title:
Pre-Merger Localization of Gravitational-Wave Standard Sirens With LISA:
  Triggered Search for an Electromagnetic Counterpart

abstract:
  Electromagnetic (EM) counterparts to supermassive black hole binary mergers
observed by LISA can be localized to within the field of view of astronomical
instruments ~10 deg^2 hours to weeks prior to coalescence. The temporal
coincidence of any prompt EM counterpart with a gravitationally-timed merger
may offer the best chance of identifying a unique host galaxy. We discuss the
challenges posed by searches for prompt EM counterparts and propose novel
observational strategies to address them. In particular, we discuss the size
and shape evolution of the LISA localization error ellipses on the sky, and
quantify the requirements for dedicated EM surveys of the area prior to
coalescence. A triggered EM counterpart search campaign will require monitoring
a several-square degree area. It could aim for variability at the 24-27 mag
level in optical bands, for example, which corresponds to 1-10% of the
Eddington luminosity of the prime LISA sources of 10^6-10^7 Msun BHs at z=1-2,
on time-scales of minutes to hours, the orbital time-scale of the binary in the
last 2-4 weeks. A cross-correlation of the period of any variable EM signal
with the quasi-periodic gravitational waveform over 10-1000 cycles may aid the
detection. Alternatively, EM searches can detect a transient signal
accompanying the coalescence. We highlight the measurement of differences in
the arrival times of photons and gravitons from the same cosmological source as
a valuable independent test of the massive character of gravity, and of
possible violations of Lorentz invariance in the gravity sector.


title: Probing a massive radio galaxy with gravitational lensing

abstract:
  The gravitational lens system CLASS B2108+213 has two lensed images separated
by 4.56 arcsec. Such a wide image separation suggests that the lens is either a
massive galaxy, or is composed of a group of galaxies. To investigate the
structure of the lensing potential we have carried out new high resolution
imaging of the two lensed images at 1.7 GHz with the VLBA and at 5 GHz with
global VLBI. Compact and extended emission is detected from the two lensed
images, which provides additional constraints to the lensing mass model. We
find that the data are consistent with either a single lensing galaxy, or a two
galaxy lens model that takes account of a nearby companion to the main lensing
galaxy within the Einstein radius of the system. However, for an ensemble of
global power-law mass models, those with density profiles steeper than
isothermal are a better fit. The best-fitting profile for a single spherical
mass model has a slope of $\gamma=$~2.45$_{-0.18}^{+0.19}$. The system also has
a third radio component which is coincident with the main lensing galaxy. This
component is detected at milli-arcsecond scales for the first time by the 1.7
GHz VLBA and 5 GHz global VLBI imaging. However, the third radio component is
found not to be consistent with a core lensed image because the radio spectrum
differs from the two lensed images, and its flux-density is too high when
compared to what is expected from simple mass models with a variable power-law
density profile and/or a reasonable core radius. Furthermore, 1.4 GHz imaging
of the system with the MERLIN finds extended lobe emission on either side of
the main lensing galaxy. Therefore, the radio emission from the third radio
component is almost certainly from an AGN within the main lensing galaxy, which
is classified as an FR I type radio source.


title: Evolution of cosmic superstring networks: a numerical simulation

abstract:
  We study the formation and evolution of an interconnected string network in
large-scale field-theory numerical simulations, both in flat spacetime and in
expanding universe. The network consists of gauge U(1) strings of two different
kinds and their bound states, arising due to an attractive interaction
potential. We find that the network shows no tendency to ``freeze'' and appears
to approach a scaling regime, with all characteristic lengths growing linearly
with time. Bound strings constitute only a small fraction of the total string
length in the network.


title:
Upper limit on the cosmic-ray photon flux above 10^19 eV using the
  surface detector of the Pierre Auger Observatory

abstract:
  A method is developed to search for air showers initiated by photons using
data recorded by the surface detector of the Auger Observatory. The approach is
based on observables sensitive to the longitudinal shower development, the
signal risetime and the curvature of the shower front. Applying this method to
the data, upper limits on the flux of photons of 3.8*10^-3, 2.5*10^-3, and
2.2*10^-3 km^-2 sr^-1 yr^-1 above 10^19 eV, 2*10^19 eV, and 4*10^19 eV are
derived, with corresponding limits on the fraction of photons being 2.0%, 5.1%,
and 31% (all limits at 95% c.l.). These photon limits disfavor certain exotic
models of sources of cosmic rays. The results also show that the approach
adopted by the Auger Observatory to calibrate the shower energy is not strongly
biased by a contamination from photons.


title:
Detection of primordial non-Gaussianity (fNL) in the WMAP 3-year data at
  above 99.5% confidence

abstract:
  We present evidence for the detection of primordial non-Gaussianity of the
local type (fNL), using the temperature information of the Cosmic Microwave
Background (CMB) from the WMAP 3-year data. We employ the bispectrum estimator
of non-Gaussianity described in (Yadav et al. 2007) which allows us to analyze
the entirety of the WMAP data without an arbitrary cut-off in angular scale.
Using the combined information from WMAP's two main science channels up to
lmax=750 and the conservative Kp0 foreground mask we find 27 < fNL < 147 at 95%
C.L., with a central value of fNL=87. This corresponds to a rejection of fNL=0
at more than 99.5% significance. We find that this detection is robust to
variations in lmax, frequency and masks, and that no known foreground,
instrument systematic, or secondary anisotropy explains our signal while
passing our suite of tests. We explore the impact of several analysis choices
on the stated significance and find 2.5 sigma for the most conservative view.
We conclude that the WMAP 3-year data disfavors canonical single field
slow-roll inflation.


title: Midplane Gas Density and the Schmidt Law

abstract:
  The thickness of isothermal gaseous layers and their midplane volume
densities \rho_{gas}(R) were calculated for several spiral and LSB galaxies by
solving the self-consistent equilibrium equations for gaseous discs embedded
into a stellar one. The self-gravity of the gas and influence of dark halo on
the disk thickness were taken into account. The resulting midplane volume
densities of spiral galaxies were compared with the azimuthally averaged star
formation rate SFR to verify the feasibility and universality of the Schmidt
law SFR ~ \rho_{gas}^n.


title: The nature of the ghost cavity in the NGC 741 group

abstract:
  We discuss the effects of energy injection into the intra-group medium of the
group of galaxies associated with NGC 741. The X-ray emission reveals a large
bubble, which in the absence of a currently bright central radio source, may
have been inflated by a previous cycle of nuclear activity . If the bubble is
filled with a light, relativistic fluid we calculate that in expanding, it has
done more than sufficient work to counteract the energy lost from the
intra-group medium via radiative cooling; the bubble can provide this energy as
it expands and rises. Using upper limits on the flux density of the plasma
filling the bubble at 330 MHz and 1.4 GHz, we derive constraints on its
electron energy distribution and magnetic field strength. We show that the data
require the high-energy cut-off of the electron spectrum to be very low
compared to the cut-offs seen in more typical radio sources if the fluid
filling the bubble is a conventional relativistic plasma. This suggests that
the fluid filling the bubble may not have evolved by expansion or synchrotron
losses consistent with a dead radio source, leaving a puzzle as to what the
origin of the bubble may be.


title: Effect of the Coulomb interaction in A(d,p) fragmentation

abstract:
  In the framework of Glauber-Sitenko model we calculate contribution of
Coulomb interaction in cross-section of A(d,p) reaction at high energy and zero
angle. It is demonstrated that such effect significantly increases the
differential cross section only at peak, where the proton momentum $p$ is near
half of the deuteron momentum $p_d$ in lab. frame, $p \sim \frac12 p_d$. The
Coulomb interaction do not change the results in the high momentum region,
where quark effects should be taken into account.


title:
Euler equation for incompressible non-Newtonian fluids: finite speed of
  propagations and asymptotic behavior of weak solutions

abstract:
  We investigate multidimensional model for incompressible non-Newtonian
fluids. Using method of energy estimates we prove the property of finite speed
of propagations of the solution support for this problem. We find sharp bounds
of the propagations by $L^2$--norm and $L^1$--norm of initial data.


title: Superfluidity of $^4$He Confined in Nano-Porous Media

abstract:
  We have examined superfluid properties of $^4$He confined to a nano-porous
Gelsil glass that has nanopores 2.5 nm in diameter. The pressure-temperature
phase diagram was determined by torsional oscillator, heat capacity and
pressure studies. The superfluid transition temperature $T_{\mathrm c}$
approaches zero at 3.4 MPa, indicating a novel "quantum" superfluid transition.
By heat capacity measurements, the nonsuperfluid phase adjacent to the
superfluid and solid phases is identified to be a nanometer-scale, localized
Bose condensation state, in which global phase coherence is destroyed. At high
pressures, the superfluid density has a $T$-linear term, and $T_{\mathrm c}$ is
proportional to the zero-temperature superfluid density. These results strongly
suggest that phase fluctuations in the superfluid order parameter play a
dominant role on the phase diagram and superfluid properties.


title: Many-Body Physics and Quantum Chaos

abstract:
  Experimental progresses in the miniaturisation of electronic devices have
made routinely available in the laboratory small electronic systems, on the
micron or sub-micron scale, which at low temperature are sufficiently well
isolated from their environment to be considered as fully coherent. Some of
their most important properties are dominated by the interaction between
electrons. Understanding their behaviour therefore requires a description of
the interplay between interference effects and interactions.
  The goal of this review is to address this relatively broad issue, and more
specifically to address it from the perspective of the quantum chaos community.
I will therefore present some of the concepts developed in the field of quantum
chaos which have some application to study many-body effects in mesoscopic and
nanoscopic systems. Their implementation is illustrated on a few examples of
experimental relevance such as persistent currents, mesoscopic fluctuations of
Kondo properties or Coulomb blockade. I will furthermore try to bring out, from
the various physical illustrations, some of the specific advantages on more
general grounds of the quantum chaos based approach.


title:
The colour-lightcurve shape relation of Type Ia supernovae and the
  reddening law

abstract:
  A study of the time sequence of optical colours of a large sample of nearby
Type Ia supernovae (SNe Ia) is presented. We study the dependence of the colour
time evolution with respect to the lightcurve shape, parametrized by the
stretch factor. We fit the spectral template that minimizes the colour
dispersion in SNe Ia, as measured through UBVRI photometry of near-by
supernovae. A clear colour dependence upon lightcurve shape is found, with the
narrower lightcurves being redder up to about one month past lightcurve
maximum. We also derive an average reddening law, after correcting for
lightcurve shape differences in intrinsic colour, that is well described by a
Cardelli, Clayton & Mathis law with R_V=1.75 \pm 0.27 for 80 Type Ia supernovae
with E(B-V) < 0.7 mag. A subset sample including 69 SNe with modest reddening,
E(B-V)<0.25 mag, yields a significantly smaller value, R_V ~ 1, suggesting that
the observed reddening of Type Ia supernovae may have a more complex origin,
perhaps involving other processes beside extinction by interstellar dust in the
host galaxy.


