title: VLT/SINFONI Integral Field Spectroscopy of The Super-antennae

abstract:
  We present the results of H- and K-band VLT/SINFONI integral field
spectroscopy of the ULIRG IRAS 19254-7245 (The Super-antennae), an interacting
double galaxy system containing an embedded AGN. Deep K-band spectroscopy
reveals PaAlpha arising in a warped disc with position angle of 330 degree and
an inclination i=40-55 degree. The kinemetric parameters derived for H2 are
similar to PaAlpha. Two high-ionization emission lines, [SiVI] and [AlIX], are
detected and we identify as [NiII] the line observed at 1.94 micron. Diluting
non-stellar continuum, which was previously detected, has decayed, and the
H-band continuum emission is consistent with pure stellar emission. Based on H2
emission line ratios it is likely that at the central 1-kpc region H2 is
excited by UV fluorescence in dense clouds while shock excitation is dominant
further out. This scenario is supported by very low PaAlpha to H2 line ratio
detected outside the nuclear region and non-thermal ortho/para ratios (~2.0 -
2.5) close to the nucleus.


title:
WIMP Gamma Rays From the Galactic Center with GLAST and Accelerator
  Comparison

abstract:
  We will describe the prospects for detecting gamma-rays from WIMP's
annihilation in the Galactic Center and we compare this search with the
possibilities at LHC and with space antimatter experiments like PAMELA.


title:
Cavity losses for the dissipative Jaynes-Cummings Hamiltonian beyond
  Rotating Wave Approximation

abstract:
  A microscopic derivation of the master equation for the
  Jaynes-Cummings model with cavity losses is given, taking into account the
terms in the dissipator which vary with frequencies of the order of the vacuum
Rabi frequency. Our approach allows to single out physical contexts wherein the
usual phenomenological dissipator turns out to be fully justified and
constitutes an extension of our previous analysis [Scala M. {\em et al.} 2007
Phys. Rev. A {\bf 75}, 013811], where a microscopic derivation was given in the
framework of the Rotating Wave Approximation.


title: On permutation polytopes

abstract:
  A permutation polytope is the convex hull of a group of permutation matrices.
In this paper we investigate the combinatorics of permutation polytopes and
their faces. As applications we completely classify permutation polytopes in
dimensions 2,3,4, and the corresponding permutation groups up to a suitable
notion of equivalence. We also provide a list of combinatorial types of
possibly occuring faces of permutation polytopes up to dimension four.


title: Bandwidth Selection for Weighted Kernel Density Estimation

abstract:
  In the this paper, the authors propose to estimate the density of a targeted
population with a weighted kernel density estimator (wKDE) based on a weighted
sample. Bandwidth selection for wKDE is discussed. Three mean integrated
squared error based bandwidth estimators are introduced and their performance
is illustrated via Monte Carlo simulation. The least-squares cross-validation
method and the adaptive weight kernel density estimator are also studied. The
authors also consider the boundary problem for interval bounded data and apply
the new method to a real data set subject to informative censoring.


title: Frequency and damping of the Scissors Mode of a Fermi gas

abstract:
  We calculate the frequency and damping of the scissors mode in a classical
gas as a function of temperature and coupling strength. Our results show good
agreement with the main features observed in recent measurements of the
scissors mode in an ultracold gas of $^6$Li atoms. The comparison between
theory and experiment involves no fitting parameters and thus allows an
identification of non-classical effects at and near the unitarity limit.


title:
Yield scaling, size hierarchy and fluctuations of observables in
  fragmentation of excited heavy nuclei

abstract:
  Multifragmentation properties measured with INDRA are studied for single
sources produced in Xe+Sn reactions in the incident energy range 32-50 A MeV
and quasiprojectiles from Au+Au collisions at 80 A MeV. A comparison for both
types of sources is presented concerning Fisher scaling, Zipf law, fragment
size and fluctuation observables. A Fisher scaling is observed for all the
data. The pseudo-critical energies extracted from the Fisher scaling are
consistent between Xe+Sn central collisions and Au quasi-projectiles. In the
latter case it also corresponds to the energy region at which fluctuations are
maximal. The critical energies deduced from the Zipf analysis are higher than
those from the Fisher analysis.


title: Vector modes generated by primordial density fluctuations

abstract:
  While vector modes are usually ignored in cosmology since they are not
produced during inflation they are inevitably produced from the interaction of
density fluctuations of differing wavelengths. This effect may be calculated
via a second-order perturbative expansion. We investigate this effect during
the radiation era. We discuss the generation mechanism by investigating two
scalar modes interacting, and we calculate the power of vector modes generated
by a power-law spectrum of density perturbations on all scales.


title:
Quantum Stephani exact cosmological solutions and the selection of time
  variable

abstract:
  We study perfect fluid Stephani quantum cosmological model. In the present
work the Schutz's variational formalism which recovers the notion of time is
applied. This gives rise to Wheeler-DeWitt equation for the scale factor. We
use the eigenfunctions in order to construct wave packets for each case. We
study the time-dependent behavior of the expectation value of the scale factor,
using many-worlds and deBroglie-Bohm interpretations of quantum mechanics.


title:
On the Configuration Spaces of Homogeneous Loop Quantum Cosmology and
  Loop Quantum Gravity

abstract:
  The set of homogeneous isotropic connections, as used in loop quantum
cosmology, forms a line $l$ in the space of all connections $\cal A$. This
embedding, however, does not continuously extend to an embedding of the
configuration space $\overline l$ of homogeneous isotropic loop quantum
cosmology into that of loop quantum gravity, $\overline{\cal A}$. This follows
from the fact that the parallel transports for general, non-straight paths in
the base manifold do not depend almost periodically on $l$. Analogous results
are given for the anisotropic case.


title:
Dark Energy, scalar-curvature couplings and a critical acceleration
  scale

abstract:
  We study the effects of coupling a cosmologically rolling scalar field to
higher order curvature terms. We show that when the strong coupling scale of
the theory is on the 10^{-3}-10^{-1}eV range, the model passes all experimental
bounds on the existence of fifth forces even if the field has a mass of the
order of the Hubble scale in vacuum and non-suppressed couplings to SM fields.
The reason is that the coupling to certain curvature invariant acts as an
effective mass that grows in regions of large curvature. This prevents the
field from rolling down its potential near sources and makes its effects on
fifth-force search experiments performed in the laboratory to be observable
only at the sub-mm scale. We obtain the static spherically symmetric solutions
of the theory and show that a long-range force appears but it is turned on only
below a fixed Newtonian acceleration scale of the order of the Hubble constant.
We comment on the possibility of using this feature of the model to alleviate
the CDM small scale crisis and on its possible relation to MOND.


title: Dynamic correlations in an ordered c(2$\times$2) lattice gas

abstract:
  We obtain the dynamic correlation function of two-dimensional lattice gas
with nearest-neighbor repulsion in ordered c(2$\times$2) phase
(antiferromagnetic ordering) under the condition of low concentration of
structural defects. It is shown that displacements of defects of the ordered
state are responsible for the particle number fluctuations in the probe area.
The corresponding set of kinetic equations is derived and solved in linear
approximation on the defect concentration. Three types of strongly correlated
complex jumps are considered and their contribution to fluctuations is
analysed. These are jumps of excess particles, vacancies and flip-flop jumps.
The kinetic approach is more general than the one based on diffusion-like
equations used in our previous papers. Thus, it becomes possible to adequately
describe correlations of fluctuations at small times, where our previous theory
fails to give correct results. Our new analytical results for fluctuations of
particle number in the probe area agree well with those obtained by Monte Carlo
simulations.


title: Black Hole Thermodynamics and the Factor of 2 Problem

abstract:
  We show that the recent tunneling formulas for black hole radiation in
static, spherically symmetric spacetimes follow as a consequence of the first
law of black hole thermodynamics and the area-entropy relation based on the
radiation temperature. A tunneling formula results even if the radiation
temperature is different from the one originally derived by Hawking and this is
discussed in the context of the recent factor of 2 problem. In particular, it
is shown that if the radiation temperature is higher than the Hawking
temperature by a factor of two, thermodynamics then leads to a tunneling
formula which is exactly the one recently found to be canonically invariant.


title:
On the possibility of Dark Energy from corrections to the Wheeler-De
  Witt equation

abstract:
  We present a method for approximating the effective consequence of generic
quantum gravity corrections to the Wheeler-DeWitt equation. We show that in
many cases these corrections can produce departures from classical physics at
large scales and that this behaviour can be interpreted as additional matter
components. This opens up the possibility that dark energy (and possible dark
matter) could be large scale manifestations of quantum gravity corrections to
classical general relativity. As a specific example we examine the first order
corrections to the Wheeler-De Witt equation arising from loop quantum cosmology
in the absence of lattice refinement and show how the ultimate breakdown in
large scale physics occurs.


title:
Astrometry of Water Maser Sources in Nearby Molecular Clouds with VERA -
  II. SVS 13 in NGC 1333

abstract:
  We report on the results of multi-epoch VLBI observations with VERA (VLBI
Exploration of Radio Astrometry) of the 22 GHz H2O masers associated with the
young stellar object SVS 13 in the NGC 1333 region. We have carried out
phase-referencing VLBI astrometry and measured an annual parallax of the maser
features in SVS 13 of 4.25+/-0.32 mas, corresponding to the distance of
235+/-18 pc from the Sun. Our result is consistent with a photometric distance
of 220 pc previously reported. Even though the maser features were detectable
only for 6 months, the present results provide the distance to NGC 1333 with
much higher accuracy than photometric methods. The absolute positions and
proper motions have been derived, revealing that the H2O masers with the LSR
(local standard of rest) velocities of 7-8 km s-1 are most likely associated
with VLA4A, which is a radio counterpart of SVS 13. The origin of the observed
proper motions of the maser features are currently difficult to attribute to
either the jet or the rotating circumstellar disk associated with VLA4A, which
should be investigated through future high-resolution astrometric observations
of VLA4A and other radio sources in NGC 1333.


title: Formulas of F-thresholds and F-jumping coefficients on toric rings

abstract:
  F-thresholds are defined by Mustata, Takagi and Watanabe in [F-thresholds and
Bernstein-Sato polynomials], which are invariants of the pair of ideals on
rings of characteristic $p$. In their paper, it is proved F-thresholds equal to
jumping numbers for the test ideal on regular local rings. In this note, we
give an formula of F-thresholds on toric rings. This formula is a
generalization of the example in [Huneke, Mustata, Takagi and
Watanabe:F-thresholds, tight closure, integral closure, and multiplicity
bounds]. We prove that there exists an inequality between F-jumping
coefficients and F-thresholds. In particular, we observe a comparison between
F-pure thresholds and F-thresholds. As applications, we prove the
characterization of regularity for toric rings defined by a simplicial cone,
and the rationality of F-thresholds in some cases.


