title: Solution of Maxwell's equations on a de Sitter background

abstract:
  The Maxwell equations for the electromagnetic potential, supplemented by the
Lorenz gauge condition, are decoupled and solved exactly in de Sitter
space-time studied in static spherical coordinates. There is no source besides
the background. One component of the vector field is expressed, in its radial
part, through the solution of a fourth-order ordinary differential equation
obeying given initial conditions. The other components of the vector field are
then found by acting with lower-order differential operators on the solution of
the fourth-order equation (while the transverse part is decoupled and solved
exactly from the beginning). The whole four-vector potential is eventually
expressed through hypergeometric functions and spherical harmonics. Its radial
part is plotted for given choices of initial conditions. We have thus
completely succeeded in solving the homogeneous vector wave equation for
Maxwell theory in the Lorenz gauge when a de Sitter spacetime is considered,
which is relevant both for inflationary cosmology and gravitational wave
theory. The decoupling technique and analytic formulae and plots are completely
original. This is an important step towards solving exactly the tensor wave
equation in de Sitter space-time, which has important applications to the
theory of gravitational waves about curved backgrounds.


title:
Disk reflection signatures in the spectrum of the bright Z-source GX
  340+0

abstract:
  We present the preliminary results of a 50 ks long XMM-Newton observation of
the bright Z-source GX 340+0. In this Letter we focus on the study of a broad
asymmetric emission line in the Fe K alpha energy band, whose shape is clearly
resolved and compatible with a relativistically smeared profile arising from
reflection on a hot accretion disk extending close to the central accreting
neutron star. By combining temporal and spectral analysis, we are able to
follow the evolution of the source along its Horizontal Branch. However,
despite a significant change in the continuum emission and luminosity, the line
profile does not show any strong correlated variation. This broad line is
produced by recombination of highly ionized iron (Fe XXV) at an inferred inner
radius close to 13 gravitational radii while the fit requires a high value for
the outer disk radius. The inclination of the source is extremely well
constrained at 35 deg, while the emissivity index is -2.50.


title: Holographic flavor in N=4 gauge theories in 3d from wrapped branes

abstract:
  We study the addition of flavor to the gravity dual of N=4 three-dimensional
gauge theories obtained by wrapping $N_c$ D4-branes on a two-cycle of a
non-compact Calabi-Yau two-fold. In this setup the flavor is introduced by
adding another set of D4-branes that are extended along the non-compact
directions of the Calabi-Yau which are normal to the cycle which the color
branes wrap. The analysis is performed both in the quenched and unquenched
approximations. In this latter case we compute the backreacted metric and we
show that it reproduces the running of the gauge coupling. The meson spectrum
and the behavior of Wilson loops are also discussed and the holographic
realization of the Higgs branch is analyzed. Other aspects of this system
studied are the entanglement entropy and the non-relativistic version of our
backgrounds.


title: High fidelity entanglement of 43Ca+ hyperfine clock states

abstract:
  In an experiment using the odd calcium isotope 43Ca+ we combine the merits of
a high fidelity entangling operation on an optical transition (optical qubit)
with the long coherence times of two 'clock' states in the hyperfine ground
state (hyperfine qubit) by mapping between these two qubits. For state
initialization, state detection, global qubit rotations and mapping operations,
errors smaller than 1% are achieved whereas the entangling gate adds errors of
2.3%. Based on these operations, we create Bell states with a fidelity of
96.9(3)% in the optical qubit and a fidelity of 96.7(3)% when mapped to the
hyperfine states. In the latter case, the entanglement is preserved for 96(3)
ms, exceeding the duration of a single gate operation by three orders of
magnitude.


title: Kinetic quantum phase transition in bosonic superfluids on a lattice

abstract:
  It has been well known that quantum fluctuations induce a macroscopic phase
transition from a superfluid to a Mott insulator phase driven by the repulsive
potential energy in the ground state of dense bosonic systems on a lattice. We
find a quantum phase transition from the homogeneous to an inhomogeneous
Bose-condensate strongly affected or sometimes driven by the kinetic energy
dispersion in dilute bosonic superfluids, which provides a clear identification
of the superfluid state.


title: A mechanical approach to mean field spin models

abstract:
  Inspired by the bridge pioneered by Guerra among statistical mechanics on
lattice and analytical mechanics on 1+1 continuous Euclidean space-time, we
built a self-consistent method to solve for the thermodynamics of mean-field
models defined on lattice, whose order parameters self average. We show the
whole procedure by analyzing in full details the simplest test case, namely the
Curie-Weiss model. Further we report some applications also to models whose
order parameters do not self-average, by using the Sherrington-Kirkpatrick spin
glass as a guide.


title: Essential Variables and Separable Sets in Universal Algebra

abstract:
  The study of essential and strongly essential variables in functions defined
on finite sets is a part of $k$-valued logic. We extend the main definitions
from functions to terms. This allows us to apply concepts and results of
Universal Algebra. On the basis of the concept of a separable set of variables
in a term we introduce a new notion of complexity of terms, algebras and
varieties and give examples.


title: Scalar-Tensor theories and current Cosmology

abstract:
  Scalar-tensor theories are studied in the context of cosmological evolution,
where the expansion history of the Universe is reconstructed. It is considered
quintessence/phantom models, where inflation and cosmic acceleration are
reproduced. Also, the non-minimally coupling regime between the scalar field
and the Ricci scalar is studied and cosmological solutions are obtained. The
Chamaleon mechanism is shown as a solution of the local gravity tests problems
presented in this kind of theories.


title: On Born-Infeld Gravity in Weitzenbock spacetime

abstract:
  Using the Teleparallel Equivalent of General Relativity formulated in
Weitzenb\"{o}ck spacetime, we thoroughly explore a kind of Born-Infeld regular
gravity leading to second order field equations for the vielbein components. We
explicitly solve the equations of motion for two examples: the extended BTZ
black hole, which results to exist even if the cosmological constant is
positive, and a cosmological model with matter, where the scale factor results
to be well behaved, giving so a singularity-free solution.


title: Vector Supersymmetry: Casimir operators and contraction from OSp(3,2|2)

abstract:
  We study some algebraic properties of the 'vector supersymmetry' (VSUSY)
algebra, a graded extension of the four-dimensional Poincare' algebra with two
odd generators, a vector and a scalar, and two central charges. The
anticommutator between the two odd generators gives the four-momentum operator,
from which the name vector supersymmetry. We construct the Casimir operators
for this algebra and we show how both algebra and Casimirs can be derived by
contraction from the simple orthosymplectic algebra OSp(3,2|2). In particular,
we construct the analogue of superspin for vector supersymmetry and we show
that, due to the algebraic structure of the Casimirs, the multiplets are either
doublets of spin (s,s+1) or two spin 1/2 states. Finally, we identify an odd
operator, which is an invariant in a subclass of representations where a
BPS-like algebraic relation between the mass and the values of the central
charges is satisfied.


title:
\'Equations aux q-diff\'erences lin\'eaires: factorisation, r\'esolution
  et th\'eor\`emes d'indices

abstract:
  We describe explicit algorithms for factoring q-difference operators and
solving q-difference equations. These are well known results, presented in a
"concrete" form.
  -----
  Nous decrivons des algorithmes explicites pour la factorisation d'operateurs
et la resolution d'equations aux q-differences. Il s'agit d'une presentation
"concrete" de resultats bien connus.


