for extremally rich
C*-algebras that are either purely infinite or of real rank zero,
K_1-injectivity in the real rank zero case following from a prior result of H.
Lin. We also show that weak cancellation implies the other properties for
extremally rich C*-algebras and that the class of extremally rich C*-algebras
with weak cancellation is closed under extensions. Moreover, we consider
analogous properties which replace the group K_1(A) with the extremal K-set
K_e(A) as well as two versions of K_0-surjectivity.


title: Feynman's Integral is About Mutually Unbiased Bases

abstract:
  The Feynman integral can be seen as an attempt to relate, under certain
circumstances, the quantum-information-theoretic separateness of mutually
unbiased bases to causal proximity of the measuring processes.


title: Constraint from D - anti-D Mixing in Left-Right Symmetric Models

abstract:
  We study the constraint arising from the recently observed D - anti-D mixing
in the context of supersymmetric models with left-right symmetry. In these
models, the supersymmetric contributions in the mixing amplitudes of D -
anti-D, K - anti-K and B - anti-B are all correlated. We compare the constraint
from the D - anti-D mixing with the K - anti-K mixing and find that the D -
anti-D mixing constrains the maximal supersymmetric contribution to the B_s -
anti-B_s mixing amplitude. The maximal supersymmetric contribution can allow a
large CP phase of B_s - anti-B_s mixing which agrees with the recent
measurement of the CP asymmetry of B_s -> J/psi phi decay.


title: Transport in Graphene p-n Junctions in Magnetic Field

abstract:
  Ballistic transport in graphene p-n junctions in the presence of magnetic
field exhibits two distinct regimes: At low fields, transport is partially
suppressed by the field. When the field exceeds a certain critical value, the
junction is pinched off by the Landau level formation. Transmission and
conductance are found in the entire range of fields using Lorentz boost and
mapping to the Landau-Zener problem. We show that perfect transmission occurs
at a field-dependent collimation angle, indicating that the chiral dynamics of
massless Dirac fermions persists at a finite magnetic field. A current switch,
utilizing field-tunable collimation angle, is proposed. With a generalization
of the developed approach we study transmission through p-n junctions in
graphene bilayer.


title:
Path Integral Approach for for Quantum Motion on Spaces of Non-constant
  Curvature According to Koenigs: Three Dimensions

abstract:
  In this contribution a path integral approach for the quantum motion on
three-dimensional spaces according to Koenigs, for short``Koenigs-Spaces'', is
discussed. Their construction is simple: One takes a Hamiltonian from
three-dimensional flat space and divides it by a three-dimensional
superintegrable potential. Such superintegrable potentials will be the
isotropic singular oscillator, the Holt-potential, the Coulomb potential, or
two centrifugal potentials, respectively. In all cases a non-trivial space of
non-constant curvature is generated. In order to obtain a proper quantum theory
a curvature term has to be incorporated into the quantum Hamiltonian. For
possible bound-state solutions we find equations up to twelfth order in the
energy E.


title: Dynamics around supermassive black holes

abstract:
  The dynamics of galactic nuclei reflects the presence of supermassive black
holes (SBHs) in many ways. Single SBHs act as sinks, destroying a mass in stars
equal to their own mass in roughly one relaxation time and forcing nuclei to
expand. Formation of binary SBHs displaces a mass in stars roughly equal to the
binary mass, creating low-density cores and ejecting hyper-velocity stars.
Gravitational radiation recoil can eject coalescing binary SBHs from nuclei,
resulting in offset SBHs and lopsided cores. We review recent work on these
mechanisms and discuss the observable consequences.


title:
Commensurate lock-in and incommensurate supersolid phases of hardcore
  bosons on anisotropic triangular lattices

abstract:
  We investigate the interplay between commensurate lock-in and incommensurate
supersolid phases of the hardcore bosons at half-filling with anisotropic
nearest-neighbor hopping and repulsive interactions on triangular lattice. We
use numerical quantum and variational Monte Carlo as well as analytical
Schwinger boson mean-field analysis to establish the ground states and phase
diagram. It is shown that, for finite size systems, there exist a series of
jumps between different supersolid phases as the anisotropy parameter is
changed. The density ordering wavevectors are locked to commensurate values and
jump between adjacent supersolids. In the thermodynamic limit, however, the
magnitude of these jumps vanishes leading to a continuous set of novel
incommensurate supersoild phases.


title:
A nonlinear theory of non-stationary low Mach number channel flows of
  freely cooling nearly elastic granular gases

abstract:
  We use hydrodynamics to investigate non-stationary channel flows of freely
cooling dilute granular gases. We focus on the regime where the sound travel
time through the channel is much shorter than the characteristic cooling time
of the gas. As a result, the gas pressure rapidly becomes almost homogeneous,
while the typical Mach number of the flow drops well below unity. Eliminating
the acoustic modes, we reduce the hydrodynamic equations to a single nonlinear
and nonlocal equation of a reaction-diffusion type in Lagrangian coordinates.
This equation describes a broad class of channel flows and, in particular, can
follow the development of the clustering instability from a weakly perturbed
homogeneous cooling state to strongly nonlinear states. If the heat diffusion
is neglected, the reduced equation is exactly soluble, and the solution
develops a finite-time density blowup. The heat diffusion, however, becomes
important near the attempted singularity. It arrests the density blowup and
brings about novel inhomogeneous cooling states (ICSs) of the gas, where the
pressure continues to decay with time, while the density profile becomes
time-independent. Both the density profile of an ICS, and the characteristic
relaxation time towards it are determined by a single dimensionless parameter
that describes the relative role of the inelastic energy loss and heat
diffusion. At large values of this parameter, the intermediate cooling dynamics
proceeds as a competition between low-density regions of the gas. This
competition resembles Ostwald ripening: only one hole survives at the end.


title: Chemistry and cooling in metal-free and metal-poor gas

abstract:
  I summarize four of the most important areas of uncertainty in the study of
the chemistry and cooling of gas with zero or very low metallicity. These are:
i) the importance and effects of HD cooling in primordial gas; ii) the
importance of metal-line and dust cooling in low metallicity gas; iii) the
impact of the large uncertainties that exist in the rate coefficients of
several key reactions involved in the formation of H2; and iv) the
effectiveness of grain surface chemistry at high redshifts.


title: The Tidal Evolution of Local Group Dwarf Spheroidals

abstract:
  (Abridged) We use N-body simulations to study the evolution of dwarf
spheroidal galaxies (dSphs) driven by galactic tides. We adopt a
cosmologically-motivated model where dSphs are approximated by a King model
embedded within an NFW halo. We find that these NFW-embedded King models are
extraordinarily resilient to tides; the stellar density profile still resembles
a King model even after losing more than 99% of the stars. As tides strip the
galaxy, the stellar luminosity, velocity dispersion, central surface
brightness, and core radius decrease monotonically. Remarkably, we find that
the evolution of these parameters is solely controlled by the total amount of
mass lost from within the luminous radius. Of all parameters, the core radius
is the least affected: after losing 99% of the stars, R_c decreases by just a
factor of ~2. Interestingly, tides tend to make dSphs more dark-matter
dominated because the tightly bound central dark matter ``cusp'' is more
resilient to disruption than the ``cored'' King profile. We examine whether the
extremely large M/L ratios of the newly-discovered ultra-faint dSphs might have
been caused by tidal stripping of once brighter systems. Although dSph tidal
evolutionary tracks parallel the observed scaling relations in the
luminosity-radius plane, they predict too steep a change in velocity dispersion
compared with the observational estimates hitherto reported in the literature.
The ultra-faint dwarfs are thus unlikely to be the tidal remnants of systems
like Fornax, Draco, or Sagittarius. Despite spanning four decades in
luminosity, dSphs appear to inhabit halos of comparable peak circular velocity,
lending support to scenarios that envision dwarf spheroidals as able to form
only in halos above a certain mass threshold.


title:
The Fourth Positive System of Carbon Monoxide in the Hubble Space
  Telescope Spectra of Comets

abstract:
  The rich structure of the Fourth Positive System (A-X) of carbon monoxide
accounts for many of the spectral features seen in long slit HST-STIS
observations of comets 153P/Ikeya-Zhang, C/2001 Q4 (NEAT), and C/2000 WM1
(LINEAR), as well as in the HST-GHRS spectrum of comet C/1996 B2 Hyakutake. A
detailed CO fluorescence model is developed to derive the CO abundances in
these comets by simultaneously fitting all of the observed A-X bands. The model
includes the latest values for the oscillator strengths and state parameters,
and accounts for optical depth effects due to line overlap and self-absorption.
The model fits yield radial profiles of CO column density that are consistent
with a predominantly native source for all the comets observed by STIS. The
derived CO abundances relative to water in these comets span a wide range, from
0.44% for C/2000 WM1 (LINEAR), 7.2% for 153P/Ikeya-Zhang, 8.8% for C/2001 Q4
(NEAT) to 20.9% for C/1996 B2 (Hyakutake). The subtraction of the CO spectral
features using this model leads to the first identification of a molecular
hydrogen line pumped by solar HI Lyman-beta longward of 1200A in the spectrum
of comet 153P/Ikeya-Zhang. (Abridged)


title: Keck Hires Spectroscopy of Candidate Post T Tauri Stars

abstract:
  We use high-signal-to-noise ($\sim$150-450), high resolution
($R{\sim}45,000$) Keck HIRES spectroscopy of 13 candidate post T Tauri stars to
derive basic physical parameters, lithium abundances and radial velocities. We
place our stars in the M$_v$-T$_{eff}$ plane for use in determining approximate
ages from pre-main sequence isochrones, and confirm these using three relative
age indicators in our analysis: Li abundances, chromospheric emission and the
kinematic {\it U-V} plane. Using the three age criteria we identify 5 stars
(HIP 54529, HIP 62758, HIP 63322, HIP 74045, and HIP 104864) as probable post T
Tauri stars with ages between 10 and 100 Myr. We confirm HIP 54529 as an SB2
and HIP 63322 as an SB1 star. We also examine irregular photometric variability
of PTTs using the {\it HIPPARCOS} photometry annex. Two of our PTT stars
exhibit near-IR excesses compared to Kurucz model flux; while recent work
suggests classical T Tauri stars evince similar {\it JHK} excesses presumably
indicative of non-photospheric (disk) emission, our results may be illusory
artifacts of the chosen {\it I}-band normalization. Near-IR excesses we see in
a literature-based sample of PTTs appear to be artifacts of previous spectral
type-based $T_{\rm eff}$ values. Indeed, comparison of the homology of their
observed and model photospheric SED's suggests that photometric temperatures
are more reliable than temperatures based on spectral standards for the cooler
temperature ranges of the stars in this sample. We conclude that our age
oriented analysis is a robust means to select samples of nearby, young,
isolated post T Tauri stars that otherwise masquerade as normal field stars.


