title:
Direct measurements of hydrophobic slippage using double-focus
  fluorescence cross-correlation

abstract:
  We report results of direct measurements of velocity profiles in a
microchannel with hydrophobic and hydrophilic walls, using a new high precision
method of double-focus spacial fluorescence cross-correlation under a confocal
microscope. In the vicinity of both walls the measured velocity profiles do not
turn to zero by giving a plateau of constant velocity. This apparent slip is
proven to be due to a Taylor dispersion, an augmented by shear diffusion of
nanotracers in the direction of flow. Comparing the velocity profiles near the
hydrophobic and hydrophilic walls for various conditions shows that there is a
true slip length due to hydrophobicity. This length, of the order of several
tens of nanometers, is independent on electrolyte concentration and shear rate.


title:
Hierarchical Additive Modeling of Nonlinear Association with Spatial
  Correlations-An Application to Relate Alcohol Outlet Density and Neighborhood
  Assault Rates

abstract:
  Previous studies have suggested a link between alcohol outlets and assaultive
violence. In this paper, we explore the effects of alcohol availability on
assault crimes at the census tract level over time. The statistical analysis is
challenged by several features of the data: (1) the effects of possible
covariates (for example, the alcohol outlet density of each census tract) on
the assaultive crime rates may be complex; (2) the covariates may be highly
correlated with each other; (3) there are a lot of missing inputs in the data;
and (4) spatial correlations exist in the outcome assaultive crime rates. We
propose a hierarchical additive model, where the nonlinear correlations and the
complex interaction effects are modeled using the multiple additive regression
trees (MART) and the spatial variances in the assaultive rates that cannot be
explained by the specified covariates are smoothed trough the Conditional
Autoregressive (CAR) model. We develop a two-stage algorithm that connect the
non-parametric trees with CAR to look for important variables covariates
associated with the assaultive crime rates, while taking account of the spatial
correlations among adjacent census tracts. The proposed methods are applied to
the Los Angeles assaultive data (1990-1999) and compared with traditional
method.


title:
Qregularity and an Extension of Evans-Griffiths Criterion to Vector
  Bundles on Quadrics

abstract:
  Here we define the concept of Qregularity for coherent sheaves on quadrics.
In this setting we prove analogs of some classical properties. We compare the
Qregularity of coherent sheaves on $\Q_n\subset \mathbb P^{n+1}$ with the
Castelnuovo-Mumford regularity of their extension by zero in $\mathbb P^{n+1}$.
We also classify the coherent sheaves with Qregularity $-\infty$. We use our
notion of Qregularity in order to prove an extension of Evans-Griffiths
criterion to vector bundles on Quadrics. In particular we get a new and simple
proof of the Kn\"{o}rrer's characterization of ACM bundles.


title:
Principal eigenvalues for Isaacs operators with Neumann boundary
  conditions

abstract:
  In this paper we show the existence of two principal eigenvalues associated
to general non-convex fully nonlinear elliptic operators with Neumann boundary
conditions in a bounded $C^2$ domain. We study these objects and we establish
some of their basic properties. Finally, Lipschitz regularity, uniqueness and
existence results for the solution of the Neumann problem are given.


title:
Essential Spectrum of Multiparticle Brown-Ravenhall Operators in
  External Field

abstract:
  The essential spectrum of multiparticle Brown-Ravenhall operators is
characterized in terms of two--cluster decompositions for a wide class of
external fields and interparticle interactions and for the systems with
prescribed symmetries.


title: Test of a modified BCS theory performance in the Picket Fence Model

abstract:
  Analyses of a modified BCS (MBCS) theory performance at finite temperatures
in the Picket Fence Model (PFM) for light and heavy systems is presented. Both
symmetric, $\Omega=N$ ($N$ particles on $\Omega$ twice-degenerate levels), and
asymmetric, $\Omega\neq N$, versions of the PFM are considered. The quantities
known exactly from particle-hole symmetry of the $\Omega=N$ PFM are calculated.
Starting from very low temperatures, these quantities are found in dramatic
deviation from the exact values in MBCS results. Consequences of the MBCS
prediction that heating generates a thermal constituent of the pairing gap, are
discussed. Thermodynamical inconsistency of the MBCS is also addressed.


title:
Meson loops in the $f_0(980)$ and $a_0(980)$ radiative decays into
  $\rho$, $\omega$

abstract:
  We calculate the radiative decay widths of the $a_0(980)$ and $f_0(980)$
scalar mesons into $\rho\gamma$ and $\omega\gamma$ considering the dynamically
generated nature of these scalar resonances within the realm of the Chiral
Unitary Approach. The main ingredient in the evaluation of the radiative width
of the scalar mesons are the loops coming from the decay into their constituent
pseudoscalar-pseudoscalar components and the subsequent radiation of the
photon. The dominant diagrams with only pseudoscalar mesons in the loops are
found to be convergent while the divergence of those with a vector meson in the
loop are written in terms of the two meson loop function easily regularizable.
We provide results for all the possible charge channels and obtain results,
with uncertainties, which differ significantly from quark loops models and some
version of vector meson dominance.


title:
A Survey About Nothing: Monitoring a Million Supergiants for Failed
  Supernovae

abstract:
  Extragalactic transient searches have historically been limited to looking
for the appearance of new sources such as supernovae. It is now possible to
carry out a new kind of survey that will do the opposite, that is, search for
the disappearance of massive stars. This will entail the systematic observation
of galaxies within a distance of 10 Mpc in order to watch ~10^6 supergiants.
Reaching this critical number ensures that something will occur yearly, since
these massive stars must end their lives with a core collapse within ~10^6
years. Using deep imaging and image subtraction it is possible to determine the
fates of these stars whether they end with a bang (supernova) or a whimper
(fall out of sight). Such a survey would place completely new limits on the
total rate of all core collapses, which is critical for determining the
validity of supernova models. It would also determine the properties of
supernova progenitors, better characterize poorly understood optical
transients, such as eta Carina-like mass ejections, find and characterize large
numbers of Cepheids, luminous blue variables and eclipsing binaries, and allow
the discovery of any new phenomena that inhabit this relatively unexplored
parameter space.


title: Geometric theta-lifting for the dual pair GSp_{2n}, GSO_{2m}

abstract:
  Let X be a smooth projective curve over an algebraically closed field of
characteristic >2. Consider the dual pair H=GSO_{2m}, G=GSp_{2n} over X, where
H splits over an etale two-sheeted covering of X. Write Bun_G and Bun_H for the
stacks of G-torsors and H-torsors on X. We show that for m\le n (respectively,
for m>n) the theta-lifting functor from D(Bun_H) to D(Bun_G) (respectively,
from D(Bun_G) to D(Bun_H)) commutes with Hecke functors with respect to a
morphism of the corresponding L-groups involving the SL_2 of Arthur. So, they
realize the geometric Langlands functoriality for the corresponding morphisms
of L-groups.
  As an application, we prove a particular case of the geometric Langlands
conjectures for GSp_4. Namely, we construct the automorphic Hecke eigensheaves
on Bun_{GSp_4} corresponding to the endoscopic local systems on X.


title:
Ground state and thermal transitions in Field Induced spin-Supersolid
  Phase

abstract:
  We use a quantum Monte Carlo method to study the ground state and
thermodynamic phase transitions of the spin supersolid phase in the S=1
Heisenberg model with uniaxial anisotropy. The thermal melting of the
supersolid phase shows unqiue signatures in experimentally measurable
observables. This Hamiltonian is a particular case of a more general and
ubiquitous model that describes the low energy spectrum of a class of {\it
isotropic} and {\it frustrated} spin systems. We also discuss some alternative
realizations of spin supersolid states in real magnets.


title: A Periodic Table for Black Hole Orbits

abstract:
  Understanding the dynamics around rotating black holes is imperative to the
success of the future gravitational wave observatories. Although integrable in
principle, test particle orbits in the Kerr spacetime can also be elaborate,
and while they have been studied extensively, classifying their general
properties has been a challenge. This is the first in a series of papers that
adopts a dynamical systems approach to the study of Kerr orbits, beginning with
equatorial orbits. We define a taxonomy of orbits that hinges on a
correspondence between periodic orbits and rational numbers. The taxonomy
defines the entire dynamics, including aperiodic motion, since every orbit is
in or near the periodic set. A remarkable implication of this periodic orbit
taxonomy is that the simple precessing ellipse familiar from planetary orbits
is not allowed in the strong-field regime. Instead, eccentric orbits trace out
precessions of multi-leaf clovers in the final stages of inspiral. Furthermore,
for any black hole, there is some point in the strong-field regime past which
zoom-whirl behavior becomes unavoidable. Finally, we sketch the potential
application of the taxonomy to problems of astrophysical interest, in
particular its utility for computationally intensive gravitational wave
calculations.


title:
Diffraction coefficients of a semi-infinite planar crack embedded in a
  transversely-isotropic space

abstract:
  We have considered a semi-infinite crack embedded in a transversely isotropic
medium and studied two special cases, one, in which the axis of symmetry is
normal to the crack face and the wave incidence is arbitrary and another, in
which the axis lies in the crack plane normal to the edge and the incident wave
vector is also normal to the edge. The problem is of interest in
Non-Destructive Evaluation, because austenitic steels that are found in
claddings and other welds in the nuclear reactors are often modeled as
transversely isotropic. In both of cases, we have expressed the scattered field
in a closed form and computed the corresponding diffraction coefficients.


title: Inelastic Collisions in Optically Trapped Ultracold Metastable Ytterbium

abstract:
  We report measurement of inelastic loss in dense and cold metastable
ytterbium (Yb[$^3P_2$]). Use of an optical far-off-resonance trap enables us to
trap atoms in all magnetic sublevels, removing multichannel collisional trap
loss from the system. Trapped samples of Yb[$^3P_2$] are produced at a density
of 2$\times10^{13}$ cm$^{-3}$ and temperature of 2 $\mu$K. We observe rapid
two-body trap loss of Yb[$^3P_2$] and measure the inelastic collision rate
constant 1.0(3)$\times10^{-11}$ cm$^3$s$^{-1}$. The existence of the
fine-structure changing collisions between atoms in the $^3P_2$ state is
strongly suggested.