title: Potential-density pairs for a family of finite disks

abstract:
  Exact analytical solutions are given for the three finite disks with surface
density $\Sigma_n=\sigma_0 (1-R^2/\alpha^2)^{n-1/2} \textrm{with} n=0, 1, 2$.
Closed-form solutions in cylindrical co-ordinates are given using only
elementary functions for the potential and for the gravitational field of each
of the disks.
  The n=0 disk is the flattened homeoid for which $\Sigma_{hom} =
\sigma_0/\sqrt{1-R^2/\alpha^2}$. Improved results are presented for this disk.
The n=1 disk is the Maclaurin disk for which $\Sigma_{Mac} = \sigma_0
\sqrt{1-R^2/\alpha^2}$. The Maclaurin disk is a limiting case of the Maclaurin
spheroid. The potential of the Maclaurin disk is found here by integrating the
potential of the n=0 disk over $\alpha$, exploiting the linearity of Poisson's
equation. The n=2 disk has the surface density $\Sigma_{D2}=\sigma_0
(1-R^2/\alpha^2)^{3/2}$. The potential is found by integrating the potential of
the n=1 disk.


title:
The Quantum No-Stretching: A geometrical interpretation of the
  no-cloning theorem

abstract:
  We consider the ideal situation in which a space rotation is transferred from
a quantum spin j to a quantum spin l different from j. Quantum-information
theoretical considerations lead to the conclusion that such operation is
possible only for lj. For l>j the optimal stretching transformation is derived.
We show that for qubits the present no-stretching theorem is equivalent to the
usual no-cloning theorem.


title: Control software analysis, part II: Closed-loop analysis

abstract:
  The analysis and proper documentation of the properties of closed-loop
control software presents many distinct aspects from the analysis of the same
software running open-loop. Issues of physical system representations arise,
and it is desired that such representations remain independent from the
representations of the control program. For that purpose, a concurrent program
representation of the plant and the control processes is proposed, although the
closed-loop system is sufficiently serialized to enable a sequential analysis.
While dealing with closed-loop system properties, it is also shown by means of
examples how special treatment of nonlinearities extends from the analysis of
control specifications to code analysis.


title: Quantum phase transition in Bose-Holstein model in two dimensions

abstract:
  We derive an effective d-dimensional Hamiltonian for a system of
hard-core-bosons coupled to optical phonons in a lattice. Away from
half-filling, we show that the presence of next-nearest-neighbor hopping in the
effective Hamiltonian leads to a superfluid-to-supersolid transition at
intermediate boson-phonon (b-p) couplings, while at strong-couplings the system
phase separates. However, at half-filling and at a critical b-p coupling (as in
the xxz-model), the system undergoes a superfluid-to-charge-density-wave
transition without any signature of supersolidity. Our analyses is based on
extensive calculations of the structure factor, the superfluid fraction, the
Bose-Einstein condensate fraction, and the system energy at various fillings.
We present a phase diagram for this system and compare it to that of the
xxz-model. We also demonstrate explicitly that the next-nearest-neighbor
hopping (in the absence of nearest-neighbor hopping) in the effective
Hamiltonian leads only to a single transition, i.e., a first-order
superfluid-to-supersolid transition.


title:
Study of the Hall effect in two different strongly correlated fermion
  systems

abstract:
  We investigate the Hall effect in two different theoretical models of
strongly correlated systems: a system made of weakly coupled Luttinger liquids,
in the presence of umklapp scattering, and the 2D triangular lattice, with
nearest-neighbor hopping and a local Hubbard interaction. In the first model we
use a memory function approach to compute the Hall coefficient as a function of
temperature and frequency in the presence of umklapp scattering. We find a
power-law correction to the free-fermion value (band value), with an exponent
depending on the Luttinger parameter $K_{\rho}$. At sufficiently high
temperature or frequency the Hall coefficient approaches the band value. We
discuss the applications to Hall experiments made in quasi 1D organic
compounds. In the second model, the complete temperature and doping
dependencies of the high-frequency Hall coefficient $\RH$ are evaluated
analytically and numerically for small, intermediate, and strong interactions
using various approximation schemes. We find that $\RH$ follows the
semiclassical $1/qn^*$ law near T=0, but exhibits a striking $T$-linear
behavior with an interaction- and doping-dependent slope at high temperature.
We compare our results with Hall measurements performed in cobaltates.


title: Slavnov-Taylor identities in Coulomb gauge Yang-Mills theory

abstract:
  The Slavnov-Taylor identities of Coulomb gauge Yang-Mills theory are derived
from the (standard, second order) functional formalism. It is shown how these
identities form closed sets from which one can in principle fully determine the
Green's functions involving the temporal component of the gauge field without
approximation, given appropriate input.


title:
Casimir Effect for Massless Fermions in One Dimension: A Force Operator
  Approach

abstract:
  We calculate the Casimir interaction between two short range scatterers
embedded in a background of one dimensional massless Dirac fermions using a
force operator approach. We obtain the force between two finite width square
barriers, and take the limit of zero width and infinite potential strength to
study the Casimir force mediated by the fermions. For the case of identical
scatterers we recover the conventional attractive one dimensional Casimir
force. For the general problem with inequivalent scatterers we find that the
magnitude and sign of this force depend on the relative spinor polarizations of
the two scattering potentials which can be tuned to give an attractive, a
repulsive, or a compensated null Casimir interaction.


title: A finite electroweak model without a Higgs particle

abstract:
  An electroweak model in which the masses of the W and Z bosons and the
fermions are generated by quantum loop graphs through a symmetry breaking is
investigated. The model is based on a regularized quantum field theory in which
the quantum loop graphs are finite to all orders of perturbation theory and the
massless theory is gauge invariant, Poincare invariant, and unitary. The
breaking of the electroweak symmetry SU_L(2) X U_Y(1) is achieved without a
Higgs particle. A fundamental energy scale \Lambda_W (not to be confused with a
naive cutoff) enters the theory through the regularization of the Feynman loop
diagrams. The finite regularized theory with \Lambda_W allows for a fitting of
low energy electroweak data. \Lambda_W ~ 542 GeV is determined at the Z pole by
fitting it to the Z mass m_Z, and anchoring the value of \sin^2\theta_w to its
experimental value at the Z pole yields a prediction for the W mass m_W that is
accurate to about 0.5% without radiative corrections. The scattering amplitudes
for W_LW_L -> W_LW_L and e+e- -> W_L^+W_L^- processes do not violate unitarity
at high energies due to the suppression of the amplitudes by the running of the
coupling constants at vertices. There is no Higgs hierarchy fine-tuning problem
in the model. The unitary tree level amplitudes for W_LW_L -> W_LW_L scattering
and e+e- -> W_L^+W_L^- annihilation, predicted by the finite electroweak model
are compared with the amplitudes obtained from the standard model with Higgs
exchange. These predicted amplitudes can be used to distinguish at the LHC
between the standard electroweak model and the Higgsless model.


title: Some Integrals of the Dedekind Eta-function

abstract:
  This note presents selected values of definite integrals whose integrand
contains a power of the Dedekind function having imaginary argument.


title:
On the normal holonomy representation of spacelike submanifolds in
  pseudo-Riemannian space forms

abstract:
  In this paper we study weakly irreducible holonomy representations of the
normal connection of a spacelike submanifold in a pseudo-Riemannian space from.
We associate screen representations to weakly irreducible normal holonomy
groups and classify the screen representations having the Borel-Lichn\'erowicz
property. In particular, we derive a classification of Lorentzian normal
holonomy representations.


title:
The running of coupling constants and unitarity in a finite electroweak
  model

abstract:
  We investigate the properties of a Finite Electroweak (FEW) Theory first
proposed in 1991. The theory predicts a running of the electroweak coupling
constants and a suppression of tree level amplitudes, ensuring unitarity
without a Higgs particle. We demonstrate this explicitly by calculating
W_L^+W_L^- -> W_L^+W_L^- and e+e- -> W_L^+W_L^- in both the electroweak
Standard Model and the FEW model.