title:
Tidal friction in close-in satellites and exoplanets. The Darwin theory
  re-visited

abstract:
  This report is a review of Darwin's classical theory of bodily tides in which
we present the analytical expressions for the orbital and rotational evolution
of the bodies and for the energy dissipation rates due to their tidal
interaction. General formulas are given which do not depend on any assumption
linking the tidal lags to the frequencies of the corresponding tidal waves
(except that equal frequency harmonics are assumed to span equal lags).
Emphasis is given to the cases of companions having reached one of the two
possible final states: (1) the super-synchronous stationary rotation resulting
from the vanishing of the average tidal torque; (2) the capture into a 1:1
spin-orbit resonance (true synchronization). In these cases, the energy
dissipation is controlled by the tidal harmonic with period equal to the
orbital period (instead of the semi-diurnal tide) and the singularity due to
the vanishing of the geometric phase lag does not exist. It is also shown that
the true synchronization with non-zero eccentricity is only possible if an
extra torque exists opposite to the tidal torque. The theory is developed
assuming that this additional torque is produced by an equatorial permanent
asymmetry in the companion. The results are model-dependent and the theory is
developed only to the second degree in eccentricity and inclination
(obliquity). It can easily be extended to higher orders, but formal accuracy
will not be a real improvement as long as the physics of the processes leading
to tidal lags is not better known.


title:
Detecting changes in the fluctuations of a Gaussian process and an
  application to heartbeat time series

abstract:
  The aim of this paper is first the detection of multiple abrupt changes of
the long-range dependence (respectively self-similarity, local fractality)
parameters from a sample of a Gaussian stationary times series (respectively
time series, continuous-time process having stationary increments). The
estimator of the $m$ change instants (the number $m$ is supposed to be known)
is proved to satisfied a limit theorem with an explicit convergence rate.
Moreover, a central limit theorem is established for an estimator of each
long-range dependence (respectively self-similarity, local fractality)
parameter. Finally, a goodness-of-fit test is also built in each time domain
without change and proved to asymptotically follow a Khi-square distribution.
Such statistics are applied to heart rate data of marathon's runners and lead
to interesting conclusions.


title:
Numerical test of the theory of pseudo-diffusive transmission at the
  Dirac point of a photonic band structure

abstract:
  It has recently been predicted that a conical singularity (= Dirac point) in
the band structure of a photonic crystal produces an unusual 1/L scaling of the
photon flux transmitted through a slab of thickness L. This inverse-linear
scaling is unusual, because it is characteristic of radiative transport via
diffusion modes through a disordered medium -- while here it appears for
propagation of Bloch modes in an ideal crystal without any disorder. We present
a quantitative numerical test of the predicted scaling, by calculating the
scattering of transverse-electric (TE) modes by a two-dimensional triangular
lattice of dielectric rods in air. We verify the 1/L scaling and show that the
slope differs by less than 10% from the value predicted for maximal coupling of
the Bloch modes in the photonic crystal to the plane waves in free space.


title: CRASH_alpha: coupling continuum and line radiative transfer

abstract:
  In this paper we present CRASH_alpha, the first radiative transfer code for
cosmological application that follows the parallel propagation of Ly_alpha and
ionizing photons. CRASH_alpha is a version of the continuum radiative transfer
code CRASH with a new algorithm to follow the propagation of Ly_alpha photons
through a gas configuration whose ionization structure is evolving. The
implementation introduces the time evolution for Ly_alpha photons (a feature
commonly neglected in line radiative transfer codes) and, to reduce the
computational time needed to follow each scattering, adopts a statistical
approach to the Ly_alpha treatment by making extensive use of pre-compiled
tables. With this statistical approach we experience a drastic increase of the
computational speed and, at the same time, an excellent agreement with the full
Ly_alpha radiative transfer computations of the code MCLy_alpha. We find that
the emerging spectra keep memory of the ionization history which generates a
given ionization configuration of the gas and, to properly account for this
effect, a self-consistent joint evolution of line and ionizing continuum
radiation as implemented in CRASH_alpha is necessary. A comparison between the
results from our code and from Ly_alpha scattering alone on a fixed HI density
field shows that the extent of the difference between the emerging spectra
depends on the particular configuration considered, but it can be substantial
and can thus affect the physical interpretation of the problem at hand. These
differences should furthermore be taken into account when computing the impact
of the Ly_alpha radiation on e.g. the observability of the 21 cm line from
neutral hydrogen at epochs preceeding complete reionization.


title:
An Explosive End to Intermediate-Mass Zero-Metallicity Stars and Early
  Universe Nucleosynthesis

abstract:
  We use the Cambridge stellar evolution code STARS to model the evolution of
5-7 solar mass zero-metallicity stars. With enhanced resolution at the hydrogen
and helium burning shell in the AGB phases, we are able to model the entire
thermally pulsing asymptotic giant branch (TP-AGB) phase. The helium
luminosities of the thermal pulses are significantly lower than in higher
metallicity stars so there is no third dredge-up. The envelope is enriched in
nitrogen by hot-bottom burning of carbon that was previously mixed in during
second dredge-up. There is no s-process enrichment owing to the lack of third
dredge up. The thermal pulses grow weaker as the core mass increases and they
eventually cease. From then on the star enters a quiescent burning phase which
lasts until carbon ignites at the centre of the star when the CO core mass is
1.36 solar mass. With such a high degeneracy and a core mass so close to the
Chandrasekhar mass, we expect these stars to explode as type 1.5 supernovae,
very similar to Type Ia supernovae but inside a hydrogen rich envelope.


title: Spin effects in elastic backward P-D scattering

abstract:
  The elastic backward proton-deuteron scattering is analyzed including both
relativistic effects in the deuteron and the reaction mechanism. It is shown
that inclusion of the graphs corresponding to the emission, rescattering and
absorption of the virtual pion by a deuteron nucleon in addition to the
one-nucleon exchange graph allows a rather satisfactory description of all the
experimental data on the differential cross section, tensor analyzing power of
the deuteron and transfer polarization in this reaction.


title: The Evolution of Bias - Generalized

abstract:
  Fry (1996) showed that galaxy bias has the tendency to evolve towards unity,
i.e. in the long run, the galaxy distribution tends to trace that of matter.
Generalizing slightly Fry's reasoning, we show that his conclusion remains
valid in theories of modified gravity (or equivalently, complex clustered dark
energy). This is not surprising: as long as both galaxies and matter are
subject to the same force, dynamics would drive them towards tracing each
other. This holds, for instance, in theories where both galaxies and matter
move on geodesics. This relaxation of bias towards unity is tempered by cosmic
acceleration, however: the bias tends towards unity but does not quite make it,
unless the formation bias were close to unity. Our argument is extended in a
straightforward manner to the case of a stochastic or nonlinear bias. An
important corollary is that dynamical evolution could imprint a scale
dependence on the large scale galaxy bias. This is especially pronounced if
non-standard gravity introduces new scales to the problem: the bias at
different scales relaxes at different rates, the larger scales generally more
slowly and retaining a longer memory of the initial bias. A consistency test of
the current (general relativity + uniform dark energy) paradigm is therefore to
look for departure from a scale independent bias on large scales. A simple way
is to measure the relative bias of different populations of galaxies which are
at different stages of bias relaxation. Lastly, we comment on the possibility
of directly testing the Poisson equation on cosmological scales, as opposed to
indirectly through the growth factor.


title:
Efficient modularity optimization by multistep greedy algorithm and
  vertex mover refinement

abstract:
  Identifying strongly connected substructures in large networks provides
insight into their coarse-grained organization. Several approaches based on the
optimization of a quality function, e.g., the modularity, have been proposed.
We present here a multistep extension of the greedy algorithm (MSG) that allows
the merging of more than one pair of communities at each iteration step. The
essential idea is to prevent the premature condensation into few large
communities. Upon convergence of the MSG a simple refinement procedure called
"vertex mover" (VM) is used for reassigning vertices to neighboring communities
to improve the final modularity value. With an appropriate choice of the step
width, the combined MSG-VM algorithm is able to find solutions of higher
modularity than those reported previously. The multistep extension does not
alter the scaling of computational cost of the greedy algorithm.

categories: cs.DS cond-mat.dis-nn cs.DM physics.soc-ph


title: Spectrum of the non-abelian phase in Kitaev's honeycomb lattice model

abstract:
  The spectral properties of Kitaev's honeycomb lattice model are investigated
both analytically and numerically with the focus on the non-abelian phase of
the model. After summarizing the fermionization technique which maps spins into
free Majorana fermions, we evaluate the spectrum of sparse vortex
configurations and derive the interaction between two vortices as a function of
their separation. We consider the effect vortices can have on the fermionic
spectrum as well as on the phase transition between the abelian and non-abelian
phases. We explicitly demonstrate the $2^n$-fold ground state degeneracy in the
presence of $2n$ well separated vortices and the lifting of the degeneracy due
to their short-range interactions. The calculations are performed on an
infinite lattice. In addition to the analytic treatment, a numerical study of
finite size systems is performed which is in exact agreement with the
theoretical considerations. The general spectral properties of the non-abelian
phase are considered for various finite toroidal systems.


title:
Unsupervised and semi-supervised clustering by message passing:
  Soft-constraint affinity propagation

abstract:
  Soft-constraint affinity propagation (SCAP) is a new statistical-physics
based clustering technique. First we give the derivation of a simplified
version of the algorithm and discuss possibilities of time- and
memory-efficient implementations. Later we give a detailed analysis of the
performance of SCAP on artificial data, showing that the algorithm efficiently
unveils clustered and hierarchical data structures. We generalize the algorithm
to the problem of semi-supervised clustering, where data are already partially
labeled, and clustering assigns labels to previously unlabeled points. SCAP
uses both the geometrical organization of the data and the available labels
assigned to few points in a computationally efficient way, as is shown on
artificial and biological benchmark data.


title:
Linear optical response of current-carrying molecular junction: A
  NEGF-TDDFT approach

abstract:
  We propose a scheme for calculation of linear optical response of
current-carrying molecular junctions for the case when electronic tunneling
through the junction is much faster than characteristic time of external laser
field. We discuss relationships between nonequilibrium Green function (NEGF)
and time-dependent density functional theory (TDDFT) approaches, and derive
expressions for optical response and linear polarizability within NEGF-TDDFT
scheme. Corresponding results for isolated molecule, derived within TDDFT
approach previously, are reproduced when coupling to contacts is neglected.