title: On the nonextensive character of some magnetic systems

abstract:
  During the past few years, nonextensive statistics has been successfully
applied to explain many different kinds of systems. Through these studies some
interpretations of the entropic parameter q, which has major role in this
statistics, in terms of physical quantities have been obtained. The aim of the
present work is to yield an overview of the applications of nonextensive
statistics to complex problems such as inhomogeneous magnetic systems.


title: Disordered pinning models and copolymers: beyond annealed bounds

abstract:
  We consider a general model of a disordered copolymer with adsorption. This
includes, as particular cases, a generalization of the copolymer at a selective
interface introduced by Garel et al. [Europhys. Lett. 8 (1989) 9--13], pinning
and wetting models in various dimensions, and the Poland--Scheraga model of DNA
denaturation. We prove a new variational upper bound for the free energy via an
estimation of noninteger moments of the partition function. As an application,
we show that for strong disorder the quenched critical point differs from the
annealed one, for example, if the disorder distribution is Gaussian. In
particular, for pinning models with loop exponent $0<\alpha<1/2$ this implies
the existence of a transition from weak to strong disorder. For the copolymer
model, under a (restrictive) condition on the law of the underlying renewal, we
show that the critical point coincides with the one predicted via
renormalization group arguments in the theoretical physics literature. A
stronger result holds for a "reduced wetting model" introduced by Bodineau and
Giacomin [J. Statist. Phys. 117 (2004) 801--818]: without restrictions on the
law of the underlying renewal, the critical point coincides with the
corresponding renormalization group prediction.


title:
Comment on ``Can Black Holes be Torn Up by a Phantom in Cyclic
  Cosmology?" by X. Zhang. arXiv:0708.1408 [gr-qc]

abstract:
  In a recently archived paper by Zhang\cite{Zhang}, it is claimed that before
turnaround in a cyclic model two unexpected events happen: (1) black holes
cease to contract and begin to expand; (2) separated causal patches start to
reconnect. We show that both conclusions are erroneous and result from the
author's choice of variables.


title: Size-dependent Surface States on Strained Cobalt Nanoislands on Cu(111)

abstract:
  Low-temperature scanning tunneling spectroscopy over Co nanoislands on
Cu(111) showed that the surface states of the islands vary with their size.
Occupied states exhibit a sizeable downward energy shift as the island size
decreases. The position of the occupied states also significantly changes
across the islands. Atomic-scale simulations and ab inito calculations
demonstrate that the driving force for the observed shift is related to
size-dependent mesoscopic relaxations in the nanoislands.


title: Sterile Neutrinos as the Warm Dark Matter in the Type II Seesaw Model

abstract:
  In the framework of type II seesaw mechanism we discuss the number of sterile
right-handed Majorana neutrinos being the warm dark matter (WDM). When the type
II seesaw mass term $M_\nu ^{II}$ is far less than the type I seesaw mass term
$M_\nu ^{I}$, only one of three sterile neutrinos may be the WDM particle. On
the contrary, the WDM particles may contain all sterile neutrinos. If $M_\nu
^{II} \sim M_\nu ^{I}$, the allowed number is not more than $N - 1$ for $N$
sterile neutrinos. It is worthwhile to stress that three different types of
neutrino mass spectrum are permitted when $M_\nu ^{II} \gg M_\nu ^{I}$ and
$M_\nu ^{II} \sim M_\nu ^{I}$.


title: Three-Particle Azimuthal Correlations

abstract:
  Two-particle azimuthal correlations in central Au+Au collisional at RHIC have
revealed a broadened away-side structure, with respect to perpherial Au+Au, pp,
and d+Au. This could be explained by different physics mechanisms such as:
large angle gluon radiation, deflected jets, Cerenkov gluon radiation, and
conical flow generated by hydrodynamic shock-waves. We can discriminate the
scenarios with conical emission, Cerenkov radiation and conical flow, from the
other mechanisms though three-particle correlations. In addition, the
associated particle pT dependence can be used to distinguish conical flow from
simple Cerenkov gluon radiation. We will discuss three-particle correlation
analyses that have been performed at RHIC and what can be done at the LHC.


title:
GaN:$\delta$-Mg grown by MOVPE: structural properties and their effect
  on the electronic and optical behaviour

abstract:
  The effect of Mg $\delta$-doping on the structural, electrical and optical
properties of GaN grown $\textsl{via}$ metalorganic vapor phase epitaxy has
been studied using transmission electron microscopy, secondary ion mass
spectroscopy, atomic force microscopy, x-ray diffraction, Hall effect
measurements and photoluminescence. For an average Mg concentration above 2.14
$\times$ 10$^{19}$ cm$^{-3}$, phase segregation occurs, as indicated by the
presence of Mg-rich pyramidal inversion domains in the layers. We show that
$\delta$-doping promotes, in comparison to Mg continuous doping, the
suppression of extended defects on the samples surface and improves
significantly the morphology of the epilayers. Conversely, we can not confirm
the reduction in the threading dislocation density - as a result of
$\delta$-doping - reported by other authors. In the phase separation regime,
the hole concentration is reduced with increasing Mg concentration, due to
self-compensation mechanisms. Below the solubility limit of Mg into GaN at our
growth conditions, potential fluctuations result in a red-shift of the emission
energy of the free-to-bound transition.


title: Gaudin functions, and Euler-Poincar\'e characteristics

abstract:
  Given two positive integers n,r, we define the Gaudin function of level r to
be quotient of the numerator of the determinant det(1/ ((x_i-y_j)(x_i-ty_j) ...
(x_i-t^r y_j)), i,j=1..n, by the two Vandermonde in x and y. We show that it
can be characterized by specializing the x-variables into the y-variables,
multiplied by powers of t. This allows us to obtain the Gaudin function of
level 1 (due to Korepin and Izergin) as the image of a resultant under the the
Euler-Poincar\'e characteristics of the flag manifold. As a corollary, we
recover a result of Warnaar about the generating function of Macdonald
polynomials.


title: Dark-Matter Content of Early-Type Galaxies with Planetary Nebulae

abstract:
  We examine the dark matter properties of nearby early-type galaxies using
planetary nebulae (PNe) as mass probes. We have designed a specialised
instrument, the Planetary Nebula Spectrograph (PN.S) operating at the William
Herschel telescope, with the purpose of measuring PN velocities with best
efficiency. The primary scientific objective of this custom-built instrument is
the study of the PN kinematics in 12 ordinary round galaxies. Preliminary
results showing a dearth of dark matter in ordinary galaxies (Romanowsky et al.
2003) are now confirmed by the first complete PN.S datasets. On the other hand
early-type galaxies with a "regular" dark matter content are starting to be
observed among the brighter PN.S target sample, thus confirming a correlation
between the global dark-to-luminous mass virial ratio (f_DM=M_DM/M_star) and
the galaxy luminosity and mass.


title: Photon propagator for axion electrodynamics

abstract:
  The axion modified electrodynamics is usually used as a model for description
of possible violation of Lorentz invariance in field theory. The low-energy
manifestation of Lorentz violation can hopefully be observed in experiments
with the electromagnetic waves. It justifies the importance of study how a
small axion addition can modify the wave propagation. Although a constant axion
does not contribute to the dispersion relation at all, even a slowly varying
axion field destroys the light cone structure. In this paper, we study the wave
propagation in the axion modified electrodynamics in the framework of premetric
approach. In an addition to the modified dispersion relation, we derive the
axion generalization of the photon propagator in Feynman and Landau gauge. Our
consideration is free from the usual restriction of a usual restriction to the
constant gradient axion field. It is remarkable that the axion modified
propagator is hermitian. Consequently the dissipation effects absent even in
the phenomenological model considered here.


title:
Cosmological implications of a supersymmetric extension of the
  Brans-Dicke theory

abstract:
  In the Brans-Dicke theory the Planck mass is replaced by a dynamical scalar
field. We consider here the supersymmetric analogous of this mechanism
replacing in the supergravity Lagrangian the Planck mass with a chiral
superfield. This analysis is motivated by the research of possible connections
between supersymmetric Dark Matter scenarios and Dark Energy models based on
Brans-Dicke-like theories. We find that, contrary to the original Brans-Dicke
theory, in its supersymmetric analogous the gravitational sector does not
couple to the matter sector in a universal metric way. As a result, violations
of the weak equivalence principle could be present in such a scenario.


title: Lefschetz fibrations and symplectic homology

abstract:
  We show that for each k > 3 there are infinitely many finite type Stein
manifolds diffeomorphic to Euclidean space R^{2k} which are pairwise distinct
as symplectic manifolds.


title:
Estimation of Missing Data Using Computational Intelligence and Decision
  Trees

abstract:
  This paper introduces a novel paradigm to impute missing data that combines a
decision tree with an auto-associative neural network (AANN) based model and a
principal component analysis-neural network (PCA-NN) based model. For each
model, the decision tree is used to predict search bounds for a genetic
algorithm that minimize an error function derived from the respective model.
The models' ability to impute missing data is tested and compared using HIV
sero-prevalance data. Results indicate an average increase in accuracy of 13%
with the AANN based model's average accuracy increasing from 75.8% to 86.3%
while that of the PCA-NN based model increasing from 66.1% to 81.6%.


title: Geant4 applications in the heliospheric radiation environment

abstract:
  The high energy ionizing radiation environment in the solar system consists
of three main sources: the radiation belts, galactic cosmic rays and solar
energetic particles. Geant4 is a Monte Carlo radiation transport simulation
toolkit, with applications in areas as high energy physics, nuclear physics,
astrophysics or medical physics research. In this poster, Geant4 applications
to model and study the effects of the heliospheric radiation environment are
presented. Specific applications are being developed to study the effect of the
radiation environment on detector components, to describe the response and to
optimise the design of radiation monitors for future space missions and to
predict the radiation environment in Mars surface, orbits and moons.


title:
A devil's staircase from rotations and irrationality measures for
  Liouville numbers

abstract:
  From Sturmian and Christoffel words we derive a strictly increasing function
$\Delta:[0,\infty)\to\mathbb{R}$. This function is continuous at every
irrational point, while at rational points, left-continuous but not
right-continuous. Moreover, it assumes algebraic integers at rationals, and
transcendental numbers at irrationals. We also see that the differentiation of
$\Delta$ distinguishes some irrationality measures of real numbers.


title:
Which mechanism underlies the water-like anomalies in core-softened
  potentials?

