title: Interpolation in Valiant's theory

abstract:
  We investigate the following question: if a polynomial can be evaluated at
rational points by a polynomial-time boolean algorithm, does it have a
polynomial-size arithmetic circuit? We argue that this question is certainly
difficult. Answering it negatively would indeed imply that the constant-free
versions of the algebraic complexity classes VP and VNP defined by Valiant are
different. Answering this question positively would imply a transfer theorem
from boolean to algebraic complexity. Our proof method relies on Lagrange
interpolation and on recent results connecting the (boolean) counting hierarchy
to algebraic complexity classes. As a byproduct we obtain two additional
results: (i) The constant-free, degree-unbounded version of Valiant's
hypothesis that VP and VNP differ implies the degree-bounded version. This
result was previously known to hold for fields of positive characteristic only.
(ii) If exponential sums of easy to compute polynomials can be computed
efficiently, then the same is true of exponential products. We point out an
application of this result to the P=NP problem in the Blum-Shub-Smale model of
computation over the field of complex numbers.


title: Monolithic Pixels R&D at LBNL

abstract:
  This paper reports recent results from the ongoing R&D on monolithic pixels
for the ILC Vertex Tracker at LBNL.


title: Spontaneous P-parity violation in dense baryon matter

abstract:
  We investigate possibilities for dynamical P-parity violation in dense baryon
matter in the framework of effective quark models. Dynamical P-parity violation
can appear in models with at least two scalar and two pseudoscalar fields,
where both scalar fields are condensed at normal conditions. At special
configurations of coupling constants, one of pseudoscalar fields can then also
condense at some value of baryon density, the phenomenon results in mixing of
the scalar and pseudoscalar physical degrees of freedom, hence, giving rise to
P-parity violation. We discuss the implications and possible experimental
signatures for P-parity violation in strong interactions in future experiments
with heavy-ion collisions.


title: Central limits and homogenization in random media

abstract:
  We consider the perturbation of elliptic operators of the form
  $P(\bx,\bD)$ by random, rapidly varying, sufficiently mixing, potentials of
the form $q(\frac{\bx}\eps,\omega)$. We analyze the source and spectral
problems associated to such operators and show that the properly renormalized
difference between the perturbed and unperturbed solutions may be written
asymptotically as $\eps\to0$ as explicit Gaussian processes. Such results may
be seen as central limit corrections to the homogenization (law of large
numbers) process. Similar results are derived for more general elliptic
equations in one dimension of space. The results are based on the availability
of a rapidly converging integral formulation for the perturbed solutions and on
the use of classical central limit results for random processes with
appropriate mixing conditions.


title:
Modified Gravity: Cosmology without dark matter or Einstein's
  cosmological constant

abstract:
  We explore the cosmological consequences of Modified Gravity (MOG), and find
that it provides, using a minimal number of parameters, good fits to data,
including CMB temperature anisotropy, galaxy power spectrum, and supernova
luminosity-distance observations without exotic dark matter. MOG predicts a
bouncing cosmology with a vacuum energy term that yields accelerating expansion
and an age of ~13 billion years.


title:
Large oscillating non-local voltage in multi-terminal single wall carbon
  nanotube devices

abstract:
  We report on the observation of a non-local voltage in a ballistic
one-dimensional conductor, realized by a single-wall carbon nanotube with four
contacts. The contacts divide the tube into three quantum dots which we control
by the back-gate voltage $V_g$. We measure a large \emph{oscillating} non-local
voltage $V_{nl}$ as a function of $V_g$ with zero mean. Though a classical
resistor model can account for a non-local voltage including change of sign, it
fails to describe the magnitude properly. The large amplitude of $V_{nl}$ is
due to quantum interference effects and can be understood within the
scattering-approach of electron transport.


title:
Coupling constant constraints in a nonminimally coupled phantom
  cosmology

abstract:
  In the paper we investigate observational constraints on coupling to gravity
constant parameter $\xi$ using distant supernovae SNIa data, baryon oscillation
peak (BOP), the cosmic microwave background radiation (CMBR) shift parameter,
and $H(z)$ data set. We estimate the value of this parameter to constrain the
extended quintessence models with nonminimally coupled to gravity phantom
scalar field. The combined analysis of observational data favors a value of
$\xi$ which lies in close neighborhood of the conformal coupling. While our
estimations are model dependent they give rise to a indirect bound on the
Equivalence Principle.


title:
Discovery of an X-ray nebula around PSR J1718-3825 and implications for
  the nature of the gamma-ray source HESS J1718-385

abstract:
  Combined X-ray synchrotron and inverse-Compton gamma-ray observations of
pulsar wind nebulae (PWN) may help to elucidate the processes of acceleration
and energy loss in these systems. In particular, such observations provide
constraints on the particle injection history and the magnetic field strength
in these objects. The newly discovered TeV gamma-ray source HESS J1718-385 has
been proposed as the likely PWN of the high spin-down luminosity pulsar PSR
J1718-3825. The absence of previous sensitive X-ray measurements of this
pulsar, and the unusual energy spectrum of the TeV source, motivated
observations of this region with XMM-Newton. The data obtained reveal a hard
spectrum X-ray source at the position of PSR 1718-3825 and evidence for diffuse
emission in the vicinity of the pulsar. We derive limits on the keV emission
from the centroid of HESS J1718-385 and discuss the implications of these
findings for the PWN nature of this object.


title:
The electronic bands of CrD, CrH, MgD and MgH: application to the
  "deuterium test"

abstract:
  We compute opacities for the electronic molecular band systems A 6Sigma+ -- X
6Sigma+ of CrH and CrD, and A 2Pi -- X 2Sigma+ of MgH and MgD. The opacities
are computed by making use of existing spectroscopic constants for MgH and CrH.
These constants are adjusted for the different reduced masses of MgD and CrD.
Frank-Condon factors are used to provide intensities for the individual
vibronic bands. These results are used in the computation of synthetic spectra
between Tef = 1800 and 1200 K with an emphasis on the realisation of
``deuterium test'', first proposed by Bejar et al. (1999) to distinguish brown
dwarfs from planetary mass objects. We discuss the possible use of CrD and MgD
electronic bands for the "deuterium test". We find CrD to be the more promising
of the two deuterides, potentially, the most useful bands of CrH/CrD are the
Delta v = +1 and Delta v = -1 at 0.795 and 0.968 micron.


title:
Thermodynamics of Ion Solvation and Differential Adsorption at
  Liquid-Liquid Interfaces and Membranes

abstract:
  We construct a mean-field formulation of the thermodynamics of ion solvation
in immiscible polar binary mixtures. Assuming an equilibrium planar interface
separating two semi-infinite regions of different constant dielectric medium,
we study the electrostatic phenomenon of differential adsorption of ions at the
interface. Using general thermodynamic considerations, we construct the
mean-field $\Omega$-potential and demonstrate the spontaneous formation of an
electric double-layer around the interface necessarily follow. In our
framework, we can also relate both the bulk ion densities in the two phases and
the distribution potential across the interface to the fundamental Born free
energy of ion polarization. We further illustrate this selective ion adsorption
phenomenon in respective examples of fully permeable membranes that are
neutral, negative, or positive in charge polarity.


title:
MegaPipe: the MegaCam image stacking pipeline at the Canadian
  Astronomical Data Centre

abstract:
  This paper describes the MegaPipe image processing pipeline at the Canadian
Astronomical Data Centre. The pipeline combines multiple images from the
MegaCam mosaic camera on CFHT and combines them into a single output image.
MegaPipe takes as input detrended MegaCam images and does a careful astrometric
and photometric calibration on them. The calibrated images are then resampled
and combined into image stacks. The astrometric calibration of the output
images is accurate to within 0.15 arcseconds relative to external reference
frames and 0.04 arcseconds internally. The photometric calibration is good to
within 0.03 magnitudes. The stacked images and catalogues derived from these
images are available through the CADC website:


title: Lyman-alpha Damping Wing Constraints on Inhomogeneous Reionization

abstract:
  One well-known way to constrain the hydrogen neutral fraction, x_H, of the
high-redshift intergalactic medium (IGM) is through the shape of the red
damping wing of the Lya absorption line. We examine this method's effectiveness
in light of recent models showing that the IGM neutral fraction is highly
inhomogeneous on large scales during reionization. Using both analytic models
and "semi-numeric" simulations, we show that the "picket-fence" absorption
typical in reionization models introduces both scatter and a systematic bias to
the measurement of x_H. In particular, we show that simple fits to the damping
wing tend to overestimate the true neutral fraction in a partially ionized
universe, with a fractional error of ~ 30% near the middle of reionization.
This bias is generic to any inhomogeneous model. However, the bias is reduced
and can even underestimate x_H if the observational sample only probes a subset
of the entire halo population, such as quasars with large HII regions. We also
find that the damping wing absorption profile is generally steeper than one
would naively expect in a homogeneously ionized universe. The profile steepens
and the sightline-to-sightline scatter increases as reionization progresses. Of
course, the bias and scatter also depend on x_H and so can, at least in
principle, be used to constrain it. Damping wing constraints must therefore be
interpreted by comparison to theoretical models of inhomogeneous reionization.


title:
The Revealing Dust: Mid-Infrared Activity in Hickson Compact Group
  Galaxy Nuclei

abstract:
  We present a sample of 46 galaxy nuclei from 12 nearby (z<4500 km/s) Hickson
Compact Groups (HCGs) with a complete suite of 1-24 micron 2MASS+Spitzer
nuclear photometry. For all objects in the sample, blue emission from stellar
photospheres dominates in the near-IR through the 3.6 micron IRAC band.
Twenty-five of 46 (54%) galaxy nuclei show red, mid-IR continua characteristic
of hot dust powered by ongoing star formation and/or accretion onto a central
black hole. We introduce alpha_{IRAC}, the spectral index of a power-law fit to
the 4.5-8.0 micron IRAC data, and demonstrate that it cleanly separates the
mid-IR active and non-active HCG nuclei. This parameter is more powerful for
identifying low to moderate-luminosity mid-IR activity than other measures
which include data at rest-frame lambda<3.6 micron that may be dominated by
stellar photospheric emission. While the HCG galaxies clearly have a bimodal
distribution in this parameter space, a comparison sample from the Spitzer
Nearby Galaxy Survey (SINGS) matched in J-band total galaxy luminosity is
continuously distributed. A second diagnostic, the fraction of 24 micron
emission in excess of that expected from quiescent galaxies, f_{24D}, reveals
an additional 3 nuclei to be active at 24 micron. Comparing these two mid-IR
diagnostics of nuclear activity to optical spectroscopic identifications from
the literature reveals some discrepancies, and we discuss the challenges of
distinguishing the source of ionizing radiation in these and other lower
luminosity systems. We find a significant correlation between the fraction of
mid-IR active galaxies and the total HI mass in a group, and investigate
possible interpretations of these results in light of galaxy evolution in the
highly interactive system of a compact group environment.


