title:
Triggered or Self-Regulated Star Formation within Intermediate Redshift
  Luminous Infrared Galaxies (I). Morphologies and Spatially Resolved Spectral
  Energy Distributions

abstract:
  We imaged a set of 15 intermediate redshift (z~0.8) luminous infrared
galaxies (LIRGs) with the Keck Laser Guide Star (LGS) AO facility. These
galaxies were selected from the GOODS-S field, allowing us to combine the high
spatial resolution HST optical (B, V, i, and z-bands) images with our
near-infrared (K'-band) images to study the LIRG morphologies and spatially
resolved spectral energy distributions (SEDs). Two thirds of the LIRGs are disk
galaxies, with only one third showing some evidence for interactions, minor, or
major mergers. In contrast with local LIRG disks (which are primarily barred
systems), only 10% of the LIRG disks in our sample contain a prominent bar.
While the optical bands tend to show significant point-like substructure,
indicating distributed star formation, the AO K-band images tend to be smooth.
The SEDs of the LIRGs are consistent with distributed dusty star formation, as
exhibited by optical to IR colors redder than allowed by old stellar
populations alone. This effect is most pronounced in the galaxy cores, possibly
indicating central star formation. We also observed a set of 11 intermediate
redshift comparison galaxies, selected to be non-ellipticals with apparent
K-band magnitudes comparable to the LIRGs. The "normal" (non-LIRG) systems
tended to have lower optical luminosity, lower stellar mass, and more irregular
morphology than the LIRGs. Half of the "normal" galaxies have SEDs consistent
with intermediate aged stellar populations and minimal dust. The other half
show evidence for some dusty star formation, usually concentrated in their
cores. Our work suggests that the LIRG disk galaxies are similar to large disk
systems today, undergoing self regulated star formation, only at 10 - 20 times
higher rates. (Abridged)


title:
A Constrained Channel Coding Approach to Joint Communication and Channel
  Estimation

abstract:
  A joint communication and channel state estimation problem is investigated,
in which reliable information transmission over a noisy channel, and
high-fidelity estimation of the channel state, are simultaneously sought. The
tradeoff between the achievable information rate and the estimation distortion
is quantified by formulating the problem as a constrained channel coding
problem, and the resulting capacity-distortion function characterizes the
fundamental limit of the joint communication and channel estimation problem.
The analytical results are illustrated through case studies, and further issues
such as multiple cost constraints, channel uncertainty, and capacity per unit
distortion are also briefly discussed.


title:
Origin of the Structural and Magnetic Anomaly of the Layered Compound
  SrFeO2: A Density Functional Investigation

abstract:
  The structural and magnetic anomaly of the layered compound SrFeO$_{2}$ were
examined by first principles density functional calculations and Monte Carlo
simulations. The down-spin Fe 3$d$ electron occupies the $d_{z^2}$ level rather
than the degenerate ($d_{xz}$, $d_{yz}$) levels, which explains the absence of
Jahn-Teller instability, the easy ab-plane magnetic anisotropy and the observed
three-dimensional (0.5, 0.5, 0.5) antiferromagnetic order. Monte Carlo
simulations show that the strong inter-layer spin exchange is essential for the
high N\'eel temperature.


title:
An Addendum to "How Good is PSK for Peak-Limited Fading Channels in the
  Low-SNR Regime?"

abstract:
  A proof is provided of the operational achievability of $R_\mathrm{rt}$ by
the recursive training scheme in \cite{zhang07:it}, for general wide-sense
stationary and ergodic Rayleigh fading processes.


title:
Decoding sequential vs non-sequential two-photon double ionization of
  helium using nuclear recoil

abstract:
  Above 54.4 eV, two-photon double ionization of helium is dominated by a
sequential absorption process, producing characteristic behavior in the single
and triple differential cross sections. We show that the signature of this
process is visible in the nuclear recoil cross section, integrated over all
energy sharings of the ejected electrons, even below the threshold for the
sequential process. Since nuclear recoil momentum imaging does not require
coincident photoelectron measurement, the predicted images present a viable
target for future experiments with new short-pulse VUV and soft X-ray sources.


title: Comments on Unparticles

abstract:
  We comment on several points concerning unparticles which have been
overlooked in the literature. One regards Mack's unitarity constraint lower
bounds on CFT operator dimensions,e.g. d\geq 3 for primary, gauge invariant,
vector unparticle operators. We correct the results in the literature to
account for this, and also for a needed correction in the form of the
propagator for vector and tensor unparticles. We show that the unitarity
constraints can be directly related to unitarity requirements on scattering
amplitudes of particles, e.g. those of the standard model, coupled to the CFT
operators. We also stress the existence of explicit standard model contact
terms, which are generically induced by the coupling to the CFT (or any other
hidden sector), and are subject to LEP bounds. Barring an unknown mechanism to
tune away these contact interactions, they can swamp interference effects
generated by the CFT. We illustrate these points in the context of a weakly
coupled CFT example. A significant amount of the unparticle literature should
be reconsidered in light of the observations in this note.


title:
Coding Strategies for Noise-Free Relay Cascades with Half-Duplex
  Constraint

abstract:
  Two types of noise-free relay cascades are investigated. Networks where a
source communicates with a distant receiver via a cascade of half-duplex
constrained relays, and networks where not only the source but also a single
relay node intends to transmit information to the same destination. We
introduce two relay channel models, capturing the half-duplex constraint, and
within the framework of these models capacity is determined for the first
network type. It turns out that capacity is significantly higher than the rates
which are achievable with a straightforward time-sharing approach. A capacity
achieving coding strategy is presented based on allocating the transmit and
receive time slots of a node in dependence of the node's previously received
data. For the networks of the second type, an upper bound to the rate region is
derived from the cut-set bound. Further, achievability of the cut-set bound in
the single relay case is shown given that the source rate exceeds a certain
minimum value.


title:
A Precise Proper Motion for the Crab Pulsar, and the Difficulty of
  Testing Spin-Kick Alignment for Young Neutron Stars

abstract:
  We present a detailed measurement of the proper motion of the Crab pulsar,
with the primary goal of comparing the direction of its proper motion with the
projected axis of its pulsar wind nebula (the projected spin axis of the
pulsar). We demonstrate that our measurement is robust and has an uncertainty
of only +/-0.4 mas/yr on each component of the proper motion. We find mu_alpha
= -11.7+/-0.4+/-0.5 mas/yr and mu_delta = +4.2+/-0.4+/-0.5 mas/yr relative to
the pulsar's standard of rest, where the two uncertainties are from the
measurement and the ncertainties in correcting the proper motion reference
frame, respectively. Comparing this proper motion to the symmetry axis of the
pulsar wind nebula, we must also consider the unknown velocity of the pulsar's
progenitor (assumed to be ~10 km/s), and hence add an additional uncertainty of
+/-2 mas/yr to each component of the proper motion, although this could be
significantly larger. This implies a projected misalignment with the nebular
axis of 14+/-2+/-9 degrees. We conclude that the precision of individual
measurements which compare the direction of motion of a neutron star to a fixed
axis will often be limited by fundamental uncertainties regarding reference
frames and progenitor properties. The question of spin-kick (mis)alignment, and
its implications for asymmetries and other processes during supernova
core-collapse, is best approached by considering a statistical ensemble of such
measurements, rather than detailed studies of individual sources. [abriged]


title: Nearby, Thermally Emitting Neutron Stars

abstract:
  We describe a sample of thermally emitting neutron stars discovered in the
ROSAT All-Sky Survey. We discuss the basic observational properties of these
objects and conclude that they are nearby, middle-aged pulsars with moderate
magnetic fields that we see through their cooling radiation. While these
objects are potentially very useful as probes of matter at very high densities
and magnetic fields, our lack of understanding of their surface emission limits
their current utility. We discuss this and other outstanding problems: the
spectral evolution of one sources and the relation of this population to the
overall pulsar population.


title:
Alloy surface segregation in reactive environments: A first-principles
  atomistic thermodynamics study of Ag3Pd(111) in oxygen atmospheres

abstract:
  We present a first-principles atomistic thermodynamics framework to describe
the structure, composition and segregation profile of an alloy surface in
contact with a (reactive) environment. The method is illustrated with the
application to a Ag3Pd(111) surface in an oxygen atmosphere, and we analyze
trends in segregation, adsorption and surface free energies. We observe a wide
range of oxygen adsorption energies on the various alloy surface
configurations, including binding that is stronger than on a Pd(111) surface
and weaker than that on a Ag(111) surface. This and the consideration of even
small amounts of non-stoichiometries in the ordered bulk alloy are found to be
crucial to accurately model the Pd surface segregation occurring in
increasingly O-rich gas phases.


title:
Spin-orbital coupling effect on Josephson current through a
  superconductor heterojunction

abstract:
  We study spin-orbital coupling effect on the Josephson current through a
superconductor (SC) heterojunction, consisting of two s-wave superconductors
and a two-dimensional electron gas (2DEG) layer between them. The Rashba-type
(RSOC) and/or Dresselhaus-type (DSOC) of spin-orbital coupling are considered
in the 2DEG region. By using the lattice Bogoliubov-de Gennes equation and the
Keldysh formalism, we calculate the DC supercurrent flowing through the
junction and find that the critical current $I_c$ exhibits a damped oscillation
with both the strength of SOC and the layer length of 2DEG; especially, the
strength ratio between RSOC and DSOC can also induce switching between the $0$
state and the $\pi$ state of the SC/2DEG/SC junction as well. This $0$-$\pi$
transition results from the fact that SOC in a two-dimension system can lead to
a pseudo-magnetic effect on the flowing electrons like the effect of a
ferromagnet, since the time reversal symmetry of the system has already been
broken by two SC leads with different macroscopic phases.


title:
Yang's Model as Triply Special Relativity and the Snyder's Model--de
  Sitter Special Relativity Duality

abstract:
  We show that if Yang's model as the earliest TSR is completed, it should
contain both Snyder's quantized space-time model as the earliest DSR, the de
Sitter SR and their duality.


title:
Particle Acceleration and Non-Thermal Emission in Pulsar Outer
  Magnetospheric Gap

abstract:
  A two-dimensional electrodynamic model is used to study particle acceleration
and non-thermal emission mechanisms in the pulsar magnetospheres.
  We solve distribution of the accelerating electric field with the emission
process and the pair-creation process in meridional plane, which includes the
rotational axis and the magnetic axis. By solving the evolutions of the Lorentz
factor, and of the pitch angle, we calculate spectrum in optical through
$\gamma$-ray bands with the curvature radiation, synchrotron radiation, and
inverse-Compton process not only for outgoing particles, but also for ingoing
particles, which were ignored in previous studies. We apply the theory to the
Vela pulsar. We find that the curvature radiation from the outgoing particles
is the major emission process above 10 MeV bands. In soft $\gamma$-ray to hard
X-ray bands, the synchrotron radiation from the ingoing primary particles in
the gap dominates in the spectrum. Below hard X-ray bands, the synchrotron
emissions from both outgoing and ingoing particles contribute to the calculated
spectrum. The calculated spectrum is consistent with the observed
phase-averaged spectrum of the Vela pulsar. We show that the observed five-peak
pulse profile in the X-ray bands of the Vela pulsar is reproduced by the inward
and outward emissions, and the observed double-peak pulse profile in
$\gamma$-ray bands is explained by the outward emissions.