abstract:
  Using molecular dynamics simulations we investigate the thermodynamic of
particles interacting with a continuous and a discrete versions of a
core-softened (CS) intermolecular potential composed by a repulsive shoulder.
Dynamic and structural properties are also analyzed by the simulations. We show
that in the continuous version of the CS potential the density at constant
pressure has a maximum for a certain temperature. Similarly the diffusion
constant, $D$, at a constant temperature has a maximum at a density
$\rho_{\mathrm{max}}$ and a minimum at a density
$\rho_{\mathrm{min}}<\rho_{\mathrm{max}}$, and structural properties are also
anomalous. For the discrete CS potential none of these anomalies are observed.
The absence of anomalies in the discrete case and its presence in the
continuous CS potential are discussed in the framework of the excess entropy.


title: On the Area Functional of the Second Fundamental Form of Ovaloids

abstract:
  The expression for the variation of the area functional of the second
fundamental form of a hypersurface in a Euclidean space involves the so-called
"mean curvature of the second fundamental form". Several new characteristic
properties of (hyper)spheres, in which the mean curvature of the second
fundamental form occurs, are given. In particular, it is shown that the spheres
are the only ovaloids which are a critical point of the area functional of the
second fundamental form under various constraints.


title: On Zeta Functions and Families of Siegel Modular Forms

abstract:
  Let $p$ be a prime, and let $\Gamma=\Sp_g(\Z)$ be the Siegel modular group of
genus $g$. We study $p$-adic families of zeta functions and Siegel modular
forms. $L$-functions of Siegel modular forms are described in terms of motivic
$L$-functions attached to $\Sp_g$, and their analytic properties are given.
Critical values for the spinor $L$-functions and $p$-adic constructions are
discussed. Rankin's lemma of higher genus is established. A general conjecture
on a lifting from $ GSp_{2m} \times GSp_{2m}$ to $GSp_{4m}$ (of genus $g=4m$)
is formulated. Constructions of $p$-adic families of Siegel modular forms are
given using Ikeda-Miyawaki constructions.


title:
Energy, Rapidity and Transverse Momentum Dependence of Multiplicity
  Fluctuations in Heavy Ion Collisions at CERN SPS

abstract:
  Multiplicity fluctuations in the forward hemisphere were studied for
positively, negatively and all charged hadrons produced in central Pb+Pb
collisions at 20A, 30A, 40A, 80A and 158A GeV. The multiplicity distributions
and their scaled variances are presented as a function of collision energy,
rapidity and transverse momentum. The distributions have a bell-like shape and
the scaled variance changes monotonously with energy in the range from 0.8 to
1.2. No indication of the critical point is observed.
  The string-hadronic model UrQMD reproduces results on the scaled variance.
The predictions of the hadron-resonance gas model obtained within the
grand-canonical and canonical ensembles for the scaled variance disagree with
the data.


title: Unfolding Restricted Convex Caps

abstract:
  This paper details an algorithm for unfolding a class of convex polyhedra,
where each polyhedron in the class consists of a convex cap over a rectangular
base, with several restrictions: the cap's faces are quadrilaterals, with
vertices over an underlying integer lattice, and such that the cap convexity is
``radially monotone,'' a type of smoothness constraint. Extensions of Cauchy's
arm lemma are used in the proof of non-overlap.


title:
Asymptotics: Particles, Processes and Inverse Problems. Festschrift for
  Piet Groeneboom

abstract:
  In September 2006, Piet Groeneboom officially retired as professor of
statistics at Delft University of Technology and the Vrije Universiteit in
Amsterdam. He did so by delivering his farewell lecture `Summa Cogitatio' ([42]
in Piet's publication list) in the Aula of the university in Delft. To
celebrate Piet's impressive contributions to statistics and probability, the
workshop `Asymptotics: particles, processes and inverse problems' was held from
July 10 until July 14, 2006, at the Lorentz Center in Leiden. Many leading
researchers in the fields of probability and statistics gave talks at this
workshop, and it became a memorable event for all who attended, including the
organizers and Piet himself. This volume serves as a Festschrift for Piet
Groeneboom. It contains papers that were presented at the workshop as well as
some other contributions, and it represents the state of the art in the areas
in statistics and probability where Piet has been (and still is) most active.
Furthermore, a short CV of Piet Groeneboom and a list of his publications are
included.


title: The Vertical Structure of Planet-induced Gaps in Proto-Planetary Discs

abstract:
  Giant planets embedded in circumstellar discs are expected to open gaps in
these discs. We examine the vertical structure of the gap edges. We find that
the planet excites spiral arms with significant (Mach number of a half)
vertical motion of the gas, and discuss the implications of these motions. In
particular, the spiral arms will induce strong vertical stirring of the dust,
making the edge appeared `puffed up' relative to the bulk of the disc.
Infra-red observations (sensitive to dust) would be dominated by the light from
the thick inner edge of the disc. Sub-millimetre observations (sensitive to gas
velocities) would appear to be hot in `turbulent' motions (actually the ordered
motion caused by the passage of the spiral arms), but cold in chemistry.
Resolved sub-millimetre maps of circumstellar discs might even be able to
detect the spiral arms directly.


title: Gapless superconductivity and the Fermi arc in the cuprates

abstract:
  We argue that the Fermi arc observed in angle resolved photoemission
measurements in underdoped cuprates can be understood as a consequence of
inelastic scattering in a d-wave superconductor. We analyze this phenomenon in
the context of strong coupling Eliashberg theory, deriving a `single lifetime'
model for describing the temperature evolution of the spectral gap as measured
by single particle probes such as photoemission and tunneling.


title: Local distinguishability of orthogonal 2\otimes3 pure states

abstract:
  We present a complete characterization for the local distinguishability of
orthogonal $2\otimes 3$ pure states except for some special cases of three
states. Interestingly, we find there is a large class of four or three states
that are indistinguishable by local projective measurements and classical
communication (LPCC) can be perfectly distinguishable by LOCC. That indicates
the ability of LOCC for discriminating $2\otimes 3$ states is strictly more
powerful than that of LPCC, which is strikingly different from the case of
multi-qubit states. We also show that classical communication plays a crucial
role for local distinguishability by constructing a class of $m\otimes n$
states which require at least $2\min\{m,n\}-2$ rounds of classical
communication in order to achieve a perfect local discrimination.


title: Top Quarks, Axigluons and Charge Asymmetries at Hadron Colliders

abstract:
  Axigluons are colored heavy neutral gauge boson that couple to quarks through
an axial vector current and the same strong coupling as gluons. The most
important model-independent manifestation of axigluons is the generation of a
forward--backward asymmetry in top-antitop quark production at $p\bar{p}$
collisions which originates from the charge asymmetry. We update our previous
analysis for the inclusive QCD induced forward--backward asymmetry and define a
new observable which is more sensitive to the effect than the forward--backward
asymmetry. Furthermore, we find a lower limit of 1.2 TeV at 90% C.L. on the
axigluon mass from recent measurements of the asymmetry at Tevatron. Also at
LHC, the charge asymmetry is sizable in suitably selected samples. We evaluate
this asymmetry in the central region for different selection cuts and show
that, like at Tevatron, the charge asymmetry can probe larger values of the
axigluon mass than the dijet mass distribution.


title:
Counterexamples to continuity of optimal transportation on positively
  curved Riemannian manifolds

abstract:
  Counterexamples to continuity of optimal transportation on Riemannian
manifolds with everywhere positive sectional curvature are provided. These
examples show that the condition A3w of Ma, Trudinger, & Wang is not guaranteed
by positivity of sectional curvature.


title:
Localizing the Elliott Conjecture at Strongly Self-absorbing C*-algebras
  --An Appendix

abstract:
  This note provides some technical support to the proof of a result of W.
Winter which shows that two unital separable simple amenable ${\cal
Z}$-absorbing C*-algebras with locally finite decomposition property satisfying
the UCT whose projections separate the traces are isomorphic if their
$K$-theory is finitely generated and their Elliott invariants are the same.


title: Network structure and dynamics of hydrogenated amorphous silicon

abstract:
  In this paper we discuss the application of current it ab initio computer
simulation techniques to hydrogenated amorphous silicon (a-Si:H). We begin by
discussing thermal fluctuation in the number of coordination defects in the
material, and its temperature dependence. We connect this to the ``fluctuating
bond center detachment" mechanism for liberating H bonded to Si atoms. Next,
from extended thermal MD simulation, we illustrate various mechanisms of H
motion. The dynamics of the lattice is then linked to the electrons, and we
point out that the squared electron-lattice coupling (and the thermally-induced
mean square variation in electron energy eigenvalues) is robustly proportional
to the localization of the conjugate state, if localization is measured with
inverse participation ratio. Finally we discuss the Staebler-Wronski effect
using these methods, and argue that a sophisticated local heating picture
(based upon reasonable calculations of the electron-lattice coupling and
molecular dynamic simulation) explains significant aspects of the phenomenon.


title:
Detection of a Third Planet in the HD 74156 System Using the
  Hobby-Eberly Telescope

abstract:
  We report the discovery of a third planetary mass companion to the G0 star HD
74156. High precision radial velocity measurements made with the Hobby-Eberly
Telescope aided the detection of this object. The best fit triple Keplerian
model to all the available velocity data yields an orbital period of 347 days
and minimum mass of 0.4 M_Jup for the new planet. We determine revised orbital
periods of 51.7 and 2477 days, and minimum masses of 1.9 and 8.0 M_Jup
respectively for the previously known planets. Preliminary calculations
indicate that the derived orbits are stable, although all three planets have
significant orbital eccentricities (e = 0.64, 0.43, and 0.25). With our
detection, HD 74156 becomes the eighth normal star known to host three or more
planets. Further study of this system's dynamical characteristics will likely
give important insight to planet formation and evolutionary processes.


title:
Time-evolution of ionization and heating around first stars and
  miniquasars

abstract:
  A one dimensional radiative transfer code is developed to track the
ionization and heating pattern around the first miniquasars and Population III
stars. The code follows the evolution of the ionization of the species of
hydrogen and helium and the intergalactic medium temperature profiles as a
function of redshift. The radiative transfer calculations show that the
ionization signature of the first miniquasars and stars is very similar yet the
heating pattern around the two is very different. Furthermore, the first
massive miniquasars (~>10^5 M_{sun}) do produce large ionized bubbles around
them, which can potentially be imaged directly using future radio telescopes.
It is also shown that the ionized bubbles not only stay ionized for
considerable time after the switching off of the source, but continue to expand
for a short while due to secondary collisions prompted by the X-ray part of
their spectra. Varying spectral shapes also produced sizable variations in
ionized fraction and temperature profile. We also compare the radiative
transfer results with the analytical approximation usually adopted for heating
by miniquasars and find that, because of the inadequate treatment of the He
species, the analytical approach leads to an underestimation of the temperature
in the outer radii by a factor ~5. Population III stars - with masses in the
range of 10 - 1000 M_{sun} and modelled as blackbodies at a temperature of
50000 K - are found to be efficient in ionizing their surroundings.
Observational effects on the 21 cm brightness temperature, the thermal and
kinetic Sunyaev-Ze'ldovich effects, are also studied in the context of the
upcoming radio and microwave telescopes like LOFAR and SPT.