title:
A route to quasi-perfect invisibility cylindrical cloaks without extreme
  values in the parameters

abstract:
  The method of coordinate transformation offers a way to realize perfect
cloaks, but provides less ability to characterize the performance of a
multilayered cloak in practice. Here, we propose an analytical model to predict
the performance of a multilayered cylindrical cloak, based on which, the cloak
in practice can be optimized to diminish the intrinsic scatterings caused by
discretization and simplification. Extremely low scattering or "quasi-perfect
invisibility" can be achieved with only a few layers of anisotropic
metamaterials without following the transformation method. Meanwhile, the
permittivity and permeability parameters of the layers are relatively small,
which is a remarkable advantage of our approach.


title: Relativistic Brownian Motion

abstract:
  Stimulated by experimental progress in high energy physics and astrophysics,
the unification of relativistic and stochastic concepts has re-attracted
considerable interest during the past decade. Focusing on the framework of
special relativity, we review, here, recent progress in the phenomenological
description of relativistic diffusion processes. After a brief historical
overview, we will summarize basic concepts from the Langevin theory of
nonrelativistic Brownian motions and discuss relevant aspects of relativistic
equilibrium thermostatistics. The introductory parts are followed by a detailed
discussion of relativistic Langevin equations in phase space. We address the
choice of time parameters, discretization rules, relativistic
fluctuation-dissipation theorems, and Lorentz transformations of stochastic
differential equations. The general theory is illustrated through analytical
and numerical results for the diffusion of free relativistic Brownian
particles. Subsequently, we discuss how Langevin-type equations can be obtained
as approximations to microscopic models. The final part of the article is
dedicated to relativistic diffusion processes in Minkowski spacetime. Due to
the finiteness of velocities in relativity, nontrivial relativistic Markov
processes in spacetime do not exist; i.e., relativistic generalizations of the
nonrelativistic diffusion equation and its Gaussian solutions must necessarily
be non-Markovian. We compare different proposals that were made in the
literature and discuss their respective benefits and drawbacks. The review
concludes with a summary of open questions, which may serve as a starting point
for future investigations and extensions of the theory.


title: Exploring dynamic localization with a Bose-Einstein condensate

abstract:
  We report on the experimental observation of dynamic localization of a
Bose-Einstein condensate in a shaken optical lattice, both for sinusoidal and
square-wave forcing. The formulation of this effect in terms of a quasienergy
band collapse, backed by the excellent agreement of the observed collapse
points with the theoretical predictions, suggests the feasibility of systematic
quasienergy band engineering.


title: Improved parameters for the transiting hot Jupiters WASP-4b and WASP-5b

abstract:
  The gaseous giant planets WASP-4b and WASP-5b are transiting 12 magnitude
solar-type stars in the Southern hemisphere. The aim of the present work is to
refine the parameters of these systems using high cadence VLT/FORS2 z-band
transit photometry and high resolution VLT/UVES spectroscopy. For WASP-4, the
new estimates for the planet radius and mass from a combined analysis of our
VLT data with previously published transit photometry and radial velocities are
R_p = 1.30 +0.05-0.04 R_jup and M_p = 1.21 +0.13-0.08 M_jup, resulting in a
density rho_p = 0.55 +0.04-0.02 rho_jup. The radius and mass for the host star
are R_s = 0.87 +0.04-0.03 R_sun and M_s = 0.85 +0.11-0.07 M_sun. Our
ground-based photometry reaches 550 ppm at time sampling of ~50 seconds.
Nevertheless, we also report the presence of an instrumental effect on the VLT
that degraded our photometry for the WASP-5 observations. This effect could be
a major problem for similar programs. Our new estimates for the parameters of
the WASP-5 system are R_p = 1.09 +-0.07 R_jup, M_p = 1.58 +0.13-0.10 M_jup,
rho_p = 1.23 +0.26-0.16 rho_jup, R_s = 1.03 +0.06-0.07 R_sun, and M_s = 0.96
+0.13-0.09 M_sun. The measured size of WASP-5b agrees well with the basic
models of irradiated planets, while WASP-4b is clearly an `anomalously' large
planet.


title:
Measurement of the Slope Parameter $\alpha$ for the $\eta\to 3\pi^0$
  decay with the Crystal Ball detector at the Mainz Microtron (MAMI-C)

abstract:
  The dynamics of the $\eta\to 3\pi^0$ decay have been studied with the Crystal
Ball multiphoton spectrometer and the TAPS calorimeter. Bremsstrahlung photons
produced by the 1.5-GeV electron beam of the Mainz microtron MAMI-C and tagged
by the Glasgow photon spectrometer were used for $\eta$-meson production. The
analysis of $3 \times 10^6$ $\gamma p \to \eta p \to 3\pi^0 p \to 6\gamma p$
events yields the value $\alpha=-0.032\pm0.003$ for the $\eta\to 3\pi^0$ slope
parameter, which agrees with the majority of recent experimental results and
has the smallest uncertainty. The $\pi^0\pi^0$ invariant-mass spectrum was
investigated for the occurrence of a cusplike structure in the vicinity of the
$\pi^+\pi^-$ threshold. The observed effect is small and does not affect our
measured value for the slope parameter.


title: Correlated Random Walks and the Joint Survival Probability

abstract:
  First passage models, where corporate assets undergo correlated random walks
and a company defaults if its assets fall below a threshold provide an
attractive framework for modeling the default process. Typical one year default
correlations are small, i.e., of order a few percent, but nonetheless including
correlations is very important, for managing portfolio credit risk and pricing
some credit derivatives (e.g. first to default baskets). In first passage
models the exact dependence of the joint survival probability of more than two
firms on their asset correlations is not known. We derive an expression for the
dependence of the joint survival probability of $n$ firms on their asset
correlations using first order perturbation theory in the correlations. It
includes all terms that are linear in the correlations but neglects effects of
quadratic and higher order. For constant time independent correlations we
compare the first passage model expression for the joint survival probability
with what a multivariate normal Copula function gives. As a practical
application of our results we calculate the dependence of the five year joint
survival probability for five basic industrials on their asset correlations.


title: Inner and outer edge states in graphene rings: A numerical investigation

abstract:
  We numerically investigate quantum rings in graphene and find that their
electronic properties may be strongly influenced by the geometry, the edge
symmetries and the structure of the corners. Energy spectra are calculated for
different geometries (triangular, hexagonal and rhombus-shaped graphene rings)
and edge terminations (zigzag, armchair, as well as the disordered edge of a
round geometry). The states localized at the inner edges of the graphene rings
describe different evolution as a function of magnetic field when compared to
those localized at the outer edges. We show that these different evolutions are
the reason for the formation of sub-bands of edge states energy levels,
separated by gaps (anticrossings). It is evident from mapping the charge
densities that the anticrossings occur due to the coupling between inner and
outer edge states.


title:
The Pervasive Role of the Nuclear Symmetry Energy in the Structure and
  Evolution of Neutron Stars

abstract:
  The multifaceted role of the density dependent nuclear symmetry energy in the
nuclear astrophysics involving neutron stars is highlighted. Efforts toward a
model independent determination of the dense matter equation state through a
deconstruction of the neutron star structure equation utilizing the masses and
radii of several individual neutron stars are described. The need for
observational data of both measurements for the same star is stressed.