title: Operator Coupling of Gauge Fields and Unparticles

abstract:
  We show that it is possible to couple gauge fields to unparticles without the
use of path integrals in the unparticle effective action. This is done by
treating the unparticle field as a vector in an abstract Hilbert space and the
gauge field as an operator on that space.


title:
Trace initial interaction from final state observable in relativistic
  heavy ion collisions

abstract:
  In order to trace the initial interaction in ultra-relativistic heavy ion
collision in all azimuthal directions, two azimuthal multiplicity-correlation
patterns -- neighboring and fixed-to-arbitrary angular-bin correlation patterns
-- are suggested. From the simulation of Au + Au collisions at 200 GeV by using
the Monte Carlo models RQMD with hadron re-scattering and AMPT with and without
string melting, we observe that the correlation patterns change gradually from
out-of-plane preferential one to in-plane preferential one when the centrality
of collision shifts from central to peripheral, meanwhile the anisotropic
collective flow v_2 keeps positive in all cases. This regularity is found to be
model and collision energy independent. The physics behind the two opposite
trends of correlation patterns, in particular, the presence of out-of-plane
correlation patterns at RHIC energy, are discussed.


title:
Observation of Three Mode Parametric Interactions in Long Optical
  Cavities

abstract:
  We report the first observation of three-mode opto-acoustic parametric
interactions of the type predicted to cause parametric instabilities in an 80 m
long, high optical power cavity that uses suspended sapphire mirrors. Resonant
interaction occurs between two distinct optical modes and an acoustic mode of
one mirror when the difference in frequency between the two optical cavity
modes is close to the frequency of the acoustic mode. Experimental results
validate the theory of parametric instability in high power optical cavities.


title:
Studying Turbulence from Doppler-broadened Absorption Lines: Statistics
  of Logarithms of Intensity

abstract:
  We continue our work on developing techniques for studying turbulence with
spectroscopic data. We show that Doppler-broadened absorption spectral lines,
in particularly, saturated absorption lines, can be used within the framework
of the earlier-introduced technique termed the Velocity Coordinate spectrum
(VCS). The VCS relates the statistics of fluctuations along the velocity
coordinate to the statistics of turbulence, thus it does not require spatial
coverage by sampling directions in the plane of the sky. We consider lines with
different degree of absorption and show that for lines of optical depth less
than one, our earlier treatment of the VCS developed for spectral emission
lines is applicable, if the optical depth is used instead of intensity. This
amounts to correlating the logarithms of absorbed intensities. For larger
optical depths and saturated absorption lines, we show, that the amount of
information that one can use is, inevitably, limited by noise. In practical
terms, this means that only wings of the line are available for the analysis.
In terms of the VCS formalism, this results in introducing an additional
window, which size decreases with the increase of the optical depth. As a
result, strongly saturated absorption lines carry the information only about
the small scale turbulence. Nevertheless, the contrast of the fluctuations
corresponding to the small scale turbulence increases with the increase of the
optical depth, which provides advantages for studying turbulence combining
lines with different optical depths. Combining different absorption lines one
can tomography turbulence in the interstellar gas in all its complexity.


title:
Prospects for $\phi$ meson production in pp collisions at the ALICE
  experiment

abstract:
  The ALICE experiment at the CERN Large Hadron Collider (LHC) will allow the
study of resonance production in nucleus-nucleus and proton-proton collisions.
This paper presents results based on physics performance studies to discuss
prospects in ALICE for $\phi$(1020) meson production in pp interactions during
the LHC startup.


title: What's new with the XYZ mesons?

abstract: I review some of the recent experimental results on the so-called XYZ mesons.


title: Teleportation fidelity as a probe of sub-Planck phase-space structure

abstract:
  We investigate the connection between sub-Planck structure in the Wigner
function and the output fidelity of continuous-variable teleportation
protocols. When the teleporting parties share a two-mode squeezed state as an
entangled resource, high fidelity in the output state requires a squeezing
large enough that the smallest sub-Planck structures in an input pure state are
teleported faithfully. We formulate this relationship, which leads to an
explicit relation between the fine-scale structure in the Wigner function and
large-scale extent of the Wigner function, and we treat specific examples,
including coherent, number, and random states and states produced by chaotic
dynamics. We generalize the pure-state results to teleportation of mixed
states.


title:
Nature of magnetic coupling between Mn ions in as-grown
  Ga$_{1-x}$Mn$_{x}$As studied by x-ray magnetic circular dichroism

abstract:
  The magnetic properties of as-grown Ga$_{1-x}$Mn$_{x}$As have been
investigated by the systematic measurements of temperature and magnetic field
dependent soft x-ray magnetic circular dichroism (XMCD). The {\it intrinsic}
XMCD intensity at high temperatures obeys the Curie-Weiss law, but residual
spin magnetic moment appears already around 100 K, significantly above Curie
temperature ($T_C$), suggesting that short-range ferromagnetic correlations are
developed above $T_C$. The present results also suggest that antiferromagnetic
interaction between the substitutional and interstitial Mn (Mn$_{int}$) ions
exists and that the amount of the Mn$_{int}$ affects $T_C$.


title:
The dark matter environment of the Abell 901/902 supercluster: a weak
  lensing analysis of the HST STAGES survey

abstract:
  We present a high resolution dark matter reconstruction of the z=0.165 Abell
901/902 supercluster from a weak lensing analysis of the HST STAGES survey. We
detect the four main structures of the supercluster at high significance,
resolving substructure within and between the clusters. We find that the
distribution of dark matter is well traced by the cluster galaxies, with the
brightest cluster galaxies marking out the strongest peaks in the dark matter
distribution. We also find a significant extension of the dark matter
distribution of Abell 901a in the direction of an infalling X-ray group Abell
901alpha. We present mass, mass-to-light and mass-to-stellar mass ratio
measurements of the structures and substructures that we detect. We find no
evidence for variation of the mass-to-light and mass-to-stellar mass ratio
between the different clusters. We compare our space-based lensing analysis
with an earlier ground-based lensing analysis of the supercluster to
demonstrate the importance of space-based imaging for future weak lensing dark
matter 'observations'.


title:
On the Logarithmic Asymptotics of the Sixth Painleve' Equation (Summer
  2007)

abstract:
  We study the solutions of the sixth Painlev\'e equation with a logarithmic
asymptotic behavior at a critical point. We compute the monodromy group
associated to the solutions by the method of monodromy preserving deformations
and we characterize the asymptotic behavior in terms of the monodromy itself.


title:
Hierarchical selection of variables in sparse high-dimensional
  regression

abstract:
  We study a regression model with a huge number of interacting variables. We
consider a specific approximation of the regression function under two
ssumptions: (i) there exists a sparse representation of the regression function
in a suggested basis, (ii) there are no interactions outside of the set of the
corresponding main effects. We suggest an hierarchical randomized search
procedure for selection of variables and of their interactions. We show that
given an initial estimator, an estimator with a similar prediction loss but
with a smaller number of non-zero coordinates can be found.


title:
Atomistic Non-equilibrium Green s Function Simulations of Graphene
  Nano-Ribbons in the Quantum Hall Regime

abstract:
  The quantum Hall effect in Graphene nano-ribbons (GNR) is investigated with
the non-equilibrium Green s function (NEGF) based quantum transport model in
the ballistic regime. The nearest neighbor tight-binding model based on pz
orbital constructs the device Hamiltonian. GNRs of different edge geometries
(Zigzag and Armchair) are considered. The magnetic field is included in both
the channels and contact through Peierls substitution. Efficient algorithms for
calculating the surface Green function are used to save computation time while
simulating realistically large dimensions comparable to those used in
experiments. Hall resistance calculations exactly reproduce the quantum Hall
plateaus observed in the experiments. Use of large dimensions in the simulation
is crucial in order to capture the quantum Hall effect in magnetic fields
within experimentally relevant 10-20T.


title: Topological A-Type Models with Flux

abstract:
  We study deformations of the A-model in the presence of fluxes, by which we
mean rank-three tensors with antisymmetrized upper/lower indices, using the
AKSZ construction. Generically these are topological membrane models, and we
show that the fluxes are related to deformations of the Courant bracket which
generalize the twist by a closed 3-from $H$, in the sense that satisfying the
AKSZ master equation implies the integrability conditions for an almost
generalized complex structure with respect to the deformed Courant bracket. In
addition, the master equation imposes conditions on the fluxes that generalize
$dH=0$. The membrane model can be defined on a large class of $U(m)$- and $U(m)
\times U(m)$-structure manifolds, including geometries inspired by $(1,1)$
supersymmetric $\sigma$-models with additional supersymmetries due to almost
complex (but not necessarily complex) structures in the target space.
Furthermore, we show that the model can be defined on three particular
half-flat manifolds related to the Iwasawa manifold.
  When only $H$-flux is turned on it is possible to obtain a topological string
model, which we do for the case of a Calabi-Yau with a closed 3-form turned on.
The simplest deformation from the A-model is due to the $(2,0)+ (0,2)$
component of a non-trivial $b$-field. The model is generically no longer
evaluated on holomorphic maps and defines new topological invariants.
Deformations due to $H$-flux can be more radical, completely preventing
auxiliary fields from being integrated out.


title:
Detecting maximally entangled states without making the Schmidt
  decomposition

abstract:
  The bipartite entanglement of a pure quantum state is known to be
characterized by its Schmidt decomposition. In particular the state is
maximally entangled when all the Schmidt coefficients are equal. We point out a
convenient method which always yields a single analytical condition for the
state to be maximally entangled, in terms of its expansion coefficients in any
basis. The method works even when the Schmidt coefficients cannot be calculated
analytically, and does not require their calculation. As an example this
technique is used to derive the Bell basis for a system of two qubits. In a
second example the technique shows a particular state to \textit{never} be
maximally entangled, a general conclusion that cannot be reached using the
Schmidt decomposition.