title: Life and times of dwarf spheroidal galaxies

abstract:
  We propose a cosmological scenario for the formation and evolution of dwarf
spheroidal galaxies (dSphs), satellites of the Milky Way (MW). An improved
version of the semi-analytical code GAMETE (GAlaxy Merger Tree & Evolution) is
used to follow the dSphs evolution simultaneously with the MW formation,
matching the observed properties of both. In this scenario dSph galaxies
represent fossil objects virializing at z = 7.2 +/- 0.7 (i.e. in the
pre-reionization era z > z_rei = 6) in the MW environment, which at that epoch
has already been pre-enriched up to [Fe/H] ~ -3; their dynamical masses are in
the narrow range M = (1.6 +/- 0.7) x 10^8 M_sun, although a larger spread might
be introduced by a more refined treatment of reionization. Mechanical feedback
effects are dramatic in such low-mass objects, causing the complete blow-away
of the gas ~100 Myr after the formation epoch: 99% of the present-day stellar
mass, M_* = (3 +/- 0.7) x 10^6 M_sun, forms during this evolutionary phase,
i.e. their age is >13 Gyr. Later on, star formation is re-ignited by returned
gas from evolved stars and a second blow-away occurs. The cycle continues for
about 1 Gyr during which star formation is intermittent. At z = 0 the dSph gas
content is M_g = (2.68 +/- 0.97) x 10^4 M_sun. Our results match several
observed properties of Sculptor, used as a template of dSphs: (i) the
Metallicity Distribution Function; (ii) the Color Magnitude Diagram; (iii) the
decrement of the stellar [O/Fe] abundance ratio for [Fe/H] > -1.5; (iv) the
dark matter content and the light-to-mass ratio; (v) the HI gas mass content.


title:
The multi-dimensional pencil phenomenon for Laguerre heat-diffusion
  maximal operators

abstract:
  We investigate in detail the mapping properties of the maximal operator
associated with the heat-diffusion semigroup corresponding to expansions with
respect to multi-dimensional standard Laguerre functions.


title: Scaling Regimes as obtained from the DR5 Sloan Digital Sky Survey

abstract:
  Standard cosmology is based on the assumption that the universe is spatially
homogeneous. However the consensus on a homogeneous matter structure, even on
very large scales, has never been complete. The advantage of correlation
dimension calculations is that they enable one to obtain the transition scale
to a homogeneous distribution, whereas other methods, such as those using the
two-point correlation function, make it hard to exhibit the possible fractal
properties of the Universe matter content. Our purpose is to calculate the
correlation dimension $D_2$, looking for a possible transition to homogeneity,
which would imply $D_2 = 3$. We apply the correlation integral method to the
three dimensional sample composed of 332,876 galaxies which we extract from the
Fifth Data Release of the Sloan Digital Sky Survey. We analyze the raw data up
to the scale $d_{max} = 160$ Mpc, assuming $H_0 = 70$ km s$^{-1}$ Mpc$^{-1}$
and considering three cosmological models in order to test the model dependence
of our method. Using volume limited samples for this range leaves us with about
20,000 galaxies. Applying our method to random maps helps us to calibrate our
results. We obtain a correlation dimension of the galaxy distribution which
seems to increase with scales up to $D_2=3$ reached around 70 Mpc. The results
of our analysis, performed on the largest volume limited sample which can be
extracted from the SDSS catalog, are compatible with those formerly obtained by
other authors. However, to get a more reliable description of the structures at
various scales, we think it will be mandatory to use still larger catalogs than
those which are currently available.


title:
Monocrystalline AlGaAs heterostructures for high-reflectivity high-Q
  micromechanical resonators in the MHz regime

abstract:
  We present high-performance megahertz micromechanical oscillators based on
freestanding epitaxial AlGaAs distributed Bragg reflectors. Compared with
dielectric reflectors, the low mechanical loss of the monocrystalline
heterostructure gives rise to significant improvements in the achievable
mechanical quality factor Q while simultaneously exhibiting near unity
reflectivity. Experimental characterization yields an optical reflectivity
exceeding 99.98% and mechanical quality factors up to 20 000 at 4 K. This
materials system is not only an interesting candidate for optical coatings with
ultralow thermal noise, but also provides a promising path toward quantum
optical control of massive micromechanical mirrors.


title:
Errors in the Quantum Electrodynamic Mass Analysis of Hagelstein and
  Chaudhary

abstract:
  Hagelstein and Chaudhary have recently criticized our low energy nuclear
reaction rates in chemical cells based on our computed electron mass
renormalization for surface electrons of metal hydride electrodes. They further
criticize our electron mass renormalization in exploding wire systems which is
very strange because mass renormalization was {\em never even mentioned} in our
exploding wire work. Here we show that the calculations of Hagelstein and
Chaudhary are erroneous in that they are in conflict with the Gauss law, i.e.
they have arbitrarily removed all Coulomb interactions in electromagnetic
propagators. They have also ignored substantial Ampere interactions in favor of
computing only totally negligible contributions. When the fallacious
considerations of Hagelstein and Chaudhary are clearly exposed, it becomes
evident that our previous calculations remain valid.


title: Linear progress in the complex of curves

abstract:
  We show that a random walk on the mapping class group of an orientable
surface of finite type makes linear progress in the relative metric, which is
quasi-isometric to the complex of curves.


title: Gauge Symmetry Breaking in a Throat Geometry

abstract:
  We analyze behaviour of D3-branes in BGMPZ throat geometry. We show that
although single brane has some of the moduli stabilized multi-brane system
tends to expand and form a bound state. Such a system loses non-abelian gauge
symmetry.


title: Bound on the multiplicity of almost complete intersections

abstract:
  Let $R$ be a polynomial ring over a field of characteristic zero and let $I
\subset R$ be a graded ideal of height $N$ which is minimally generated by
$N+1$ homogeneous polynomials. If $I=(f_1,...,f_{N+1})$ where $f_i$ has degree
$d_i$ and $(f_1,...,f_N)$ has height $N$, then the multiplicity of $R/I$ is
bounded above by $\prod_{i=1}^N d_i - \max\{1, \sum_{i=1}^N (d_i-1) -
(d_{N+1}-1) \}$.


title:
Quasi-realistic heterotic-string models with vanishing one-loop
  cosmological constant and perturbatively broken supersymmetry?

abstract:
  Quasi-realistic string models in the free fermionic formulation typically
contain an anomalous U(1), which gives rise to a Fayet-Iliopoulos D-term that
breaks supersymmetry at the one--loop level in string perturbation theory.
Supersymmetry is traditionally restored by imposing F- and D-flatness on the
vacuum. By employing the standard analysis of flat directions we present a
quasi--realistic three generation string model in which stringent F- and D-flat
solution do not appear to exist to all orders in the superpotential. We
speculate that this result is indicative of the non-existence of supersymmetric
flat F- and D-solutions in this model. We provide some arguments in support of
this scenario and discuss its potential implications. Bose-Fermi degeneracy of
the string spectrum implies that the one--loop partition function and hence the
one-loop cosmological constant vanishes in the model. If our assertion is
correct, this model may represent the first known example with vanishing
cosmological constant and perturbatively broken supersymmetry. We discuss the
distinctive properties of the internal free fermion boundary conditions that
may correspond to a large set of models that share these properties. The
geometrical moduli in this class of models are fixed due to asymmetric boundary
conditions, whereas absence of supersymmetric flat directions would imply that
the supersymmetric moduli are fixed as well and the dilaton may be fixed by
hidden sector nonperturbative effects.


title:
Testing the E_p,i - L_p,iso - T_0.45 correlation on a BeppoSAX and Swift
  sample of gamma-ray bursts

abstract:
  Using a sample of 14 BeppoSAX and 74 Swift GRBs with measured redshift we
tested the correlation between the intrinsic peak energy of the time-integrated
spectrum, E_p,i, the isotropic-equivalent peak luminosity, L_p,iso, and the
duration of the most intense parts of the GRB computed as T_0.45 ("Firmani
correlation"). For 41 out of 88 GRBs we could estimate all of the three
required properties. Apart from 980425, which appears to be a definite outlier
and notoriously peculiar in many respects, we used 40 GRBs to fit the
correlation with the maximum likelihood method discussed by D'Agostini,
suitable to account for the extrinsic scatter in addition to the intrinsic
uncertainties affecting every single GRB. We confirm the correlation. However,
unlike the results by Firmani et al., we found that the correlation does have a
logarithmic scatter comparable with that of the E_p,i-E_iso ("Amati")
correlation. We also find that the slope of the product L_p,iso T_0.45 is equal
to ~0.5, which is consistent with the hypothesis that the E_p,i-L_p,iso-T_0.45
correlation is equivalent to the E_p,i-E_iso correlation (slope ~0.5). We
conclude that, based on presently available data, there is no clear evidence
that the E_p,i-L_p,iso-T_0.45 correlation is different (both in terms of slope
and dispersion) from the E_p,i-E_iso correlation.


title: Can one see entanglement ?

abstract:
  The human eye can detect optical signals containing only a few photons. We
investigate the possibility to demonstrate entanglement with such biological
detectors. While one person could not detect entanglement by simply observing
photons, we discuss the possibility for several observers to demonstrate
entanglement in a Bell-type experiment, in which standard detectors are
replaced by human eyes. Using a toy model for biological detectors that
captures their main characteristic, namely a detection threshold, we show that
Bell inequalities can be violated, thus demonstrating entanglement. Remarkably,
when the response function of the detector is close to a step function, quantum
non-locality can be demonstrated without any further assumptions. For smoother
response functions, as for the human eye, post-selection is required.


title: Detection of spin reversal and nutations through current measurements

abstract:
  The dynamics of a single spin embedded in a the tunnel junction between
ferromagnetic contacts is strongly affected by the exchange coupling to the
tunneling electrons. Moment reversal of the local spin induced by the bias
voltage across the junction is shown to have a measurable effect on the
tunneling current. Furthermore, the frequency of a harmonic bias voltage is
picked up by the local spin dynamics and transferred back to the current
generating a double frequency component.


title: Riesz transforms for the Dunkl harmonic oscillator

abstract:
  We define and investigate a system of Riesz transforms related to the Dunkl
harmonic oscillator.


title:
Generalized Helmholtz-Kirchhoff model for two dimensional distributed
  vortex motion

abstract:
  The two-dimensional Navier-Stokes equations are rewritten as a system of
coupled nonlinear ordinary differential equations. These equations describe the
evolution of the moments of an expansion of the vorticity with respect to
Hermite functions and of the centers of vorticity concentrations. We prove the
convergence of this expansion and show that in the zero viscosity and zero core
size limit we formally recover the Helmholtz-Kirchhoff model for the evolution
of point-vortices. The present expansion systematically incorporates the
effects of both viscosity and finite vortex core size. We also show that a
low-order truncation of our expansion leads to the representation of the flow
as a system of interacting Gaussian (i.e. Oseen) vortices which previous
experimental work has shown to be an accurate approximation to many important
physical flows [9].


