title:
An infrared-submillimeter study of star-forming regions selected by the
  ISOSS 170um survey

abstract:
  Using the ISOPHOT Serendipity Survey (ISOSS) at 170um a sample of galactic
star-forming regions exhibiting very cold dust temperatures (< 20 K) and high
masses (> 100 M_sun) has been established. We characterise the star-forming
content of five regions that were selected as potential sites for early stage
high-mass star formation using SCUBA (JCMT) and Spitzer observations. In every
region we identify one to four submillimeter clumps with projected sizes
between 0.1 and 0.4 pc. The dust temperatures range from 11.6 to 21.3 K and the
estimated clump masses are 2 to 166 M_sun. Towards the majority of
submillimeter peaks we find point sources in the near- to mid-infrared. Most
are interpreted as low-mass young stellar objects but we also detect very red
sources. They probably represent very young and deeply embedded protostars that
continue to accrete clump material and may reach higher masses. Several
candidate intermediate-mass proto- or pre-main-sequence stars embedded in the
clumps are identified. A subset of four clumps may be massive enough (> 100
M_sun) to form high-mass stars and accompanying clusters. The absence of
stellar precursors with current masses in the high-mass regime leave the type
of star formation occuring in the clumps unsettled. We confirm the presence of
large fractions of cold material as derived from large-scale far-infrared
measurements which dominates the emission of most clumps and suggests that the
star-forming process will continue.


title:
Regularity of non-characteristic minimal graphs in the Heisenberg group
  $H^1$

abstract:
  Minimal surfaces in the sub-Riemannian Heisenberg group can be constructed by
means of a Riemannian approximation scheme, as limit of Riemannian minimal
surfaces. We study the regularity of Lipschitz, non-characteristic minimal
surfaces which arise as such limits. Our main results are a-priori estimates on
the solutions of the approximating Riemannian PDE and the ensuing $C^{\infty}$
regularity of the sub-Riemannian minimal surface along its Legendrian
foliation.


title: Uniqueness and Stability in $\mathcal E(X,\omega)$

abstract:
  We prove uniqueness for the Dirichlet problem for the complex Monge-Amp\`ere
equation on compact K\"ahler manifolds in the case of measures vanishing on
pluripolar sets. As a by-product we generalize Xing's stability theorem.


title:
Smoothness of Lipschitz minimal intrinsic graphs in Heisenberg groups
  $H^n, n>1$

abstract:
  We prove that Lipschitz intrinsic graphs in the Heisenberg groups $H^n$, with
$n>1$, which are vanishing viscosity solutions of the minimal surface equation
are smooth.


title:
Different Schemes of Neutrino Oscillations in M\"Ossbauer Neutrino
  Experiment

abstract:
  We comment on the paper "On application of the time-energy uncertainty
relation to M\"ossbauer neutrino experiments" (see arXiv: 0803.1424) in which
our paper "Time-energy uncertainty relations for neutrino oscillation and
M\"ossbauer neutrino experiment" (see arXiv: 0803.0527) has been criticized. We
argue that this critique is a result of misinterpretation: The authors of
(arXiv: 0803.1424) do not take into account (or do not accept) the fact that at
present there exist different schemes of neutrino oscillations which can not be
distinguished in usual neutrino oscillation experiments. We stress that a
recently proposed M\"ossbauer neutrino experiment provides the unique
possibility to discriminate basically different approaches to oscillations of
flavor neutrinos.


title:
Redispersible Hybrid Nanopowders: Cerium Oxide Nanoparticle Complexes
  with Phosphonated-PEG Oligomers

abstract:
  Rare earth cerium oxide (ceria) nanoparticles are stabilized using
end-functional phosphonated-PEG oligomers. The complexation process and
structure of the resulting hybrid core-shell singlet nanocolloids are
described, characterized and modeled using light and neutron scattering data.
The adsorption mechanism is non-stoichiometric, yielding the number of adsorbed
chains per particle Nads = 270 at saturation. Adsorption isotherms show a high
affinity of the phosphonate head for the ceria surface (adsorption energy ~ -16
kT) suggesting an electrostatic driving force for the complexation. The ease,
efficiency and integrity of the complexation is highlighted by the formation of
nanometric sized cerium oxide particles covered with a well anchored PEG layer,
maintaining the characteristics of the original sol. This solvating brush-like
layer is sufficient to solubilize the particles and greatly expand the
stability range of the original sol up to pH = 9. We underscore two key
attributes of the tailored sol: i) strong UV absorption capability after
functionalization and ii) ability to re-disperse after freeze-drying as powder
in aqueous or organic solvents in varying concentrations as singlet
nanocolloids. This robust platform enables translation of intrinsic properties
of mineral oxide nanoparticles to critical end use.


title: Random Search Algorithms for the Sparse Null Vector Problem

abstract:
  We consider the following problem: Given a matrix A, find minimal subsets of
columns of A with cardinality no larger than a given bound that are linear
dependent or nearly so. This problem arises in various forms in optimization,
electrical engineering, and statistics. In its full generality, the problem is
known to be NP-complete. We present a Monte Carlo method that finds such
subsets with high confidence. We also give a deterministic method that is
capable of proving that no subsets of linearly dependent columns up to a
certain cardinality exist. The performance of both methods is analyzed and
illustrated with numerical experiments.


title:
Counting statistics for the Anderson impurity model: Bethe ansatz and
  Fermi liquid study

abstract:
  We study the counting statistics of charge transport in the Anderson impurity
model (AIM) employing both Keldysh perturbation theory in a Fermi liquid
picture and the Bethe ansatz. In the Fermi liquid approach, the object of our
principal interest is the generating function for the cumulants of the charge
current distribution. We derive an exact analytic formula relating the full
counting statistic (FCS) generating function to the self-energy of the system
in the presence of a measuring field. We first check that our approach
reproduces correctly known results in simple limits, like the FCS of the
resonant level system (AIM without Coulomb interaction). We then proceed to
study the FCS for the AIM perturbatively in the Coulomb interaction. By
comparing this perturbative analysis with a strong coupling expansion, we
arrive at a conjecture for an expression for the FCS generating function at
O(V^3) (V is the voltage across the impurity) valid at all orders in the
interaction.
  In the second part of the article, we examine a Bethe ansatz analysis of the
current noise for the AIM. Unlike the Fermi liquid approach, here the goal is
to obtain qualitative, not quantitative, results for a wider range of voltages
both in and out of a magnetic field. Particularly notable are finite field
results showing a double peaked structure in the current noise for voltages
satisfying eV ~ mu H$. This double peaked structure is the ``smoking gun'' of
Kondo physics in the current noise and is directly analogous to the single peak
structure predicted for the differential conductance of the AIM.


title:
Robust Machine Learning Applied to Astronomical Datasets III:
  Probabilistic Photometric Redshifts for Galaxies and Quasars in the SDSS and
  GALEX

abstract:
  We apply machine learning in the form of a nearest neighbor instance-based
algorithm (NN) to generate full photometric redshift probability density
functions (PDFs) for objects in the Fifth Data Release of the Sloan Digital Sky
Survey (SDSS DR5). We use a conceptually simple but novel application of NN to
generate the PDFs - perturbing the object colors by their measurement error -
and using the resulting instances of nearest neighbor distributions to generate
numerous individual redshifts. When the redshifts are compared to existing SDSS
spectroscopic data, we find that the mean value of each PDF has a dispersion
between the photometric and spectroscopic redshift consistent with other
machine learning techniques, being sigma = 0.0207 +/- 0.0001 for main sample
galaxies to r < 17.77 mag, sigma = 0.0243 +/- 0.0002 for luminous red galaxies
to r < ~19.2 mag, and sigma = 0.343 +/- 0.005 for quasars to i < 20.3 mag. The
PDFs allow the selection of subsets with improved statistics. For quasars, the
improvement is dramatic: for those with a single peak in their probability
distribution, the dispersion is reduced from 0.343 to sigma = 0.117 +/- 0.010,
and the photometric redshift is within 0.3 of the spectroscopic redshift for
99.3 +/- 0.1% of the objects. Thus, for this optical quasar sample, we can
virtually eliminate 'catastrophic' photometric redshift estimates. In addition
to the SDSS sample, we incorporate ultraviolet photometry from the Third Data
Release of the Galaxy Evolution Explorer All-Sky Imaging Survey (GALEX AIS GR3)
to create PDFs for objects seen in both surveys. For quasars, the increased
coverage of the observed frame UV of the SED results in significant improvement
over the full SDSS sample, with sigma = 0.234 +/- 0.010. We demonstrate that
this improvement is genuine. [Abridged]


title: Feynman parametrization and Mellin summation at finite temperature

abstract:
  We show that the Mellin summation technique (MST) is a well defined and
useful tool to compute loop integrals at finite temperature in the
imaginary-time formulation of thermal field theory, especially when interested
in the infrared limit of such integrals. The method makes use of the Feynman
parametrization which has been claimed to have problems when the analytical
continuation from discrete to arbitrary complex values of the Matsubara
frequency is performed. We show that without the use of the MST, such problems
are not intrinsic to the Feynman parametrization but instead, they arise as a
result of (a) not implementing the periodicity brought about by the possible
values taken by the discrete Matsubara frequencies before the analytical
continuation is made and (b) to the changing of the original domain of the
Feynman parameter integration, which seemingly simplifies the expression but in
practice introduces a spurious endpoint singularity. Using the MST, there are
no problems related to the implementation of the periodicity but instead, care
has to be taken when the sum of denominators of the original amplitude
vanishes. We apply the method to the computation of loop integrals appearing
when the effects of external weak magnetic fields on the propagation of scalar
particles is considered.


title:
Dynamic Jahn-Teller effect in electron transport through single C60
  molecules

abstract:
  Scanning tunneling spectra on single C60 molecules that are sufficiently
decoupled from the substrate exhibit a characteristic fine structure, which is
explained as due to the dynamic Jahn-Teller effect. Using electron-phonon
couplings extracted from density functional theory we calculate the tunneling
spectrum through the C60- anionic state and find excellent agreement with
measured data.


title:
Voyage by Catamaran: Effecting Semantic Network "Bricolage" via
  Infinite-Dimensional Zero-Divisor Ensembles

abstract:
  Continuing arguments presented [1] or announced [2][3] in "Complex Systems,"
zero-divisor (ZD) foundations for "scale-free" networks (evinced, in
particular, in the "fractality" of the Internet) are decentralized. Spandrels,
quartets of ZD-free or "hidden" box-kite-like structures (HBKs) in the 2^(N+1)-
ions, are "exploded" from (and uniquely linked to) each standard box-kite in
the 2^N-ions, N > 3. Any HBK houses, in a "cowbird's nest," exactly one copy of
the (ZD-free) octonions, the recursive basis for all ZD ensembles. Each is a
potential waystation for alien-ensemble infiltration in the large, or
metaphor-like jumps in the small. Cowbirding models what evolutionary
biologists [4], and structural mythologist Claude Levi-Strauss before them [5],
term bricolage: the opportunistic co-opting of objects designed for one purpose
to serve others unrelated to it. Such arguments entail switching focus, from
the octahedral box-kite's four triangular "sails," to its trio of square
"catamarans" and their box-kite-switching "twist products."