title:
New path description for the M(k+1,2k+3) models and the dual Z_k graded
  parafermions

abstract:
  We present a new path description for the states of the non-unitary
M(k+1,2k+3) models. This description differs from the one induced by the
Forrester-Baxter solution, in terms of configuration sums, of their
restricted-solid-on-solid model. The proposed path representation is actually
very similar to the one underlying the unitary minimal models M(k+1,k+2), with
an analogous Fermi-gas interpretation. This interpretation leads to fermionic
expressions for the finitized M(k+1,2k+3) characters, whose infinite-length
limit represent new fermionic characters for the irreducible modules. The
M(k+1,2k+3) models are also shown to be related to the Z_k graded parafermions
via a (q to 1/q) duality transformation.

categories: hep-th cond-mat.stat-mech math-ph math.CO math.MP


title:
On the localized phase of a copolymer in an emulsion: supercritical
  percolation regime

abstract:
  In this paper we study a two-dimensional directed self-avoiding walk model of
a random copolymer in a random emulsion. The copolymer is a random
concatenation of monomers of two types, $A$ and $B$, each occurring with
density 1/2. The emulsion is a random mixture of liquids of two types, $A$ and
$B$, organised in large square blocks occurring with density $p$ and $1-p$,
respectively, where $p \in (0,1)$. The copolymer in the emulsion has an energy
that is minus $\alpha$ times the number of $AA$-matches minus $\beta$ times the
number of $BB$-matches, where without loss of generality the interaction
parameters can be taken from the cone $\{(\alpha,\beta)\in\R^2\colon \alpha\geq
|\beta|\}$. To make the model mathematically tractable, we assume that the
copolymer is directed and can only enter and exit a pair of neighbouring blocks
at diagonally opposite corners.
  In \cite{dHW06}, it was found that in the supercritical percolation regime $p
\geq p_c$, with $p_c$ the critical probability for directed bond percolation on
the square lattice, the free energy has a phase transition along a curve in the
cone that is independent of $p$. At this critical curve, there is a transition
from a phase where the copolymer is fully delocalized into the $A$-blocks to a
phase where it is partially localized near the $AB$-interface. In the present
paper we prove three theorems that complete the analysis of the phase diagram :
(1) the critical curve is strictly increasing; (2) the phase transition is
second order; (3) the free energy is infinitely differentiable throughout the
partially localized phase.


title: Partial Gr\"obner bases for multiobjective integer linear optimization

abstract:
  In this paper we present a new methodology for solving multiobjective integer
linear programs using tools from algebraic geometry. We introduce the concept
of partial Gr\"obner basis for a family of multiobjective programs where the
right-hand side varies. This new structure extends the notion of Gr\"obner
basis for the single objective case, to the case of multiple objectives, i.e.,
a partial ordering instead of a total ordering over the feasible vectors. The
main property of these bases is that the partial reduction of the integer
elements in the kernel of the constraint matrix by the different blocks of the
basis is zero. It allows us to prove that this new construction is a test
family for a family of multiobjective programs. An algorithm '\`a la
Buchberger' is developed to compute partial Gr\"obner bases and two different
approaches are derived, using this methodology, for computing the entire set of
efficient solutions of any multiobjective integer linear problem (MOILP). Some
examples illustrate the application of the algorithms and computational
experiments are reported on several families of problems.


title: Bulk dominated fermion emission on a Schwarzschild background

abstract:
  Using the WKBJ approximation, and the Unruh method, we obtain semi-analytic
expressions for the absorption probability (in all energy regimes) for Dirac
fermions on a higher dimensional Schwarzschild background. We present an
analytic expression relating the absorption probability to the absorption
cross-section, and then use these results to plot the emission rates to third
order in the WKBJ approximation. The set-up we use is sufficiently general such
that it could also easily be applied to any spherically symmetric background in
$d$-dimensions. Our results lead to the interesting conclusion that for $d>5$
bulk fermion emission dominates brane localised emission. This is an example
contrary to the conjecture that black holes radiate mainly on the brane.


title:
Teleportation of qubit states through dissipative channels: Conditions
  for surpassing the no-cloning limit

abstract:
  We investigate quantum teleportation through dissipative channels and
calculate teleportation fidelity as a function of damping rates. It is found
that the average fidelity of teleportation and the range of states to be
teleported depend on the type and rate of the damping in the channel. Using the
fully entangled fraction, we derive two bounds on the damping rates of the
channels: one is to beat the classical limit and the second is to guarantee the
non-existence of any other copy with better fidelity. Effect of the initially
distributed maximally entangled state on the process is presented; and the
concurrence and the fully entangled fraction of the shared states are
discussed. We intend to show that prior information on the dissipative channel
and the range of qubit states to be teleported is helpful for the evaluation of
the success of teleportation, where success is defined as surpassing the
fidelity limit imposed by the fidelity of 1-to-2 optimal cloning machine for
the specific range of qubits.


title:
Uniform Bahadur Representation for Local Polynomial Estimates of
  M-Regression and Its Application to The Additive Model

abstract:
  We use local polynomial fitting to estimate the nonparametric M-regression
function for strongly mixing stationary processes
$\{(Y_{i},\underline{X}_{i})\}$. We establish a strong uniform consistency rate
for the Bahadur representation of estimators of the regression function and its
derivatives. These results are fundamental for statistical inference and for
applications that involve plugging in such estimators into other functionals
where some control over higher order terms are required. We apply our results
to the estimation of an additive M-regression model.


title: Multiplicity Studies and Effective Energy in ALICE at the LHC

abstract:
  In this work we explore the possibility to perform ``effective energy''
studies in very high energy collisions at the CERN Large Hadron Collider (LHC).
In particular, we focus on the possibility to measure in $pp$ collisions the
average charged multiplicity as a function of the effective energy with the
ALICE experiment, using its capability to measure the energy of the leading
baryons with the Zero Degree Calorimeters. Analyses of this kind have been done
at lower centre--of--mass energies and have shown that, once the appropriate
kinematic variables are chosen, particle production is characterized by
universal properties: no matter the nature of the interacting particles, the
final states have identical features. Assuming that this universality picture
can be extended to {\it ion--ion} collisions, as suggested by recent results
from RHIC experiments, a novel approach based on the scaling hypothesis for
limiting fragmentation has been used to derive the expected charged event
multiplicity in $AA$ interactions at LHC. This leads to scenarios where the
multiplicity is significantly lower compared to most of the predictions from
the models currently used to describe high energy $AA$ collisions. A mean
charged multiplicity of about 1000-2000 per rapidity unit (at $\eta \sim 0$) is
expected for the most central $Pb-Pb$ collisions at $\sqrt{s_{NN}} = 5.5 TeV$.


title: On some new congruences for binomial coefficients

abstract:
  In this paper we establish some new congruences involving central binomial
coefficients as well as Catalan numbers. Let $p$ be a prime and let $a$ be any
positive integer. We determine $\sum_{k=0}^{p^a-1}\binom{2k}{k+d}$ mod $p^2$
for $d=0,...,p^a$ and $\sum_{k=0}^{p^a-1}\binom{2k}{k+\delta}$ mod $p^3$ for
$\delta=0,1$. We also show that
$$C_n^{-1}\sum_{k=0}^{p^a-1}C_{p^an+k}=1-3(n+1)((p^a-1)/3) (mod p^2)$$ for
every n=0,1,2,..., where $C_m$ is the Catalan number $\binom{2m}{m}/(m+1)$, and
(-) is the Legendre symbol.


title: Inductive acceleration of UHECRs in sheared relativistic jets

abstract:
  Relativistic outflows carrying large scale magnetic fields have large
inductive potential and may accelerate protons to ultra high energies. We
discuss a novel scheme of Ultra-High Energy Cosmic Ray (UHECR) acceleration due
to drifts in magnetized, cylindrically collimated, sheared jets of powerful
active galaxies (with jet luminosity $\geq 10^{46}$ erg s$^{-1}$). A positively
charged particle carried by such a plasma is in an unstable equilibrium if
${\bf B} \cdot \nabla \times {\bf v}< 0$, so that kinetic drift along the
velocity shear would lead to fast, regular energy gain. The highest rigidity
particles are accelerated most efficiently implying the dominance of light
nuclei for energies above the ankle in our model: from a mixed population of
pre-accelerated particle the drift mechanism picks up and boosts protons
preferably.


title:
Solving Constraint Satisfaction Problems through Belief
  Propagation-guided decimation

abstract:
  Message passing algorithms have proved surprisingly successful in solving
hard constraint satisfaction problems on sparse random graphs. In such
applications, variables are fixed sequentially to satisfy the constraints.
Message passing is run after each step. Its outcome provides an heuristic to
make choices at next step. This approach has been referred to as `decimation,'
with reference to analogous procedures in statistical physics.
  The behavior of decimation procedures is poorly understood. Here we consider
a simple randomized decimation algorithm based on belief propagation (BP), and
analyze its behavior on random k-satisfiability formulae. In particular, we
propose a tree model for its analysis and we conjecture that it provides
asymptotically exact predictions in the limit of large instances. This
conjecture is confirmed by numerical simulations.

categories: cs.AI cond-mat.dis-nn cond-mat.stat-mech cs.CC


title: Anomalies in gauge theory and gerbes over quotient stacks

abstract:
  We give a new interpretation of the Faddeev-Mickelsson anomaly in certain
Yang-Mills theories in terms of S^1-central extensions of Lie groupoids.


title: Mott transition of fermionic atoms in a three-dimensional optical trap

abstract:
  We study theoretically the Mott metal-insulator transition for a system of
fermionic atoms confined in a three-dimensional optical lattice and a harmonic
trap. We describe an inhomogeneous system of several thousand sites using an
adaptation of dynamical mean field theory solved efficiently with the numerical
renormalization group method. Above a critical value of the on-site
interaction, a Mott-insulating phase appears in the system. We investigate
signatures of the Mott phase in the density profile and in time-of-flight
experiments.