title: Role of disorder in the size-scaling of material strength

abstract:
  We study the sample size dependence of the strength of disordered materials
with a flaw, by numerical simulations of lattice models for fracture. We find a
crossover between a regime controlled by the fluctuations due to disorder and
another controlled by stress-concentrations, ruled by continuum fracture
mechanics. The results are formulated in terms of a scaling law involving a
statistical fracture process zone. Its existence and scaling properties are
only revealed by sampling over many configurations of the disorder. The scaling
law is in good agreement with experimental results obtained from notched paper
samples.


title: Spin orbit interaction and zitterbewegung in symmetric wells

abstract:
  Recently, we have introduced a novel inter-subband-induced spin-orbit (s-o)
coupling [Phys. Rev. Lett. 99, 076603 (2007); cond-mat/0607218] arising in
\textit{symmetric} wells with at least two subbands. This new s-o coupling
gives rise to an usual zitterbewegung -- i.e. the semiconductor analog to the
relativistic trembling motion of electrons -- with cycloidal motion without
magnetic fields. Here we complement these findings by explicitly deriving
expressions for the corresponding zitterbewegung in spin space.


title: The Molonglo Galactic Plane Survey (MGPS-2): Compact Source Catalogue

abstract:
  We present the first data release from the second epoch Molonglo Galactic
Plane Survey (MGPS-2). MGPS-2 was carried out with the Molonglo Observatory
Synthesis Telescope at a frequency of 843 MHz and with a restoring beam of 45
arcsec x 45 arcsec cosec(dec), making it the highest resolution large scale
radio survey of the southern Galactic plane. It covers the range |b| < 10 deg
and 245 deg < l < 365 deg and is the Galactic counterpart to the Sydney
University Molonglo Sky Survey (SUMSS) which covers the whole southern sky with
dec <= -30 deg (|b| > 10 deg).
  In this paper we present the MGPS-2 compact source catalogue. The catalogue
has 48,850 sources above a limiting peak brightness of 10 mJy/beam. Positions
in the catalogue are accurate to 1 arcsec - 2 arcsec. A full catalogue
including extended sources is in preparation. We have carried out an analysis
of the compact source density across the Galactic plane and find that the
source density is not statistically higher than the density expected from the
extragalactic source density alone.
  We also present version 2.0 of the SUMSS image data and catalogue which are
now available online. The data consists of 629 4.3 deg x 4.3 deg mosaic images
covering the 8100 deg^2 of sky with dec <= -30 deg and |b| > 10 deg. The
catalogue contains 210,412 radio sources to a limiting peak brightness of 6
mJy/beam at dec <= -50 deg and 10 mJy/beam at dec > -50 deg. We describe the
updates and improvements made to the SUMSS cataloguing process.


title: Role of CuO chains in vortex core structure in YBa2Cu3O{7-delta}

abstract:
  The Bogoliubov-deGennes equations are solved for a proximity model for
YBa_2Cu_3O_{7-\delta} in a magnetic field. The model explicitly includes the
effects of the one-dimensional CuO chains, whose influence on the vortex core
structure is studied. The rapid vortex core contraction as a function of field
which is seen experimentally at low magnetic fields is naturally explained by
the presence of the chains.


title: Brane Decay and Defect Formation

abstract:
  Topological defects are generically expected to form in models of brane
inflation. Brane-anti-brane annihilation provides a way to gracefully end
inflation, and the dynamics of the tachyon field results in defect formation.
The formation of defects has been studied mainly from the brane world-volume
point of view, but the defects are themselves lower-dimensional branes, and as
a result they couple to bulk fields. To investigate the impact of bulk fields
on brane defect formation, we construct a toy model that captures the essential
features of the tachyon condensation with bulk fields. In this toy model, we
study the structure of defects and simulate their formation and evolution on a
lattice. We find that while bulk fields do not have a significant effect on
defect formation, they drastically influence the subsequent evolution of the
defects, as they re-introduce long-range interactions between them.


title: Effect of Disorder and Notches on Crack Roughness

abstract:
  We analyze the effect of disorder and notches on crack roughness in two
dimensions. Our simulation results based on large system sizes and extensive
statistical sampling indicate that the crack surface exhibits a universal local
roughness of $\zeta_{loc} = 0.71$ and is independent of the initial notch size
and disorder in breaking thresholds. The global roughness exponent scales as
$\zeta = 0.87$ and is also independent of material disorder. Furthermore, we
note that the statistical distribution of crack profile height fluctuations is
also independent of material disorder and is described by a Gaussian
distribution, albeit deviations are observed in the tails.


title:
Rectification of Swimming Bacteria and Self Driven Particle Systems by
  Arrays of Asymmetric Barriers

abstract:
  We show that the recent experimental observation of the rectification of
swimming bacteria in a system with an array of asymmetric barriers occurs due
to the ballistic component of the bacteria trajectories introduced by the
bacterial "motor." Each bacteria selects a random direction for motion and then
moves in this direction for a fixed period of time before randomly changing its
orientation and moving in a new direction. In the limit where the bacteria
undergo only Brownian motion, rectification by the barriers does not occur. We
also examine the effects of steric interactions between the bacteria and
observe a clogging effect upon increasing the bacteria density.


title: One loop superstring effective actions and N=8 supergravity

abstract:
  In a previous article we have shown the existence of a new independent R^4
term, at one loop, in the type IIA and heterotic effective actions, after
reduction to four dimensions, besides the usual square of the Bel-Robinson
tensor. It had been shown that such a term could not be directly
supersymmetrized, but we showed that was possible after coupling to a scalar
chiral multiplet. In this article we study the extended (N=8)
supersymmetrization of this term, where no other coupling can be taken. We show
that such supersymmetrization cannot be achieved at the linearized level. This
is in conflict with the theory one gets after toroidal compactification of type
II superstrings being N=8 supersymmetric. We interpret this result in face of
the recent claim that perturbative supergravity cannot be decoupled from string
theory in d>=4, and N=8, d=4 supergravity is in the swampland.


title:
CompostBin: A DNA composition-based algorithm for binning environmental
  shotgun reads

abstract:
  A major hindrance to studies of microbial diversity has been that the vast
majority of microbes cannot be cultured in the laboratory and thus are not
amenable to traditional methods of characterization. Environmental shotgun
sequencing (ESS) overcomes this hurdle by sequencing the DNA from the organisms
present in a microbial community. The interpretation of this metagenomic data
can be greatly facilitated by associating every sequence read with its source
organism. We report the development of CompostBin, a DNA composition-based
algorithm for analyzing metagenomic sequence reads and distributing them into
taxon-specific bins. Unlike previous methods that seek to bin assembled contigs
and often require training on known reference genomes, CompostBin has the
ability to accurately bin raw sequence reads without need for assembly or
training. It applies principal component analysis to project the data into an
informative lower-dimensional space, and then uses the normalized cut
clustering algorithm on this filtered data set to classify sequences into
taxon-specific bins. We demonstrate the algorithm's accuracy on a variety of
simulated data sets and on one metagenomic data set with known species
assignments. CompostBin is a work in progress, with several refinements of the
algorithm planned for the future.


title: A multicolor near-infrared study of the dwarf nova IP Peg

abstract:
  We report the analysis of $JHK_{s}$ light curves of the eclipsing dwarf nova
IP Peg in quiescence. The light curves are dominated by the ellipsoidal
variation of the mass-donor star, with additional contributions from the
accretion disc and anisotropic emission from the bright spot. A secondary
eclipse is visible in the $J$ and $H$ light curves, with 2% and 3% of the flux
disappearing at minimum light, respectively. We modeled the observed
ellipsoidal variation of the secondary star (including possible illumination
effects on its inner face) to find a mass ratio of $q = 0.42$ and an
inclination of $i = 84.5^{o} $, consistent in the three bands within the
uncertainties. Illumination effects are negligible. The secondary is
responsible for 83%, 84% and 88% of the flux in $J$, $H$ and $K_{s}$,
respectively. We fitted a black body spectrum to the $JHK_{s}$ fluxes of the
secondary star to find a temperature of $T_{bb} = 3100\pm500 K$ and a distance
of $d=115\pm30$ pc to the system. We subtracted the contribution of the
secondary star and applied 3-D eclipse mapping techniques to the resulting
light curves to map the surface brightness of a disc with half-opening angle
$\alpha$ and a circular rim at the radius of the bright spot. The eclipse maps
show enhanced emission along the stream trajectory ahead of the bright spot
position, providing evidence of gas stream overflow. The inferred radial
brightness-temperature distribution in the disc is flat for $R < 0.3R_{L1}$
with temperatures $\simeq 3500K$ and colors consistent with those of cool
opaque radiators.


title: Determining Spins of Metastable Sleptons at the Large Hadron Collider

abstract:
  We investigate models in minimal supergravity parameter space which contain
metastable sleptons. We find the luminosity required to determine the slepton
spin in these scenarios, and apply our analysis to two benchmark models. We
show that the spin of the slepton in one of the benchmark models can be
determined with less than 30 fb$^{-1}$ of data, while the slepton spin in the
other model can be determined with roughly 40 fb$^{-1}$ of data. We show how
our analysis can be applied to other models, and give an estimate of the
luminosity needed for a spin determination as a function of slepton mass. This
analysis can be used to distinguish supersymmetry and extra dimensions.


title: Orbital Instabilities in a Triaxial Cusp Potential

abstract:
  This paper constructs an analytic form for a triaxial potential that
describes the dynamics of a wide variety of astrophysical systems, including
the inner portions of dark matter halos, the central regions of galactic
bulges, and young embedded star clusters. Specifically, this potential results
from a density profile of the form $\rho (m) \propto m^{-1}$, where the radial
coordinate is generalized to triaxial form so that $m^2 = x^2/a^2 + y^2/b^2 +
z^2/c^2 $. Using the resulting analytic form of the potential, and the
corresponding force laws, we construct orbit solutions and show that a robust
orbit instability exists in these systems. For orbits initially confined to any
of the three principal planes, the motion in the perpendicular direction can be
unstable. We discuss the range of parameter space for which these orbits are
unstable, find the growth rates and saturation levels of the instability, and
develop a set of analytic model equations that elucidate the essential physics
of the instability mechanism. This orbit instability has a large number of
astrophysical implications and applications, including understanding the
formation of dark matter halos, the structure of galactic bulges, the survival
of tidal streams, and the early evolution of embedded star clusters.