title: Robust Machine Learning Applied to Terascale Astronomical Datasets

abstract:
  We present recent results from the LCDM (Laboratory for Cosmological Data
Mining; http://lcdm.astro.uiuc.edu) collaboration between UIUC Astronomy and
NCSA to deploy supercomputing cluster resources and machine learning algorithms
for the mining of terascale astronomical datasets. This is a novel application
in the field of astronomy, because we are using such resources for data mining,
and not just performing simulations. Via a modified implementation of the NCSA
cyberenvironment Data-to-Knowledge, we are able to provide improved
classifications for over 100 million stars and galaxies in the Sloan Digital
Sky Survey, improved distance measures, and a full exploitation of the simple
but powerful k-nearest neighbor algorithm. A driving principle of this work is
that our methods should be extensible from current terascale datasets to
upcoming petascale datasets and beyond. We discuss issues encountered to-date,
and further issues for the transition to petascale. In particular, disk I/O
will become a major limiting factor unless the necessary infrastructure is
implemented.


title:
Near-Field Modification of Interference Components in Surface Plasmon
  Resonance

abstract:
  In an attenuated total reflection (ATR) geometry, energy extracted from an
incident light beam by surface plasmon polariton (SPP) creation is implicitly
considered to dissipate as heat. However, we show that a sharpened tip
interacting with the SPP evanescent field can redirect some of the energy
before such dissipation occurs. This behavior is examined with simple computer
simulations and an analogy is drawn between it and a modified Mach-Zehnder
interferometer. We also discuss "interaction-free" measurements with our
set-up.


title: Covering data and higher dimensional global class field theory

abstract:
  For a connected regular scheme X, flat and of finite type over Spec(Z), we
construct a reciprocity homomorphism \rho_X: C_X --> \pi_1^\ab(X), which is
surjective and whose kernel is the connected component of the identity. The
(topological) group C_X is explicitly given and built solely out of data
attached to points and curves on X. A similar but weaker statement holds for
smooth varieties over finite fields. Our results are based on earlier work of
G. Wiesend.


title:
The properties of the putative pulsar associated with IGR
  J18135-1751/HESS J1813-178

abstract:
  Context: We investigate the possible theoretical properties of the putative
pulsar associated with the pulsar wind nebula IGR J18135-1751/HESS J1813-178
based upon recent gamma-ray observations and archival multi-wavelength
observations. Aims: We show that when using the standard equations for magnetic
dipole radiation with recent soft gamma-ray observations leads to deriving an
extreme set of parameters (magnetic field, period and spin down rate) for the
putative pulsar. Alternative scenarios that generate more typical parameter
values are explored. Methods: The properties of the putative pulsar are
calculated assuming that the 20-100 keV luminosity corresponds to 1% of Edot,
that the source is 4.5 kpc away, and that the pulsar age is 300 yrs. This gives
P = 0.55 s, Pdot = 3E-11 s/s, and B = 1.28E14 G. This is a very extreme set
compared to the population of known pulsars in PWN systems. Using the equations
for magnetic dipole losses makes it possible to adjust the initial assumptions
to see what is required for a more reasonable set of pulsar parameters.
Results: The current measured properties for IGR J18135-1751/HESS J1813-178
(i.e. luminosity, distance, and age) result in extreme properties of the unseen
pulsar within the PWN. The simplest method for achieving more reasonable
properties for the pulsar is to decouple the spin-down age of the pulsar from
the actual age for the system.


title: Coalitions in Cooperative Wireless Networks

abstract:
  Cooperation between rational users in wireless networks is studied using
coalitional game theory. Using the rate achieved by a user as its utility, it
is shown that the stable coalition structure, i.e., set of coalitions from
which users have no incentives to defect, depends on the manner in which the
rate gains are apportioned among the cooperating users. Specifically, the
stability of the grand coalition (GC), i.e., the coalition of all users, is
studied. Transmitter and receiver cooperation in an interference channel (IC)
are studied as illustrative cooperative models to determine the stable
coalitions for both flexible (transferable) and fixed (non-transferable)
apportioning schemes. It is shown that the stable sum-rate optimal coalition
when only receivers cooperate by jointly decoding (transferable) is the GC. The
stability of the GC depends on the detector when receivers cooperate using
linear multiuser detectors (non-transferable). Transmitter cooperation is
studied assuming that all receivers cooperate perfectly and that users outside
a coalition act as jammers. The stability of the GC is studied for both the
case of perfectly cooperating transmitters (transferrable) and under a partial
decode-and-forward strategy (non-transferable). In both cases, the stability is
shown to depend on the channel gains and the transmitter jamming strengths.


title: Neutrinos with magnetic moments emit photons into inhomogeneous media

abstract:
  This paper has been withdrawn by the author. The spinor matrix element was
incorrect, and orders of magnitude too big.


title:
Combined CDF and D0 Upper Limits on Standard Model Higgs-Boson
  Production with up to 2.4 fb-1 of data

abstract:
  We combine results from CDF and D0 searches for a standard model Higgs boson
in ppbar collisions at the Fermilab Tevatron at sqrt{s}=1.96 TeV. With 1.0-2.4
fb-1 of data collected at CDF, and 1.1-2.3 fb-1 at D0, the 95 % C.L. upper
limits on Higgs boson production are a factor of 3.7 (1.1) higher than the SM
cross section for a Higgs boson mass of m_{H}=115 (160) GeV. Based on
simulation, the median expected upper limit should be 3.3 (1.6). Standard Model
branching ratios, calculated as functions of the Higgs boson mass, are assumed.
Compared to the previous Higgs Tevatron combination, more data and new channels
(H -> gamma gamma, and $H -> tau tau produced in several modes) have been
added. Existing channels, such as both experiments' ZH -> nu nu b b channels,
have been reanalyzed to gain sensitivity. These results extend significantly
the individual limits of each experiment.


title:
Dynamics of matter-wave solitons in a time-modulated two-dimensional
  optical lattice

abstract:
  By means of the variational approximation (VA) and systematic simulations, we
study dynamics and stability boundaries for solitons in a two-dimensional (2D)
self-attracting Bose-Einstein condensate (BEC), trapped in an optical lattice
(OL) whose amplitude is subjected to the periodic time modulation (the
modulation frequency, $\omega $, may be in the range of several KHz). Regions
of stability of the solitons against the collapse and decay are identified in
the space of the model's parameters. A noteworthy result is that the stability
limit may reach the largest (100%) modulation depth, and the collapse threshold
may exceed its classical value in the static lattice (which corresponds to the
norm of Townes soliton). Minimum norm $% N_{\min}$ necessary for the stability
of the solitons is identified too. It features a strong dependence on $\omega $
at a low frequencies, due to a resonant decay of the soliton. Predictions of
the VA are reasonably close to results of the simulations. In particular, the
VA helps to understand salient resonant features in the shape of the stability
boundaries observed with the variation of $\omega $.


title: The potential impact of groove modes on Type II planetary migration

abstract:
  In this letter, we briefly describe the evolution of a variety of
self-gravitating protoplanetary disk models that contain annular grooves (e.g.
gaps) in their surface density. These grooves are inspired by the density gaps
that are presumed to open in response to the formation of a giant planet. Our
work provides an extension of the previously studied groove modes that are
known in the context of stellar disks. The emergence of spiral gravitational
instabilities (GI) is predicted via a generalized eigenvalue code that performs
a linear analysis, and confirmed with hydrodynamical simulations. We find the
presence of a groove drives a fast-growing two-armed mode in moderately massive
disks, and extends the importance of self-gravitating instabilities down to
lower disk masses than for which they would otherwise occur. We discuss the
potential importance of this instability in the context of planet formation,
e.g. the modification of the torques driving Type II migration.


title: Multifractal analysis of a road-to-crisis in a Faraday experiment

abstract:
  A thin layer of liquid in a horizontal cell is subjected to a periodic
vertical force with two control parameters: acceleration and frequency. The
influence of the rheological behavior of the fluid was considered over the
empirically obtained results, which were subjected to a multfractal spectrum
process. As control parameters varied, so did the corresponding spectra,
according to theoretical models; each change of state was visually detected,
which permitted interpreting the corresponding spectral changes.


title: Stress Tensor for Quantized Random Field and Wave Function Collapse

abstract:
  The continuous spontaneous localization (CSL) theory of dynamical wave
function collapse is an experimentally testable alternative to non-relativistic
quantum mechanics. In it, collapse occurs because particles interact with a
classical random field. However, particles gain energy from this field, i.e.,
particle energy is not conserved. Recently, it has been shown how to construct
a theory dubbed "completely quantized collapse" (CQC) which is predictively
equivalent to CSL. In CQC, a quantized random field is introduced, and CSL's
classical random field becomes its eigenvalue. In CQC, energy is conserved,
which allows one to understand that energy is conserved in CSL, as the
particle's energy gain is compensated by the random field's energy loss. Since
the random field has energy, it should have gravitational consequences. For
that, one needs to know the random field's energy density. In this paper, it is
shown how to construct a symmetric, conserved, energy-momentum-stress-density
tensor associated with the quantized random field, even though this field obeys
no dynamical equation and has no Lagrangian. Then, three examples are given
involving the random field's energy density. One considers interacting
particles, the second treats a "cosmological" particle creation model, the
third involves the gravity of the random field.


title: Role of dipolar correlations in the IR spectra of water and ice

abstract:
  We report simulated infrared spectra of deuterated water and ice using
Car-Parrinello molecular dynamics with maximally localized Wannier functions.
Experimental features are accurately reproduced within the harmonic
approximation. By decomposing the lineshapes in terms of intra and
intermolecular dipole correlation functions we find that short-range
intermolecular dynamic charge fluctuations associated to hydrogen bonds are
prominent over the entire spectral range. Our analysis reveals the origin of
several spectral features and identifies network bending modes in the far IR
range.


title:
Characterizing symmetry breaking patterns in a lattice by dual vortex
  degree of freedoms

abstract:
  A duality transformation in quantum field theory is usually established first
through partition functions. It is always important to explore the dual
relations between various correlation functions in the transformation. Here, we
explore such a dual relation to study quantum phases and phase transitions in
an extended boson Hubbard model at 1/3 (2/3) filling on a triangular lattice.
  We develop systematically a simple and effective way to use the vortex degree
of freedoms on dual lattices to characterize both the density wave and valence
bond symmetry breaking patterns of the boson insulating states in the direct
lattices.
  In addition to a checkerboard charge density wave (X-CDW) and a stripe CDW,
we find a novel CDW-VBS phase which has both local CDW and local valence bond
solid (VBS) orders. Implications on QMC simulations are addressed.
  The possible experimental realizations of cold atoms loaded on optical
lattices are discussed.


