title:
Molecular line profiles as diagnostics of protostellar collapse:
  modelling the `blue asymmetry' in inside-out infall

abstract:
  The evolution of star-forming core analogues undergoing inside-out collapse
is studied with a multi-point chemodynamical model which self-consistently
computes the abundance distribution of chemical species in the core. For
several collapse periods the output chemistry of infall tracer species such as
HCO+, CS, and N2H+, is then coupled to an accelerated Lambda-iteration
radiative transfer code, which predicts the emerging molecular line profiles
using two different input gas/dust temperature distributions. We investigate
the sensitivity of the predicted spectral line profiles and line asymmetry
ratios to the core temperature distribution, the time-dependent model
chemistry, as well as to ad hoc abundance distributions. The line asymmetry is
found to be strongly dependent on the adopted chemical abundance distribution.
In general, models with a warm central region show higher values of blue
asymmetry in optically thick HCO+ and CS lines than models with a starless core
temperature profile. We find that in the formal context of Shu-type inside-out
infall, and in the absence of rotation or outflows, the relative blue asymmetry
of certain HCO+ and CS transitions is a function of time and, subject to the
foregoing caveats, can act as a collapse chronometer. The sensitivity of
simulated HCO+ line profiles to linear radial variations, subsonic or
supersonic, of the internal turbulence field is investigated in the separate
case of static cores.


title: Spectral stability of weak relaxation shock profiles

abstract:
  Using a combination of Kawashima- and Goodman-type energy estimates, we
establish spectral stability of general small-amplitude relaxation shocks of
symmetric dissipative systems. This extends previous results obtained by Plaza
and Zumbrun by singular perturbation techniques under an additional technical
assumption, namely, that the background equation be noncharacteristic with
respect to the shock.


title: Three-nucleon interactions: dynamics

abstract:
  A discussion is presented of the dynamics underlying three-body nuclear
forces, with emphasis on changes which occurred over several decades.


title:
On the deflection of light by topological defects in nematic liquid
  crystals

abstract:
  The influence of controlable parameters like temperature and wavelength on
the trajectories of light in a nematic liquid crystal with topological defects
is studied through a geometric model. The model incorporates phenomenological
details as how the refractive indices depend on such parameters. The deflection
of light by the topological defect is then shown to be greater at lower
temperatures and shorter wavelengths.


title: New lattice action for heavy quarks

abstract:
  We extend the Fermilab method for heavy quarks to include interactions of
dimensions 6 and 7 in the action. There are, in general, many new interactions,
but we carry out the calculations needed to match the lattice action to
continuum QCD at the tree level, finding six non-zero couplings. Using the
heavy-quark theory of cutoff effects, we estimate how large the remaining
discretization errors are. We find that our tree-level matching, augmented with
one-loop matching of the dimension-five interactions, can bring these errors
below 1%, at currently available lattice spacings.


title:
Average performance of the sparsest approximation using a general
  dictionary

abstract:
  We consider the minimization of the number of non-zero coefficients (the
$\ell_0$ "norm") of the representation of a data set in terms of a dictionary
under a fidelity constraint. (Both the dictionary and the norm defining the
constraint are arbitrary.) This (nonconvex) optimization problem naturally
leads to the sparsest representations, compared with other functionals instead
of the $\ell_0$ "norm". Our goal is to measure the sets of data yielding a
$K$-sparse solution--i.e. involving $K$ non-zero components. Data are assumed
uniformly distributed on a domain defined by any norm--to be chosen by the
user. A precise description of these sets of data is given and relevant bounds
on the Lebesgue measure of these sets are derived. They naturally lead to bound
the probability of getting a $K$-sparse solution. We also express the
expectation of the number of non-zero components. We further specify these
results in the case of the Euclidean norm, the dictionary being arbitrary.


title:
An EM algorithm for estimation in the Mixture Transition Distribution
  model

abstract:
  The Mixture Transition Distribution (MTD) model was introduced by Raftery to
face the need for parsimony in the modeling of high-order Markov chains in
discrete time. The particularity of this model comes from the fact that the
effect of each lag upon the present is considered separately and additively, so
that the number of parameters required is drastically reduced. However, the
efficiency for the MTD parameter estimations proposed up to date still remains
problematic on account of the large number of constraints on the parameters. In
this paper, an iterative procedure, commonly known as Expectation-Maximization
(EM) algorithm, is developed cooperating with the principle of Maximum
Likelihood Estimation (MLE) to estimate the MTD parameters. Some applications
of modeling MTD show the proposed EM algorithm is easier to be used than the
algorithm developed by Berchtold. Moreover, the EM Estimations of parameters
for high-order MTD models led on DNA sequences outperform the corresponding
fully parametrized Markov chain in terms of Bayesian Information Criterion. A
software implementation of our algorithm is available in the library seq++ at
http://stat.genopole.cnrs.fr/seqpp


title: Quintics with Finite Simple Symmetries

abstract:
  We construct all quintic invariants in five variables with simple Non-Abelian
finite symmetry groups. These define Calabi-Yau three-folds which are left
invariant by the action of A_5, A_6 or PSL_2(11).


title:
Time-Energy Uncertainty Relations for Neutrino Oscillation and
  M\"Ossbauer Neutrino Experiment

abstract:
  Using the Mandelstam-Tamm method we derive time-energy uncertainty relations
for neutrino oscillations. We demonstrate that the small energy uncertainty of
antineutrinos in a recently considered experiment with recoilless resonant
(M\"ossbauer) production and absorption of tritium antineutrinos is in conflict
with the energy uncertainty which, according to the time-energy uncertainty
relation, is necessary for neutrino oscillations to happen. A M\"ossbauer
neutrino experiment could provide a unique possibility to test the
applicability of the time-energy uncertainty relation to neutrino oscillations
and to reveal the true nature of neutrino oscillations.


title:
Une approche modulaire probabiliste pour le routage \`a Qualit\'e de
  Service int\'egr\'ee

abstract:
  Due to emerging real-time and multimedia applications, efficient routing of
information packets in dynamically changing communication network requires that
as the load levels, traffic patterns and topology of the network change, the
routing policy also adapts. We focused in this paper on QoS based routing by
developing a neuro-dynamic programming to construct dynamic state dependent
routing policies. We propose an approach based on adaptive algorithm for packet
routing using reinforcement learning which optimizes two criteria: cumulative
cost path and end-to-end delay. Numerical results obtained with OPNET simulator
for different packet interarrival times statistical distributions with
different levels of traffic's load show that the proposed approach gives better
results compared to standard optimal path routing algorithms.


title:
Evaluation and exploitation of knowledge robustness in knowledge-based
  systems

abstract:
  Industrial knowledge is complex, difficult to formalize and very dynamic in
reason of the continuous development of techniques and technologies. The
verification of the validity of the knowledge base at the time of its
elaboration is not sufficient. To be exploitable, this knowledge must then be
able to be used under conditions (slightly) different from the conditions in
which it was formalized. So, it becomes vital for the company to permanently
evaluate the quality of the industrial knowledge implemented in the system.
This evaluation is founded on the concept of robustness of the knowledge
formalized by conceptual graphs. The evaluation method is supported by a
computerized tool.


title:
Reply to Comment on "Drip Paintings and Fractal Analysis" by Micolich et
  al (arXiv:0712.165v1 [cond-mat.stat-mech])

abstract:
  We reply to the comment of Micolich et al and demonstrate that their
criticisms are unfounded. In particular we provide a detailed discussion of our
box-counting algorithm and of the interpretation of multi-layered paintings. We
point out that in their entire body of work, Taylor et al have not provided the
scientific community with sufficient empirical support of their claims, nor
have they adequately addressed any of the problems we have identified with the
application of fractal analysis to drip paintings.


title: The SuperNova Early Warning System

abstract:
  A core collapse in the Milky Way will produce an enormous burst of neutrinos
in detectors world-wide. Such a burst has the potential to provide an early
warning of a supernova's appearance. I will describe the nature of the signal,
the sensitivity of current detectors, and SNEWS, the SuperNova Early Warning
System, a network designed to alert astronomers as soon as possible after the
detected neutrino signal.


title: Magnetism in Herbig Ae/Be stars and the link to the Ap/Bp stars

abstract:
  Among the A/B stars, about 5% host large-scale organised magnetic fields.
These magnetic stars show also abundance anomalies in their spectra, and are
therefore called the magnetic Ap/Bp stars. Most of these stars are also slow
rotators compared to the normal A and B stars. Today, one of the greatest
challenges concerning the Ap/Bp stars is to understand the origin of their slow
rotation and their magnetic fields. The favoured hypothesis for the latter is
that the fields are fosils, which implies that the magnetic fields subsist
throughout the different evolutionary phases, and in particular during the
pre-main sequence phase. The existence of magnetic fields at the pre-main
sequence phase is also required to explain the slow rotation of Ap/Bp stars.
During the last 3 years we performed a spectropolarimetric survey of the Herbig
Ae/Be stars in the field and in young clusters, in order to investigate their
magnetism and rotation. These investigations have resulted in the detection
and/or confirmation of magnetic fields in 8 Herbig Ae/Be stars, ranging in mass
from 2 to nearly 15 solar masses. In this paper I will present the results of
our survey, as well as their implications for the origin and evolution of the
magnetic fields and rotation of the A and B stars.


title: Ground State Energy of Dilute Bose Gas in Small Negative Potential Case

abstract:
  It is well known that the ground state energy of a three dimensional dilute
Bose gas in the thermodynamic limit is $E=4\pi a \rho N$ when the particles
interact via a non-negative, finite range, symmetric, two-body potential. Here,
$N$ is the number of particles, $\rho$ is the density of the gas, and $a$ is
the scattering length of the potential. In this paper, we prove the same result
without the non-negativity condition on the potential, provided the negative
part is small.


title:
Formulas for primitive Idempotents in Frobenius Algebras and an
  Application to Decomposition maps

abstract:
  In the first part of this paper we present explicit formulas for primitive
idempotents in arbitrary Frobenius algebras using the entries of representing
matrices coming from projective indecomposable modules with respect to a
certain choice of basis. The proofs use a generalisation of the well known
Frobenius-Schur relations for semisimple algebras.
  The second part of this paper considers $\Oh$-free $\Oh$-algebras of finite
$\Oh$-rank over a discrete valuation ring $\Oh$ and their decomposition maps
under modular reduction modulo the maximal ideal of $\Oh$, thereby studying the
modular representation theory of such algebras.
  Using the formulas from the first part we derive general criteria for such a
decomposition map to be an isomorphism that preserves the classes of simple
modules involving explicitly known matrix representations on projective
indecomposable modules.
  Finally we show how this approach could eventually be used to attack a
conjecture by Gordon James in the formulation of Meinolf Geck for
Iwahori-Hecke-Algebras, provided the necessary matrix representations on
projective indecomposable modules could be constructed explicitly.