title: Spontaneous symmetry breaking in amnestically induced persistence

abstract:
  We investigate a recently proposed non-Markovian random walk model
characterized by loss of memories of the recent past and amnestically induced
persistence. We report numerical and analytical results showing the complete
phase diagram, consisting of 4 phases, for this system: (i) classical
nonpersistence, (ii) classical persistence (iii) log-periodic nonpersistence
and (iv) log-periodic persistence driven by negative feedback. The first two
phases possess continuous scale invariance symmetry, however log-periodicity
breaks this symmetry. Instead, log-periodic motion satisfies discrete scale
invariance symmetry, with complex rather than real fractal dimensions. We find
for log-periodic persistence evidence not only of statistical but also of
geometric self-similarity.


title:
Computer simulations on the sympatric speciation modes for the Midas
  cichlid species complex

abstract:
  Cichlid fishes are one of the best model system for the study of evolution of
the species. Inspired by them, in this paper we simulated the splitting of a
single species into two separate ones via random mutations, with both
populations living together in sympatry, sharing the same habitat. We study the
ecological, mating and genetic conditions needed to reproduce the
polychromatism and polymorphism of three species of the Midas Cichlid species
complex. Our results show two scenarios for the A. Citrinellus speciation
process, one with and the other without disruptive natural selection. In the
first scenario, the ecological and genetic conditions are sufficient to create
two new species, while in the second the mating and genetic conditions must be
synchronized in order to control the velocity of genetic drift.


title: Detecting a unique EBL signature with TeV gamma rays

abstract:
  We discuss prospects for detecting a spectral break in gamma-ray spectra of
blazars due to the extragalactic background light (EBL) density falling off
between the near and mid-IR. A measurable spectral change in the TeV spectra at
1 TeV could arise from a rapid or slow drop in the EBL density above ~1 micron.
This effect is mediated by the ratio of the near to mid-IR density of EBL. A
detection of such a spectral feature could become a clear signature of EBL
absorption. A non-detection would give a strong observational constraint to the
shape of the EBL spectrum. We present calculations estimating the sensitivity
of TeV telescopes for detecting such a break for blazar observations at
different redshifts.


title: Weak subintegral closure of ideals

abstract:
  We describe some basic facts about the weak subintegral closure of ideals in
both the algebraic and complex-analytic settings. We focus on the analogy
between results on the integral closure of ideals and modules and the weak
subintegral closure of an ideal. We start by giving a geometric interpretation
of the Reid-Roberts-Singh criterion for when an element is weakly subintegral
over a subring. We give new characterizations of the weak subintegral closure
of an ideal. We associate with an ideal $I$ of a ring $A$ an ideal $I_>$, which
consists of all elements of $A$ such that $v(a)>v(I)$, for all Rees valuations
$v$ of $I$. The ideal $I_>$ plays an important role in conditions from
stratification theory such as Whitney's condition A and Thom's condition $A_f$
and is contained in every reduction of $I$. We close with a valuative criterion
for when an element is in the weak subintegral closure of an ideal. For this,
we introduce a new closure operation for a pair of modules, which we call
relative closure.


title: Rapidity gap survival in the black-disk regime

abstract:
  We summarize how the approach to the black-disk regime (BDR) of strong
interactions at TeV energies influences rapidity gap survival in exclusive hard
diffraction pp -> p + H + p (H = dijet, Qbar-Q, Higgs). Employing a recently
developed partonic description of such processes, we discuss (a) the
suppression of diffraction at small impact parameters by soft spectator
interactions in the BDR; (b) further suppression by inelastic interactions of
hard spectator partons in the BDR; (c) correlations between hard and soft
interactions. Hard spectator interactions substantially reduce the rapidity gap
survival probability at LHC energies compared to previously reported estimates.


title: On the generalised Selberg integral of Richards and Zheng

abstract:
  In a recent paper Richards and Zheng compute the determinant of a matrix
whose entries are given by beta-type integrals, thereby generalising an earlier
result by Dixon and Varchenko. They then use their result to obtain a
generalisation of the famous Selberg integral.
  In this note we point out that the Selberg-generalisation of Richards and
Zheng is a special case of an integral over Jack polynomials due to Kadell. We
then show how an integral formula for Jack polynomials of Okounkov and
Olshanski may be applied to prove Kadell's integral along the lines of Richards
and Zheng.


title: Plasmonic Bragg Reflectors for Subwavelength Hole Arrays in a Metal Film

abstract:
  We present plasmonic Bragg reflectors for increasing the extraordinary
optical transmission through periodic arrays of subwavelength apertures in a
metal film. The increase in transmission arises by preventing loss at the edges
of the array. The plasmonic Bragg reflectors have periodicity of half the usual
array's periodicity. Nano-hole arrays flanked thus by reflectors exchibited
double the transmission as compared to the arrays without reflectors. These
structures may also be used to isolate devices in plasmonic integrated
circuits.


title: The reddest ISO-2MASS quasar

abstract:
  In the course of the NIR/MIR AGN search combining the 6.7 mu ISOCAM Parallel
Survey and 2MASS we have discovered 24 type-1 quasars about a third of which
are too red to be discriminated by optical/UV search techniques. Here we report
on a detailed case study of the reddest type-1 quasar of our sample (J2341) at
redshift z=0.236 with M_K=-25.8 and J-K=1.95. We performed spectroscopy in the
optical with VLT/FORS1 and in the MIR with Spitzer as well as NIR imaging with
ISPI at CTIO. The optical and NIR observations reveal a star forming
emission-line galaxy at the same redshift as the quasar with a projected linear
separation of 1.8 arcsec (6.7 kpc). The quasar and its companion are embedded
in diffuse extended continuum emission. Compared with its companion the quasar
exhibits redder optical-NIR colours, which we attribute to hot nuclear dust.
The MIR spectrum shows only few emission lines superimposed on a power-law
spectral energy distribution. However, the lack of strong FIR emission suggests
that our potentially interacting object contains much less gas and dust and is
in a stage different from dust reddened ULIRG-AGN like Mrk 231. The optical
spectrum shows signatures for reddening in the emission-lines and no
post-starburst stellar population is detected in the host galaxy of the quasar.
The optical continuum emission of the active nucleus appears absorbed and
diluted. Even the combination of absorption and host dilution is not able to
match J2341 with standard quasar templates. While the BLR shows only a rather
moderate absorption of E_(B-V)=0.3, the continuum shorter than 4500 AA requires
strong obscuration with E_(B-V)=0.7, exceeding the constraints from the low
upper limit on the 9.7 mu silicate absorption. This leads us to conclude that
the continuum of J2341 is intrinsically redder than that of typical quasars.


title: Rogers-Szego polynomials and Hall-Littlewood symmetric functions

abstract:
  We use Rogers-Szego polynomials to unify some well-known identities for
Hall-Littlewood symmetric functions due to Macdonald and Kawanaka.


title:
Cohen-Macaulay, Shellable and unmixed clutters with a perfect matching
  of K\"onig type

abstract:
  Let $\mathcal{C}$ be a clutter with a perfect matching $e_1,...,e_g$ of
K\"onig type and let $\Delta_\mathcal{C}$ be the Stanley-Reisner complex of the
edge ideal of $\mathcal{C}$. If all c-minors of $\mathcal{C}$ have a free
vertex and $\mathcal{C}$ is unmixed, we show that $\Delta_\mathcal{C}$ is pure
shellable. We are able to describe, in combinatorial and algebraic terms, when
$\Delta_\mathcal{C}$ is pure. If $\mathcal{C}$ has no cycles of length 3 or 4,
then it is shown that $\Delta_\mathcal{C}$ is pure if and only if
$\Delta_\mathcal{C}$ is pure shellable (in this case $e_i$ has a free vertex
for all $i$), and that $\Delta_\mathcal{C}$ is pure if and only if for any two
edges $f_1,f_2$ of $\mathcal{C}$ and for any $e_i$, one has that $f_1\cap
e_i\subset f_2\cap e_i$ or $f_2\cap e_i\subset f_1\cap e_i$. It is also shown
that this ordering condition implies that $\Delta_\mathcal{C}$ is pure
shellable, without any assumption on the cycles of $\mathcal{C}$. Then we prove
that complete admissible uniform clutters and their Alexander duals are
unmixed. In addition, the edge ideals of complete admissible uniform clutters
are facet ideals of shellable simplicial complexes, they are Cohen-Macaulay,
and they have linear resolutions. Furthermore if $ \mathcal{C}$ is admissible
and complete, then $\mathcal{C}$ is unmixed. We characterize certain conditions
that occur in a Cohen-Macaulay criterion for bipartite graphs of Herzog and
Hibi, and extend some results of Faridi--on the structure of unmixed simplicial
trees--to clutters with the K\"onig property without 3-cycles or 4-cycles.


title: Near-infrared VLT adaptive optics imaging of evolved stars

abstract:
  The high angular resolution and dynamic range achieved by the NACO adaptive
optics system on the VLT is an excellent tool to study the morphology of
Planetary Nebulae (PNe). We observed four stars in different evolutionary
stages from the AGB to the PNe phase.
  The images of the inner parts of the PN Hen 2-113 reveal the presence of a
dusty torus tilted with respect to all the other structures of the nebula and
the present of hot dust close to the hot central star. The NACO observations of
Roberts 22 reveal an amazingly complex nebular morphology with a S-shape that
can be interpreted in terms of the 'warped disc' scenario of Icke (2003).
  Combined NACO and MIDI (the VLTI mid-infrared interferometer) observations of
the nebula OH 231.8+4.2 have enabled us to resolve a very compact (diameter of
30-40 mas, corresponding to 40-50 a.u.) dusty structure in the core of the
nebula. Finally, recent observations of the AGB star V Hydrae show that this
star present a departure from spherical symmetry in its inner shell and is
probably on its way to become an asymmetrical planetary nebula. These
observations show that NACO is a great instrument for the discovery and study
of small structures in circumstellar envelopes and PNe and a good complement to
interferometric devices.