title:
Combining Beamforming and Space-Time Coding Using Noisy Quantized
  Feedback

abstract:
  The goal of combining beamforming and space-time coding in this work is to
obtain full-diversity order and to provide additional received power (array
gain) compared to conventional space-time codes. In our system, we consider a
quasi-static fading environment and we incorporate both high-rate and low-rate
feedback channels with possible feedback errors. To utilize feedback
information, a class of code constellations is proposed, inspired from
orthogonal designs and precoded space-time block codes, which is called
generalized partly orthogonal designs or generalized PODs. Furthermore, to
model feedback errors, we assume that the feedback bits go through binary
symmetric channels (BSCs). Two cases are studied: first, when the BSC bit error
probability is known a priori to the transmission ends and second, when it is
not known exactly. In the first case, we derive a minimum pairwise error
probability (PEP) design criterion for generalized PODs. Then we design the
quantizer for the erroneous feedback channel and the precoder codebook of PODs
based on this criterion. The quantization scheme in our system is a channel
optimized vector quantizer (COVQ). In the second case, the design of the
quantizer and the precoder codebook is based on similar approaches, however
with a worst-case design strategy. The attractive property of our combining
scheme is that it converges to conventional space-time coding with low-rate and
erroneous feedback and to directional beamforming with high-rate and error-free
feedback. This scheme shows desirable robustness against feedback channel
modeling mismatch.


title: Scaling in the distribution of intertrade durations of Chinese stocks

abstract:
  The distribution of intertrade durations, defined as the waiting times
between two consecutive transactions, is investigated based upon the limit
order book data of 23 liquid Chinese stocks listed on the Shenzhen Stock
Exchange in the whole year 2003. A scaling pattern is observed in the
distributions of intertrade durations, where the empirical density functions of
the normalized intertrade durations of all 23 stocks collapse onto a single
curve. The scaling pattern is also observed in the intertrade duration
distributions for filled and partially filled trades and in the conditional
distributions. The ensemble distributions for all stocks are modeled by the
Weibull and the Tsallis $q$-exponential distributions. Maximum likelihood
estimation shows that the Weibull distribution outperforms the $q$-exponential
for not-too-large intertrade durations which account for more than 98.5% of the
data. Alternatively, nonlinear least-squares estimation selects the
$q$-exponential as a better model, in which the optimization is conducted on
the distance between empirical and theoretical values of the logarithmic
probability densities. The distribution of intertrade durations is Weibull
followed by a power-law tail with an asymptotic tail exponent close to 3.


title:
Planckian Scattering Beyond the Eikonal Approximation in the
  Quasi-potential Approach

abstract:
  Asymptotic behavior of the scattering amplitude for two scalar particles by
scalar, vector and tensor exchanges at high energy and fixed momentum transfers
is reconsidered in quantum field theory. In the framework of the
quasi-potential approach and the modified perturbation theory a systematic
scheme of finding the leading eikonal scattering amplitudes and its corrections
are developed and constructed. The connection between the solutions obtained by
quasi-potential and functional approaches is also discussed. The first
correction to leading eikonal amplitude is found.


title:
Minimal Standard Model self-energies at finite temperature in the
  presence of weak magnetic fields: towards a full symmetry restoration study

abstract:
  The study of the universe's primordial plasma at high temperature plays an
important role when tackling different questions in cosmology, such as the
origin of the matter-antimatter asymmetry. In the Minimal Standard Model (MSM)
neither the amount of CP violation nor the strength of the phase transition are
enough to produce and preserve baryon number during the Electroweak Phase
Transition (EWPT), which are two of the three ingredients needed to develop
baryon asymmetry. In this talk we present the first part of the analysis done
within a scenario where it is viable to have improvements to the aforementioned
situation: we work with the degrees of freedom in the broken symmetry phase of
the MSM and analyze the development of the EWPT in the presence of a weak
magnetic field. More specifically, we calculate the particle self-energies that
include the effects of the weak magnetic field, needed for the MSM effective
potential up to ring diagrams.


title: Lecture notes on the lambda calculus

abstract:
  This is a set of lecture notes that developed out of courses on the lambda
calculus that I taught at the University of Ottawa in 2001 and at Dalhousie
University in 2007 and 2013. Topics covered in these notes include the untyped
lambda calculus, the Church-Rosser theorem, combinatory algebras, the
simply-typed lambda calculus, the Curry-Howard isomorphism, weak and strong
normalization, polymorphism, type inference, denotational semantics, complete
partial orders, and the language PCF.


title:
Fluctuation Effect in the \pi-flux State for Undoped High-Temperature
  Superconductors

abstract:
  The effect of fluctuations about the pi-flux mean field state for the undoped
high-temperature superconductors is investigated. It is shown that fluctuations
of the mean fields lead to a self-energy correction that doubles the band width
of the fermion dispersion in the lowest order. The dynamical mass generation is
associated with the self-energy effect due to the interaction mediated by the
Lagrange multiplier field, which is introduced to impose the constraint on the
fermions. A self-consistent picture about the mass generation and the prop-
agation of the Lagrange multiplier field without damping is proposed. The
antiferromagnetic long-range ordering is described without introducing an
additional repulsive interaction. The theory suggests a natural framework to
study spin disordered systems in which fermionic excitations are low-lying
excitations.


title:
Effects of the crystal structure on the ferromagnetic correlations in
  ZnO with magnetic impurities

abstract:
  We study the ferromagnetism in the compound (Zn,Mn)O within the
Haldane-Anderson impurity model by using the quantum Monte Carlo technique and
the tight-binding approximation for determining the host band-structure and the
impurity-host hybridization. This computational approach allows us to determine
how the host crystal structure influences the impurity bound state, which plays
an important role in the development of the ferromagnetic (FM) correlations
between the impurities. We find that the FM correlations are strongly
influenced by the crystal structure. In particular, in p-type (Zn,Mn)O, we
observe the development of FM correlations with an extended range at low
temperatures for wurtzite and zincblende crystal structures. However, for the
rocksalt structure no FM correlations are observed between the impurities. In
addition, in n-type ZnO with magnetic impurities, the impurity bound state and
FM correlations are not found.


title: Galactic Halos and Black Holes in Non-Canonical Scalar Field Theories

abstract:
  We consider static spherically symmetric solutions of a general scalar field
theory with non-standard kinetic energy coupled to gravity with a view to
explain dark matter halos as a coherent state of the scalar field. Consistent
solutions are found with a smooth scalar profile which can describe observed
rotation curves. Some of the solutions have negative scalar energy density near
the origin though the total energy is positive definite. The solutions with
positive energy density everywhere have a steeper rotation curve near the
origin than those that don't. We also reconsider the no scalar hair theorems
for black holes with emphasis on asymptotic boundary conditions and
super-luminal propagation. Some modifications and extensions of previous
analyses are discussed.


title: New open string solutions in AdS_5

abstract:
  We describe new solutions for open string moving in AdS_5 and ending in the
boundary, namely dual to Wilson loops in N=4 SYM theory. First we introduce an
ansatz for Euclidean curves whose shape contains an arbitrary function. They
are BPS and the dual surfaces can be found exactly. After an inversion they
become closed Wilson loops whose expectation value is
$W=\exp(-\sqrt{\lambda})$. After that we consider several Wilson loops for N=4
SYM in a pp-wave metric and find the dual surfaces in an AdS_5 pp-wave
background. Using the fact that the pp-wave is conformally flat, we apply a
conformal transformation to obtain novel surfaces describing strings moving in
AdS space in Poincare coordinates and dual to Wilson loops for N=4 SYM in flat
space.


title: Information theoretic bounds for Compressed Sensing

abstract:
  In this paper we derive information theoretic performance bounds to sensing
and reconstruction of sparse phenomena from noisy projections. We consider two
settings: output noise models where the noise enters after the projection and
input noise models where the noise enters before the projection. We consider
two types of distortion for reconstruction: support errors and mean-squared
errors. Our goal is to relate the number of measurements, $m$, and $\snr$, to
signal sparsity, $k$, distortion level, $d$, and signal dimension, $n$. We
consider support errors in a worst-case setting. We employ different variations
of Fano's inequality to derive necessary conditions on the number of
measurements and $\snr$ required for exact reconstruction. To derive sufficient
conditions we develop new insights on max-likelihood analysis based on a novel
superposition property. In particular this property implies that small support
errors are the dominant error events. Consequently, our ML analysis does not
suffer the conservatism of the union bound and leads to a tighter analysis of
max-likelihood. These results provide order-wise tight bounds. For output noise
models we show that asymptotically an $\snr$ of $\Theta(\log(n))$ together with
$\Theta(k \log(n/k))$ measurements is necessary and sufficient for exact
support recovery. Furthermore, if a small fraction of support errors can be
tolerated, a constant $\snr$ turns out to be sufficient in the linear sparsity
regime. In contrast for input noise models we show that support recovery fails
if the number of measurements scales as $o(n\log(n)/SNR)$ implying poor
compression performance for such cases. We also consider Bayesian set-up and
characterize tradeoffs between mean-squared distortion and the number of
measurements using rate-distortion theory.


title: Localization Study of a Non-Local Energetic Damage Model

abstract:
  The contribution presents an analysis of a rate-independent non-local damage
model, recently proposed by (Mielke and Roubicek, 2006). An analytical as well
as numerical solution of a simple one-dimensional bifurcation problem is
performed, demonstrating that, for the elementary localization test, the model
is free of pathological features.


title: A triple quantum dot in a single wall carbon nanotube

abstract:
  A top-gated single wall carbon nanotube is used to define three coupled
quantum dots in series between two electrodes. The additional electron number
on each quantum dot is controlled by top-gate voltages allowing for current
measurements of single, double and triple quantum dot stability diagrams.
Simulations using a capacitor model including tunnel coupling between
neighboring dots captures the observed behavior with good agreement.
Furthermore, anti-crossings between indirectly coupled levels and higher order
cotunneling are discussed.


title: Quantum Feedback Networks: Hamiltonian Formulation

abstract:
  A quantum network is an open system consisting of several component Markovian
input-output subsystems interconnected by boson field channels carrying quantum
stochastic signals. Generalizing the work of Chebotarev and Gregoratti, we
formulate the model description by prescribing a candidate Hamiltonian for the
network including details the component systems, the field channels, their
interconnections, interactions and any time delays arising from the geometry of
the network. (We show that the candidate is a symmetric operator and proceed
modulo the proof of self-adjointness.) The model is non-Markovian for finite
time delays, but in the limit where these delays vanish we recover a Markov
model and thereby deduce the rules for introducing feedback into arbitrary
quantum networks. The type of feedback considered includes that mediated by the
use of beam splitters. We are therefore able to give a system-theoretic
approach to introducing connections between quantum mechanical state-based
input-output systems, and give a unifying treatment using non-commutative
fractional linear, or Mobius, transformations.