title: Quantum Markovian activated surface diffusion of interacting adsorbates

abstract:
  A quantum Markovian activated atom-surface diffusion model with interacting
adsorbates is proposed for the intermediate scattering function, which is shown
to be complex-valued and factorizable into a classical-like and a
quantum-mechanical factor. Applications to the diffusion of Na atoms on flat
(weakly corrugated) and corrugated-Cu(001) surfaces at different coverages and
surface temperatures are analyzed. Quantum effects are relevant to diffusion at
low surface temperatures and coverages even for relatively heavy particles,
such as Na atoms, where transport by tunneling is absent.


title:
Solitons as baryons and qualitons as constituent quarks in
  two-dimensional QCD

abstract:
  We study the soliton type solutions arising in two-dimensional quantum
chromodynamics (QCD$_{2}$). The so-called generalized sine-Gordon model (GSG)
arises as the low-energy effective action of bosonized QCD$_{2}$ for unequal
quark mass parameters, and it has been shown that the relevant solitons
describe the normal and exotic baryonic spectrum of QCD$_{2}$
[JHEP(03)(2007)(055)]. In the first part of this chapter we classify the
soliton and kink type solutions of the sl(3) GSG model. Related to the GSG
model we consider the sl(3) affine Toda model coupled to matter fields (Dirac
spinors)
  (ATM). It has been shown the confinement of the spinors inside the solitons
and kinks of the GSG model providing an extended hadron model for "quark"
confinement [JHEP(01)(2007)(027)]. In the second part of this chapter we
discuss the appearance of the constituent quarks in the context of bosonized
QCD$_{2}$ and the relevance of the $sl(2)$ ATM model in order to describe the
confinement of the color degrees of freedom. We have shown that QCD$_{2}$ has
quark soliton solutions if the quark mass is sufficiently large.


title: A predictive formulation of the Nambu--Jona-Lasinio model

abstract:
  A novel strategy to handle divergences typical of perturbative calculations
is implemented for the Nambu--Jona-Lasinio model and its phenomenological
consequences investigated. The central idea of the method is to avoid the
critical step involved in the regularization process, namely the explicit
evaluation of divergent integrals. This goal is achieved by assuming a
regularization distribution in an implicit way and making use, in intermediary
steps, only of very general properties of such regularization. The finite parts
are separated of the divergent ones and integrated free from effects of the
regularization. The divergent parts are organized in terms of standard objects
which are independent of the (arbitrary) momenta running in internal lines of
loop graphs. Through the analysis of symmetry relations, a set of properties
for the divergent objects are identified, which we denominate consistency
relations, reducing the number of divergent objects to only a few ones. The
calculational strategy eliminates unphysical dependencies of the arbitrary
choices for the routing of internal momenta, leading to ambiguity-free, and
symmetry-preserving physical amplitudes. We show that the imposition of scale
properties for the basic divergent objects leads to a critical condition for
the constituent quark mass such that the remaining arbitrariness is removed.
The model become predictive in the sense that its phenomenological consequences
do not depend on possible choices made in intermediary steps. Numerical results
are obtained for physical quantities at the one-loop level for the pion and
sigma masses and pion-quark and sigma-quark coupling constants.


title:
A note on the Cops & Robber game on graphs embedded in non-orientable
  surfaces

abstract:
  The Cops and Robber game is played on undirected finite graphs. A number of
cops and one robber are positioned on vertices and take turns in sliding along
edges. The cops win if they can catch the robber. The minimum number of cops
needed to win on a graph is called its cop number. It is known that the cop
number of a graph embedded on a surface $X$ of genus $g$ is at most $3g/2 + 3$,
if $X$ is orientable (Schroeder 2004), and at most $2g+1$, otherwise
(Nowakowski & Schroeder 1997).
  We improve the bounds for non-orientable surfaces by reduction to the
orientable case using covering spaces.
  As corollaries, using Schroeder's results, we obtain the following: the
maximum cop number of graphs embeddable in the projective plane is 3; the cop
number of graphs embeddable in the Klein Bottle is at most 4, and an upper
bound is $3g/2 + 3/2$ for all other $g$.


title: The abelianization of the level L mapping class group

abstract:
  We calculate the abelianizations of the level $L$ subgroup of the genus $g$
mapping class group and the level $L$ congruence subgroup of the $2g \times 2g$
symplectic group for $L$ odd and $g \geq 3$.


title:
The thermonuclear rate for the 19F(a,p)22Ne reaction at stellar
  temperatures

abstract:
  The $^{19}$F($\alpha$,p)$^{22}$Ne reaction is considered to be one of the
main sources of fluorine depletion in AGB and Wolf-Rayet stars. The reaction
rate still retains large uncertainties due to the lack of experimental studies
available. In this work the yields for both exit channels to the ground state
and first excited state of $^{22}$Ne have been measured and several previously
unobserved resonances have been found in the energy range E$_{lab}$=792-1993
keV. The level parameters have been determined through a detailed R-matrix
analysis of the reaction data and a new reaction rate is provided on the basis
of the available experimental information.


title: Entanglement Dynamics in a Dispersively Coupled Qubit-Oscillator System

abstract:
  We study entanglement dynamics in a system consisting of a qubit dispersively
coupled to a finite-temperature, dissipative, driven oscillator. We show that
there are two generic ways to generate entanglement: one can entangle the qubit
either with the phase or the amplitude of the oscillator's motion. Using an
exact solution of the relevant quantum master equation, we study the robustness
of both these kinds of entanglement against the effects of dissipation and
temperature; in the limit of zero temperature (but finite damping), a simple
analytic expression is derived for the logarithmic negativity. We also discuss
how the generated entanglement may be detected via dephasing revivals, being
mindful that revivals can occur even in the absence of any useful entanglement.
Our results have relevance to quantum electromechanics, as well as to circuit
QED systems.


title:
Local semicircle law and complete delocalization for Wigner random
  matrices

abstract:
  We consider $N\times N$ Hermitian random matrices with independent identical
distributed entries. The matrix is normalized so that the average spacing
between consecutive eigenvalues is of order 1/N. Under suitable assumptions on
the distribution of the single matrix element, we prove that, away from the
spectral edges, the density of eigenvalues concentrates around the Wigner
semicircle law on energy scales $\eta \gg N^{-1} (\log N)^8$. Up to the
logarithmic factor, this is the smallest energy scale for which the semicircle
law may be valid. We also prove that for all eigenvalues away from the spectral
edges, the $\ell^\infty$-norm of the corresponding eigenvectors is of order
$O(N^{-1/2})$, modulo logarithmic corrections. The upper bound $O(N^{-1/2})$
implies that every eigenvector is completely delocalized, i.e., the maximum
size of the components of the eigenvector is of the same order as their average
size. In the Appendix, we include a lemma by J. Bourgain which removes one of
our assumptions on the distribution of the matrix elements.


title:
The influence of gas expulsion and initial mass-segregation on the
  stellar mass-function of globular star clusters

abstract:
  Recently de Marchi, Paresce & Pulone (2007) studied a sample of twenty
globular clusters and found that all clusters with high concentrations have
steep stellar mass-functions while clusters with low concentration have
comparatively shallow mass-functions. No globular clusters were found with a
flat mass-function and high concentration. This seems curious since more
concentrated star clusters are believed to be dynamically more evolved and
should have lost more low-mass stars via evaporation, which would result in a
shallower mass-function in the low-mass part.
  We show that this effect can be explained by residual-gas expulsion from
initially mass-segregated star clusters, and is enhanced further through
unresolved binaries. If gas expulsion is the correct mechanism to produce the
observed trend, then observation of these parameters would allow to constrain
cluster starting conditions such as star formation efficiency and the
time-scale of gas expulsion.


title:
Discovery of a T Dwarf Binary with the Largest Known J-Band Flux
  Reversal

abstract:
  We present Keck laser guide star observations of two T2.5 dwarfs - 2MASS
J11061197+2754225 & 2MASS J14044941-3159329 - using NIRC2 on Keck-II and find
2MASS J14044941-3159329 to be a 0.13" binary. This system has a secondary that
is 0.45 mags brighter than the primary in J-band but 0.49 mags fainter in
H-band and 1.13 mags fainter in Ks-band. We use this relative photometry along
with near-infrared synthetic modeling performed on the integrated light
spectrum to derive component types of T1 for the primary and T5 for the
secondary. Optical spectroscopy of this system obtained with Magellan/LDSS-3 is
also presented. This is the fourth L/T transition binary to show a flux
reversal in the 1-1.2 micron regime and this one has the largest flux reversal.
Unless the secondary is itself an unresolved binary, the J-band magnitude
difference between the secondary and primary shows that the J-band "bump" is
indeed a real feature and not an artifact caused by unresolved binarity.


title: Merger and Ring Galaxy Formation Rates at z<=2

abstract:
  We compare the observed merger rate of galaxies over cosmic time and the
frequency of collisional ring galaxies (CRGs), with analytic models and halo
merger and collision rates from a large cosmological simulation. In the Lambda
cold dark matter (LCDM) model we find that the cosmic {\it merger fraction}
does not evolve strongly between 0.2<z<2, implying that the observed decrease
of the cosmic star formation rate since z~1 might not be tied to a disappearing
population of major mergers. Halos hosting massive galaxies undergo on average
~2 mergers from z~2 up to present day, reflecting the late assembly time for
the massive systems and the related downsizing problem. The cosmic {\it merger
rate} declines with redshift: at the present time it is a factor of 10 lower
than at z~2, in reasonable agreement with the current available data. The rate
of CRG formation derived from the interactions between halo progenitors up to
z=2 is found to be a good tracer of the cosmic merger rate. In the LCDM model
the rate of CRGs as well as the merger rate do not scale as (1+z)^m, as
suggested by previous models. Our predictions of cosmic merger and CRG rates
may be applied to forthcoming surveys such as GOODS and zCOSMOS.


title:
Influence of the trap shape on the superfluid-Mott transition in
  ultracold atomic gases

abstract:
  The coexistence of superfluid and Mott insulator, due to the quadratic
confinement potential in current optical lattice experiments, makes the
accurate detection of the superfluid-Mott transition difficult. Studying
alternative trapping potentials which are experimentally realizable and have a
flatter center, we find that the transition can be better resolved, but at the
cost of a more difficult tuning of the particle filling. When mapping out the
phase diagram using local probes and the local density approximation we find
that the smoother gradient of the parabolic trap is advantageous.