title:
On approximate solutions of semilinear evolution equations II.
  Generalizations, and applications to Navier-Stokes equations

abstract:
  In our previous paper [12] (Rev. Math. Phys. 16, 383-420 (2004)), a general
framework was outlined to treat the approximate solutions of semilinear
evolution equations; more precisely, a scheme was presented to infer from an
approximate solution the existence (local or global in time) of an exact
solution, and to estimate their distance. In the first half of the present work
the abstract framework of \cite{uno} is extended, so as to be applicable to
evolutionary PDEs whose nonlinearities contain derivatives in the space
variables. In the second half of the paper this extended framework is applied
to theincompressible Navier-Stokes equations, on a torus T^d of any dimension.
In this way a number of results are obtained in the setting of the Sobolev
spaces H^n(T^d), choosing the approximate solutions in a number of different
ways. With the simplest choices we recover local existence of the exact
solution for arbitrary data and external forces, as well as global existence
for small data and forces. With the supplementary assumption of exponential
decay in time for the forces, the same decay law is derived for the exact
solution with small (zero mean) data and forces. The interval of existence for
arbitrary data, the upper bounds on data and forces for global existence, and
all estimates on the exponential decay of the exact solution are derived in a
fully quantitative way (i.e., giving the values of all the necessary constants;
this makes a difference with most of the previous literature). Nextly, the
Galerkin approximate solutions are considered and precise, still quantitative
estimates are derived for their H^n distance from the exact solution; these are
global in time for small data and forces (with exponential time decay of the
above distance, if the forces decay similarly).


title: Gribov copies and confinement

abstract:
  We analyse the role of the Gribov ambiguity in the construction of physical
charges in gauge theories. It is shown explicitly how the Gribov copies prevent
the construction of physical coloured charges beyond perturbation theory. We
also present a new and manifestly non-perturbative class of Coulomb gauge
Gribov copies.


title: Explore Physics Beyond the Standard Model with GLAST

abstract:
  We give an overview of the possibility of GLAST to explore theories beyond
the Standard Model of particle physics. Among the wide taxonomy we will focus
in particular on low scale supersymmetry and theories with extra space-time
dimensions. These theories give a suitable dark matter candidate whose
interactions and composition can be studied using a gamma ray probe. We show
the possibility of GLAST to disentangle such exotic signals from a standard
production background.


title: Gravitational Higgs Mechanism and Massive Gravity

abstract:
  In arXiv:hep-th/0011245, in the context of domain wall backgrounds, it was
shown that spontaneous breaking of diffeomorphism invariance results in
gravitational Higgs mechanism. Recently in arXiv:0708.3184 't Hooft discussed
gravitational Higgs mechanism in the context of obtaining massive gravity
directly in four dimensions, and pointed out some subtleties with unitarity. We
attribute these subtleties to breaking time-like diffeomorphisms, and discuss
gravitational Higgs mechanism with all but time-like diffeomorphisms
spontaneously broken. The resulting background is no longer flat but exhibits
expansion, which is linear in time. For space-time dimensions D <= 10 the
background is stable and has no non-unitary propagating modes. The absence of
non-unitary modes is due to the unbroken time-like diffeomorphism invariance.
The physical states correspond to those of a massive graviton. The effective
mass squared of the graviton is positive for D < 10, and vanishes for D = 10.
For D > 10 the graviton modes become effectively tachyonic. The special value
of D=10, which coincides with the critical dimension of superstring theory,
arises in our setup completely classically.


title:
Matrix-Lifting Semi-Definite Programming for Decoding in Multiple
  Antenna Systems

abstract:
  This paper presents a computationally efficient decoder for multiple antenna
systems. The proposed algorithm can be used for any constellation (QAM or PSK)
and any labeling method. The decoder is based on matrix-lifting Semi-Definite
Programming (SDP). The strength of the proposed method lies in a new relaxation
algorithm applied to the method of Mobasher et al. This results in a reduction
of the number of variables from $(NK+1)^2$ to $(2N+K)^2$, where $N$ is the
number of antennas and $K$ is the number of constellation points in each real
dimension. Since the computational complexity of solving SDP is a polynomial
function of the number of variables, we have a significant complexity
reduction. Moreover, the proposed method offers a better performance as
compared to the best quasi-maximum likelihood decoding methods reported in the
literature.


title:
Indirect control of the asymptotic states of a quantum dynamical
  semigroup

abstract:
  In the dynamics of open quantum systems, the interaction with the external
environment usually leads to a contraction of the set of reachable states for
the system as time increases, eventually shrinking to a single stationary
point. In this contribution we describe to what extent it is possible to modify
this asymptotic state by means of indirect control, that is by using an
auxiliary system coupled to the target system in order to affect its dynamics,
when there is a purely dissipative coupling between the two systems. We prove
that, also in this restrictive case, it is possible to modify the asymptotic
state of the relevant system, give necessary conditions for that and provide
physical examples. Therefore, in indirect control schemes, the environmental
action has not only a negative impact on the dynamics of a system, it is rather
possible to make use of it for control purposes.


title: What is a metric space?

abstract:
  The question in the title is discussed briefly, with emphasis on a few basic
examples and their properties.


title: A remark on Frobenius descent for vector bundles

abstract:
  We give a class of examples of vector bundles on a relative smooth projective
curve over Spec Z such that for infinitely many prime reductions the bundle has
a Frobenius descent, but the restriction to the generic fiber in characteristic
zero is not semistable. In the third section of the paper we prove for a large
class of varieties (including abelian varieties) that any vector bundle with
this Frobenius descent property is generically semistable.


title: Asymptotic integration and dispersion for hyperbolic equations

abstract:
  The aim of this paper is to establish time decay properties and dispersive
estimates for strictly hyperbolic equations with homogeneous symbols and with
time-dependent coefficients whose derivatives are integrable. For this purpose,
the method of asymptotic integration is developed for such equations and
representation formulae for solutions are obtained. These formulae are analysed
further to obtain time decay of Lp-Lq norms of propagators for the
corresponding Cauchy problems. It turns out that the decay rates can be
expressed in terms of certain geometric indices of the limiting equation and we
carry out the thorough analysis of this relation. This provides a comprehensive
view on asymptotic properties of solutions to time-perturbations of hyperbolic
equations with constant coefficients. Moreover, we also obtain the time decay
rate of the Lp-Lq estimates for equations of these kinds, so the time
well-posedness of the corresponding nonlinear equations with additional
semilinearity can be treated by standard Strichartz estimates.


title:
The extremal values of the Wiener index of a tree with given degree
  sequence

abstract:
  The Wiener index of a graph is the sum of the distances between all pairs of
vertices, it has been one of the main descriptors that correlate achemical
compound's molecular graph with experimentally gathered data regarding the
compound's characteristics. The tree that minimizes the Wiener index among
trees of given maximal degree was studied. We characterize trees that achieve
the maximum and minimum Wiener index, given the number of vertices and the
degree sequence.


title:
Towards new background independent representations for Loop Quantum
  Gravity

abstract:
  Recently, uniqueness theorems were constructed for the representation used in
Loop Quantum Gravity. We explore the existence of alternate representations by
weakening the assumptions of the so called LOST uniqueness theorem. The
weakened assumptions seem physically reasonable and retain the key requirement
of explicit background independence. For simplicity, we restrict attention to
the case of gauge group U(1).


title: Fractional dynamical systems and applications in mechanics and economics

abstract:
  Using the fractional integration and differentiation on R we build the
fractional jet fibre bundle on a differentiable manifold and we emphasize some
important geometrical objects. Euler-Lagrange fractional equations are
described. Some significant examples from mechanics and economics are
presented.


title: Quantum risk-sensitive estimation and robustness

abstract:
  This paper studies a quantum risk-sensitive estimation problem and
investigates robustness properties of the filter. This is a direct extension to
the quantum case of analogous classical results. All investigations are based
on a discrete approximation model of the quantum system under consideration.
This allows us to study the problem in a simple mathematical setting. We close
the paper with some examples that demonstrate the robustness of the
risk-sensitive estimator.


title:
Failure of the displaced-squeezed state for spin-boson models in the
  thermodynamic limit

abstract:
  We present an analysis of a variational coherent-squeezed state that has been
discussed in the literature as a potential ground state for the spin-boson
model. We show that when the system-size scaling of the spin-bath coupling is
included properly, all squeezing effects and non-universal physics vanish in
the thermodynamic limit. We also present finite-size corrections to the
renormalisation of the spin's coherence, showing that squeezing effects are
also absent to leading order in the inverse bath-size.


title: Thermal Charm Production in Quark-Gluon Plasma at LHC

abstract:
  Charm production from the quark-gluon plasma created in the midrapidity of
central heavy ion collisions at the Large Hadron Collider (LHC) is studied in
the next-to-leading order in QCD. Using a schematic longitudinally
boost-invariant and transversally expanding fire-cylinder model, we find that
charm production could be appreciably enhanced at LHC as a result of the high
temperature that is expected to be reached in the produced quark-gluon plasma.
Sensitivities of our results to the number of charm quark pairs produced from
initial hard scattering, the initial thermalization time and temperature of the
quark-gluon plasma, and the charm quark mass are also studied.


title: Entropies for complex systems: generalized-generalized entropies

abstract:
  Many complex systems are characterized by non-Boltzmann distribution
functions of their statistical variables. If one wants to -- justified or not
-- hold on to the maximum entropy principle for complex statistical systems
(non-Boltzmann) we demonstrate how the corresponding entropy has to look like,
given the form of the corresponding distribution functions. By two natural
assumptions that (i) the maximum entropy principle should hold and that (ii)
entropy should describe the correct thermodynamics of a system (which produces
non-Boltzmann distributions) the existence of a class of fully consistent
entropies can be deduced. Classical Boltzmann-Gibbs entropy is recovered as a
special case for the observed distribution being the exponential, Tsallis
entropy is the special case for q-exponential observations.


title:
Colliding Stellar Wind Models with Nonequilibrium Ionization: X-rays
  from WR 147

abstract:
  The effects of nonequilibrium ionization are explicitly taken into account in
a numerical model which describes colliding stellar winds (CSW) in massive
binary sytems. This new model is used to analyze the most recent X-ray spectra
of the WR+OB binary system WR 147. The basic result is that it can adequately
reproduce the observed X-ray emission (spectral shape, observed flux) but some
adjustment in the stellar wind parameters is required. Namely, (i) the stellar
wind velocities must be higher by a factor of 1.4 - 1.6; (ii) the mass loss
must be reduced by a factor of ~ 2. The reduction factor for the mass loss is
well within the uncertainties for this parameter in massive stars, but given
the fact that the orbital parameters (e.g., inclination angle and eccentricity)
are not well constrained for WR 147, even smaller corrections to the mass loss
might be sufficient. Only CSW models with nonequilibrium ionization and equal
(or nearly equal) electron and ion postshock temperature are successful.
Therefore, the analysis of the X-ray spectra of WR 147 provides evidence that
the CSW shocks in this object must be collisionless.