title:
Transactional WaveCache: Towards Speculative and Out-of-Order DataFlow
  Execution of Memory Operations

abstract:
  The WaveScalar is the first DataFlow Architecture that can efficiently
provide the sequential memory semantics required by imperative languages. This
work presents an alternative memory ordering mechanism for this architecture,
the Transaction WaveCache. Our mechanism maintains the execution order of
memory operations within blocks of code, called Waves, but adds the ability to
speculatively execute, out-of-order, operations from different waves. This
ordering mechanism is inspired by progress in supporting Transactional
Memories. Waves are considered as atomic regions and executed as nested
transactions. If a wave has finished the execution of all its memory
operations, as soon as the previous waves are committed, it can be committed.
If a hazard is detected in a speculative Wave, all the following Waves
(children) are aborted and re-executed. We evaluate the WaveCache on a set
artificial benchmarks. If the benchmark does not access memory often, we could
achieve speedups of around 90%. Speedups of 33.1% and 24% were observed on more
memory intensive applications, and slowdowns up to 16% arise if memory
bandwidth is a bottleneck. For an application full of WAW, WAR and RAW hazards,
a speedup of 139.7% was verified.


title:
Properties of baryonic, electric and strangeness chemical potentials and
  some of their consequences in relativistic heavy ion collisions

abstract:
  Analytic expressions are given for the baryonic, electric and strangeness
chemical potentials which explicitly show the importance of various terms.
Simple scaling relations connecting these chemical potentials are found.
Applications to particle ratios and to fluctuations and related thermal
properties such as the isothermal compressibility kappaT are illustrated. A
possible divergence of kappaT is discussed.


title: Opportunistic Relaying in Wireless Networks

abstract:
  Relay networks having $n$ source-to-destination pairs and $m$ half-duplex
relays, all operating in the same frequency band in the presence of block
fading, are analyzed. This setup has attracted significant attention and
several relaying protocols have been reported in the literature. However, most
of the proposed solutions require either centrally coordinated scheduling or
detailed channel state information (CSI) at the transmitter side. Here, an
opportunistic relaying scheme is proposed, which alleviates these limitations.
The scheme entails a two-hop communication protocol, in which sources
communicate with destinations only through half-duplex relays. The key idea is
to schedule at each hop only a subset of nodes that can benefit from
\emph{multiuser diversity}. To select the source and destination nodes for each
hop, it requires only CSI at receivers (relays for the first hop, and
destination nodes for the second hop) and an integer-value CSI feedback to the
transmitters. For the case when $n$ is large and $m$ is fixed, it is shown that
the proposed scheme achieves a system throughput of $m/2$ bits/s/Hz. In
contrast, the information-theoretic upper bound of $(m/2)\log \log n$ bits/s/Hz
is achievable only with more demanding CSI assumptions and cooperation between
the relays. Furthermore, it is shown that, under the condition that the product
of block duration and system bandwidth scales faster than $\log n$, the
achievable throughput of the proposed scheme scales as $\Theta ({\log n})$.
Notably, this is proven to be the optimal throughput scaling even if
centralized scheduling is allowed, thus proving the optimality of the proposed
scheme in the scaling law sense.


title:
A preliminary study of asymmetric vocal fold vibrations: modeling and
  "in-vitro" validation

abstract:
  This paper deals with some of aspects of the influence of asymmetry on vocal
folds vibrations. A theoretical model of vocal fold asymmetry is presented. The
influence of asymmetry is quantitatively examined in terms of oscillation
frequency and pressure threshold. The theoretical model is compared to
"in-vitro" experiment on a deformable replica of vocal folds. It is found that
asymmetry strongly influences the oscillation subglottal pressure threshold.
Moreover, the vocal fold with the highest mechanical resonance frequency
imposes the oscillation fundamental frequency. The influence of geometrical
asymmetry instead of purely mechanical asymmetry is shown


abstract:
  These notes have been written to complete a mini-course "Introduction to
(generalized) Gibbs measures" given at the universities UFMG (Universidade
Federal de Minas Gerais, Belo Horizonte, Brasil) and UFRGS (Universidade
Federal do Rio Grande do Sul, Porto Alegre, Brasil) during the first semester
2007. The main goal of the lectures was to describe Gibbs and generalized Gibbs
measures on lattices at a rigorous mathematical level, as equilibirum states of
systems of a huge number of particles in interaction. In particular, our main
message is that although the historical approach based on potentials has been
rather successful from a physical point of view, one has to insist on (almost
sure) continuity properties of conditional probabilities to get a proper
mathematical framework.


title:
Iterative schemes for computing fixed points of nonexpansive mappings in
  Banach spaces

abstract:
  Let $X$ be a real Banach space with a normalized duality mapping uniformly
norm-to-weak$^\star$ continuous on bounded sets or a reflexive Banach space
which admits a weakly continuous duality mapping $J_{\Phi}$ with gauge $\phi$.
Let $f$ be an {\em $\alpha$-contraction} and $\{T_n\}$ a sequence of
nonexpansive mapping, we study the strong convergence of explicit iterative
schemes
  x_{n+1} = \alpha_n f(x_n) + (1-\alpha_n) T_n x_n
  with a general theorem and then recover and improve some specific cases
studied in the literature


title: HESS VHE Gamma-Ray Sources Without Identified Counterparts

abstract:
  The detection of gamma rays in the very-high-energy (VHE) energy range (100
GeV--100 TeV) provides a direct view of the parent population of
ultra-relativistic particles found in astrophysical sources. For this reason,
VHE gamma rays are useful for understanding the underlying astrophysical
processes in non-thermal sources. We investigate unidentified VHE gamma-ray
sources that have been discovered with HESS in the most sensitive blind survey
of the Galactic plane at VHE energies conducted so far. The HESS array of
imaging atmospheric Cherenkov telescopes (IACTs) has a high sensitivity
compared with previous instruments(~ 0.01 Crab) in 25 hours observation time
for a 5 sigma point-source detection), and with its large field of view, is
well suited for scan-based observations. The on-going HESS survey of the inner
Galaxy has revealed a large number of new VHE sources, and for each we attempt
to associate the VHE emission with multi-wavelength data in the radio through
X-ray wavebands. For each of the eight unidentified VHE sources considered
here, we present the energy spectra and sky maps of the sources and their
environment. The VHE morphology is compared with available multi-wavelength
data (mainly radio and X-rays). No plausible counterparts are found.


title: Search for anions in molecular sources: C4H- detection in L1527

abstract:
  We present the results of a search for the negative ion C4H- in various dark
clouds, low mass star-forming regions and photon-dominated regions (PDRs). We
have also searched for C6H-, C2H- and CN- in some of the sources. The
millimeter-wave observations were carried out with the IRAM-30m telescope. We
detect C4H-, through the J = 9-8 and J = 10-9 rotational transitions, in the
low mass star-forming region L1527. We thus confirm the tentative detection of
the J = 9-8 line recently reported toward this source. The [C4H-]/[C4H] ratio
found is 0.011 %, which is slightly lower than the value observed in IRC
+10216, 0.024 %, but above the 3 sigma upper limit we derive in TMC-1, < 0.0052
%. We have also derived an upper limit for the [C6H-]/[C6H] ratio in the
Horsehead Nebula, and for various anion-to-neutral ratios in the observed
sources. These results are compared with recent chemical models.


title:
Measurement of the Absolute Branching Fraction of D_s^+ --> tau^+ nu_tau
  Decay

abstract:
  Using a sample of tagged D_s decays collected near the D^*_s D_s peak
production energy in e+e- collisions with the CLEO-c detector, we study the
leptonic decay D^+_s to tau^+ nu_tau via the decay channel tau^+ to e^+ nu_e
bar{nu}_tau. We measure B(D^+_s to tau^+ nu_tau) = (6.17 +- 0.71 +- 0.34) %,
where the first error is statistical and the second systematic. Combining this
result with our measurements of D^+_s to mu^+ nu_mu and D^+_s to tau^+ nu_tau
(via tau^+ to pi^+ bar{nu}_tau), we determine f_{D_s} = (274 +- 10 +- 5) MeV.


title: Compactified Jacobians of curves with spine decompositions

abstract:
  A curve, that is, a connected, reduced, projective scheme of dimension 1 over
an algebraically closed field, admits two types of compactifications of its
(generalized) Jacobian: the moduli schemes of P-quasistable torsion-free,
rank-1 sheaves and Seshadri's moduli schemes of S-equivalence classes of
semistable torsion-free, rank-1 sheaves. Both are constructed with respect to a
choice of polarization. The former are fine moduli spaces which were shown to
be complete; here we show that they are actually projective. The latter are
just coarse moduli spaces. Here we give a sufficient condition for when these
two types of moduli spaces are equal.


title: Statefinder parameters in two dark energy models

abstract:
  The statefinder parameters ($r,s$) in two dark energy models are studied. In
the first, we discuss in four-dimensional General Relativity a two fluid model,
in which dark energy and dark matter are allowed to interact with each other.
In the second model, we consider the DGP brane model generalized by taking a
possible energy exchange between the brane and the bulk into account. We
determine the values of the statefinder parameters that correspond to the
unique attractor of the system at hand. Furthermore, we produce plots in which
we show $s,r$ as functions of red-shift, and the ($s-r$) plane for each model.


title: Test of CZT Detectors with Different Pixel Pitches and Thicknesses

abstract:
  The Modified Horizontal Bridgman (MHB) process produces Cadmium Zinc
Telluride (CZT) crystals with high yield and excellent homogeneity. Various
groups,including our own, previously reported on the test of 2x2x0.5 cm3 MHB
CZT detectors grown by the company Orbotech and read out with 8x8 pixels. In
this contribution, we describe the optimization of the photolithographic
process used for contacting the CZT detector with pixel contacts. The optimized
process gives a high yield of good pixels down to pixel diameters/pitches of 50
microns. Furthermore, we discuss the performance of 0.5 cm and 0.75 cm thick
detectors contacted with 64 and 225 pixel read out with the RENA-3 ASICs from
the company NOVA R&D.