title:
The $J$-matrix inverse scattering approach for coupled channels with
  different thresholds

abstract:
  The inverse scattering method within the $J$-matrix approach to the two
coupled-channel problem is discussed. We propose a generalization of the
procedure to the case with different thresholds.


title: Differential Twisted K-theory and Applications

abstract:
  In this paper, we develop differential twisted K-theory and define a twisted
Chern character on twisted K-theory which depends on a choice of connection and
curving on the twisting gerbe. We also establish the general Riemann-Roch
theorem in twisted K-theory and find some applications in the study of twisted
K-theory of compact simple Lie groups.


title: Functional Time Evolution, Anomaly Potentials, and the Geometric Phase

abstract:
  A free quantum field in 1+1 dimensions admits unitary Schrodinger picture
dynamics along any foliation of spacetime by Cauchy curves. Kuchar showed that
the Schrodinger picture state vectors, viewed as functionals of spacelike
embeddings, satisfy a functional Schrodinger equation in which the generators
of time evolution are the scalar field energy-momentum densities with a
particular normal-ordering and with a (non-unique) c-number contribution. The
c-number contribution to the Schrodinger equation, called the ``anomaly
potential'', is needed to make the equation integrable in light of the
Schwinger terms present in the commutators of the normal-ordered
energy-momentum densities. Here we give a quantum geometric interpretation of
the anomaly potential. In particular, we show the anomaly potential corresponds
to the expression in a gauge of the natural connection on the bundle of vacuum
states over the space of embeddings of Cauchy curves into the spacetime. The
holonomy of this connection is the geometric phase associated with dynamical
evolution along a closed path in the space of embeddings generated by the
normal-ordered energy-momentum densities. The presence of the anomaly potential
in the functional Schrodinger equation provides a dynamical phase which removes
this holonomy, so that there is no net phase change for quantum transport
around closed loops in the space of embeddings.


title:
Air fluorescence measurements in the spectral range 300-420 nm using a
  28.5 GeV electron beam

abstract:
  Measurements are reported of the yield and spectrum of fluorescence, excited
by a 28.5 GeV electron beam, in air at a range of pressures of interest to
ultra-high energy cosmic ray detectors. The wavelength range was 300 - 420 nm.
System calibration has been performed using Rayleigh scattering of a nitrogen
laser beam. In atmospheric pressure dry air at 304 K the yield is 20.8 +/- 1.6
photons per MeV.


title: Comments on the observation of quantum oscillations in cuprates

abstract:
  This paper comments on the recently reported quantum oscillations in
underdoped YBCO crystals. The implications to other experiments and some
hurdles to validating the proposed interpretation are discussed.


title: Phase Diffusion in Single-Walled Carbon Nanotube Josephson Transistors

abstract:
  We investigate electronic transport in Josephson junctions formed by
single-walled carbon nanotubes coupled to superconducting electrodes. We
observe enhanced zero-bias conductance (up to 10e^2/h) and pronounced
sub-harmonic gap structures in differential conductance, which arise from the
multiple Andreev reflections at superconductor/nanotube interfaces. The
voltage-current characteristics of these junctions display abrupt switching
from the supercurrent branch to resistive branch, with a gate-tunable switching
current ranging from 50 pA to 2.3 nA. The finite resistance observed on the
supercurrent branch and the magnitude of the switching current are in good
agreement with calculation based on the model of classical phase diffusion.


title:
Detection of fidelity and multiparticle entanglement for arbitrary graph
  states

abstract: withdrawn by the authors because of an error.


title: Soliton Solution for the Spin Current in Ferromagnetic Nanowire

abstract:
  We investigate the interaction of a periodic solution and one-soliton
solution for the spin-polarized current in a uniaxial ferromagnetic nanowire.
The amplitude and wave number of the periodic solution for the spin current
have the different contribution to the width, velocity, and the amplitude of
soliton solution, respectively. Moreover, we found that the soliton can be
trapped only in space with a proper condition. At last we analyze the
modulation instability and discuss dark solitary wave propagation for the spin
current on the background of a periodic solution. In some special cases the
solution can be expressed by the linear combination of periodic solution and
soliton solution.


title: Holographic dark energy in a cyclic universe

abstract:
  In this paper we study the cosmological evolution of the holographic dark
energy in a cyclic universe, generalizing the model of holographic dark energy
proposed by Li. The holographic dark energy with $c<1$ can realize a quintom
behavior; namely, it evolves from a quintessence-like component to a
phantom-like one. The holographic phantom energy density grows rapidly and
dominates the late-time expanding phase, helping realize a cyclic universe
scenario in which the high energy regime is modified by the effects of quantum
gravity, causing a turnaround (and a bounce) of the universe. The dynamical
evolution of holographic dark energy in the regimes of low energy and high
energy is governed by two differential equations, respectively. It is of
importance to link the two regimes for this scenario. We propose a link
condition giving rise to a complete picture of holographic evolution of a
cyclic universe.


title:
An analog of the Iwasawa conjecture for a complete hyperbolic threefold
  of finite volume

abstract:
  For a unitary local system of rank one on a complete hyperbolic threefold of
finite volume which has only one cusp, we will compare the order of the
Alexander invariant at t=1 and one of Ruelle-Selberg L-function at s=0. Our
result may be considered as a geometric analog of the Iwasawa main conjecture
in the algebraic number theory.


title: On a special value of the Ruelle L-function

abstract:
  For a unitary local system of rank one on a complete hyperbolic threefold of
finite volume which has only one cusp, the Ruelle L-function is defined. We
will show that if the first cohomology group of the local system vanishes its
value at s=0 is equal to the square of the Franz-Reidemeister torsion.


title: Asymptotic eigenvalue distribution of large Toeplitz matrices

abstract:
  We study the asymptotic eigenvalue distribution of Toeplitz matrices
generated by a singular symbol. It has been conjectured by Widom that, for a
generic symbol, the eigenvalues converge to the image of the symbol. In this
paper we ask how the eigenvalues converge to the image. For a given Toeplitz
matrix $T_n(a)$ of size $n$, we take the standard approach of looking at
$\det(\zeta-T_n(a))$, of which the asymptotic information is given by the
Fisher-Hartwig theorem. For a symbol with single jump, we obtain the
distribution of eigenvalues as an expansion involving $1/n$ and $\log n/n$. To
demonstrate the validity of our result we compare our result against the
numerics using a pure Fisher-Hartwig symbol.


title: Control of spin coherence in semiconductor double quantum dots

abstract:
  We propose a scheme to manipulate the spin coherence in vertically coupled
GaAs double quantum dots. Up to {\em ten} orders of magnitude variation of the
spin relaxation and {\em two} orders of magnitude variation of the spin
dephasing can be achieved by a small gate voltage applied vertically on the
double dot. Specially, large variation of spin relaxation still exists at 0 K.
In the calculation, the equation-of-motion approach is applied to obtain the
electron decoherence time and all the relevant spin decoherence mechanisms,
such as the spin-orbit coupling together with the electron--bulk-phonon
scattering, the direct spin-phonon coupling due to the phonon-induced strain,
the hyperfine interaction and the second-order process of electron-phonon
scattering combined with the hyperfine interaction, are included. The condition
to obtain the large variations of spin coherence is also addressed.


title: Semilattice Structures of Spreading Models

abstract:
  Given a Banach space X, denote by SP_{w}(X) the set of equivalence classes of
spreading models of X generated by normalized weakly null sequences in X. It is
known that SP_{w}(X) is a semilattice, i.e., it is a partially ordered set in
which every pair of elements has a least upper bound. We show that every
countable semilattice that does not contain an infinite increasing sequence is
order isomorphic to SP_{w}(X) for some separable Banach space X.


title: Question on Conditional Entropy

abstract:
  The problems of conditional entropy's definition and the formula to compute
conditional entropy are analyzed from various perspectives, and the corrected
computing formula is presented. Examples are given to prove the conclusion that
conditional entropy never be increased is not absolute, thus the representation
that information is to decrease uncertainty in the definition of information is
not absolutely correct.


title: The u-invariant of the function fields of p-adic curves

abstract:
  The u-invariant of a field is the maximum dimension of ansiotropic quadratic
forms over the field. It is an open question whether the u-invariant of
function fields of p-aidc curves is 8. In this paper, we answer this question
in the affirmative for function fields of non-dyadic p-adic curves.


title: Entanglement cost and distillable entanglement of symmetric states

abstract:
  We compute entanglement cost and distillable entanglement of states supported
on symmetric subspace. Not only giving general formula, we apply them to the
output states of optimal cloning machines. Surprisingly, under some settings,
the optimal n to m clone and true m copies are the same in entanglement
measures. However, they differ in the error exponent of entanglement dilution.
We also presented a general theory of entanglement dilution which is applicable
to any non-i.i.d sequence of states.


title:
Equation of state for shock-compressed porous molybdenum from
  first-principles mean-field potential calculations

abstract:
  The Hugoniot curves for shock-compressed molybdenum with initial porosities
of 1.0, 1.26, 1.83, and 2.31 are theoretically investigated. The method of
calculations combines the first-principles treatment for zero- and
finite-temperature electronic contribution and the mean-field-potential
approach for the ion-thermal contribution to the total free energy. Our
calculated results reproduce the Hugoniot properties of porous molybdenum quite
well. At low porosity, in particular, the calculations show a complete
agreement with the experimental measurements over the full range of data. For
the two large porosity values of 1.83 and 2.31, our results are well in accord
with the experimental data points up to the particle velocity of 3.5 km/s, and
tend to overestimate the shock-wave velocity and Hugoniot pressure when further
increasing the particle velocity. In addition, the temperature along the
principal Hugoniot is also extensively investigated for porous molybdenum.


title: Scattering of spin-polarized electron in an Aharonov--Bohm potential

abstract:
  The scattering of spin-polarized electrons in an Aharonov--Bohm vector
potential is considered. We solve the Pauli equation in 3+1 dimensions taking
into account explicitly the interaction between the three-dimensional spin
magnetic moment of electron and magnetic field. Expressions for the scattering
amplitude and the cross section are obtained for spin-polarized electron
scattered off a flux tube of small radius. It is also shown that bound electron
states cannot occur in this quantum system. The scattering problem for the
model of a flux tube of zero radius in the Born approximation is briefly
discussed.