title: Geometric variations of the Boltzmann entropy

abstract:
  We perform a calculation of the first and second order infinitesimal
variations, with respect to energy, of the Boltzmann entropy of constant energy
hypersurfaces of a system with a finite number of degrees of freedom. We
comment on the stability interpretation of the second variation in this
framework.

categories: cond-mat.stat-mech gr-qc hep-th math-ph math.MP


title:
Magnetization relaxation in the single molecule magnet Ni$_4$ under
  continuous microwave irradiation

abstract:
  Spin relaxation between the two lowest-lying spin-states has been studied in
the S=4 single molecule magnet Ni$_4$ under steady state conditions of low
amplitude and continuous microwave irradiation. The relaxation rate was
determined as a function of temperature at two frequencies, 10 and 27.8 GHz, by
simultaneously measuring the magnetization and the absorbed microwave power. A
strong temperature dependence is observed below 1.5 K, which is not consistent
with a direct single-spin-phonon relaxation process. The data instead suggest
that the spin relaxation is dominated by a phonon bottleneck at low
temperatures and occurs by an Orbach mechanism involving excited spin-levels at
higher temperatures. Experimental results are compared with detailed
calculations of the relaxation rate using the universal density matrix
equation.


title: Bright flares from the X-ray pulsar SWIFT J1626.6-5156

abstract:
  We have performed a timing and spectral analysis of the X-ray pulsar SWIFT
J1626.6-5156 during a major X-ray outburst in order to unveil its nature and
investigate its flaring activity. Epoch- and pulse-folding techniques were used
to derive the spin period. Time-average and pulse-phase spectroscopy were
employed to study the spectral variability in the flare and out-of-flare states
and energy variations with pulse phase. Power spectra were obtained to
investigate the periodic and aperiodic variability. Two large flares, with a
duration of ~450 seconds were observed on 24 and 25 December 2005. During the
flares, the X-ray intensity increased by a factor of 3.5, while the
peak-to-peak pulsed amplitude increased from 45% to 70%. A third, smaller flare
of duration ~180 s was observed on 27 December 2005. The flares seen in SWIFT
J1626.6-5156 constitute the shortest events of this kind ever reported in a
high-mass X-ray binary. In addition to the flaring activity, strong X-ray
pulsations with Pspin=15.3714+-0.0003 s characterise the X-ray emission in
SWIFT J1626.6-5156. After the major outburst, the light curve exhibits strong
long-term variations modulated with a 45-day period. We relate this modulation
to the orbital period of the system or to a harmonic. Power density spectra
show, in addition to the harmonic components of the pulsation, strong
band-limited noise with an integrated 0.01-100 Hz fractional rms of around 40%
that increased to 64% during the flares. A weak QPO (fractional rms 4.7%) with
characteristic frequency of 1 Hz was detected in the non-flare emission. The
timing (short X-ray pulsations, long orbital period) and spectral (power-law
with cut off energy and neutral iron line) properties of SWIFT J1626.6-5156 are
characteristic of Be/X-ray binaries.


title: Low Energy Pion-Pion Elastic Scattering in Sakai-Sugimoto Model

abstract:
  We have considered the holographic large $N_c$ QCD model proposed by Sakai
and Sugimoto and evaluated the non-Abelian DBI-action on the D8-brane upto
$(\alpha')^4$ terms. Restricting to the pion sector, these corrections give
rise to four derivative contact terms for the pion field. We derive the
Weinberg's phenemenological lagrangian. The coefficients of the four derivative
terms are determined in terms of $g_{YM}^2$. The low energy pion-pion
scattering amplitudes are evaluated. Numerical results are presented with the
choice of $M_{KK}=0.94 GeV$ and $N_c=11$. The results are compared with the
amplitudes calculated using the experimental phase shifts. The agreement with
the experimental data is found to be satisfactory.


title: A family of 2-graphs arising from two-dimensional subshifts

abstract:
  Higher-rank graphs (or $k$-graphs) were introduced by Kumjian and Pask to
provide combinatorial models for the higher-rank Cuntz-Krieger $C^*$-algebras
of Robertson and Steger. Here we consider a family of finite 2-graphs whose
path spaces are dynamical systems of algebraic origin, as studied by Schmidt
and others. We analyse the $C^*$-algebras of these 2-graphs, find criteria
under which they are simple and purely infinite, and compute their $K$-theory.
We find examples whose $C^*$-algebras satisfy the hypotheses of the
classification theorem of Kirchberg and Phillips, but are not isomorphic to the
$C^*$-algebras of ordinary directed graphs.


title:
Overdensity of i'-Dropout Galaxies in the Subaru Deep Field: A Candidate
  Protocluster at z ~ 6

abstract:
  We investigate the sky distribution of z ~ 6 Lyman break galaxies selected as
i'-dropouts having i' - z' > 1.45 down to z' < 26.5 in the Subaru Deep Field
(SDF). We discover 37 i'-dropouts clustered in a projected comoving 21.6 x 21.6
Mpc^2 region at z = 6, showing a local density excess. Carrying out follow-up
spectroscopy, we identify four of them as Lyman-alpha emitters at z = 5.92,
6.01, 6.03 and 6.03 (spread over a distance of 46.6 Mpc). The number density of
the cluster itself in SDF is ~ 2.2 x 10^{-7} Mpc^{-3}, smaller than those of
protoclusters (i.e., forming galaxy clusters) at z ~ 2-5.7. Also, the structure
shows ~4-21 times larger galaxy number density than those of z ~ 6 galaxies in
a general field. It has a mass of M ~ 1.5^{+1.8}_{-0.5} x 10^{15}M_sun,
comparable to those of z ~ 0-5 protoclusters. Since the contamination of our
sample by interlopers is estimated to be quite low, 5.9%, most of the other
unconfirmed i'-dropouts in the overdense region can be also z ~ 6 galaxies.
Hence, it could be a candidate forming cluster at z ~ 6, representing a
progenitor of galaxy clusters seen in the recent-day Universe.


title: Noether symmetry in $f(R)$ cosmology

abstract:
  The Noether symmetry of a generic $f(R)$ cosmological model is investigated
by utilizing the behavior of the corresponding Lagrangian under the
infinitesimal generators of the desired symmetry. We explicitly calculate the
form of $f(R)$ for which such symmetries exist. It is shown that the resulting
form of $f(R)$ yields a power law expansion for the cosmological scale factor.
We also obtain the effective equation of state parameter for the corresponding
cosmology and show that our model can provide a gravitational alternative to
the quintessence.


title: Review of Scalar Mesons

abstract:
  The formulae needed to parametrise sigma, kappa, a0(980) and f0(980) are
reviewed. For sigma and kappa, the Adler zero due to Chiral Symmetry Breaking
plays a crucial role. The f0(980) and a0(980) are locked to the KK threshold by
a cusp mechanism which leads to a sharp peak in attraction at the threshold.
This mechanism may play a wider role. A novel suggestion is that the
confinement potential involves a cooperative effect between QCD effects
(coloured quarks and gluons) and conventional meson exchanges.


title: Functional calculus extensions on dual spaces

abstract:
  In this note, we show that if a Banach space X has a predual, then every
bounded linear operator on X with a continuous functional calculus admits a
bounded Borel functional calculus. A consequence of this is that on such a
Banach space, the classes of finitely spectral and prespectral operators
coincide. We also apply this result to give some sufficient conditions for an
operator with an absolutely continuous functional calculus to admit a bounded
Borel one.


title:
Stable Cohomotopy Seiberg-Witten Invariants of Connected Sums of
  Four-Manifolds with Positive First Betti Number

abstract:
  We shall prove a new non-vanishing theorem for the stable cohomotopy
Seiberg-Witten invariant of connected sums of 4-manifolds with positive first
Betti number. The non-vanishing theorem enables us to find many new examples of
4-manifolds with non-trivial stable cohomotopy Seiberg-Witten invariants and it
also gives a partial, but strong affirmative answer to a conjecture concerning
non-vanishing of the invariant. Various new applications of the non-vanishing
theorem are also given. For example, we shall introduce variants
$\bar{\lambda}_k$ of Perelman's $\bar{\lambda}$ invariants for real numbers $k$
and compute the values for a large class of 4-manifolds including connected
sums of certain K{\"{a}}hler surfaces. The non-vanishing theorem is also used
to construct the first examples of 4-manifolds with non-zero simplicial volume
and satisfying the strict Gromov-Hitchin-Thorpe inequality, but admitting
infinitely many distinct smooth structures for which no compatible Einstein
metric exists. Moreover, we are able to prove a new result on the existence of
exotic smooth structures.


title:
Weighted Sum Rate Optimization for Cognitive Radio MIMO Broadcast
  Channels

abstract:
  In this paper, we consider a cognitive radio (CR) network in which the
unlicensed (secondary) users are allowed to concurrently access the spectrum
allocated to the licensed (primary) users provided that their interference to
the primary users (PUs) satisfies certain constraints. We study a weighted sum
rate maximization problem for the secondary user (SU) multiple input multiple
output (MIMO) broadcast channel (BC), in which the SUs have not only the sum
power constraint but also interference constraints. We first transform this
multi-constraint maximization problem into its equivalent form, which involves
a single constraint with multiple auxiliary variables. Fixing these multiple
auxiliary variables, we propose a duality result for the equivalent problem.
Our duality result can solve the optimization problem for MIMO-BC with multiple
linear constraints, and thus can be viewed as an extension of the conventional
results, which rely crucially on a single sum power constraint. Furthermore, we
develop an efficient sub-gradient based iterative algorithm to solve the
equivalent problem and show that the developed algorithm converges to a
globally optimal solution. Simulation results are further provided to
corroborate the effectiveness of the proposed algorithm.


title:
Electron gas at the interface between two antiferromagnetic insulating
  manganites

abstract:
  We study theoretically the magnetic and electric properties of the interface
between two antiferromagnetic and insulating manganites: La0.5Ca0.5MnO3, a
strong correlated insulator, and CaMnO3, a band-insulator. We find that a
ferromagnetic and metallic electron gas is formed at the interface between the
two layers. We confirm the metallic character of the interface by calculating
the in-plane conductance. The possibility of increasing the electron gas
density by selective doping is also discussed.


title: Chemical Analyses of Silicon Aerogel Samples

abstract:
  After five years of operating, two Aerogel counters: A1 and A2, taking data
in Hall A at Jefferson Lab, suffered a loss of performance. In this note
possible causes of degradation have been studied. In particular, various
chemical and physical analyses have been carried out on several Aerogel tiles
and on adhesive tape in order to reveal the presence of contaminants.


title:
Memory Effect in the Photoinduced Femtosecond Rotation of Magnetization
  in the Ferromagnetic Semiconductor GaMnAs

abstract:
  We report a femtosecond response in photoinduced magnetization rotation in
the ferromagnetic semiconductor GaMnAs, which allows for detection of a
four-state magnetic memory at the femtosecond time scale. The temporal profile
of this cooperative magnetization rotation exhibits a discontinuity that
reveals two distinct temporal regimes, marked by the transition from a highly
non-equilibrium, carrier-mediated regime within the first 200 fs, to a thermal,
lattice-heating picosecond regime.