title: Co/Nb/Co low field superconducting spin switch

abstract:
  We report experiments on a superconducting spin switch based on
technologically relevant materials as elemental ferromagnetic Co and elemental
superconducting Nb. The Co/Nb/Co structure exhibits inverse spin switch effect,
can be operated at liquid helium temperature and can switch from
superconductive to normal state in rather weak applied magnetic fields.
Relevant critical currents as a function of temperature and magnetic field as
well as preparation of superconductive or resistive state are addressed here.


title: The Generalized Burnside Theorem

abstract:
  All groups have 2 generators. For every prime power q, the Generalized
Burnside Theorem (Theorem GB) produces an infinite number of solvable groups,
Some, such as groups of a prime power exponent, have only elements of finite
order and are therefore finite groups. Others have elements of infinite order
and are thus infinite groups.
  All these groups, even when infinite, are closely related to groups of
exponent q. They have at least one generator of order q, and their commutator
subgroup has exponent q.


title: Seifert surfaces, Commutators and Vassiliev invariants

abstract:
  We show that the Vassiliev invariants of a knot K, are obstructions to
finding a regular Seifert surface, S, whose complement looks "simple" (e.g.
like the complement of a disc) to the lower central series of its fundamental
group.


title:
Equilibrium and dynamics of a trapped superfluid Fermi gas with unequal
  masses

abstract:
  Interacting Fermi gases with equal populations but unequal masses are
investigated at zero temperature using local density approximation and the
hydrodynamic theory of superfluids in the presence of harmonic trapping.
  We derive the conditions of energetic stability of the superfluid
configuration with respect to phase separation and the frequencies of the
collective oscillations in terms of the mass ratio and the trapping frequencies
of the two components. We discuss the behavior of the gas after the trapping
potential of a single component is switched off and show that, near a Feshbach
resonance, the released component can still remain trapped due to many-body
interaction effects. Explicit predictions are presented for a mixture of $^6$Li
and $^{40}$K with resonant interaction.


title:
Microwave response of a cylindrical cavity made of bulk MgB2
  superconductor

abstract:
  We report on the microwave properties of a resonant cylindrical cavity made
of bulk MgB2 superconductor, produced by the reactive liquid Mg infiltration
process. The frequency response of the cavity has been measured in the range
5-13GHz. Among the various modes, the TE011, resonating at 9.79GHz, exhibits
the highest quality factor. For this mode, we have determined the temperature
dependence of the quality factor, obtaining values of the order of 10^5 in the
temperature range 4.2-30K. The values of the surface resistance deduced from
the measurements of the quality factor agree quite well with those
independently measured in a small sample of MgB2 extracted from the same
specimen from which the cavity has been obtained.


title:
Precision photometric redshift calibration for galaxy-galaxy weak
  lensing

abstract:
  Accurate photometric redshifts are among the key requirements for precision
weak lensing measurements. Both the large size of the Sloan Digital Sky Survey
(SDSS) and the existence of large spectroscopic redshift samples that are
flux-limited beyond its depth have made it the optimal data source for
developing methods to properly calibrate photometric redshifts for lensing.
Here, we focus on galaxy-galaxy lensing in a survey with spectroscopic lens
redshifts, as in the SDSS. We develop statistics that quantify the effect of
source redshift errors on the lensing calibration and on the weighting scheme,
and show how they can be used in the presence of redshift failure and sampling
variance. We then demonstrate their use with 2838 source galaxies with
spectroscopy from DEEP2 and zCOSMOS, evaluating several public photometric
redshift algorithms, in two cases including a full p(z) for each object, and
find lensing calibration biases as low as 1% (due to fortuitous cancellation of
two types of bias) or as high as 20% for methods in active use (despite the
small mean photoz bias of these algorithms). Our work demonstrates that
lensing-specific statistics must be used to reliably calibrate the lensing
signal, due to asymmetric effects of (frequently non-Gaussian) photoz errors.
We also demonstrate that large-scale structure (LSS) can strongly impact the
photoz calibration and its error estimation, due to a correlation between the
LSS and the photoz errors, and argue that at least two independent degree-scale
spectroscopic samples are needed to suppress its effects. Given the size of our
spectroscopic sample, we can reduce the galaxy-galaxy lensing calibration error
well below current SDSS statistical errors.


title:
Discovery of the accretion-powered millisecond pulsar SWIFT J1756.9-2508
  with a low-mass companion

abstract:
  We report on the discovery by the Swift Gamma-Ray Burst Explorer of the
eighth known transient accretion-powered millisecond pulsar, SWIFT
J1756.9-2508, as part of routine observations with the Swift Burst Alert
Telescope hard X-ray transient monitor. The pulsar was subsequently observed by
both the X-Ray Telescope on Swift and the Rossi X-Ray Timing Explorer
Proportional Counter Array. It has a spin frequency of 182 Hz (5.5 ms) and an
orbital period of 54.7 minutes. The minimum companion mass is between 0.0067
and 0.0086 solar masses, depending on the mass of the neutron star, and the
upper limit on the mass is 0.030 solar masses (95% confidence level). Such a
low mass is inconsistent with brown dwarf models, and comparison with white
dwarf models suggests that the companion is a He-dominated donor whose thermal
cooling has been at least modestly slowed by irradiation from the accretion
flux. No X-ray bursts, dips, eclipses or quasi-periodic oscillations were
detected. The current outburst lasted approximately 13 days and no earlier
outbursts were found in archival data.


title:
Successful ToO triggers on the extragalactic sources with the MAGIC
  telescope

abstract:
  The MAGIC collaboration has been performing Target of Opportunity (ToO)
observations whenever alerted that known or potential very high energy
gamma-ray emitting extragalactic sources were in a high flux state in the
optical, X-ray band or/and in the TeV energy range. Here we report on MAGIC
observations performed after such triggers, results of the analysis, and a
possible optical-TeV correlation seen in the data. Detections as well as
spectral and temporal characterestics of Mkn 180, PKS 2155-304, and 1ES
1011+496 are reported.


title: Dynamics of surface solitons at the edge of chirped optical lattices

abstract:
  We address soliton formation at the edge of chirped optical lattices
imprinted in Kerr-type nonlinear media. We find families of power thresholdless
surface waves that do not exist at other types of lattice interfaces. Such
solitons form due to combined action of internal reflection at the interface,
distributed Bragg-type reflection, and focusing nonlinearity. Remarkably, we
discover that surfaces of chirped lattices are soliton attractors: Below an
energy threshold, solitons launched well within the lattice self-bend toward
the interface, and then stick to it.


title:
A Generic Rate Equation for modeling Enzymatic Reactions under Living
  Conditions

abstract:
  Based on our experience in kinetic modeling of coupled multiple metabolic
pathways we propose a generic rate equation for the dynamical modeling of
metabolic kinetics. Its symmetric form makes the kinetic parameters (or
functions) easy to relate to values in database and to use in computation. In
addition, such form is workable to arbitrary number of substrates and products
with different stoichiometry. We explicitly show how to obtain such rate
equation exactly for various binding mechanisms. Hence the proposed rate
equation is formally rigorous. Various features of such a generic rate equation
are discussed. For irreversible reactions, the product inhibition which
directly arise from enzymatic reaction is eliminated in a natural way. We also
discuss how to include the effects of modifiers and cooperativity.


title:
Enhanced soliton interactions by inhomogeneous nonlocality and
  nonlinearity

abstract:
  We address the interactions between optical solitons in the system with
longitudinally varying nonlocality degree and nonlinearity strength. We
consider a physical model describing light propagation in nematic liquid
crystals featuring a strongly nonlocal nonlinear response. We reveal that the
variation of the nonlocality and nonlinearity along the propagation direction
can substantially enhance or weaken the interaction between out-of-phase
solitons. This phenomenon manifests itself as a slowdown or acceleration of the
soliton collision dynamics in one-dimensional geometries or of the soliton
spiraling rate in bulk media. Therefore, one finds that by engineering the
nonlocality and nonlinearity variation rate one can control the output soliton
location.


title:
Observation of the Semileptonic Decays B --> D* tau nubar and Evidence
  for B --> D tau nubar

abstract:
  We present measurements of the semileptonic decays B- --> D0 tau- nubar, B-
--> D*0 tau- nubar, B0bar --> D+ tau- nubar, and B0bar --> D*+ tau- nubar,
which are potentially sensitive to non--Standard Model amplitudes. The data
sample comprises 232x10^6 Upsilon(4S) --> BBbar decays collected with the BaBar
detector. From a combined fit to B- and B0bar channels, we obtain the branching
fractions B(B --> D tau- nubar) = (0.86 +/- 0.24 +/- 0.11 +/- 0.06)% and B(B
--> D* tau- nubar) = (1.62 +/- 0.31 +/- 0.10 +/- 0.05)% (normalized for the
B0bar), where the uncertainties are statistical, systematic, and
normalization-mode-related.


title: Efficient Tabling Mechanisms for Transaction Logic Programs

abstract:
  In this paper we present efficient evaluation algorithms for the Horn
Transaction Logic (a generalization of the regular Horn logic programs with
state updates). We present two complementary methods for optimizing the
implementation of Transaction Logic. The first method is based on tabling and
we modified the proof theory to table calls and answers on states (practically,
equivalent to dynamic programming). The call-answer table is indexed on the
call and a signature of the state in which the call was made. The answer
columns contain the answer unification and a signature of the state after the
call was executed. The states are signed efficiently using a technique based on
tries and counting. The second method is based on incremental evaluation and it
applies when the data oracle contains derived relations. The deletions and
insertions (executed in the transaction oracle) change the state of the
database. Using the heuristic of inertia (only a part of the state changes in
response to elementary updates), most of the time it is cheaper to compute only
the changes in the state than to recompute the entire state from scratch. The
two methods are complementary by the fact that the first method optimizes the
evaluation when a call is repeated in the same state, and the second method
optimizes the evaluation of a new state when a call-state pair is not found by
the tabling mechanism (i.e. the first method). The proof theory of Transaction
Logic with the application of tabling and incremental evaluation is sound and
complete with respect to its model theory.


title:
Finite temperature Mott transition in Hubbard model on anisotropic
  triangular lattice

abstract:
  We investigate the Hubbard model on the anisotropic triangular lattice by
means of the cellular dynamical mean field theory. The phase diagram determined
in the Hubbard interaction versus temperature plane shows novel reentrant
behavior in the Mott transition due to the competition between Fermi-liquid
formation and magnetic correlations under geometrical frustration. We
demonstrate that the reentrant behavior is characteristic of the Mott
transition with intermediate geometrical frustration and indeed consistent with
recent experimental results of organic materials.