categories: hep-th cond-mat.other math-ph math.MP quant-ph


title: Casimir Forces in Trapped Dilute Bose Gas Between Two Slabs

abstract:
  We discuss a Casimir force due to zero-temperature quantum fluctuations in a
weakly interacting Bose-Einstein condensate (BEC) with a strong harmonic trap.
The results show that the presence of a strong harmonic trap changes the power
law behavior of Casimir force due to the dimensional reduction effect. At
finite temperature, we calculate Casimir force due to thermal fluctuation and
find an exotic temperature dependent behavior in the first order term. Finally,
we speculate some possible experimental realization and detection of the force
in future experiments.


title:
Elliptical hole pockets in the Fermi surfaces of unhydrated and hydrated
  sodium cobalt oxides

abstract:
  The surprise discovery of superconductivity below 5K in sodium cobalt oxides
when hydrated with water has caught the attention of experimentalists and
theorists alike. Most explanations for its occurence have focused heavily on
the properties of some small elliptically shaped pockets predicted to be the
electronically dominant Fermi surface sheet, but direct attempts to look for
them have instead cast serious doubts over their existence. Here we present
evidence that these pockets do indeed exist, based on bulk measurements of the
electron momentum distribution in unhydrated and hydrated sodium cobalt oxides
using the technique of x-ray Compton scattering.


title: Pseudoknot RNA Structures with Arc-Length $\ge 3$

abstract:
  In this paper we study $k$-noncrossing RNA structures with arc-length $\ge
3$, i.e. RNA molecules in which for any $i$, the nucleotides labeled $i$ and
$i+j$ ($j=1,2$) cannot form a bond and in which there are at most $k-1$
mutually crossing arcs. Let ${\sf S}_{k,3}(n)$ denote their number. Based on a
novel functional equation for the generating function $\sum_{n\ge 0}{\sf
S}_{k,3}(n)z^n$, we derive for arbitrary $k\ge 3$ exponential growth factors
and for $k=3$ the subexponential factor. Our main result is the derivation of
the formula ${\sf S}_{3,3}(n) \sim \frac{6.11170\cdot 4!}{n(n-1)...(n-4)}
4.54920^n$.


title: Mid-Infrared Instrumentation for the European Extremely Large Telescope

abstract:
  MIDIR is the proposed thermal/mid-IR imager and spectrograph for the European
Extremely Large Telescope (E-ELT). It will cover the wavelength range of 3 to
at least 20 microns. Designed for diffraction-limited performance over the
entire wavelength range, MIDIR will require an adaptive optics system; a
cryogenically cooled system could offer optimal performance in the IR, and this
is a critical aspect of the instrument design. We present here an overview of
the project, including a discussion of MIDIR's science goals and a comparison
with other infrared (IR) facilities planned in the next decade; top level
requirements derived from these goals are outlined. We describe the optical and
mechanical design work carried out in the context of a conceptual design study,
and discuss some important issues to emerge from this work, related to the
design, operation and calibration of the instrument. The impact of telescope
optical design choices on the requirements for the MIDIR instrument is
demonstrated.


title: Atmospheric instability as a loss of a metastable equilibrium

abstract:
  General thermodynamic theory of metastable states is used in this short note
to try to understand better atmospheric instabilities. It is shown that not
only cooling of a cloud can lead to rain, but heating also, especially when
there are charged water drops in a cloud (in this case we have rain with
lightning). The influence of the global warming on weather is discussed.


title:
Recent Developments on Kaon Condensation and Its Astrophysical
  Implications

abstract:
  We discuss three different ways to arrive at kaon condensation at n_c = 3 n_0
where n_0 is nuclear matter density: (1) Fluctuating around the n=0 vacuum in
chiral perturbation theory, (2) fluctuating around n_VM near the chiral
restoration density n_chi where the vector manifestation of hidden local
symmetry is reached and (3) fluctuating around the Fermi liquid fixed point at
n_0. They all share one common theoretical basis, "hidden local symmetry." We
argue that when the critical density n_c < n_chi is reached in a neutron star,
the electrons turn into K^- mesons, which go into an S-wave Bose condensate.
This reduces the pressure substantially and the neutron star goes into a black
hole. Next we develop the argument that the collapse of a neutron star into a
black hole takes place for a star of M = 1.5 M_sun. This means that Supernova
1987A had a black hole as result. We also show that two neutron stars in a
binary have to be within 4% of each other in mass, for neutron stars
sufficiently massive that they escape helium shell burning. For those that are
so light that they do have helium shell burning, after a small correction for
this they must be within 4% of each other in mass. Observations support the
proximity in mass inside of a neutron star binary. The result of strangeness
condensation is that there are 5 times more low-mass black-hole, neutron-star
binaries than double neutron-star binaries although the former are difficult to
observe.


title:
Dynamics of condensation of wetting layer in time-dependent
  Ginzburg-Landau model

abstract:
  The dynamics of liquid condensation on a substrate or within a capillary is
studied when the wetting film grows via interface-limited growth. We use a
phenomenological time-dependent Ginzburg-Landau (TDGL)-type model with
long-range substrate potential. Using an order parameter, which does not
directly represent the density, we can derive an analytic formula for the
interfacial growth velocity that is directly related to the substrate
potential. Using this analytic expression the growth of wetting film is shown
to conform to a power-law-type growth, which is due to the presence of a
long-range dispersion force.


title: Baryon vector and axial content up to the 7Q component

abstract:
  We have used the light-cone formulation of Chiral-Quark Soliton Model to
investigate the vector and axial content of octet, decuplet and the
hypothetical antidecuplet in the flavor SU(3) symmetry limit. We have extended
previous works by computing the 7Q contribution to vector and axial charges for
the octet and antidecuplet but stayed at the 5Q sector for the decuplet where
the full computation needs much more time. As expected the 7Q component has a
weaker impact on the quantities but still changes them by a few percent. We
give also a detailed decomposition of those charges into flavor, valence quark,
sea quark and antiquark contributions. Many of them are of course not (yet)
measured or estimated and constitute then a theoretical estimation. Among the
different interesting observations made in this work are the explicit
quadrupole deformation of decuplet baryons due to the pion field and the sum of
quark spins larger than the pentaquark one.


title:
Optical Identification of 15 Micron Sources in the AKARI Performance
  Verification Field toward the North Ecliptic Pole

abstract:
  We present the results of optical identifications for 257 mid-infrared
sources detected with a deep 15um survey over approximately 80 arcmin^2 area in
the AKARI performance verification field near the North Ecliptic Pole. The 15um
fluxes of the sources range from 1 mJy down to 40 uJy, approximately a half of
which are below 100 uJy. Optical counterparts were searched for within a 2-3
arcsec radius in both the BVRi'z' catalog generated by using the deep
Subaru/Suprime-cam field which covers one-third of the performance verification
field, and the g'r'i'z' catalog based on observations made with MegaCam at
CFHT. We found B-R and R-z' colours of sources with successful optical
identifications are systematically redder than that of the entire optical
sample in the same field. Moreover, approximately 40% of the 15um sources show
colours R-L15>5, which cannot be explained by the spectral energy distribution
(SED) of normal quiescent spiral galaxies, but are consistent with SEDs of
redshifted (z>1) starburst or ultraluminous infrared galaxies. This result
indicates that the fraction of the ultraluminous infrared galaxies in our faint
15um sample is much larger than that in our brighter 15um sources, which is
consistent with the evolving mid-infrared luminosity function derived by recent
studies based on the Spitzer 24um deep surveys. Based on an SED fitting
technique, the nature of the faint 15um sources is further discussed for a
selected number of sources with available K_s-band data.


title: On the universality of the Discrete Nonlinear Schroedinger Equation

abstract:
  We address the universal applicability of the discrete nonlinear Schroedinger
equation. By employing an original but general top-down/bottom-up procedure
based on symmetry analysis to the case of optical lattices, we derive the most
widely applicable and the simplest possible model, revealing that the discrete
nonlinear Schroedinger equation is ``universally'' fit to describe light
propagation even in discrete tensorial nonlinear systems and in the presence of
nonparaxial and vectorial effects.


title: Basic principle of superconductivity

abstract:
  The basic principle of superconductivity is suggested in this paper. There
have been two vital wrong suggestions on the basic principle, one is the
relation between superconductivity and the Bose-Einstein condensation (BEC),
and another is the relation between superconductivity and pseudogap.


title:
Statistical Approach to the Cosmological-Constant Problem on Brane
  Worlds

abstract:
  We investigate the physically accepted solutions of general Braneworld
scenarios, scanning uniformly the associated parameter space. Without making
any further assumptions we find that solutions which give "small" Hubble
parameters on the physical brane, and therefore "small" effective cosmological
constants on the 4D Universe, are far more probable than those with "large"
ones. Eventually, their distribution tends to the $\delta$-function in the
limit of continuous covering of the parameter space.


title: Noether theorem for mu-symmetries

abstract:
  We give a version of Noether theorem adapted to the framework of
mu-symmetries; this extends to such case recent work by Muriel, Romero and
Olver in the framework of lambda-symmetries, and connects mu-symmetries of a
Lagrangian to a suitably modified conservation law. In some cases this
"mu-conservation law'' actually reduces to a standard one; we also note a
relation between mu-symmetries and conditional invariants. We also consider the
case where the variational principle is itself formulated as requiring
vanishing variation under mu-prolonged variation fields, leading to modified
Euler-Lagrange equations. In this setting mu-symmetries of the Lagrangian
correspond to standard conservation laws as in the standard Noether theorem. We
finally propose some applications and examples.


title: Thermodynamics of regular black hole

abstract:
  We investigate thermodynamics for a magnetically charged regular black hole
(MCRBH), which comes from the action of general relativity and nonlinear
electromagnetics, comparing with the Reissner-Norstr\"om (RN) black hole in
both four and two dimensions after dimensional reduction. We find that there is
no thermodynamic difference between the regular and RN black holes for a fixed
charge $Q$ in both dimensions. This means that the condition for either
singularity or regularity at the origin of coordinate does not affect the
thermodynamics of black hole. Furthermore, we describe the near-horizon AdS$_2$
thermodynamics of the MCRBH with the connection of the Jackiw-Teitelboim
theory. We also identify the near-horizon entropy as the statistical entropy by
using the AdS$_2$/CFT$_1$ correspondence.