title: To Bin or Not To Bin: Decorrelating the Cosmic Equation of State

abstract:
  The physics behind the acceleration of the cosmic expansion can be elucidated
through comparison of the predictions of dark energy equations of state to
observational data. In seeking to optimize this, we investigate the advantages
and disadvantages of using principal component analysis, uncorrelated
bandpowers, and the equation of state within redshift bins. We demonstrate that
no one technique is a panacea, with tension between clear physical
interpretation from localization and from decorrelated errors, as well as model
dependence and form dependence. Specific lessons include the critical role of
proper treatment of the high redshift expansion history and the lack of a
unique, well defined signal-to-noise or figure of merit.


title: A chiral cascade via backreacting D7-branes with flux

abstract:
  In the context of AdS/CFT, we consider a cascading theory with an arbitrarily
large number of chiral flavors. In the UV the theory can be considered as a
chiral flavoring of the Klebanov-Tseytlin solution, and exhibits a duality
wall. Instead in the IR, due to the rich dynamics, it safely flows to a
non-cascading theory. We engineer the field theory through intersecting
D7-branes with world-volume gauge flux on a conifold with 3-form fluxes, and we
find new fully backreacted solutions of Type IIB Supergravity plus branes. We
match the field theory cascade with supergravity by computing Page charges and
interpreting Seiberg dualities as large gauge transformations of the
background. Eventually we give an interpretation of the chiral zero modes
arising at the intersection of the D7-branes with flux.


title:
Spider Optimization: Probing the Systematics of a Large Scale B-Mode
  Experiment

abstract:
  Spider is a long-duration, balloon-borne polarimeter designed to measure
large scale Cosmic Microwave Background (CMB) polarization with very high
sensitivity and control of systematics. The instrument will map over half the
sky with degree angular resolution in I, Q and U Stokes parameters, in four
frequency bands from 96 to 275 GHz. Spider's ultimate goal is to detect the
primordial gravity wave signal imprinted on the CMB B-mode polarization. One of
the challenges in achieving this goal is the minimization of the contamination
of B-modes by systematic effects. This paper explores a number of instrument
systematics and observing strategies in order to optimize B-mode sensitivity.
This is done by injecting realistic-amplitude, time-varying systematics in a
set of simulated time-streams. Tests of the impact of detector noise
characteristics, pointing jitter, payload pendulations, polarization angle
offsets, beam systematics and receiver gain drifts are shown. Spider's default
observing strategy is to spin continuously in azimuth, with polarization
modulation achieved by either a rapidly spinning half-wave plate or a rapidly
spinning gondola and a slowly stepped half-wave plate. Although the latter is
more susceptible to systematics, results shown here indicate that either mode
of operation can be used by Spider.


title:
Equivalence of QCD in the epsilon-regime and chiral Random Matrix Theory
  with or without chemical potential

abstract:
  We prove that QCD in the epsilon-regime of chiral Perturbation Theory is
equivalent to chiral Random Matrix Theory for zero and both non-zero real and
imaginary chemical potential mu. To this aim we prove a theorem that relates
integrals over fermionic and bosonic variables to super-Hermitian or
super-Unitary groups also called superbosonization. Our findings extend
previous results for the equivalence of the partition functions, spectral
densities and the quenched two-point densities. We can show that all k-point
density correlation functions agree in both theories for an arbitrary number of
quark flavors, for either mu=0 or mu=/=0 taking real or imaginary values. This
implies the equivalence for all individual k-th eigenvalue distributions which
are particularly useful to determine low energy constants from Lattice QCD with
chiral fermions.


title:
Idempotent and tropical mathematics and problems of mathematical physics
  (Volume I)

abstract:
  This volume contains the proceedings of an International Workshop on
Idempotent and Tropical Mathematics and Problems of Mathematical Physics, held
at the Independent University of Moscow, Russia, on August 25-30, 2007.

categories: math.RA math-ph math.AG math.AP math.MP math.OA math.OC math.RT


title: Inflated planets and their low-mass companions

abstract:
  Various mechanisms have been proposed to explain the inflated size of HD
209458b after it became clear that it has no companions capable of producing a
stellar reflex velocity greater than around 5 m/s. Had there been such a
companion, the hypothesis that it forces the eccentricity of the inflated
planet thereby tidally heating it may have been readily accepted. Here we
summarize a paper by the author which shows that companion planets with masses
as low as a fraction of an Earth mass are capable of sustaining a non-zero
eccentricity in the observed planet for at least the age of the system. While
such companions produce stellar reflex velocities which are fractions of a
meter per second and hence are below the stellar jitter limit, they are
consistent with recent theoretical work which suggests that the planet
migration process often produces low-mass companions to short-period giants.


title:
Consistent estimates of deformed isotropic Gaussian random fields on the
  plane

abstract:
  This paper proves fixed domain asymptotic results for estimating a smooth
invertible transformation $f:\Bbb{R}^2\to\Bbb{R}^2$ when observing the deformed
random field $Z\circ f$ on a dense grid in a bounded, simply connected domain
$\Omega$, where $Z$ is assumed to be an isotropic Gaussian random field on
$\Bbb{R}^2$. The estimate $\hat{f}$ is constructed on a simply connected domain
$U$, such that $\overline{U}\subset\Omega$ and is defined using kernel smoothed
quadratic variations, Bergman projections and results from quasiconformal
theory. We show, under mild assumptions on the random field $Z$ and the
deformation $f$, that $\hat{f}\to R_{\theta}f+c$ uniformly on compact subsets
of $U$ with probability one as the grid spacing goes to zero, where
$R_{\theta}$ is an unidentifiable rotation and $c$ is an unidentifiable
translation.


title: Fluctuations of particle ratios as a freeze-out probe

abstract:
  We explain how event-by-event fluctuations of particle ratios can constrain
and falsify the statistical model of particle production in heavy ion
collisions, using $K/\pi$ fluctuations as an example. We define an observable
capable of determining which statistical model, if any, governs freeze-out in
ultrarelativistic heavy ion collisions. We calculate this observable for
$K/\pi$ fluctuations, and show that it should be the same for RHIC and LHC
energies, as well as independent of centrality, if the Grand-Canonical
statistical model is an appropriate description and chemical equilibrium
applies. We describe what happens in case of deviations from this scenario,
such as light quark chemical non-equilibrium, strange quark over-saturation and
local conservation (canonical ensemble) for strange quarks. We also introduce a
similar observable capable, together with the published $K^*/K$ measurement, of
ascertaining if an interacting hadron gas phase governs the system between
thermal and chemical freeze-out, and of ascertaining its duration and impact on
hadronic chemistry


title:
The galaxy stellar mass-star formation rate relation: Evidence for an
  evolving stellar initial mass function?

abstract:
  The evolution of the galaxy stellar mass--star formation rate relationship
(M*-SFR) provides key constraints on the stellar mass assembly histories of
galaxies. For star-forming galaxies, M*-SFR is observed to be fairly tight with
a slope close to unity from z~0-2. Simulations of galaxy formation reproduce
these trends owing to the generic dominance of smooth and steady cold accretion
in these systems. In contrast, the amplitude of the M*-SFR relation evolves
markedly differently than in models. Stated in terms of a star formation
activity parameter alpha=(M*/SFR)/(t_H-1 Gyr), models predict a constant
alpha~1 out to redshifts z=4+, while the observed M*-SFR relation indicates
that alpha increases by X3 from z~2 until today. The low alpha at high-z not
only conflicts with models, but is also difficult to reconcile with other
observations of high-z galaxies. Systematic biases could significantly affect
measurements of M* and SFR, but detailed considerations suggest that none are
obvious candidates to reconcile the discrepancy. A speculative solution is
considered in which the stellar initial mass function (IMF) evolves towards
more high-mass star formation at earlier epochs. Following Larson, a model is
investigated in which the characteristic mass Mhat where the IMF turns over
increases with redshift. The observed and predicted M*-SFR evolution may be
brought into agreement if Mhat=0.5(1+z)^2 Mo out to z~2. Such evolution broadly
matches recent observations of cosmic stellar mass growth, and the resulting
z=0 cumulative IMF is similar to the paunchy IMF favored by Fardal et al to
reconcile the observed cosmic star formation history with present-day fossil
light measures. [abridged]


title:
The Suzaku Observation of NGC 3516: Complex Absorption and the Broad and
  Narrow Fe K Lines

abstract:
  We present results from a 150 ksec Suzaku observation of the Seyfert 1.5 NGC
3516 in October 2005. The source was in a relatively highly absorbed state. Our
best-fit model is consistent with the presence of a low-ionization absorber
which has a column density near 5 * 10^{22} cm^{-2} and covers most of the
X-ray continuum source (covering fraction 96-100%). A high-ionization absorbing
component, which yields a narrow absorption feature consistent with Fe K XXVI,
is confirmed. A relativistically broadened Fe K alpha line is required in all
fits, even after the complex absorption is taken into account; an additional
partial-covering component is an inadequate substitute for the continuum
curvature associated with the broad Fe line. A narrow Fe K alpha emission line
has a velocity width consistent with the Broad Line Region. The low-ionization
absorber may be responsible for producing the narrow Fe K alpha line, though a
contribution from additional material out of the line of sight is possible. We
include in our model soft band emission lines from He- and H-like ions of N, O,
Ne and Mg, consistent with photo-ionization, though a small contribution from
collisionally-ionized emission is possible.


title:
Noise and Correlations in a Spatial Population Model with Cyclic
  Competition

abstract:
  Noise and spatial degrees of freedom characterize most ecosystems. Some
aspects of their influence on the coevolution of populations with cyclic
interspecies competition have been demonstrated in recent experiments [e.g. B.
Kerr et al., Nature {\bf 418}, 171 (2002)]. To reach a better theoretical
understanding of these phenomena, we consider a paradigmatic spatial model
where three species exhibit cyclic dominance. Using an individual-based
description, as well as stochastic partial differential and deterministic
reaction-diffusion equations, we account for stochastic fluctuations and
spatial diffusion at different levels, and show how fascinating patterns of
entangled spirals emerge. We rationalize our analysis by computing the
spatio-temporal correlation functions and provide analytical expressions for
the front velocity and the wavelength of the propagating spiral waves.