title: Enrichment of Qualitative Beliefs for Reasoning under Uncertainty

abstract:
  This paper deals with enriched qualitative belief functions for reasoning
under uncertainty and for combining information expressed in natural language
through linguistic labels. In this work, two possible enrichments (quantitative
and/or qualitative) of linguistic labels are considered and operators
(addition, multiplication, division, etc) for dealing with them are proposed
and explained. We denote them $qe$-operators, $qe$ standing for
"qualitative-enriched" operators. These operators can be seen as a direct
extension of the classical qualitative operators ($q$-operators) proposed
recently in the Dezert-Smarandache Theory of plausible and paradoxist reasoning
(DSmT). $q$-operators are also justified in details in this paper. The
quantitative enrichment of linguistic label is a numerical supporting degree in
$[0,\infty)$, while the qualitative enrichment takes its values in a finite
ordered set of linguistic values. Quantitative enrichment is less precise than
qualitative enrichment, but it is expected more close with what human experts
can easily provide when expressing linguistic labels with supporting degrees.
Two simple examples are given to show how the fusion of qualitative-enriched
belief assignments can be done.


title: High-spin structure and Band Termination in $^{103}$Cd

abstract:
  Excited states of the neutron deficient $^{103}$Cd nucleus have been
investigated via the $^{72}$Ge($^{35}$Cl, p3n) reaction at beam energy of 135
MeV by use of in-beam spectroscopic methods. Gamma rays depopulating the
excited states were detected using the Gammasphere spectrometer with high-fold
$\gamma$-ray coincidences. A quadrupole $\gamma$-ray coincidence analysis
($\gamma^{4}$) has been used to extend the known level scheme. The positive
parity levels have been established up to $J = 35/2\hbar$ and $E_{x} = 7.071$
MeV. In addition to the observation of highly-fragmented level scheme belonging
to the positive-parity sequences at E$_{x}\sim$ 5 MeV, the termination of a
negative-parity sequence connected by $E2$ transitions has been established at
$J = 47/2 \hbar$ and $E_{x} = 11.877$ MeV. The experimental results
corresponding to both the positive- and negative-parity sequences have been
theoretically interpreted in the framework of the core particle coupling model.
Evidence is presented for a shape change from collective prolate to
non-collective oblate above the $J^{\pi} = 39/2^{-}$ (8011 keV) level and for a
smooth termination of the negative-parity band.


title:
Existence, uniqueness and approximation of a stochastic Schr\"odinger
  equation: the diffusive case

abstract:
  Recent developments in quantum physics make heavy use of so-called "quantum
trajectories." Mathematically, this theory gives rise to "stochastic
Schr\"odinger equations", that is, perturbation of Schr\"odinger-type equations
under the form of stochastic differential equations. But such equations are in
general not of the usual type as considered in the literature. They pose a
serious problem in terms of justifying the existence and uniqueness of a
solution, justifying the physical pertinence of the equations. In this article
we concentrate on a particular case: the diffusive case, for a two-level
system. We prove existence and uniqueness of the associated stochastic
Schr\"odinger equation. We physically justify the equations by proving that
they are a continuous-time limit of a concrete physical procedure for obtaining
a quantum trajectory.


title: Quantum simulation of the single-particle Schrodinger equation

abstract:
  The working of a quantum computer is described in the concrete example of a
quantum simulator of the single-particle Schrodinger equation. We show that a
register of 6-10 qubits is sufficient to realize a useful quantum simulator
capable of solving in an efficient way standard quantum mechanical problems.


title:
Charge-transfer exciton in La2CuO4 probed with resonant inelastic x-ray
  scattering

abstract:
  We report a high-resolution resonant inelastic x-ray scattering study of
La2CuO4. A number of spectral features are identified that were not clearly
visible in earlier lower-resolution data. The momentum dependence of the
spectral weight and the dispersion of the lowest energy excitation across the
insulating gap have been measured in detail. The temperature dependence of the
spectral features was also examined. The observed charge transfer edge shift,
along with the low dispersion of the first charge transfer excitation are
attributed to the lattice motion being coupled to the electronic system. In
addition, we observe a dispersionless feature at 1.8 eV, which is associated
with a d-d crystal field excitation.


title: Substrate-induced band gap opening in epitaxial graphene

abstract:
  Graphene has shown great application potentials as the host material for next
generation electronic devices. However, despite its intriguing properties, one
of the biggest hurdles for graphene to be useful as an electronic material is
its lacking of an energy gap in the electronic spectra. This, for example,
prevents the use of graphene in making transistors. Although several proposals
have been made to open a gap in graphene's electronic spectra, they all require
complex engineering of the graphene layer. Here we show that when graphene is
epitaxially grown on the SiC substrate, a gap of ~ 0.26 is produced. This gap
decreases as the sample thickness increases and eventually approaches zero when
the number of layers exceeds four. We propose that the origin of this gap is
the breaking of sublattice symmetry owing to the graphene-substrate
interaction. We believe our results highlight a promising direction for band
gap engineering of graphene.


title:
Magnetic Behavior of Single La$_{0.67}$Ca$_{0.33}$MnO$_3$ Nanotubes:
  Surface and Shape Effects

abstract:
  We report magnetization experiments in two magnetically isolated
ferromagnetic nanotubes of perovskite La$_{0.67}$Ca$_{0.33}$MnO$_3$. The
results show that the magnetic anisotropy is determined by the sample shape
although the coercive field is reduced by incoherent magnetization reversal
modes. The temperature dependence of the magnetization reveals that the
magnetic behavior is dominated by grain surface properties. These measurements
were acquired using a Silicon micro-mechanical oscillator working in its
resonant mode. The sensitivity was enough to measure the magnetic properties of
these two samples with a mass lower than 14 picograms and to obtain for the
first time the magnetization loop for one isolated nanotube.


title: Symplectic symmetries of 4-manifolds

abstract:
  A study of symplectic actions of a finite group $G$ on smooth 4-manifolds is
initiated. The central new idea is the use of $G$-equivariant
Seiberg-Witten-Taubes theory in studying the structure of the fixed-point set
of these symmetries. The main result in this paper is a complete description of
the fixed-point set structure (and the action around it) of a symplectic cyclic
action of prime order on a minimal symplectic 4-manifold with $c_1^2=0$.
Comparison of this result with the case of locally linear topological actions
is made. As an application of these considerations, the triviality of many such
actions on a large class of 4-manifolds is established. In particular, we show
the triviality of homologically trivial symplectic symmetries of a $K3$ surface
(in analogy with holomorphic automorphisms). Various examples and comments
illustrating our considerations are also included.


title: HST Observations of Chromospheres in Metal Deficient Field Giants

abstract:
  HST high resolution spectra of metal-deficient field giants more than double
the stars in previous studies, span about 3 magnitudes on the red giant branch,
and sample an abundance range [Fe/H]= -1 to -3. These stars, in spite of their
age and low metallicity, possess chromospheric fluxes of Mg II (2800 Angstrom)
that are within a factor of 4 of Population I stars, and give signs of a
dependence on the metal abundance at the lowest metallicities. The Mg II k-line
widths depend on luminosity and correlate with metallicity. Line profile
asymmetries reveal outflows that occur at lower luminosities (M_V = -0.8) than
detected in Ca K and H-alpha lines in metal-poor giants, suggesting mass
outflow occurs over a larger span of the red giant branch than previously
thought, and confirming that the Mg II lines are good wind diagnostics. These
results do not support a magnetically dominated chromosphere, but appear more
consistent with some sort of hydrodynamic, or acoustic heating of the outer
atmospheres.


title: Symmetries and exotic smooth structures on a $K3$ surface

abstract:
  Smooth and symplectic symmetries of an infinite family of distinct exotic
$K3$ surfaces are studied, and comparison with the corresponding symmetries of
the standard $K3$ is made. The action on the $K3$ lattice induced by a smooth
finite group action is shown to be strongly restricted, and as a result,
nonsmoothability of actions induced by a holomorphic automorphism of a prime
order $\geq 7$ is proved and nonexistence of smooth actions by several $K3$
groups is established (included among which is the binary tetrahedral group
$T_{24}$ which has the smallest order). Concerning symplectic symmetries, the
fixed-point set structure of a symplectic cyclic action of a prime order $\geq
5$ is explicitly determined, provided that the action is homologically
nontrivial.


title: A Hyperelliptic View on Teichmuller Space. I

abstract:
  We explicitly describe the Teichmuller space TH_n of hyperelliptic surfaces
in terms of natural and effective coordinates as the space of certain
(2n-6)-tuples of distinct points on the ideal boundary of the Poincare disc. We
essentially use the concept of a simple earthquake which is a particular case
of a Fenchel-Nielsen twist deformation. Such earthquakes generate a group that
acts transitively on TH_n. This fact can be interpreted as a continuous analog
of the well-known Dehn theorem saying that the mapping class group is generated
by Dehn twists. We find a simple and effective criterion that verifies if a
given representation of the surface group \pi_1\Sigma in the group of
isometries of the hyperbolic plane is faithful and discrete. The article also
contains simple and elementary proofs of several known results, for instance,
of W. M. Goldman's theorem [Gol1] characterizing the faithful discrete
representations as having maximal Toledo invariant (which is essentially the
area of the representation in the two-dimensional case).


title: Dissipation in intercluster plasma

abstract:
  We discuss dissipative processes in strongly gyrotropic, nearly collisionless
plasma in clusters of galaxies (ICM). First, we point out that Braginsky
theory, which assumes that collisions are more frequent that the system's
dynamical time scale, is inapplicable to fast, sub-viscous ICM motion. Most
importantly, the electron contribution to collisional magneto-viscosity
dominates over that of ions for short-scale Alfvenic motions. Thus, if a
turbulent cascade develops in the ICM and propagates down to scales $\leq 1$
kpc, it is damped collisionally not on ions, but on electrons. Second, in high
beta plasma of ICM, small variations of the magnetic field strength, of
relative value $\sim 1/\beta$, lead to development of anisotropic pressure
instabilities (firehose, mirror and cyclotron). Unstable wave modes may provide
additional resonant scattering of particles, effectively keeping the plasma in
a state of marginal stability. We show that in this case the dissipation rate
of a laminar, subsonic, incompressible flows scales as inverse of plasma beta
parameter. We discuss application to the problem of ICM heating.