title:
Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations:
  Cosmological Interpretation

abstract:
  (Abridged) The WMAP 5-year data strongly limit deviations from the minimal
LCDM model. We constrain the physics of inflation via Gaussianity,
adiabaticity, the power spectrum shape, gravitational waves, and spatial
curvature. We also constrain the properties of dark energy, parity-violation,
and neutrinos. We detect no convincing deviations from the minimal model. The
parameters of the LCDM model, derived from WMAP combined with the distance
measurements from the Type Ia supernovae (SN) and the Baryon Acoustic
Oscillations (BAO), are: Omega_b=0.0456+-0.0015, Omega_c=0.228+-0.013,
Omega_Lambda=0.726+-0.015, H_0=70.5+-1.3 km/s/Mpc, n_s=0.960+-0.013,
tau=0.084+-0.016, and sigma_8=0.812+-0.026. With WMAP+BAO+SN, we find the
tensor-to-scalar ratio r<0.22 (95% CL), and n_s>1 is disfavored regardless of
r. We obtain tight, simultaneous limits on the (constant) equation of state of
dark energy and curvature. We provide a set of "WMAP distance priors," to test
a variety of dark energy models. We test a time-dependent w with a present
value constrained as -0.33<1+w_0<0.21 (95% CL). Temperature and matter
fluctuations obey the adiabatic relation to within 8.9% and 2.1% for the axion
and curvaton-type dark matter, respectively. The TE and EB spectra constrain
cosmic parity-violation. We find the limit on the total mass of neutrinos,
sum(m_nu)<0.67 eV (95% CL), which is free from the uncertainty in the
normalization of the large-scale structure data. The effective number of
neutrino species is constrained as N_{eff} = 4.4+-1.5 (68%), consistent with
the standard value of 3.04. Finally, limits on primordial non-Gaussianity are
-9<f_{NL}^{local}<111 and -151<f_{NL}^{equil}<253 (95% CL) for the local and
equilateral models, respectively.


title:
z~7-10 Galaxies in the HUDF and GOODS fields, and their UV Luminosity
  Functions

abstract:
  We use all available deep optical ACS and near-IR data over both the HUDF and
the two GOODS fields to search for star-forming galaxies at z>~7 and constrain
the UV LF within the first 700 Myrs. Our data set includes ~23 arcmin^2 of deep
NICMOS J+H data and ~248 arcmin^2 of ground-based (ISAAC+MOIRCS) data,
coincident with ACS optical data of greater or equal depths. In total, we find
8 <z>~7.3 z-dropouts in our search fields, but no z~9 J-dropout candidates. A
careful consideration of a wide variety of different contaminants suggest an
overall contamination level of just ~12% for our z-dropout selection. After
performing detailed simulations to accurately estimate the selection volumes,
we derive constraints on the UV LFs at z~7 and z~9. For a faint-end slope
alpha=-1.74, our most likely values for M*(UV) and phi* at z~7 are -19.8+/-0.4
mag and 1.1_{-0.7}^{+1.7} x 10^{-3} Mpc^{-3}, respectively. Our search results
for z~9 J-dropouts set a 1 sigma lower limit on M*(UV) of -19.6 mag assuming
that phi* and alpha are the same as their values at slightly later times. This
lower limit on M*(UV) is 1.4 mag fainter than our best-fit value at z~4,
suggesting that the UV LF has undergone substantial evolution over this time
period. No evolution is ruled out at 99% confidence from z~7 to z~6 and at 80%
confidence from z~9 to z~7. The inferred brightening in M*(UV) with redshift
(i.e., M*(UV) = (-21.02+/-0.09) + (0.36+/-0.08)(z - 3.8)) matches the evolution
expected in the halo mass function, if the mass-to-light ratio of halos evolves
as ~(1+z)**{-1}. Finally, we consider the shape of the UV LF at z>~5 and
discuss the implications of the Schechter-like form of the observed LFs,
particularly the unexpected abrupt cut-off at the bright end.


title: A Transient Black-Hole Low-Mass X-Ray Binary Candidate in Centaurus A

abstract:
  We report the discovery of a bright transient X-ray source, CXOU
J132518.2-430304, towards Centaurus A (Cen A) using six new Chandra X-Ray
Observatory observations in 2007 March--May. Between 2003 and 2007, its flux
has increased by a factor of >770. The source is likely a low-mass X-ray binary
in Cen A with unabsorbed 0.3-10 keV band luminosities of (2-3) x 10^{39} erg
s^-1 and a transition from the steep-power law state to the thermal state
during our observations. CXOU J132518.2-430304 is the most luminous X-ray
source in an early-type galaxy with extensive timing information that reveals
transience and a spectral state transition. Combined with its luminosity, these
properties make this source one of the strongest candidates to date for
containing a stellar-mass black hole in an early-type galaxy. Unless this
outburst lasts many years, the rate of luminous transients in Cen A is
anomalously high compared to other early-type galaxies.


title: Sensitivity Parameter and Time Variations of Fundamental Constants

abstract:
  The sensitivity parameter is widely used for quantifying fine tuning.
However, examples show it fails to give correct results under certain
circumstances. We argue that the problems of the sensitivity parameter are
almost identical to the consequences we have to solved if the time-varying fine
structure constant is proved to be true. The high sensitivity of the energy
scale parameter (\Lambda) to the dimensionless coupling constant plays an
important role in these problems. It affects the reliability of the sensitivity
parameter via mechanisms such as dynamical symmetry breaking, chiral symmetry
breaking etc. The reliability of the sensitivity parameter can be improved if
it is used properly.


title: Old globular clusters in magellanic-type dwarf irregular galaxies

abstract:
  We present a study of the old globular clusters (GC) using archival F606W and
F814W HST/ACS images of 19 Magellanic-type dwarf Irregular (dIrr) galaxies
found in nearby (2 - 8 Mpc) associations of only dwarf galaxies. All dIrrs have
absolute magnitudes fainter than or equal to the SMC (Mv = -16.2 mag). We
detect 50 GC candidates in 13 dIrrs, of which 37 have (V-I) colors consistent
with "blue" (old, metal-poor) GCs (bGC). The luminosity function (LF) of the
bGCs in our sample peaks at Mv = -7.41 +/- 0.22 mag, consistent with other
galaxy types. The width of the LF is sigma = 1.79 +/- 0.31 which is typical for
dIrrs, but broader than the typical width in massive galaxies. The half-light
radii and ellipticities of the GCs in our sample (rh ~ 3.3 pc, e ~ 0.1) are
similar to those of old GCs in the Magellanic Clouds and to those of "Old Halo"
(OH) GCs in our Galaxy, but not as extended and spherical as the Galactic
"Young Halo" (YH) GCs (rh ~ 7.7 pc, e ~ 0.06). The e distribution shows a
turnover rather than a power law as observed for the Galactic GCs. This might
suggest that GCs in dIrrs are kinematically young and not fully relaxed yet.
The present-day specific frequencies (SN) span a broad range: 0.3 < SN < 11.
Assuming a dissipationless age fading of the galaxy light, the SN values would
increase by a factor of ~ 2.5 to 16, comparable with values for early-type
dwarfs (dE/dSphs). A bright central GC candidate, similar to nuclear clusters
of dEs, is observed in one of our dIrrs: NGC 1959. This nuclear GC has
luminosity, color, and structural parameters similar to that of wCen and M54,
suggesting that the latter might have their origin in the central regions of
similar Galactic building blocks. A comparison between properties of bGCs and
Galactic YH GCs, suspected to have originated from similar dIrrs, is performed.


title: Rough evolution equations

abstract:
  We generalize Lyons' rough paths theory in order to give a pathwise meaning
to some nonlinear infinite-dimensional evolution equation associated to an
analytic semigroup and driven by an irregular noise. As an illustration, we
discuss a class of linear and nonlinear 1d SPDEs driven by a space--time
Gaussian noise with singular space covariance and Brownian time dependence.


title: n-ary associative algebras, cohomology, free algebras and coalgebras

abstract:
  When $n$ is odd, a cohomology of type Hochschild for $n$-ary partially
associative algebras has been defined in Gnedbaye's thesis. Unfortunately, the
cohomology definition is not valid when $n$ is even. This fact is found again
in the computations of the $n$-ary partially associative free algebra.
  In this work, we define in a first time two approachs of an Hochschild
cohomology for $n$-ary partially associative algebras. First by reducing the
space of cochains, secondly by using a graded version. Next we compute the free
$n$-ary algebra, giving a basis of this algebra. At last we extend the notion
of coalgebras to $n$-ary algebras.


title: An upper limit on the electron-neutrino flux from the HiRes detector

abstract:
  Air-fluorescence detectors such as the High Resolution Fly's Eye (HiRes)
detector are very sensitive to upward-going, Earth-skimming ultrahigh energy
electron-neutrino-induced showers. This is due to the relatively large
interaction cross sections of these high-energy neutrinos and to the
Landau-Pomeranchuk-Migdal (LPM) effect. The LPM effect causes a significant
decrease in the cross sections for bremsstrahlung and pair production, allowing
charged-current electron-neutrino-induced showers occurring deep in the Earth's
crust to be detectable as they exit the Earth into the atmosphere. A search for
upward-going neutrino-induced showers in the HiRes-II monocular dataset has
yielded a null result. From an LPM calculation of the energy spectrum of
charged particles as a function of primary energy and depth for
electron-induced showers in rock, we calculate the shape of the resulting
profile of these showers in air. We describe a full detector Monte Carlo
simulation to determine the detector response to upward-going
electron-neutrino-induced cascades and present an upper limit on the flux of
electron-neutrinos.


title:
Discovery of a strong spiral magnetic field crossing the inner
  pseudoring of NGC 4736

abstract:
  We report the discovery of a coherent magnetic spiral structure within the
nearby ringed Sab galaxy NGC 4736. High sensitivity radio polarimetric data
obtained with the VLA at 8.46GHz and 4.86GHz show a distinct ring of total
radio emission precisely corresponding to the bright inner pseudoring visible
in other wavelengths. However, unlike the total radio emission, the polarized
radio emission reveals a clear pattern of ordered magnetic field of spiral
shape, emerging from the galactic centre. The magnetic vectors do not follow
the tightly-wrapped spiral arms that characterize the inner pseudoring, but
instead cross the ring with a constant and large pitch angle of about 35deg.
The ordered field is thus not local adjusted to the pattern of star-formation
activity, unlike what is usually observed in grand-design spirals. The observed
asymmetric distribution of Faraday rotation suggests the possible action of a
large-scale MHD dynamo. The strong magnetic total and regular field within the
ring (up to 30microG and 13microG, respectively) indicates that a highly
efficient process of magnetic field amplification is under way, probably
related to secular evolutionary processes in the galaxy.


title: Galactic Rotation Described with Thin-Disk Gravitational Model

abstract:
  The measured rotation velocity profiles of mature spiral galaxies are
successfully described with a gravitational model consisting of a thin
axisymmetric disk of finte radius. The disk is assumed uniformly thin but with
variable radial mass density. The governing integral equation is based on
mechanical balance between Newtonian gravitational and centrifugal forces (due
to galaxy rotation) at each and every point in a finite set of concentric
rings. The nondimensionalized mathematical system contains a dimensionless
parameter we call ``galactic rotation parameter'' which concisely crystallizes
perspective. Computational solutions are obtained for the radial mass
distributions that satisfy the measured rotational velocity profiles. Together
with a constraint equation for mass conservation, the galactic rotational
parameter is also determined from which the total galactic mass is calculated
from measured galactic radii and maximum rotation velocities. These calculated
total galactic masses are in good agreement with data. Our deduced
exponentially decreasing mass distributions in the central galactic core are in
agreement with almost all others. However our mass distributions differ toward
the galactic periphery with more ordinary baryonic mass in these outer disk
regions which are cooler with lower opactiy/emissivity (and thus darker).