title:
Impact of silver addition on room temperature magneto-resistance in
  La0.7Ba0.3MnO3 (LBMO): Agx (x = 0.0, 0.1, 0.2, 0.3, 0.4)

abstract:
  La0.7Ba0.3MnO3 (LBMO):Agx (x = 0.0, 0.1, 0.2, 0.3, and 0.4) composites are
synthesized by solid-state reaction route, the final sintering temperatures are
varied from 1300 (LBMO1300Ag) to 1400 0C (LBMO1400Ag), and their physical
properties are compared as a function of temperature and Ag content. All
samples are crystallized in single phase accompanied by some distortion in main
structural phase peaks at higher angles with increase in silver content. Though
the lattice parameters (a, c) decrease, the b increases slightly with an
increase in Ag content. The scanning electron micrographs (SEM) showed better
grains morphology in terms of size and diffusion of grain boundaries with an
increase in Ag content. In both LBMO1300Ag and LBMO1400Ag series the metal
insulator transition (TMI) and accompanied paramagnetic-ferromagnetic
transition (TC) temperatures are decreased with increase in Ag content. The
sharpness of MI transition, defined by temperature coefficient of resistance
(TCR), is improved for Ag added samples. At a particular content of Ag(0.3),
the TMI and TC are tuned to 300K and maximum magneto-resistance at 7Tesla
applied field (MR7T) of up to 55% is achieved at this temperature, which is
more than double to that as observed for pure samples of the both 1300 and 1400
0C series at same temperature. The MR7T is further increased to above 60% for
LBMOAg(0.4) samples, but is at 270K. The MR7T is measured at varying
temperatures of 5, 100, 200, 300, and 400K in varying fields from +/- 7 Tesla,
which exhibits U and V type shapes. Summarily, the addition of Ag in LBMO
improves significantly the morphology of the grains and results in better
physical properties of the parent manganite system.


title:
On the possible wave-packet collapse induced by topological
  disconnectivity and experimental suggestions

abstract:
  The purpose of this paper is to explore the possibility of a wave-packet
collapse induced by topological disconnectivity, based on the discussions of
the wave-corpuscle duality. Several experimental suggestions are proposed to
test this sort of wave-packet collapse based on quantum interference.


title: Disks around massive young stellar objects: are they common?

abstract:
  We present K-band polarimetric images of several massive young stellar
objects at resolutions $\sim$ 0.1-0.5 arcsec. The polarization vectors around
these sources are nearly centro-symmetric, indicating they are dominating the
illumination of each field. Three out of the four sources show elongated
low-polarization structures passing through the centers, suggesting the
presence of polarization disks. These structures and their surrounding
reflection nebulae make up bipolar outflow/disk systems, supporting the
collapse/accretion scenario as their low-mass siblings. In particular, S140
IRS1 show well defined outflow cavity walls and a polarization disk which
matches the direction of previously observed equatorial disk wind, thus
confirming the polarization disk is actually the circumstellar disk. To date, a
dozen massive protostellar objects show evidence for the existence of disks;
our work add additional samples around MYSOs equivalent to early B-type stars.


title: Over-Improved Stout-Link Smearing

abstract:
  A new over-improved stout-link smearing algorithm, designed to stabilise
instanton-like objects, is presented. A method for quantifying the selection of
the over-improvement parameter, $\epsilon$, is demonstrated. The new smearing
algorithm is compared with the original stout-link smearing, and Symanzik
improved smearing through calculations of the topological charge and
visualisations of the topological charge density.


title:
Geometrical Frustration in Two Dimensions: Idealizations and
  Realizations of a Hard Disc Fluid in Negative Curvature

abstract:
  We examine a simple hard disc fluid with no long range interactions on the
two dimensional space of constant negative Gaussian curvature, the hyperbolic
plane. This geometry provides a natural mechanism by which global crystalline
order is frustrated, allowing us to construct a tractable model of disordered
monodisperse hard discs. We extend free area theory and the virial expansion to
this regime, deriving the equation of state for the system, and compare its
predictions with simulation near an isostatic packing in the curved space.
Additionally, we investigate packing and dynamics on triply periodic,
negatively curved surfaces with an eye toward real biological and polymeric
systems.


title:
The c2d Spitzer Spectroscopic Survey of Ices Around Low-Mass Young
  Stellar Objects: I. H2O and the 5-8 um Bands

abstract:
  With the goal to study the physical and chemical evolution of ices in
solar-mass systems, a spectral survey is conducted of a sample of 41 low
luminosity YSOs using 3-38 um Spitzer and ground-based spectra. The long-known
6.0 and 6.85 um bands are detected toward all sources, with the Class 0-type
YSOs showing the deepest bands ever observed. In almost all sources the 6.0 um
band is deeper than expected from the bending mode of pure solid H2O. The depth
and shape variations of the remaining 5-7 um absorption indicate that it
consists of 5 independent components, which, by comparison to laboratory
studies, must be from at least 8 different carriers. Simple species are
responsible for much of the absorption in the 5-7 um region, at abundances of
1-30% for CH3OH, 3-8% for NH3, 1-5% for HCOOH, ~6% for H2CO, and ~0.3% for
HCOO- with respect to solid H2O. The 6.85 um band likely consists of one or two
carriers, of which one is less volatile than H2O because its abundance relative
to H2O is enhanced at lower H2O/tau_9.7 ratios. It does not survive in the
diffuse interstellar medium (ISM), however. The similarity of the 6.85 um bands
for YSOs and background stars indicates that its carrier(s) must be formed
early in the molecular cloud evolution. If an NH4+ salt is the carrier its
abundance with respect to solid H2O is typically 7%, and low temperature
acid-base chemistry or cosmic ray induced reactions must have been involved in
its formation. Possible origins are discussed for the carrier of an enigmatic,
very broad absorption between 5 and 8 um. Finally, all the phenomena observed
for ices toward massive YSOs are also observed toward low mass YSOs, indicating
that processing of the ices by internal ultraviolet radiation fields is a minor
factor in the early chemical evolution of the ices. [abridged]


title: Projective normality of quotient varieties modulo finite groups

abstract:
  In this note, we prove that for any finite dimensional vector space $V$ over
an algebraically closed field $k$, and for any finite subgroup $G$ of $GL(V)$
which is either solvable or is generated by pseudo reflections such that the
$|G|$ is a unit in $k$, the projective variety $\mathbb P(V)/G$ is projectively
normal with respect to the descent of $\mathcal O(1)^{\otimes |G|}$.


title: B meson Dileptonic Decays in NMSSM with a Light CP-odd Higgs Boson

abstract:
  In the next-to-minimal supersymmetric model (NMSSM) a light CP-odd Higgs
boson is so far allowed by current experiments, which, together with a large
tan-beta, may greatly enhance the rare dileptonic decays B-> X_s l^+ l^- and
B_s-> l^+ l^- gamma. We examine these decays paying special attention to the
new operator allowed by the light CP-odd Higgs boson. We find that in the
parameter space allowed by current experiments like LEP II and b-> s gamma, the
branching ratios of these rare decays can be greatly enhanced and thus the
existing experimental data on B-> X_s mu^+ mu^- can further stringently
constrain the parameter space (especially the region with a super-light CP-odd
Higgs boson and large tan-beta). In the surviving parameter space we give the
predictions for other dileptonic decay branching ratios and also show the
results for the forward-backward asymmetry.


title: The luminosity -- halo-mass relation for brightest cluster galaxies

abstract:
  We examine the central-galaxy luminosity -- host-halo mass relation for 54
Brightest Group Galaxies (BGGs) and 92 Brightest Cluster Galaxies (BCGs) at
z<0.1 and present the first measurement of this relation for a sample of known
BCGs at 0.1<z<0.8 (average z~0.3). At z<0.1 we find L_K \propto
M_{200}^{0.24\pm0.08} for the BCGs and the early-type BGGs in groups with
extended X-ray emission and L_K \propto M_{200}^{0.11\pm0.10} for the BCGs
alone. At 0.1<z<0.8 we find L_K \propto M_{200}^{0.28\pm0.11}. We conclude that
there is no evidence for evolution in this relationship between z<0.1 and
z<0.8: BCG growth appears to still be limited by the timescale for dynamical
friction at these earlier times, not proceeding according to the predictions of
current semi-analytic models.


title:
Mott transition in VO2 revealed by infrared spectroscopy and
  nano-imaging

abstract:
  Electrons in correlated insulators are prevented from conducting by Coulomb
repulsion between them. When an insulator-to-metal transition is induced in a
correlated insulator by doping or heating, the resulting conducting state can
be radically different from that characterized by free electrons in
conventional metals. We report on the electronic properties of a prototypical
correlated insulator vanadium dioxide (VO2) in which the metallic state can be
induced by increasing temperature. Scanning near-field infrared microscopy
allows us to directly image nano-scale metallic puddles that appear at the
onset of the insulator-to-metal transition. In combination with far-field
infrared spectroscopy, the data reveal the Mott transition with divergent
quasiparticle mass in the metallic puddles. The experimental approach employed
here sets the stage for investigations of charge dynamics on the nanoscale in
other inhomogeneous correlated electron systems.


title: Remarks on the two-dimensional power correction in the soft wall model

abstract:
  We present a direct derivation of the two-point correlation function of the
vector current in the soft wall model by using the AdS/CFT dictionary. The
resulting correlator is exactly the same as the one previously obtained from
dispersion relation with the same spectral function as in this model. The
coefficient $C_2$ of the two-dimensional power correction is found to be
$C_2=-c/2$ with $c$ the slope of the Regge trajectory, rather than $C_2=-c/3$
derived from the strategy of first quantized string theory. Taking the slope of
the $\rho$ trajectory $c\approx0.9{GeV}^2$ as input, we then get
$C_2\approx-0.45{GeV}^2$. The gluon condensate is found to be
$<\alpha_sG^2>\approx0.064{GeV}^4$, which is almost identical to the QCD sum
rule estimation. By comparing these two equivalent derivation of the correlator
of scalar glueball operator, we demonstrate that the two-dimensional correction
can't be eliminated by including the non-leading solution in the
bulk-to-boundary propagator, as was done in \cite{Colangelo2}. In other words,
the two-dimensional correction does exist in the scalar glueball case. Also it
is manifest by using the dispersion relation that the minus sign of gluon
condensate and violation of the low energy theorem are related to the
subtraction scheme.


title:
Comment on "Design of a broadband highly dispersive pure silica photonic
  crystal fiber" by Subbaraman et al

abstract:
  In a recent paper, Subbaraman et al report a theoretical and numerical study
of highly dispersive pure silica photonic crystal fiber supporting
group-velocity dispersion exceeding -2*10^4 ps/nm/km. This comment argues that
the authors only consider one out of the two sides of the same coin, by not
taking the corresponding beating length into account.


title: The Half-Integer Charged Particles of the Orbifold Models

abstract:
  In this paper, we consider half-integer charged particles predicted by models
of orbifold compactification of the $E_8\times E_8$ heterotic string theory. We
find that it is possible for half-integer charged particles to exist in our
universe, and the location of half-interger charged particles in a galaxy
should be in the centers of the galaxy. By qualitative analysis, we find
half-interger charged particles may be helpful in explaining the formation of
SMBH at the large redshift and solving the UHECR puzzle.