title:
Deep inelastic scattering with leading protons or large rapidity gaps at
  HERA

abstract:
  The dissociation of virtual photons, $\gamma^{\star} p \to X p$, in events
with a large rapidity gap between $X$ and the outgoing proton, as well as in
events in which the leading proton was directly measured, has been studied with
the ZEUS detector at HERA. The data cover photon virtualities $Q^2>2$ GeV$^2$
and $\gamma^{\star} p$ centre-of-mass energies $40<W<240$ GeV, with $M_X>2$
GeV, where $M_X$ is the mass of the hadronic final state, $X$. Leading protons
were detected in the ZEUS leading proton spectrometer. The cross section is
presented as a function of $t$, the squared four-momentum transfer at the
proton vertex and $\Phi$, the azimuthal angle between the positron scattering
plane and the proton scattering plane. It is also shown as a function of $Q^2$
and $\xpom$, the fraction of the proton's momentum carried by the diffractive
exchange, as well as $\beta$, the Bjorken variable defined with respect to the
diffractive exchange.


title: Geometric transition in friction for flow over a bubble mattress

abstract:
  Laminar flow over a bubble mattress is expected to experience a significant
reduction in friction since the individual surfaces of the bubbles are
shear-free. However, if the bubbles are sufficiently curved, their protrusion
into the fluid and along the flow direction can lead to an increase in friction
as was recently demonstrated experimentally and computationally. We provide in
this paper a simple model for this result. We consider a shear flow at low
Reynolds number past a two-dimensional array of bubbles, and calculate
analytically the effective slip length of the surface as function of the bubble
geometry in the dilute limit. Our model is able to reproduce quantitatively the
relationship between effective friction and bubble geometry obtained in
numerical computations, and in particular: (a) The asymmetry in friction
between convex and concave bubbles, and (b) the existence of a geometric
transition from reduced to enhanced friction at a critical bubble protrusion
angle.


title:
The ADHM construction and non-local symmetries of the self-dual
  Yang-Mills equations

abstract:
  We consider the action on instanton moduli spaces of the non-local symmetries
of the self-dual Yang-Mills equations on $\mathbb{R}^4$ discovered by Chau and
coauthors. Beginning with the ADHM construction, we show that a sub-algebra of
the symmetry algebra generates the tangent space to the instanton moduli space
at each point. We explicitly find the subgroup of the symmetry group that
preserves the one-instanton moduli space. This action simply corresponds to a
scaling of the moduli space.


title: Whence the odd-even staggering in nuclear binding?

abstract:
  We explore the systematics of odd-even mass staggering with a view to
identifying the physical mechanisms responsible. The BCS pairing and mean field
contributions have A- and number parity dependencies which can help disentangle
the different contributions. This motivates the two-term parametrization c_1 +
c_2/A as a theoretically based alternative to the inverse power form
traditionally used to fit odd-even mass differences. Assuming that the
A-dependence of the BCS pairing is weak, we find that mean-field contributions
are dominant below mass number A~40 while BCS pairing dominates in heavier
nuclei.


title:
Absolute Magnitude Distribution And Light Curves Of Gamma-Ray Burst
  Supernovae

abstract:
  Photometry data were collected from the literature and analyzed for
supernovae that are thought to have a gamma-ray burst association. There are
several gamma-ray burst afterglow light curves that appear to have a supernova
component. For these light curves, the supernova component was extracted and
analyzed. A supernova light curve model was used to help determine the peak
absolute magnitudes as well as estimates for the kinetic energy, ejected mass
and nickel mass in the explosion. The peak absolute magnitudes are, on average,
brighter than those of similar supernovae (stripped-envelope supernovae) that
do not have a gamma-ray burst association, but this can easily be due to a
selection effect. However, the kinetic energies and ejected masses were found
to be considerably higher, on average, than those of similar supernovae without
a gamma-ray burst association.


title: Correlated Counting of Single Electrons in a Nanowire Double Quantum Dot

abstract:
  We report on correlated real-time detection of individual electrons in an
InAs nanowire double quantum dot. Two self-aligned quantum point contacts in an
underlying two-dimensional electron gas material serve as highly sensitive
charge detectors for the double quantum dot. Tunnel processes of individual
electrons and all tunnel rates are determined by simultaneous measurements of
the correlated signals of the quantum point contacts.


title: Topological Modular Forms of Level 3

abstract:
  We describe and compute the homotopy of spectra of topological modular forms
of level 3. We give some computations related to the "building complex"
associated to level 3 structures at the prime 2. Finally, we note the existence
of a number of connective models of the spectrum TMF(Gamma_0(3)).


title: Goldie Ranks of Skew Power Series Rings of Automorphic Type

abstract:
  Let A be a semprime, right noetherian ring equipped with an automorphism
alpha, and let B := A[[y; alpha]] denote the corresponding skew power series
ring (which is also semiprime and right noetherian). We prove that the Goldie
ranks of A and B are equal. We also record applications to induced ideals.


title: Accelerated Data-Flow Analysis

abstract:
  Acceleration in symbolic verification consists in computing the exact effect
of some control-flow loops in order to speed up the iterative fix-point
computation of reachable states. Even if no termination guarantee is provided
in theory, successful results were obtained in practice by different tools
implementing this framework. In this paper, the acceleration framework is
extended to data-flow analysis. Compared to a classical
widening/narrowing-based abstract interpretation, the loss of precision is
controlled here by the choice of the abstract domain and does not depend on the
way the abstract value is computed. Our approach is geared towards precision,
but we don't loose efficiency on the way. Indeed, we provide a cubic-time
acceleration-based algorithm for solving interval constraints with full
multiplication.


title:
The Spitzer c2d Survey of Nearby Dense Cores. V. Discovery of a VeLLO in
  the "Starless" Dense Core L328

abstract:
  This paper reports the discovery of a Very Low Luminosity Object (VeLLO) in
the "starless" dense core L328, using the Spitzer Space Telescope and ground
based observations from near-infrared to millimeter wavelengths. The Spitzer 8
micron image indicates that L328 consists of three subcores of which the
smallest one may harbor a source, L328-IRS while two other subcores remain
starless. L328-IRS is a Class 0 protostar according to its bolometric
temperature (44 K) and the high fraction ~72 % of its luminosity emitted at
sub-millimeter wavelengths. Its inferred "internal luminosity" (0.04 - 0.06
Lsun) using a radiative transfer model under the most plausible assumption of
its distance as 200 pc is much fainter than for a typical protostar, and even
fainter than other VeLLOs studied previously. Note, however, that its inferred
luminosity may be uncertain by a factor of 2-3 if we consider two extreme
values of the distance of L328-IRS (125 or 310 pc). Low angular resolution
observations of CO do not show any clear evidence of a molecular outflow
activity. But broad line widths toward L328, and Spitzer and near-infrared
images showing nebulosity possibly tracing an outflow cavity, strongly suggest
the existence of outflow activity. Provided that an envelope of at most ~0.1
Msunis the only mass accretion reservoir for L328-IRS, and the star formation
efficiency is close to the canonical value ~30%, L328-IRS has not yet accreted
more than 0.05 Msun. At the assumed distance of 200 pc, L328-IRS is destined to
be a brown dwarf.


title: Periodic Variables in the Open Cluster NGC 2301

abstract:
  We present the results of a search for periodic variables within 4078
time-series light curves and an analysis of the period-color plane for stars in
the field of the open cluster NGC2301. One hundred thirty-eight periodic
variables were discovered, of which five are eclipsing binary candidates with
unequal minima. The remaining 133 periodic variables appear to consist mainly
of late-type stars whose variation is due to rotation modulated by star spot
activity. The determined periods range from less than a day to over 14 days and
have nearly unreddened B-R colors in the range of 0.8 to 2.8. The Barnes (2003)
interpretation of the period-color plane of late type stars is tested with our
data. Our data did not show distinct I and C sequences, likely due to nonmember
field stars contaminating in the background, as we estimate the total
contamination to be 43%. Using different assumptions, the gyrochronological age
of the cluster is calculated to be 210+/-25 Myr, which falls in the range of
age values (164-250 Myr) determined by previous studies. Finally, we present
evidence which nullifies the earlier suggestion that two of the variable stars
in NGC2301 might be white dwarfs.