title: Small Scale Behavior of Cosmic String Networks

abstract:
  The evolution of cosmic string networks is an interesting dynamical problem.
The equations governing these networks are classical and fully specified, but
the length scale at which cosmic string loops form has been uncertain to tens
of orders of magnitude. Numerical simulations are limited in the range of
length and time scales they can reach, while analytic methods have been limited
by the nonlinearities of the problem. We describe a recent analytic scaling
model developed in collaboration with Jorge Rocha and Florian Dubath which,
together with recent simulations, appears to resolve this question.


title: Energy-Enstrophy Stability of beta-plane Kolmogorov Flow with Drag

abstract:
  We develop a new nonlinear stability method, the Energy-Enstrophy (EZ)
method, that is specialized to two-dimensional hydrodynamics; the method is
applied to a beta-plane flow driven by a sinusoidal body force, and retarded by
drag with damping time-scale mu^{-1}. The standard energy method (Fukuta and
Murakami, J. Phys. Soc. Japan, 64, 1995, pp 3725) shows that the laminar
solution is monotonically and globally stable in a certain portion of the
(mu,beta)-parameter space. The EZ method proves nonlinear stability in a larger
portion of the (mu,beta)-parameter space. And by penalizing high wavenumbers,
the EZ method identifies a most strongly amplifying disturbance that is more
physically realistic than that delivered by the energy method. Linear
instability calculations are used to determine the region of the
(mu,beta)-parameter space where the flow is unstable to infinitesimal
perturbations. There is only a small gap between the linearly unstable region
and the nonlinearly stable region, and full numerical solutions show only small
transient amplification in that gap.

categories: physics.flu-dyn nlin.CD physics.ao-ph physics.geo-ph


title: Simulation of an inhomogeneous Fermi gas through the BCS-BEC crossover

abstract:
  We perform a variational quantum Monte Carlo simulation of the transition
from a Bardeen-Cooper-Schrieffer superfluid (BCS) to a Bose-Einstein condensate
(BEC) at zero temperature. The model Hamiltonian involves an attractive short
range two body interaction and the atoms number $2N =330$ is chosen so that, in
the non-interacting limit, the ground state function corresponds to a closed
shell configuration. The system is then characterized by the s-wave scattering
length $a$ of the two-particle collisions in the gas, which is varied from
negative to positive values, and the Fermi wave number $k_F$. Based on an
extensive analysis of the s-wave two-body problem, one parameter variational
many-body wave functions are proposed to describe the ground state of the
interacting Fermi gas from BCS to BEC states. We exploit properties of
antisymmetrized many-body functions to develop efficient techniques that permit
variational calculations for a large number of particles. It is shown that a
virial relation between the energy per particle and the trapping energy is
approximately valid for $-0.1<1/k_Fa<3.4$. The influence of the harmonic trap
and the interaction potential as exhibited in two-body correlation functions is
also analyzed.


title:
Neutral and charged excitations in carbon fullerenes from
  first-principles many-body theories

abstract:
  We investigate the accuracy of first-principles many-body theories at the
nanoscale by comparing the low energy excitations of the carbon fullerenes
C_20, C_24, C_50, C_60, C_70, and C_80 with experiment. Properties are
calculated via the GW-Bethe-Salpeter Equation (GW-BSE) and diffusion Quantum
Monte Carlo (QMC) methods. We critically compare these theories and assess
their accuracy against available photoabsorption and photoelectron spectroscopy
data. The first ionization potentials are consistently well reproduced and are
similar for all the fullerenes and methods studied. The electron affinities and
first triplet excitation energies show substantial method and geometry
dependence. These results establish the validity of many-body theories as
viable alternative to density-functional theory in describing electronic
properties of confined carbon nanostructures. We find a correlation between
energy gap and stability of fullerenes. We also find that the electron affinity
of fullerenes is very high and size-independent, which explains their tendency
to form compounds with electron-donor cations.


title: A Multiplicity Census of Young Stars in Chamaeleon I

abstract:
  We present the results of a multiplicity survey of 126 stars spanning ~0.1-3
solar masses in the ~2-Myr-old Chamaeleon I star-forming region, based on
adaptive optics imaging with the ESO Very Large Telescope. Our observations
have revealed 30 binaries and 6 triples, of which 19 and 4, respectively, are
new discoveries. The overall multiplicity fraction we find for Cha I (~30%) is
similar to those reported for other dispersed young associations, but
significantly higher than seen in denser clusters and the field, for comparable
samples. Both the frequency and the maximum separation of Cha I binaries
decline with decreasing mass, while the mass ratios approach unity; conversely,
tighter pairs are more likely to be equal mass. We confirm that brown dwarf
companions to stars are rare, even at young ages at wide separations. Based on
follow-up spectroscopy of two low-mass substellar companion candidates, we
conclude that both are likely background stars. The overall multiplicity
fraction in Cha I is in rough agreement with numerical simulations of cloud
collapse and fragmentation, but its observed mass dependence is less steep than
predicted. The paucity of higher-order multiples, in particular, provides a
stringent constraint on the simulations, and seems to indicate a low level of
turbulence in the prestellar cores in Cha I.


title: Topological wave functions and the 4D-5D lift

abstract:
  We revisit the holomorphic anomaly equations satisfied by the topological
string amplitude from the perspective of the 4D-5D lift, in the context of
''magic'' N=2 supergravity theories. In particular, we interpret the
Gopakumar-Vafa relation between 5D black hole degeneracies and the topological
string amplitude as the result of a canonical transformation from 4D to 5D
charges. Moreover we use the known Bekenstein-Hawking entropy of 5D black holes
to constrain the asymptotic behavior of the topological wave function at finite
topological coupling but large K\"ahler classes. In the process, some
subtleties in the relation between 5D black hole degeneracies and the
topological string amplitude are uncovered, but not resolved. Finally we extend
these considerations to the putative one-parameter generalization of the
topological string amplitude, and identify the canonical transformation as a
Weyl reflection inside the 3D duality group.


title:
Highly conductive molecular junctions based on direct binding of benzene
  to platinum electrodes

abstract:
  Highly conductive molecular junctions were formed by direct binding of
benzene molecules between two Pt electrodes. Measurements of conductance,
isotopic shift in inelastic spectroscopy and shot noise compared with
calculations provide indications for a stable molecular junction where the
benzene molecule is preserved intact and bonded to the Pt leads via carbon
atoms. The junction has a conductance comparable to that for metallic atomic
junctions (around 0.1-1 Go), where the conductance and the number of
transmission channels are controlled by the molecule's orientation at different
inter-electrode distances.


title: Non-Markovian qubit dynamics in the presence of 1/f noise

abstract:
  Within the lowest-order Born approximation, we calculate the exact dynamics
of a single qubit in the presence of 1/f noise, without making any Markov
approximation. We show that the non-Markovian qubit time-evolution exhibits
asymmetries and beatings that cannot be explained within a Markovian theory.
The present theory for 1/f noise is relevant for both spin- and superconducting
qubit realizations in solid-state devices, where 1/f noise is ubiquitous.


title:
Astronomical spectrograph calibration with broad-spectrum frequency
  combs

abstract:
  Broadband femtosecond-laser frequency combs are filtered to
spectrographically resolvable frequency-mode spacing, and the limitations of
using cavities for spectral filtering are considered. Data and theory are used
to show implications to spectrographic calibration of high-resolution,
astronomical spectrometers.


title:
Inverse eigenvalue problems for Sturm-Liouville equations with spectral
  parameter linearly contained in one of the boundary conditions

abstract:
  Inverse problems of recovering the coefficients of Sturm-Liouville problems
with the eigenvalue parameter linearly contained in one of the boundary
conditions are studied: (1) from the sequences of eigenvalues and norming
constants; (2) from two spectra. Necessary and sufficient conditions for the
solvability of these inverse problems are obtained.


title: The isotope effect in the Hubbard model with local phonons

abstract:
  The isotope effect (IE) in the two-dimensional Hubbard model with Holstein
phonons is studied using the dynamical cluster approximation with quantum Monte
Carlo. At small electron-phonon (EP) coupling the IE is negligible. For larger
EP coupling there is a large and positive IE on the superconducting temperature
that decreases with increasing doping. A significant IE also appears in the
low-energy density of states, kinetic energy and charge excitation spectrum. A
negligible IE is found in the pseudogap and antiferromagnetic (AF) properties
at small doping whereas the AF susceptibility at intermediate doping increases
with decreasing phonon frequency $\omega_0$. This IE stems from increased
polaronic effects with decreasing $\omega_0$. A larger IE at smaller doping
occurs due to stronger polaronic effects determined by the interplay of the EP
interaction with stronger AF correlations. The IE of the Hubbard-Holstein model
exhibits many similarities with the IE measured in cuprate superconductors.


title:
Measurement of Aharonov-Bohm oscillations in mesoscopic metallic rings
  in the presence of high-frequency electromagnetic fields

abstract:
  We report measurements of Aharonov-Bohm oscillations in normal metal rings in
the presence of high frequency electromagnetic fields. The power dependence of
the decoherence time scale tau_phi(P) agrees well with the anticipated power
law tau_phi proportional to P^(-1/5) when the field-induced decoherence rate
tau_ac^(-1) is large compared to the intrinsic decoherence rate tau_o^(-1),
measured in the absence of external fields. As theoretically expected, we
observe a decline in field-induced decoherence when tau_ac^(-1)<=tau_o^(-1).
The frequency dependence of tau_phi shows a minimum in the oscillation
amplitude at a characteristic frequency, omega_(ac)=1/tau_(o), where tau_(o) is
evaluated from the oscillation amplitude using the standard mesoscopic theory.
Both the suppression in the oscillation amplitude and the concomitant change in
conductivity allow a direct measurement of the intrinsic decoherence time
scale.


title: Electrical control of a laterally ordered InAs/InP quantum dash array

abstract:
  We have fabricated an array of closely spaced quantum dashes starting from a
planar array of self-assembled semiconductor quantum wires. The array is
embedded in a metallic nanogap which we investigate by micro-photoluminescence
as a function of a lateral electric field. We demonstrate that the net electric
charge and emission energy of individual quantum dashes can be modified
externally with performance limited by the size inhomogeneity of the
self-assembling process.