title: Complex Interpolation between Hilbert, Banach and Operator spaces

abstract:
  Motivated by a question of Vincent Lafforgue, we study the Banach spaces $X$
satisfying the following property: there is a function $\vp\to \Delta_X(\vp)$
tending to zero with $\vp>0$ such that every operator $T\colon L_2\to L_2$ with
$\|T\|\le \vp$ that is simultaneously contractive (i.e. of norm $\le 1$) on
$L_1$ and on $L_\infty$ must be of norm $\le \Delta_X(\vp)$ on $L_2(X)$.
  We show that $\Delta_X(\vp)\in O(\vp^\alpha)$ for some $\alpha>0$ iff $X$ is
isomorphic to a quotient of a subspace of an ultraproduct of
$\theta$-Hilbertian spaces for some $ \theta>0$ (see Corollary
\ref{comcor4.3}), where $\theta$-Hilbertian is meant in a slightly more general
sense than in our previous paper \cite{P1}. Let $B_{r}(L_2(\mu))$ be the space
of all regular operators on $L_2(\mu)$. We are able to describe the complex
interpolation space \[ (B_{r}(L_2(\mu), B(L_2(\mu))^\theta. \] We show that
$T\colon L_2(\mu)\to L_2(\mu)$ belongs to this space iff $T\otimes id_X$ is
bounded on $L_2(X)$ for any $\theta$-Hilbertian space $X$.
  More generally, we are able to describe the spaces $$ (B(\ell_{p_0}),
B(\ell_{p_1}))^\theta {\rm or} (B(L_{p_0}), B(L_{p_1}))^\theta $$ for any pair
$1\le p_0,p_1\le \infty$ and $0<\theta<1$. In the same vein, given a locally
compact Abelian group $G$, let $M(G)$ (resp. $PM(G)$) be the space of complex
measures (resp. pseudo-measures) on $G$ equipped with the usual norm
$\|\mu\|_{M(G)} = |\mu|(G)$ (resp. \[ \|\mu\|_{PM(G)} = \sup\{|\hat\mu(\gamma)|
  \big| \gamma\in\hat G\}). \] We describe similarly the interpolation space
$(M(G), PM(G))^\theta$. Various extensions and variants of this result will be
given, e.g. to Schur multipliers on $B(\ell_2)$ and to operator spaces.


title: On a recent generalization of semiperfect rings

abstract:
  It follows from a recent paper by Ding and Wang that any ring which is
generalized supplemented as left module over itself is semiperfect. The purpose
of this note is to show that Ding and Wang's claim is not true and that the
class of generalized supplemented rings lies properly between the class of
semilocal and semiperfect rings. Moreover we rectify their claim by introducing
a wider notion of local submodules.


title:
Localization Theory in Zero Dimension and the Structure of Diffusion
  Poles

abstract:
  The 1/[-i\omega + D(\omega, q)q^2] diffusion pole in the localized phase
transfers to the 1/\omega Berezinskii-Gorkov singularity, which can be analyzed
by the instanton method (M V. Sadovskii, 1982; J. L. Cardy, 1978).
Straightforward use of this approach leads to contradictions, which do not
disappear even if the problem is extremely simplied by taking zero-dimensional
limit. On the contrary, they are extremely sharpened in this case and become
paradoxes. The main paradox is specified by the following statements: (i) the
1/\omega singularity is determined by high orders of perturbation theory, (ii)
the high-order behaviors for two quantities \Phi^{RA} and U^{RA} are the same,
and (iii) \Phi^{RA} has the 1/\omega singularity, whereas U^{RA} does not have
it. Solution to the paradox indicates that the instanton method makes it
possible to obtain only the 1/(\omega + i\gamma) singularity, where the
parameter \gamma remains indefinite and must be determined from additional
conditions. This conceptually confirms the necessity of the self-consistent
treatment for the diffusion coefficient that is used in the Vollhardt-Wolfle
type theories.

categories: cond-mat.other cond-mat.mes-hall hep-ph hep-th


title: Towards Unifying Structures in Higher Spin Gauge Symmetry

abstract:
  This article is expository in nature, outlining some of the many still
incompletely understood features of higher spin field theory. We are mainly
considering higher spin gauge fields in their own right as free-standing
theoretical constructs and not circumstances where they occur as part of
another system. Considering the problem of introducing interactions among
higher spin gauge fields, there has historically been two broad avenues of
approach. One approach entails gauging a non-Abelian global symmetry algebra,
in the process making it local. The other approach entails deforming an already
local but Abelian gauge algebra, in the process making it non-Abelian. In cases
where both avenues have been explored, such as for spin 1 and 2 gauge fields,
the results agree (barring conceptual and technical issues) with Yang-Mills
theory and Einstein gravity. In the case of an infinite tower of higher spin
gauge fields, the first approach has been thoroughly developed and explored by
M. Vasiliev, whereas the second approach, after having lain dormant for a long
time, has received new attention by several authors lately. In the present
paper we briefly review some aspects of the history of higher spin gauge fields
as a backdrop to an attempt at comparing the gauging vs. deforming approaches.
A common unifying structure of strongly homotopy Lie algebras underlying both
approaches will be discussed. The modern deformation approach, using BRST-BV
methods, will be described as far as it is developed at the present time. The
first steps of a formulation in the categorical language of operads will be
outlined. A few aspects of the subject that seems not to have been thoroughly
investigated are pointed out.


title: Universal Window for Two Dimensional Critical Exponents

abstract:
  Two dimensional condensed matter is realised in increasingly diverse forms
that are accessible to experiment and of potential technological value. The
properties of these systems are influenced by many length scales and reflect
both generic physics and chemical detail. To unify their physical description
is therefore a complex and important challenge. Here we investigate the
distribution of experimentally estimated critical exponents, $\beta$, that
characterize the evolution of the order parameter through the ordering
transition. The distribution is found to be bimodal and bounded within a window
$\sim 0.1 \le \beta \le 0.25$, facts that are only in partial agreement with
the established theory of critical phenomena. In particular, the bounded nature
of the distribution is impossible to reconcile with existing theory for one of
the major universality classes of two dimensional behaviour - the XY model with
four fold crystal field - which predicts a spectrum of non-universal exponents
bounded only from below. Through a combination of numerical and renormalization
group arguments we resolve the contradiction between theory and experiment and
demonstrate how the "universal window" for critical exponents observed in
experiment arises from a competition between marginal operators.


title: Confirmation of a Faraday Rotation Measure Anomaly in Cygnus

abstract:
  We confirm the reality of a reversal of the sign of the Faraday Rotation
Measure in the Galactic plane in Cygnus (Lazio et al, 1990), possibly
associated with the Cygnus OB1 association. The rotation measure changes by
several hundred rad/m$^2$ over an angular scale of $2-5^{\circ}$. We show that
a simple model of an expanding plasma shell with an enhanced density and
magnetic field, consistent with observations of H$\alpha$ emission in this part
of sky, and physically associated with a superbubble of the Cygnus OB1
association, can account for the magnitude and angular scale of this feature.


title:
Symmetry Transformation in Extended Phase Space: the Harmonic Oscillator
  in the Husimi Representation

abstract:
  In a previous work the concept of quantum potential is generalized into
extended phase space (EPS) for a particle in linear and harmonic potentials. It
was shown there that in contrast to the Schr\"odinger quantum mechanics by an
appropriate extended canonical transformation one can obtain the Wigner
representation of phase space quantum mechanics in which the quantum potential
is removed from dynamical equation. In other words, one still has the form
invariance of the ordinary Hamilton-Jacobi equation in this representation. The
situation, mathematically, is similar to the disappearance of the centrifugal
potential in going from the spherical to the Cartesian coordinates. Here we
show that the Husimi representation is another possible representation where
the quantum potential for the harmonic potential disappears and the modified
Hamilton-Jacobi equation reduces to the familiar classical form. This happens
when the parameter in the Husimi transformation assumes a specific value
corresponding to $Q$-function.


title: Popularity, Novelty and Attention

abstract:
  We analyze the role that popularity and novelty play in attracting the
attention of users to dynamic websites. We do so by determining the performance
of three different strategies that can be utilized to maximize attention. The
first one prioritizes novelty while the second emphasizes popularity. A third
strategy looks myopically into the future and prioritizes stories that are
expected to generate the most clicks within the next few minutes. We show that
the first two strategies should be selected on the basis of the rate of novelty
decay, while the third strategy performs sub-optimally in most cases. We also
demonstrate that the relative performance of the first two strategies as a
function of the rate of novelty decay changes abruptly around a critical value,
resembling a phase transition in the physical world. 1


title: Silicon Resonant Antenna

abstract:
  The need for high data rate communication systems has been dramatically
increasing in recent years. The millimeter-wave bands (such as 60 GHz) have
been investigated for wireless high data rate transmission. At these
frequencies, the conductor loss is significant which makes dielectric resonator
antenna (DRA) a good replacement for microstrip patch antennas currently in
use. Moreover, use of silicon as the dielectric material in a DRA provides the
great feature of bandwidth tunability through carrier density modulation. In
this paper, we present experimental and theoretical studies of antennas made
from silicon.


title: Particle motion during the compaction of granular matter

abstract:
  We track particle motions in a granular material subjected to compaction
using a laser scattering based imaging method where compaction is achieved
through thermal cycling. Particle displacements in this jammed fluid correlate
strongly with rearrangments of the Voronoi cells defining the local spatial
partitioning about the particles, similar to previous observations of Rahman on
cooled liquids. Our observations provide further evidence of commonalities
between particle dynamics in granular matter close to jamming and supercooled
liquids.


title: Exact Solution to Ideal Chain with Fixed Angular Momentum

abstract:
  The statistical mechanics of a non-interacting polymer chain in the limit of
a large number of monomers is considered when the total angular momentum, L, is
fixed. The radius of gyration for a ring polymer in this situation is derived
exactly in closed form by functional integration techniques. Even when L = 0
the radius of gyration differs from that of a random walk by a prefactor of
order unity. The dependence on L is discussed qualitatively and the large L
limit can be understood by physical arguments.


title: Algorithmically independent sequences

abstract:
  Two objects are independent if they do not affect each other. Independence is
well-understood in classical information theory, but less in algorithmic
information theory. Working in the framework of algorithmic information theory,
the paper proposes two types of independence for arbitrary infinite binary
sequences and studies their properties. Our two proposed notions of
independence have some of the intuitive properties that one naturally expects.
For example, for every sequence $x$, the set of sequences that are independent
(in the weaker of the two senses) with $x$ has measure one. For both notions of
independence we investigate to what extent pairs of independent sequences, can
be effectively constructed via Turing reductions (from one or more input
sequences). In this respect, we prove several impossibility results. For
example, it is shown that there is no effective way of producing from an
arbitrary sequence with positive constructive Hausdorff dimension two sequences
that are independent (even in the weaker type of independence) and have
super-logarithmic complexity. Finally, a few conjectures and open questions are
discussed.