title:
Life on the fast lane: the burst mode at the VLT at present and in the
  future

abstract:
  The recent implementation of the high-speed burst mode at the ISAAC
instrument on UT1, and its propagation to other ESO instruments, has opened the
door to observational capabilities which hold the potential for a wealth of
novel results. In the ELT era, when the accent will likely be on lengthy
programs aimed at the best sensitivity and angular resolution, the VLT
telescopes could continue to play a significant and largely unique role by
performing routinely observations of transient events at high temporal
resolution. In our contribution, we provide details on two such kinds of
observations, namely lunar occultations of stars and of asteroids. For the
first ones, we report on two passages of the Moon in regions with high stellar
density as the Galactic Center. The VLT-UT1 telescope was used for the first
time to record successfully 53 and 71 occultations on March 22 and August 6,
2006, with an angular resolution of 0.5-1 milliarcsecond and $K\sim12.5$
limiting magnitude. We note that the angular resolution is superior to that
achieved at present by Adaptive Optics on any telescope, and also superior to
that foreseen for the ELT at the same wavelength. LO are also very efficient in
terms of telescope time. We present some of the results, including the
discovery of close binaries, and the detection and study of compact
circumstellar components of cool giants, AGB stars and embedded IR sources.
  Rest of the abstract follows at the paper


title: Part I. The Cosmological Vacuum from a Topological Perspective

abstract:
  This article examines how the physical presence of field energy and
particulate matter can be interpreted in terms of the topological properties of
space-time. The theory is developed in terms of vector and matrix equations of
exterior differential systems, which are not constrained by tensor
diffeomorphic equivalences. The first postulate defines the field properties (a
vector space continuum) of the Cosmological Vacuum in terms of matrices of
basis functions that map exact differentials into neighborhoods of exterior
differential 1-forms (potentials). The second postulate requires that the field
equations must satisfy the First Law of Thermodynamics dynamically created in
terms of the Lie differential with respect to a process direction field acting
on the exterior differential forms that encode the thermodynamic system. The
vector space of infinitesimals need not be global and its compliment is used to
define particle properties as topological defects embedded in the field vector
space. The potentials, as exterior differential 1-forms, are not (necessarily)
uniquely integrable: the fibers can be twisted, leading to possible Chiral
matrix arrays of certain 3-forms defined as Topological Torsion and Topological
Spin. A significant result demonstrates how the coefficients of Affine Torsion
are related to the concept of Field excitations (mass and charge); another
demonstrates how thermodynamic evolution can describe the emergence of
topological defects in the physical vacuum.


title:
Searches for Multibaryon States with $\Lambda$ Hyperon Systems in pa
  Collision at 10 Gev/c

abstract:
  Experimental data as a stereo photographs from the 2m propane bubble chamber
LHE, JINR have been analyzed for exotic multibaryon metastable and stable
states searches. A number of peculiarities were found in the effective mass
spectra of: 1)$\Lambda \pi^{\pm}$,$\Lambda \pi^+ \pi^-$, $\Lambda p$, $\Lambda
p p$, $\Lambda \pi p$,$\Lambda \Lambda $ and $\Lambda K^0_S$ subsystems. The
observed well known $\Sigma^{*+}$(1385),$\Lambda ^*(1600)$ and
$K^{*\pm}$(892)resonances are good tests for this method. The width of
$\Sigma^{*-}(1385)$ for p+A reaction is two time larger than that presented in
PDG. The $\Lambda \pi^-$ spectrum observed enhancement in mass range of 1345
MeV/$c^2$ which interpreted as a stopped in nucleus $\Xi^-$. The cross section
of stopped $\Xi^-$ production is $\approx$ 8 times larger than obtained by
fritiof model with same experimental conditions.


title: Cumulative and Averaging Fission of Beliefs

abstract:
  Belief fusion is the principle of combining separate beliefs or bodies of
evidence originating from different sources. Depending on the situation to be
modelled, different belief fusion methods can be applied. Cumulative and
averaging belief fusion is defined for fusing opinions in subjective logic, and
for fusing belief functions in general. The principle of fission is the
opposite of fusion, namely to eliminate the contribution of a specific belief
from an already fused belief, with the purpose of deriving the remaining
belief. This paper describes fission of cumulative belief as well as fission of
averaging belief in subjective logic. These operators can for example be
applied to belief revision in Bayesian belief networks, where the belief
contribution of a given evidence source can be determined as a function of a
given fused belief and its other contributing beliefs.


title:
Opers with irregular singularity and spectra of the shift of argument
  subalgebra

abstract:
  The universal enveloping algebra of any simple Lie algebra g contains a
family of commutative subalgebras, called the quantum shift of argument
subalgebras math.RT/0606380, math.QA/0612798. We prove that generically their
action on finite-dimensional modules is diagonalizable and their joint spectra
are in bijection with the set of monodromy-free opers for the Langlands dual
group of G on the projective line with regular singularity at one point and
irregular singularity of order two at another point. We also prove a
multi-point generalization of this result, describing the spectra of commuting
Hamiltonians in Gaudin models with irregular singulairity. In addition, we show
that the quantum shift of argument subalgebra corresponding to a regular
nilpotent element of g has a cyclic vector in any irreducible
finite-dimensional g-module. As a byproduct, we obtain the structure of a
Gorenstein ring on any such module. This fact may have geometric significance
related to the intersection cohomology of Schubert varieties in the affine
Grassmannian.


title: Anomalous HI Gas in NGC 4395: Signs of Gas Accretion

abstract:
  In recent years, it has become clear that large quantities of gas reside in
the halos of many spiral galaxies. Whether the presence of this gas is
ultimately a consequence of star formation activity in the disk, or accretion
from outside of the galaxy, is not yet understood. We present new, deep HI
observations of NGC 4395 as part of a continuing observational program to
investigate this issue. We have detected a number of gas clouds with masses and
sizes similar to Milky Way HVCs. Some of these are in regions without currently
ongoing star formation, possibly indicating ongoing gas accretion.


title:
SpectroWeb: Oscillator Strength Measurements of Atomic Absorption Lines
  in the Sun and Procyon

abstract:
  We update the online SpectroWeb database of spectral standard reference stars
with 1178 oscillator strength values of atomic absorption lines observed in the
optical spectrum of the Sun and Procyon (Alpha CMi A). The updated line
oscillator strengths are measured with best fits to the disk-integrated
KPNO-FTS spectrum of the Sun observed between 4000 A and 6800 A using
state-of-the-art detailed spectral synthesis calculations. A subset of 660 line
oscillator strengths is validated with synthetic spectrum calculations of
Procyon observed with ESO-UVES between 4700 A and 6800 A. The new
log(gf)-values in SpectroWeb are improved over the values offered in the online
Vienna Atomic Line Database (VALD). We find for neutral iron-group elements,
such as Fe I, Ni I, Cr I, and Ti I, a statistically significant over-estimation
of the VALD log(gf)-values for weak absorption lines with normalized central
line depths below 15 %. For abundant lighter elements (e.g. Mg I and Ca I) this
trend is statistically not significantly detectable, with the exception of Si I
for which the log(gf)-values of 60 weak and medium-strong lines are
substantially decreased to best fit the observed spectra. The newly measured
log(gf)-values are available in the SpectroWeb database at
http://spectra.freeshell.org which interactively displays the observed and
computed stellar spectra, together with corresponding atomic line data.


title:
Energy dependence of forward 1S0 diproton production in the pp -> pp pi0
  reaction

abstract:
  The pp -> {pp}_s pi0 differential cross section has been measured with the
ANKE spectrometer at COSY-Juelich for seven proton beam energies T_p between
0.5 and 1.97 GeV. By selecting proton pairs with an excitation energy of less
than 3 MeV it is ensured that the final {pp}_s system is in the 1S0 state. In
the measured region of theta_{pp}^{cm} < 18 deg, the data reveal a forward dip
for T_p =< 1.4 GeV whereas a forward peaking is seen at 1.97 GeV. The energy
dependence of the forward cross section shows a broad peak in the 0.6-0.8 GeV
region, probably associated with Delta(1232) excitation, and a minimum at 1.4
GeV. Some of these features are similar to those observed for the spin-isospin
partner reaction, pp -> d pi+. However, the ratio of the forward differential
cross sections of the two reactions shows a significant suppression of single
pion production associated with a spin--singlet final nucleon pair.


title: Symbolic Manipulators Affect Mathematical Mindsets

abstract:
  Symbolic calculators like Mathematica are becoming more commonplace among
upper level physics students. The presence of such a powerful calculator can
couple strongly to the type of mathematical reasoning students employ. It does
not merely offer a convenient way to perform the computations students would
have otherwise wanted to do by hand. This paper presents examples from the work
of upper level physics majors where Mathematica plays an active role in
focusing and sustaining their thought around calculation. These students still
engage in powerful mathematical reasoning while they calculate but struggle
because of the narrowed breadth of their thinking. Their reasoning is drawn
into local attractors where they look to calculation schemes to resolve
questions instead of, for example, mapping the mathematics to the physical
system at hand. We model the influence of Mathematica as an integral part of
the constant feedback that occurs in how students frame, and hence focus, their
work.


title: Liouville equations for neutrino distribution matrices

abstract:
  The classical notion of a single-particle scalar distribution function or
phase space density can be generalized to a matrix in order to accommodate
superpositions of states of discrete quantum numbers, such as neutrino
mass/flavor. Such a `neutrino distribution matrix' is thus an appropriate
construct to describe a neutrino gas that may vary in space as well as time and
in which flavor mixing competes with collisions. The Liouville equations obeyed
by relativistic neutrino distribution matrices, including the spatial
derivative and vacuum flavor mixing terms, can be explicitly but elegantly
derived in two new ways: from a covariant version of the familiar simple model
of flavor mixing, and from the Klein-Gordon equations satisfied by a quantum
`density function' (mean value of paired quantum field operators). Associated
with the latter derivation is a case study in how the joint position/momentum
dependence of a classical gas (albeit with Fermi statistics) emerges from a
formalism built on quantum fields.


title:
Implementation, Compilation, Optimization of Object-Oriented Languages,
  Programs and Systems - Report on the Workshop ICOOOLPS'2007 at ECOOP'07

abstract:
  ICOOOLPS'2007 was the second edition of the ECOOP-ICOOOLPS workshop. ICOOOLPS
intends to bring researchers and practitioners both from academia and industry
together, with a spirit of openness, to try and identify and begin to address
the numerous and very varied issues of optimization. After a first successful
edition, this second one put a stronger emphasis on exchanges and discussions
amongst the participants, progressing on the bases set last year in Nantes. The
workshop attendance was a success, since the 30-people limit we had set was
reached about 2 weeks before the workshop itself. Some of the discussions (e.g.
annotations) were so successful that they would required even more time than we
were able to dedicate to them. That's one area we plan to further improve for
the next edition.


title: How to control nonlinear effects in Binder cumulants

abstract:
  We point out that ignoring nonlinear effects in finite size scaling may lead
to errors in estimates of the critical temperature and Binder cumulants. We
show that the order of magnitude of these effects can be estimated from data at
relatively small volume. Using this estimate, we propose to use linear fits in
increasingly small temperature regions as the volume is increased (rather than
using a fixed temperature interval). The choice of the exact coefficient of
proportionality can be optimized and reveals interesting crossing patterns
among estimates. We show that the new procedure works very well for Dyson's
hierarchical model. We discuss applications of the method for 3 dimensional
spin models and finite temperature lattice gauge theories and comment on the
nonlinear effects for existing calculations.