title: Convex Hull of Arithmetic Automata

abstract:
  Arithmetic automata recognize infinite words of digits denoting
decompositions of real and integer vectors. These automata are known expressive
and efficient enough to represent the whole set of solutions of complex linear
constraints combining both integral and real variables. In this paper, the
closed convex hull of arithmetic automata is proved rational polyhedral.
Moreover an algorithm computing the linear constraints defining these convex
set is provided. Such an algorithm is useful for effectively extracting
geometrical properties of the whole set of solutions of complex constraints
symbolically represented by arithmetic automata.


title:
The 21 micron and 30 micron circumstellar dust features in evolved
  C-rich objects

abstract:
  The 21micron and 30micron bands are the strongest dust emission features
detected in evolved low- and intermediate-mass C-rich stars (i.e. asymptotic
giant branch [AGB] stars, proto-planetary nebulae [PPN], and planetary nebulae
[PN]). While the 21micron feature is rare and exists only in the transient PPN
phase, the 30micron feature is more common and seen in the entire late stage of
stellar evolution, from AGB to PPN and PN phases, as well as in the
low-metallicity galaxies: the Large Magellanic Cloud (LMC) and the Small
Magellanic Cloud (SMC). The carriers of these features remain unidentified.
Eleven of the twelve well-identified 21micron sources also emit in the 30micron
band, suggesting that their carriers may be somewhat related.


title:
Toward understanding the 3.4 micron and 9.7 micron extinction feature
  variations from the local diffuse interstellar medium to the Galactic center

abstract:
  Observationally, both the 3.4micron aliphatic hydrocarbon C--H stretching
absorption feature and the 9.7micron amorphous silicate Si--O stretching
absorption feature show considerable variations from the local diffuse
interstellar medium (ISM) to Galactic center (GC): both the ratio of the visual
extinction (A_V) to the 9.7micron Si--O optical depth (\tausil) and the ratio
of A_V to the 3.4micron C--H optical depth (\tauahc) of the solar neighborhood
local diffuse ISM are about twice as much as that of the GC. In this work, we
try to explain these variations in terms of a porous dust model consisting of a
mixture of amorphous silicate, carbonaceous organic refractory dust (as well as
water ice for the GC dust).


title: Cubic ergodic averages for actions of amenable groups

abstract:
  We unify and extend some previous results about cubic ergodic averages and
sets of positive density in products of groups. This provides a joint
generalization of earlier work of the author in the case of two commuting
actions of an amenable group, and of Q. Chu's recent result on a a finite
number of commuting transformations.


title: Essential observations of the Lyman continuum

abstract:
  Concurrent observations of Lyman continuum (LyC) and Lyman-alpha (Lya)
emission escaping from star-forming systems at low redshift are essential to
understanding the physics of reionization at high redshift (z >~ 6). Some have
suggested reionization is dominated by numerous small galaxies with LyC escape
fractions f_e ~ 10%, while others suggest mini-quasars with higher f_e might
also play a role. At z > 3, direct observation of LyC leakage becomes
progressively more improbable due to the increase of intervening Ly limit
systems, leaving Lya as the primary diagnostic available to the James Webb
Space Telescope for exploring the epoch of reionization. If a quantitative
relationship between escaping LyC and Lya emission can be established at low z,
then the diagnostic power of Lya as a LyC proxy at high z can be fully
realized. Past efforts to detect f_e near z ~ 3 have been fruitful but
observations at low redshift have been less so. We discuss the sensitivity
requirements for detecting LyC leak in the far- and near-UV as a function of
redshift 0.02 < z ~< 3 and f_e >= 0.01 as estimated from UV luminosity
functions. UV observations are essential to understanding of the physics of LyC
escape and the ultimate goal of identifying the source(s) responsible for
reionization.


title:
Model of Reconnection of Weakly Stochastic Magnetic Field and its
  Implications

abstract:
  We discuss the model of magnetic field reconnection in the presence of
turbulence introduced by us approximately ten years ago. The model does not
require any plasma effects to be involved in order to make the reconnection
fast. In fact, it shows that the degree of magnetic field stochasticity
controls the reconnection. The turbulence in the model is assumed to be
subAlfvenic, with the magnetic field only slightly perturbed. This ensures that
the reconnection happens in generic astrophysical environments and the model
does not appeal to any unphysical concepts, similar to the turbulent magnetic
diffusivity concept, which is employed in the kinematic magnetic dynamo. The
interest to that model has recently increased due to successful numerical
testings of the model predictions. In view of this, we discuss implications of
the model, including the first-order Fermi acceleration of cosmic rays, that
the model naturally entails, bursts of reconnection, that can be associated
with Solar flares, as well as, removal of magnetic flux during star-formation.


title: X-raying the Intergalactic OVI Absorbers

abstract:
  The observed intergalactic OVI absorbers at z>0 have been regarded as a
significant reservoir of the ``missing baryons''. However, to fully understand
how these absorbers contribute to the baryon inventory, it is crucial to
determine whether the systems are collisionally ionized or photoionized (or
both). Using the identified intergalactic OVI absorbers as tracers, we search
for the corresponding X-ray absorption lines, which are useful for finding the
missing baryons and for revealing the nature of the OVI absorbers. Stacking the
Chandra grating spectra along six AGN sight lines, we obtain three spectra with
signal-to-noise ratios of 32, 28, and 10 per 12.5 mA spectral bin around the
expected OVII Kalpha wavelength. These spectra correspond to OVI absorbers with
various dynamic properties. We find no detectable NeIX, OVII, OVIII, NVII, or
CVI absorption lines in the spectra, but the high counting statistics allows us
to obtain firm upper limits on the corresponding ionic column densities (in
particular N(OVII)<=10 N(OVI) on average at the 95% confidence level). Jointly
analyzing these non-detected X-ray lines with the averaged OVI column density,
we further limit the average temperature of the OVI-bearing gas to be
log[T(K)]<=5.7 in collisional ionization equilibrium. We discuss the
implications of these results for physical properties of the putative warm-hot
intergalactic medium and its detection in future X-ray observations.


title:
A Wide-Field Study of the z~0.8 Cluster RX J0152.7-1357: the Role of
  Environment in the Formation of the Red-Sequence

abstract:
  [ABRIDGED] We present the first results from the largest spectroscopic survey
to date of an intermediate redshift galaxy cluster, the z=0.834 cluster RX
J0152.7-1357. We use the colors of galaxies, assembled from a D~12 Mpc region
centered on the cluster, to investigate the properties of the red-sequence as a
function of density and clustercentric radius. Our wide-field multi-slit survey
with a low-dispersion prism in the IMACS spectrograph at Magellan allowed us to
identify 475 new members of the cluster and its surrounding large scale
structure with a redshift accuracy of dz/(1+z)~1% and a contamination rate of
~2% for galaxies with i<23.75 mag. We combine these new members with the 279
previously known spectroscopic members to give a total of 754 galaxies from
which we obtain a mass-limited sample of 300 galaxies with stellar masses
M>4x10^{10} M_sun. We find that the red galaxy fraction is 93+/-3% in the two
merging cores of the cluster and declines to a level of 64+/-3% at projected
clustercentric radii R>~3 Mpc. At these large projected distances, the
correlation between clustercentric radius and local density is nonexistent.
This allows an assessment of the influence of the local environment on galaxy
evolution, as opposed to mechanisms that operate on cluster scales. Even beyond
R>3 Mpc we find an increasing fraction of red galaxies with increasing local
density. The red fraction at the highest local densities in two groups at R>3
Mpc matches the red fraction found in the two cores. Strikingly, galaxies at
intermediate densities at R>3 Mpc, that are not group members, also show signs
of an enhanced red fraction. Our results point to such intermediate density
regions and the groups in the outskirts of the cluster, as sites where the
local environment influences the transition of galaxies onto the red-sequence.