title: Reproducing spin lattice models in strongly coupled atom-cavity systems

abstract:
  In an array of coupled cavities where the cavities are doped with an atomic
V-system, and the two excited levels couple to cavity photons of different
polarizations, we show how to construct various spin models employed in
characterizing phenomena in condensed matter physics, such as the spin-1/2
Ising, XX, Heisenberg, and XXZ models. The ability to construct networks of
arbitrary geometry also allows for the simulation of topological effects. By
tuning the number of excitations present, the dimension of the spin to be
simulated can be controlled, and mixtures of different spin types produced. The
facility of single-site addressing, the use of only the natural hopping photon
dynamics without external fields, and the recent experimental advances towards
strong coupling, makes the prospect of using these arrays as efficient quantum
simulators promising.


title: Measuring the roughness of random paths by increment ratios

abstract:
  A statistic based on increment ratios (IR) and related to zero crossings of
increment sequence is defined and studied for measuring the roughness of random
paths. The main advantages of this statistic are robustness to smooth additive
and multiplicative trends and applicability to infinite variance processes. The
existence of the IR statistic limit (called the IR-roughness below) is closely
related to the existence of a tangent process. Three particular cases where the
IR-roughness exists and is explicitly computed are considered. Firstly, for a
diffusion process with smooth diffusion and drift coefficients, the
IR-roughness coincides with the IR-roughness of a Brownian motion and its
convergence rate is obtained. Secondly, the case of rough Gaussian processes is
studied in detail under general assumptions which do not require stationarity
conditions. Thirdly, the IR-roughness of a L\'evy process with $\alpha-$stable
tangent process is established and can be used to estimate the fractional
parameter $\alpha \in (0,2)$ following a central limit theorem.


title: Cosmological MHD simulation of a cooling flow cluster

abstract:
  Various observations of magnetic fields in the Intra-Cluster Medium (ICM),
most of the time restricted to cluster cores, point towards field strength of
the order of a few microG (synchrotron radiation from radio relics and radio
halos, inverse Compton radiation in X-rays and Faraday rotation measure of
polarised background sources). Both the origin and the spatial structure of
galaxy clusters magnetic fields are still under debate. In particular, the
radial profile of the magnetic field, from the core of clusters to their
outskirts, is of great importance for cosmic rays propagation within the Cosmic
Web. In this letter, we highlight the importance of cooling processes in
amplifying the magnetic field in the core of galaxy clusters up to one order of
magnitude above the typical amplification obtained for a pure adiabatic
evolution. We have performed a "zoom'' cosmological simulation of a 3 keV
cluster, including dark matter and gas dynamics, atomic cooling, UV heating and
star formation using the newly developed MHD solver in the AMR code RAMSES.
Magnetic field amplification proceeds mainly through gravitational contraction.
Shearing motions due to turbulence provide additional amplification in the
outskirts of the cluster, while magnetic reconnection during mergers causes
magnetic field dissipation in the core. Cooling processes have a strong impact
on the magnetic field structure in the cluster. First, due to the sharp rise of
the gas density in the centre, gravitational amplification is significantly
amplified, when compared to the non--radiative run. Second, due to cooling
processes, shearing motions are much stronger in the core than in the adiabatic
case, leading to additional field amplification and no significant magnetic
reconnection.


title: Duality Cascade in Brane Inflation

abstract:
  We show that brane inflation is very sensitive to tiny sharp features in
extra dimensions, including those in the potential and in the warp factor. This
can show up as observational signatures in the power spectrum and/or
non-Gaussianities of the cosmic microwave background radiation (CMBR). One
general example of such sharp features is a succession of small steps in a
warped throat, caused by Seiberg duality cascade using gauge/gravity duality.
We study the cosmological observational consequences of these steps in brane
inflation. Since the steps come in a series, the prediction of other steps and
their properties can be tested by future data and analysis. It is also possible
that the steps are too close to be resolved in the power spectrum, in which
case they may show up only in the non-Gaussianity of the CMB temperature
fluctuations and/or EE polarization. We study two cases. In the slow-roll
scenario where steps appear in the inflaton potential, the sensitivity of brane
inflation to the height and width of the steps is increased by several orders
of magnitude comparing to that in previously studied large field models. In the
IR DBI scenario where steps appear in the warp factor, we find that the
glitches in the power spectrum caused by these sharp features are generally
small or even unobservable, but associated distinctive non-Gaussianity can be
large. Together with its large negative running of the power spectrum index,
this scenario clearly illustrates how rich and different a brane inflationary
scenario can be when compared to generic slow-roll inflation. Such distinctive
stringy features may provide a powerful probe of superstring theory.


title:
On the Detectability of Oxygen X-ray Fluorescence and its Use as a Solar
  Photospheric Abundance Diagnostic

abstract:
  Monte Carlo calculations of the O Kalpha line fluoresced by coronal X-rays
and emitted just above the temperature minimum region of the solar atmosphere
have been employed to investigate the use of this feature as an abundance
diagnostic. While quite weak, we estimate line equivalent widths in the range
0.02-0.2 AA, depending on the X-ray plasma temperature. The line remains
essentially uncontaminated by blends for coronal temperatures T =< 3e6 K and
should be quite observable, with a flux >~ 2 ph/s/arcmin^2. Model calculations
for solar chemical mixtures with an O abundance adjusted up and down by a
factor of 2 indicate 35-60% changes in O Kalpha line equivalent width,
providing a potentially useful O abundance diagnostic. Sensitivity of
equivalent width to differences between recently recommended chemical
compositions with ``high'' and ``low'' complements of the CNO trio important
for interpreting helioseismological observations is less accute, amounting to
20-26% at coronal temperatures T ~< 2e6 K. While still feasible for
discriminating between these two mixtures, uncertainties in measured line
equivalent widths and in the models used for interpretation would need to be
significantly less than 20%. Provided a sensitive X-ray spectrometer with
resolving power >= 1000 and suitably well-behaved instrumental profile can be
built, X-ray fluorescence presents a viable means for resolving the solar
``oxygen crisis''.


title:
An X-ray Survey of Wolf-Rayet Stars in the Magellanic Clouds. II. The
  ROSAT PSPC and HRI Datasets

abstract:
  Wolf-Rayet (WR) stars in the Magellanic Clouds (MCs) are ideal for studying
the production of X-ray emission by their strong fast stellar winds. We have
started a systematic survey for X-ray emission from WR stars in the MCs using
archival Chandra, ROSAT, and XMM-Newton observations. In Paper I, we reported
the detection of X-ray emission from 29 WR stars using Chandra ACIS
observations of 70 WR stars in the MCs. In this paper, we report the search and
analysis of archival ROSAT PSPC and HRI observations of WR stars. While useful
ROSAT observations are available for 117 WR stars in the MCs, X-ray emission is
detected from only 7 of them. The detection rate of X-ray emission from MCs WR
stars in the ROSAT survey is much smaller than in the Chandra ACIS survey,
illustrating the necessity of high angular resolution and sensitivity. LMC-WR
101-102 and 116 were detected by both ROSAT and Chandra, but no large long-term
variations are evident.


title: The magnetar 1E 1547.0-5408: radio spectrum, polarimetry, and timing

abstract:
  We have investigated the radio emission from the anomalous X-ray pulsar 1E
1547.0-5408 (PSR J1550-5418) using the Parkes telescope and the Australia
Telescope Compact Array. The flux density of the pulsar is roughly the same
between 1.4 and 45 GHz, but shows time variability. The radiation is nearly
100% linearly polarized between frequencies of 45 and 3.2 GHz, but from 2.3 to
1.4 GHz it becomes increasingly more depolarized. The rotation measure of -1860
rad/m^2 is the largest for any known pulsar, and implies an average magnetic
field strength along the line of sight of 2.7 microG. The pulse profiles are
circularly polarized at all frequencies observed, more so at lower frequencies,
at the ~15% level. The observed swing of the position angle of linear
polarization as a function of pulse phase suggests that in this neutron star
the rotation and magnetic axes are nearly aligned, and that its radio emission
is only detectable within a small solid angle. Timing measurements indicate
that the period derivative of this 2 s pulsar has increased by nearly 40% in a
6-month period. The flat spectrum and variability in flux density and pulse
profiles are reminiscent of the properties of XTE J1810-197, the only other
known radio-emitting magnetar, and are anomalous by comparison with those of
ordinary radio pulsars.


title: Barred Galaxies: an Observer's Perspective

abstract:
  I review both well established and more recent findings on the properties of
bars, and their host galaxies, stemming from photometric and spectroscopic
observations, and discuss how these findings can be understood in terms of a
global picture of the formation and evolution of bars, keeping a connection
with theoretical developments. In particular, I show the results of a detailed
structural analysis of ~ 300 barred galaxies in the Sloan Digital Sky Survey,
providing physical quantities, such as bar length, ellipticity and boxyness,
and bar-to-total luminosity ratio, that can either be used as a solid basis on
which realistic models can be built, or be compared against more fundamental
theoretical results. I also show correlations that indicate that bars grow
longer, thinner and stronger with dynamical age, and that the growth of bars
and bulges is connected. Finally, I briefly discuss open questions and possible
directions for future research.


title: Accretion of gas onto nearby spiral galaxies

abstract:
  We present evidence for cosmological gas accretion onto spiral galaxies in
the local universe. The accretion is seen through its effects on the dynamics
of the extra-planar neutral gas. The accretion rates that we estimate for two
nearby spiral galaxies are of the order of their star formation rates. Our
model shows that most of the extra-planar gas is produced by supernova feedback
(galactic fountain) and only 10-20 % comes from accretion. The accreting
material must have low specific angular momentum about the disc's spin axis,
although the magnitude of the specific angular-momentum vector can be higher.
We also explore the effects of a hot corona on the dynamics of the extra-planar
gas and find that it is unlikely to be responsible for the observed kinematical
pattern and the source of accreted gas. However, the interaction with the
fountain flow should profoundly affect the hydrodynamics of the corona.


title:
The SCUBA HAlf Degree Extragalactic Survey (SHADES) - VII. Optical/IR
  photometry and stellar masses of sub-millimeter galaxies

abstract:
  We present estimates of the photometric redshifts, stellar masses and star
formation histories of sources in the SCUBA HAlf Degree Extragalactic Survey
(SHADES). This paper describes the 60 SCUBA sources detected in the Lockman
Hole covering an area of ~320 square arcmin. Using photometry spanning the B
band to 8um, we find that the average SCUBA source forms a significant fraction
of its stars in an early period of star formation and that most of the
remainder forms in a shorter more intense burst around the redshift it is
observed. This trend does not vary significantly with source redshift but the
exact ratio of early to late mass is quite sensitive to the way extinction is
treated in the modelling. However, the sources show a clear increase in stellar
mass with redshift, consistent with downsizing. In terms of SED types, only two
out of the 51 sources we have obtained photometric redshifts for are best fit
by a quasar-like spectral energy distribution, with approximately 80 per cent
of the sources being best fit with late-type spectra (Sc, Im and starburst). By
including photometry at 850um, we conclude that the average SCUBA source is
forming stars at a rate somewhere between 6 and 30 times the rate implied from
the rest-frame optical in a dust obscured burst and that this burst creates
15-65 per cent of the total stellar mass. Using a simplistic calculation, we
estimate from the average star formation history that between one in five and
one in 15 bright (L_* +2 mag < L_optical < L_* -1 mag) galaxies in the field
over the interval 0 < z < 3 will at some point in their lifetime experience a
similar energetic dusty burst of star formation. Finally, we compute the
evolution of the star formation rate density and find it peaks around z=2.