title:
Nuclear alpha-particle condensates: Definitions, occurrence conditions,
  and consequences

abstract:
  There has been a recent flurry of interest in the possibility of condensates
of $\alpha$-particles in nuclei. In this letter we discuss occurrence
conditions for such states. Using the quantality condition of Mottelson we show
that condensates are only marginally expected in $\alpha$-particle states. We
proceed to demonstrate that few-body nuclear condensates are ill-defined, and
emphasize the conflict between $\alpha$-localization and $\alpha$-condensate
formation. We also explore the connection between Ikeda diagrams, linear
chains, and Tonks-Girardeau gases. Our findings show that no new information is
contained in the approximations of nuclear states as $\alpha$-cluster
condensates. Furthermore, condensates of more than three $\alpha$-particles are
very unlikely to exist due to couplings to other degrees of freedom.


title: The Highest Redshift Relativistic Jets

abstract:
  We describe our efforts to understand large-scale (10's-100's kpc)
relativistic jet systems through observations of the highest-redshift quasars.
Results from a VLA survey search for radio jets in ~30 z>3.4 quasars are
described along with new Chandra observations of 4 selected targets.


title: Generating AdS String Solutions

abstract:
  We use a Pohlmeyer type reduction to generate classical string solutions in
AdS spacetime. In this framework we describe a correspondence between spikes in
AdS_3 and soliton profiles of the sinh-Gordon equation. The null cusp string
solution and its closed spinning string counterpart are related to the
sinh-Gordon vacuum. We construct classical string solutions corresponding to
sinh-Gordon solitons, antisolitons and breathers by the inverse scattering
technique. The breather solutions can also be reproduced by the sigma model
dressing method.


title: The Hartree-Fock ground state of the three-dimensional electron gas

abstract:
  In 1962, Overhauser showed that within Hartree-Fock (HF) the electron gas is
unstable to a spin density wave (SDW) instability. Determining the true HF
ground state has remained a challenge. Using numerical calculations for finite
systems and analytic techniques, we study the HF ground state of the 3D
electron gas. At high density, we find broken spin symmetry states with a
nearly constant charge density. Unlike previously discussed spin wave states,
the observed wave vector of the SDW is smaller than $2 k_F$. The
broken-symmetry state originates from pairing instabilities at the Fermi
surface, a model for which is proposed.


title:
Parton correlation functions and factorization in deep inelastic
  scattering

abstract:
  We outline the basic properties of a pertubative QCD factorization formalism
that maintains exact over-all kinematics in both the initial and final states.
Such a treatment requires the use of non-perturbative factors that depend on
all components of parton four-momentum. These objects are referred to as parton
correlation functions. We describe the complications faced in defining parton
correlation functions and discuss recent progress. Emphasis is placed on the
need for precise operator definitions in a complete derivation of
factorization.


title: Simple de Sitter Solutions

abstract:
  We present a framework for de Sitter model building in type IIA string
theory, illustrated with specific examples. We find metastable dS minima of the
potential for moduli obtained from a compactification on a product of two Nil
three-manifolds (which have negative scalar curvature) combined with
orientifolds, branes, fractional Chern-Simons forms, and fluxes. As a discrete
quantum number is taken large, the curvature, field strengths, inverse volume,
and four dimensional string coupling become parametrically small, and the de
Sitter Hubble scale can be tuned parametrically smaller than the scales of the
moduli, KK, and winding mode masses. A subtle point in the construction is that
although the curvature remains consistently weak, the circle fibers of the
nilmanifolds become very small in this limit (though this is avoided in
illustrative solutions at modest values of the parameters). In the simplest
version of the construction, the heaviest moduli masses are parametrically of
the same order as the lightest KK and winding masses. However, we provide a
method for separating these marginally overlapping scales, and more generally
the underlying supersymmetry of the model protects against large corrections to
the low-energy moduli potential.


title:
Manipulation of single-photon states encoded in transverse spatial
  modes: possible and impossible tasks

abstract:
  Controlled generation and manipulation of photon states encoded in their
spatial degrees of freedom is a crucial ingredient in many quantum information
tasks exploiting higher-than-two dimensional encoding. Here, we prove the
impossibility to arbitrarily modify $d$-level state superpositions (qu$d$its)
for $d>2$, encoded in the transverse modes of light, with optical components
associated to the group of symplectic transforms (Gaussian operations).
Surprisingly, we also provide an explicit construction of how non-Gaussian
operations acting on mode subspaces do enable to overcome the limit $d=2$. In
addition, this set of operations realizes the full SU(3) algebra.


title: Gamma-entropy cost for scalar conservation laws

abstract:
  We are concerned with a control problem related to the vanishing viscosity
approximation to scalar conservation laws. We investigate the
$\Gamma$-convergence of the control cost functional, as the viscosity
coefficient tends to zero. A first order $\Gamma$-limit is established, which
characterizes the measure-valued solutions to the conservation laws as the
zeros of the $\Gamma$-limit. A second order $\Gamma$-limit is then
investigated, providing a characterization of entropic solutions to
conservation laws as the zeros of the $\Gamma$-limit.


title:
A model of non-perturbative gluon emission in an initial state parton
  shower

abstract:
  We consider a model of transverse momentum production in which
non-perturbative smearing takes place throughout the perturbative evolution, by
a simple modification to an initial state parton shower algorithm. Using this
as the important non-perturbative ingredient, we get a good fit to data over a
wide range of energy. Combining it with the non-perturbative masses and cutoffs
that are a feature of conventional parton showers also leads to a reasonable
fit. We discuss the extrapolation to the LHC.


title: Hard X-ray flares in IGR J08408-4503 unveil clumpy stellar winds

abstract:
  Context : A 1000-s flare from a new hard X-ray transient, IGR J08408-4503,
was observed by INTEGRAL on May 15, 2006 during the real-time routine
monitoring of IBIS/ISGRI images performed at the INTEGRAL Science Data Centre.
The flare, detected during a single one-hour long pointing, peaked at 250 mCrab
in the 20-40 keV energy range.
  Aims : Multi-wavelength observations, combining high-energy and optical data,
were used to unveil the nature of IGR J08408-4503.
  Methods : A search in all INTEGRAL public data for other bursts from IGR
J08408-4503 was performed, and the detailed analysis of another major flare is
presented. The results of two Swift Target of Opportunity observations are also
described. Finally, a study of the likely optical counterpart, HD 74194, is
provided.
  Results : IGR J08408-4503 is very likely a supergiant fast X-ray transient
(SFXT) system. The system parameters indicate that the X-ray flares are
probably related to the accretion of wind clumps on a compact object orbiting
about 1E13 cm from the supergiant HD 74194. The clump mass loss rate is of the
order of 1E-6 solar mass/yr.
  Conclusions : Hard X-ray flares from SFXTs allow to probe the stellar winds
of massive stars, and could possibly be associated with wind perturbations due
to line-driven instabilities.


title: Four-dimensional graphene and chiral fermions

abstract:
  Motivated by the description of the graphene electronic structure in terms of
the relativistic Dirac equation, a generalization to four dimensions yields a
strictly local fermion action describing two species and possessing an exact
chiral symmetry. This is the minimum number of species required by the well
known ``no-go'' theorems.


title:
Modelling the spectral energy distribution of ULIRGs II: The energetic
  environment and the dense interstellar medium

abstract:
  We fit the near-infrared to radio spectral energy distributions of 30
luminous and ultra-luminous infrared galaxies with pure starburst models or
models that include both starburst and AGN components to determine important
physical parameters for this population of objects. In particular we constrain
the optical depth towards the luminosity source, the star formation rate, the
star formation efficiency and the AGN fraction. We find that although about
half of our sample have best-fit models that include an AGN component, only 30%
have an AGN which accounts for more than 10% of the infrared luminosity,
whereas all have an energetically dominant starburst. Our derived AGN fractions
are generally in good agreement other measurements based in the mid-infrared
line ratios measured by Spitzer IRS, but lower than those derived from PAH
equivalent widths or the mid-infrared spectral slope. Our models determine the
mass of dense molecular gas via the extinction required to reproduce the SED.
Assuming that this mass is that traced by HCN, we reproduce the observed linear
relation between HCN and infrared luminosities found by Gao & Solomon. We also
find that the star formation efficiency, defined as the current star formation
rate per unit of dense molecular gas mass, is enhanced in the ULIRGs phase. If
the evolution of ULIRGs includes a phase in which an AGN contributes an
important fraction to the infrared luminosity, this phase should last an order
of magnitude less time than the starburst phase. Because the mass of dense
molecular gas which we derive is consistent with observations of the HCN
molecule,it should be possible to estimate the mass of dense, star-forming
molecular gas in such objects when molecular line data are not available.


title:
On the Properties of Plastic Ablators in Laser-Driven Material Dynamics
  Experiments

abstract:
  Radiation hydrodynamics simulations were used to study the effect of plastic
ablators in laser-driven shock experiments. The sensitivity to composition and
equation of state was found to be 5-10% in ablation pressure. As was found for
metals, a laser pulse of constant irradiance gave a pressure history which
decreased by several percent per nanosecond. The pressure history could be made
more constant by adjusting the irradiance history. The impedance mismatch with
the sample gave an increase o(100%) in the pressure transmitted into the
sample, for a reduction of several tens of percent in the duration of the peak
load applied to the sample, and structured the release history by adding a
release step to a pressure close to the ablation pressure. Algebraic relations
were found between the laser pulse duration, the ablator thickness, and the
duration of the peak pressure applied to the sample, involving quantities
calculated from the equations of state of the ablator and sample using shock
dynamics.


title:
Kinematic Constraints on Formation of Bound States of Cosmic Strings -
  Field Theoretical Approach

abstract:
  Superstring theory predicts the potential formation of string networks with
bound states ending in junctions. Kinematic constraints for junction formation
have been derived within the Nambu-Goto thin string approximation. Here we test
these constraints numerically in the framework of the Abelian-Higgs model in
the Type-I regime and report on good agreement with the analytical predictions.
We also demonstrate that strings can effectively pass through each other when
they meet at speeds slightly above the critical velocity permitting bound state
formation. This is due to reconnection effects that are beyond the scope of the
Nambu-Goto approximation.


title: Lambda-RBAC: Programming with Role-Based Access Control

abstract:
  We study mechanisms that permit program components to express role
constraints on clients, focusing on programmatic security mechanisms, which
permit access controls to be expressed, in situ, as part of the code realizing
basic functionality. In this setting, two questions immediately arise: (1) The
user of a component faces the issue of safety: is a particular role sufficient
to use the component? (2) The component designer faces the dual issue of
protection: is a particular role demanded in all execution paths of the
component? We provide a formal calculus and static analysis to answer both
questions.