title: Detecting modules in dense weighted networks with the Potts method

abstract:
  We address the problem of multiresolution module detection in dense weighted
networks, where the modular structure is encoded in the weights rather than
topology. We discuss a weighted version of the q-state Potts method, which was
originally introduced by Reichardt and Bornholdt. This weighted method can be
directly applied to dense networks. We discuss the dependence of the resolution
of the method on its tuning parameter and network properties, using sparse and
dense weighted networks with built-in modules as example cases. Finally, we
apply the method to data on stock price correlations, and show that the
resulting modules correspond well to known structural properties of this
correlation network.


title: Dissipative hydrodynamics and heavy ion collisions

abstract:
  Space-time evolution and subsequent particle production from minimally
viscous ($\eta/s$=0.08) QGP fluid is studied using the 2nd order
Israel-Stewart's theory of dissipative relativistic fluid. Compared to ideal
fluid, energy density or temperature evolves slowly in viscous dynamics.
Particle yield at high $p_T$ is increased. Elliptic flow on the other hand
decreases in viscous dynamics. Minimally viscous QGP fluid found to be
consistent with a large number of experimental data.


title: Towards a stable definition of Kolmogorov-Chaitin complexity

abstract:
  Although information content is invariant up to an additive constant, the
range of possible additive constants applicable to programming languages is so
large that in practice it plays a major role in the actual evaluation of K(s),
the Kolmogorov-Chaitin complexity of a string s. Some attempts have been made
to arrive at a framework stable enough for a concrete definition of K,
independent of any constant under a programming language, by appealing to the
"naturalness" of the language in question. The aim of this paper is to present
an approach to overcome the problem by looking at a set of models of
computation converging in output probability distribution such that that
"naturalness" can be inferred, thereby providing a framework for a stable
definition of K under the set of convergent models of computation.


title:
Density functional study of oxygen vacancies at the SnO2 surface and
  subsurface sites

abstract:
  Oxygen vacancies at the SnO2(110) and (101) surface and subsurface sites have
been studied in the framework of density functional theory by using both
all-electron Gaussian and pseudopotential plane-wave methods. The all-electron
calculations have been performed using the B3LYP exchange-correlation
functional with accurate estimations of energy gaps and density of states. We
show that bulk oxygen vacancies are responsible for the appearance of a fully
occupied flat energy level lying at about 1 eV above the top valence band, and
an empty level resonant with the conduction band. Surface oxygen vacancies
strongly modify the surface band structures with the appearance of intragap
states covering most of the forbidden energy window, or only a small part of
it, depending on the vacancy depth from the surface. Oxygen vacancies can
account for electron affinity variations with respect to the stoichiometric
surfaces as well. A significant support to the present results is found by
comparing them to the available experimental data.


title:
Permutation-invariant monotones for multipartite entanglement
  characterization

abstract:
  In this work we consider the permutational properties of multipartite
entanglement monotones. Based on the fact that genuine multipartite
entanglement is a property of the entire multi-qubit system, we argue that
ideal definitions for its characterizing quantities must be
permutation-invariant. Using this criterion, we examine the three 4-qubit
entanglement monotones introduced by Osterloh and Siewert [Phys. Rev. A. 72,
012337]. By expressing them in terms of quantities whose permutational
properties can be easily derived, we find that one of these monotones is not
permutation-invariant. We propose a permutation-invariant entanglement monotone
to replace it, and show that our new monotone properly measures the genuine
4-qubit entanglement in 4-qubit cluster-class states. Our results provide some
useful insights in understanding multipartite entanglement.


title:
Number Density Evolution of Ks -band Selected High Redshift Galaxy
  Populations in the AKARI North Ecliptic Pole Field

abstract:
  We present the number counts of Ks-band selected high redshift galaxy
populations such as extremely red objects (EROs), B, z & K -band selected
galaxies (BzKs) and distant red galaxies (DRGs) in the AKARI NEP field. The
final catalogue contains 308 EROs (Ks<19.0 ; 54 percent are dusty star-forming
EROs and the rest are passive old EROs), 137 star-forming BzKs and 38 passive
old BzKs (Ks<19.0) and 64 DRGs (Ks<18.6). We also produce individual component
source counts for both the dusty star-forming and passive populations. We
compare the observed number counts of the high redshift passively evolving
galaxy population with a backward pure luminosity evolution (PLE) model
allowing different degrees of number density evolution. We find that the PLE
model without density evolution fails to explain the observed counts at faint
magnitudes, while the model incorporating negative density evolution is
consistent with the observed counts of the passively evolving population. We
also compare our observed counts of dusty star-forming EROs with a
phenomenological evolutionary model postulating that the near-infrared EROs can
be explained by the source densities of the far-infrared - submillimetre
populations. Our model predicts that the dusty ERO source counts can be
explained assuming a 25 percent contribution of submillimetre star-forming
galaxies with the majority of brighter Ks -band detected dusty EROs having
luminous (rather than HR10 type ultra-luminous) submillimetre counterparts. We
propose that the fainter Ks>19.5 population is dominated by the sub-millijansky
submillimetre population. We also predict a turnover in in dusty ERO counts
around 19<Ks<20.


title:
The spectral and temporal properties of an Ultra-Luminous X-ray source
  in NGC 6946

abstract:
  We report variability of the X-ray source, X-7, in NGC 6946, during a 60 ksec
Chandra observation when the count rate decreased by a factor of ~1.5 in ~5000
secs. Spectral fitting of the high and low count rate segments of the light
curve reveal that the simplest and most probable interpretation is that the
X-ray spectra are due to disk black body emission with an absorbing hydrogen
column density equal to the Galactic value of 2.1 X 10^{21} cm^{-2}. During the
variation, the inner disk temperature decreased from ~0.29 to ~0.26 keV while
the inner disk radius remained constant at ~6 X 10^8 cm. This translates into a
luminosity variation from 3.8 to 2.8 X 10^{39} ergs cm^{-2} sec^{-1} and a
black hole mass of ~400 solar masses. More complicated models like assuming
intrinsic absorption and/or the addition of a power-law component imply a
higher luminosity and a larger black hole mass. Even if the emission is beamed
by a factor of ~5, the size of the emitting region would be > 2.7 X 10^8 cm
implying a black hole mass > 180 solar masses. Thus, these spectral results
provide strong evidence that the mass of the black hole in this source is
definitely > 100 solar masses and more probably ~400 solar masses.


title: The basic bundle gerbe on unitary groups

abstract:
  We consider the construction of the basic bundle gerbe on SU(n) introduced by
Meinrenken and show that it extends to a range of groups with unitary actions
on a Hilbert space including U(n), diagonal tori and the Banach Lie group of
unitary operators differing from the identity by an element of a Schatten
ideal. In all these cases we give an explicit connection and curving on the
basic bundle gerbe and calculate the real Dixmier-Douady class. Extensive use
is made of the holomorphic functional calculus for operators on a Hilbert
space.


title: The close-in companion of the fast rotating Be star Achernar

abstract:
  Context: Be stars are massive dwarf or subgiant stars that present temporary
emission lines in their spectrum, and particularly in the Halpha line. The
mechanism triggering these Be episodes is currently unknown, but binarity could
play an important role. Aims: Previous observations with the VLT/VISIR
instrument (Kervella & Domiciano de Souza 2007) revealed a faint companion to
Achernar, the brightest Be star in the sky. The present observations are
intended to characterize the physical nature of this object. Methods: We
obtained near-IR images and an H-band spectrum of Achernar B using the VLT/NACO
adaptive optics systems. Results: Our images clearly show the displacement of
Achernar B over a portion of its orbit around Achernar A. Although these data
are insuficient to derive the orbital parameters, they indicate a period of the
order of 15 yr. The projected angular separation of the two objects in December
2007 was smaller than 0.15 arcsec, or 6.7 AU at the distance of Achernar.
Conclusions: From its flux distribution in the near- and thermal-IR, Achernar B
is most likely an A1V-A3V star. Its orbital period appears similar to the
observed pseudo-periodicity of the Be phenomenon of Achernar. This indicates
that an interaction between A and B at periastron could be the trigger of the
Be episodes.


title: A Holographic Superconductor in an External Magnetic Field

abstract:
  We study a system of a complex charged scalar coupled to a Reissner-Nordstrom
black hole in 3+1 dimensional anti-de Sitter spacetime, neglecting
back-reaction. With suitable boundary conditions, the cases of a neutral and
purely electric black hole have been studied in various limits and were shown
to yield key elements of superconductivity in the dual 2+1 dimensional field
theory, forming a condensate below a critical temperature. By adding magnetic
charge to the black hole, we immerse the superconductor into an external
magnetic field. We show that a family of condensates can form and we examine
their structure. For finite magnetic field, they are localized in one dimension
with a profile that is exactly solvable, since it maps to the quantum harmonic
oscillator. As the magnetic field increases, the condensate shrinks in size,
which is reminiscent of the Meissner effect.


title:
Fast simulation of the whole-sky CMB map in the presence of primordial
  magnetic field

abstract:
  We present a novel method for generation of sets of the Cosmic Microwave
Background (CMB) anisotropy maps, which reproduces the $\Delta \l=2$
correlations associated with Alfv\'en turbulence. The method is based on the
non-linear transformation of the CMB maps, which is obtained from the Monte
Carlo simulation of the statistically isotropic Gaussian signal. Our method is
computationally fast and efficient.
  We have applied two estimators (the cross-correlation estimator in multipole
domain for $\l+1,m$ and $\l-1,m$ modes and circular phase moments) to test the
statistical properties of derived maps. Both of these statistics confirm the
effectiveness of our generation method. We believe that our method can be
useful for fast generation of the non-Gaussian maps in the presence of the
primordial magnetic field, and be a valuable tool for the non-Gaussianity
investigation of the CMB in the framework of the future PLANCK data analysis.


title: Dynamical friction of radio galaxies in galaxy clusters

abstract:
  The distribution of luminous radio galaxies in galaxy clusters has been
observed to be concentrated in the inner region. We consider the role of
dynamical friction of massive galaxies ($M\sim 10^{12.5}$ M$_{\odot}$),
assuming them to be hosts of luminous radio galaxies, and show that beginning
with a Navarro-Frenk-White density profile of a cluster of mass $M_{cl}\sim
10^{15}$ M$_{\odot}$ of concentration $c\sim 5$ and collapsing at $z\sim 1$,
the density profile of radio galaxies evolve to a profile of concentration $c
\sim 25$, as observed, in a time scale of $t\sim 3\hbox{--}5$ Gyr.