categories: q-bio.PE cond-mat.stat-mech physics.bio-ph q-bio.QM


title: The Role of Galactic Winds on Molecular Gas Emission from Galaxy Mergers

abstract:
  We assess the impact of starburst and AGN feedback-driven winds on the CO
emission from galaxy mergers, and, in particular, search for signatures of
these winds in the simulated CO morphologies and emission line profiles. We do
so by combining a 3D non-LTE molecular line radiative transfer code with
smoothed particle hydrodynamics (SPH) simulations of galaxy mergers that
include prescriptions for star formation, black hole growth, a multiphase
interstellar medium (ISM), and the winds associated with star formation and
black hole growth. Our main results are: (1) Galactic winds can drive outflows
of masses ~10^8-10^9 Msun which may be imaged via CO emission line mapping. (2)
AGN feedback-driven winds are able to drive imageable CO outflows for longer
periods of time than starburst-driven winds owing to the greater amount of
energy imparted to the ISM by AGN feedback compared to star formation. (3)
Galactic winds can control the spatial extent of the CO emission in post-merger
galaxies, and may serve as a physical motivation for the sub-kiloparsec scale
CO emission radii observed in local advanced mergers. (4) Secondary emission
peaks at velocities greater than the circular velocity are seen in the CO
emission lines in all models. In models with winds, these high velocity peaks
are seen to preferentially correspond to outflowing gas entrained in winds,
which is not the case in the model without winds. The high velocity peaks seen
in models without winds are typically confined to velocity offsets (from the
systemic) < 1.7 times the circular velocity, whereas the models with AGN
feedback-driven winds can drive high velocity peaks to ~2.5 times the circular
velocity.


title: Signatures of LCDM substructure in tidal debris

abstract:
  In the past decade, surveys of the stellar component of the Galaxy have
revealed a number of streams from tidally disrupted dwarf galaxies and globular
clusters. Simulations of hierarchical structure formation in LCDM cosmologies
predict that the dark matter halo of a galaxy like the Milky Way contains
hundreds of subhalos with masses of ~10^8 solar masses and greater, and it has
been suggested that the existence of coherent tidal streams is incompatible
with the expected abundance of substructure. We investigate the effects of dark
matter substructure on tidal streams by simulating the disruption of a
self-gravitating satellite on a wide range of orbits in different host models
both with and without substructure. We find that the halo shape and the
specific orbital path more strongly determine the overall degree of disruption
of the satellite than does the presence or absence of substructure, i.e., the
changes in the large-scale properties of the tidal debris due to substructure
are small compared to variations in the debris from different orbits in a
smooth potential. Substructure typically leads to an increase in the degree of
clumpiness of the tidal debris in sky projection, and in some cases a more
compact distribution in line-of-sight velocity. Substructure also leads to
differences in the location of sections of debris compared to the results of
the smooth halo model, which may have important implications for the
interpretation of observed tidal streams. A unique signature of the presence of
substructure in the halo which may be detectable by upcoming surveys is
identified. We conclude, however, that predicted levels of substructure are
consistent with a detection of a coherent tidal stream from a dwarf galaxy.


title: Comparing Maintenance Strategies for Overlays

abstract:
  In this paper, we present an analytical tool for understanding the
performance of structured overlay networks under churn based on the
master-equation approach of physics. We motivate and derive an equation for the
average number of hops taken by lookups during churn, for the Chord network. We
analyse this equation in detail to understand the behaviour with and without
churn. We then use this understanding to predict how lookups will scale for
varying peer population as well as varying the sizes of the routing tables. We
then consider a change in the maintenance algorithm of the overlay, from
periodic stabilisation to a reactive one which corrects fingers only when a
change is detected. We generalise our earlier analysis to underdstand how the
reactive strategy compares with the periodic one.


title: Reduced zeta functions of Lie algebras

abstract:
  We define reduced zeta functions of Lie algebras, which can be derived from
motivic zeta functions using the Euler characteristic. We show that reduced
zeta functions of Lie algebras possessing a suitably well-behaved basis are
easy to analyse. We prove that reduced zeta functions are multiplicative under
certain conditions and investigate which reduced zeta functions have functional
equations.


title: Hawking radiation from extremal and non-extremal black holes

abstract:
  The relationship between Hawking radiation emitted by non extremal and
extremal Reissner Nordstrom black holes is critically analyzed. A careful study
of a series of regular collapsing geometries reveals that the stress energy
tensor stays regular in the extremal limit and is smoothly connected to that of
non extremal black holes. The unexpected feature is that the late time
transients which played little role in the non extremal case are necessary to
preserve the well defined character of the flux in the extremal case. The known
singular behavior of the static energy density of extremal black holes is
recovered from our series by neglecting these transients, when performing what
turns out to be an illegitimate late time limit. Although our results are
derived in two dimensional settings, we explain why they should also apply to
higher dimensional black holes.


title: Long wave expansions for water waves over random topography

abstract:
  In this paper, we study the motion of the free surface of a body of fluid
over a variable bottom, in a long wave asymptotic regime. We assume that the
bottom of the fluid region can be described by a stationary random process
$\beta(x, \omega)$ whose variations take place on short length scales and which
are decorrelated on the length scale of the long waves. This is a question of
homogenization theory in the scaling regime for the Boussinesq and KdV
equations. The analysis is performed from the point of view of perturbation
theory for Hamiltonian PDEs with a small parameter, in the context of which we
perform a careful analysis of the distributional convergence of stationary
mixing random processes. We show in particular that the problem does not fully
homogenize, and that the random effects are as important as dispersive and
nonlinear phenomena in the scaling regime that is studied. Our principal result
is the derivation of effective equations for surface water waves in the long
wave small amplitude regime, and a consistency analysis of these equations,
which are not necessarily Hamiltonian PDEs. In this analysis we compute the
effects of random modulation of solutions, and give an explicit expression for
the scattered component of the solution due to waves interacting with the
random bottom. We show that the resulting influence of the random topography is
expressed in terms of a canonical process, which is equivalent to a white noise
through Donsker's invariance principle, with one free parameter being the
variance of the random process $\beta$. This work is a reappraisal of the paper
by Rosales & Papanicolaou \cite{RP83} and its extension to general stationary
mixing processes.


title: Moving and ample cones of holomorphic symplectic fourfolds

abstract:
  We analyze the ample and moving cones of holomorphic symplectic manifolds, in
light of recent advances in the minimal model program. As an application, we
establish a numerical criterion for ampleness of divisors on fourfolds
deformation-equivalent to punctual Hilbert schemes of K3 surfaces.


title: Dynamical Phase Transitions In Driven Integrate-And-Fire Neurons

abstract:
  We explore the dynamics of an integrate-and-fire neuron with an oscillatory
stimulus. The frustration due to the competition between the neuron's natural
firing period and that of the oscillatory rhythm, leads to a rich structure of
asymptotic phase locking patterns and ordering dynamics. The phase transitions
between these states can be classified as either tangent or discontinuous
bifurcations, each with its own characteristic scaling laws. The discontinuous
bifurcations exhibit a new kind of phase transition that may be viewed as
intermediate between continuous and first order, while tangent bifurcations
behave like continuous transitions with a diverging coherence scale.


title:
Line Broadening in Field Metal-poor Red Giant and Red Horizontal Branch
  Stars

abstract:
  We report 349 radial velocities for 45 metal-poor field red giant and red
horizontal branch stars. We have have identified one new spectroscopic binary,
HD 4306, and one possible such system, HD 184711. We also report 57 radial
velocities for 11 of the 91 stars reported on previously by Carney et al.
(2003). As was found in the previous study, radial velocity "jitter" is present
in many of the most luminous stars. Excluding stars showing spectroscopic
binary orbital motion, all 7 of the red giants with M(V) <= -2.0 display
jitter, as well as 3 of the 14 stars with -2.0 <= M(V) <= -1.4. We have also
measured line broadening in all of the new spectra, using synthetic spectra as
templates. The most luminous red giants show significant line broadening, as do
many of the red horizontal branch stars, and we discuss briefly possible
causes.


title: Quark scattering amplitudes at strong coupling

abstract:
  Following Alday and Maldacena, we describe a string theory method to compute
the strong coupling behavior of the scattering amplitudes of quarks and gluons
in planar N=2 super Yang-Mills theory in the probe approximation. Explicit
predictions for these quantities can be constructed using the all-orders planar
gluon scattering amplitudes of N=4 super Yang-Mills due to Bern, Dixon and
Smirnov.


title: Higman's PORC conjecture for a family of groups

abstract:
  We prove that the number of groups of order $p^n$ whose Frattini subgroup is
central is for fixed $n$ a PORC (`polynomial on residue classes') function of
$p$. This extends a result of G. Higman.


title: Bootes II: Not a Dwarf Galaxy but Possibly Shed by One

abstract: This paper has been withdrawn due to a photometric calibration error.


title:
Higher-order splitting algorithms for solving the nonlinear
  Schr\"odinger equation and their instabilities

abstract:
  Since the kinetic and the potential energy term of the real time nonlinear
Schr\"odinger equation can each be solved exactly, the entire equation can be
solved to any order via splitting algorithms. We verified the fourth-order
convergence of some well known algorithms by solving the Gross-Pitaevskii
equation numerically. All such splitting algorithms suffer from a latent
numerical instability even when the total energy is very well conserved. A
detail error analysis reveals that the noise, or elementary excitations of the
nonlinear Schr\"odinger, obeys the Bogoliubov spectrum and the instability is
due to the exponential growth of high wave number noises caused by the
splitting process. For a continuum wave function, this instability is
unavoidable no matter how small the time step. For a discrete wave function,
the instability can be avoided only for $\dt k_{max}^2{<\atop\sim}2 \pi$, where
$k_{max}=\pi/\Delta x$.


title: Theory of Pulsar Wind Nebulae

abstract:
  Our understanding of Pulsar Wind Nebulae (PWNe), has greatly improved in the
last years thanks to unprecedented high resolution images taken from the
HUBBLE, CHANDRA and XMM satellites. The discovery of complex but similar inner
features, with the presence of unexpected axisymmetric rings and jets, has
prompted a new investigation into the dynamics of the interaction of the pulsar
winds with the surrounding SNR, which, thanks to the improvement in the
computational resources, has let to a better understanding of the properties of
these objects. On the other hand the discovery of non-thermal emission from bow
shock PWNe, and of systems with a complex interaction between pulsar and SNR,
has led to the development of more reliable evolutionary models. I will review
the standard theory of PWNe, their evolution, and the current status in the
modeling of their emission properties, in particular I will show that our
evolutionary models are able to describe the observations, and that the X-ray
emission can now be reproduced with sufficient accuracy, to the point that we
can use these nebulae to investigate fundamental issues as the properties of
relativistic outflows and particle acceleration.