title: Proton Decay and Flavor Violating Thresholds in SO(10) Models

abstract:
  Discovery of neutrino mass has put the spotlight on supersymmetric SO(10) as
a natural candidate for grand unification of forces and matter. However, the
suppression of proton decay is a major problem in any supersymmetric grand
unified models. In this paper we show how to alleviate this problem by simple
threshold effect which raises the colored Higgsino masses and the grand
unification scale to \gtrsim 10^{17} GeV. There exist only four types of fields
arising from different SO(10) representations which can generate this kind of
threshold effects. Some of these fields also generate a sizable flavor
violation in the quark sector compared to the lepton sector. The b-\tau
unification can work in these types of models even for intermediate values of
tan\beta.


title: Light nuclei from chiral EFT interactions

abstract:
  Recent developments in nuclear theory allow us to make a connection between
quantum chromodynamics (QCD) and low-energy nuclear physics. First, chiral
effective field theory (chiEFT) provides a natural hierarchy to define
two-nucleon (NN), three-nucleon (NNN), and even four-nucleon interactions.
Second, ab initio methods have been developed capable to test these
interactions for light nuclei. In this contribution, we discuss ab initio
no-core shell model (NCSM) calculations for s-shell and p-shell nuclei with NN
and NNN interactions derived within chiEFT.


title:
Quantum covariance, quantum Fisher information and the uncertainty
  principle

abstract:
  In this paper the relation between quantum covariances and quantum Fisher
informations are studied. This study is applied to generalize a recently proved
uncertainty relation based on quantum Fisher information. The proof given
hereconsiderably simplifies the previously proposed proofs and leads to more
general inequalities.


title: Towards an S-matrix Description of Gravitational Collapse

abstract:
  Extending our previous results on trans-Planckian ($Gs \gg \hbar$) scattering
of light particles in quantum string-gravity we present a calculation of the
corresponding S-matrix from the region of large impact parameters ($b \gg
G\sqrt{s}>\lambda_s$) down to the regime where classical gravitational collapse
is expected to occur. By solving the semiclassical equations of a previously
introduced effective-action approximation, we find that the perturbative
expansion around the leading eikonal result diverges at a critical value $b =
b_c = O(G\sqrt{s})$, signalling the onset of a new (black-hole related?)
regime. We then discuss the main features of our explicitly unitary S-matrix --
and of the associated effective metric -- down to (and in the vicinity of) $b =
b_c$, and present some ideas and results on its extension all the way to the $
b \to 0$ region. We find that for $b<b_c$ the physical field solutions are
complex-valued and the S-matrix shows additional absorption, related to a new
production mechanism. The field solutions themselves are, surprisingly,
everywhere regular, suggesting a quantum-tunneling -- rather than a
singular-geometry -- situation.


title: Velocity and Distribution of Primordial Neutrinos

abstract:
  The Cosmic Neutrinos Background (\textbf{CNB}) are Primordial Neutrinos
decoupled when the Universe was very young. Its detection is complicated,
especially if we take into account neutrino mass and a possible breaking of
Lorentz Invariance at high energy, but has a fundamental relevance to study the
Big-Bang. In this paper, we will see that a Lorentz Violation does not produce
important modification, but the mass does. We will show how the neutrinos
current velocity, with respect to comobile system to Universe expansion, is of
the order of 1065 $[\frac{km}{s}]$, much less than light velocity. Besides, we
will see that the neutrinos distribution is complex due to Planetary motion.
This prediction differs totally from the usual massless case, where we would
get a correction similar to the Dipolar Moment of the \textbf{CMB}.


title: Quantum Algorithms and Complexity for Continuous Problems

abstract:
  Most continuous mathematical formulations arising in science and engineering
can only be solved numerically and therefore approximately. We shall always
assume that we're dealing with a numerical approximation to the solution. There
are two major motivations for studying quantum algorithms and complexity for
continuous problems. 1. Are quantum computers more powerful than classical
computers for important scientific problems? How much more powerful? 2. Many
important scientific and engineering problems have continuous formulations. To
answer the first question we must know the classical computational complexity
of the problem. Knowing the classical complexity of a continuous problem we
obtain the quantum computation speedup if we know the quantum complexity. If we
know an upper bound on the quantum complexity through the cost of a particular
quantum algorithm then we can obtain a lower bound on the quantum speedup.
Regarding the second motivation, in this article we'll report on
high-dimensional integration, path integration, Feynman path integration, the
smallest eigenvalue of a differential equation, approximation, partial
differential equations, ordinary differential equations and gradient
estimation. We'll also briefly report on the simulation of quantum systems on a
quantum computer.


title: Gravitational settling of 22Ne and white dwarf evolution

abstract:
  We study the effects of the sedimentation of the trace element 22Ne in the
cooling of white dwarfs. In contrast with previous studies, which adopted a
simplified treatment of the effects of 22Ne sedimentation, this is done
self-consistently for the first time, using an up-to-date stellar evolutionary
code in which the diffusion equation is coupled with the full set of equations
of stellar evolution. Due the large neutron excess of 22Ne, this isotope
rapidly sediments in the interior of the white dwarf. Although we explore a
wide range of parameters, we find that using the most reasonable assumptions
concerning the diffusion coefficient and the physical state of the white dwarf
interior the delay introduced by the ensuing chemical differentation is minor
for a typical 0.6 Msun white dwarf. For more massive white dwarfs, say M_Wd
about 1.0 Msun, the delay turns out to be considerably larger. These results
are in qualitatively good accord with those obtained in previous studies, but
we find that the magnitude of the delay introduced by 22Ne sedimentation was
underestimated by a factor of about 2. We also perform a preliminary study of
the impact of 22Ne sedimentation on the white dwarf luminosity function.
Finally, we hypothesize as well on the possibility of detecting the
sedimentation of 22Ne using pulsating white dwarfs in the appropriate effective
temperature range with accurately determined rates of change of the observed
periods.


title: Relaxation phenomena at criticality

abstract:
  The collective behaviour of statistical systems close to critical points is
characterized by an extremely slow dynamics which, in the thermodynamic limit,
eventually prevents them from relaxing to an equilibrium state after a change
in the thermodynamic control parameters. The non-equilibrium evolution
following this change displays some of the features typically observed in
glassy materials, such as ageing, and it can be monitored via dynamic
susceptibilities and correlation functions of the order parameter, the scaling
behaviour of which is characterized by universal exponents, scaling functions,
and amplitude ratios. This universality allows one to calculate these
quantities in suitable simplified models and field-theoretical methods are a
natural and viable approach for this analysis. In addition, if a statistical
system is spatially confined, universal Casimir-like forces acting on the
confining surfaces emerge and they build up in time when the temperature of the
system is tuned to its critical value. We review here some of the theoretical
results that have been obtained in recent years for universal quantities, such
as the fluctuation-dissipation ratio, associated with the non-equilibrium
critical dynamics, with particular focus on the Ising model with Glauber
dynamics in the bulk. The non-equilibrium dynamics of the Casimir force acting
in a film is discussed within the Gaussian model.


title: First Calculation of Hyperon Axial Couplings from Lattice QCD

abstract:
  In this work, we report the first lattice calculation of hyperon axial
couplings, using the 2+1-flavor MILC configurations and domain-wall fermion
valence quarks. Both the $\Sigma$ and $\Xi$ axial couplings are computed for
the first time in lattice QCD. In particular we find that $g_{\Sigma\Sigma} =
0.450(21)_{\rm stat}(27)_{\rm syst}$ and $g_{\Xi\Xi} = -0.277(15)_{\rm
stat}(19)_{\rm syst}$.


title:
On the geometry and the moduli space of beta-deformed quiver gauge
  theories

abstract:
  We consider a class of super-conformal beta-deformed N=1 gauge theories dual
to string theory on $AdS_5 \times X$ with fluxes, where $X$ is a deformed
Sasaki-Einstein manifold. The supergravity backgrounds are explicit examples of
Generalised Calabi-Yau manifolds: the cone over $X$ admits an integrable
generalised complex structure in terms of which the BPS sector of the gauge
theory can be described. The moduli spaces of the deformed toric N=1 gauge
theories are studied on a number of examples and are in agreement with the
moduli spaces of D3 and D5 static and dual giant probes.


title:
Revisiting the deconfinement phase transition in SU(4) Yang-Mills theory
  in 2+1 dimensions

abstract:
  In order to deepen our understanding of the nature of the deconfinement phase
transition for various gauge groups, we investigate SU(4) Yang-Mills theory in
2+1 dimensions. We find that the transition is weakly first order. We perform
extensive Monte Carlo simulations on lattices with temporal extent N_t = 3, 4
and 5, and spatial sizes up to N_s = 20 N_t. We observe coexistence of confined
and deconfined phases at the critical temperature, and finite-size scaling
shows consistency with first order exponents. The continuum extrapolation of
the latent heat yields L_h/T_c^3=0.188(17).


abstract:
  Generalized statistical models of voids and hierarchical structure in
cosmology are developed. The often quoted negative binomial model and
frequently used thermodynamic model are shown to be special cases of a more
general distribution which contains a parameter "a". The parameter is related
to the Levy index alpha and the Fisher critical exponent tau, the latter
describing the power law fall off of clumps of matter around a phase
transition. The parameter"a", exponent tau, or index alpha can be obtained from
properties of a void scaling function. A stochastic probability variable "p" is
introduced into a statistical model which represent the adhesive growth of
galaxy structure. For p<1/2, the galaxy count distribution decays exponential
fast with size. For p>1/2, an adhesive growth can go on indefinitely thereby
forming an infinite supercluster. At p=1/2 a scale free power law distribution
for the galaxy count distribution is present. The stochastic description also
leads to consequences that have some parallels with cosmic string results,
percolation theory and phase transitions.


title:
The $\overline\partial$-cohomology groups, holomorphic Morse
  inequalities, and finite type conditions

abstract:
  We study spectral behavior of the complex Laplacian on forms with values in
the $k^{\text{th}}$ tensor power of a holomorphic line bundle over a smoothly
bounded domain with degenerated boundary in a complex manifold. In particular,
we prove that in the two dimensional case, a pseudoconvex domain is of finite
type if and only if for any positive constant $C$, the number of eigenvalues of
the $\overline\partial$-Neumann Laplacian less than or equal to $Ck$ grows
polynomially as $k$ tends to infinity.