title:
Five-Year Wilkinson Microwave Anisotropy Probe (WMAP)Observations: Beam
  Maps and Window Functions

abstract:
  Cosmology and other scientific results from the WMAP mission require an
accurate knowledge of the beam patterns in flight. While the degree of beam
knowledge for the WMAP one-year and three-year results was unprecedented for a
CMB experiment, we have significantly improved the beam determination as part
of the five-year data release. Physical optics fits are done on both the A and
the B sides for the first time. The cutoff scale of the fitted distortions on
the primary mirror is reduced by a factor of ~2 from previous analyses. These
changes enable an improvement in the hybridization of Jupiter data with beam
models, which is optimized with respect to error in the main beam solid angle.
An increase in main-beam solid angle of ~1% is found for the V2 and W1-W4
differencing assemblies. Although the five-year results are statistically
consistent with previous ones, the errors in the five-year beam transfer
functions are reduced by a factor of ~2 as compared to the three-year analysis.
We present radiometry of the planet Jupiter as a test of the beam consistency
and as a calibration standard; for an individual differencing assembly, errors
in the measured disk temperature are ~0.5%.


title: Polyakov formulas for GJMS operators from AdS/CFT

abstract:
  We argue that the AdS/CFT calculational prescription for double-trace
deformations leads to a holographic derivation of the conformal anomaly, and
its conformal primitive, associated to the whole family of conformally
covariant powers of the Laplacian (GJMS operators) at the conformal boundary.
The bulk side involves a quantum 1-loop correction to the SUGRA action and the
boundary counterpart accounts for a sub-leading term in the large-N limit. The
sequence of GJMS conformal Laplacians shows up in the two-point function of the
CFT operator dual to a bulk scalar field at certain values of its scaling
dimension. The restriction to conformally flat boundary metrics reduces the
bulk computation to that of volume renormalization which renders the universal
type A anomaly. In this way, we directly connect two chief roles of the
Q-curvature: the main term in Polyakov formulas on one hand, and its relation
to the Poincare metrics of the Fefferman-Graham construction, on the other
hand. We find agreement with previously conjectured patterns including a
generic and simple formula for the type A anomaly coefficient that matches all
reported values in the literature concerning GJMS operators, to our knowledge.


title: Almost-rainbow edge-colorings of some small subgraphs

abstract:
  Let $f(n,p,q)$ be the minimum number of colors necessary to color the edges
of $K_n$ so that every $K_p$ is at least $q$-colored. We improve current bounds
on the {7/4}n-3$, slightly improving the bound of Axenovich. We make small
improvements on bounds of Erd\H os and Gy\'arf\'as by showing ${5/6}n+1\leq
f(n,4,5)$ and for all even $n\not\equiv 1 \pmod 3$, $f(n,4,5)\leq n-1$ . For a
complete bipartite graph $G=K_{n,n}$, we show an n-color construction to color
the edges of $G$ so that every $C_4\subseteq G$ is colored by at least three
colors. This improves the best known upper bound of M. Axenovich, Z. F\"uredi,
and D. Mubayi.


title: The implicitization problem for $\phi: P^n --> (P^1)^{n+1}$

abstract:
  We develop in this paper some methods for studying the implicitization
problem for a rational map $\phi: \mathbb{P}^n \to (\mathbb{P}^1)^{n+1}$
defining a hypersurface in $(\mathbb{P}^1)^{n+1}$, based on computing the
determinant of a graded strand of a Koszul complex. We show that the classical
study of Macaulay Resultants and Koszul complexes coincides, in this case, with
the approach of approximation complexes and we study and give a geometric
interpretation for the acyclicity conditions. Under suitable hypotheses, these
techniques enable us to obtain the implicit equation, up to a power, and up to
some other extra factor. We give algebraic and geometric conditions for
determining when the computed equation defines the scheme theoretic image of
$\phi$, and, what are the extra varieties that appear. We also give some
applications to the problem of computing sparse discriminants.


title: New agegraphic dark energy model with generalized uncertainty principle

abstract:
  We investigate the new agegraphic dark energy models with generalized
uncertainty principle (GUP). It turns out that although the GUP affects the
early universe, it does not change the current and future dark energy-dominated
universe significantly. Furthermore, this model could describe the
matter-dominated universe in the past only when the parameter $n$ is chosen to
be $n>n_c$, where the critical value determined to be $n_c=2.799531478$.


title: Projections of a learning space

abstract:
  Any subset Q' of the domain Q of a learning space defines a projection of
that learning space on Q' which is itself a learning space consistent with the
original one. Moreover, such a construction defines a partition of Q having
each of its classes defining a learning space also consistent with the original
learning space. We give a direct proof of these facts which are instrumental in
parsing large learning spaces.


title:
The Secular Evolution of a Close Ring-Satellite System: The Excitation
  of Spiral Density Waves at a Nearby Gap Edge

abstract:
  The Lagrange planetary equations are used to study to secular evolution of a
small, eccentric satellite that orbits within a narrow gap in a broad,
self-gravitating planetary ring. These equations show that the satellite's
secular perturbations of the ring will excite a very long-wavelength spiral
density wave that propagates away from the gap's outer edge. The amplitude of
these waves, as well as their dispersion relation, are derived here. That
dispersion relation reveals that a planetary ring can sustain two types of
density waves: long waves that, in Saturn's A ring, would have wavelengths of
order 100 km, and short waves that tend to be very nonlinear and are expected
to quickly damp. The excitation of these waves also transports angular momentum
from the ring to the satellite in a way that damps the satellite's eccentricity
e, which also tends to reduce the amplitude of subsequent waves. The rate of
eccentricity damping due to this wave action is then compared to the rates at
which the satellite's Lindblad and corotation resonances alter the satellite's
e. These results are then applied to the gap-embedded Saturnian satellites Pan
and Daphnis, and the long-term stability of their eccentricities is assessed.


title: The Wilkinson Microwave Anisotropy Probe (WMAP) Source Catalog

abstract:
  We present the list of point sources found in the WMAP 5-year maps. The
technique used in the first-year and three-year analysis now finds 390 point
sources, and the five-year source catalog is complete for regions of the sky
away from the galactic plane to a 2 Jy limit, with SNR > 4.7 in all bands in
the least covered parts of the sky. The noise at high frequencies is still
mainly radiometer noise, but at low frequencies the CMB anisotropy is the
largest uncertainty. A separate search of CMB-free V-W maps finds 99 sources of
which all but one can be identified with known radio sources. The sources seen
by WMAP are not strongly polarized. Many of the WMAP sources show significant
variability from year to year, with more than a 2:1 range between the minimum
and maximum fluxes.


title: On mirabolic D-modules

abstract:
  Let an algebraic group G act on X, a connected algebraic manifold, with
finitely many orbits. For any Harish-Chandra pair (D,G) where D is a sheaf of
twisted differential operators on X, we form a left ideal D.g in D generated by
the Lie algebra g, of G. Then, D/D.g is a holonomic D-module and its
restriction to a unique Zariski open dense G-orbit in X is a G-equivariant
local system. We prove a criterion saying that the D-module D/D.g is
isomorphic, under certain (quite restrictive) conditions, to a direct image of
that local system to X. We apply this criterion in the special case where the
group G=SL(n) acts diagonally on X = F \times F \times P^{n-1}, a triple
product where F is the flag manifold for SL(n) and P^{n-1} is the projective
space.
  We further relate D-modules on F \times F \times P^{n-1} to D-modules on the
space SL(n) \times P^{n-1} via a pair, CH, HC, of adjoint functors, analogous
to those used in Lusztig's theory of character sheaves.
  A second important result of the paper provides an explicit description of
these functors showing that the functor HC gives an exact functor on the
abelian category of mirabolic D-modules.


title: Equivalence between Bell inequalities and quantum Minority game

abstract:
  We show that, for a continuous set of entangled four-partite states, the task
of maximizing the payoff in the symmetric-strategy four-player quantum Minority
game is equivalent to maximizing the violation of a four-particle Bell
inequality with each observer choosing the same set of two dichotomic
observables. We conclude the existence of direct correspondences between (i)
the payoff rule and Bell inequalities, and (ii) the strategy and the choice of
measured observables in evaluating these Bell inequalities. We also show that
such a correspondence between Bell polynomials (in a single plane) and
four-player, symmetric, binary-choice quantum games is unique to the
four-player quantum Minority game and its "anti-Minority" version. This
indicates that the four-player Minority game not only plays a special role
among quantum games but also in studies of Bell-type quantum nonlocality.


title:
Extracting the spectral function of the cuprates by a full
  two-dimensional analysis: Angle-resolved photoemission spectra of Bi2Sr2CuO6

abstract:
  Recently, angle-resolved photoemission spectroscopy (ARPES) has revealed a
dispersion anomaly at high binding energy near 0.3-0.5eV in various families of
the high-temperature superconductors. For further studies of this anomaly we
present a new two-dimensional fitting-scheme and apply it to high-statistics
ARPES data of the strongly-overdoped Bi2Sr2CuO6 cuprate superconductor. The
procedure allows us to extract theself-energy in an extended energy and
momentum range. It is found that the spectral function of Bi2Sr2CuO6 can be
parameterized using a small set of tight-binding parameters and a
weakly-momentum-dependent self-energy up to 0.7 eV in binding energy and over
the entire first Brillouin zone. Moreover the analysis gives an estimate of the
momentum dependence of the matrix element, a quantity, which is often neglected
in ARPES analyses.


title: Quark Potential in a Quark-Meson Plasma

abstract:
  We investigate quark potential by considering meson exchanges in the two
flavor Nambu--Jona-Lasinio model at finite temperature and density. There are
two kinds of oscillations in the chiral restoration phase, one is the Friedel
oscillation due to the sharp quark Fermi surface at high density, and the other
is the Yukawa oscillation driven by the complex meson poles at high
temperature. The quark-meson plasma is strongly coupled in the temperature
region $1\le T/T_c \lesssim 3$ with $T_c$ being the critical temperature of
chiral phase transition. The maximum coupling in this region is located at the
critical point.


title:
Amine-Linked Single Molecule Circuits: Systematic Trends Across
  Molecular Families

abstract:
  A comprehensive review is presented of single molecule junction conductance
measurements across families of molecules measured while breaking a gold point
contact in a solution of molecules with amine end groups. A theoretical
framework unifies the picture for the amine-gold link bonding and the tunnel
coupling through the junction using Density Functional Theory based
calculations. The reproducible electrical characteristics and utility for many
molecules is shown to result from the selective binding between the gold
electrodes and amine link groups through a donor-acceptor bond to
undercoordinated gold atoms. While the bond energy is modest, the maximum force
sustained by the junction is comparable to, but less than, that required to
break gold point contacts. The calculated tunnel coupling provides conductance
trends for all 41 molecule measurements presented here, as well as insight into
the variability of conductance due to the conformational changes within
molecules with torsional degrees of freedom. The calculated trends agree to
within a factor of two of the measured values for conductance ranging from 10-7
G0 to 10-2 G0, where G0 is the quantum of conductance (2e2/h).