title: WINGS-SPE Spectroscopy in the WIde-field Nearby Galaxy-cluster Survey

abstract:
  Aims. We present the results from a comprehensive spectroscopic survey of the
WINGS (WIde-field Nearby Galaxy-cluster Survey) clusters, a program called
WINGS-SPE. The WINGS-SPE sample consists of 48 clusters, 22 of which are in the
southern sky and 26 in the north. The main goals of this spectroscopic survey
are: (1) to study the dynamics and kinematics of the WINGS clusters and their
constituent galaxies, (2) to explore the link between the spectral properties
and the morphological evolution in different density environments and across a
wide range in cluster X-ray luminosities and optical properties. Methods. Using
multi object fiber fed spectrographs, we observed our sample of WINGS cluster
galaxies at an intermediate resolu- tion of 6-9 A and, using a
cross-correlation technique, we measured redshifts with a mean accuracy of
about 45 km/s. Results. We present redshift measurements for 6137 galaxies and
their first analyses. Details of the spectroscopic observations are reported.
The WINGS-SPE has about 30% overlap with previously published data sets,
allowing us to do both a complete comparison with the literature and to extend
the catalogs. Conclusions. Using our redshifts, we calculate the velocity
dispersion for all the clusters in the WINGS-SPE sample. We almost trip- licate
the number of member galaxies known in each cluster with respect to previous
works. We also investigate the X-ray luminosity vs. velocity dispersion
relation for our WINGS-SPE clusters, and find it to be consistent with the form
Lx proportional to sigma^4.


title:
Statistics of Galactic Synchrotron and Dust Foregrounds: Spectra, PDFs
  and Higher-Order Moments

abstract:
  We present statistical analysis of diffuse Galactic synchrotron emission and
polarized thermal emission from dust. Both Galactic synchrotron emission and
polarized thermal emission from dust reflect statistics of magnetic field
fluctuations and, therefore, Galactic turbulence. We mainly focus on the
relation between observed angular spectra and underlying turbulence statistics.
Our major findings are as follows. First, we find that magnetohydrodynamic
(MHD) turbulence in the Galaxy can indeed explain diffuse synchrotron emission
from high galactic latitude. Our model calculation suggests that either a
one-component extended halo model or a two-component model, an extended halo
component (scale height > 1kpc) plus a local component, can explain the
observed angular spectrum of the synchrotron emission. However, discrete
sources seem to dominate the spectrum for regions near the Galactic plane.
Second, we study how star-light polarization is related with polarized emission
from thermal dust. We also discuss the expected angular spectrum of polarized
emission from thermal dust. Our model calculations suggest that C_l\propto
l^{-11/3} for l > 1000 and a shallower spectrum for l < 1000.


title: Numerical Studies of Weakly Stochastic Magnetic Reconnection

abstract:
  We study the effects of turbulence on magnetic reconnection using
three-dimensional numerical simulations. This is the first attempt to test a
model of fast magnetic reconnection proposed by Lazarian & Vishniac (1999),
which assumes the presence of weak, small-scale magnetic field structure near
the current sheet. This affects the rate of reconnection by reducing the
transverse scale for reconnection flows and by allowing many independent flux
reconnection events to occur simultaneously. We performed a number of
simulations to test the dependencies of the reconnection speed, defined as the
ratio of the inflow velocity to the Alfven speed, on the turbulence power, the
injection scale and resistivity. Our results show that turbulence significantly
affects the topology of magnetic field near the diffusion region and increases
the thickness of the outflow region. We confirm the predictions of the Lazarian
& Vishniac model. In particular, we report the growth of the reconnection speed
proportional to ~ V^2, where V is the amplitude of velocity at the injection
scale. It depends on the injection scale l as ~ (l/L)^(2/3), where L is the
size of the system, which is somewhat faster but still roughly consistent with
the theoretical expectations. We also show that for 3D reconnection the Ohmic
resistivity is important in the local reconnection events only, and the global
reconnection rate in the presence of turbulence does not depend on it.


title:
Redistributing hot gas around galaxies: do cool clouds signal a solution
  to the overcooling problem?

abstract:
  We present a pair of high-resolution smoothed particle hydrodynamics (SPH)
simulations that explore the evolution and cooling behavior of hot gas around
Milky-Way size galaxies. The simulations contain the same total baryonic mass
and are identical other than their initial gas density distributions. The first
is initialised with a low entropy hot gas halo that traces the cuspy profile of
the dark matter, and the second is initialised with a high-entropy hot halo
with a cored density profile as might be expected in models with pre-heating
feedback. Galaxy formation proceeds in dramatically different fashion depending
on the initial setup. While the low-entropy halo cools rapidly, primarily from
the central region, the high-entropy halo is quasi-stable for ~4 Gyr and
eventually cools via the fragmentation and infall of clouds from ~100 kpc
distances. The low-entropy halo's X-ray surface brightness is ~100 times
brighter than current limits and the resultant disc galaxy contains more than
half of the system's baryons. The high-entropy halo has an X-ray brightness
that is in line with observations, an extended distribution of
pressure-confined clouds reminiscent of observed populations, and a final disc
galaxy that has half the mass and ~50% more specific angular momentum than the
disc formed in the low-entropy simulation. The final high-entropy system
retains the majority of its baryons in a low-density hot halo. The hot halo
harbours a trace population of cool, mostly ionised, pressure-confined clouds
that contain ~10% of the halo's baryons after 10 Gyr of cooling. The covering
fraction for HI and MgII absorption clouds in the high-entropy halo is ~0.4 and
~0.6, respectively, although most of the mass that fuels disc growth is
ionised, and hence would be under counted in HI surveys.


title: Codimension and pseudometric in co-Heyting algebras

abstract:
  In this paper we introduce a notion of dimension and codimension for every
element of a distributive bounded lattice $L$. These notions prove to have a
good behavior when $L$ is a co-Heyting algebra. In this case the codimension
gives rise to a pseudometric on $L$ which satisfies the ultrametric triangle
inequality. We prove that the Hausdorff completion of $L$ with respect to this
pseudometric is precisely the projective limit of all its finite dimensional
quotients. This completion has some familiar metric properties, such as the
convergence of every monotonic sequence in a compact subset. It coincides with
the profinite completion of $L$ if and only if it is compact or equivalently if
every finite dimensional quotient of $L$ is finite. In this case we say that
$L$ is precompact. If $L$ is precompact and Hausdorff, it inherits many of the
remarkable properties of its completion, specially those regarding the
join/meet irreducible elements. Since every finitely presented co-Heyting
algebra is precompact Hausdorff, all the results we prove on the algebraic
structure of the latter apply in particular to the former. As an application,
we obtain the existence for every positive integers $n,d$ of a term $t_{n,d}$
such that in every co-Heyting algebra generated by an $n$-tuple $a$,
$t_{n,d}(a)$ is precisely the maximal element of codimension $d$.


title:
On Bellissima's construction of the finitely generated free Heyting
  algebras, and beyond

abstract:
  We study finitely generated free Heyting algebras from a topological and from
a model theoretic point of view. We review Bellissima's representation of the
finitely generated free Heyting algebra; we prove that it yields an embedding
in the profinite completion, which is also the completion with respect to a
naturally defined metric. We give an algebraic interpretation of the Kripke
model used by Bellissima as the principal ideal sprectrum and show it to be
first order interpretable in the Heyting algebra, from which several model
theoretic and algebraic properties are derived. For example we prove that a
free finitely generated Heyting algebra has only one set of free generators,
which is definable in it. As a consequence its automorphism group is the
permutation group over its generators.