title:
Locality and low-dimensions in the prediction of natural experience from
  fMRI

abstract:
  Functional Magnetic Resonance Imaging (fMRI) provides dynamical access into
the complex functioning of the human brain, detailing the hemodynamic activity
of thousands of voxels during hundreds of sequential time points. One approach
towards illuminating the connection between fMRI and cognitive function is
through decoding; how do the time series of voxel activities combine to provide
information about internal and external experience? Here we seek models of fMRI
decoding which are balanced between the simplicity of their interpretation and
the effectiveness of their prediction. We use signals from a subject immersed
in virtual reality to compare global and local methods of prediction applying
both linear and nonlinear techniques of dimensionality reduction. We find that
the prediction of complex stimuli is remarkably low-dimensional, saturating
with less than 100 features. In particular, we build effective models based on
the decorrelated components of cognitive activity in the classically-defined
Brodmann areas. For some of the stimuli, the top predictive areas were
surprisingly transparent, including Wernicke's area for verbal instructions,
visual cortex for facial and body features, and visual-temporal regions for
velocity. Direct sensory experience resulted in the most robust predictions,
with the highest correlation ($c \sim 0.8$) between the predicted and
experienced time series of verbal instructions. Techniques based on non-linear
dimensionality reduction (Laplacian eigenmaps) performed similarly. The
interpretability and relative simplicity of our approach provides a conceptual
basis upon which to build more sophisticated techniques for fMRI decoding and
offers a window into cognitive function during dynamic, natural experience.


title:
On the Evolution of and High-Energy Emission from GHz-Peaked-Spectrum
  Sources

abstract:
  Here we discuss evolution and broad-band emission of compact (< kpc) lobes in
young radio sources. We propose a simple dynamical description for these
objects, consisting of a relativistic jet propagating into a uniform gaseous
medium in the central parts of an elliptical host. In the framework of the
proposed model, we follow the evolution of ultrarelativistic electrons injected
from a terminal hotspot of a jet to expanding lobes, taking into account their
adiabatic energy losses as well as radiative cooling. This allows us to discuss
the broad-band lobe emission of young radio sources. In particular, we argue
that the observed spectral turnover in the radio synchrotron spectra of these
objects cannot originate from the synchrotron self-absorption process but is
most likely due to free-free absorption effects connected with neutral clouds
of interstellar medium engulfed by the expanding lobes and photoionized by
active centers. We also find a relatively strong and complex high-energy
emission component produced by inverse-Compton up-scattering of various
surrounding photon fields by the lobes' electrons. We argue that such high
energy radiation is strong enough to account for several observed properties of
GHz-peaked-spectrum (GPS) radio galaxies at UV and X-ray frequencies. In
addition, this emission is expected to extend up to GeV (or possibly even TeV)
photon energies and can thus be probed by several modern gamma-ray instruments.
In particular, we suggest that GPS radio galaxies should constitute a
relatively numerous class of extragalactic sources detected by GLAST.


title: Finite volume schemes on Lorentzian manifolds

abstract:
  We investigate the numerical approximation of (discontinuous) entropy
solutions to nonlinear hyperbolic conservation laws posed on a Lorentzian
manifold. Our main result establishes the convergence of monotone and
first-order finite volume schemes for a large class of (space and time)
triangulations. The proof relies on a discrete version of entropy inequalities
and an entropy dissipation bound, which take into account the manifold geometry
accurately and generalize techniques and estimates that were known in the
(flat) Euclidian setting, only. The strong convergence of the scheme then is
then a consequence of the well-posed theory recently developed by Ben-Artzi and
LeFloch for conservation laws on manifolds.


title:
Fractional quantum Hall effect and electron correlations in partially
  filled first excited Landau level

abstract:
  We present a quantitative study of most prominent incompressible quantum Hall
states in the partially filled first excited Landau level (LL1) which have been
recently studied experimentally by Choi et al. The pseudopotential describing
the electron - electron interaction in LL1 is harmonic at short range. It
produces a series of incompressible states which is different from its LL0
counterpart. The numerical data indicate that the most prominent states
$\nu={5/2}$, 7/3, and 8/3 are not produced by Laughlin correlated electrons,
but result from a tendency of electrons to form pairs or larger clusters which
eventually become Laughlin correlated. States with smaller gaps at filling
factors 14/5, 16/7, 11/5, 19/7 are Laughlin correlated electron or hole states
and fit Jain's sequence of filled $\rm{CF}^4$ levels.


title:
Conformal Ward identities for Wilson loops and a test of the duality
  with gluon amplitudes

abstract:
  Planar gluon amplitudes in N=4 SYM are remarkably similar to expectation
values of Wilson loops made of light-like segments. We argue that the latter
can be determined by making use of the conformal symmetry of the gauge theory,
broken by cusp anomalies. We derive the corresponding anomalous conformal Ward
identities valid to all loops and show that they uniquely fix the form of the
finite part of a Wilson loop with n cusps (up to an additive constant) for n=4
and n=5 and reduce the freedom in it to a function of conformal invariants for
n>=6. We also present an explicit two-loop calculation for n=5. The result
confirms the form predicted by the Ward identities and exactly matches the
finite part of the two-loop five-gluon planar MHV amplitude. This constitutes
another non-trivial test of the Wilson loop/gluon amplitude duality.


title:
Evaluating the Utility of Anonymized Network Traces for Intrusion
  Detection

abstract:
  Anonymization is the process of removing or hiding sensitive information in
logs. Anonymization allows organizations to share network logs while not
exposing sensitive information. However, there is an inherent trade off between
the amount of information revealed in the log and the usefulness of the log to
the client (the utility of a log). There are many anonymization techniques, and
there are many ways to anonymize a particular log (that is, which fields to
anonymize and how). Different anonymization policies will result in logs with
varying levels of utility for analysis. In this paper we explore the effect of
different anonymization policies on logs. We provide an empirical analysis of
the effect of varying anonymization policies by looking at the number of alerts
generated by an Intrusion Detection System. This is the first work to
thoroughly evaluate the effect of single field anonymization policies on a data
set. Our main contributions are to determine a set of fields that have a large
impact on the utility of a log.


title: Massive states as the relevant deformations of gravitating branes

abstract:
  Five-dimensional theories manifesting spontaneous brane generation are
discussed in a gravitational context. Without gravity, the IR dynamics of the
brane fluctuation below the brane tension scale is described by an effective
theory for the Nambu-Goldstone modes. When gravity is properly taken into
account the long distance dynamics changes. The spontaneous breaking of local
translational invariance triggers the formation of massive representations via
the Higgs mechanism and induces the appearance of new mass scales in the IR.
These scales can in principle depend on other fundamental parameters besides
the brane tension and the Planck scale. In noncompact extra dimensions the
massive states are found to be scalar bound states. We obtain explicit
expressions for their propagator and show that their masses depend on the brane
width and are thus much heavier than expected. We present an exactly solvable
model which captures the main features of the gravitational system.


title: Photometric properties of Local Volume dwarf galaxies

abstract:
  We present surface photometry and metallicity measurements for 104 nearby
dwarf galaxies imaged with the Advanced Camera for Surveys and Wide Field and
Planetary Camera 2 aboard the Hubble Space Telescope.
  In addition, we carried out photometry for 26 galaxies of the sample and for
Sextans B on images of the Sloan Digital Sky Survey. Our sample comprises dwarf
spheroidal, irregular and transition type galaxies located within ~10 Mpc in
the field and in nearby groups: M81, Centaurus A, Sculptor, and Canes Venatici
I cloud. It is found that the early-type galaxies have on average higher
metallicity at a given luminosity in comparison to the late-type objects. Dwarf
galaxies with M_B > -12 -- -13 mag deviate toward larger scale lengths from the
scale length -- luminosity relation common for spiral galaxies, h \propto
L^{0.5}_B. The following correlations between fundamental parameters of the
galaxies are consistent with expectations if there is pronounced gas-loss
through galactic winds: 1) between the luminosity of early-type dwarf galaxies
and the mean metallicity of constituent red giant branch stars, Z ~ L^0.4, 2)
between mean surface brightness within the 25 mag/sq.arcsec isophote and the
corresponding absolute magnitude in the V and I bands, SB_25 ~ 0.3 M_25, and 3)
between the central surface brightness (or effective surface brightness) and
integrated absolute magnitude of galaxies in the V and I bands, SB_0 ~ 0.5 M_L,
SB_e ~ 0.5 M_e. The knowledge of basic photometric parameters for a large
sample of dwarf galaxies is essential for a better understanding of their
evolution.


title: Effective Field Theories for Heavy Quarkonium

abstract:
  We briefly review how nonrelativistic effective field theories give us a
definition of the QCD potentials and a coherent field theory derived quantum
mechanical scheme to calculate the properties of bound states made by two or
more heavy quarks. In this framework heavy quarkonium properties depend only on
the QCD parameters (quark masses and $\als$) and nonpotential corrections are
systematically accounted for. The relation between the form of the
nonperturbative potentials and the low energy QCD dynamics is also discussed.


title: Superinduction for pattern groups

abstract:
  It is well-known that the representation theory of the finite group of
unipotent upper-triangular matrices $U_n$ over a finite field is a wild
problem. By instead considering approximately irreducible representations
(supercharacters), one obtains a rich combinatorial theory analogous to that of
the symmetric group, where we replace partition combinatorics with
set-partitions. This paper studies Diaconis--Isaacs' concept of superinduction
in pattern groups. While superinduction shares many desirable properties with
usual induction, it no longer takes characters to characters. We begin by
finding sufficient conditions guaranteeing that super-induction is in fact
induction. It turns out for natural embedding of $U_m$ in $U_n$,
super-induction is induction. We conclude with an explicit combinatorial
algorithm for computing this induction analogous to the Pieri-formulas for the
symmetric group.


title:
Four Faint T Dwarfs from the UKIRT Infrared Deep Sky Survey (UKIDSS)
  Southern Stripe

abstract:
  We present the optical and near-infrared photometry and spectroscopy of four
faint T dwarfs newly discovered from the UKIDSS first data release. The sample,
drawn from an imaged area of ~136 square degrees to a depth of Y=19.9 (5-sigma,
Vega), is located in the SDSS Southern Equatorial Stripe, a region of
significant future deep imaging potential. We detail the selection and followup
of these objects, three of which are spectroscopically confirmed brown dwarfs
ranging from type T2.5 to T7.5, and one is photometrically identified as early
T. Their magnitudes range from Y=19.01 to 19.88 with derived distances from 34
to 98 pc, making these among the coldest and faintest brown dwarfs known. The
sample brings the total number of T dwarfs found or confirmed by UKIDSS data in
this region to nine, and we discuss the projected numbers of dwarfs in the
future survey data. We estimate that ~240 early- and late-T dwarfs are
discoverable in the UKIDSS LAS data, falling significantly short of published
model projections and suggesting that IMFs and/or birthrates may be at the low
end of possible models. Thus, deeper optical data has good potential to exploit
the UKIDSS survey depth more fully, but may still find the potential Y dwarf
sample to be extremely rare.