title: Spin Supersolid in Anisotropic Spin-One Heisenberg Chain

abstract:
  We consider an S=1 Heisenberg chain with strong exchange (Delta) and
single--ion uniaxial anisotropy (D) in a magnetic field (B) along the symmetry
axis. The low energy spectrum is described by an effective S=1/2 XXZ model that
acts on two different low energy sectors for a given window of fields. The
vacuum of each sector exhibits Ising-like antiferromagnetic ordering that
coexists with the finite spin stiffness obtained from the exact solution of the
effective XXZ model. In this way, we demonstrate the existence of a spin
supersolid phase. We also compute the full Delta-B quantum phase diagram by
means of a quantum Monte Carlo simulation.


title: Inhomogeneous Diophantine approximation of some Hurwitzian numbers

abstract:
  We continue the work of Takao Komatsu by considering the inhomogeneous
approximation constant L(\theta,\phi) for Hurwitzian numbers \theta, and
rationally related \phi(r \theta +m)/n in Q(\theta) +Q. The current work uses a
compactness theorem to relate such inhomogeneous constants to the homogeneous
approximation constants. Among the new results are: a characterization of such
pairs \theta,\phi for which L(\theta,\phi) is zero; consideration of small
values of n^2 L(e^{2/s},\phi); and the proof of a conjecture of Komatsu.


title:
Metal-insulator transition from combined disorder and interaction
  effects in Hubbard-like electronic lattice models with random hopping

abstract:
  We uncover a disorder-driven instability in the diffusive Fermi liquid phase
of a class of many-fermion systems, indicative of a metal-insulator transition
of first order type, which arises solely from the competition between quenched
disorder and interparticle interactions. Our result is expected to be relevant
for sufficiently strong disorder in d = 3 spatial dimensions. Specifically, we
study a class of half-filled, Hubbard-like models for spinless fermions with
(complex) random hopping and short-ranged interactions on bipartite lattices,
in d > 1. In a given realization, the hopping disorder breaks time reversal
invariance, but preserves the special ``nesting'' symmetry responsible for the
charge density wave instability of the ballistic Fermi liquid. This disorder
may arise, e.g., from the application of a random magnetic field to the
otherwise clean model. We derive a low energy effective field theory
description for this class of disordered, interacting fermion systems, which
takes the form of a Finkel'stein non-linear sigma model [A. M. Finkel'stein,
Zh. Eksp. Teor. Fiz. 84, 168 (1983), Sov. Phys. JETP 57, 97 (1983)]. We analyze
the Finkel'stein sigma model using a perturbative, one-loop renormalization
group analysis controlled via an epsilon-expansion in d = 2 + epsilon
dimensions. We find that, in d = 2 dimensions, the interactions destabilize the
conducting phase known to exist in the disordered, non-interacting system. The
metal-insulator transition that we identify in d > 2 dimensions occurs for
disorder strengths of order epsilon, and is therefore perturbatively accessible
for epsilon << 1. We emphasize that the disordered system has no localized
phase in the absence of interactions, so that a localized phase, and the
transition into it, can only appear due to the presence of the interactions.


title:
The impact of localized overlap eigenmodes on RMT measurements and
  topology

abstract:
  The low energy eigenmodes of the continuum QCD Dirac operator are extended,
but on the lattice, due to discretization effects, the Dirac operator can have
localized eigenmodes. These non-physical modes can introduce strong lattice
artifacts for observables that are sensitive to chiral symmetry, especially in
mixed action simulations. We study how these lattice artifacts depend on the
parameters of the overlap operator and their affect on the distribution on the
Dirac eigenmodes and the topological susceptibility.


title:
The XMM-Newton Serendipitous Survey V. Optical identification of the
  XMM-Newton Medium sensitivity Survey (XMS)

abstract:
  We present the XMM-Newton Medium sensitivity Survey (XMS), including a total
of 318 X-ray sources found among the serendipitous content of 25 XMM-Newton
target fields. The XMS comprises four largely overlapping source samples
selected at soft (0.5-2 keV), intermediate (0.5-4.5 keV), hard (2-10 keV) and
ultra-hard (4.5-7.5 keV) bands, the first three of them being flux-limited. We
report on the optical identification of the XMS samples, complete to 85-95%. At
the intermediate flux levels sampled by the XMS we find that the X-ray sky is
largely dominated by Active Galactic Nuclei. The fraction of stars in soft
X-ray selected samples is below 10%, and only a few per cent for hard selected
samples. We find that the fraction of optically obscured objects in the AGN
population stays constant at around 15-20% for soft and intermediate band
selected X-ray sources, over 2 decades of flux. The fraction of obscured
objects amongst the AGN population is larger (~35-45%) in the hard or
ultra-hard selected samples, and constant across a similarly wide flux range.
The distribution in X-ray-to-optical flux ratio is a strong function of the
selection band, with a larger fraction of sources with high values in hard
selected samples. Sources with X-ray-to-optical flux ratios in excess of 10 are
dominated by obscured AGN, but with a significant contribution from unobscured
AGN.


title: Area-expanding embeddings of rectangles

abstract:
  We estimate whether there is an embedding from one n-dimensional rectangle
into another which expands every k-dimensional area. Our estimate is sharp up
to a constant factor in each dimension.


title: Rolling Tachyon in Nonlocal Cosmology

abstract:
  Nonlocal cosmological models derived from String Field Theory are considered.
A new method for constructing rolling tachyon solutions in the FRW metric in
two field configuration is proposed and solutions of the Friedman equations
with nonlocal operator are presented. The cosmological properties of these
solutions are discussed.


title:
Open-Loop Woofer-Tweeter Control on the LAO Multi-Conjugate Adaptive
  Optics Testbed

abstract:
  Advances in micro deformable mirror (DM) technologies such as MEMs, have
stimulated interest in the characteristics of systems that include a high
stroke mirror in series with a high actuator count mirror. This arrangement is
referred to as a woofer-tweeter system. In certain situations it may be
desirable or necessary to operate the woofer DM in open-loop. We present a
simple method for controlling a woofer DM in open loop provided the device
behaves in an approximately linear fashion. We have tested a mirror that we
believe meets our criterion, the ALPAO DM52 mirror. Using our open-loop method
we fit several test Kolmogorov wavefronts with the mirror and have achieved an
accuracy of approximately 25 nm rms surface deviation over the whole clear
aperture, and 20 nm rms over 90% of the aperture. We have also flattened the
mirror in open loop to approximately 11 nm rms residual.


title: A Population of Massive and Evolved Galaxies at z$\ga$5

abstract:
  We report results from a search for massive and evolved galaxies at z>5 in
the GOODS southern field. Combining HST ACS, VLT ISAAC and Spitzer IRAC
photometric data, we develop a color selection technique to identify candidates
for being evolved galaxies at high redshifts. The color selection is primarily
based on locating the Balmer-break using the K- and 3.6micron bands. Stellar
population synthesis models are fitted to the SEDs of these galaxies to
identify the final sample. We find 11 candidates with photometric redshifts in
the range 4.9 < z < 6.5, dominated by an old stellar population, with ages
0.2-1.0 Gyr, and stellar masses in the range (0.5 - 5) 10^{11} Msun. The
majority of the stars in these galaxies were formed at z > 9. One candidate has
a spectroscopically confirmed redshift, in good agreement with our photometric
redshift. The galaxies are very compact, with half-light radii in the observed
K-band smaller than ~2 kpc. Seven of the 11 candidates are also detected at
24micron with the MIPS instrument on Spitzer. The 24micron emission could be
interpreted as PAH emission from a dusty starburst at z~2-3, however, it is
also consistent with the presence of an obscured AGN at z>5. We estimate the
completeness of the Balmer break galaxy sample to be ~40%. The comoving number
density of galaxies with a stellar mass >10^{11} Msun, at an average redshift
z=5.2, is 3.9 10^{-5} Mpc^{-3} (no-MIPS sample: 1.4 10^{-5} Mpc^{-3}). The
corresponding stellar mass density is 8 10^{6} Msun/Mpc^3 (no-MIPS sample: 6.2
10^6 Msun/Mpc^3).


title:
Instabilities of Spiral Shocks -- II. A quasi-steady State in the
  multi-phase inhomogeneous ISM

abstract:
  The ``galactic shocks'' \citep{fujimoto68,roberts69} is investigated using a
full three-dimensional hydrodynamic simulations, taking into account
self-gravity of the ISM, radiative cooling, and star formation followed by
energy feedback from supernovae. This is an essential progress from the
previous numerical models, in which 2-D isothermal, non-self-gravitating gas is
assumed. We find that the classic galactic shocks appears is unstable and
transient, and it shifts to a globally quasi-steady, inhomogeneous pattern due
to non-linear development of instabilities in the disk. The spiral patterns
consists of many GMC-like dense condensations, but those local structures are
not steady, and they evolves into irregular spurs in the inter-arm regions.
Energy feedback from supernovae do not destroy the quasi-steady spiral arms,
but it mainly contributes to vertical motion and structures of the ISM.


title: Optimal Transportation under Nonholonomic Constraints

abstract:
  We study Monge's optimal transportation problem, where the cost is given by
optimal control cost. We prove the existence and uniqueness of an optimal map
under certain regularity conditions on the Lagrangian, absolute continuity of
the measures with respect to Lebesgue, and most importantly the absence of
sharp abnormal minimizers. In particular, this result is applicable in the case
of subriemannian manifolds with a 2-generating distribution and cost given by
$d^2$, where $d$ is the subriemannian distance. Also, we discuss some
properties of the optimal plan when abnormal minimizers are present. Finally,
we consider some examples of displacement interpolation in the case of Grushin
plane.