title:
Millimeter Interferometric HCN(1-0) and HCO+(1-0) Observations of
  Luminous Infrared Galaxies

abstract:
  We present the results on millimeter interferometric observations of four
luminous infrared galaxies (LIRGs), Arp 220, Mrk 231, IRAS 08572+3915, and VV
114, and one Wolf-Rayet galaxy, He 2-10, using the Nobeyama Millimeter Array
(NMA). Both the HCN(1-0) and HCO+(1-0) molecular lines were observed
simultaneously and their brightness-temperature ratios were derived.
High-quality infrared L-band (2.8-4.1 micron) spectra were also obtained for
the four LIRGs to better constrain their energy sources deeply buried in dust
and molecular gas. When combined with other LIRGs we have previously observed
with NMA, the final sample comprised nine LIRGs (12 LIRGs' nuclei) with
available interferometric HCN(1-0) and HCO+(1-0) data-sufficient to investigate
the overall trend in comparison with known AGNs and starburst galaxies. We
found that LIRGs with luminous buried AGN signatures at other wavelengths tend
to show high HCN(1-0)/HCO+(1-0) brightness-temperature ratios as seen in
AGN-dominated galaxies, while the Wolf-Rayet galaxy He 2-10 displays a small
ratio. An enhanced HCN abundance in the interstellar gas surrounding a strongly
X-ray-emitting AGN, as predicted by some chemical calculations, is a natural
explanation of our results.


title: A GIM Mechanism from Extra Dimensions

abstract:
  We explore how to protect extra dimensional models from large flavor changing
neutral currents by using bulk and brane flavor symmetries. We show that a GIM
mechanism can be built in to warped space models such as Randall-Sundrum or
composite Higgs models if flavor mixing is introduced via UV brane kinetic
mixings for right handed quarks. We give a realistic implementation both for a
model with minimal flavor violation and one with next-to-minimal flavor
violation. The latter does not suffer from a CP problem. We consider some of
the existing experimental constraints on these models implied by precision
electroweak tests.


title:
Magnetically asymmetric interfaces in a (LaMnO$_3$)/(SrMnO$_3$)
  superlattice due to structural asymmetries

abstract:
  Polarized neutron reflectivity measurements of a ferromagnetic
[(LaMnO$_3$)$_{11.8}$/(SrMnO$_3$)$_{4.4}$]$_6$ superlattice reveal a modulated
magnetic structure with an enhanced magnetization at the interfaces where
LaMnO$_3$ was deposited on SrMnO$_3$ (LMO/SMO). However, the opposite
interfaces (SMO/LMO) are found to have a reduced ferromagnetic moment. The
magnetic asymmetry arises from the difference in lateral structural roughness
of the two interfaces observed via electron microscopy, with strong
ferromagnetism present at the interfaces that are atomically smooth over tens
of nanometers. This result demonstrates that atomic-scale roughness can
destabilize interfacial phases in complex oxide heterostructures.


title:
Consistent Determination of Particle Production in p-A, d-A and A-A
  Collisions using Color Glass Condensate

abstract:
  The success of nonviscous hydrodynamics in describing the collective flow
properties of bulk low $p_\perp$ observables at RHIC has led to the claim that
a novel form of {\it strongly coupled} Quark Gluon Plasma (sQGP) is created in
200 AGeV Au+Au collisions. This success depends strongly, however, on the
initial conditions assumed in the calculations. In particular, agreement with
data is only obtained assuming Glauber nuclear reaction plane (participant)
geometry. The KLN model of Color Glass Condenstate (CGC) initial conditions
require the existence of nonvanishing viscous effects. We develop an improved
model of CGC that is more internally consistent between the central and diffuse
edge regions. The improved model is shown to describe bulk rapidity
distributions for a wide assortment of system sizes, geometries and energies.
The self consistency forces a specific $\sqrt{s}$ dependence of the
multiplicity which leads to surprisingly low particle production predictions
for Pb+Pb collisions at LHC COM energies. These predictions are similar to
those made using simple linear extrapolations of multiplicity attempted by the
PHOBOS collaboration.


title: Lattice and Schroder paths with periodic boundaries

abstract:
  We consider paths in the plane with $(1,0),$ $(0,1),$ and $(a,b)$-steps that
start at the origin, end at height $n,$ and stay to the left of a given
non-decreasing right boundary. We show that if the boundary is periodic and has
slope at most $b/a,$ then the ordinary generating function for the number of
such paths ending at height $n$ is algebraic. Our argument is in two parts. We
use a simple combinatorial decomposition to obtain an Appell relation or
``umbral'' generating function, in which the power $z^n$ is replaced by a power
series of the form $z^n \phi_n(z),$ where $\phi_n(0) = 1.$ Then we convert (in
an explicit way) the umbral generating function to an ordinary generating
function by solving a system of linear equations and a polynomial equation.
This conversion implies that the ordinary generating function is algebraic.


title: A short-loop algorithm for quantum Monte Carlo simulations

abstract:
  We present an algorithmic framework for a variant of the quantum Monte Carlo
operator-loop algorithm, where non-local cluster updates are constructed in a
way that makes each individual loop smaller. The algorithm is designed to
increase simulation efficiency in cases where conventional loops become very
large, do not close altogether, or otherwise behave poorly. We demonstrate and
characterize some aspects of the short-loop on a square lattice spin-1/2 XXZ
model where, remarkably, a significant increase in simulation efficiency is
observed in some parameter regimes. The simplicity of the model provides a
prototype for the use of short-loops on more complicated quantum systems.

categories: cond-mat.stat-mech cond-mat.dis-nn cond-mat.mes-hall cond-mat.mtrl-sci cond-mat.other cond-mat.soft


title: Mean-field conditions for percolation on finite graphs

abstract:
  Let G_n be a sequence of finite transitive graphs with vertex degree d=d(n)
and |G_n|=n. Denote by p^t(v,v) the return probability after t steps of the
non-backtracking random walk on G_n. We show that if p^t(v,v) has quasi-random
properties, then critical bond-percolation on G_n has a scaling window of width
n^{-1/3}, as it would on a random graph.
  A consequence of our theorems is that if G_n is a transitive expander family
with girth at least (2/3 + eps) \log_{d-1} n, then the size of the largest
component in p-bond-percolation with p={1 +O(n^{-1/3}) \over d-1} is roughly
n^{2/3}. In particular, bond-percolation on the celebrated Ramanujan graph
constructed by Lubotzky, Phillips and Sarnak has the above scaling window. This
provides the first examples of quasi-random graphs behaving like random graphs
with respect to critical bond-percolation.


title: Environmentally-Driven Evolution of Simulated Cluster Galaxies

abstract:
  Galaxies in clusters are gas-deficient and a number of possible explanations
for this observation have been advanced, including galaxy-cluster tidal
interactions, galaxy harassment, and ISM-ICM gas stripping. In this paper, we
use a cosmological simulation of cluster formation and evolution in order to
examine this issue from a theoretical standpoint. We follow a large number of
galaxies over time and track each galaxy's gas and stellar mass changes to
discover what mechanism(s) dominate the evolution of the cluster galaxies. We
find that while gas is lost due to a wide variety of mechanisms, the most
common way is via a gas-only stripping event, and the amount of gas lost
correlates with the ram-pressure the galaxy is experiencing. Although this
gas-stripping occurs primarily in the central region (r < 1 Mpc), it is an
important mechanism out to the virial radius of the cluster. This is due to the
wide scatter in ram-pressure strength that a galaxy experiences at fixed
radius. We find that the timescale for complete gas removal is > 1 Gyr. In
addition, we find that galaxies in the field and in the cluster periphery (r >
2.4 Mpc) often accrete cool gas; the accretion stops between 1-2.4 Mpc,
possibly indicating the onset of galaxy starvation.


title:
Parallel marginalization Monte Carlo with applications to conditional
  path sampling

abstract:
  Monte Carlo sampling methods often suffer from long correlation times.
Consequently, these methods must be run for many steps to generate an
independent sample. In this paper a method is proposed to overcome this
difficulty. The method utilizes information from rapidly equilibrating coarse
Markov chains that sample marginal distributions of the full system. This is
accomplished through exchanges between the full chain and the auxiliary coarse
chains. Results of numerical tests on the bridge sampling and
filtering/smoothing problems for a stochastic differential equation are
presented.


title: Evolution of massive black holes

abstract:
  Supermassive black holes are nowadays believed to reside in most local
galaxies. Accretion of gas and black hole mergers play a fundamental role in
determining the two parameters defining a black hole: mass and spin. I briefly
review here some of the physical processes that are conducive to the evolution
of the massive black hole population. I'll discuss black hole formation
processes that are likely to place at early cosmic epochs, and how massive
black hole evolve in a hierarchical Universe. The mass of the black holes that
we detect today in nearby galaxy has mostly been accumulated by accretion of
gas. While black hole--black hole mergers do not contribute substantially to
the final mass of massive black holes, they influence the occupancy of galaxy
centers by black hole, owing to the chance of merging black holes being kicked
from their dwellings due to the gravitational recoil. Similarly, accretion
leaves a deeper imprint on the distribution of black hole spins than black hole
mergers do. The differences in accretion histories for black holes hosted in
elliptical or disc galaxies may reflect on different spin distributions.


title:
Statistical properties of one-dimensional maps with critical points and
  singularities

abstract:
  We prove that a class of one-dimensional maps with an arbitrary number of
non-degenerate critical and singular points admits an induced Markov tower with
exponential return time asymptotics. In particular the map has an absolutely
continuous invariant probability measure with exponential decay of correlations
for H\"{o}lder observations.


title: Effective interaction of exhausted regions in kinetics of nucleation

abstract:
  An effect of overlapping of exhausted regions around droplets of a new phase
is analyzed. Several approximation to take overlapping into account are
suggested. The small parameter responsible for convergence is extracted. The
multi particle effects of overlapping are described.


title: Volatility return intervals analysis of the Japanese market

abstract:
  We investigate scaling and memory effects in return intervals between price
volatilities above a certain threshold $q$ for the Japanese stock market using
daily and intraday data sets. We find that the distribution of return intervals
can be approximated by a scaling function that depends only on the ratio
between the return interval $\tau$ and its mean $<\tau>$. We also find memory
effects such that a large (or small) return interval follows a large (or small)
interval by investigating the conditional distribution and mean return
interval. The results are similar to previous studies of other markets and
indicate that similar statistical features appear in different financial
markets. We also compare our results between the period before and after the
big crash at the end of 1989. We find that scaling and memory effects of the
return intervals show similar features although the statistical properties of
the returns are different.


title: A Haar-like Construction for the Ornstein Uhlenbeck Process

abstract:
  The classical Haar construction of Brownian motion uses a binary tree of
triangular wedge-shaped functions. This basis has compactness properties which
make it especially suited for certain classes of numerical algorithms. We
present a similar basis for the Ornstein-Uhlenbeck process, in which the basis
elements approach asymptotically the Haar functions as the index increases, and
preserve the following properties of the Haar basis: all basis elements have
compact support on an open interval with dyadic rational endpoints; these
intervals are nested and become smaller for larger indices of the basis
element, and for any dyadic rational, only a finite number of basis elements is
nonzero at that number. Thus the expansion in our basis, when evaluated at a
dyadic rational, terminates in a finite number of steps. We prove the
covariance formulae for our expansion and discuss its statistical
interpretation and connections to asymptotic scale invariance.