title: Direct string magnetic gradiometer for space applications

abstract:
  Recently, a novel Direct String Magnetic Gradiometer (DSMG) has been
developed, where a vibrating wire, driven by an AC current, is used as a single
sensitive element. It is designed to directly measure the local off-diagonal
components of the magnetic gradient tensor, Bxz, Byz and Bxy, provided the
distance to an object creating magnetic anomalies is much larger than the
length of the string. This requirement is well satisfied in space, if the
sensor is deployed from a satellite platform orbiting near the planet under
surveillance. Current instruments operating at $1{kPa}$ pressure achieve
sensitivity of $1.8 \times 10^{-10}{T}/{m}$ in the band $0.0001{Hz}$ to
$0.1{Hz}$. In this paper we show that proposed modifications to the current
gradiometer design, specifically aimed at the deployment in space, could have a
magnetic gradient sensitivity better than $10^{-13}{T}/{m}/\sqrt{Hz}$ in the
frequency range of interest for specific missions both for fundamental research
and for such applications as geophysical exploration on Mars and other solar
system planets. Also, by combining a few single-axis magnetic gradiometer
modules, it is possible to deploy a full tensor magnetic gradiometer.


title: Hidden Grassmann Structure in the XXZ Model II: Creation Operators

abstract:
  In this article we unveil a new structure in the space of operators of the
XXZ chain. We consider the space of all quasi-local operators, which are
products of the disorder field with arbitrary local operators. In analogy with
CFT the disorder operator itself is considered as primary field. In our
previous paper, we have introduced the annhilation operators which mutually
anti-commute and kill the primary field. Here we construct the creation
counterpart and prove the canonical anti-commutation relations with the
annihilation operators. We show that the ground state averages of quasi-local
operators created by the creation operators from the primary field are given by
determinants.


title:
New developments in the theory of Groebner bases and applications to
  formal verification

abstract:
  We present foundational work on standard bases over rings and on Boolean
Groebner bases in the framework of Boolean functions. The research was
motivated by our collaboration with electrical engineers and computer
scientists on problems arising from formal verification of digital circuits. In
fact, algebraic modelling of formal verification problems is developed on the
word-level as well as on the bit-level. The word-level model leads to Groebner
basis in the polynomial ring over Z/2n while the bit-level model leads to
Boolean Groebner bases. In addition to the theoretical foundations of both
approaches, the algorithms have been implemented. Using these implementations
we show that special data structures and the exploitation of symmetries make
Groebner bases competitive to state-of-the-art tools from formal verification
but having the advantage of being systematic and more flexible.


title: Light Transition Metal Monatomic Chains

abstract:
  In this paper we investigated structural, electronic and magnetic properties
of 3d (light) transition metal (TM) atomic chains using first-principles
pseudopotential plane wave calculations. Periodic linear, dimerized linear and
planar zigzag chain structures and their short segments consisting of finite
number of atoms have been considered. Like Cu, the periodic, linear chains of
Mn, Co and Ni correspond to a local shallow minimum. However, for most of the
infinite periodic chains, neither linear nor dimerized linear structures are
favored; to lower their energy the chains undergo a structural transformation
to form planar zigzag and dimerized zigzag geometry. Dimerization in both
infinite and finite chains are much stronger than the usual Peierls distortion
and appear to depend on the number of 3d-electrons. As a result of
dimerization, a significant energy lowering occurs which, in turn, influences
the stability and physical properties. Metallic linear chain of Vanadium
becomes half-metallic upon dimerization. Infinite linear chain of Scandium also
becomes half-metallic upon transformation to zigzag structure. An interplay
between the magnetic ground state and atomic as well as electronic structure of
the chain has been revealed. The end effects influence the geometry, energetics
and magnetic ground state of the finite chains. Structure optimization
performed using noncollinear approximation indicates significant differences
from the collinear approximation. Variation of the cohesive energy of infinite
and finite-size chains with respect to the number of 3d-electrons are found to
mimic the bulk behavior pointed out by Friedel. The spin-orbit coupling of
finite chains are found to be negligibly small.


title: Corpus sp{\'e}cialis{\'e} et ressource de sp{\'e}cialit{\'e}

abstract:
  "Semantic Atlas" is a mathematic and statistic model to visualise word senses
according to relations between words. The model, that has been applied to
proximity relations from a corpus, has shown its ability to distinguish word
senses as the corpus' contributors comprehend them. We propose to use the model
and a specialised corpus in order to create automatically a specialised
dictionary relative to the corpus' domain. A morpho-syntactic analysis
performed on the corpus makes it possible to create the dictionary from
syntactic relations between lexical units. The semantic resource can be used to
navigate semantically - and not only lexically - through the corpus, to create
classical dictionaries or for diachronic studies of the language.


title: Simulations of galactic disks including a dark baryonic component

abstract:
  $\Lambda$CDM numerical simulations predict that the "missing baryons" reside
in a Warm-Hot gas phase in the over-dense cosmic filaments. However, there are
now several theoretical and observational arguments that support the fact that
galactic disks may be more massive than usually thought, containing a
substantial fraction of the "missing baryons". Hereafter, we present new N-body
simulations of galactic disks, where the gas content has been multiplied by a
factor 5. The stability of the disk is ensured by assuming that the ISM is
composed out of two partially coupled phases, a warm phase, corresponding the
observed CO and HI gas and a cold collisionless phase corresponding to the
unseen baryons.


title: A Geometric Hamilton-Jacobi Theory for Classical Field Theories

abstract:
  In this paper we extend the geometric formalism of the Hamilton-Jacobi theory
for hamiltonian mechanics to the case of classical field theories in the
framework of multisymplectic geometry and Ehresmann connections.


title: Relativistic Quantum Coulomb Law

abstract:
  The relativistic quantum mechanics equations for the electromagnetic
interaction are propososed.


title:
Rings over which the class of Gorenstein flat modules is closed under
  extensions

abstract:
  A ring $R$ is called left GF-closed, if the class of all Gorenstein flat left
$R$-modules is closed under extensions. The class of left GF-closed rings
includes strictly the one of right coherent rings and the one of rings of
finite weak dimension.
  In this paper, we investigate the Gorenstein flat dimension over left
GF-closed rings. Namely, we generalize the fact that the class of all
Gorenstein flat left modules is projectively resolving over right coherent
rings to left GF-closed rings. Also, we generalize the characterization of
Gorenstein flat left modules (then of Gorenstein flat dimension of left
modules) over right coherent rings to left GF-closed rings. Finally, using
direct products of rings, we show how to construct a left GF-closed ring that
is neither right coherent nor of finite weak dimension.


title:
GMASS Ultradeep Spectroscopy of Galaxies at 1.4<z<2. II. Superdense
  passive galaxies: how did they form and evolve ?

abstract:
  We combine ultradeep optical spectroscopy from the GMASS project ("Galaxy
Mass Assembly ultradeep Spectroscopic Survey") with GOODS multi-band photometry
and HST imaging to study a sample of passive galaxiesat 1.39<z<1.99 selected at
4.5 microns. A stacked spectrum with an equivalent integration time of ~500
hours was obtained is publicly released. The spectral and photometric SED
properties indicate very weak or absent star formation, moderately old stellar
ages of ~1 Gyr (for solar metallicity) and stellar masses in the range of
10^{10-11} solar masses, thus implying that the major star formation and
assembly processes for these galaxies occurred at z>2. These galaxies have
morphologies that are predominantly compact and spheroidal.However, their sizes
(R_e <~ 1 kpc) are much smaller than those of spheroids in the present--day
Universe. Their stellar mass surface densities are consequently higher by ~1
dex if compared to spheroids at z~0 with the same mass. Their rest-frame B-band
surface brightness scales with the effective radius, but the offset with
respect to the surface brightness of the local Kormendy relation is too large
to be explained by simple passive evolution. At z~1, a larger fraction of
passive galaxies follows the z~0 size -- mass relation. Superdense relics with
R_e~1 kpc are extremely rare at z~0 with respect to z>1, and absent if R_e<1
kpc. Because of the similar sizes and mass densities, we suggest that the
superdense passive galaxies at 1<z<2 are the remnants of the powerful
starbursts occurring in submillimeter--selected galaxies at z>2. The results
are compared with theoretical models and the main implications discussed in the
framework of massive galaxy formation and evolution.


title: Capacity of the Discrete-Time AWGN Channel Under Output Quantization

abstract:
  We investigate the limits of communication over the discrete-time Additive
White Gaussian Noise (AWGN) channel, when the channel output is quantized using
a small number of bits. We first provide a proof of our recent conjecture on
the optimality of a discrete input distribution in this scenario. Specifically,
we show that for any given output quantizer choice with K quantization bins
(i.e., a precision of log2 K bits), the input distribution, under an average
power constraint, need not have any more than K + 1 mass points to achieve the
channel capacity. The cutting-plane algorithm is employed to compute this
capacity and to generate optimum input distributions. Numerical optimization
over the choice of the quantizer is then performed (for 2-bit and 3-bit
symmetric quantization), and the results we obtain show that the loss due to
low-precision output quantization, which is small at low signal-to-noise ratio
(SNR) as expected, can be quite acceptable even for moderate to high SNR
values. For example, at SNRs up to 20 dB, 2-3 bit quantization achieves 80-90%
of the capacity achievable using infinite-precision quantization.


title: Transport in Silicon Nanowires: Role of Radial Dopant Profile

abstract:
  We consider the electronic transport properties of phosphorus (P) doped
silicon nanowires (SiNWs). By combining ab initio density functional theory
(DFT) calculations with a recursive Green's function method, we calculate the
conductance distribution of up to 200 nm long SiNWs with different
distributions of P dopant impurities. We find that the radial distribution of
the dopants influences the conductance properties significantly: Surface doped
wires have longer mean-free paths and smaller sample-to-sample fluctuations in
the cross-over from ballistic to diffusive transport. These findings can be
quantitatively predicted in terms of the scattering properties of the single
dopant atoms, implying that relatively simple calculations are sufficient in
practical device modeling


title:
3D Lya radiation transfer. II. Fitting the Lyman break galaxy MS
  1512-cB58 and implications for Lya emission in high-z starbursts

abstract:
  Using our 3D Lya radiation transfer code, we compute the radiation transfer
of Lya and UV continuum photons including dust. Observational constraints on
the neutral gas (column density, kinematics, etc.) are taken from other
analysis of this object. RESULTS: The observed Lya profile of MS 1512--cB58 is
reproduced for the first time taking radiation transfer and all observational
constraints into account. The observed absorption profile is found to result
naturally from the observed amount of dust and the relatively high HI column
density. Radiation transfer effects and suppresion by dust transform a strong
intrinsic Lya emission with EW(Lya)>~ 60 Ang into the observed faint superposed
Lya emission peak. We propose that the vast majority of LBGs have intrinsically
EW(Lya)~60-80 Ang or larger, and that the main physical parameter responsible
for the observed variety of Lya strengths and profiles in LBGs is N_H and the
accompanying variation of the dust content. Observed EW(Lya) distributions, Lya
luminosity functions, and related quantities must therefore be corrected for
radiation transfer and dust effects. The implications from our scenario on the
duty-cycle of Lya emitters are also discussed.