title: Boundary Correlators in Supergroup WZNW Models

abstract:
  We investigate correlation functions for maximally symmetric boundary
conditions in the WZNW model on GL(1|1). Special attention is payed to volume
filling branes. Generalizing earlier ideas for the bulk sector, we set up a
Kac-Wakimoto-like formalism for the boundary model. This first order formalism
is then used to calculate bulk-boundary 2-point functions and the boundary
3-point functions of the model. The note ends with a few comments on
correlation functions of atypical fields, point-like branes and generalizations
to other supergroups.


title:
Single-field inflation, anomalous enhancement of superhorizon
  fluctuations, and non-Gaussianity in primordial black hole formation

abstract:
  We show a text-book potential for single-field inflation, namely, the
Coleman-Weinberg model can induce double inflation and formation of primordial
black holes (PBHs), because fluctuations that leave the horizon near the end of
first inflation are anomalously enhanced at the onset of second inflation when
the time-dependent mode turns to a growing mode rather than a decaying mode.
The mass of PBHs produced in this mechanism lies in several discrete ranges
depending on the model parameters. We also calculate the effects of
non-Gaussian statistics due to higher-order interactions on the abundance of
PBHs, which turns out to be small.


title:
A new measurement of the evolving near-infrared galaxy luminosity
  function out to z~4: a continuing challenge to theoretical models of galaxy
  formation

abstract:
  We present the most accurate measurement to date of cosmological evolution of
the near-infrared galaxy luminosity function, from the local Universe out to
z~4. The analysis is based on a large and highly complete sample of galaxies
selected from the first data release of the UKIDSS Ultra Deep Survey.
Exploiting a master catalogue of K- and z-band selected galaxies over an area
of 0.7 square degrees, we analyse a sample of ~50,000 galaxies, all with
reliable photometry in 16-bands from the far-ultraviolet to the mid-infrared.
The unique combination of large area and depth provided by the Ultra Deep
Survey allows us to trace the evolution of the K-band luminosity function with
unprecedented accuracy. In particular, via a maximum likelihood analysis we
obtain a simple parameterization for the luminosity function and its
cosmological evolution, including both luminosity and density evolution, which
provides an excellent description of the data from z =0 up to z~4. We find
differential evolution for galaxies dependent on galaxy luminosity, revealing
once again the ``down-sizing behaviour'' of galaxy formation. Finally, we
compare our results with the predictions of the latest theoretical models of
galaxy formation, based both on semi-analytical prescriptions, and on full
hydrodynamical simulations.


title: Dust sputtering by Reverse Shocks in Supernova Remnants

abstract:
  We consider sputtering of dust grains, believed to be formed in cooling
supernovae ejecta, under the influence of reverse shocks. In the regime of
self-similar evolution of reverse shocks, we can follow the evolution of ejecta
density and temperature analytically as a function of time in different parts
of the ejecta, and calculate the sputtering rate of graphite and silicate
grains embedded in the ejecta as they encounter the reverse shock. Through
analytic (1D) calculations, we find that a fraction of dust mass ($
1\hbox{--}20$% for silicates and %$\le 5$% for graphites) can be sputtered by
reverse shocks, the fraction varying with the grain size distribution and the
steepness of the density profile of the ejecta mass. It is expected that many
more grains will get sputtered in the region between the forward and reverse
shocks, so that our analytical results provide a lower limit to the destroyed
fraction of dust mass.


title: Primordial magnetic fields and formation of molecular hydrogen

abstract:
  We study the implications of primordial magnetic fields for the thermal and
ionization history of the post-recombination era. In particular we compute the
effects of dissipation of primordial magnetic fields owing to ambipolar
diffusion and decaying turbulence in the intergalactic medium (IGM) and the
collapsing halos and compute the effects of the altered thermal and ionization
history on the formation of molecular hydrogen. We show that, for magnetic
field strengths in the range $2 \times 10^{-10} {\rm G} \la B_0 \la 2 \times
10^{-9} {\rm G}$, the molecular hydrogen fraction in IGM and collapsing halo
can increase by a factor 5 to 1000 over the case with no magnetic fields. We
discuss the implication of the increased molecular hydrogen fraction on the
radiative transfer of UV photons and the formation of first structures in the
universe.


title:
Heating of the fuel mixture due to viscous stress ahead of accelerating
  flames in deflagration-to-detonation transition

abstract:
  The role of viscous stress in heating of the fuel mixture in
deflagration-to-detonation transition in tubes is studied both analytically and
numerically. The analytical theory is developed in the limit of low Mach
number; it determines temperature distribution ahead of an accelerating flame
with maximum achieved at the walls. The heating effects of viscous stress and
the compression wave become comparable at sufficiently high values of the Mach
number. In the case of relatively large Mach number, viscous heating is
investigated by direct numerical simulations. The simulations were performed on
the basis of compressible Navier-Stokes gas-dynamic equations taking into
account chemical kinetics. In agreement with the theory, viscous stress makes
heating and explosion of the fuel mixture preferential at the walls. The
explosion develops in an essentially multi-dimensional way, with fast
spontaneous reaction spreading along the walls and pushing inclined shocks.
Eventually, the combination of explosive reaction and shocks evolves into
detonation.


title:
Multiple stellar populations in three rich Large Magellanic Cloud star
  clusters

abstract:
  We present deep colour-magnitude diagrams for three rich intermediate-age
star clusters in the Large Magellanic Cloud, constructed from archival ACS
F435W and F814W imaging. All three clusters exhibit clear evidence for peculiar
main-sequence turn-offs. NGC 1846 and 1806 each possess two distinct turn-off
branches, while the turn-off for NGC 1783 shows a much larger spread in colour
than can be explained by the photometric uncertainties. We demonstrate that
although all three clusters contain significant populations of unresolved
binary stars, these cannot be the underlying cause of the observed turn-off
morphologies. The simplest explanation is that each cluster is composed of at
least two different stellar populations with very similar metal abundances but
ages separated by up to ~300 Myr. The origin of these unusual properties
remains unidentified; however, the fact that at least three massive clusters
containing multiple stellar populations are now known in the LMC suggests a
potentially significant formation channel.


title: Coupled-channels study of the $\pi^{-}p \to \eta n$ process

abstract:
  The reaction $\pi^{-}p \to \eta n$ is investigated within a dynamical
coupled-channels model of meson production reactions in the nucleon resonance
region. The meson baryon channels included are $\pi N$, $\eta N$, $\pi \Delta$,
$\sigma N$, and $\rho N$. The non-resonant meson-baryon interactions of the
model are derived from a set of Lagrangians by using a unitary transformation
method. One or two excited nucleon states in each of $S$, $P$, $D$, and $F$
partial waves are included to generate the resonant amplitudes. Data of
$\pi^{-}p \to \eta n$ reaction from threshold up to a total center-of-mass
energy of about 2 GeV are satisfactorily reproduced and the roles played by the
following nine nucleon resonances are investigated: $S_{11}(1535)$,
$S_{11}(1650)$, $P_{11}(1440)$, $P_{11}(1710)$, $P_{13}(1720)$, $D_{13}(1520)$,
$D_{13}(1700)$, $D_{15}(1675)$, and $F_{15}(1680)$. The reaction mechanism as
well as the predicted $\eta N$ scattering length are discussed.


title:
Maximum entropy approach to central limit distributions of correlated
  variables

abstract:
  Hilhorst and Schehr recently presented a straight forward computation of
limit distributions of sufficiently correlated random numbers \cite{hilhorst}.
Here we present the analytical form of entropy which --under the maximum
entropy principle (with ordinary constraints)-- provides these limit
distributions. These distributions are not $q$-Gaussians and can not be
obtained with Tsallis entropy.


title:
U_A(1) anomaly and eta' mass from an infrared singular quark-gluon
  vertex

abstract:
  The $U_A(1)$ problem of QCD is inevitably tied to the infrared behaviour of
quarks and gluons with its most visible effect being the $\eta^\prime$ mass. A
dimensional argument of Kogut and Susskind showed that the mixing of the
pseudoscalar flavour-singlet mesons with gluons can provide a screening of the
Goldstone pole in this channel if the full quark-quark interaction is strongly
infrared singular as $\sim 1/k^4$. We investigate this idea using previously
obtained results for the Landau gauge ghost and gluon propagator, together with
recent determinations for the singular behaviour of the quark-gluon vertex. We
find that, even with an infrared vanishing gluon propagator, the singular
structure of the quark-gluon vertex for certain kinematics is apposite for
yielding a non-zero screening mass.


title: New formula for a resonant scattering near an inelastic threshold

abstract:
  We show that the Flatte formula is not adequate to interpret precision data
on a resonance production near an inelastic threshold. A unitary
parameterization, satisfying generalized Watson's theorem for the production
amplitudes, is proposed to replace the Flatte parameterization in
phenomenological analyses of experimental data.


title: Intensity oscillations in coronal XBPs from Hinode/XRT observations

abstract:
  Our aim is to investigate the intensity oscillations in coronal X-ray Bright
Points (XBPs). We analysed a 7-hours long time sequence of the soft X-ray
images obtained on April 14, 2007 with 2-min cadence using X-Ray Telescope
(XRT) on-board the Hinode mission. We use SSW in IDL to derive the time series
of 14 XBPs and 2 background regions. For the first time, we have tried to use
power spectrum analysis on XBPs data to determine the periods of intensity
oscillations. coronal X-ray Bright Points (XBPs). The power spectra of XBPs
show several significant peaks at different frequencies corresponding to a wide
variety of time scales which range from a few minutes to hours. The light
curves of all the XBPs give the impression that the XBPs can be grouped into
three classes depending on emission levels: (i) weak XBPs; (ii) bright XBPs;
and (iii) very strong XBPs. The periods of intensity oscillation are consistent
in all the XBPs and are independent of their brightness level, suggesting that
the heating mechanisms in all the three groups of XBPs are similar. The
different classes of XBPs may be related to the different strengths of the
magnetic field with which they have been associated.


title:
Pairings of Sheaves of $\mathcal{A}$-Modules through Bilinear
  $\mathcal{A}$-Morphisms

abstract:
  It is proved that for any free $\mathcal{A}$-modules $\mathcal{F}$ and
$\mathcal{E}$ of finite rank on some $\mathbb{C}$-algebraized space $(X,
\mathcal{A})$ a \textit{degenerate} bilinear $\mathcal{A}$-morphism $\Phi:
\mathcal{F}\times \mathcal{E}\longrightarrow \mathcal{A}$ induces a
\textit{non-degenerate} bilinear $\mathcal{A}$-morphism $\bar{\Phi}:
\mathcal{F}/\mathcal{E}^\perp\times
\mathcal{E}/\mathcal{F}^\perp\longrightarrow \mathcal{A}$, where
$\mathcal{E}^\perp$ and $\mathcal{F}^\perp$ are the \textit{orthogonal}
sub-$\mathcal{A}$-modules associated with $\mathcal{E}$ and $\mathcal{F}$,
respectively. This result generalizes the finite case of the classical result,
which states that given two vector spaces $W$ and $V$, paired into a field $k$,
the induced vector spaces $W/V^\perp$ and $V/W^\perp$ have the same dimension.
Some related results are discussed as well.