title:
Experimental design and model selection: The example of exoplanet
  detection

abstract:
  We apply the Minimum Description Length model selection approach to the
detection of extra-solar planets, and use this example to show how
specification of the experimental design affects the prior distribution on the
model parameter space and hence the posterior likelihood which, in turn,
determines which model is regarded as most `correct'. Our analysis shows how
conditioning on the experimental design can render a non-compact parameter
space effectively compact, so that the MDL model selection problem becomes
well-defined.


title:
A deep Chandra observation of Abell 4059: a new face to radio-mode AGN
  feedback?

abstract:
  A deep Chandra observation of the cooling core cluster Abell 4059 (A4059) is
presented. Previous studies have found two X-ray cavities in the central
regions of A4059 together with a ridge of X-ray emission 20kpc south-west of
the cluster center. These features are clearly related to the radio galaxy
PKS2354-35 which resides in the cD galaxy. Our new data confirm these previous
findings and strengthen previous suggestions that the south-western ridge is
colder and denser than, but in approximate pressure equilibrium with, the
surrounding ICM atmosphere. In addition, we find evidence for a weak shock that
wraps around the north and east sides of the cavity structure. Our data allow
us to map the 2-dimensional distribution of metals in the ICM of A4059 for the
first time. We find that the SW ridge possesses an anomalously high
(super-solar) metalicity. The unusual morphology, temperature structure and
metal distribution all point to significant asymmetry in the ICM atmosphere
prior to the onset of radio-galaxy activity. Motivated by the very high
metalicity of the SW ridge, we hypothesize that the ICM asymmetry was caused by
the extremely rapid stripping of metal enriched gas from a starburst galaxy
that plunged through the core of A4059. Furthermore, we suggest that the onset
of powerful radio-galaxy activity in the cD galaxy may have been initiated by
this starburst/stripping event, either via the tidal-shocking of cold gas
native to the cD galaxy, or the accretion of cold gas that had been stripped
from the starburst galaxy.


title:
Deconfined quantum criticality driven by Dirac fermions in SU(2)
  antiferromagnets

abstract:
  Quantum electrodynamics in 2+1 dimensions is an effective gauge theory for
the so called algebraic quantum liquids. A new type of such a liquid, the
algebraic charge liquid, has been proposed recently in the context of
deconfined quantum critical points [R. K. Kaul {\it et al.}, Nature Physics
{\bf 4}, 28 (2008)]. In this context, we show by using the renormalization
group in $d=4-\epsilon$ spacetime dimensions, that a deconfined quantum
critical point occurs in a SU(2) system provided the number of Dirac fermion
species $N_f\geq 4$. The calculations are done in a representation where the
Dirac fermions are given by four-component spinors. The critical exponents are
calculated for several values of $N_f$. In particular, for $N_f=4$ and
$\epsilon=1$ ($d=2+1$) the anomalous dimension of the N\'eel field is given by
$\eta_N=1/3$, with a correlation length exponent $\nu=1/2$. These values change
considerably for $N_f>4$. For instance, for $N_f=6$ we find $\eta_N\approx
0.75191$ and $\nu\approx 0.66009$. We also investigate the effect of chiral
symmetry breaking and analyze the scaling behavior of the chiral holon
susceptibility, $G_\chi(x)\equiv<\bar \psi(x)\psi(x)\bar \psi(0)\psi(0)>$.


title: An extended star cluster at the outer edge of the spiral galaxy M33

abstract:
  We report a discovery of an extended globular-like star cluster, M33-EC1, at
the outer edge of the spiral galaxy M33. The distance to the cluster is 890
kpc, and it lies at a 12.5 kpc projected distance from the center of M33. Old
age (>~7 Gyr) and low metallicity ([M/H] <~ -1.4) are estimated on the basis of
isochrone fits. Color-magnitude diagrams of stars, located in the cluster's
area, photometric and structural parameters of the cluster are presented.
Cluster's luminosity (M_V = -6.6) and half-light radius (r_h = 20.3 pc) are
comparable to those of the extended globular clusters, discovered in more
luminous Local Group galaxies, the Milky Way and M31. Extended globular
clusters are suspected to be remnants of accreted dwarf galaxies, and the
finding of such a cluster in the late-type dwarf spiral galaxy M33 would imply
a complex merging history in the past.


title:
Fredholm equations for non-symmetric kernels, with applications to
  iterated integral operators

abstract:
  We give the Jordan form and the Singular Value Decomposition for an integral
operator ${\cal N}$ with a non-symmetric kernel $N(y,z)$. This is used to give
solutions of Fredholm equations for non-symmetric kernels, and to determine the
behaviour of ${\cal N}^n$ and $({\cal N}{\cal N^*})^n$ for large $n$.


title:
An X-ray Survey of Wolf-Rayet Stars in the Magellanic Clouds. I. The
  Chandra ACIS Dataset

abstract:
  Wolf-Rayet (WR) stars are evolved massive stars with strong fast stellar
winds. WR stars in our Galaxy have shown three possible sources of X-ray
emission associated with their winds: shocks in the winds, colliding stellar
winds, and wind-blown bubbles; however, quantitative analyses of observations
are often hampered by uncertainties in distances and heavy foreground
absorption. These problems are mitigated in the Magellanic Clouds (MCs), which
are at known distances and have small foreground and internal extinction. We
have therefore started a survey of X-ray emission associated with WR stars in
the MCs using archival Chandra, ROSAT, and XMM-Newton observations. In the
first paper of this series, we report the results for 70 WR stars in the MCs
using 192 archival Chandra ACIS observations. X-ray emission is detected from
29 WR stars. We have investigated their X-ray spectral properties,
luminosities, and temporal variability. These X-ray sources all have
luminosities greater than a few times 10^32 ergs s^-1, with spectra indicative
of highly absorbed emission from a thin plasma at high temperatures typical of
colliding winds in WR+OB binary systems. Significant X-ray variability with
periods ranging from a few hours up to ~20 days is seen associated with several
WR stars. In most of these cases, the X-ray variability can be linked to the
orbital motion of the WR star in a binary system, further supporting the
colliding wind scenario for the origin of the X-ray emission from these stars.


title:
Experimental Studies of Compensation of Beam-Beam Effects with Tevatron
  Electron Lenses

abstract:
  Applying the space-charge forces of a low-energy electron beam can lead to a
significant improvement of the beam-particle lifetime limit arising from the
beam-beam interaction in a high-energy collider [1]. In this article we present
the results of various beam experiments with electron lenses, novel instruments
developed for the beam-beam compensation at the Tevatron, which collides
980-GeV proton and antiproton beams. We study the dependencies of the particle
betatron tunes on the electron beam current, energy and position; we explore
the effects of electron-beam imperfections and noises; and we quantify the
improvements of the high-energy beam intensity and the collider luminosity
lifetime obtained by the action of the Tevatron Electron Lenses.


title: How to constrain inflationary parameter space with minimal priors

abstract:
  We update constraints on the Hubble function H(phi) during inflation, using
the most recent cosmic microwave background (CMB) and large scale structure
(LSS) data. Our main focus is on a comparison between various commonly used
methods of calculating the primordial power spectrum via analytical
approximations and the results obtained by integrating the exact equations
numerically. In each case, we impose naive, minimally restrictive priors on the
duration of inflation. We find that the choice of priors has an impact on the
results: the bounds on inflationary parameters can vary by up to a factor two.
Nevertheless, it should be noted that within the region allowed by the minimal
prior of the exact method, the accuracy of the approximations is sufficient for
current data. We caution however that a careless minimal implementation of the
approximative methods allows models for which the assumptions behind the
analytical approximations fail, and recommend using the exact numerical method
for a self-consistent analysis of cosmological data.


title: Lightest U-parity Particle (LUP) dark matter

abstract:
  We suggest a U(1)' gauge symmetry as an alternative to the usual R-parity of
supersymmetric standard models, showing that it can also work as a common
source of stabilities of proton and dark matter in addition to other attractive
features. The residual discrete symmetries of a single U(1)' can provide
stabilities to both the MSSM sector (proton) and the hidden sector (new dark
matter candidate, LUP). The LUP can expand the viability of many models such as
R-parity violating models and gauge mediation models regarding dark matter
issue.


title:
An Ultraluminous Supersoft X-ray Source in M81: An Intermediate-Mass
  Black Hole?

abstract:
  Ultraluminous supersoft X-ray sources (ULSSS) exhibit supersoft spectra with
blackbody temperatures of 50-100 eV and bolometric luminosities above $10^{39}$
erg s$^{-1}$, and are possibly intermediate mass black holes (IMBHs) of
$\ge10^3 M_\odot$ or massive white dwarfs that are progenitors of type Ia
supernovae. In this letter we report our optical studies of such a source in
M81, M81-ULS1, with HST archive observations. M81-ULS1 is identified with a
point-like object, the spectral energy distribution of which reveals a blue
component in addition to the companion of an AGB star. The blue component is
consistent with the power-law as expected from the geometrically-thin accretion
disk around an IMBH accretor, but inconsistent with the power-law as expected
from the X-ray irradiated flared accretion disk around a white dwarf accretor.
This result is strong evidence that M81-ULS1 is an IMBH instead of a white
dwarf.


title:
Dissipation and Extra Light in Galactic Nuclei: I. Gas-Rich Merger
  Remnants

abstract:
  We study the origin and properties of 'extra' or 'excess' central light in
the surface brightness profiles of gas-rich merger remnants. Combining a large
set of hydrodynamical simulations with data on observed mergers (spanning a
broad range of profiles at various masses and degrees of relaxation), we show
how to robustly separate the physically meaningful extra light -- stellar
populations formed in a compact central starburst during a gas-rich merger --
from the outer profile established by violent relaxation acting on stars
already present in the progenitors prior to the final merger. This separation
is sensitive to the profile treatment, and we demonstrate that certain fitting
procedures can yield physically misleading results. We show that our method
reliably recovers the younger starburst population, and examine how the
properties of this component scale with mass, gas content, and other aspects of
the progenitors. We consider the time evolution of profiles in different bands,
and estimate biases introduced by observational studies at different times and
wavelengths. We show that extra light is ubiquitous in observed and simulated
gas-rich merger remnants, with sufficient mass (~3-30% of the stellar mass) to
explain the discrepancy in the maximum phase-space densities of ellipticals and
their progenitor spirals. The nature of this central component provides
powerful new constraints on the formation histories of observed systems.