title: On potentially $K_{r+1}-U$-graphical Sequences

abstract:
  Let $K_{m}-H$ be the graph obtained from $K_{m}$ by removing the edges set
$E(H)$ of the graph $H$ ($H$ is a subgraph of $K_{m}$). We use the symbol $Z_4$
to denote $K_4-P_2.$ A sequence $S$ is potentially $K_{m}-H$-graphical if it
has a realization containing a $K_{m}-H$ as a subgraph. Let $\sigma(K_{m}-H,
n)$ denote the smallest degree sum such that every $n$-term graphical sequence
$S$ with $\sigma(S)\geq \sigma(K_{m}-H, n)$ is potentially $K_{m}-H$-graphical.
In this paper, we determine the values of $\sigma (K_{r+1}-U, n)$ for
  $n\geq 5r+18, r+1 \geq k \geq 7,$ $j \geq 6$ where $U$ is a graph on $k$
vertices and $j$ edges which contains a graph $K_3 \bigcup P_3$ but not
contains a cycle on 4 vertices and not contains $Z_4$. There are a number of
graphs on $k$ vertices and $j$ edges which contains a graph $(K_{3} \bigcup
P_{3})$ but not contains a cycle on 4 vertices and not contains $Z_4$. (for
example, $C_3\bigcup C_{i_1} \bigcup C_{i_2} \bigcup >... \bigcup C_{i_p}$
$(i_j\neq 4, j=2,3,..., p, i_1 \geq 5)$, $C_3\bigcup P_{i_1} \bigcup P_{i_2}
\bigcup ... \bigcup P_{i_p}$ $(i_1 \geq 3)$, $C_3\bigcup P_{i_1} \bigcup
C_{i_2} \bigcup >... \bigcup C_{i_p}$ $(i_j\neq 4, j=2,3,..., p, i_1 \geq 3)$,
etc)


title:
The Theory of Unified Relativity for a Biovielectroluminescence
  Phenomenon via Fly's Visual and Imaging System

abstract:
  The elucidation upon fly's neuronal patterns as a link to computer graphics
and memory cards I/O's, is investigated for the phenomenon by propounding a
unified theory of Einstein's two known relativities. It is conclusive that
flies could contribute a certain amount of neuromatrices indicating an imagery
function of a visual-computational system into computer graphics and storage
systems. The visual system involves the time aspect, whereas flies possess
faster pulses compared to humans' visual ability due to the E-field state on an
active fly's eye surface. This behaviour can be tested on a dissected fly
specimen at its ommatidia. Electro-optical contacts and electrodes are wired
through the flesh forming organic emitter layer to stimulate light emission,
thereby to a computer circuit. The next step is applying a threshold voltage
with secondary voltages to the circuit denoting an array of essential
electrodes for bit switch. As a result, circuit's dormant pulses versus active
pulses at the specimen's area are recorded. The outcome matrix possesses a
construction of RGB and time radicals expressing the time problem in
consumption, allocating time into computational algorithms, enhancing the
technology far beyond. The obtained formulation generates consumed distance
cons(x), denoting circuital travel between data source/sink for pixel data and
bendable wavelengths. Once 'image logic' is in place, incorporating this point
of graphical acceleration permits one to enhance graphics and optimize
immensely central processing, data transmissions between memory and computer
visual system. The phenomenon can be mainly used in 360-deg. display/viewing,
3D scanning techniques, military and medicine, a robust and cheap substitution
for e.g. pre-motion pattern analysis, real-time rendering and LCDs.


title: Theoretical topics in spacetime-symmetry violations

abstract:
  The Lorentz- and CPT-violating Chern-Simons extension of electrodynamics is
considered. In the context of N=4 supergravity in four spacetime dimensions, it
is argued that cosmological solutions can generate this extension. Within
Chern-Simons electrodynamics, theoretical and phenomenological topics are
reviewed that concern the number of the remaining spacetime symmetries and the
vacuum Cherenkov effect, respectively.


title:
What's up with IR gluon and ghost propagators in Landau gauge? A
  puzzling answer from huge lattices

abstract:
  Several analytic approaches predict for SU(N_c) Yang-Mills theories in Landau
gauge an enhanced ghost propagator G(p^2) and a suppressed gluon propagator
D(p^2) at small momenta. This prediction applies to two, three and four
space-time dimensions. Moreover, the gluon propagator is predicted to be null
at p = 0. Numerical studies by several groups indeed support an enhanced ghost
propagator when compared to the tree-level behavior $1/p^2$ and a finite
infrared gluon propagator. However, the agreement between analytic and
numerical studies is only at the qualitative level in three and in four
dimensions. In particular, the infrared exponent of the ghost propagator seems
to be smaller than the one predicted analytically and the gluon propagator
seems to display a (finite) nonzero value at zero momentum. It has been argued
that this discrepancy might go away once simulations are done on much larger
lattice sizes than the ones used up to now. Here we present data in three and
four space-time dimensions using huge lattices in the scaling region, i.e. up
to 320^3 at beta = 3.0 and up to 128^4 at beta = 2.2, corresponding to V
\approx (85 fm)^3 and V \approx (27 fm)^4. Simulations have been done on the
IBM supercomputer at the University of Sao Paulo


title: Chiral behaviour of Delta B = 2 and Delta C =2 matrix elements

abstract:
  We investigate the light-quark mass and spatial volume dependence of matrix
elements of Delta B = 2 and Delta C = 2 four-fermion operators. These operators
are relevant for Neutral B(s) and D mixing in and beyond the Standard Model. An
important conclusion of this work is that the chiral extrapolations for matrix
elements of heavy-light meson mixing beyond the Standard Model are more
complicated than that for the Standard Model mixing matrix elements.


title: Electron as soliton: Nonlinear theory of dielectric polarization

abstract:
  We describe a class of theories of dielectric polarization and a species of
solitons in these theories. The solitons, made entirely out of the polarization
field, have quantized values of the electric charge and can be interpreted as
electrons and holes. A soliton-antisoliton pair is an exciton. We present
numerical evidence that the elementary soliton is stable.


title: Measurement of triple differential photon plus jet cross section by D0

abstract:
  We report on a new measurement of triple differential cross section for the
process ppbar -> photon + jet + X in ppbar collisions at sqrt(s)=1.96 TeV by
the D0 Collaboration at Fermilab based on a dataset corresponding to an
integrated luminosity of 1.1 fb-1.


title:
Effective Dynamics, Big Bounces and Scaling Symmetry in Bianchi Type I
  Loop Quantum Cosmology

abstract:
  The detailed formulation for loop quantum cosmology (LQC) in the Bianchi I
model with a scalar massless field has been constructed. In this paper, its
effective dynamics is studied in two improved strategies for implementing the
LQC discreteness corrections. Both schemes show that the big bang is replaced
by the big bounces, which take place up to three times, once in each diagonal
direction, when the area or volume scale factor approaches the critical values
in the Planck regime measured by the reference of the scalar field momentum.
These two strategies give different evolutions: In one scheme, the effective
dynamics is independent of the choice of the finite sized cell prescribed to
make Hamiltonian finite; in the other, the effective dynamics reacts to the
macroscopic scales introduced by the boundary conditions. Both schemes reveal
interesting symmetries of scaling, which are reminiscent of the relational
interpretation of quantum mechanics and also suggest that the fundamental
spatial scale (area gap) may give rise to a temporal scale.


title:
Quantum capacity of lossy channel with additive classical Gaussian noise
  : a perturbation approach

abstract:
  For a quantum channel of additive Gaussian noise with loss, in the general
case of $n$ copies input, we show that up to first order perturbation, any
non-Gaussian perturbation to the product thermal state input has a less quantum
information transmission rate when the input energy tend to infinitive.


title: Neutron Star Crustal Mass Fractions

abstract:
  We are investigating mass fractions on the crust of a neutron star which
would remain after one year of cooling. We use cooling curves corresponding
with various densities, or depths, of the neutron star just after its
formation. We assume the modified Urca process dominates the energy budget of
the outer layers of the star in order to calculate the temperature of the
neutron star as a function of time. Using a nuclear reaction network up to
technetium, we calculate how the distribution of nuclei quenches at various
depths of the neutron star crust. The initial results indicate that $^{28}$Si
is the lightest isotope to be optically thick on the surface after one year of
cooling.


title: Gravitational Collapse and Radiation of Grand Unified Theory

abstract:
  The infinite gravitational collapse of any supermassive stars should pass
through an energy scale of the grand unified theory (GUT). After
nucleon-decays, the supermassive star will convert nearly all its mass into
energy, and produce the radiation of GUT. It may probably explain some
ultrahigh energy puzzles in astrophysics, for example, quasars and gamma-ray
bursts (GRB), etc. This is similar with a process of the Big Bang Universe with
a time-reversal evolution in much smaller space scale and mass scale. In this
process the star seems be a true white hole.


title: Leptonic and semileptonic D and D_s decays at B-factories

abstract:
  Recent measurements of branching fractions, form factors and decay constants
of leptonic and semileptonic decays of D_(s)-mesons acquired at experiments
running at the Upsilon(4S) resonance energy are reviewed.


title: DBI Global Strings

abstract:
  In this note we present global string solutions which are a generalization of
the usual field theory global vortices when the kinetic term is DBI. Such
vortices can result from the spontaneous symmetry breaking in the potential
felt by a D3-brane. In a previous paper (0706.0485), the DBI instanton solution
was constructed which develops a "wrinkle" for stringy heights of the
potential. A similar effect is also seen for the DBI vortex solution. The
wrinkle develops for stringy heights of the potential. One recovers the usual
field theory global string for substringy potentials. As an example of the
symmetry breaking, we consider a mobile D3-brane on the warped deformed
conifold. Symmetry breaking can occur if the structure of the vacuum manifold
of the potential for the D3-brane changes as it moves through the throat
region.


title:
Nucleon form factors and structure functions with N_f=2+1 dynamical
  domain wall fermions

abstract:
  We report isovector form factors and low moments of structure functions of
nucleon in numerical lattice quantum chromodynamics (QCD) from the on-going
calculations by the RIKEN-BNL-Columbia (RBC) and UKQCD Collaborations with
(2+1) dynamical flavors of domain-wall fermion (DWF) quarks. We calculate the
matrix elements with four light quark masses, corresponding to pion mass values
of m_\pi = 330-670 MeV, while the dynamical strange mass is fixed at a value
close to physical, on (2.7 fm)^3 spatial volume. We found that our axial
charge, g_A, at the lightest mass exhibits a large deviation from the heavier
mass results. This deviation seems to be a finite-size effect as the g_A value
scales with a single parameter, m_\pi L, the product of pion mass and linear
spatial lattice size. The scaling is also seen in earlier 2-flavor dynamical
DWF and Wilson quark calculations. Without this lightest point, the three
heavier mass results show only very mild mass dependence and linearly
extrapolate to g_A=1.16(6). We determined the four form factors, the vector
(Dirac), induced tensor (Pauli), axial vector and induced pseudoscalar, at a
few finite momentum transfer values as well. At the physical pion mass the
form-factors root mean square radii determined from the momentum-transfer
dependence %of the form factors are 20-30% smaller than the corresonding
experiments. The ratio of the isovector quark momentum to helicity fractions, <
x>_{u-d}/< x>_{\Delta u - \Delta d} is in agreement with experiment without
much mass dependence including the lightest point. We obtain an estimate,
0.81(2), by a constant fit. Although the individual momentum and helicity
fractions are yet to be renormalized, they show encouraging trend toward
experiment.


title: Effective Lagrangian of Domain Wall Networks

abstract:
  Domain wall networks are studied in N=2 supersymmetric U(N_C) gauge theory
with N_F (>N_C) flavors. We find a systematic method to construct domain wall
networks in terms of moduli matrices. Normalizable moduli parameters of the
network are found to be sizes and phases of the loop. We obtain moduli space
metric which specifies the effective Lagrangian on the domain wall networks. It
is used to study dynamics of domain wall networks with the moduli
approximation.