title:
Low Temperature Transport and Specific Heat Studies of
  Nd_{1-x}Pb_{x}MnO_{3} Single Crystals

abstract:
  Electrical transport and specific heat properties of Nd_{1-x}Pb_{x}MnO_{3}
single crystals for 0.15 < x 0.5 have been studied in low temperature regime.
The resistivity in the ferromagnetic insulating (FMI) phase for x < 0.3 has an
activated character. The dependence of the activation gap Delta on doping x has
been determined and the critical concentration for the zero-temperature
metal-insulator transition was determined as x_{c} ~ 0.33. For a metallic
sample with x=0.42, a conventional electron-electron (e-e) scattering term
proportional T^{2} is found in the low-temperature electrical resistivity,
although the Kadowaki-Woods ratio is found to be much larger for this manganite
than for a normal metal. For a metallic sample with x=0.5, a resistivity
minimum is observed for x= 0.5. The effect is attributed to weak localization
and can be described by a negative T^{1/2} weak-localization contribution to
resistivity for a disordered three-dimensional electron system. The specific
heat data have been fitted to contributions from free electrons (gamma), spin
excitations (beta_{3/2}), lattice and a Schottky-like anomaly related to the
rare-earth magnetism of the Nd ions. The value of gamma is larger than for
normal metals, which is ascribed to magnetic ordering effects involving Nd.
Also, the Schottky-like anomaly appears broadened and weakened suggesting
inhomogeneous molecular fields at the Nd-sites.


title: Multiwavelength studies of the gas and dust disc of IRAS 04158+2805

abstract:
  We present a study of the circumstellar environment of IRAS 04158+2805 based
on multi-wavelength observations and models. Images in the optical and
near-infrared, a polarisation map in the optical, and mid-infrared spectra were
obtained with VLT-FORS1, CFHT-IR, and Spitzer-IRS. Additionally we used an
X-ray spectrum observed with Chandra. We interpret the observations in terms of
a central star surrounded by an axisymmetric circumstellar disc, but without an
envelope, to test the validity of this simple geometry. We estimate the
structural properties of the disc and its gas and dust content. We modelled the
dust disc with a 3D continuum radiative transfer code, MCFOST, based on a
Monte-Carlo method that provides synthetic scattered light images and
polarisation maps, as well as spectral energy distributions. We find that the
disc images and spectral energy distribution narrowly constrain many of the
disc model parameters, such as a total dust mass of 1.0-1.75x10^-4 sollar
masses and an inclination of 62-63 degrees. The maximum grain size required to
fit all available data is of the order of 1.6-2.8 microns although the upper
end of this range is loosely constrained. The observed optical polarisation map
is reproduced well by the same disc model, suggesting that the geometry we find
is adequate and the optical properties are representative of the visible dust
content. We compare the inferred dust column density to the gas column density
derived from the X-ray spectrum and find a gas-to-dust ratio along the line of
sight that is consistent with the ISM value. To our knowledge, this measurement
is the first to directly compare dust and gas column densities in a
protoplanetary disc.


title: Semi-bounded unitary representations of infinite-dimensional Lie groups

abstract:
  In this note we introduce the concept of a semi-bounded unitary
representations of an infinite-dimensional Lie group $G$. Semi-boundedness is
defined in terms of the corresponding momentum set in the dual $\g'$ of the Lie
algebra $\g$ of $G$. After dealing with some functional analytic issues
concerning certain weak-$*$-locally compact subsets of dual spaces, called
semi-equicontinuous, we characterize unitary representations which are bounded
in the sense that their momentum set is equicontinuous, we characterize
semi-bounded representations of locally convex spaces in terms of spectral
measures, and we also describe a method to compute momentum sets of unitary
representations of reproducing kernel Hilbert spaces of holomorphic functions.


title:
Limited resources and evolutionary learning may help to understand the
  mistimed reproduction in birds caused by climate change

abstract:
  We present an agent-based model inspired by the Evolutionary Minority Game
(EMG), albeit strongly adapted to the case of competition for limited resources
in ecology. The agents in this game become able, after some time, to predict
the a priori best option as a result of an evolution-driven learning process.
We show that a self-segregated social structure can emerge from this process,
i.e., extreme learning strategies are always favoured while intermediate
learning strategies tend to die out. This result may contribute to
understanding some levels of organization and cooperative behaviour in
ecological and social systems. We use the ideas and results reported here to
discuss an issue of current interest in ecology: the mistimings in egg laying
observed for some species of bird as a consequence of their slower rate of
adaptation to climate change in comparison with that shown by their prey. Our
model supports the hypothesis that habitat-specific constraints could explain
why different populations are adapting differently to this situation, in
agreement with recent experiments.


title: Stability and Throughput of Buffered Aloha with Backoff

abstract:
  This paper studies the buffered Aloha with K-exponential backoff collision
resolution algorithms. The buffered Aloha network is modeled as a multi-queue
single-server system. We adopt a widely used approach in packet switching
systems to decompose the multi-queue system into independent first-in-first-out
(FIFO) queues, which are hinged together by the probability of success of
head-of-line (HOL) packets. A unified method is devised to tackle the stability
and throughput problems of K-exponential backoff with any cutoff phase K. For
networks with a finite number of nodes, we show that the K-exponential backoff
is stable if the retransmission factor is properly chosen from the stable
region. The maximum stable throughput is derived and demonstrated via examples
of geometric retransmission (K=1) and exponential backoff (K=infinity). For
networks with an infinite number of nodes, we show that geometric
retransmission is unstable, and the stable network throughput of exponential
backoff can only be achieved at the cost of potential unbounded delay in each
input queue. Furthermore, we address the stability issue of the systems at the
undesired stable point. All analytical results presented in this paper are
verified and confirmed by simulations.


title: Comment on the Quantum Brachistochrone Problem

abstract:
  In this brief comment we attempt to clarify the apparent discrepancy between
the papers [1] and [2] on the quantum brachistochrone, namely whether it is
possible to use a judicious mixture of Hermitian and non-Hermitian quantum
mechanics to evade the standard lower limit on the time taken for evolution by
a Hermitian Hamiltonian with given energy dispersion between two given states.


title: Bethe-Sommerfeld conjecture for pseudodifferential perturbation

abstract:
  We consider a periodic pseudodifferential operator $H=(-\Delta)^l+A$ ($l>0$)
in $\R^d$ which satisfies the following conditions: (i) the symbol of $H$ is
smooth in $x$, and (ii) the perturbation $A$ has order smaller than $2l-1$.
Under these assumptions, we prove that the spectrum of $H$ contains a
half-line.


title:
Mathematical Modeling of Soliton's Evolution in Generalized Quantum
  Hydrodynamics

abstract:
  This paper addresses the fundamental principles of generalized Boltzmann
physical kinetics, as a part of non-local physics. It is shown that the theory
of transport processes (including quantum mechanics) can be considered in the
frame of unified theory based on the non-local physical description. The paper
can be considered also as comments and prolongation of the materials published
in the known author's monograph (Boris V. Alexeev, Generalized Boltzmann
Physical Kinetics. Elsevier. 2004). The theory leads to solitons as typical
formations in the generalized quantum hydrodynamics.


title: An Approach towards a Constituent Quark Model on the Light Cone

abstract:
  We use the vacuum expectation value of a Wegner-Wilson loop representing a
fast moving quark-antiquark pair to derive the light cone Hamiltonian for a
$q\bar q$ meson. We solve the corresponding Schr\"odinger equation for various
trial wave functions. The result shows how confinement determines the meson
mass and wave function for valence quarks on the light cone. We also
parametrize the effect of the spin-dependent splitting for a light meson and
charmonium. The correct chiral-symmetry breaking pattern for the pion mass is
obtained due to the self-energy of the quark.


title: Power law cosmology - a viable alternative

abstract:
  A power law cosmology is defined by the cosmological scale factor evolving as
$t^{\alpha}$. In this work, we put bounds on $\alpha$ by using the joint test
of the SNe Ia data from Supernova Legacy Survey (SNLS) and H(z) data with
curvature constant $ k = 0, \pm 1$. We observe that the combined analysis with
SNLS and H(z) data favours the open power cosmology with $\alpha =
1.31^{+0.06}_{-0.05}. It is also interesting to note that an Einstein - de
Sitter model $(\alpha = 2/3)$ is ruled out at $2\sigma$ level.


title:
Hawking radiation and near horizon universality of chiral Virasoro
  algebra

abstract:
  We show that the diffeomorphism anomaly together with the trace anomaly
reveal a chiral Virasoro algebra near the event horizon of a black hole. This
algebra is the same irrespective of whether the anomaly is covariant or
consistent, thereby manifesting its universal character and the fact that only
the outgoing modes are relevant near the horizon. Our analysis therefore
clarifies the role of the trace anomaly in the diffeomorphism anomaly approach
\cite{wilczek, isowilczek, shailesh, shailesh2, sunandan, sunandan10, rabin10}
to the Hawking radiation.


title: Affine quotients of supergroups

abstract:
  In this article we consider sheaf quotients of affine superschemes by affine
supergroups that act on them freely. The necessary and sufficient conditions
for such quotients to be affine are given. If $G$ is an affine supergroup and
$H$ is its normal supersubgroup, then we prove that a dur $K$-sheaf
$\tilde{\tilde{G/H}}$ is again affine supergroup. Additionally, if $G$ is
algebraic, then a $K$-sheaf $\tilde{G/H}$ is also algebraic supergroup and it
coincides with $\tilde{\tilde{G/H}}$. In particular, any normal supersubgroup
of an affine supergroup is faithfully exact.


title: Large p-groups actions with |G| /g^2 > 4/ (p^2-1)^2

abstract:
  Let k be an algebraically closed field of characteristic p>0 and C a
connected nonsingular projective curve over k with genus g>1. Let (C,G) be a
"big action", i.e. a pair (C,G) where G is a p-subgroup of the k-automorphism
group of C such that |G|/g > 2p / p-1. We first study finiteness results on the
values taken by the quotient |G|/g^2 when (C,G) runs over the big actions
satisfying |G|/g^2 >M, for a given positive real M>0. Then, we exhibit a
classification and a parametrization of such big actions when M=4/ (p^2-1)^2.


title: On the Kernel of the affine Dirac operator

abstract:
  Let L be a finite-dimensional semisimple Lie algebra with a non-degenerate
invariant bilinear form, \sigma an elliptic automorphism of L leaving the form
invariant, and A a \sigma-invariant reductive subalgebra of L, such that the
restriction of the form to A is non-degenerate. Consider the associated twisted
affine Lie algebras L^, A^, and let F be the \sigma-twisted Clifford module
over A^ associated to the orthocomplement of A in L. Under suitable hypotheses
on\sigma and A, we provide a general formula for the decomposition of the
kernel of the affine Dirac operator, acting on the tensor product of an
integrable highest weight L^-module and F, into irreducible A^-submodules.
  As an application, we derive the decomposition of all level 1 integrable
irreducible highest weight modules over orthogonal affine Lie algebras with
respect to the affinization of the isotropy subalgebra of an arbitrary
symmetric space.