title: Causal Models for Estimating the Effects of Weight Gain on Mortality

abstract:
  Suppose, contrary to fact, in 1950, we had put the cohort of 18 year old
non-smoking American men on a stringent mandatory diet that guaranteed that no
one would ever weigh more than their baseline weight established at age 18. How
would the counter-factual mortality of these 18 year olds have compared to
their actual observed mortality through 2007? We describe in detail how this
counterfactual contrast could be estimated from longitudinal epidemiologic data
similiar to that stored in the electronic medical records of a large HMO by
applying g-estimation to a novel structural nested model. Our analytic approach
differs from any alternative approach in that in that, in the abscence of model
misspecification, it can successfully adjust for (i) measured time-varying
confounders such as exercise, hypertension and diabetes that are simultaneously
intermediate variables on the causal pathway from weight gain to death and
determinants of future weight gain, (ii) unmeasured confounding by undiagnosed
preclinical disease (i.e reverse causation) that can cause both poor weight
gain and premature mortality [provided an upper bound can be specified for the
maximum length of time a subject may suffer from a subclinical illness severe
enough to affect his weight without the illness becomes clinically manifest],
and (iii) the prescence of particular identifiable subgroups, such as those
suffering from serious renal, liver, pulmonary, and/or cardiac disease, in whom
confounding by unmeasured prognostic factors so severe as to render useless any
attempt at direct analytic adjustment.


title: A guide to telescopic functors

abstract:
  In the mid 1980's, Pete Bousfield and I constructed certain p--local
`telescopic' functors Phi_n from spaces to spectra, for each prime p and each
positive integer n. These have striking properties that relate the chromatic
approach to homotopy theory to infinite loopspace theory: roughly put, the
spectrum Phi_n(Z) captures the v_n periodic homotopy of a space Z.
  Recently there have been a variety of new uses of these functors, suggesting
that they have a central role to play in calculations of periodic phenomena.
Here I offer a guide to their construction, characterization, application, and
computation.


title:
Microstructure-based modeling of elastic functionally graded materials:
  One dimensional case

abstract:
  Functionally graded materials (FGMs) are two-phase composites with
continuously changing microstructure adapted to performance requirements.
Traditionally, the overall behavior of FGMs has been determined using local
averaging techniques or a given smooth variation of material properties.
Although these models are computationally efficient, their validity and
accuracy remain questionable, since a link with the underlying microstructure
(including its randomness) is not clear. In this paper, we propose a modeling
strategy for the linear elastic analysis of FGMs systematically based on a
realistic microstructural model. The overall response of FGMs is addressed in
the framework of stochastic Hashin-Shtrikman variational principles. To allow
for the analysis of finite bodies, recently introduced discretization schemes
based on the Finite Element Method and the Boundary Element Method are employed
to obtain statistics of local fields. Representative numerical examples are
presented to compare the performance and accuracy of both schemes. To gain
insight into similarities and differences between these methods and to minimize
technicalities, the analysis is performed in the one-dimensional setting.


title:
Connected components of the compactification of representation spaces of
  surface groups

abstract:
  The Thurston compactification of Teichmuller spaces has been generalized to
many different representation spaces by J. Morgan, P. Shalen, M. Bestvina, F.
Paulin, A. Parreau and others. In the simplest case of representations of
fundamental groups of closed hyperbolic surfaces in PSL(2,R), we prove that
this compactification is very degenerated: the nice behaviour of the Thurston
compactification of the Teichmuller space contrasts with wild phenomena
happening on the boundary of the other connected components of these
representation spaces. We prove that it is more natural to consider a
refinement of this compactification, which remembers the orientation of the
hyperbolic plane. The ideal points of this compactification are fat R-trees,
i.e., R-trees equipped with a planar structure.


title: Black holes and core expansion in massive star clusters

abstract:
  We present the results from realistic N-body modelling of massive star
clusters in the Magellanic Clouds. We have computed eight simulations with N ~
10^5 particles; six of these were evolved for at least a Hubble time. The aim
of this modelling is to examine the possibility of large-scale core expansion
in massive star clusters and search for a viable dynamical origin for the
radius-age trend observed for such objects in the Magellanic Clouds. We
identify two physical processes which can lead to significant and prolonged
cluster core expansion: mass-loss due to rapid stellar evolution in a
primordially mass segregated cluster, and heating due to a retained population
of stellar-mass black holes. These two processes operate over different
time-scales - the former occurs only at early times and cannot drive core
expansion for longer than a few hundred Myr, while the latter typically does
not begin until several hundred Myr have passed but can result in core
expansion lasting for many Gyr. We investigate the behaviour of these expansion
mechanisms in clusters with varying degrees of primordial mass segregation and
in clusters with varying black hole retention fractions. In combination, the
two processes can lead to a wide variety of evolutionary paths on the
radius-age plane, which fully cover the observed cluster distribution and hence
define a dynamical origin for the radius-age trend in the Magellanic Clouds. We
discuss the implications of core expansion for various aspects of globular
cluster research, as well as the possibility of observationally inferring the
presence of a population of stellar-mass black holes in a cluster.


title: AdS/CFT and Light-Front QCD

abstract:
  The AdS/CFT correspondence between string theory in AdS space and conformal
field theories in physical space-time leads to an analytic, semi-classical
model for strongly-coupled QCD which has scale invariance and dimensional
counting at short distances and color confinement at large distances. The
AdS/CFT correspondence also provides insights into the inherently
nonperturbative aspects of QCD such as the orbital and radial spectra of
hadrons and the form of hadronic wavefunctions. In particular, we show that
there is an exact correspondence between the fifth-dimensional coordinate of
AdS space $z$ and a specific impact variable $\zeta$ which measures the
separation of the quark and gluonic constituents within the hadron in ordinary
space-time. This connection leads to AdS/CFT predictions for the analytic form
of the frame-independent light-front wavefunctions (LFWFs) of mesons and
baryons, the fundamental entities which encode hadron properties. The LFWFs in
turn predict decay constants and spin correlations, as well as dynamical
quantities such as form factors, structure functions, generalized parton
distributions, and exclusive scattering amplitudes. Relativistic light-front
equations in ordinary space-time are found which reproduce the results obtained
using the fifth-dimensional theory and have remarkable algebraic structures and
integrability properties. As specific examples we describe the behavior of the
pion form factor in the space and time-like regions and determine the Dirac
nucleon form factors in the space-like region. An extension to nonzero quark
mass is used to determine hadronic distribution amplitudes of all mesons, heavy
and light. We compare our results with the moments of the distribution
amplitudes which have recently been computed from lattice gauge theory.


title: Double-blind test program for astrometric planet detection with Gaia

abstract:
  We use detailed simulations of the Gaia observations of synthetic planetary
systems and develop and utilize independent software codes in double-blind mode
to analyze the data, including statistical tools for planet detection and
different algorithms for single and multiple Keplerian orbit fitting that use
no a priori knowledge of the true orbital parameters of the systems. 1) Planets
with astrometric signatures $\alpha\simeq 3$ times the single-measurement error
$\sigma_\psi$ and period $P\leq 5$ yr can be detected reliably, with a very
small number of false positives. 2) At twice the detection limit, uncertainties
in orbital parameters and masses are typically $15%-20%$. 3) Over 70% of
two-planet systems with well-separated periods in the range $0.2\leq P\leq 9$
yr, $2\leq\alpha/\sigma_\psi\leq 50$, and eccentricity $e\leq 0.6$ are
correctly identified. 4) Favorable orbital configurations have orbital elements
measured to better than 10% accuracy $> 90%$ of the time, and the value of the
mutual inclination angle determined with uncertainties $\leq 10^{\degr}$. 5)
Finally, uncertainties obtained from the fitting procedures are a good estimate
of the actual errors. Extrapolating from the present-day statistical properties
of the exoplanet sample, the results imply that a Gaia with $\sigma_\psi$ = 8
$\mu$as, in its unbiased and complete magnitude-limited census of planetary
systems, will measure several thousand giant planets out to 3-4 AUs from stars
within 200 pc, and will characterize hundreds of multiple-planet systems,
including meaningful coplanarity tests. Finally, we put Gaia into context,
identifying several areas of planetary-system science in which Gaia can be
expected to have a relevant impact, when combined with data coming from other
ongoing and future planet search programs.


title:
Fundamental Quantum Limit to Multiphoton Absorption Rate for
  Monochromatic Light

abstract:
  The local multiphoton absorption rate for an arbitrary quantum state of
monochromatic light, taking into account the photon number, momentum, and
polarization degrees of freedom, is shown to have an upper bound that can be
reached by coherent fields. This surprising result rules out any quantum
enhancement of the multiphoton absorption rate by momentum entanglement.


title:
Probing the role of single defects on the thermodynamics of
  electric-field induced phase transitions

abstract:
  The kinetics and thermodynamics of first order transitions is universally
controlled by defects that act as nucleation sites and pinning centers. Here we
demonstrate that defect-domain interactions during polarization reversal
processes in ferroelectric materials result in a pronounced fine structure in
electromechanical hysteresis loops. Spatially-resolved imaging of a single
defect center in multiferroic BiFeO3 thin film is achieved, and the defect size
and built-in field are determined self-consistently from the single-point
spectroscopic measurements and spatially-resolved images. This methodology is
universal and can be applied to other reversible bias-induced transitions
including electrochemical reactions.


title:
Velocity Structure in the Orion Nebula. II. Emission Line Atlas of
  Partially Ionized to Fully Ionized Gas

abstract:
  We present an atlas of three-dimensional (position-position-velocity) spectra
of the Orion Nebula in optical emission lines from a variety of different
ionization stages: [O I] 6300, [S II] 6716,6731, [N II] 6584, [S III] 6312, H
alpha 6563, and [O III] 5007. These transitions provide point to point
information about the physical structure and kinematics of the nebula at an
effective resolution of 3'' x 2'' x 10 km/s, clearly showing the large scale
behavior of the ionized gas and the presence of localized phenomena such as
Herbig-Haro outflows. As an example application of the atlas, we present a
statistical analysis of the widths of the H alpha, [O III], and [N II] lines
that permits a determination of the mean electron temperature in the nebula of
(9200 +/- 400) K. We also find, in contradiction to previous claims, that the
non-thermal line broadening is not significantly different between
recombination lines and collisional lines.


title: Black Holes in Higher-Dimensional Gravity

abstract:
  These lectures review some of the recent progress in uncovering the phase
structure of black hole solutions in higher-dimensional vacuum Einstein
gravity. The two classes on which we focus are Kaluza-Klein black holes, i.e.
static solutions with an event horizon in asymptotically flat spaces with
compact directions, and stationary solutions with an event horizon in
asymptotically flat space. Highlights include the recently constructed
multi-black hole configurations on the cylinder and thin rotating black rings
in dimensions higher than five. The phase diagram that is emerging for each of
the two classes will be discussed, including an intriguing connection that
relates the phase structure of Kaluza-Klein black holes with that of
asymptotically flat rotating black holes.