title: Searching for zeroes: unconventional superconductors in a magnetic field

abstract:
  We review the results of the microscopic approach to the calculation of the
anisotropy in the specific heat in unconventional superconductors under rotated
field. Treating vortex scattering on equal footing with the energy shift we
find that the electronic specific heat may have minima or maxima when the field
is aligned with the nodes, depending on the temperature and field range. We
discuss the influence of the paramagnetic limiting and Fermi surface shape on
the location of the inversion line.


title:
Angular Momentum Transport in Accretion Disks and its Implications for
  Spin Estimates in Black Hole Binaries

abstract:
  The accretion flow in the disk dominated state of black hole binaries has
peak temperature and luminosity which vary together in such a way as to
indicate an approximately constant emitting area. The association of this with
the last stable orbit gives one of the few ways to estimate spin when the mass
of the black hole is known. However, deriving this radius requires knowledge of
how the disk spectrum is modified by radiative transfer through the vertical
structure of the disk, as well as special and general relativistic effects on
the propagation of this radiation. Here we investigate the extent to which
differences in vertical structure change the derived disk spectra by
calculating these for a range of different stress prescriptions. We find that
at a given mass accretion rate the spectra are almost identical for accretion
rates of L/L_Edd <~ 0.1. The spectra are remarkably similar even up to the
highest luminosities considered (L/L_Edd ~ 0.6) as long as the stresses do not
dissipate more than about 10 per cent of the gravitational energy above the
effective photosphere. This is exceeded only by classic alpha disks with alpha
>~ 0.1, but these models give spectral variation which is incompatible with
existing data. Therefore, we conclude that disk spectral modelling can place
interesting constraints on angular momentum transport, but still provide a
robust estimate of the spin of the black hole.


title: Deriving local order parameters from tensor network representations

abstract:
  A large class of quantum phase transitions for quantum lattice systems are
characterized by local order parameters. It is shown that local order
parameters may be systematically constructed from tensor network
representations of quantum many-body ground state wave functions by
investigating the reduced density matrices for local areas on an infinite-size
lattice. Depending on whether or not the system symmetries are spontaneously
broken, and whether or not the ground state fidelity per lattice site is
continuous, there are four categories of quantum phase transitions for systems
with local order parameters. Quantum phase transitions characterized by
nonlocal order parameters are discussed, aiming at better understanding quantum
systems with topological order.


title:
Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations:
  Likelihoods and Parameters from the WMAP data

abstract:
  This paper focuses on cosmological constraints derived from analysis of WMAP
data alone. A simple LCDM cosmological model fits the five-year WMAP
temperature and polarization data. The basic parameters of the model are
consistent with the three-year data and now better constrained: Omega_b h^2 =
0.02273+-0.00062, Omega_c h^2 = 0.1099+-0.0062, Omega_L = 0.742+-0.030, n_s =
0.963+0.014- 0.015, tau = 0.087+-0.017, sigma_8 = 0.796+-0.036. With five years
of polarization data, we have measured the optical depth to reionization,
tau>0, at 5 sigma significance. The redshift of an instantaneous reionization
is constrained to be z_reion = 11.0+-1.4 with 68% confidence. This excludes a
sudden reionization of the universe at z=6 at more than 3.5 sigma significance,
suggesting that reionization was an extended process. Using two methods for
polarized foreground cleaning we get consistent estimates for the optical
depth, indicating an error due to foreground treatment of tau~0.01. This
cosmological model also fits small-scale CMB data, and a range of astronomical
data measuring the expansion rate and clustering of matter in the universe. We
find evidence for the first time in the CMB power spectrum for a non-zero
cosmic neutrino background, or a background of relativistic species, with the
standard three light neutrino species preferred over the best-fit LCDM model
with N_eff=0 at >99.5% confidence, and N_eff > 2.3 (95% CL) when varied. The
five-year WMAP data improve the upper limit on the tensor-to-scalar ratio to r
< 0.43 (95% CL), for power-law models. With longer integration we find no
evidence for a running spectral index, with dn_s/dlnk = -0.037+-0.028.


title:
Subarcsecond Submillimeter Imaging of the Ultracompact HII Region
  G5.89-0.39

abstract:
  We present the first subarcsecond submillimeter images of the enigmatic
ultracompact HII region (UCHII) G5.89-0.39. Observed with the SMA, the 875
micron continuum emission exhibits a shell-like morphology similar to longer
wavelengths. By using images with comparable angular resolution at five
frequencies obtained from the VLA archive and CARMA, we have removed the
free-free component from the 875 micron image. We find five sources of dust
emission: two compact warm objects (SMA1 and SMA2) along the periphery of the
shell, and three additional regions further out. There is no dust emission
inside the shell, supporting the picture of a dust-free cavity surrounded by
high density gas. At subarcsecond resolution, most of the molecular gas tracers
encircle the UCHII region and appear to constrain its expansion. We also find
G5.89-0.39 to be almost completely lacking in organic molecular line emission.
The dust cores SMA1 and SMA2 exhibit compact spatial peaks in optically-thin
gas tracers (e.g. 34SO2), while SMA1 also coincides with 11.9 micron emission.
In CO(3-2), we find a high-velocity north/south bipolar outflow centered on
SMA1, aligned with infrared H2 knots, and responsible for much of the maser
activity. We conclude that SMA1 is an embedded intermediate mass protostar with
an estimated luminosity of 3000 Lsun and a circumstellar mass of ~1 Msun.
Finally, we have discovered an NH3 (3,3) maser 12 arcsec northwest of the UCHII
region, coincident with a 44 GHz CH3OH maser, and possibly associated with the
Br gamma outflow source identified by Puga et al. (2006).


title:
Homotopy theory of the master equation package applied to algebra and
  geometry: a sketch of two interlocking programs

abstract:
  We interpret mathematically the pair (master equation, solution of master
equation) up to equivalence, as the pair (a presentation of a free triangular
dga T over a combination operad O, dga map of T into C, a dga over O) up to
homotopy equivalence of dgOa maps, see Definition 1. We sketch two general
applications: I to the theory of the definition and homotopy theory of infinity
versions of general algebraic structures including noncompact frobenius
algebras and Lie bialgebras. Here the target C would be the total Hom complex
between various tensor products of another chain complex B, C = HomB, O
describes combinations of operations like composition and tensor product
sufficient to describe the algebraic structure and one says that B has the
algebraic structure in question. II to geometric systems of moduli spaces up to
deformation like the moduli of J holomorphic curves. Here C is some geometric
chain complex containing the fundamental classes of the moduli spaces of the
geometric problem. We also discuss analogues of homotopy groups and Postnikov
systems for maps and impediments to using them related to linear terms in the
master equation called anomalies.


title:
A non-Archimedean analogue of the Hodge-D-conjecture for products of
  elliptic curves

abstract:
  In this paper we show that the map % $$\partial:CH^2(E_1 \times E_2,1)\otimes
\Q \longrightarrow PCH^1(\XX_v)$$ % is surjective, where $E_1$ and $E_2$ are
two non-isogenous semistable elliptic curves over a local field, $CH^2(E_1
\times E_2,1)$ is one of Bloch's higher Chow groups and $PCH^1(\XX_v)$ is a
certain subquotient of a Chow group of the special fibre $\XX_{v}$ of a
semi-stable model $\XX$ of $E_1 \times E_2$. On one hand, this can be viewed as
a non-Archimedean analogue of the Hodge-$\D$-conjecture of Beilinson - which is
known to be true in this case by the work of Chen and Lewis \cite{lech}, and on
the other, an analogue of the works of Spei{\ss} \cite{spie}, Mildenhall
\cite{mild} and Flach \cite{flac} in the case when the elliptic curves have
split multiplicative reduction.


title:
Systematic study of $^{9,10,11}$Li with the tensor and pairing
  correlations

abstract:
  We make a systematic study of Li isotopes (A=9,10,11) in the tensor optimized
shell model for 9Li and treat the additional valence neutrons in the cluster
model approach by taking into account the Pauli-blocking effect caused by the
tensor and pairing correlations. We describe the tensor correlations in 9Li
fully in the tensor-optimized shell model, where the variation of the size
parameters of the single particle orbits is essential for getting strong tensor
correlations. We have shown in our previous study that in $^{10,11}$Li the
tensor and pairing correlations in 9Li are Pauli-blocked by additional valence
neutrons, which make the p-shell configurations pushed up in energy. As a
result, the $s^2$ valence neutron component increases to reveal the halo
structure of 11Li and the inversion phenomenon of the single particle spectrum
in 10Li arises. Following the previous study, we demonstrate the reliability of
our framework by performing a detailed systematic analysis of the structures of
$^{9,10,11}$Li, such as the charge radius, the spatial correlation of halo
neutrons of 11Li and the electromagnetic properties of Li isotopes. The
detailed effects of the Pauli-blocking on the spectroscopic properties of
$^{10,11}$Li are also discussed. It is found that the blocking acts strongly
for the 11Li ground state rather than for 10Li and for the dipole excited
states of 11Li, which is mainly caused by the interplay between the tensor
correlation in 9Li and the halo neutrons. The results obtained in these
analyses clearly show that the inert core assumption of 9Li is not realistic to
explain the anomalous structures observed in $^{10,11}$Li. For the dipole
excitation spectrum of 11Li, the effect of the final state interactions is
discussed in terms of the dipole strength function.


title:
Relative entropy for maximal abelian subalgebras of matrices and the
  entropy of unistochastic matrices

abstract:
  Let $A$ and $B$ be two maximal abelian *-subalgebras of the $n\times n$
complex matrices $M_n(\mathbb{C}).$ To study the movement of the inner
automorphisms of $M_n(\mathbb{C}),$ we modify the Connes-St$\o$rmer relative
entropy $H(A | B)$ and the Connes relative entropy $H_\phi(A | B)$ with respect
to a state $\phi,$ and introduce the two kinds of the constant $h(A | B)$ and
$h_\phi(A | B).$ For the unistochastic matrix $b(u)$ defined by a unitary $u$
with $B = uAu^*,$ we show that $h(A | B)$ is the entropy $H(b(u))$ of $b(u).$
This is obtained by our computation of $h_\phi(A | B).$ The $h(A | B)$ attains
to the maximal value $\log n$ if and only if the pair $\{A, B\}$ is orthogonal
in the sense of Popa.


title: 2D binary operadic Lax representation for harmonic oscillator

abstract:
  It is explained how the time evolution of operadic variables may be
introduced by using the operadic Lax equation. As an example, a 2-dimensional
binary operadic Lax representation for the harmonic oscillator is constructed.