title: Few layers graphene on 6H-SiC(000-1): an STM study

abstract:
  We have analyzed by Scanning Tunnelling Microscopy (STM) thin films made of
few (3-5) graphene layers grown on the C terminated face of 6H-SiC in order to
identify the nature of the azimuthal disorder reported in this material. We
observe superstructures which are interpreted as Moir\'e patterns due to a
misorientation angle between consecutive layers. The presence of stacking
faults is expected to lead to electronic properties reminiscent of single layer
graphene even for multilayer samples. Our results indicate that this apparent
electronic decoupling of the layers can show up in STM data.


title:
On stability, persistence and Hopf bifurcation of fractional order
  dynamical system

abstract:
  This is a preliminary study for bifurcation in fractional order dynamical
systems. Stability, persistence and hopf bifurcation are studied. Some studies
are also done for functional equations.


title: The Detailed Evolution of E+A Galaxies into Early Types

abstract:
  Post-starburst, or E+A galaxies, are the best candidates for galaxies in
transition from being gas-rich and star-forming to gas-poor and
passively-evolving via galaxy-galaxy mergers. To determine what E+A galaxies
become after their young stellar populations fade away, we present the detailed
morphologies of 21 E+As using HST images. We find that E+As are similar to
early types in that they have large bulge fractions (median B/T = 0.59), high
Sersic index (n > 4), and high concentration indices (C > 4.3). The large
fraction (70%) of E+As with positive color gradients (i.e., bluer nuclei)
indicates that the young stellar populations are more concentrated than the old
populations. We show that these positive color gradients can evolve into the
negative gradients typical in E/S0s if the central parts of these galaxies are
metal enhanced. E+A galaxies stand apart from the E/S0s in the edge-on
projection of the Fundamental Plane, implying that E+As have, on average, a M/L
that is ~3.8 times smaller than that of E/S0s. The tilt of the E+A FP indicates
that the variation among stellar populations in these galaxies is closely tied
to their structural parameters such that smaller or less massive galaxies have
smaller M/L. We find a population of unresolved compact sources in nine E+As
(45%). Their colors and luminosities are consistent with the hypothesis that
these are newly formed star clusters. The bright end of the cluster LF is
fainter in redder E+A's, suggesting that the young star cluster systems have
faded or been disrupted as the merger remnant aged. In summary, the
morphologies, color profiles, scaling relations, and cluster populations are
all consistent with the hypothesis that E+As galaxies are the results of
mergers that evolve into early-type galaxies.


title:
Relevance of ferromagnetic correlations for the Electron Spin Resonance
  in Kondo lattice systems

abstract:
  Electron Spin Resonance (ESR) measurements of the ferromagnetic Kondo lattice
system CeRuPO show a well defined ESR signal which is related to the magnetic
properties of the Ce3+ moment. In contrast, no ESR signal could be observed in
the antiferromagnetic homologue CeOsPO. Additionally, we detect an ESR signal
in a further ferromagnetic Yb compound, YbRh, while it was absent in a number
of Ce or Yb intermetallic compounds with dominant antiferromagnetic exchange,
independently of the presence of a strong Kondo interaction or the proximity to
a (quantum) critical point. Thus, the observation of an ESR signal in a Kondo
lattice is neither specific to Yb nor to the proximity of a quantum critical
point, but seems to be connected to the presence of ferromagnetic fluctuations.
These conclusions not only provide a basic concept to understand the ESR in
Kondo lattice systems even well below the Kondo temperature as observed in the
heavy fermion metal YbRh2Si2 but point out ESR as a prime method to investigate
directly the spin dynamics of the Kondo ion.


title:
Tunneling anisotropic magnetoresistance in multilayer-(Co/Pt)/AlOx/Pt
  structures

abstract:
  We report observations of tunneling anisotropic magnetoresitance (TAMR) in
vertical tunnel devices with a ferromagnetic multilayer-(Co/Pt) electrode and a
non-magnetic Pt counter-electrode separated by an AlOx barrier. In stacks with
the ferromagnetic electrode terminated by a Co film the TAMR magnitude
saturates at 0.15% beyond which it shows only weak dependence on the magnetic
field strength, bias voltage, and temperature. For ferromagnetic electrodes
terminated by two monolayers of Pt we observe order(s) of magnitude enhancement
of the TAMR and a strong dependence on field, temperature and bias. Discussion
of experiments is based on relativistic ab initio calculations of magnetization
orientation dependent densities of states of Co and Co/Pt model systems.


title:
GMASS Ultradeep Spectroscopy of Galaxies at redshift z~2. I. The stellar
  metallicity

abstract:
  Context: Galaxy metallicities have been measured to redshift z~2 by gas-phase
oxygen abundances of the interstellar medium using the R23 and N2 methods.
Galaxy stellar metallicities provide crucial data for chemical evolution models
but have not been assessed reliably much outside the local Universe. Aims: We
determine the iron-abundance, stellar metallicity of star-forming galaxies
(SFGs) at redshift z~2, observed as part of the Galaxy Mass Assembly ultra-deep
Spectroscopic Survey (GMASS). Methods: We compute the equivalent width of a
rest-frame mid-ultraviolet, photospheric absorption-line index, the 1978 index
found to vary monotonically with stellar metallicity by Rix and collaborators.
We normalise and combine 75 SFG spectra from the GMASS survey to produce a
spectrum corresponding to a total integration time 1652.5 hours (and a
signal-to-noise ratio ~100 for our 1.5 angstrom binning) of FORS2 spectroscopic
observations at the Very Large Telescope. Results: We measure an
iron-abundance, stellar metallicity of log (Z/Zsolar) = -0.574+/-0.159 for our
spectrum representative of a galaxy of stellar mass 9.4 x 10^9 Msolar assuming
a Chabrier IMF. We find that the R04 model SFG spectrum for log (Z/Zsolar) =
-0.699 solar metallicity provides the best description of our GMASS coadded
spectrum. For similar galaxy stellar mass, our stellar metallicity is ~0.25 dex
lower than the oxygen-abundance, gas-phase metallicity quantified by Erb and
collaborators for UV-selected star-forming galaxies at z=2. Conclusions: We
conclude that we are witnessing the establishment of a light-element
overabundance in galaxies as they are being formed at redshift z~2. Our
measurements are reminiscent of the alpha-element enhancement seen in
low-redshift, galactic bulges and early-type galaxies. (Abridged)


title:
Non-perturbative QED Model with Dressed States to Tackle HHG in
  Ultrashort Intense Laser Pulses

abstract:
  A generalization of non-perturbative QED model for high harmonic generation
is developed for the multi-mode optical field case. By introducing
classical-field-dressed quantized Volkov states analytically, a formula to
calculate HHG for hydrogen-like atom in ultrashort intense laser pulse is
obtained, which has a simple intuitive interpretation. The dressed state QED
model indicates a new perspective to understand HHG, for example, the presence
of the weak even-order harmonic photons, which has been verified by both
theoretical analysis and numerical computation. Long wavelength approximation
and strong field approximation are involved in the development of the
formalism.


title: Markov partitions reflecting the geometry of x2,x3

abstract:
  We give an explicit geometric description of the $\times2,\times3$ system,
and use his to study a uniform family of Markov partitions related to those of
Wilson and Abramov. The behaviour of these partitions is stable across
expansive cones and transitions in this behaviour detects the non-expansive
lines.


title:
Imprecise probability trees: Bridging two theories of imprecise
  probability

abstract:
  We give an overview of two approaches to probability theory where lower and
upper probabilities, rather than probabilities, are used: Walley's behavioural
theory of imprecise probabilities, and Shafer and Vovk's game-theoretic account
of probability. We show that the two theories are more closely related than
would be suspected at first sight, and we establish a correspondence between
them that (i) has an interesting interpretation, and (ii) allows us to freely
import results from one theory into the other. Our approach leads to an account
of probability trees and random processes in the framework of Walley's theory.
We indicate how our results can be used to reduce the computational complexity
of dealing with imprecision in probability trees, and we prove an interesting
and quite general version of the weak law of large numbers.


title:
Random Wave Functions with boundary and normalization constraints:
  Quantum statistical physics meets quantum chaos

abstract:
  We present an improved version of Berry's ansatz able to incorporate exactly
the existence of boundaries and the correct normalization of the eigenfunction
into an ensemble of random waves. We then reformulate the Random Wave
conjecture showing that in its new version it is a statement about the
universal nature of eigenfunction fluctuations in systems with chaotic
classical dynamics. The emergence of the universal results requires the use of
both semiclassical methods and a new expansion for a very old problem in
quantum statistical physics

categories: nlin.CD cond-mat.mes-hall math-ph math.MP quant-ph


title:
Kinematic Sunyaev-Zeldovich Cosmic Microwave Background Temperature
  Anisotropies Generated by Gas in Cosmic Structures

abstract:
  If the gas in filaments and halos shares the same velocity field than the
luminous matter, it will generate measurable temperature anisotropies due to
the Kinematic Sunyaev-Zeldovich effect. We compute the distribution function of
the KSZ signal produced by a typical filament and show it is highly
non-gaussian. The combined contribution of the Thermal and Kinematic SZ effects
of a filament of size $L\simeq 5$Mpc and electron density $n_e\simeq
10^3m^{-3}$ could explain the cold spots of $\delta\sim -200\mu$K on scales of
30' found in the Corona Borealis Supercluster by the VSA experiment. PLANCK,
with its large resolution and frequency coverage, could provide the first
evidence of the existence of filaments in this region. The KSZ contribution of
the network of filaments and halo structures to the radiation power spectrum
peaks around $l\sim 400$, a scale very different from that of clusters of
galaxies, with a maximum amplitude $l(l+1)C_l/2\pi\sim 10-25 (\mu K)^2$,
depending on model parameters, i.e., $\sigma_8$ and the Jeans length. About 80%
of the signal comes from filaments with redshift $z\le 0.1$. Adding this
component to the intrinsic Cosmic Microwave Background temperature anisotropies
of the concordance model improves the fit to WMAP 3yr data by
$\Delta\chi^2\simeq 1$. The improvement is not statistically significant but a
more systematic study could demonstrate that gas could significantly contribute
to the anisotropies measured by WMAP.