title: Absorption cross section of RN black hole

abstract:
  The behavior of a charged scalar field in the RN black hole space time is
studied using WKB approximation. In the present work it is assumed that matter
waves can get reflected from the event horizon. Using this effect, the Hawking
temperature and the absorption cross section for RN black hole placed in a
charged scalar field are calculated. The absorption cross section $\sigma
_{abs}$ is found to be inversely proportional to square of the Hawking
temperature of the black hole.


title: Controllability of Quantum Systems on the Lie Group SU(1,1)

abstract:
  This paper examines the controllability for quantum control systems with
SU(1,1) dynamical symmetry, namely, the ability to use some electromagnetic
field to redirect the quantum system toward a desired evolution. The problem is
formalized as the control of a right invariant bilinear system evolving on the
Lie group SU(1,1) of two dimensional special pseudo-unitary matrices. It is
proved that the elliptic condition of the total Hamiltonian is both sufficient
and necessary for the controllability. Conditions are also given for small time
local controllability and strong controllability. The results obtained are also
valid for the control systems on the Lie groups SO(2,1) and SL(2,R).


title:
R-symmetry, supersymmetry breaking and metastable vacua in global and
  local supersymmetric theories

abstract:
  We study N=1 global and local supersymmetric theories with a continuous
global $U(1)_R$ symmetry as models of dynamical supersymmetry (SUSY) breaking.
We introduce explicit R-symmetry breaking terms into such models, in particular
a generalized O'Raifeartaigh model. Such explicit R-symmetry breaking terms can
lead to a SUSY preserving minimum. We classify explicit R-symmetry breaking
terms by the structure of newly appeared SUSY stationary points as a
consequence of the R-breaking effect, which could make the SUSY breaking vacuum
metastable. We show that the R-breaking terms are basically divided into two
categories. One of them does not generate a SUSY solution, or yields SUSY
solutions that disappear in the case of supergravity when we tune a parameter
so that the original SUSY breaking minimum becomes a Minkowski vacuum. We also
show that the general argument by Nelson and Seiberg for a dynamical SUSY
breaking still holds with a local SUSY except for a certain nontrivial case,
and present concrete examples of the exception.


title: Convexity of Hypersurfaces in Spherical Spaces

abstract:
  A spherical set is called convex if for every pair of its points there is at
least one minimal geodesic segment that joins these points and lies in the set.
We prove that for n >= 3 a complete locally-convex (topological) immersion of a
connected (n-1)-manifold into the n-sphere is a surjection onto the boundary of
a convex set.


title: Unrecognized Backscattering in Low Energy Beta Spectroscopy

abstract:
  We present studies on electron backscattering from the surface of plastic
scintillator beta detectors. By using a setup of two detectors coaxial with a
strong external magnetic field - one detector serving as primary detector, the
other as veto-detector to detect backscattering - we investigate amount and
spectrum of unrecognized backscattering, i.e. events where only one detector
recorded a trigger signal. The implications are important for low energy
particle physics experiments.


title: Natural Frobenius Submanifolds

abstract:
  I.A.B. Strachan introduced the notion of a natural Frobenius submanifold of a
Frobenius manifold and gave a sufficient but not necessary condition for a
submanifold to be a natural Frobenius submanifold. This paper will give a
necessary and sufficient condition and classify the natural Frobenius
hypersurfaces.


title:
An asymptotically stable scheme for diffusive coagulation-fragmentation
  models

abstract:
  This paper is devoted to the analysis of a numerical scheme for the
coagulation and fragmentation equation with diffusion in space. A finite volume
scheme is developed, based on a conservative formulation of the space
nonhomogeneous coagulation-fragmentation model, it is shown that the scheme
preserves positivity, total volume and global steady states. Finally, several
numerical simulations are performed to investigate the long time behavior of
the solution.


title:
Symmetries and conservation laws in Lagrangian gauge theories with
  applications to the mechanics of black holes and to gravity in three
  dimensions

abstract:
  The treatment of exact conservation laws in Lagrangian gauge theories
constitutes the main axis of the first part of the thesis. The formalism is
developed as a self-consistent theory but is inspired by earlier works, mainly
by cohomological results, covariant phase space methods and by the Hamiltonian
formalism. The thermodynamical properties of black holes, especially the first
law, are studied in a general geometrical setting and are worked out for
several black objects: black holes, strings and rings. Also, the geometrical
and thermodynamical properties of a new family of black holes with closed
timelike curves in three dimensions are described.
  The second part of the thesis is the natural generalization of the first part
to asymptotic analyses. We start with a general construction of covariant phase
spaces admitting asymptotically conserved charges. The representation of the
asymptotic symmetry algebra by a covariant Poisson bracket among the conserved
charges is then defined and is shown to admit generically central extensions.
The asymptotic structures of three three-dimensional spacetimes are then
studied in detail and the consequences for quantum gravity in three dimensions
are discussed.


title:
Two-way classical communication remarkably improves local
  distinguishability

abstract:
  We analyze the difference in the local distinguishability among the following
three restrictions; (i) Local operations and only one-way classical
communications (one-way LOCC) are permitted. (ii) Local operations and two-way
classical communications (two-way LOCC) are permitted. (iii) All separable
operations are permitted. We obtain two main results concerning the
discrimination between a given bipartite pure state and the completely mixed
state with the condition that the given state should be detected perfectly. As
the first result, we derive the optimal discrimination protocol for a bipartite
pure state in the cases (i) and (iii). As the second result, by constructing a
concrete two-way local discrimination protocol, it is proven that the case (ii)
is much better than the case (i), i.e., two-way classical communication
remarkably improves the local distinguishability in comparison with one-way
classical communication at least for a low-dimensional bipartite pure state.


title: Sfermion masses in the supersymmetric economical 3-3-1 model

abstract:
  Sfermion masses and eigenstates in the supersymmetric economical 3-3-1 model
are studied. By lepton number conservation, the exotic squarks and
superpartners of ordinary quarks are decoupled. Due to the fact that in the
3-3-1 models, one generation of quarks behaves differently from other two, by
R-parity conservation, the mass mixing matrix of the squarks in this model are
smaller than that in the Minimal Supersymmetric Standard Model (MSSM). Assuming
substantial mixing in pairs of highest flavours, we are able to get mass
spectrum and eigenstates of all the sfermions. In the effective approximation,
the slepton mass splittings in the first two generations, are consistent with
those in the MSSM, namely: $ m^2_{\tilde{l}_L} - m^2_{\tilde{\nu}_{l L}} =
m_W^2 \cos 2\ga$ $(l=e, \mu)$. In addition, within the above effective limit,
there exists degeneracy among sneutrinos in each multiplet:
$m^2_{\tilde{\nu}_{l L}} = m^2_{\tilde{\nu}_{l R}}$. In contradiction to the
MSSM, the squark mass splittings are different for each generation and not to
be $ m_W^2 \cos 2\ga$.


title:
Infrared point source variability between the Spitzer and MSX surveys of
  the Galactic mid-plane

abstract:
  We present a list of 552 sources with suspected variability, based on a
comparison of mid-infrared photometry from the GLIMPSE I and MSX surveys, which
were carried out nearly a decade apart. We were careful to address issues such
as the difference in resolution and sensitivity between the two surveys, as
well as the differences in the spectral responses of the instruments. We
selected only sources where the IRAC 8.0 and MSX 8.28 micron fluxes differ by
more than a factor of two, in order to minimize contamination from sources
where the difference in fluxes at 8 micron is due to a strong 10 micron
silicate feature. We present a subset of 40 sources for which additional
evidence suggests variability, using 2MASS and MIPSGAL data. Based on a
comparison with the variability flags in the IRAS and MSX Point-Source Catalogs
we estimate that at least a quarter of the 552 sources, and at least half of
the 40 sources are truly variable. In addition, we tentatively confirm the
variability of one source using multi-epoch IRAS LRS spectra. We suggest that
most of the sources in our list are likely to be Asymptotic Giant Branch stars.


title:
The Maslov cocycle, smooth structures and real-analytic complete
  integrability

abstract:
  This paper studies smooth obstructions to integrability and proves two main
results. First, it is shown that if a smooth topological n-torus admits a
real-analytically completely integrable convex hamiltonian on its cotangent
bundle, then the torus is diffeomorphic to the standard n-torus. This is the
first known result where the smooth structure of a manifold obstructs complete
integrability. Second, it is proven that each one of the Witten-Kreck-Stolz
7-manifolds admit a real-analytically completely integrable geodesic flow on
its cotangent bundle. This gives examples of topological manifolds all of whose
smooth structures admit a real-analytically completely integrable convex
hamiltonian on its cotangent bundle. Additional examples are provided by
Eschenburgh and Aloff-Wallach spaces.


title: An expression for stationary distribution in nonequilibrium steady state

abstract:
  We study the nonequilibrium steady state realized in a general stochastic
system attached to multiple heat baths and/or driven by an external force.
Starting from the detailed fluctuation theorem we derive concise and suggestive
expressions for the corresponding stationary distribution which are correct up
to the second order in thermodynamic forces. The probability of a microstate
$\eta$ is proportional to $\exp[{\Phi}(\eta)]$ where
${\Phi}(\eta)=-\sum_k\beta_k\mathcal{E}_k(\eta)$ is the excess entropy change.
Here $\mathcal{E}_k(\eta)$ is the difference between two kinds of conditioned
path ensemble averages of excess heat transfer from the $k$-th heat bath whose
inverse temperature is $\beta_k$. Our expression may be verified experimentally
in nonequilibrium states realized, for example, in mesoscopic systems.


title: Four-dimensional double singular oscillator

abstract:
  The Schr\"odinger equation for the four-dimensional double singular
oscillator is separable in Eulerian, doble polar and spheroidal coordinates in
${\rm I R}^4$. It is shown that the coefficients for the expansion of double
polar basis in terms of the Eulerian basis can be expressed through the
Clebsch-Gordan coefficients of the group SU(2) analytically continued to real
values of their arguments. The coefficients for the expansions of the
spheroidal basis in terms of the Eulerian and double polar bases are proved to
satisfy three-term recursion relations.