title:
Arr\^et optimal pour les processus de Markov forts et les fonctions
  affines

abstract:
  In this Note we study optimal stopping problems for strong Markov processes
and affine functions. We give a justification of the Snell envelope form using
standard results of optimal stopping. We also justify the convexity of the
value function, and without a priori restriction to a particular class of
stopping times, we deduce that the smallest optimal stopping time is
necessarily a hitting time.


title: Random Walk in deterministically changing environment

abstract:
  We consider a random walk with transition probabilities weakly dependent on
an environment with a deterministic, but strongly chaotic, evolution. We prove
that for almost all initial conditions of the environment the walk satisfies
the CLT.


title: The double scaling limit method in the Toda hierarchy

abstract:
  Critical points of semiclassical expansions of solutions to the dispersionful
Toda hierarchy are considered and a double scaling limit method of
regularization is formulated. The analogues of the critical points
characterized by the strong conditions in the Hermitian matrix model are
analyzed and the property of doubling of equations is proved. A wide family of
sets of critical points is introduced and the corresponding double scaling
limit expansions are discussed.


title:
Contribution of dielectrics to frequency and noise of NbTiN
  superconducting resonators

abstract:
  We study NbTiN resonators by measurements of the temperature dependent
resonance frequency and frequency noise. Additionally, resonators are studied
covered with SiOx dielectric layers of various thicknesses. The resonance
frequency develops a non-monotonic temperature dependence with increasing SiOx
layer thickness. The increase in the noise is independent of the SiOx
thickness, demonstrating that the noise is not dominantly related to the low
temperature resonance frequency deviations.


title:
Natural pseudo-distance and optimal matching between reduced size
  functions

abstract:
  This paper studies the properties of a new lower bound for the natural
pseudo-distance. The natural pseudo-distance is a dissimilarity measure between
shapes, where a shape is viewed as a topological space endowed with a
real-valued continuous function. Measuring dissimilarity amounts to minimizing
the change in the functions due to the application of homeomorphisms between
topological spaces, with respect to the $L_\infty$-norm. In order to obtain the
lower bound, a suitable metric between size functions, called matching
distance, is introduced. It compares size functions by solving an optimal
matching problem between countable point sets. The matching distance is shown
to be resistant to perturbations, implying that it is always smaller than the
natural pseudo-distance. We also prove that the lower bound so obtained is
sharp and cannot be improved by any other distance between size functions.


title: Lattice simulations for few- and many-body systems

abstract:
  We review the recent literature on lattice simulations for few- and many-body
systems. We focus on methods and results that combine the framework of
effective field theory with computational lattice methods. Lattice effective
field theory is discussed for cold atoms as well as low-energy nucleons with
and without pions. A number of different lattice formulations and computational
algorithms are considered, and an effort is made to show common themes in
studies of cold atoms and low-energy nuclear physics as well as common themes
in work by different collaborations.


title:
Observational searches for g-mode oscillations in the quiet solar
  atmosphere from TRACE 1600A Continuum Observations

abstract:
  Our aim is to search for atmospheric g-mode oscillations in UV network, UV
bright points and Uv background regions. We have analysed a 6-hours of time
sequence of ultraviolet (uv) images obtained on May 24, 2003 in 1600A continuum
under high spatial and temporal resolution from Transition Region and Coronal
Explorer (TRACE). We have selected an isolated 15 uv bright points, 15 uv
network elements and 15 uv background regions in a quiet region from the images
for the detailed analysis. We derived the cumulative intensity values of these
features. The light curves of all the features have been derived for the total
duration of observations and done the power spectrum analysis using the time
series data. We found that the uv bright points, the uv network and uv
background regions will exhibit a longer period of intensity oscillations
namely, 5.5 hours, 4.6 hours and 3.4 hours respectively, in addition to the
more familiar small scale intensity fluctuations. We suggest that the longer
periods of oscillation may be related to solar atmospheric g-modes.


title: Quantum Zeno Effect in Radical-Ion-Pair Recombination Reactions

abstract:
  Radical-ion pairs are ubiquitous in a wide range of biochemical reactions,
ranging from photosynthesis to magnetic sensitive chemical reactions underlying
avian magnetic navigation. We here show that the charge recombination of a
radical-ion-pair is a continuous quantum measurement process that interrogates
the spin state of the pair. This naturally leads to the appearance of the
quantum Zeno effect, explaining a large amount of data on unusually long-lived
radical-ion-pairs.


title:
Finding the sigma pole by analytic extrapolation of $\pi\pi$ scattering
  data

abstract:
  We investigate the determination of the $\sigma$ pole from $\pi\pi$
scattering data below the $K\bar{K}$ threshold, including the new precise
results obtained from $K_{e4}$ decay by NA48/2 Collaboration. We discuss also
the experimental status of the threshold parameters $a_0^0$ and $b_0^0$ and the
phase shift $\delta_0^0$. In order to reduce the theoretical bias, we use a
large class of analytic parametrizations of the isoscalar $S$-wave, based on
expansions in powers of conformal variables. The $\sigma$ pole obtained with
this method is consistent with the prediction based on ChPT and Roy equations.
However, the theoretical uncertainties are now larger, reflecting the
sensitivity of the pole position to the specific parametrizations valid in the
physical region. We conclude that Roy equations offer the most precise method
for the determination of the $\sigma$ pole from $\pi\pi$ elastic scattering.


title: A geometric study of Wasserstein spaces: Euclidean spaces

abstract:
  We study the Wasserstein space (with quadratic cost) of Euclidean spaces as
an intrinsic metric space. In particular we compute their isometry groups.
Surprisingly, in the case of the line, there exists a (unique) "exotic"
isometric flow. This contrasts with the case of higher-dimensional Euclidean
spaces, where all isometries of the Wasserstein space preserve the shape of
measures. We also study the curvature and various ranks of these spaces.


title: All orders analysis of three dimensional CP^(N-1) model in 1/N-expansion

abstract:
  The renormalizability of the three dimensional supersymmetric CP^(N - 1)
model is discussed in the 1/N-expansion method, to all orders of 1/N. The model
has N copies of the dynamical field and the amplitudes are expanded in powers
of 1/N. In order to see the effects of supersymmetry explicitly, Feynman rules
for superfields are used. All divergences in amplitudes can be eliminated by
the renormalizations of the coupling constant and the wavefunction of the
dynamical field to all orders of 1/N. The beta function of the coupling
constant is also calculated to all orders of 1/N. It is shown that this model
has a non-trivial ultraviolet fixed point. The beta function is shown to have
no higher order correction in the 1/N-expansion.


title: Sixteen New Linear Codes With Plotkin Sum

abstract:
  Sixteen new linear codes are presented: three of them improve the lower
bounds on the minimum distance for a linear code and the rest are an explicit
construction of unknown codes attaining the lower bounds on the minimum
distance. They are constructed using the Plotkin sum of two linear codes, also
called $(u|u+v)$ construction. The computations have been achieved using an
exhaustiv search.


title:
Solar coronal differential rotation from XBPs in Hinode/XRT and
  Yohkoh/SXT images

abstract:
  Our aim is to identify and trace the X-ray Bright Points (XBPs) over the disk
and use them as tracers to determine the coronal rotation. This investigation
will help to clarify and understand several issues: whether (i) the corona
rotates differentially; (ii) the rotation depends on the sizes of the XBPs; and
(iii) dependence on phases of the solar magnetic cycle. We analysed the daily
full-disk soft X-ray images observed with (i) X-Ray Telescope (XRT) on-board
the Hinode mission during January, March and April, 2007 and (ii) Soft X-ray
Telescope (SXT) on-board the Yohkoh from 1992 to 2001 using SSW in IDL. We have
used the tracer method to trace the passage of XBPs over the solar disk with
the help of overlaying grids and derived the sidereal angular rotation velocity
and the coordinates (latitude and longitude) of the XBPs. We have determined
the position of a large number of XBPs both in Hinode/XRT and Yohkoh/SXT images
and followed them over the solar disk as a function of time. We derived the
coronal sidereal angular rotation velocity and compared it with heliocentric
latitude and as a function of solar activity cycle. In addition, we measured
the sizes of all the XBPs and related them with the coronal rotation. The
important results derived from these investigations are: (i) the solar corona
rotates differentially like the photosphere and chromosphere; (ii) the sidereal
angular rotation velocity is independent of the sizes of the XBPs; (iii) the
sidereal angular rotation velocity does not depend on phases of the solar
magnetic cycle; and (iv) the differential rotation of the corona is present
throughout the solar magnetic cycle.


title:
Electroproduction of Eta Mesons in the S11(1535) Resonance Region at
  High Momentum Transfer

abstract:
  The differential cross-section for the process p(e,e'p)eta has been measured
at Q2 ~ 5.7 and 7.0 (GeV/c)2 for centre-of-mass energies from threshold to 1.8
GeV, encompassing the S11(1535) resonance, which dominates the channel. This is
the highest momentum transfer measurement of this exclusive process to date.
The helicity-conserving transition amplitude A_1/2, for the production of the
S11(1535) resonance, is extracted from the data. Within the limited Q2 now
measured, this quantity appears to begin scaling as 1/Q3 - a predicted, but not
definitive, signal of the dominance of perturbative QCD, at Q2 ~ 5 (GeV/c)2.


title: Scaling relation for earthquake networks

abstract:
  The scaling relation derived by Dorogovtsev, Goltsev, Mendes and Samukhin
[Phys. Rev. E, 68 (2003) 046109] states that the exponents of the power-law
connectivity distribution, gamma, and the power-law eigenvalue distribution of
the adjacency matrix, delta, of a locally treelike scale-free network satisfy
2*gamma - delta = 1 in the mean field approximation. Here, it is shown that
this relation holds well for the reduced simple earthquake networks (without
tadpole-loops and multiple edges) constructed from the seismic data taken from
California and Japan. The result is interpreted from the viewpoint of the
hierarchical organization of the earthquake networks.


title: Hardy type inequality in variable Lebesgue spaces

abstract:
  We prove that in variable exponent spaces $L^{p(\cdot)}(\Omega)$, where
$p(\cdot)$ satisfies the log-condition and $\Omega$ is a bounded domain in
$\mathbf R^n$ with the property that $\mathbf R^n \backslash \bar{\Omega}$ has
the cone property, the validity of the Hardy type inequality $$|
1/\delta(x)^\alpha \int_\Omega \phi(y) dy/|x-y|^{n-\alpha}|_{p(\cdot)} \leqq C
|\phi|_{p(\cdot)}, \quad 0<\al<\min(1,\frac{n}{p_+})$$, where
$\delta(x)=\mathrm{dist}(x,\partial\Omega)$, is equivalent to a certain
property of the domain $\Om$ expressed in terms of $\al$ and $\chi_\Om$.