title: Dynamics and chaos in the unified scalar field Cosmology

abstract:
  We study the dynamics of the closed scalar field FRW cosmological models in
the framework of the so called Unified Dark Matter (UDM) scenario. Performing a
theoretical as well as a numerical analysis we find that there is a strong
indication of chaos in agreement with previous studies. We find that a positive
value of the spatial curvature is essential for the appearance of chaoticity,
though the Lyapunov number seems to be independent of the curvature value.
Models that are close to flat exhibit a chaotic behavior after a long time
while pure flat models do not exhibit any chaos. Moreover, we find that some of
the semiflat models in the UDM scenario exhibit similar dynamical behavior with
the Lambda cosmology despite their chaoticity.
  Finally, we compare the measured evolution of the Hubble parameter derived
from the differential ages of passively evolving galaxies with that expected in
the semiflat unified scalar field cosmology. Based on a specific set of initial
conditions we find that the UDM scalar field model matches well the
observational data.


title:
The low-energy excitation spectrum of one-dimensional dipolar quantum
  gases

abstract:
  We determine the excitation spectrum of a bosonic dipolar quantum gas in a
one-dimensional geometry, from the dynamical density-density correlation
functions simulated by means of Reptation Quantum Monte Carlo techniques. The
excitation energy is always vanishing at the first vector of the reciprocal
lattice in the whole crossover from the liquid-like at low density to the
quasi-ordered state at high density, demonstrating the absence of a roton
minimum. Gaps at higher reciprocal lattice vectors are seen to progressively
close with increasing density, while the quantum state evolves into a
quasi-periodic structure. The simulational data together with the
uncertainty-principle inequality also provide a rigorous proof of the absence
of long-range order in such a super-strongly correlated system. Our conclusions
confirm that the dipolar gas is in a Luttinger-liquid state, significantly
affected by the dynamical correlations. The connection with ongoing experiments
is also discussed.


title:
Thermodynamics of impurities in the anisotropic Heisenberg spin-1/2
  chain

abstract:
  The thermodynamics of finite open antiferromagnetic XXZ chains is studied
using field theory, Bethe Ansatz and quantum Monte Carlo methods. For the
susceptibility a parameter-free result as a function of the number of sites L
and temperature T beyond the scaling limit is derived. The limiting cases T/J
>> 1/L (J being the exchange constant), where the boundary correction shows a
logarithmically suppressed Curie behaviour, and T/J << 1/L, where a crossover
to the ground state behaviour takes place, are discussed in detail. Based on
this analysis we present a simple formula for the averaged susceptibility of a
spin-1/2 chain doped with non-magnetic impurities. We show that the effective
Curie constant has a highly non-trivial temperature dependence and shows
scaling in the low-temperature limit. Finally, corrections due to intra- and
interchain couplings and implications for experiments on Sr_2 Cu_{1-x}Pd_x
O_{3+\delta} and related compounds are discussed.


title: Renormalization of the dephasing by zero point fluctuations

abstract:
  We study the role of zero-point-fluctuations (ZPF) in dephasing at low
temperature. Unlike the Caldeira-Leggett model where the interaction is with an
homogeneous fluctuating field of force, here we consider the effect of short
range scattering by localized bath modes. We find that in presence of ZPF the
inelastic cross-section gets renormalized. Thus indirectly ZPF might contribute
to the dephasing at low temperature.


title:
Testing for Markovian Character and Modeling of Intermittency in Solar
  Wind Turbulence

abstract:
  We present results of statistical analysis of solar wind turbulence using an
approach based on the theory of Markov processes. It is shown that the
Chapman-Kolmogorov equation is approximately satisfied for the turbulent
cascade. We evaluate the first two Kramers-Moyal coefficients from experimental
data and show that the solution of the resulting Fokker-Planck equation agrees
well with experimental probability distributions. Our results suggest the
presence of a local transfer mechanism for magnetic field fluctuations in solar
wind turbulence.


title: Chameleon field and the late time acceleration of the universe

abstract:
  In the present work, it is shown that a chameleon scalar field having a
nonminimal coupling with dark matter can give rise to a smooth transition from
a decelerated to an accelerated phase of expansion for the universe. It is
surprising to note that the coupling with the chameleon scalar field hardly
affects the evolution of the dark matter sector, which still redshifts as
$a^{-3}$.


title: Faint arc-minute extended radio emission around Cygnus X-3

abstract:
  Aims. We revisit the vicinity of the microquasar Cygnus X-3 at radio
wavelengths. We aim to improve our previous search for possible associated
extended radio features/hot spots in the position angle of the Cygnus X-3
relativistic jets focusing on shorter angular scales than previously explored.
  Methods. Our work is mostly based on analyzing modern survey and archive
radio data, mainly including observations carried out with the Very Large Array
and the Ryle Telescopes. We also used deep near-infrared images that we
obtained in 2005.
  Results. We present new radio maps of the Cygnus X-3 field computed after
combining multi-configuration Very Large Array archive data at 6 cm and
different observing runs at 2 cm with the Ryle Telescope. These are probably
among the deepest radio images of Cygnus X-3 reported to date at cm
wavelengths. Both interferometers reveal an extended radio feature within a few
arc-minutes of the microquasar position, thus making our detection more
credible. Moreover, this extended emission is possibly non-thermal, although
this point still needs confirmation. Its physical connection with the
microquasar is tentatively considered under different physical scenarios. We
also report on the serendipitous discovery of a likely Fanaroff-Riley type II
radio galaxy only 3 arc-minute away from Cygnus X-3.


title: Canonical and Lie-algebraic twist deformations of Galilei algebra

abstract:
  We describe various nonrelativistic contractions of two classes of twisted
Poincare algebra: canonical one ($\theta_{\mu\nu}$-deformation) and the one
leading to Lie-algebraic models of noncommutative space-times. The cases of
contraction-independent and contraction-dependent twist parameters are
considered. We obtain five models of noncommutative nonrelativistic
space-times, in particular, two new Lie-algebraic nonrelativistic deformations
of space-time, respectively, with quantum time/classical space and with quantum
space/classical time.


title:
Adjamagbo Determinant and Serre conjecture for linear groups over Weyl
  algebras

abstract:
  Thanks to the theory of determinants over an Ore domain, also called
Adjamagbo determinant by the Russian school of non commutative algebra, we
extend to any Weyl algebra over a field of characteristic zero Suslin theorem
solving what Suslin himself called the $K_1$-analogue of the well-known Serre
Conjecture and asserting that for any integer $n$ greater than 2, any $n$ by
$n$ matrix with coefficients in any algebra of polynomials over a field and
with determinant one is the product of elementary matrices with coefficients in
this algebra


title: Hybrid Decoding of Finite Geometry LDPC Codes

abstract:
  For finite geometry low-density parity-check codes, heavy row and column
weights in their parity check matrix make the decoding with even Min-Sum (MS)
variants computationally expensive. To alleviate it, we present a class of
hybrid schemes by concatenating a parallel bit flipping (BF) variant with an
Min-Sum (MS) variant. In most SNR region of interest, without compromising
performance or convergence rate, simulation results show that the proposed
hybrid schemes can save substantial computational complexity with respect to MS
variant decoding alone. Specifically, the BF variant, with much less
computational complexity, bears most decoding load before resorting to MS
variant. Computational and hardware complexity is also elaborated to justify
the feasibility of the hybrid schemes.


title:
Stochastic processes and their spectral representations over
  non-archimedean fields

abstract:
  The article is devoted to stochastic processes with values in finite- and
infinite-dimensional vector spaces over infinite fields $\bf K$ of zero
characteristics with non-trivial non-archimedean norms. For different types of
stochastic processes controlled by measures with values in $\bf K$ and in
complete topological vector spaces over $\bf K$ stochastic integrals are
investigated. Vector valued measures and integrals in spaces over $\bf K$ are
studied. Theorems about spectral decompositions of non-archimedean stochastic
processes are proved.


title: Increasing GP Computing Power via Volunteer Computing

abstract:
  This paper describes how it is possible to increase GP Computing Power via
Volunteer Computing (VC) using the BOINC framework. Two experiments using
well-known GP tools -Lil-gp & ECJ- are performed in order to demonstrate the
benefit of using VC in terms of computing power and speed up. Finally we
present an extension of the model where any GP tool or framework can be used
inside BOINC regardless of its programming language, complexity or required
operating system.


title:
Multi-color Optical Variability of the TeV Blazar Mrk 501 in the
  Low-State

abstract:
  We report results based on the monitoring of the BL Lac object Mrk 501 in the
optical (B, V and R) passbands from March to May 2000. Observations spread over
12 nights were carried out using 1.2 meter Mount Abu Telescope, India and 61 cm
Telescope at Sobaeksan Astronomy Observatory, South Korea. The aim is to study
the intra-day variability (IDV), short term variability and color variability
in the low state of the source. We have detected flux variation of 0.05 mag in
the R-band in time scale of 15 min in one night. In the B and V passbands, we
have less data points and it is difficult to infer any IDVs. Short term flux
variations are also observed in the V and R bands during the observing run. No
significant variation in color (B$-$R) has been detected but (V$-$R) shows
variation during the present observing run.
  Assuming the shortest observed time scale of variability (15 min) to
represent the disk instability or pulsation at a distance of 5 Schwarschild
radii from the black hole (BH), mass of the central BH is estimated $\sim$ 1.20
$\times$ 10$^{8} M_{\odot}$.


title: The typical countable algebra

abstract:
  We argue that it makes sense to talk about ``typical'' properties of
lattices, and then show that there is, up to isomorphism, a unique countable
lattice L* (the Fraisse limit of the class of finite lattices) that has all
``typical'' properties.
  Among these properties are: L* is simple and locally finite, every order
preserving function can be interpolated by a lattice polynomial, and every
finite lattice or countable locally finite lattice embeds into L*.
  The same arguments apply to other classes of algebras assuming they have a
Fraisse limit and satisfy the finite embeddability property.


title: The Central Region of M83

abstract:
  We combine VLT/ISAAC NIR spectroscopy with archival HST/WFPC2 and HST/NICMOS
imaging to study the central 20"x20" of M83. Our NIR indices for clusters in
the circumnuclear star-burst region are inconsistent with simple instantaneous
burst models. However, models of a single burst dispersed over a duration of 6
Myrs fit the data well and provide the clearest evidence yet of an age gradient
along the star forming arc, with the youngest clusters nearest the north-east
dust lane. The long slit kinematics show no evidence to support previous claims
of a second hidden mass concentration, although we do observe changes in
molecular gas velocity consistent with the presence of a shock at the edge of
the dust lane.