title: A characteristic signature of fourth order gravity

abstract:
  We present for the first time the complete matter power spectrum for $R^n$
gravity which has been derived from the fourth order scalar perturbation
equations. This leads to the discovery of a characteristic signature of fourth
order gravity in the matter power spectrum, the details of which have not seen
before in other studies in this area and therefore provides a crucial test for
fourth order gravity on cosmological scales.


title:
Exploring the Star Formation History of Elliptical Galaxies: Beyond
  Simple Stellar Populations with a New Estimator of Line Strengths

abstract:
  (Abridged) We study the stellar populations of 14 elliptical galaxies in the
Virgo cluster. We propose an alternative approach to the standard side-band
method to measure equivalent widths (EWs). Our Boosted Median Continuum maps
the EWs more robustly than the side-band method, minimising the effect from
neighbouring absorption lines and reducing the age-metallicity degeneracy. We
concentrate on Balmer lines (Hbeta,Hgamma,Hdelta), the G band and the 4000A
break as age-sensitive indicators, and on the combination [MgFe] as the main
metallicity indicator. We go beyond the standard comparison of the observations
with simple stellar populations (SSP) and consider various models to describe
the star formation histories, either with a continuous star formation rate or
with a mixture of two different SSPs. Composite models are found to give more
consistent fits among individual line strengths and agree with an independent
estimate using the spectral energy distribution. Our age and metallicity
estimates correlate well with stellar mass or velocity dispersion, with a
significant threshold around 5E10 Msun above which galaxies are uniformly old
and metal rich. In a more speculative way, our models suggest that it is
formation **epoch** and not formation timescale what drives the Mass-Age
relationship of elliptical galaxies.


title:
Non-Standard Physics in Leptonic and Semileptonic Decays of Charmed
  Mesons

abstract:
  Recent measurements of the branching fraction for D_s -> l nu disagree with
the Standard Model expectation, which relies on calculations of $f_{D_s}$ from
lattice QCD. This paper uses recent preliminary measurements from CLEO and a
new preliminary lattice-QCD result from this conference to update the
significance of the discrepancy. The "f_{D_s} puzzle" stands now at 3.5sigma,
with sigma predominantly from the statistical uncertainty of the experiments.
New physics scenarios that could solve the puzzle would also lead to
non-Standard amplitudes mediating the semileptonic decays D -> K l nu. This
paper shows where the new amplitudes enter the differential rate and outlines
where lattice QCD calculations are needed to confront recent and forthcoming
measurements.


title: Oscillations of the Inner Regions of Viscous Accretion Disks

abstract:
  Although quasi-periodic oscillations (QPOs) have been discovered in different
X-ray sources, their origin is still a matter of debate. Analytical studies of
hydrodynamic accretion disks have shown three types of trapped global modes
with properties that appear to agree with the observations. However, these
studies take only linear effects into account and do not address the issues of
mode excitation and decay. Moreover, observations suggest that resonances
between modes play a crucial role. A systematic, numerical study of this
problem is therefore needed. In this paper, we use a pseudo-spectral algorithm
to perform a parameter study of the inner regions of hydrodynamic disks. By
assuming alpha-viscosity, we show that steady state solutions rarely exist. The
inner edges of the disks oscillate and excite axisymmetric waves. In addition,
the flows inside the inner edges are sometimes unstable to non-axisymmetric
perturbations. One-armed, or even two-armed, spirals are developed, which
provides a plausible explanation for the high-frequency QPOs observed from
accreting black holes. When the Reynolds numbers are above certain critical
values, the inner disks go through some transient turbulent states
characterized by strong trailing spirals; while large-scale leading spirals
developed in the outer disks. We compared our numerical results with standard
thin disk oscillation models. Although the non-axisymmetric features have their
analytical counterparts, more careful study is needed to explain the
axisymmetric oscillations.


title:
Spatial Resolution Enhancement in Quantum Imaging beyond the Diffraction
  Limit Using Entangled Photon-Number State

abstract:
  In this paper we study the resolution of images illuminated by sources
composed of $N+1$ photons in which one non-degenerate photon is entangled with
$N$ degenerate photons. The $N$ degenerate photons illuminate an object and are
collected by an $N$ photon detector. The signal from the $N$ photon detector is
measured in coincidence with the non-degenerate photon giving rise to a ghost
image. We discuss the case of three photons in various configurations and
generalize to $N+1$. Using the Rayleigh criterion, we find that the system may
give an improvement in resolution by a factor of $N$ compared to using a
classical source. For the case that the $N$-photon number detector is a point
detector, a coherent image is obtained. If the $N$-photon detector is a bucket
detector, the image is incoherent. The visibility of the image in both cases is
1. In the opposite case in which the non-degenerate photon is scattered by the
object, then, using an $N$-photon point detector may reduce the Airy disk by a
factor of $N$.


title: The Graininess of Dark Matter Haloes

abstract:
  We use the recently completed one billion particle Via Lactea II LambdaCDM
simulation to investigate local properties like density, mean velocity,
velocity dispersion, anisotropy, orientation and shape of the velocity
dispersion ellipsoid, as well as structure in velocity space of dark matter
haloes. We show that at the same radial distance from the halo centre, these
properties can deviate by orders of magnitude from the canonical, spherically
averaged values, a variation that can only be partly explained by triaxiality
and the presence of subhaloes. The mass density appears smooth in the central
relaxed regions but spans four orders of magnitude in the outskirts, both
because of the presence of subhaloes as well as of underdense regions and holes
in the matter distribution. In the inner regions the local velocity dispersion
ellipsoid is aligned with the shape ellipsoid of the halo. This is not true in
the outer parts where the orientation becomes more isotropic. The clumpy
structure in local velocity space of the outer halo can not be well described
by a smooth multivariate normal distribution. Via Lactea II also shows the
presence of cold streams made visible by their high 6D phase space density.
Generally, the structure of dark matter haloes shows a high degree of
graininess in phase space that cannot be described by a smooth distribution
function.


title: Are red 2MASS QSOs young?

abstract:
  We use photometric data from Spitzer to explore the mid- and far-IR
properties of 10 red QSOs (J-K>2, R-K>5) selected by combining the 2MASS in the
NIR with the SDSS at optical wavelengths. Optical and/or near-infrared spectra
are available for 8/10 sources. Modeling the SED from UV to far-IR shows that
moderate dust reddening (A_V=1.3-3.2) can explain the red optical and near-IR
colours of the sources in the sample. There is also evidence that red QSOs have
60/12micron luminosity ratio higher than PG QSOs (97% significance). This can
be interpreted as a higher level of star-formation in these systems (measured
by the 60micron luminosity) for a given AGN power (approximated by the 12micron
luminosity). This is consistent with a picture where red QSOs represent an
early phase of AGN evolution, when the supermassive black hole is enshrouded in
dust and gas clouds, which will eventually be blown out (possibly by AGN driven
outflows) and the system will appear as typical optically luminous QSO. There
is also tentative evidence significant at the 96% level that red 2MASS QSOs are
more often associated with radio emission than optically selected SDSS QSOs.
This may indicate outflows, also consistent with the young AGN interpretation.
We also estimate the space density of red QSOs relative to optically selected
SDSS QSOs, taking into account the effect of dust extinction and the intrinsic
luminosity of the sources. We estimate that the fraction of red QSOs in the
overall population increases from 3% at M_K=-27.5mag to 12% at M_K=-29.5mag.
This suggests that reddened QSOs become more important at the bright end of the
Luminosity Function. If red QSOs are transition objects on the way to becoming
typical optically luminous QSOs, the low fractions above suggest that these
systems spent <12% of their lifetime at the "reddened" stage.