title:
Simulating Magnetohydrodynamical Flow with Constrained Transport and
  Adaptive Mesh Refinement; Algorithms & Tests of the AstroBEAR Code

abstract:
  A description is given of the algorithms implemented in the AstroBEAR
adaptive mesh refinement code for ideal magnetohydrodynamics. The code provides
several high resolution, shock capturing schemes which are constructed to
maintain conserved quantities of the flow in a finite volume sense. Divergence
free magnetic field topologies are maintained to machine precision by collating
the components of the magnetic field on a cell-interface staggered grid and
utilizing the constrained transport approach for integrating the induction
equations. The maintenance of magnetic field topologies on adaptive grids is
achieved using prolongation and restriction operators which preserve the
divergence and curl of the magnetic field across co-located grids of different
resolution. The robustness and correctness of the code is demonstrated by
comparing the numerical solution of various tests with analytical solutions or
previously published numerical solutions obtained by other codes.


title: Oscillatory terms in the domain wall transfer matrix

abstract:
  We study the transfer matrix for domain wall fermions to understand the
origin and significance of oscillatory contributions to hadron correlation
functions that arise for M >1. For a free particle in one space, one time, and
one flavor dimension, the eigenmodes of the one-body operator appearing in the
transfer matrix are calculated, and the role of the negative eigenmodes arising
when M > 1 is studied. In the case of three space dimensions, oscillatory
behavior for hadron correlation functions in QCD is shown to emerge for free
fermions when M exceeds 1, and to increase with increasing M. Analogous
behavior is observed for domain wall fermions on HYP smeared MILC lattices, and
a procedure is demonstrated for subtracting oscillating terms from physical
observables.


title: Morphologies of Two Massive Old Galaxies at z ~ 2.5

abstract:
  We present the results of NICMOS imaging of two massive galaxies
photometrically selected to have old stellar populations at z ~ 2.5. Both
galaxies are dominated by apparent disks of old stars, although one of them
also has a small bulge comprising about 1/3 of the light at rest-frame 4800 A.
The presence of massive disks of old stars at high redshift means that at least
some massive galaxies in the early universe have formed directly from the
dissipative collapse of a large mass of gas. The stars formed in disks like
these may have made significant contributions to the stellar populations of
massive spheroids at the present epoch.


title: Effective Interactions In Neutron-Rich Matter

abstract:
  Properties of effective interactions in neutron-rich matter are reflected in
the medium's equation of state (EOS), which is a relationship among several
state variables. Spin and isospin asymmetries play an important role in the
energy balance and could alter the stability conditions of the nuclear EOS. The
EOS has far-reaching consequences for numerous nuclear processes in both the
terrestrial laboratories and the cosmos. Presently the EOS, especially for
neutron-rich matter, is still very uncertain. Heavy-ion reactions provide a
unique means to constrain the EOS, particularly the density dependence of the
nuclear symmetry energy. On the other hand, microscopic, self-consistent, and
parameter-free approaches are ultimately needed for understanding nuclear
properties in terms of the fundamental interactions among the basic
constituents of nuclear systems. In this talk, after a brief review of our
recent studies on spin-polarized neutron matter, we discuss constraining the
changing rate of the gravitational constant $G$ and properties of (rapidly)
rotating neutron stars by using a nuclear EOS partially constrained by the
latest terrestrial nuclear laboratory data.


title: Nature of time and causality in Physics

abstract:
  The conceptual definition and understanding of the nature of time, both
qualitatively and quantitatively is of the utmost difficulty and importance,
and plays a fundamental role in physics. Physical systems seem to evolve in
paths of increasing entropy and of complexity, and thus, the arrow of time
shall be explored in the context of thermodynamic irreversibility and quantum
physics. In Newtonian physics, time flows at a constant rate, the same for all
observers; however, it necessarily flows at different rates for different
observers in special and general relativity. Special relativity provides
important quantitative elucidations of the fundamental processes related to
time dilation effects, and general relativity provides a deep analysis to
effects of time flow, such as in the presence of gravitational fields. Through
the special theory of relativity, time became intimately related with space,
giving rise to the notion of spacetime, in which both parameters cannot be
considered as separate entities. As time is incorporated into the proper
structure of the fabric of spacetime, it is interesting to note that general
relativity is contaminated with non-trivial geometries that generate closed
timelike curves, and thus apparently violates causality. The notion of
causality is fundamental in the construction of physical theories; therefore
time travel and its associated paradoxes have to be treated with great caution.
These issues are briefly analyzed in this review paper.


title: Operated semigroups, Motzkin paths and rooted trees

abstract:
  Combinatorial objects such as rooted trees that carry a recursive structure
have found important applications recently in both mathematics and physics. We
put such structures in an algebraic framework of operated semigroups. This
framework provides the concept of operated semigroups with intuitive and
convenient combinatorial descriptions, and at the same time endows the familiar
combinatorial objects with a precise algebraic interpretation. As an
application, we obtain constructions of free Rota-Baxter algebras in terms of
Motzkin paths and rooted trees.


title:
Darboux Transformation for the Non-isospectral AKNS Hierarchy and Its
  Asymptotic Property

abstract:
  In this article, the Darboux transformation for the non-isospectral AKNS
hierarchy is constructed. We show that the Darboux transformation for the
non-isospectral AKNS hierarchy is not an auto-B\"acklund transformation,
because the integral constants of the hierarchy will be changed after the
transformation. The transform rule of the integral constants will be also
derived. By this means, the soliton solutions of the nonlinear equations
derived by the non-isospectral AKNS hierarchy can be found.


title: New Counting Codes for Distributed Video Coding

abstract:
  This paper introduces a new counting code. Its design was motivated by
distributed video coding where, for decoding, error correction methods are
applied to improve predictions. Those error corrections sometimes fail which
results in decoded values worse than the initial prediction. Our code exploits
the fact that bit errors are relatively unlikely events: more than a few bit
errors in a decoded pixel value are rare. With a carefully designed counting
code combined with a prediction those bit errors can be corrected and sometimes
the original pixel value recovered. The error correction improves
significantly. Our new code not only maximizes the Hamming distance between
adjacent (or "near 1") codewords but also between nearby (for example "near 2")
codewords. This is why our code is significantly different from the well-known
maximal counting sequences which have maximal average Hamming distance.
Fortunately, the new counting code can be derived from Gray Codes for every
code word length (i.e. bit depth).


title:
Differential Birkhoff decomposition and the renormalization of multiple
  zeta values

abstract:
  In the Hopf algebra approach of Connes and Kreimer on renormalization of
quantum field theory, the renormalization process is views as a special case of
the Algebraic Birkhoff Decomposition. We give a differential algebra variation
of this decomposition and apply this to the study of multiple zeta values.


title: Rota-Baxter operators on generalized power series rings

abstract:
  An important instance of Rota-Baxter algebras from their quantum field theory
application is the ring of Laurent series with a suitable projection. We view
the ring of Laurent series as a special case of generalized power series rings
with exponents in an ordered monoid. We study when a generalized power series
ring has a Rota-Baxter operator and how this is related to the ordered monoid.


title: I=2 Two-Pion Wave Functions with Non-zero Total Momentum

abstract:
  We calculate the two-pion wave function for the I=2 $S$-wave two-pion system
with a finite scattering momentum and estimate the interaction range between
two pions. It allows us to examine the validity of the necessary condition for
the finite-volume method for the scattering phase shift. A calculation is
carried out with a plaquette gauge action for gluons and a clover-improved
Wilson action for quarks at $1/a=1.63 {\rm GeV}$ on $32^3\times 120$ lattice in
the quenched approximation. We conclude that the necessary condition is
satisfied within statistical errors for the lattice size $L\ge 32$, when the
quark mass is in the range $m_\pi^2=0.176 - 0.345 {\rm GeV}^2$ and the
scattering momentum in $k^2 < 0.026 {\rm GeV}^2$. We also find that the energy
dependence of the interaction range is small and it takes $1.2-1.7 {\rm fm}$
for our simulation parameters. We obtain the phase shift from the two-pion wave
function with a smaller statistical error than that from the conventional
analysis with the two-pion time correlator.


title:
Entanglement, recoherence and information flow in an accelerated
  detector - quantum field system: Implications for black hole information
  issue

abstract:
  We study an exactly solvable model where an uniformly accelerated detector is
linearly coupled to a massless scalar field initially in the Minkowski vacuum.
Using the exact correlation functions we show that as soon as the coupling is
switched on one can see information flowing from the detector to the field and
propagating with the radiation into null infinity. By expressing the reduced
density matrix of the detector in terms of the two-point functions, we
calculate the purity function in the detector and study the evolution of
quantum entanglement between the detector and the field. Only in the ultraweak
coupling regime could some degree of recoherence in the detector appear at late
times, but never in full restoration. We explicitly show that under the most
general conditions the detector never recovers its quantum coherence and the
entanglement between the detector and the field remains large at late times. To
the extent this model can be used as an analog to the system of a black hole
interacting with a quantum field, our result seems to suggest in the prevalent
non-Markovian regime, assuming unitarity for the combined system, that black
hole information is not lost but transferred to the quantum field degrees of
freedom. Our combined system will evolve into a highly entangled state between
a remnant of large area (in Bekenstein's black hole atom analog) without any
information of its initial state, and the quantum field, now imbued with
complex information content not-so-easily retrievable by a local observer.


title: Application of Quantum Theory to Super-parametric Density Estimation

abstract:
  In this paper, we will discuss how to generalize nonparametric density
estimators to MLE parametric estimators. Basing on the Parzen window theory and
using the advantages of probability amplitude of quantum theory, we model a
nonlinear optimization problem and it is very difficult, if not impossible, to
solve the problem. A constructive procedure for solving the nonlinear
programming problem is studied. Though it seems to be very complicated, the
approach of this paper is simple and comprehensive. More precisely, the lemmas,
the theorems and their proofs serve the purpose for mathematical rigor and
practical computation. Instead of using techniques and terminologies of
advanced mathematics, we use the popular techniques and terminologies of
elementary calculus. From the numerical results of the paper by Y. --S. Tsai et
al. [7], it shows that a new approach of density estimation, super-parametric
density estimation, is established completely. Strictly speaking, the work of
the paper is not confined in the category of statistics. It could be classified
into nonlinear analysis such as optimization on linear space, or manifold, and
the algorithm of computer science.


title:
Connectivity of the Product Replacement Graph of Simple Groups of
  Bounded Lie Rank

abstract:
  The Product Replacement Algorithm is a practical algorithm for generating
random elements of a finite group. The algorithm can be described as a random
walk on a graph whose vertices are the generating k-tuples of the group (for a
fixed integer k).
  We show that there is a function c(r) such that for any finite simple group
of Lie type, with Lie rank r, the product replacement graph of the generating
k-tuples is connected for any k > c(r).
  The proof uses results of Larsen and Pink and does not rely on the
classification of finite simple groups.