title: Graphene-like massless Dirac fermions in Harper systems

abstract:
  It is shown that systems described by Harper's equation exhibit a Dirac point
at the center of the spectrum whenever the field parameter is a fraction of
even denominator. The Dirac point is formed by the touching of two subbands,
and the physics around such point is characterized by the relative field only,
as if the latter were null at the reference value. Such behavior is consistent
with the nesting property conjectured by Hofstadter, and its experimental
verification would give support to such hypothesis as well as the
Peierls-Onsager ansatz used to arrive at Harper's equation when crystalline
electrons move in a uniform external magnetic field


title:
Ground State Properties of an Asymmetric Hubbard Model for Unbalanced
  Ultracold Fermionic Quantum Gases

abstract:
  In order to describe unbalanced ultracold fermionic quantum gases on optical
lattices in a harmonic trap, we investigate an attractive ($U<0$) asymmetric
($t_\uparrow\neq t_\downarrow$) Hubbard model with a Zeeman-like magnetic
field. In view of the model's spatial inhomogeneity, we focus in this paper on
the solution at Hartree-Fock level. The Hartree-Fock Hamiltonian is
diagonalized with particular emphasis on superfluid phases. For the special
case of spin-independent hopping we analytically determine the number of
solutions of the resulting self-consistency equations and the nature of the
possible ground states at weak coupling. Numerical results for unbalanced
Fermi-mixtures are presented within the local density approximation. In
particular, we find a fascinating shell structure, involving normal and
superfluid phases. For the general case of spin-dependent hopping we calculate
the density of states and the possible superfluid phases in the ground state.
In particular, we find a new magnetized superfluid phase.


title: Frustrated minority spins in GeNi2O4

abstract:
  Recently, two consecutive phase transitions were observed, upon cooling, in
an antiferromagnetic spinel GeNi$_2$O$_4$ at $T_{N1}=12.1$ K and $T_{N2}=11.4$
K, respectively \cite{matsuno, crawford}. Using unpolarized and polarized
elastic neutron scattering we show that the two transitions are due to the
existence of frustrated minority spins in this compound. Upon cooling, at
$T_{N1}$ the spins on the $<111>$ \kagome planes order ferromagnetically in the
plane and antiferromagnetically between the planes (phase I), leaving the spins
on the $<111>$ triangular planes that separate the \kagome planes frustrated
and disordered. At the lower $T_{N2}$, the triangular spins also order in the
$<111>$ plane (phase II). We also present a scenario involving exchange
interactions that qualitatively explains the origin of the two purely magnetic
phase transitions.


title: Jeans type analysis of chemotactic collapse

abstract:
  We perform a linear dynamical stability analysis of a general hydrodynamic
model of chemotactic aggregation [Chavanis & Sire, Physica A, in press (2007)].
Specifically, we study the stability of an infinite and homogeneous
distribution of cells against "chemotactic collapse". We discuss the analogy
between the chemotactic collapse of biological populations and the
gravitational collapse (Jeans instability) of self-gravitating systems. Our
hydrodynamic model involves a pressure force which can take into account
several effects like anomalous diffusion or the fact that the organisms cannot
interpenetrate. We also take into account the degradation of the chemical which
leads to a shielding of the interaction like for a Yukawa potential. Finally,
our hydrodynamic model involves a friction force which quantifies the
importance of inertial effects. In the strong friction limit, we obtain a
generalized Keller-Segel model similar to the generalized Smoluchowski-Poisson
system describing self-gravitating Langevin particles. For small frictions, we
obtain a hydrodynamic model of chemotaxis similar to the Euler-Poisson system
describing a self-gravitating barotropic gas. We show that an infinite and
homogeneous distribution of cells is unstable against chemotactic collapse when
the "velocity of sound" in the medium is smaller than a critical value. We
study in detail the linear development of the instability and determine the
range of unstable wavelengths, the growth rate of the unstable modes and the
damping rate, or the pulsation frequency, of the stable modes as a function of
the friction parameter and shielding length. For specific equations of state,
we express the stability criterion in terms of the density of cells.


title: Algebraic systems of matrices and Grobner basis

abstract:
  One studies a particular algebraic system where the unknowns are matrices. We
solve this system according to the parameters values thanks to the theory of
Grobner basis.


title:
Sharp Magnetic Field Dependence of the 2D Hall Coefficient Induced by
  Classical Memory Effects

abstract:
  We show that a sharp dependence of the Hall coefficient $R$ on the magnetic
field $B$ arises in two-dimensional electron systems with randomly located
strong scatterers. The phenomenon is due to classical memory effects. We
calculate analytically the dependence $R(B)$ for the case of scattering by hard
disks of radius $a$, randomly distributed with concentration $n_0\ll1/a^2$. We
demonstrate that in very weak magnetic fields ($\omega_c\tau \lesssim n_0a^2$)
memory effects lead to a considerable renormalization of the Boltzmann value of
the Hall coefficient: $\delta R / R \sim 1 .$ With increasing magnetic field,
the relative correction to $R$ decreases, then changes sign, and saturates at
the value $\delta R / R \sim -n_0a^2 .$ We also discuss the effect of the
smooth disorder on the dependence of $R$ on $B$.


title:
Web Server Benchmark Application WiiBench using Erlang/OTP R11 and
  Fedora-Core Linux 5.0

abstract:
  As the web grows and the amount of traffics on the web server increase,
problems related to performance begin to appear. Some of the problems, such as
the number of users that can access the server simultaneously, the number of
requests that can be handled by the server per second (requests per second) to
bandwidth consumption and hardware utilization like memories and CPU. To give
better quality of service (\textbf{\textit{QoS}}), web hosting providers and
also the system administrators and network administrators who manage the server
need a benchmark application to measure the capabilities of their servers.
Later, the application intends to work under Linux/Unix -- like platforms and
built using Erlang/OTP R11 as a concurrent oriented language under Fedora Core
Linux 5.0. \textbf{\textit{WiiBench}} is divided into two main parts, the
controller section and the launcher section. Controller is the core of the
application. It has several duties, such as read the benchmark scenario file,
configure the program based on the scenario, initialize the launcher section,
gather the benchmark results from local and remote Erlang node where the
launcher runs and write them in a log file (later the log file will be used to
generate a report page for the sysadmin). Controller also has function as a
timer which act as timing for user inters arrival to the server. Launcher
generates a number of users based on the scenario, initialize them and start
the benchmark by sending requests to the web server. The clients also gather
the benchmark result and send them to the controller.


title:
Asymmetric Fermi superfluid with different atomic species in a harmonic
  trap

abstract:
  We study the dilute fermion gas with pairing between two species and unequal
concentrations in a harmonic trap using the mean field theory and the local
density approximation. We found that the system can exhibit a superfluid shell
structure sandwiched by the normal fermions. This superfluid shell structure
occurs if the mass ratio is larger then certain critical value which increases
from the weak-coupling BCS region to the strong-coupling BEC side. In the
strong coupling BEC regime, the radii of superfluid phase are less sensitive to
the mass ratios and are similar to the case of pairing with equal masses.
However, the lighter leftover fermions are easier to mix with the superfluid
core than the heavier ones. A partially polarized superfluid can be found if
the majority fermions are lighter, whereas phase separation is still found if
they are heavier.


title: A Generic Approach to Searching for Jacobians

abstract:
  We consider the problem of finding cryptographically suitable Jacobians. By
applying a probabilistic generic algorithm to compute the zeta functions of low
genus curves drawn from an arbitrary family, we can search for Jacobians
containing a large subgroup of prime order. For a suitable distribution of
curves, the complexity is subexponential in genus 2, and O(N^{1/12}) in genus
3. We give examples of genus 2 and genus 3 hyperelliptic curves over prime
fields with group orders over 180 bits in size, improving previous results. Our
approach is particularly effective over low-degree extension fields, where in
genus 2 we find Jacobians over F_{p^2) and trace zero varieties over F_{p^3}
with near-prime orders up to 372 bits in size. For p = 2^{61}-1, the average
time to find a group with 244-bit near-prime order is under an hour on a PC.


title:
Using Josephson junctions to determine the pairing state of
  superconductors without crystal inversion symmetry

abstract:
  Theoretical studies of a planar tunnel junction between two superconductors
with antisymmetric spin-orbit coupling are presented. The half-space Green's
function for such a superconductor is determined. This is then used to derive
expressions for the dissipative current and the Josephson current of the
junction. Numerical results are presented in the case of the Rashba spin-orbit
coupling, relevant to the much studied compound CePt$_3$Si. Current-voltage
diagrams, differential conductance and the critical Josephson current are
presented for different crystallographic orientations and different weights of
singlet and triplet components of the pairing state. The main conclusion is
that Josephson junctions with different crystallographic orientations may
provide a direct connection between unconventional pairing in superconductors
of this kind and the absence of inversion symmetry in the crystal.


title: Holographic QCD with Isospin Chemical Potential

abstract:
  We consider configurations of D4-D8-\bar D8 branes which correspond to large
N QCD with non-vanishing temperature and chemical potential for baryon number
and isospin. We study the holographic dual of this model and find a rich phase
structure. The phases, distinguished by the values of quark condensates, are
separated by the surfaces of first order phase transitions. The picture is in
many respects similar to the expected phase structure of QCD in the chiral
limit.


title: The p53-MDM2 network: from oscillations to apoptosis

abstract:
  The p53 protein is well-known for its tumour suppressor function. The
p53-MDM2 negative feedback loop constitutes the core module of a network of
regulatory interactions activated under cellular stress. In normal cells, the
level of p53 proteins is kept low by MDM2, i.e. MDM2 negatively regulates the
activity of p53. In the case of DNA damage,the p53-mediated pathways are
activated leading to cell cycle arrest and repair of the DNA. If repair is not
possible due to excessive damage, the p53-mediated apoptotic pathway is
activated bringing about cell death. In this paper, we give an overview of our
studies on the p53-MDM2 module and the associated pathways from a systems
biology perspective. We discuss a number of key predictions, related to some
specific aspects of cell cycle arrest and cell death, which could be tested in
experiments.


title:
Fostering Consensus in Multidimensional Continuous Opinion Dynamics
  under Bounded Confidence

abstract:
  Social consensus is important for society. Sometimes the success of society
depends on a consensus (e.g. the decision to pay taxes or to commit to the
constitution). Examples for continuous opinion dynamics are discussions about
tax rates or budget plan proposals for governments investments. Another example
is a commission of experts which should reach a estimate about a certain issue,
e.g. the tax revenues of the next year. In all these situations we got a group
of agents which should reach a common agreement either for reaching a good
approximation to the truth but on the other hand for the reason, that reaching
consensus is a good in itself.
  From social judgment theory and experiments we know that humans either tend
to agreement with others for normative and informational reasons but on the
other hand have bounded confidence against others with differing opinions.
  In a framework of models of continuous opinion dynamics we ask, which
structural conditions foster the achievement of consensus? We present evidence
by simulation that bringing more issues in does, but only if the issues are
under budget constraints. Further, the installation of meetings where everyone
hears all opinions has a better impact than relying on gossip.