title:
Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations:
  Angular Power Spectra

abstract:
  We present the temperature and polarization angular power spectra of the
cosmic microwave background (CMB) derived from the first 5 years of WMAP data.
The 5-year temperature (TT) spectrum is cosmic variance limited up to multipole
l=530, and individual l-modes have S/N>1 for l<920. The best fitting
six-parameter LambdaCDM model has a reduced chi^2 for l=33-1000 of
chi^2/nu=1.06, with a probability to exceed of 9.3%. There is now significantly
improved data near the third peak which leads to improved cosmological
constraints. The temperature-polarization correlation (TE) is seen with high
significance. After accounting for foreground emission, the low-l reionization
feature in the EE power spectrum is preferred by \Delta\chi^2=19.6 for optical
depth tau=0.089 by the EE data alone, and is now largely cosmic variance
limited for l=2-6. There is no evidence for cosmic signal in the BB, TB, or EB
spectra after accounting for foreground emission. We find that, when averaged
over l=2-6, l(l+1)C^{BB}_l/2\pi < 0.15 uK^2 (95% CL).


title: Cross-talk suppressed multi-anode MCP-PMT

abstract:
  We have developed a 4-channel multi-anode MCP-PMT, SL10, which exhibits a
performance of sigma_TTS ~ 30 ps for single photons with G ~ 10^6 and QE=20%
under a magnetic field of B <= 1.5 T. The cross-talk among anodes has been
extensively studied. We have taken two measures to suppress it: one is to
configure the SL10 to an effectively independent 4 small pieces of MCP-PMT's by
segmenting an electrode of the second MCP-layer; the other is to use a constant
fractional discriminator. Remarkable improvement has been achieved.


title:
The Relationship Between a Function, a Functions Inverse, and their
  Antiderivatives with an Emphasis in Finding Exact Roots with the Technique of
  Integration

abstract:
  Using a new technique involving integration it is possible to find the exact
roots of simple functions. In this case, simple functions are defined as smooth
functions having an inverse, and that inverse having an antiderivative. This
technique now makes it possible to find the exact roots of certain functions
without the use of numerical or iterative methods.


title: Quantum group structure of the q-deformed $W$ algebra $\WW_q$

abstract:
  In this paper the q-deformed $W$ algebra $\WW_q$ is constructed, whose
nontrivial quantum group structure is presented.


title: Cooperative Spectrum Sensing Using Random Matrix Theory

abstract:
  In this paper, using tools from asymptotic random matrix theory, a new
cooperative scheme for frequency band sensing is introduced for both AWGN and
fading channels. Unlike previous works in the field, the new scheme does not
require the knowledge of the noise statistics or its variance and is related to
the behavior of the largest and smallest eigenvalue of random matrices.
Remarkably, simulations show that the asymptotic claims hold even for a small
number of observations (which makes it convenient for time-varying topologies),
outperforming classical energy detection techniques.


title:
Galaxy Clusters in the Line of Sight to Background Quasars: I. Survey
  Design and Incidence of MgII Absorbers at Cluster Redshifts

abstract:
  We describe the first optical survey of absorption systems associated with
galaxy clusters at z= 0.3-0.9. We have cross-correlated SDSS DR3 quasars with
high-redshift cluster/group candidates from the Red-Sequence Cluster Survey. We
have found 442 quasar-cluster pairs for which the MgII doublet might be
detected at a transverse (physical) distance d<2 Mpc from the cluster centers.
To investigate the incidence (dN/dz) and equivalent-width distribution n(W) of
MgII systems at cluster redshifts, two statistical samples were drawn out of
these pairs: one made of high-resolution spectroscopic quasar observations (46
pairs), and one made of quasars used in MgII searches found in the literature
(375 pairs). The results are: (1) the population of strong MgII systems
(W_0>2.0 Ang.) near cluster redshifts shows a significant (>3 sigma)
overabundance (up to a factor of 15) when compared with the 'field' population;
(2) the overabundance is more evident at smaller distances (d<1 Mpc) than
larger distances (d<2 Mpc) from the cluster center; and, (3) the population of
weak MgII systems (W_0<0.3 Ang.) near cluster redshifts conform to the field
statistics. Unlike in the field, this dichotomy makes n(W) in clusters appear
flat and well fitted by a power-law in the entire W-range. A sub-sample of the
most massive clusters yields a stronger and still significant signal. Since
either the absorber number density or filling-factor/cross-section affects the
absorber statistics, an interesting possibility is that we have detected the
signature of truncated halos due to environmental effects. Thus, we argue that
the excess of strong systems is due to a population of absorbers in an
overdense galaxy environment, and the lack of weak systems to a different
population, that got destroyed in the cluster environment. (Abridged)


title: Innovative Weak Formulation for The Landau-Lifshitz-Gilbert Equations

abstract:
  A non-conventional finite element formalism is proposed to solve the dynamic
Landau-Lifshitz-Gilbert micromagnetic equations. Two bidimensional test
problems are treated to estimate the validity and the accuracy of this finite
element approach


title: Superposition rules and stochastic Lie-Scheffers systems

abstract:
  This paper proves a version for stochastic differential equations of the
Lie-Scheffers Theorem. This result characterizes the existence of nonlinear
superposition rules for the general solution of those equations in terms of the
involution properties of the distribution generated by the vector fields that
define it. When stated in the particular case of standard deterministic
systems, our main theorem improves various aspects of the classical
Lie-Scheffers result. We show that the stochastic analog of the classical
Lie-Scheffers systems can be reduced to the study of Lie group valued
stochastic Lie-Scheffers systems; those systems, as well as those taking values
in homogeneous spaces are studied in detail. The developments of the paper are
illustrated with several examples.


title:
Gerasimov-Drell-Hearn Sum Rule and the Discrepancy between the New CLAS
  and SAPHIR Data

abstract:
  Contribution of the K^+\Lambda channel to the Gerasimov-Drell-Hearn (GDH) sum
rule has been calculated by using the models that fit the recent SAPHIR or CLAS
differential cross section data. It is shown that the two data sets yield quite
different contributions. Contribution of this channel to the forward spin
polarizability of the proton has been also calculated. It is also shown that
the inclusion of the recent CLAS C_x and C_z data in the fitting data base does
not significantly change the result of the present calculation. Results of the
fit, however, reveal the role of the S_{11}(1650), P_{11}(1710), P_{13}(1720),
and P_{13}(1900) resonances for the description of the C_x and C_z data. A
brief discussion on the importance of these resonances is given. Measurements
of the polarized total cross section \sigma_{TT'} by the CLAS, LEPS, and MAMI
collaborations are expected to verify this finding.


title:
Faithful transformation of quasi-isotropic to Weyl-Papapetrou
  coordinates: A prerequisite to compare metrics

abstract:
  We demonstrate how one should transform correctly quasi-isotropic coordinates
to Weyl-Papapetrou coordinates in order to compare the metric around a rotating
star that has been constructed numerically in the former coordinates with an
axially symmetric stationary metric that is given through an analytical form in
the latter coordinates. Since a stationary metric associated with an isolated
object that is built numerically partly refers to a non-vacuum solution
(interior of the star) the transformation of its coordinates to Weyl-Papapetrou
coordinates, which are usually used to describe vacuum axisymmetric and
stationary solutions of Einstein equations, is not straightforward in the
non-vacuum region. If this point is \textit{not} taken into consideration, one
may end up to erroneous conclusions about how well a specific analytical metric
matches the metric around the star, due to fallacious coordinate
transformations.


title: Exceptional discretisations of the sine-Gordon equation

abstract:
  Recently, the method of one-dimensional maps was introduced as a means of
generating exceptional discretisations of the $\phi^4$-theories, i.e., discrete
$\phi^4$-models which support kinks centred at a continuous range of positions
relative to the lattice. In this paper, we employ this method to obtain
exceptional discretisations of the sine-Gordon equation (i.e. exceptional
Frenkel-Kontorova chains). We also use one-dimensional maps to construct a
discrete sine-Gordon equation supporting kinks moving with arbitrary velocities
without emitting radiation.


title: Eigenvalue Problem of Scalar Fields in BTZ Black Hole Spacetime

abstract:
  We studied the eigenvalue problem of scalar fields in the (2+1)-dimensional
BTZ black hole spacetime. The Dirichlet boundary condition at infinity and the
Dirichlet or the Neumann boundary condition at the horizon are imposed.
Eigenvalues for normal modes are characterized by the principal quantum number
$(0<n)$ and the azimuthal quantum number $(-\infty<m< \infty)$. Effects to
eigenvalues of the black hole rotation and of the scalar field mass are studied
explicitly. Relation of the black hole rotation to the super-radiant
instability is discussed.


title:
HD148937: a multiwavelength study of the third Galactic member of the
  Of?p class

abstract:
  Three Galactic O-type stars belong to the rare class of Of?p objects: HD108,
HD191612, and HD148937. The first two stars show a wealth of phenomena,
including magnetic fields and strong X-ray emission, light variability, and
dramatic periodic spectral variability. We present here the first detailed
optical and X-ray study of the third Galactic Of?p star, HD148937.
Spectroscopic monitoring has revealed low-level variability in the Balmer and
HeII4686 lines, but constancy at HeI and CIII4650. The Ha line exhibits profile
variations at a possible periodicity of ~7d. Model atmosphere fits yield
T_{eff}=41000+-2000K, log(g)=4.0+-0.1, Mdot_{sph}<~ 10^{-7}Msol/yr and a
surabondance of nitrogen by a factor of four. At X-ray wavelengths, HD148937
resembles HD108 and HD191612 in having a thermal spectrum dominated by a
relatively cool component (kT=0.2keV), broad lines (>1700km/s), and an
order-of-magnitude overluminosity compared to normal O stars (log
[L_X^unabs/L_BOL] ~ -6).


title:
Chiral radiative corrections in potential model and the P-wave states of
  heavy-light mesons

abstract:
  In relativistic potential model of heavy-light mesons it is essential to
incorporate the chiral radiative corrections before comparing the model
predictions with data. Once the radiative corrections are taken into account
the potential model can explain the unusual mass spectra and absence of the
spin orbit-inversion in P-wave states.


title:
A study of the efficiency of the class of $W$-states as a quantum
  channel

abstract:
  Recently, a new class of $W$-states has been defined by Agarwal and Pati
\cite{agarwal} and it has been shown that they can be used as a quantum channel
for teleportation and superdense coding. In this work, we identify those
three-qubit states from the set of the new class of $W$-states which are most
efficient or suitable for quantum teleportation. We show that with some
probability $|W_1>=(1/2)(|100>+|010>+\sqrt{2}|001>)$ is best suited for
teleportation channel in the sense that it does not depend on the input state.


title: Lifetime of unstable hairy black holes

abstract:
  During the last two decades solutions of black holes with various types of
"hair" have been discovered. Remarkably, it has been established that many of
these hairy black holes are unstable-- under small perturbations the hair may
collapse. While the static sector of theories admitting hair is well explored
by now, our picture of the dynamical process of hair-shedding is still
incomplete. In this Letter we provide an important ingredient of the nonlinear
dynamics of hair collapse: we derive a universal lower bound on the lifetime of
hairy black holes. It is also shown that the amount of hair outside of a
black-hole horizon should be fundamentally bounded.