title:
Standard Model Gauging of the WZW Term: Anomalies, Global Currents and
  pseudo-Chern-Simons Interactions

abstract:
  The standard model $SU(2)_L\times U(1)_Y$ gauging of the Wess-Zumino-Witten
term requires a modified counterterm when background fields, needed to generate
the full set of currents, are introduced. The modified counterterm plays an
essential role in properly defining covariant global currents and their
anomalies. For example, it is required in order to correctly derive the gauge
invariant baryon number current and its anomalous divergence. The background
fields can also be promoted to a description of the physical spin-1 vector and
axial-vector mesons in QCD and the counterterm leads to novel interactions.
These are (pseudo-) Chern-Simons terms, such as $\epsilon^{\mu\nu\rho\sigma}
\omega_\mu Z_\nu \partial_\rho A_\sigma$ and $\epsilon^{\mu\nu\rho\sigma}
\rho^{\pm}_\mu W^{\mp}_\nu \partial_\rho A_\sigma$ that mediate new
interactions between neutrinos and photons at finite baryon density.


title: Trajectory of virtual, bound and resonant Efimov states

abstract:
  The pole trajectory of Efimov states for a three-body $\alpha\alpha\beta$
system with $\alpha\alpha$ unbound and $\alpha\beta$ bound is calculated using
a zero-range Dirac-$\delta$ potential. It is showed that a three-body bound
state turns into a virtual one by increasing the $\alpha\beta$ binding energy.
This result is consistent with previous results for three equal mass particles.
The present approach considers the $n-n-^{18}C$ halo nucleus. However, the
results have good perspective to be tested and applied in ultracold atomic
systems, where one can realize such three-body configuration with tunable
two-body interaction.


title:
Comparison of Standard Ruler and Standard Candle constraints on Dark
  Energy Models

abstract:
  We compare the dark energy model constraints obtained by using recent
standard ruler data (Baryon Acoustic Oscillations (BAO) at z=0.2 and z=0.35 and
Cosmic Microwave Background (CMB) shift parameters R and l_a) with the
corresponding constraints obtained by using recent Type Ia Supernovae (SnIa)
standard candle data (ESSENCE+SNLS+HST from Davis et. al.). We find that, even
though both classes of data are consistent with LCDM at the 2\sigma level,
there is a systematic difference between the two classes of data. In
particular, we find that for practically all values of the parameters
(\Omega_0m,\Omega_b) in the 2\sigma range of the the 3-year WMAP data (WMAP3)
best fit, LCDM is significantly more consistent with the SnIa data than with
the CMB+BAO data. For example for (\Omega_0m,\Omega_b)=(0.24,0.042)
corresponding to the best fit values of WMAP3, the dark energy equation of
state parametrization w(z)=w_0 + w_1 (z/(1+z)) best fit is at a 0.5\sigma
distance from LCDM (w_0=-1,w_1=0) using the SnIa data and 1.7\sigma away from
LCDM using the CMB+BAO data. There is a similar trend in the earlier data (SNLS
vs CMB+BAO at z=0.35). This trend is such that the standard ruler CMB+BAO data
show a mild preference for crossing of the phantom divide line w=-1, while the
recent SnIa data favor LCDM. Despite of this mild difference in trends, we find
no statistically significant evidence for violation of the cosmic distance
duality relation \eta \equiv d_L(z)/(d_A(z) (1+z)^2)=1. For example, using a
prior of \Omega_0m=0.24, we find \eta=0.95 \pm 0.025 in the redshift range
0<z<2, which is consistent with distance duality at the 2\sigma level.


title:
Short Duration Gamma-Ray Bursts with Extended Emission from
  Proto-Magnetar Spin-Down

abstract:
  Evidence is growing for a class of gamma-ray bursts (GRBs) characterized by
an initial ~0.1-1 s spike of hard radiation followed, after a ~3-10 s lull in
emission, by a softer period of extended emission lasting ~10-100 s. In a few
well-studied cases, these ``short GRBs with extended emission'' show no
evidence for a bright associated supernova (SN). We propose that these events
are produced by the formation and early evolution of a highly magnetized,
rapidly rotating neutron star (a ``proto-magnetar'') which is formed from the
accretion-induced collapse (AIC) of a white dwarf (WD), the merger and collapse
of a WD-WD binary, or, perhaps, the merger of a double neutron star binary. The
initial emission spike is powered by accretion onto the proto-magnetar from a
small disk that is formed during the AIC or merger event. The extended emission
is produced by a relativistic wind that extracts the rotational energy of the
proto-magnetar on a timescale ~10-100 s. The ~3-10 s delay between the prompt
and extended emission is the time required for the newly-formed proto-magnetar
to cool sufficiently that the neutrino-heated wind from its surface becomes
ultra-relativistic. Because a proto-magnetar ejects little or no Ni56 (< 1e-3
M_sun), these events should not produce a bright SN-like transient. We model
the extended emission from GRB060614 using spin-down calculations of a cooling
proto-magnetar, finding reasonable agreement with observations for a magnetar
with an initial rotation period of ~1 ms and a surface dipole field of ~3e15 G.
If GRBs are indeed produced by AIC or WD-WD mergers, they should occur within a
mixture of both early and late-type galaxies and should not produce strong
gravitational wave emission. An additional consequence of our model is the
existence of X-ray flashes unaccompanied by a bright SN.


title: Dark Matter in the Left Right Twin Higgs Model

abstract:
  In the left-right twin Higgs model, one of the neutral Higgses is a natural
candidate for WIMP dark matter. We analyzed the dark matter relic density in
this framework and identified regions of parameter space that provide the right
amount of dark matter. We also studied the dark matter in the more general
inert Higgs doublet model in which the mass splittings between the dark matter
and other particles do not follow the relations in the left-right twin Higgs
model.


title: Patchy Reconnection in a Y-Type Current Sheet

abstract:
  We study the evolution of the magnetic field in a Y-type current sheet
subject to a brief, localized magnetic reconnection event. The reconnection
produces up- and down-flowing reconnected flux tubes which rapidly decelerate
when they hit the Y-lines and underlying magnetic arcade loops at the ends of
the current sheet. This localized reconnection outflow followed by a rapid
deceleration reproduces the observed behavior of post-CME downflowing coronal
voids. These simulations support the hypothesis that these observed coronal
downflows are the retraction of magnetic fields reconnected in localized
patches in the high corona.


title: A characterization and a generalization of W*-modules

abstract:
  We give a new Banach module characterization of $W^*$-modules, also known as
selfdual Hilbert $C^*$-modules over a von Neumann algebra. This leads to a
generalization of the notion, and the theory, of W*-modules, to the setting
where the operator algebras are $\sigma$-weakly closed algebras of operators on
a Hilbert space. That is, we find the appropriate weak* topology variant of our
earlier notion of {\em rigged modules}, and their theory, which in turn
generalizes the notions of C*-module, and Hilbert space, successively. Our {\em
w*-rigged modules} have canonical `envelopes' which are W*-modules. Indeed,
w*-rigged modules may be defined to be a subspace of a W*-module possessing
certain properties.


title:
Restricting supercharacters of the finite group of unipotent
  uppertriangular matrices

abstract:
  It is well-known that the representation theory of the finite group of
unipotent upper-triangular matrices $U_n$ over a finite field is a wild
problem. By instead considering approximately irreducible representations
(supercharacters), one obtains a rich combinatorial theory analogous to that of
the symmetric group, where we replace partition combinatorics with
set-partitions. This paper studies the supercharacter theory of a family of
subgroups that interpolate between $U_{n-1}$ and $U_n$. We supply several
combinatorial indexing sets for the supercharacters, supercharacter formulas
for these indexing sets, and a combinatorial rule for restricting
supercharacters from one group to another. A consequence of this analysis is a
Pieri-like restriction rule from $U_n$ to $U_{n-1}$ that can be described on
set-partitions (analogous to the corresponding symmetric group rule on
partitions).


title:
Population trapping in three-state quantum loops revealed by Householder
  reflections

abstract:
  Population trapping occurs when a particular quantum-state superposition is
immune to action by a specific interaction, such as the well-known dark state
in a three-state lambda system. We here show that in a three-state loop
linkage, a Hilbert-space Householder reflection breaks the loop and presents
the linkage as a single chain. With certain conditions on the interaction
parameters, this chain can break into a simple two-state system and an
additional spectator state. Alternatively, a two-photon resonance condition in
this Householder-basis chain can be enforced, which heralds the existence of
another spectator state. These spectator states generalize the usual dark state
to include contributions from all three bare basis states and disclose hidden
population trapping effects, and hence hidden constants of motion. Insofar as a
spectator state simplifies the overall dynamics, its existence facilitates the
derivation of analytic solutions and the design of recipes for quantum state
engineering in the loop system. Moreover, it is shown that a suitable sequence
of Householder transformations can cast an arbitrary N-dimensional hermitian
Hamiltonian into a tridiagonal form. The implication is that a general N-state
system, with arbitrary linkage patterns where each state connects to any other
state, can be reduced to an equivalent chainwise-connected system, with
nearest-neighbor interactions only, with ensuing possibilities for discovering
hidden multidimensional spectator states and constants of motion.


title:
Metallicity of the intergalactic medium using pixel statistics: IV.
  Oxygen

abstract:
  We have studied the abundance of oxygen in the IGM by analyzing OVI, CIV,
SiIV, and HI pixel optical depths derived from a set of high-quality VLT and
Keck spectra of 17 QSOs at 2.1 < z < 3.6. Comparing OVI and CIV optical depth
ratios to those in realistic, synthetic spectra drawn from a hydrodynamical
simulation and comparing to existing constraints on [Si/C] places strong
constraints on the ultraviolet background (UVB) model using weak priors on
allowed values of [Si/O]: for example, a quasar-only background yields [Si/O] ~
1.4, highly inconsistent with the [Si/O] ~ 0 expected from nucleosynthetic
yields and with observations of metal-poor stars. Assuming a fiducial
quasar+galaxy UVB consistent with these constraints yields a primary result
that [O/C] = 0.66 +/- 0.06 +/- 0.2; this result pertains to gas with
overdensity >~ 0.2. Consistent results are obtained by similarly comparing OVI
to HI or OVI to SiIV optical depth ratios to simulation values, and also by
directly ionization-correcting OVI optical depths as function of HI optical
depths into [O/H] as a function of density. Subdividing the sample reveals no
evidence for evolution, but low- and high-density samples are inconsistent,
suggesting either density-dependence of [O/C] or -- more likely -- prevalence
of collisionally-ionized gas at high density.