title: Electro-Magnetic Waves within a Model for Charged Solitons

abstract:
  We analyze the model of topological fermions (MTF), where charged fermions
are treated as soliton solutions of the field equations. In the region far from
the sources we find plane waves solutions with the properties of
electro-magnetic waves.


title: On the topology of surface singularities {z^n=f(x,y)}, for f irreducible

abstract:
  The splice quotients are an interesting class of normal surface singularities
with rational homology sphere links, defined by W. Neumann and J. Wahl. If
Gamma is a tree of rational curves that satisfies certain combinatorial
conditions, then there exist splice quotients with resolution graph Gamma.
Suppose the equation z^n=f(x,y) defines a surface X_{f,n} with an isolated
singularity at the origin in C^3. For f irreducible, we completely
characterize, in terms of n and a variant of the Puiseux pairs of f, those
X_{f,n} for which the resolution graph satisfies the combinatorial conditions
that are necessary for splice quotients. This result is topological; whether or
not X_{f,n} is analytically isomorphic to a splice quotient is treated
separately.


title:
Fractional charge perspective on the band-gap in density-functional
  theory

abstract:
  The calculation of the band-gap by density-functional theory (DFT) methods is
examined by considering the behavior of the energy as a function of number of
electrons. It is found that the incorrect band-gap prediction with most
approximate functionals originates mainly from errors in describing systems
with fractional charges. Formulas for the energy derivatives with respect to
number of electrons are derived which clarify the role of optimized effective
potentials in prediction of the band-gap. Calculations with a recent functional
that has much improved behavior for fractional charges give a good prediction
of the energy gap and also $\epsilon_{{\rm homo}}\simeq-I$ for finite systems.
Our results indicate it is possible, within DFT, to have a functional whose
eigenvalues or derivatives accurately predict the band-gap.


title:
Integrating out the Dirac sea: Effective field theory approach to
  exactly solvable four-fermion models

abstract:
  We use 1+1 dimensional large N Gross-Neveu models as a laboratory to derive
microscopically effective Lagrangians for positive energy fermions only. When
applied to baryons, the Euler-Lagrange equation for these effective theories
assumes the form of a non-linear Dirac equation. Its solution reproduces the
full semi-classical results including the Dirac sea to any desired accuracy.
Dynamical effects from the Dirac sea are encoded in higher order derivative
terms and multi-fermion interactions with perturbatively calculable, finite
coefficients. Characteristic differences between models with discrete and
continuous chiral symmetry are observed and clarified.


title:
Convergence of products of stochastic matrices with positive diagonals
  and the opinion dynamics background

abstract:
  We present a convergence result for infinite products of stochastic matrices
with positive diagonals. We regard infinity of the product to the left. Such a
product converges partly to a fixed matrix if the minimal positive entry of
each matrix does not converge too fast to zero and if either zero-entries are
symmetric in each matrix or the length of subproducts which reach the maximal
achievable connectivity is bounded.
  Variations of this result have been achieved independently in Lorenz 2005,
Moreau 2005 and Hendrickx 2005. We present briefly the opinion dynamics
context, discuss the relations to infinite products where infinity is to the
right (inhomogeneous Markov processes) and present a small improvement and
sketch another.


title:
Phase diagram of a Bose-Fermi mixture in a one-dimensional optical
  lattice in terms of fidelity and entanglement

abstract:
  We study the ground-state phase diagram of a Bose-Fermi mixture loaded in a
one-dimensional optical lattice by computing the ground-state fidelity and
quantum entanglement. We find that the fidelity is able to signal quantum phase
transitions between the Luttinger liquid phase, the density-wave phase, and the
phase separation state of the system; and the concurrence can be used to signal
the transition between the density-wave phase and the Ising phase.


title: A physical basis for MOND

abstract:
  MOND is a phenomenological theory with no apparent physical justification
which seems to undermine some of the basic principles that underpin established
theoretical physics. It is nevertheless remarkably successful over its sphere
of application and this suggests MOND may have some physical basis. It is shown
here that two simple axioms pertaining to fundamental principles will reproduce
the characteristic behaviour of MOND, though the axioms are in conflict with
general relativistic cosmology.


title: Curved Casimir Operators and the BGG Machinery

abstract:
  We prove that the Casimir operator acting on sections of a homogeneous vector
bundle over a generalized flag manifold naturally extends to an invariant
differential operator on arbitrary parabolic geometries. We study some
properties of the resulting invariant operators and compute their action on
various special types of natural bundles. As a first application, we give a
very general construction of splitting operators for parabolic geometries. Then
we discuss the curved Casimir operators on differential forms with values in a
tractor bundle, which nicely relates to the machinery of BGG sequences. This
also gives a nice interpretation of the resolution of a finite dimensional
representation by (spaces of smooth vectors in) principal series
representations provided by a BGG sequence.


title:
Point Mutations Effects on Charge Transport Properties of the
  Tumor-Suppressor Gene p53

abstract:
  We report on a theoretical study of point mutations effects on charge
transfer properties in the DNA sequence of the tumor-suppressor p53 gene. On
the basis of effective single-strand or double-strand tight-binding models
which simulate hole propagation along the DNA, a statistical analysis of charge
transmission modulations associated with all possible point mutations is
performed. We find that in contrast to non-cancerous mutations, mutation
hotspots tend to result in significantly weaker {\em changes of transmission
properties}. This suggests that charge transport could play a significant role
for DNA-repairing deficiency yielding carcinogenesis.


title: Topology of Smectic Order on Compact Substrates

abstract:
  Smectic orders on curved substrates can be described by differential forms of
rank one (1-forms), whose geometric meaning is the differential of the local
phase field of density modulation. The exterior derivative of 1-form is the
local dislocation density. Elastic deformations are described by superposition
of exact differential forms. Applying this formalism to study smectic order on
torus as well as on sphere, we find that both systems exhibit many
topologically distinct low energy states, that can be characterized by two
integer topological charges. The total number of low energy states scales as
the square root of the substrate area. For smectic on a sphere, we also explore
the motion of disclinations as possible low energy excitations, as well as its
topological implications.


title:
Pseudo-periodicity and 1/f noise from the sum of similar intermittent
  signals

abstract:
  The usual interpretation of noise is represented by a sum of many independent
two-level elementary random signals with a distribution of relaxation times. In
this paper it is demonstrated that also the superposition of many similar
single-sided two-level signals, with the same relaxation time, produces noise.
This is possible tanks to the coincidences among the signals which introduce
cross-correlations and tune locally the resulting process in trains of
pseudo-periodic pulses. Computer simulations demonstrate the reliability of
this model, which permits to insert in an coherent framework other models
solving problems still open.


title: Unitarity in the Brout-Englert-Higgs Mechanism for Gravity

abstract:
  Just like the vector bosons in Abelian and non-Abelian gauge theories,
gravitons can attain mass by spontaneous local symmetry breaking. The question
is whether this can happen in a Lorentz-invariant way. We consider the use of
four scalar fields that break coordinate reparametrization invariance, by
playing the role of preferred flat coordinates x, y, z, and t. In the unbroken
representation, the theory has a (negative) cosmological constant, which is
tuned to zero by the scalars in the broken phase. Massive spin 2 bosons and a
single massive scalar survive. The theory is not renormalizable, so at best it
can be viewed as an effective field theory for massive spin 2 particles. One
may think of applications in cosmology, but a more tantalizing idea is to apply
it to string theory approaches to QCD: if the gluon sector is to be described
by a compactified 26 or 10 dimensional bosonic string theory, then the ideas
considered here could be used to describe the mechanism that removes a massless
or tachyonic scalar and provides mass to the spin 2 glueball states. The
delicate problem of removing indefinite metric and/or negative energy states is
addressed. The scalar particle has negative metric, so that unitarity demands
that only states with an even number of them are allowed. Various ways are
considered to adapt the matter section of the theory such that matter only
couples to positive metric states, and we succeed in suppressing the main
contributions to unitarity-violating amplitudes, but the exact restoration of
unitarity in the spinless sector will continue to be a delicate issue in
theories of this sort.


title: Nucleosynthesis from massive stars 50 years after B2FH

abstract:
  We review some important observed properties of massive stars. Then we
discuss how mass loss and rotation affect their evolution and help in giving
better fits to observational constraints. Consequences for nucleosynthesis at
different metallicities are discussed. Mass loss appear to be the key feature
at high metallicity, while rotation is likely dominant at low and very low
metallicities. We discuss various indications supporting the view that very
metal poor stars had their evolution strongly affected by rotational mixing.
Many features, like the origin of primary nitrogen at low metallicity, that of
the C-rich extremely metal poor halo stars, of He-rich stars in massive
globular clusters, of the O-Na anticorrelation in globular clusters may be
related to the existence of a population of very fast rotating metal poor stars
that we tentatively call the {\it spinstars}. A fraction of these {\it
spinstars} may also be the progenitors of GRB in very metal poor regions. They
may avoid pair instability explosion due to the heavy mass loss undergone
during their early evolutionary phases and be, dependent on their frequency,
important sources of ionising photons in the early Universe.


title: Pinch Points and Kasteleyn Transitions: How Spin Ice Changes its Entropy

abstract:
  Complex disordered states - from liquids and glasses to exotic quantum matter
- are ubiquitous in nature. Their key properties include finite entropy,
power-law correlations and emergent organising principles. In spin ice, spin
correlations are determined by an ice rules organising principle that
stabilises a magnetic state with the same zero point entropy as water ice. The
entropy can be manipulated with great precision by a magnetic field: with field
parallel to the trigonal axis one obtains quasi two dimensional kagome ice
which can be mapped onto a dimer model. Here we use a field tilted slightly
away from the trigonal axis to control the dimer statistical weights and
realise the unusual critical behaviour predicted by Kasteleyn. Neutron
scattering on Ho2Ti2O7 reveals pinch point scattering that characterises the
emergent gauge structure of kagome ice; diffuse peaks that shift with field,
signaling the Kasteleyn physics; and an unusual critical point.