title: A Lattice Formulation of Two Dimensional Topological Field Theory

abstract:
  We propose a non-perturbative criterion to investigate whether supersymmetric
lattice gauge theories preserving partial SUSY can have the desired continuum
limit or not. Since the target continuum theories of the lattice models are
extended supersymmetric gauge theories including the topological field theory
(TFT) as a special subsector, the continuum limits of them should reproduce the
properties of the TFT. Therefore, whether the property of the TFT can be
recovered at the continuum limit becomes a non-perturbative criterion. Then we
accept it as a criterion. In this paper, among the topological properties, we
investigate the BRST cohomology on the two dimensional ${\mathcal N}=(4,4)$
CKKU lattice model without moduli fixing mass term. We show that the BRST
cohomology in the target continuum theory cannot be realized from the BRST
cohomology on the lattice. From this result, we obtain the possible implication
that the ${\mathcal N} = (4,4)$ CKKU model cannot recover the target continuum
theory if the non-perturbative effects are taken into account.


title:
Superconducting properties of Pr-based Filled skutterudite
  PrRu$_4$As$_{12}$

abstract:
  We report on systematic study of superconducting characteristics and Pr
crystalline-electric-field (CEF) levels of filled-skutterudite \pra ($T_{\rm
c}$ = 2.33 K). The temperature dependences of the upper critical field $H_{\rm
c2}$ and the Ginzburg-Landau (Maki) parameter $\kappa_2$ suggest an s-wave
clean-limit superconductivity. The electronic specific heat coefficient $\gamma
\sim 95$ mJ/K$^2$mol, being $\sim 1.5$ times larger than that for \lra,
indicates $4f$-originating quasiparticle mass enhancement. Magnetic
susceptibility $\chi(T)$ indicates that the CEF ground state is a $\Gamma_1$
singlet and a $\Gamma_4^{(1)}$ triplet first excited state lies at $\Delta_{\rm
CEF}\sim 30$ K above. Systematic comparison among \pos, \prs, \pra and La-based
reference compounds suggests that inelastic exchange- and
aspherical-charge-scatterings of conduction electrons from CEF-split $4f$
levels play an essential role for the quasiparticle mass enhancement and the
value of $T_{\rm c}$ in the Pr-based filled skutterudites.


title:
The prospects for constraining dark energy with future X-ray cluster gas
  mass fraction measurements

abstract:
  We examine the ability of a future X-ray observatory to constrain dark energy
via measurements of the cluster X-ray gas mass fraction, fgas. We find that
fgas measurements for a sample of ~500 hot, X-ray bright, dynamically relaxed
clusters, to a precision of ~5 per cent, can be used to constrain dark energy
with a Dark Energy Task Force (DETF) figure of merit of 15-40, with the
possibility of boosting these values by 40 per cent or more by optimizing the
redshift distribution of target clusters. Such constraints are comparable to
those predicted by the DETF for other leading, planned dark energy experiments.
A future fgas experiment will be preceded by a large X-ray or SZ survey that
will find hot, X-ray luminous clusters out to high redshifts. Short `snapshot'
observations with the new X-ray observatory should then be able to identify a
sample of ~500 suitably relaxed systems. The redshift, temperature and X-ray
luminosity range of interest has already been partially probed by existing
X-ray cluster surveys which allow reasonable estimates of the fraction of
clusters that will be suitably relaxed for fgas work. Our analysis uses a
Markov Chain Monte Carlo method which fully captures the relevant degeneracies
between parameters and facilitates the incorporation of priors and systematic
uncertainties in the analysis. We explore the effects of such uncertainties for
scenarios ranging from optimistic to pessimistic. We conclude that the fgas
experiment will provide tight constraints on the mean matter and dark energy
densities, with a peak sensitivity for dark energy work at redshifts midway
between those of supernovae and baryon acoustic oscillation/weak
lensing/cluster number counts experiments. In combination, these experiments
should enable a precise measurement of the evolution of dark energy. (Abridged)


title:
Comparative Analysis of Non-thermal Emissions and Study of Electron
  Transport in a Solar Flare

abstract:
  We study the non-thermal emissions in a solar flare occurring on 2003 May 29
by using RHESSI hard X-ray (HXR) and Nobeyama microwave observations. This
flare shows several typical behaviors of the HXR and microwave emissions: time
delay of microwave peaks relative to HXR peaks, loop-top microwave and
footpoint HXR sources, and a harder electron energy distribution inferred from
the microwave spectrum than from the HXR spectrum. In addition, we found that
the time profile of the spectral index of the higher-energy ($\gsim 100$ keV)
HXRs is similar to that of the microwaves, and is delayed from that of the
lower-energy ($\lsim 100$ keV) HXRs. We interpret these observations in terms
of an electron transport model called {\TPP}. We numerically solved the
spatially-homogeneous {\FP} equation to determine electron evolution in energy
and pitch-angle space. By comparing the behaviors of the HXR and microwave
emissions predicted by the model with the observations, we discuss the
pitch-angle distribution of the electrons injected into the flare site. We
found that the observed spectral variations can qualitatively be explained if
the injected electrons have a pitch-angle distribution concentrated
perpendicular to the magnetic field lines rather than isotropic distribution.


title: Overlapping self-affine sets of Kakeya type

abstract:
  We compute the Minkowski dimension for a family of self-affine sets on the
plane. Our result holds for every (rather than generic) set in the class.
Moreover, we exhibit explicit open subsets of this class where we allow
overlapping, and do not impose any conditions on the norms of the linear maps.
The family under consideration was inspired by the theory of Kakeya sets.


title:
Tongue-placed tactile biofeedback suppresses the deleterious effects of
  muscle fatigue on joint position sense at the ankle

abstract:
  Whereas the acuity of the position sense at the ankle can be disturbed by
muscle fatigue, it recently also has been shown to be improved, under normal
ankle neuromuscular state, through the use of an artificial tongue-placed
tactile biofeedback. The underlying principle of this biofeedback consisted of
supplying individuals with supplementary information about the position of
their matching ankle position relative to their reference ankle position
through electrotactile stimulation of the tongue. Within this context, the
purpose of the present experiment was to investigate whether this biofeedback
could mitigate the deleterious effect of muscle fatigue on joint position sense
at the ankle. To address this objective, sixteen young healthy university
students were asked to perform an active ankle-matching task in two conditions
of No-fatigue and Fatigue of the ankle muscles and two conditions of
No-biofeedback and Biofeedback. Measures of the overall accuracy and the
variability of the positioning were determined using the absolute error and the
variable error, respectively. Results showed that the availability of the
biofeedback allowed the subjects to suppress the deleterious effects of muscle
fatigue on joint position sense at the ankle. In the context of sensory
re-weighting process, these findings suggested that the central nervous system
was able to integrate and increase the relative contribution of the artificial
tongue-placed tactile biofeedback to compensate for a proprioceptive
degradation at the ankle.


title: A note on the two-neutrino decay mode of excited nuclear states

abstract:
  The possibility for the excited nuclear states to decay by emission of the
neutrino-antineutrino pair in direct competition with electromagnetic decay
modes is commented upon.


title: Evolution of the genetic code from the GC- to the AGUC-alphabet

abstract:
  A hypothesis of the evolution of the genetic code is proposed, the leading
mechanism of which is the nucleotide spontaneous damage leading to
AT-enrichment of the genome. The hypothesis accounts for stability of the
genetic code towards point mutations, the presence of code dialects, and the
symmetry of the genetic code table.


title: The Detector DCR

abstract:
  The Detector Concept Report (DCR) consists of two parts, one for the physics
and the other for ILC detectors. It has been prepared as the accompany document
of the ILC Accelerator Reference Design Report. The detector DCR describes ILC
detector designs, R&Ds on detector technologies and expected performances. The
overview of the Detector DCR and the plan for the final release are presented.


title:
Permutation statistics related to a class of noncommutative symmetric
  functions and generalizations of the Genocchi numbers

abstract:
  We prove conjectures of the third author [L. Tevlin, Proc. FPSAC'07, Tianjin]
on two new bases of noncommutative symmetric functions: the transition matrices
from the ribbon basis have nonnegative integral coefficients. This is done by
means of two composition-valued statistics on permutations and packed words,
which generalize the combinatorics of Genocchi numbers.


title: Differential Complexes and Stratified Pro-Modules

abstract:
  In this paper we introduce the category of stratified Pro-modules and the
notion of induced object in this category. We propose a translation of a
Morihiko Saito equivalence result using the dual language of Pro-objects. So we
prove an equivalence between the derived category of stratified Pro-modules and
the category of Pro-differential complexes. We also supply a comparison with
the notion of Crystal in Pro-module (introduced by P. Deligne in 1960).


title: Gravitino dark matter from increased thermal relic particles

abstract:
  We investigate the so-called superWIMP scenario with gravitino as the
lightest supersymmetric particle (LSP) in the context of non-standard
cosmology, in particular, brane world cosmology. As a candidate of the
next-to-LSP (NLSP), we examine slepton and sneutrino. Brane world cosmological
effects dramatically enhance the relic density of the slepton or sneutrino
NLSP, so that the NLSP with mass of order 100 GeV can provide the correct
abundance of gravitino dark matter through its decay. We find that with an
appropriate five dimensional Planck mass, this scenario can be realized
consistently with the constraints from Big Bang Nucleosynthesis (BBN) for both
NLSP candidates of slepton and sneutrino. The BBN constraints for slepton NLSP
are more stringent than that for sneutrino, as the result, the gravitino must
be rather warm in the slepton NLSP case. The energy density of gravitino
produced by thermal scattering is highly suppressed and negligible due to the
brane world cosmological effects.


title: Geometric phases in open tripod systems

abstract:
  We first consider stimulated Raman adibatic passages (STIRAP) in a closed
four-level tripod system. In this case, the adiabatic eigenstates of the system
acquire real geometric phases. When the system is open and subject to
decoherence they acquire complex geometric phases that we determine by a Monte
Carlo wave function approach. We calculate the geometric phases and the state
evolution in the closed as well as in the open system cases and describe the
deviation between these in terms of the phases acquired. When the system is
closed, the adiabatic evolution implements a Hadamard gate. The open system
implements an imperfect gate and hence has a fidelity below unity. We express
this fidelity in terms of the acquired geometric phases.


title:
Low temperature magnetization of the S=1/2 kagome antiferromagnet
  ZnCu_3(OH)_6Cl_2

abstract:
  The dc-magnetization of the unique S=1/2 kagome antiferromagnet
Herbertsmithite has been measured down to 0.1K. No sign of spin freezing is
observed in agreement with former muSR and ac-susceptibility results. The low
temperature magnetic response is dominated by a defect contribution which
exhibits a new energy scale $\simeq 1$ K, likely reflecting the coupling of the
defects. The defect component is saturated at low temperature by H>8T applied
magnetic fields which enables us to estimate an upper bound for the non
saturated intrinsic kagome susceptibility at T=1.7K.