title:
Sur le Th\'eor\`eme Principal de Zariski en G\'eom\'etrie Alg\'ebrique
  et G\'eom\'etrie Analytique

abstract:
  On Zariski Main Theorem in Algebraic Geometry and Analytic Geometry. We fill
a surprising gap of Complex Analytic Geometry by proving the analogue of
Zariski Main Theorem in this geometry, i.e. proving that an holomorphic map
from an irreducible analytic space to a normal irreducible one is an open
embedding if and only if all its fibers are discrete and it induces a
bimeromorphic map on its image. We prove more generally the "Generalized
Zariski Main Theorem for analytic spaces", which claims that an holomorphic map
from an irreducible analytic space to a irreducible locally irreducible one is
an open embedding if and only if it is flat and induces a bimeromorphic map on
its image. Thanks to the "analytic criterion of regularity" of Serre-Samuel in
GAGA [12] and to "Lefschetz Principle", we finally deduce the "Generalized
Zariski Main Theorem for algebraic varieties of characteristical zero", which
claims that a morphism from such an irreducible variety to an irreducible
unibranch one is an open immersion if and only if it is birational and flat.
  -----
  Nous comblons une lacune \'etonnante de la G\'eom\'etrie Analytique Complexe
en prouvant l'analogue du Th\'eor\`eme Principal de Zariski dans cette
g\'eom\'etrie, c'est-\`a-dire en prouvant que toute application holomorphe d'un
espace analytique irreductible dans un espace analytique normal et irreductible
est un plongement ouvert si et seulement si toutes ses fibres sont discr\`etes
et si elle induit une application bim\'eromorphe sur son image. Nous prouvons
plus g\'en\'eralement le ``Th\'eor\`eme Principal de Zariski G\'en\'eralis\'e
pour les espaces analytiques'', qui affirme qu'une application holomorphe d'un
espace analytique irreductible dans un espace analytique irreductible et
localement irreductible est un plongement ouvert si et seulement si elle est
plate et induit une application bim\'eromorphe sur son image. Gr\^ace au
``crit\^ere analytique de r\'egularit\'e'' de Serre-Samuel dans GAGA
\cite{serre} et au ``Principe de Lefschetz'', nous en d\'eduisons enfin le
``Th\'eor\`eme Principal de Zariski G\'en\'eralis\'e pour les vari\'et\'es
alg\'ebriques de caract\'eristique nulle'', qui affirme qu'un morphisme d'une
telle vari\'et\'e irreductible dans une autre unibranche est une immersion
ouverte si et seulement s'il est birationnel et plat.


title: Investigating Heating and Cooling in the BCS & B55 Cluster Samples

abstract:
  We study clusters in the BCS cluster sample which are observed by Chandra and
are more distant than redshift, z>0.1. We select from this subsample the
clusters which have both a short central cooling time and a central temperature
drop, and also those with a central radio source. Six of the clusters have
clear bubbles near the centre. We calculate the heating by these bubbles and
express it as the ratio r_heat/r_cool=1.34+/-0.20. This result is used to
calculate the average size of bubbles expected in all clusters with central
radio sources. In three cases the predicted bubble sizes approximately match
the observed radio lobe dimensions.
  We combine this cluster sample with the B55 sample studied in earlier work to
increase the total sample size and redshift range. This extended sample
contains 71 clusters in the redshift range 0<z<0.4. The average distance out to
which the bubbles offset the X-ray cooling in the combined sample is at least
r_heat/r_cool=0.92+/-0.11. The distribution of central cooling times for the
combined sample shows no clusters with clear bubbles and t_cool>1.2Gyr. An
investigation of the evolution of cluster parameters within the redshift range
of the combined samples does not show any clear variation with redshift.


title: Weighted scale invariant quantum field theories

abstract:
  We study a class of Lorentz violating quantum field theories that contain
higher space derivatives, but no higher time derivatives, and become
renormalizable in the large N expansion. The fixed points of their
renormalization-group flows provide examples of exactly "weighted scale
invariant" theories, which are noticeable Lorentz violating generalizations of
conformal field theories. We classify the scalar and fermion models that are
causal, stable and unitary. Solutions exist also in four and higher dimensions,
even and odd. In some explicit four dimensional examples, we compute the
correlation functions to the leading order in 1/N and the critical exponents to
the subleading order. We construct also RG flows interpolating between pairs of
fixed points.


title: Optical Intra-day Variability in Blazars

abstract:
  We selected a sample of a dozen blazars which are the prime candidates for
simultaneous multi-wavelength observing campaigns in their outburst phase. We
searched for optical outbursts, intra-day variability and short term
variability in these blazars. We carried out optical photometric monitoring of
nine of these blazars in 13 observing nights during our observing run October
27, 2006 - March 20, 2007 by using the 1.02 meter optical telescope. From our
observations, our data favor the hypothesis that three blazars were in the
outburst state; one blazar was in the post outburst state; three blazars were
in the pre/post outburst state; one blazar was in the low-state; and the state
of one blazar was not known because there is not much optical data available
for the blazar to compare with our observations. Out of three nights of
observations of AO 0235+164, intra-day variability was detected in two nights.
Out of five nights of observations of S5 0716+714, intra-day variability was
detected in two nights. In one night of observations of PKS 0735+178, intra-day
variability was detected. Out of six nights of observations of 3C 454.3,
intra-day variability was detected in three nights. No intra-day variability
was detected in S2 0109+224, OJ 287, ON 231, 3C 279 and 1ES 2344+514 in their
1, 4, 1, 2 and 1 nights of observations respectively. AO 0235+164, S5 0716+714,
OJ 287, 3C 279 and 3C 454.3 were observed in more than one night and short term
variations in all these blazars were also noticed. From our observations and
the available data, we found that the predicted optical outburst with the time
interval of ~ 8 years in AO 0235+164 and ~ 3 years in S5 0716+714 have possibly
occurred.


title:
Scaling Relations for self-Similar Structures and the Cosmological
  Constant

abstract:
  Scaling relations for the mass, angular momentum and other properties of a
wide range of self-similar structures in the universe are seen to have
universal features. As a consequence of the ideas elaborated in earlier papers
these relations can be connected to a background constant curvature given by
the cosmological constant dominating cosmical dynamics.


title:
DSL development based on target meta-models. Using AST transformations
  for automating semantic analysis in a textual DSL framework

abstract:
  This paper describes an approach to creating textual syntax for Do-
main-Specific Languages (DSL). We consider target meta-model to be the main
artifact and hence to be developed first. The key idea is to represent analysis
of textual syntax as a sequence of transformations. This is made by explicit
opera- tions on abstract syntax trees (ATS), for which a simple language is
proposed. Text-to-model transformation is divided into two parts: text-to-AST
(developed by openArchitectureWare [1]) and AST-to-model (proposed by this
paper). Our approach simplifies semantic analysis and helps to generate as much
as possi- ble.


title:
Optimal co-adapted coupling for the symmetric random walk on the
  hypercube

abstract:
  Let X and Y be two simple symmetric continuous-time random walks on the
vertices of the n-dimensional hypercube. We consider the class of co-adapted
couplings of these processes, and describe an intuitive coupling which is shown
to be the fastest in this class.


title: On the singularity of random matrices with independent entries

abstract:
  We consider n by n real matrices whose entries are non-degenerate random
variables that are independent but non necessarily identically distributed, and
show that the probability that such a matrix is singular is O(1/sqrt{n}). The
purpose of this note is to provide a short and elementary proof of this fact
using a Bernoulli decomposition of arbitrary non degenerate random variables.


title:
Multigrid Hirsch-Fye quantum Monte Carlo method for dynamical mean-field
  theory

abstract:
  We present a new algorithm which allows for direct numerically exact
solutions within dynamical mean-field theory (DMFT). It is based on the
established Hirsch-Fye quantum Monte Carlo (HF-QMC) method. However, the DMFT
impurity model is solved not at fixed imaginary-time discretization Delta_tau,
but for a range of discretization grids; by extrapolation, unbiased Green
functions are obtained in each DMFT iteration. In contrast to conventional
HF-QMC, the multigrid algorithm converges to the exact DMFT fixed points. It
extends the useful range of Delta_tau, is precise and reliable even in the
immediate vicinity of phase transitions and is more efficient, also in
comparison to continuous-time methods. Using this algorithm, we show that the
spectral weight transfer at the Mott transition has been overestimated in a
recent density matrix renormalization group study.


title:
The c2d Spitzer spectroscopy survey of ices around low-mass young
  stellar objects, III: CH4

abstract:
  CH4 is proposed to be the starting point of a rich organic chemistry. Solid
CH4 abundances have previously been determined mostly toward high mass star
forming regions. Spitzer/IRS now provides a unique opportunity to probe solid
CH4 toward low mass star forming regions as well. Infrared spectra from the
Spitzer Space Telescope are presented to determine the solid CH4 abundance
toward a large sample of low mass young stellar objects. 25 out of 52 ice
sources in the $c2d$ (cores to disks) legacy have an absorption feature at 7.7
um, attributed to the bending mode of solid CH4. The solid CH4 / H2O abundances
are 2-8%, except for three sources with abundances as high as 11-13%. These
latter sources have relatively large uncertainties due to small total ice
column densities. Toward sources with H2O column densities above 2E18 cm-2, the
CH4 abundances (20 out of 25) are nearly constant at 4.7+/-1.6%. Correlation
plots with solid H2O, CH3OH, CO2 and CO column densities and abundances
relative to H2O reveal a closer relationship of solid CH4 with CO2 and H2O than
with solid CO and CH3OH. The inferred solid CH4 abundances are consistent with
models where CH4 is formed through sequential hydrogenation of C on grain
surfaces. Finally the equal or higher abundances toward low mass young stellar
objects compared with high mass objects and the correlation studies support
this formation pathway as well, but not the two competing theories: formation
from CH3OH and formation in gas phase with subsequent freeze-out.


title: Counting metastable states of Ising spin glasses on arbitrary graphs

abstract:
  Using a field-theoretical representation of the Tanaka-Edwards integral we
develop a method to systematically compute the number N_s of 1-spin-stable
states (local energy minima) of a glassy Ising system with nearest-neighbor
interactions and random Gaussian couplings on an arbitrary graph. In
particular, we use this method to determine N_s for K-regular random graphs and
d-dimensional regular lattices for d=2,3. The method works also for other
graphs. Excellent accuracy of the results allows us to observe that the number
of local energy minima depends mainly on local properties of the graph on which
the spin glass is defined.


title: Arakelov theory of noncommutative arithmetic surfaces

abstract:
  The purpose of this paper is to initiate Arakelov theory in a noncommutative
setting. More precisely, we are concerned with noncommutative arithmetic
surfaces. We introduce a version of arithmetic intersection theory on
noncommutative arithmetic surfaces and we prove an arithmetic Riemann-Roch
theorem in this setup.


title:
Character expansion method for supergroups and extended superversions of
  the Leutwyler-Smilga and Berezin-Karpelevich integrals

abstract:
  We introduce an extension of the character expansion method to the case of
supergroups. This method allows us to calculate a superversion of the
Leutwyler-Smilga integral which, to the best of our knowledge, has not been
calculated before. We also use the method to generalize a previously calculated
superversion of the Berezin-Karpelevich integral. Our character expansion
method should also allow for the calculation of other supergroup integrals.