title:
Multifractal analysis of Birkhoff averages on "self-affine" symbolic
  spaces

abstract:
  We achieve on self-affine Sierpinski carpets the multifractal analysis of the
Birkhoff averages of potentials satisfying a Dini condition. Given such a
potential, the corresponding Hausdorff spectrum cannot be deduced from that of
the associated Gibbs measure by a simple transformation. Indeed, these spectra
are respectively obtained as the Legendre transform of two distinct concave
differentiable functions that cannot be deduced from one another by a dilation
and a translation. This situation is in contrast with what is observed in the
familiar self-similar case. Our results are presented in the framework of
almost-multiplicative functions on products of two distinct symbolic spaces and
their projection on the associated self-affine carpets.


title: Aether Compactification

abstract:
  We propose a new way to hide extra dimensions without invoking branes, based
on Lorentz-violating tensor fields with expectation values along the extra
directions. We investigate the case of a single vector ``aether'' field on a
compact circle. In such a background, interactions of other fields with the
aether can lead to modified dispersion relations, increasing the mass of the
Kaluza-Klein excitations. The mass scale characterizing each Kaluza-Klein tower
can be chosen independently for each species of scalar, fermion, or gauge
boson. No small-scale deviations from the inverse square law for gravity are
predicted, although light graviton modes may exist.


title: Potential for modulation of the hydrophobic effect inside chaperonins

abstract:
  Despite the spontaneity of some in vitro protein folding reactions, native
folding in vivo often requires the participation of barrel-shaped multimeric
complexes known as chaperonins. Although it has long been known that chaperonin
substrates fold upon sequestration inside the chaperonin barrel, the precise
mechanism by which confinement within this space facilitates folding remains
unknown. In this study, we examine the possibility that the chaperonin mediates
a favorable reorganization of the solvent for the folding reaction. We begin by
discussing the effect of electrostatic charge on solvent-mediated hydrophobic
forces in an aqueous environment. Based on these initial physical arguments, we
construct a simple, phenomenological theory for the thermodynamics of density
and hydrogen bond order fluctuations in liquid water. Within the framework of
this model, we investigate the effect of confinement within a chaperonin-like
cavity on the configurational free energy of water by calculating solvent free
energies for cavities corresponding to the different conformational states in
the ATP- driven catalytic cycle of the prokaryotic chaperonin GroEL. Our
findings suggest that one function of chaperonins may be to trap unfolded
proteins and subsequently expose them to a micro-environment in which the
hydrophobic effect, a crucial thermodynamic driving force for folding, is
enhanced.


title:
The distribution of the maximum of a first order moving average: the
  continuous case

abstract:
  We give the distribution of $M_n$, the maximum of a sequence of $n$
observations from a moving average of order 1. Solutions are first given in
terms of repeated integrals and then for the case where the underlying
independent random variables have an absolutely continuous density. When the
correlation is positive, $$ P(M_n %\max^n_{i=1} X_i \leq x) =\
\sum_{j=1}^\infty \beta_{jx} \nu_{jx}^{n} \approx B_{x} \nu_{1x}^{n} $$ where
%$\{X_i\}$ is a moving average of order 1 with positive correlation, and
$\{\nu_{jx}\}$ are the eigenvalues (singular values) of a Fredholm kernel and
$\nu_{1x}$ is the eigenvalue of maximum magnitude. A similar result is given
when the correlation is negative. The result is analogous to large deviations
expansions for estimates, since the maximum need not be standardized to have a
limit. % there are more terms, and $$P(M_n <x) \approx B'_{x}\
(1+\nu_{1x})^n.$$
  For the continuous case the integral equations for the left and right
eigenfunctions are converted to first order linear differential equations. The
eigenvalues satisfy an equation of the form $$\sum_{i=1}^\infty
w_i(\lambda-\theta_i)^{-1}=\lambda-\theta_0$$ for certain known weights
$\{w_i\}$ and eigenvalues $\{\theta_i\}$ of a given matrix. This can be solved
by truncating the sum to an increasing number of terms.


title:
A generating function for the N-soliton solutions of the
  Kadomtsev-Petviashvili II equation

abstract:
  This work describes a classification of the $N$-soliton solutions of the
Kadomtsev-Petviashvili II equation in terms of chord diagrams of N chords
joining pairs of 2N points. The different classes of N-solitons are enumerated
by the distribution of crossings of the chords. The generating function of the
chord diagrams is expressed as a continued fraction, special cases of which are
moment generating functions for certain kinds of $q$-orthogonal polynomials.


title: New D-term chaotic inflation in supergravity and leptogenesis

abstract:
  We present a new model of D-term dominated chaotic inflation in supergravity.
The F-flat direction present in this model is lifted by the dominant D-term,
which leads to chaotic inflation and subsequent reheating. No cosmic string is
formed after inflation because the U(1) gauge symmetry is broken during
inflation. The leptogenesis scenario via the inflaton decay in our D-term
chaotic inflation scenario is also discussed.


title: Impurity in a granular gas under nonlinear Couette flow

abstract:
  We study in this work the transport properties of an impurity immersed in a
granular gas under stationary nonlinear Couette flow. The starting point is a
kinetic model for low-density granular mixtures recently proposed by the
authors [Vega Reyes F et al. 2007 Phys. Rev. E 75 061306]. Two routes have been
considered. First, a hydrodynamic or normal solution is found by exploiting a
formal mapping between the kinetic equations for the gas particles and for the
impurity. We show that the transport properties of the impurity are
characterized by the ratio between the temperatures of the impurity and gas
particles and by five generalized transport coefficients: three related to the
momentum flux (a nonlinear shear viscosity and two normal stress differences)
and two related to the heat flux (a nonlinear thermal conductivity and a cross
coefficient measuring a component of the heat flux orthogonal to the thermal
gradient). Second, by means of a Monte Carlo simulation method we numerically
solve the kinetic equations and show that our hydrodynamic solution is valid in
the bulk of the fluid when realistic boundary conditions are used. Furthermore,
the hydrodynamic solution applies to arbitrarily (inside the continuum regime)
large values of the shear rate, of the inelasticity, and of the rest of
parameters of the system. Preliminary simulation results of the true Boltzmann
description show the reliability of the nonlinear hydrodynamic solution of the
kinetic model. This shows again the validity of a hydrodynamic description for
granular flows, even under extreme conditions, beyond the Navier-Stokes domain.


title:
Conservative Properties of the Variational Free-Lagrange Method for
  Shallow Water

abstract:
  The variational free-Lagrange (VFL) method for shallow water is a
free-Lagrange method with the additional property that it preserves the
variational structure of shallow water. The VFL method was first derived in
this context by \cite{AUG84} who discretized Hamilton's action principle with a
free-Lagrange data structure. The purpose of this article is to assess the
long-time conservation properties of the VFL method for regularized shallow
water which are useful for climate simulation. Long-time regularized shallow
water simulations show that the VFL method exhibits no secular drift in the (i)
energy error through the application of symplectic integrators; and (ii) the
potential vorticity error through the construction of discrete curl, divergence
and gradient operators which satisfy semi-discrete divergence and potential
vorticity conservation laws. These diagnostic semi-discrete equations augment
the description of the VFL method by characterizing the evolution of its
respective irrotational and solenoidal components in the Lagrangian frame. Like
the continuum equations, the former exhibits a $\text{div}^2\mathbf{U}$ term
which indicates that the flow has a very strong tendency towards a purely
rotational state.
  Numerical results show (i) the preservation of shape and strength of an
initially radially symmetric vortex pair in purely rotational regularized
shallow water and (ii) how the Voronoi diagram retains the history of the flow
field and (iii) that energy is conserved to $\mathcal{O}(\Delta^2)$ and
potential vorticity error to within 5% with no secular growth over a 50 year
period.


title: Routh's procedure for non-Abelian symmetry groups

abstract:
  We extend Routh's reduction procedure to an arbitrary Lagrangian system (that
is, one whose Lagrangian is not necessarily the difference of kinetic and
potential energies) with a symmetry group which is not necessarily Abelian. To
do so we analyse the restriction of the Euler-Lagrange field to a level set of
momentum in velocity phase space. We present a new method of analysis based on
the use of quasi-velocities. We discuss the reconstruction of solutions of the
full Euler-Lagrange equations from those of the reduced equations.


title:
The distribution of the maximum of a first order moving average: the
  discrete case

abstract:
  We give the distribution of $M_n$, the maximum of a sequence of $n$
observations from a moving average of order 1. Solutions are first given in
terms of repeated integrals and then for the case where the underlying
independent random variables are discrete. When the correlation is positive, $$
P(M_n \max^n_{i=1} X_i \leq x) = \sum_{j=1}^\infty \beta_{jx} \nu_{jx}^{n}
\approx B_{x} r{1x}^{n} $$ where $\{\nu_{jx}\}$ are the eigenvalues of a
certain matrix, $r_{1x}$ is the maximum magnitude of the eigenvalues, and $I$
depends on the number of possible values of the underlying random variables.
The eigenvalues do not depend on $x$ only on its range.


title: Bonnor stars in d spacetime dimensions

abstract:
  Bonnor stars are regular static compact configurations in equilibrium,
composed of an extremal dust fluid, a charged dust fluid where the mass density
is equal to the charge density, joined to an exterior vacuum solution, within
Newtonian gravity and general relativity. In four dimensions, they obey the
corresponding Majumdar-Papapetrou system, where the gravitational potential is
a simple function of the electric potential field and the fluid, when there is
one, is made of extremal dust. The Majumdar-Papapetrou system can be
generalized to d spacetime dimensions. Thus, it is natural to study Bonnor
solutions in higher d dimensions. We analyze Newton-Coulomb theory with an
electrically charged fluid in a Majumdar-Papapetrou context, in d=n+1 spacetime
dimensions, n the number of spatial dimensions. Within the Newtonian theory, in
vacuum, the Majumdar-Papapetrou relation for the gravitational potential in
terms of the electric potential, and its related Weyl relation, are equivalent,
in contrast with general relativity. We study a class of spherically symmetric
Bonnor stars. Under sufficient compactification they form point mass charged
Newtonian singularities. We study the analogue systems in the Einstein-Maxwell
theory with an electrically charged fluid. We restate some properties of this
system and obtain spherically symmetric Bonnor star solutions in d=n+1
spacetime dimensions. These stars, under compactification, form quasi-black
holes. Whereas there are no solutions for Newtonian or relativistic stars
supported by degenerate pressure in higher dimensions, higher dimensional
Bonnor stars, supported by electric repulsion, do indeed have solutions within
Newtonian gravity and general relativity. So the existence of stars depends on
the number of dimensions and on the underlying field content.