title:
Low energy properties of the SU(m|n) supersymmetric Haldane-Shastry spin
  chain

abstract:
  The ground state and low energy excitations of the SU(m|n) supersymmetric
Haldane-Shastry spin chain are analyzed. In the thermodynamic limit, it is
found that the ground state degeneracy is finite only for the SU(m|0) and
SU(m|1) spin chains, while the dispersion relation for the low energy and low
momentum excitations is linear for all values of m and n. We show that the low
energy excitations of the SU(m|1) spin chain are described by a conformal field
theory of m non-interacting Dirac fermions which have only positive energies;
the central charge of this theory is m/2. Finally, for n \ge 1, the partition
functions of the SU(m|n) Haldane-Shastry spin chain and the SU(m|n)
Polychronakos spin chain are shown to be related in a simple way in the
thermodynamic limit at low temperatures.


title: Higher-spin Gauge and Trace Anomalies in Two-dimensional Backgrounds

abstract:
  Two-dimensional quantum fields in electric and gravitational backgrounds can
be described by conformal field theories, and hence all the physical
(covariant) quantities can be written in terms of the corresponding holomorphic
quantities. In this paper, we first derive relations between covariant and
holomorphic forms of higher-spin currents in these backgrounds, and then, by
using these relations, obtain higher-spin generalizations of the trace and
gauge (or gravitational) anomalies up to spin 4. These results are applied to
derive higher-moments of Hawking fluxes in black holes in a separate paper
arXiv:0710.0456.


title: Search for two photon exchange from $e^+ +e^-\to p+\bar p +\gamma$ data

abstract:
  We look for asymmetries in the angular distributions of events from recent
data on $e^+ +e^-\to p +\bar p +\gamma$ from BABAR collaboration. From first
principles, as the C-invariance of the electromagnetic interaction and the
crossing symmetry, the presence of two-photon exchange would create a forward
backward asymmetry in the data. The analysis of the available data shows no
asymmetry, within an error of 2%. This result is consistent with a
structureless model for the proton, based on a calculation of $e^+ +e^-\to
\mu^+ + \mu^- +\gamma$ with a proper replacement of the muon mass. As no
systematic deviations are seen, we can conclude that these data do not give any
hint of the presence of the two photon contribution, in all the considered
kinematical range.


title: Adjoint zero-modes as a tool to understand the Yang-Mills vacuum

abstract:
  The use of adjoint (quasi) zero-modes of the Dirac operator to probe the
Yangs-Mills vacuum has been recently advocated by Gonzalez-Arroyo and Kirchner.
The construction relies on the use of the super-symmetric zero mode which, for
classical configurations, provides a direct estimate of the gauge action
density. In the lattice implementation of this idea, we show how the results
improve considerably if the overlap operator is used instead of the
Wilson-Dirac one. Before proceeding to the detailed study of Monte Carlo
ensembles, we studied here a series of potentially complicated situations which
can be encountered. In particular, we study the case of instanton
anti-instanton pairs and analyse how the results depend upon separation. The
effect of lattice artifacts is also of concern. Indeed, a statistical analysis
of zero modes of thermalised SU(2) configurations at beta=2.57 shows a
significant fraction having 4N+2 adjoint zero modes, in contradiction with the
index theorem. This violation must be associated to the roughness of the
lattice configurations. Indeed, we show that this situation occurs for
instantons of size of the order of the lattice spacing.


title: Hawking Radiation via Higher-spin Gauge Anomalies

abstract:
  We give a higher-spin generalization of the anomaly method for the Hawking
radiation from black holes. In the paper arXiv:0710.0453 higher-spin
generalizations of the gauge (and gravitational) anomalies in d=2 were
obtained. By applying these anomalies to black hole physics, we derive the
higher moments of the Hawking fluxes. We also give a higher-spin generalization
of the trace anomaly method by Christensen and Fulling.


title: Conditional observability versus self-duality in a schematic model

abstract:
  In a simple PT-symmetric model we demonstrate that and how the violation of a
reflection symmetry $E_j=-E_{N+1-j}$ of the spectrum (called "self-duality" by
Dunne and Shifman) is connected with the loss of the simplicity of the shape of
the boundary of the domain D of parameters where the Hamiltonian H is
quasi-Hermitian, i.e., where all the bound-state energies are real.


title: An alternative heavy Higgs mass limit

abstract:
  After commenting on the present value of the Higgs particle mass from
radiative corrections, we explore the phenomenological implications of an
alternative, non-perturbative renormalization of the scalar sector where the
mass of the Higgs particle does not represent a measure of observable
interactions at the Higgs mass scale. In this approach the Higgs particle could
be very heavy, even heavier than 1 TeV, and remain nevertheless a relatively
narrow resonance.


title: Statistical properties of agent-based market area model

abstract:
  One dimensional stylized model taking into account spatial activity of firms
with uniformly distributed customers is proposed. The spatial selling area of
each firm is defined by a short interval cut out from selling space (large
interval). In this representation, the firm size is directly associated with
the size of its selling interval.
  The recursive synchronous dynamics of economic evolution is discussed where
the growth rate is proportional to the firm size incremented by the term
including the overlap of the selling area with areas of competing firms. Other
words, the overlap of selling areas inherently generate a negative feedback
originated from the pattern of demand. Numerical simulations focused on the
obtaining of the firm size distributions uncovered that the range of free
parameters where the Pareto's law holds corresponds to the range for which the
pair correlation between the nearest neighbor firms attains its minimum.


title:
Convergence of simple random walks on random discrete trees to Brownian
  motion on the continuum random tree

abstract:
  In this article it is shown that the Brownian motion on the continuum random
tree is the scaling limit of the simple random walks on any family of discrete
$n$-vertex ordered graph trees whose search-depth functions converge to the
Brownian excursion as $n\to\infty$. We prove both a quenched version (for
typical realisations of the trees) and an annealed version (averaged over all
realisations of the trees) of our main result. The assumptions of the article
cover the important example of simple random walks on the trees generated by
the Galton-Watson branching process, conditioned on the total population size.


title: Momentum of an electromagnetic wave in dielectric media

abstract:
  Almost a hundred years ago, two different expressions were proposed for the
energy--momentum tensor of an electromagnetic wave in a dielectric. Minkowski's
tensor predicted an increase in the linear momentum of the wave on entering a
dielectric medium, whereas Abraham's tensor predicted its decrease. Theoretical
arguments were advanced in favour of both sides, and experiments proved
incapable of distinguishing between the two. Yet more forms were proposed, each
with their advocates who considered the form that they were proposing to be the
one true tensor. This paper reviews the debate and its eventual conclusion:
that no electromagnetic wave energy--momentum tensor is complete on its own.
When the appropriate accompanying energy--momentum tensor for the material
medium is also considered, experimental predictions of all the various proposed
tensors will always be the same, and the preferred form is therefore
effectively a matter of personal choice.


title: B_K with dynamical overlap fermions

abstract:
  We report on a calculation of $B_K$ with two-flavor dynamical overlap
fermions on a $16^3 \times 32$ lattice at $a\sim 0.12$ fm. The results are
compared with the PQChPT prediction of quark mass dependence. The systematic
errors due to finite volume effects and fixing topology are discussed.


title:
Ground-state phase diagram and magnetic properties of a tetramerized
  spin-1/2 J_1-J_2 model: BEC of bound magnons and absence of the transverse
  magnetization

abstract:
  We study the ground state and the magnetization process of a spin-1/2
$J_1$-$J_2$ model with a plaquette structure by using various methods. For
small inter-plaquette interaction, this model is expected to have a spin-gap
and we computed the first- and the second excitation energies. If the gap of
the lowest excitation closes, the corresponding particle condenses to form
magnetic orders. By analyzing the quintet gap and magnetic interactions among
the quintet excitations, we find a spin-nematic phase around $J_1/J_2\sim -2$
due to the strong frustration and the quantum effect. When high magnetic moment
is applied, not the spin-1 excitations but the spin-2 ones soften and dictate
the magnetization process. We apply a mean-field approximation to the effective
Hamiltonian to find three different types of phases (a conventional BEC phase,
``striped'' supersolid phases and a 1/2-plateau). Unlike the BEC in spin-dimer
systems, this BEC phase is not accompanied by transverse magnetization.
Possible connection to the recently discovered spin-gap compound (CuCl)LaNb2O7
is discussed.


title: Human proofs of identities by Osburn and Schneider

abstract:
  Osburn and Schneider derived several combinatorial identities involving
harmonic numbers using the computer programm Sigma. Here, they are derived by
partial fraction decomposition and creative telescoping.


title:
The Loudest Event Statistic: General Formulation, Properties and
  Applications

abstract:
  The use of the loudest observed event to generate statistical statements
about rate and strength has become standard in searches for gravitational waves
from compact binaries and pulsars. The Bayesian formulation of the method is
generalized in this paper to allow for uncertainties both in the background
estimate and in the properties of the population being constrained. The method
is also extended to allow rate interval construction. Finally, it is shown how
to combine the results from multiple experiments and a comparison is drawn
between the upper limit obtained in a single search and the upper limit
obtained by combining the results of two experiments each of half the original
duration. To illustrate this, we look at an example case, motivated by the
search for gravitational waves from binary inspiral.


title: Measurement of beta in B decays to charm and charmonium in BABAR

abstract:
  In this article we will review recent BABAR measurements of Unitarity
Triangle angle beta in B meson decays to charm and charmonium.


title:
Inelastically generated solitons and anti-solitons in the perturbed KdV
  equation

abstract:
  Under the effect of common perturbations, the multiple-soliton solution of
the KdV equation is transformed into a sum of an elastic and a first-order
inelastic component. The elastic component is a perturbation series, identical
in structure to the perturbed single-soliton solution. It preserves the
soliton-scattering picture. The inelastic component is generated by
perturbation terms that represent coupling between KdV solitons and
inelastically generated soliton-anti-soliton waves. It asymptotes into solitons
and anti-solitons, that evolve along the characteristic lines of the KdV
solitons. This is demonstrated in the two-soliton case.


title: Elements of Group Theory

abstract:
  \noindent 1. Generalities\hfil\break 2. Lie groups and Lie
algebras\hfil\break
  3. The unitary groups\hfil\break
  4. Representations of the SU(n) groups (and of their algebras)\hfil\break
  5. The tensor method for unitary groups, and\hb the permutation
group\hfil\break
  6. Relativistic invariance. The Lorentz group\hfil\break
  7. General representation of relativistic states