title: X-shooter: a medium-resolution, wide-band spectrograph for the VLT

abstract:
  X-shooter is the first second-generation instrument for the ESO Very Large
Telescope and will be installed in 2008. It is intended to become the most
powerful optical & near-infrared medium-resolution spectrograph in the world,
with a unique spectral coverage from 300 to 2500 nm in one shot. The X-shooter
consortium members are from Denmark, France, Italy, The Netherlands and ESO.


title: On the Approximate Eigenstructure of Time-Varying Channels

abstract:
  In this article we consider the approximate description of doubly--dispersive
channels by its symbol. We focus on channel operators with compactly supported
spreading, which are widely used to represent fast fading multipath
communication channels. The concept of approximate eigenstructure is
introduced, which measures the accuracy E_p of the approximation of the channel
operation as a pure multiplication in a given L_p-norm. Two variants of such an
approximate Weyl symbol calculus are studied, which have important applications
in several models for time--varying mobile channels. Typically, such channels
have random spreading functions (inverse Weyl transform) defined on a common
support U of finite non--zero size such that approximate eigenstructure has to
be measured with respect to certain norms of the spreading process. We derive
several explicit relations to the size |U| of the support. We show that the
characterization of the ratio of E_p to some L_q-norm of the spreading function
is related to weighted norms of ambiguity and Wigner functions. We present the
connection to localization operators and give new bounds on the ability of
localization of ambiguity functions and Wigner functions in U. Our analysis
generalizes and improves recent results for the case p=2 and q=1.


title: The Smooth Structure of the Space of Piecewise-Smooth Loops

abstract:
  We consider the problem of defining the structure of a smooth manifold on the
various spaces of piecewise-smooth loops in a smooth finite dimensional
manifold. We succeed for a particular type of piecewise-smooth loops.
  We also examine the action of the diffeomorphism group of the circle. It is
not a useful action on the manifold that we define. We consider how one might
fix this problem and conclude that it can only be done by completing to the
space of loops of bounded variation.


title: A search for Extragalactic Sources of Ultrahigh-Energy Cosmic Rays

abstract:
  Possible extragalactic sources of cosmic rays at energies above 4*10^{19} eV
detected with the Yakutsk array are sought. Correlation of the shower arrival
directions with objects from Veron's catalog that are located closer than 100
Mpc from the Earth confirms the observations at the Pierre Auger observatory,
as well as the Greisen-Zatsepin-Kuzmin effect on ultrahigh-energy cosmic rays.
The detailed analysis of the data reveals the classes of objects belonging to
the active galactic nuclei that are probable sources of ultrahigh-energy cosmic
rays.


title:
Channel Estimation Theory of Low-Noise Multiple Parameters:Attainablity
  Problem of the Cram{\'e}r-Rao Bounds

abstract:
  For decoherence processes induced by weak interactions with the environment,
a general quantum channel with one noise parameter has been formulated. This
channel is called low-noise channel and very useful for investigating the
parameter estimation in the leading order. In this paper, we formulate the
low-noise channel with multiple unknown parameters in order to address the
simultaneous achievability of the Cram{\'e}r-Rao bound for the parameters
estimation. In general, the simultaneous achievement of the Cram{\'e}r-Rao
bound for multi-parameter estimations suffers from non-commutativity of optimal
measurements for respective parameters. However, with certain exceptions, we
show that the Cram{\'e}r-Rao bound for output states of dissipative low-noise
channels can be always attained in the first order of the parameters as long as
D \leq N-1, where D and N denote the number of the parameters and the dimension
of the system, respectively. This condition is replaced by D \leq N^{2}-1 if it
is allowed to set the entanglement with ancilla systems in its input state and
to perform the non-local measurement on the composite system.


title: Fitness, chance, and myths: an objective view on soccer results

abstract:
  We analyze the time series of soccer matches in a model-free way using data
for the German soccer league (Bundesliga). We argue that the goal difference is
a better measure for the overall fitness of a team than the number of points.
It is shown that the time evolution of the table during a season can be
interpreted as a random walk with an underlying constant drift. Variations of
the overall fitness mainly occur during the summer break but not during a
season. The fitness correlation shows a long-time decay on the scale of a
quarter century. Some typical soccer myths are analyzed in detail. It is shown
that losing but no winning streaks exist. For this analysis ideas from
multidimensional NMR experiments have been borrowed. Furthermore, beyond the
general home advantage there is no statistically relevant indication of a
team-specific home fitness. Based on these insights a framework for a
statistical characterization of the results of a soccer league is introduced
and some general consequences for the prediction of soccer results are
formulated.


title:
Frequency Dependence of Diagonal Resistance in Fractional Quantum Hall
  Effect via Periodic Modulation of Magnetic Field

abstract:
  Energy spectrum of fractional quantum Hall (FQH) states is composed of single
electron energy (Landau energy) neglecting the Coulomb interactions between
electrons, classical Coulomb energy and the quantum energy via quantum
transitions. Herein, the sum of the Landau energy and the classical Coulomb
energy depends upon the value of the filling factor continuously. However, the
quantum transition energy discontinuously depends upon the value of the filling
factor. This discontinuity yields energy gaps in many stable FQH states. The
energy gaps for specific filling factors produce the precise confinement of
Hall resistance.
  A new experiment is considered as follows; the magnetic strength is fixed to
the value to confine the Hall resistance at the filling factor of 2/3 as an
example. Moreover the magnetic modulation with frequency f is applied to the
system. The frequency dependence of the diagonal resistance is measured. Then,
it is shown in this paper that the diagonal resistance varies drastically at
some frequency value f0. We clarify the following relation between this value
f0 and the magnetic strength width dB of Hall plateaus as f0 = e dB / (4 Pi m),
where -e is the charge of electron, Pi =3.141592, and m is the mass of
electron.


title:
Reproducibility of Non-X-ray Background for the X-ray Imaging
  Spectrometer aboard Suzaku

abstract:
  One of the advantages of the X-ray Imaging Spectrometer (XIS) system on board
Suzaku is its low and stable non-X-ray background (NXB). In order to make the
best use of this advantage, modeling the NXB spectra with high accuracy is
important to subtract them from the spectra of on-source observations. We
construct an NXB database by collecting XIS events when the dark Earth covers
the XIS FOV. The total exposure time of the NXB data is about 785 ks for each
XIS. It is found that the count rate of the NXB anti-correlates with the
cut-off-rigidity and correlates with the count rate of the PIN upper
discriminator (PIN-UD) in Hard X-ray Detector on board Suzaku. We thus model
the NXB spectrum for a given on-source observation by employing either of these
parameters and obtain a better reproducibility of the NXB for the model with
PIN-UD than that with the cut-off-rigidity. The reproducibility of the NXB
model with PIN-UD is 4.55-5.63% for each XIS NXB in the 1-7 keV band and
2.79-4.36% for each XIS NXB in the 5-12 keV band for each 5 ks exposure of the
NXB data. This NXB reproducibility is much smaller than the spatial fluctuation
of the cosmic X-ray background in the 1-7 keV band, and is almost comparable to
that in the 5-12 keV band.


title:
Quantum dynamics of one and two bosonic atoms in a combined
  tight-binding periodic and weak parabolic potential

abstract:
  Strongly interacting bosonic particles in a tight-binding periodic potential
superimposed by a weak parabolic trap is a paradigm for many cold atom
experiments. Here, after revisiting the single particle problem, we study
interaction-bound dimers of bosonic atoms in the combined lattice and parabolic
potential. We consider both repulsively- and attractively-bound dimers and find
pronounced differences in their behaviour. We identify conditions under which
attractive and repulsive dimers exhibit analogous dynamics. Our studies reveal
that coherent transport and periodic oscillations of appropriately prepared
one- and two-atom wavepackets can be achieved, which may facilitate information
transfer in optical lattice based quantum computation schemes.


title: Families of zero cycles and divided powers: I. Representability

abstract:
  For any separated algebraic space $X/S$ we construct a separated algebraic
space $\Gamma^d(X/S)$ -- the space of divided powers -- which parameterizes
zero cycles of degree $d$ on $X$. The space of divided powers for an affine
scheme is given by the spectrum of the algebra of divided powers. In
characteristic zero or when $X/S$ is flat, the constructed space coincides with
the symmetric product $Sym^d(X/S)$. We also prove several fundamental results
on the kernels of multiplicative polynomial laws necessary for the construction
of $\Gamma^d(X/S)$.


title:
Structural, vibrational and quasiparticle properties of the Peierls
  semiconductor $\rm BaBiO_3$: a hybrid functional and self-consistent
  GW+vertex-corrections study

abstract:
  $\rm BaBiO_3$ is characterized by a charge disproportionation with half of
the Bi atoms possessing a valence 3+ and half a valence 5+. Because of
selfinteraction errors, local and semi-local density functionals fail to
describe the charge disproportionation quantitatively, yielding a too small
structural distortion and no band gap. Using hybrid functionals we obtain a
satisfactory description of the structural, electronic, optical, and
vibrational properties of $\rm BaBiO_3$. The results obtained using GW (Green's
function G and screened Coulomb potential W) based schemes on top of hybrid
functionals, including fully selfconsistent GW calculations with vertex
corrections in the dielectric screening, qualitatively confirm the HSE picture
but a systematic overestimation of the bandgap by about 0.4 eV is observed.


title:
The Simplest Determination of the Thermodynamical Characteristics of
  Schwarzschild, Kerr Andreissner-Nordstrom Black Hole

abstract:
  In this work, generalizing our previous results, we determine in an original
and the simplest way three most important thermodynamical characteristics
(Bekenstein-Hawking entropy, Bekenstein quantization of the entropy or (outer)
horizon surface area and Hawking temperature) of Schwarzschild, Kerr and
Reissner-Nordstrom black hole. We start physically by assumption that
circumference of black hole (outer) horizon holds the natural (integer) number
of corresponding reduced Compton's wave length and use mathematically only
simple algebraic equations. (It is conceptually similar to Bohr's quantization
postulate in Bohr's atomic model interpreted by de Broglie relation.)


title: Rotation and massive close binary evolution

abstract:
  We review the role of rotation in massive close binary systems. Rotation has
been advocated as an essential ingredient in massive single star models.
However, rotation clearly is most important in massive binaries where one star
accretes matter from a close companion, as the resulting spin-up drives the
accretor towards critical rotation. Here, we explore our understanding of this
process, and its observable consequences. When accounting for these
consequences, the question remains whether rotational effects in massive single
stars are still needed to explain the observations.


title: Positivity of cotangent bundles

abstract:
  In this paper we prove a generalization of a theorem of Schneider, which
gives a criterion for a projective surface over the complex numbers to have an
ample cotangent bundle. After reviewing different notions of positivity, we
introduce a slightly weaker notion of ampleness, which we call quasi-ample, and
then are able to extend Schneider's result to higher dimensions.