title: The diffuse GeV-TeV $\gamma$-ray emission of the Cygnus region

abstract:
  Recently the Milagro experiment observed diffuse multi-TeV gamma-ray emission
in the Cygnus region, which is significantly stronger than what predicted by
the Galactic cosmic ray model. However, the sub-GeV observation by EGRET shows
no excess to the prediction based on the same model. This TeV excess implies
possible high energy cosmic rays populated in the region with harder spectrum
than that observed on the Earth. In the work we studied this theoretical
speculation in detail. We find that, a diffuse proton source with power index
$\alpha_p\lesssim 2.3$, or a diffuse electron source with power index
$\alpha_e\lesssim2.6$ can reproduce the Milagro's observation without
conflicting with the EGRET data. Further detections on neutrinos, a diagnostic
of the hadronic model, and hard X-ray synchrontron radiation, a diagnostic of
the lepton model, help to break this degeneracy. In combination with the gamma
ray observations to several hundred GeV by Fermi, we will be able to understand
the diffuse emission mechanisms in the Cygnus region better.


title: WELS - Ultraviolet Spectra and Expanding Atmosphere Models

abstract:
  The ultraviolet spectra of all "weak emission line central stars of planetary
nebulae" (WELS) with available IUE data is analyzed. We found that the WELS can
be divided in three different groups regarding their UV: (1) Strong P-Cygni
profiles (mainly in C IV 1549); (2) Weak P-Cygni features and (3) Absence of
P-Cygni profiles. We have measured wind terminal velocities for all objects
presenting P-Cygni profiles in N V 1238 and/or C IV 1549. The results obtained
were compared to the UV data of the two prototype stars of the [WC]-PG 1159
class, namely, A30 and A78. They indicate that WELS are distinct from the
[WC]-PG 1159 stars, in contrast to previous claims in the literature. In order
to gain a better understanding about the WELS, we clearly need to determine
their physical parameters and chemical abundances. First non LTE expanding
atmosphere models (using the CMFGEN code) for the UV and optical spectra of the
star Hen 2-12 are presented.


title:
An Izergin-Korepin-type identity for the 8VSOS model, with applications
  to alternating sign matrices

abstract:
  We obtain a new expression for the partition function of the 8VSOS model with
domain wall boundary conditions, which we consider to be the natural extension
of the Izergin-Korepin formula for the six-vertex model. As applications, we
find dynamical (in the sense of the dynamical Yang-Baxter equation)
generalizations of the enumeration and 2-enumeration of alternating sign
matrices. The dynamical enumeration has a nice interpretation in terms of
three-colourings of the square lattice.


title:
Classification of two dimensional split trianguline representations of
  $p$-adic fields

abstract:
  The aim of this paper is to classify two dimensional split trianguline
representations of $p$-adic fields. This is a generalization of a result of
Colmez who classified two dimensional split trianguline representations of
$\mathrm{Gal}(\bar{\mathbb{Q}}_p/\mathbb{Q}_p)$ by using
$(\phi,\Gamma)$-modules over Robba ring. In this paper, we classify two
dimensional split trianguline representations of $\mathrm{Gal}(\bar{K}/K)$ for
general $p$-adic field $K$ by using $B$-pairs defined by Berger.


title:
Optimizing the ionization and energy absorption of laser-irradiated
  clusters

abstract:
  It is known that rare-gas or metal clusters absorb incident laser energy very
efficiently. However, due to the intricate dependencies on all the laser and
cluster parameters it is difficult to predict under which circumstances
ionization and energy absorption is optimal.
  With the help of three-dimensional particle-in-cell simulations of xenon
clusters (up to 17256 atoms) we find that for a given laser pulse energy and
cluster an optimum wavelength exists which corresponds to the approximate
wavelength of the transient, linear Mie-resonance of the ionizing cluster at an
early stage of negligible expansion. In a single ultrashort laser pulse, the
linear resonance at this optimum wavelength yields much higher absorption
efficiency than in the conventional, dual-pulse pump-probe set-up of linear
resonance during cluster expansion.


title:
The Milky Way's Circular Velocity Curve to 60 kpc and an Estimate of the
  Dark Matter Halo Mass from Kinematics of ~2400 SDSS Blue Horizontal Branch
  Stars

abstract:
  We derive new constraints on the mass of the Milky Way's dark matter halo,
based on a set of halo stars from SDSS as kinematic tracers. Our sample
comprises 2401 rigorously selected Blue Horizontal-Branch (BHB) halo stars
drawn from SDSS DR-6. To interpret these distributions, we compare them to
matched mock observations drawn from two different cosmological galaxy
formation simulations designed to resemble the Milky Way, which we presume to
have an appropriate orbital distribution of halo stars. We then determine which
value of $\rm V_{cir}(r)$ brings the observed distribution into agreement with
the corresponding distributions from the simulations. This procedure results in
an estimate of the Milky Way's circular velocity curve to $\sim 60$ kpc, which
is found to be slightly falling from the adopted value of $\rm 220 km s^{-1}$
at the Sun's location, and implies M$(<60 \rm kpc) = 4.0\pm 0.7\times
10^{11}$M$_\odot$. The radial dependence of $\rm V_{cir}(r)$, derived in
statistically independent bins, is found to be consistent with the expectations
from an NFW dark matter halo with the established stellar mass components at
its center. If we assume an NFW halo profile of characteristic concentration
holds, we can use the observations to estimate the virial mass of the Milky
Way's dark matter halo, M$_{\rm vir}=1.0^{+0.3}_{-0.2} \times
10^{12}$M$_\odot$, which is lower than many previous estimates. This estimate
implies that nearly 40% of the baryons within the virial radius of the Milky
Way's dark matter halo reside in the stellar components of our Galaxy. A value
for M$_{\rm vir}$ of only $\sim 1\times10^{12}$M$_\odot$ also (re-)opens the
question of whether all of the Milky Way's satellite galaxies are on bound
orbits.


title: A Galois correspondence for compact quantum group actions

abstract:
  We establish a Galois correspondence for a minimal action of a compact
quantum group ${\mathbb G}$ on a von Neumann factor $M$. This extends the
result of Izumi, Longo and Popa who treated the case of a Kac algebra. Namely,
there exists a one-to-one correspondence between the lattice of left coideals
of ${\mathbb G}$ and that of intermediate subfactors of $M^{\mathbb G}\subset
M$.


title:
Bell's Theorem, Many Worlds and Backwards-Time Physics: Not Just a
  Matter of Interpretation

abstract:
  The classic "Bell's Theorem" of Clauser, Holt, Shimony and Horne tells us
that we must give up at least one of: (1) objective reality (aka "hidden
variables"); (2) locality; or (3) time-forwards macroscopic statistics (aka
"causality"). The orthodox Copenhagen version of physics gives up the first.
The many-worlds theory of Everett and Wheeler gives up the second. The
backwards-time theory of physics (BTP) gives up the third. Contrary to
conventional wisdom, empirical evidence strongly favors Everett-Wheeler over
orthodox Copenhagen. BTP has two major variations -- a many-worlds version, and
a neoclassical version of partial differential equations (PDE) in the spirit of
Einstein. Section 2 discusses quantum measurement according to BTP, focusing on
how we represent condensed matter objects like polarizers in a Bell's Theorem
experiment or in tests of Hawking's cosmology. The Backwards Time Telegraph,
though speculative, is discussed.


title:
Study of W boson polarisations and Triple Gauge boson Couplings in the
  reaction e+e- -> W+W- at LEP 2

abstract:
  A determination of the single W Spin Density Matrix (SDM) elements in the
reaction e+e- -> W+W- -> l nu q qbar (l=e/mu) is reported at centre-of-mass
energies between 189 and 209 GeV. The data sample used corresponds to an
integrated luminosity of 520 pb^{-1} taken by DELPHI between 1998 and 2000. The
single W SDM elements, rho_{tau tau'}^{W+-} (tau,tau' = +/-1 or 0), are
determined as a function of the W- production angle with respect to the e- beam
direction and are obtained from measurements of the W decay products by the
application of suitable projection operators, Lambda_{tau tau'}, which assume
the V-A coupling of the W boson to fermions. The measured SDM elements are used
to obtain the fraction of longitudinally polarised Ws, with the result:
sigma_L/sigma_tot = 24.9 +/- 4.5(stat) +/- 2.2(syst) % at a mean energy of 198
GeV. The SDM elements are also used to determine the Triple Gauge Couplings
Delta g_1^Z, Delta kappa_gamma, lambda_gamma and g_4^Z, kappa_Z and lambda_Z.
For the CP-violating couplings the results of single parameter fits are: g_4^Z
= -0.39 +0.19 -0.20 kappa_Z = -0.09 +0.08 -0.05 lambda_Z = -0.08 +/- 0.07 . The
errors are a combination of statistical and systematic errors. All results are
consistent with the Standard Model.


title:
Radio-to-UV monitoring of AO 0235+164 by the WEBT and Swift during the
  2006--2007 outburst

abstract:
  The blazar AO 0235+164 was claimed to show a quasi-periodic behaviour in the
radio and optical bands. Moreover, an extra emission component contributing to
the UV and soft X-ray flux was detected, whose nature is not yet clear. A
predicted optical outburst was observed in late 2006/early 2007. We here
present the radio-to-optical WEBT light curves during the outburst, together
with UV data acquired by Swift in the same period. We found the optical
outburst to be as strong as the big outbursts of the past: starting from late
September 2006, a brightness increase of 5 mag led to the outburst peak in
February 19-21, 2007. We also observed an outburst at mm and then at cm
wavelengths, with an increasing time delay going toward lower frequencies
during the rising phase. Cross-correlation analysis indicates that the 1 mm and
37 GHz flux variations lagged behind the R-band ones by about 3 weeks and 2
months, respectively. These short time delays suggest that the corresponding
jet emitting regions are only slightly separated and/or misaligned. In
contrast, during the outburst decreasing phase the flux faded contemporaneously
at all cm wavelengths. This abrupt change in the emission behaviour may suggest
the presence of some shutdown mechanism of intrinsic or geometric nature. The
behaviour of the UV flux closely follows the optical and near-IR one. By
separating the synchrotron and extra component contributions to the UV flux, we
found that they correlate, which suggests that the two emissions have a common
origin.


title:
Reconstruction of the transit signal in the presence of stellar
  variability

abstract:
  Intrinsic stellar variability can hinder the detection of shallow transits,
particularly in space-based data. Therefore, this variability has to be
filtered out before running the transit search. Unfortunately, filtering out
the low frequency signal of the stellar variability also modifies the transit
shape. This results in errors in the measured transit depth and duration used
to derive the planet radius, and orbital inclination. We present an evaluation
of the magnitude of this effect based on 20 simulated light curves from the
CoRoT blind exercise 2 (BT2). We then present an iterative filter which uses
the strictly periodic nature of the transits to separate them from other forms
of variability, so as to recover the original transit shape before deriving the
planet parameters. On average with this filter, we improve the estimation of
the transit depth and duration by 15% and 10% respectively.