title: Observing solar-like oscillations

abstract:
  The past few years have seen great progress in observing oscillations in
solar-type stars, lying on or just above the main sequence. We review the most
recent results, most of which were obtained using high-precision velocity
measurements. We also briefly discuss observations of more evolved stars,
namely G, K and M giants and supergiants.


title:
Trigonometric Solutions of WDVV Equations and Generalized
  Calogero-Moser-Sutherland Systems

abstract:
  We consider trigonometric solutions of WDVV equations and derive geometric
conditions when a collection of vectors with multiplicities determines such a
solution. We incorporate these conditions into the notion of trigonometric
Veselov system ($\vee$-system) and we determine all trigonometric
$\vee$-systems with up to five vectors. We show that generalized
Calogero-Moser-Sutherland operator admits a factorized eigenfunction if and
only if it corresponds to the trigonometric $\vee$-system; this inverts a
one-way implication observed by Veselov for the rational solutions.


title: Sobolev and Schwartz: Two Fates and Two Fames

abstract:
  This is a brief overview of the lives and contributions of S.L. Sobolev and
L. Schwartz, the cofounders of distribution theory.


title:
Capacity of Wireless Networks within o(log(SNR)) - the Impact of Relays,
  Feedback, Cooperation and Full-Duplex Operation

abstract:
  Recent work has characterized the sum capacity of
time-varying/frequency-selective wireless interference networks and $X$
networks within $o(\log({SNR}))$, i.e., with an accuracy approaching 100% at
high SNR (signal to noise power ratio). In this paper, we seek similar capacity
characterizations for wireless networks with relays, feedback, full duplex
operation, and transmitter/receiver cooperation through noisy channels. First,
we consider a network with $S$ source nodes, $R$ relay nodes and $D$
destination nodes with random time-varying/frequency-selective channel
coefficients and global channel knowledge at all nodes. We allow full-duplex
operation at all nodes, as well as causal noise-free feedback of all received
signals to all source and relay nodes. The sum capacity of this network is
characterized as $\frac{SD}{S+D-1}\log({SNR})+o(\log({SNR}))$. The implication
of the result is that the capacity benefits of relays, causal feedback,
transmitter/receiver cooperation through physical channels and full duplex
operation become a negligible fraction of the network capacity at high SNR.
Some exceptions to this result are also pointed out in the paper. Second, we
consider a network with $K$ full duplex nodes with an independent message from
every node to every other node in the network. We find that the sum capacity of
this network is bounded below by $\frac{K(K-1)}{2K-2}+o(\log({SNR}))$ and
bounded above by $\frac{K(K-1)}{2K-3}+o(\log({SNR}))$.


title: Finite Volume Kolmogorov-Johnson-Mehl-Avrami Theory

abstract:
  We study Kolmogorov-Johnson-Mehl-Avrami (KJMA) theory of phase conversion in
finite volumes. For the conversion time we find the relationship $\tau_{\rm
con} = \tau_{\rm nu} [1+f_d(q)]$. Here $d$ is the space dimension, $\tau_{\rm
nu}$ the nucleation time in the volume $V$, and $f_d(q)$ a scaling function.
Its dimensionless argument is $q=\tau_{\rm ex}/ \tau_{\rm nu}$, where
$\tau_{\rm ex}$ is an expansion time, defined to be proportional to the
diameter of the volume divided by expansion speed. We calculate $f_d(q)$ in
one, two and three dimensions. The often considered limits of phase conversion
via either nucleation or spinodal decomposition are found to be volume-size
dependent concepts, governed by simple power laws for $f_d(q)$.


title:
On the Asymptotic Normality of the Conditional Maximum Likelihood
  Estimators for the Truncated Regression Model and the Tobit Model

abstract:
  In this paper, we study the asymptotic normality of the conditional maximum
likelihood (ML) estimators for the truncated regression model and the Tobit
model. We show that under the general setting assumed in his book, the
conjectures made by Hayashi (2000) \footnote{see page 516, and page 520 of
Hayashi (2000).} about the asymptotic normality of the conditional ML
estimators for both models are true, namely, a sufficient condition is the
nonsingularity of $\mathbf{x_tx'_t}$.


title:
Support Vector Machines and Kd-tree for Separating Quasars from Large
  Survey Databases

abstract:
  We compare the performance of two automated classification algorithms:
k-dimensional tree (kd-tree) and support vector machines (SVMs), to separate
quasars from stars in the databases of the Sloan Digital Sky Survey (SDSS) and
the Two Micron All Sky Survey (2MASS) catalogs. The two algorithms are trained
on subsets of SDSS and 2MASS objects whose nature is known via spectroscopy. We
choose different attribute combination as input patterns to train the
classifier using photometric data only and present the classification results
obtained by these two methods. Performance metrics such as precision and
recall, true positive rate and true negative rate, F-measure, G-mean and
Weighted Accuracy are computed to evaluate the performance of the two
algorithms. The study shows that both kd-tree and SVMs are effective automated
algorithms to classify point sources. SVMs show slightly higher accuracy, but
kd-tree requires less computation time. Given different input patterns based on
various parameters(e.g. magnitudes, color information), we conclude that both
kd-tree and SVMs show better performance with fewer features. What is more, our
results also indicate that the accuracy using the four colors (u-g, g-r, r-i,
i-z) and r magnitude based on SDSS model magnitudes adds up to the highest
value. The classifiers trained by kd-tree and SVMs can be used to solve the
automated classification problems faced by the virtual observatory (VO);
moreover, they all can be applied for the photometric preselection of quasar
candidates for large survey projects in order to optimize the efficiency of
telescopes.


title: PKS B1545-321: Bow shocks of a relativistic jet?

abstract:
  Sensitive, high resolution images of the double-double radio galaxy PKS
B1545-321 reveal detailed structure, which we interpret in the light of
previous work on the interaction of restarted jets with pre-existing relict
cocoons. We have also examined the spectral and polarization properties of the
source, the color distribution in the optical host and the environment of this
galaxy in order to understand its physical evolution. We propose that the
restarted jets generate narrow bow shocks and that the inner lobes are a
mixture of cocoon plasma reaccelerated at the bow shock and new jet material
reaccelerated at the termination shock. The dynamics of the restarted jets
implies that their hot spots advance at mildly relativistic speeds with
external Mach numbers of at least 5. The existence of supersonic hot spot Mach
numbers and bright inner lobes is the result of entrainment causing a reduction
in the sound speed of the pre-existing cocoon. The interruption to jet activity
in PKS B1545-321 has been brief - lasting less than a few percent of the
lifetime $\sim (0.3-2)\times 10^{8} yr$ of the giant radio source. The host
galaxy is located at the boundary of a large scale filamentary structure, and
shows blue patches in color distribution indicative of a recent merger, which
may have triggered the Mpc-scale radio galaxy.


title:
Optical Absorption of Poly(thiophene vinylene) Conjugated Polymers.
  Experiment and First Principle Theory

abstract:
  Optical absorption spectra of poly(thiophene vinylene) (PTV) conjugated
polymers have been studied at room temperature in the spectral range of 450 to
800 nm. A dominant peak located at 577 nm and a prominent shoulder at 619 nm
are observed. Another shoulder located at 685 nm is observed at high
concentration and after additional treatment (heat, sonification) only.
Equilibrium atomic geometries and optical absorption of PTV conjugated polymers
have also been studied by first principles density functional theory (DFT). For
PTV in solvent, the theoretical calculations predict two equilibrium geometries
with different interchain distances. By comparative analysis of the
experimental and theoretical data, it is demonstrated that the new measured
long-wavelength optical absorption shoulder is consistent with new optical
absorption peak predicted for most energetically favorable PTV phase in the
solvent. This shoulder is interpreted as a direct indication of increased
interchain interaction in the solvent which has caused additional electronic
energy structure transformations.


title: VSOP Observations of the Blazar S5 2007+77

abstract:
  The blazar, S5 2007+77 shows intraday variability in cm wavelengths. Seven
epochs of VSOP observations were carried out in 1998 and 1999 at 5 GHz to look
for the origin of the variability with the highest achievable angular
resolution at cm wavelengths. Here the results of four epochs are analysed,
which revealed ~10% variations in polarized flux density.


title:
Dynamical Shakeup of Planetary Systems II. N-body simulations of Solar
  System terrestrial planet formation induced by secular resonance sweeping

abstract:
  We revisit the "dynamical shakeup" model of Solar System terrestrial planet
formation, wherein the whole process is driven by the sweeping of Jupiter's
secular resonance as the gas disk is removed. Using a large number of 0.5
Gyr-long N-body simulations, we investigate the different outcomes produced by
such a scenario. We confirm that in contrast to existing models, secular
resonance sweeping combined with tidal damping by the disk gas can reproduce
the low eccentricities and inclinations, and high radial mass concentration, of
the Solar System terrestrial planets. At the same time, this also drives the
final assemblage of the planets on a timescale of several tens of millions of
years, an order of magnitude faster than inferred from previous numerical
simulations which neglected these effects, but possibly in better agreement
with timescales inferred from cosmochemical data. In addition, we find that
significant delivery of water-rich material from the outer Asteroid Belt is a
natural byproduct.


title:
Entropy of (1+1)-dimensional charged black hole to all orders in the
  Planck length

abstract:
  We study the statistical entropy of a scalar field on the (1+1)-dimensional
Maxwell-dilaton background without an artificial cutoff considering corrections
to all orders in the Planck length from a generalized uncertainty principle
(GUP) on the quantum state density. In contrast to the previous results of the
higher dimensional cases having adjustable parameter, we obtain an unadjustable
entropy due to the independence of the minimal length while this entropy is
proportional to the Bekenstein-Hawking entropy.


title:
Improving Performance of Cluster Based Routing Protocol using
  Cross-Layer Design

abstract:
  The main goal of routing protocol is to efficiency delivers data from source
to destination. All routing protocols are the same in this goal, but the way
they adopt to achieve it is different, so routing strategy has an egregious
role on the performance of an ad hoc network. Most of routing protocols
proposed for ad hoc networks have a flat structure. These protocols expand the
control overhead packets to discover or maintain a route. On the other hand a
number of hierarchical-based routing protocols have been developed, mostly are
based on layered design. These protocols improve network performances
especially when the network size grows up since details about remote portion of
network can be handled in an aggregate manner. Although, there is another
approach to design a protocol called cross-layer design. Using this approach
information can exchange between different layer of protocol stack, result in
optimizing network performances.
  In this paper, we intend to exert cross-layer design to optimize Cluster
Based Routing Protocol (Cross-CBRP). Using NS-2 network simulator we evaluate
rate of cluster head changes, throughput and packet delivery ratio. Comparisons
denote that Cross-CBRP has better performances with respect to the original
CBRP.