title: Strong Interactions for the LHC

abstract:
  Dynamical electroweak symmetry breaking (DEWSB) has been a viable option for
the completion of the standard model for over thirty years. Precision
electroweak studies indicate that the new strong interactions that break EW
symmetry cannot be a scaled-up copy of QCD. Building viable models of DEWSB is
difficult without a detailed understanding of such non-QCD gauge theories which
still confine and break chiral symmetry. We review past difficulties of
studying these theories using lattice methods and describe recent progress,
focusing on the role of approximate infrared conformal symmetry.


title:
Triggered Star Formation and the Creation of the Supergiant HI Shell in
  IC 2574

abstract:
  Based on deep imaging from the Advanced Camera for Surveys aboard the Hubble
Space Telescope, we present new evidence that stellar feedback created a ~ 1
kpc supergiant HI shell (SGS) and triggered star formation (SF) around its rim
in the M81 Group dwarf irregular galaxy IC 2574. Using photometry of the
resolved stars from the HST images, we measure the star formation history of a
region including the SGS, focusing on the past 500 Myr, and employ the unique
properties of blue helium burning stars to create a movie of SF in the SGS. We
find two significant episodes of SF inside the SGS from 200 - 300 Myr and ~ 25
Myr ago. Comparing the timing of the SF events to the dynamic age of the SGS
and the energetics from the HI and SF, we find compelling evidence that stellar
feedback is responsible for creating the SGS and triggering secondary SF around
its rim.


title: Off-center defects in crystals revisited: dynamic features

abstract:
  A survey is presented of the dynamic features of non-itinerant off-center
defects in crystals, such as rotation-like reorientation of isolated species by
either impurity or host ions. The occurrence of off-center displacements in
electron-vibrational mode systems is regarded as due to the vibronic effects.
It is extendable to systems in other fields of physics, e.g. nuclear matter.
The latter extension is found to be effective through re-scaling of energies
and separations.


title: Lovelock black holes with a nonlinear Maxwell field

abstract:
  We derive electrically charged black hole solutions of the
Einstein-Gauss-Bonnet equations with a nonlinear electrodynamics source in $n
(\ge 5)$ dimensions. The spacetimes are given as a warped product $M^2 \times
K^{n-2}$, where $K^{n-2}$ is a $(n-2)$-dimensional constant curvature space. We
establish a generalized Birkhoff's theorem by showing that it is the unique
electrically charged solution with this isometry and for which the orbit of the
warp factor on $K^{n-2}$ is non-null. An extension of the analysis for full
Lovelock gravity is also achieved with a particular attention to the
Chern-Simons case.


title: Symmetry and the generation and measurement of optical torque

abstract:
  A key element in the generation of optical torque in optical traps, which
occurs when electromagnetic angular momentum is transferred from the trapping
beam to the trapped particle by scattering, is the symmetries of the scattering
particle and the trapping beam. We discuss the effect of such symmetries on the
generation and measurement of optical torque in optical tweezers, and some
consequent general principles for the design of optically-driven micromachines.


title:
T-matrix calculation via discrete-dipole approximation, point matching
  and exploiting symmetry

abstract:
  We present a method of incorporating the discrete dipole approximation (DDA)
method with the point matching method to formulate the T-matrix for modeling
arbitrarily shaped micro-sized objects. The \emph{T}-matrix elements are
calculated using point matching between fields calculated using vector
spherical wave functions and DDA. When applied to microrotors, their discrete
rotational and mirror symmetries can be exploited to reduce memory usage and
calculation time by orders of magnitude; a number of optimization methods can
be employed based on the knowledge of the relationship between the azimuthal
mode and phase at each discrete rotational point, and mode redundancy from
Floquet's theorem. A 'reduced-mode' T-matrix can also be calculated if the
illumination conditions are known.


title:
Charged particle (pseudo-)rapidity distributions in
  proton+anti-proton/proton+proton and Pb+Pb/Au+Au collisions from SPS to LHC
  energies from UrQMD

abstract:
  We present results for final state charged particle (pseudo-)rapidity
distributions in $\rm{p}$ + $\bar{\rm{p}}$ / $\rm{p}$ + $\rm{p}$ and
Pb+Pb/Au+Au at ultra high energies (17.3 GeV $\leq$ $\sqrt{s_{\rm{NN}}}$ $\leq$
14 TeV) from the Ultra-relativistic Quantum Molecular Dynamics (UrQMD-v2.3)
model. In addition, excitation functions of produced charged particle
multiplicities ($N_{\rm{ch}}$) and pseudorapidity spectra are investigated up
to LHC energies. Good agreement is observed between UrQMD and measured
pseudorapidity distributions of charged particles up to the highest Tevatron
and Sp$\bar{\rm{p}}$S energies.


title: Generalized low-pass filters and multiresolution analyses

abstract:
  We study generalized filters that are associated to multiplicity functions
and homomorphisms of the dual of an abelian group. These notions are based on
the structure of generalized multiresolution analyses. We investigate when the
Ruelle operator corresponding to such a filter is a pure isometry, and then use
that characterization to study the problem of when a collection of closed
subspaces, which satisfies all the conditions of a GMRA except the trivial
intersection condition, must in fact have a trivial intersection. In this
context, we obtain a generalization of a theorem of Bownik and Rzeszotnik.


title: Computing p-adic integrals using motivic integration

abstract:
  We use the theory of motivic integration in order to give a geometric
explanation of the behavior of some p-adic integrals.


title:
Charge Renormalization, Thermodynamics, and Structure of Deionized
  Colloidal Suspensions

abstract:
  In charge-stabilized colloidal suspensions, highly charged macroions, dressed
by strongly correlated counterions, carry an effective charge that can be
substantially reduced (renormalized) from the bare charge. Interactions between
dressed macroions are screened by weakly correlated counterions and salt ions.
Thermodynamic and structural properties of colloidal suspensions depend
sensitively on the magnitudes of both the effective charge and the effective
screening constant. Combining a charge renormalization theory of effective
electrostatic interactions with Monte Carlo simulations of a one-component
model, we compute osmotic pressures and pair distribution functions of
deionized colloidal suspensions. This computationally practical approach yields
close agreement with corresponding results from large-scale simulations of the
primitive model up to modest electrostatic coupling strengths.


title:
Supersymmetry and other beyond the Standard Model physics: Prospects for
  determining mass, spin and CP properties

abstract:
  The prospects of measuring masses, spin and CP properties within
Supersymmetry and other beyond the Standard Model extensions at the LHC are
reviewed. Emphasis is put on models with missing transverse energy due to
undetected particles, as in Supersymmetry or Universal Extra Dimensions.


title:
Modeling H2 Fluorescence in Planetary Atmospheres with Partial Frequency
  Redistribution

abstract:
  We present the modeling of partial frequency redistribution (PRD) effects for
the fluorescent emission lines of molecular hydrogen, the general computational
approximations, and the applications to planetary atmospheres, as well as
interstellar medium. Our model is applied to FUSE observations of Jupiter,
Saturn, and reflection nebulae, allowing an independent confirmation of the H2
abundance and the structure of planetary atmospheres.


title:
Nonlocal Robin Laplacians and some remarks on a paper by Filonov on
  eigenvalue inequalities

abstract:
  The aim of this paper is twofold: First, we characterize an essentially
optimal class of boundary operators $\Theta$ which give rise to self-adjoint
Laplacians $-\Delta_{\Theta, \Omega}$ in $L^2(\Omega; d^n x)$ with (nonlocal
and local) Robin-type boundary conditions on bounded Lipschitz domains
$\Omega\subset\bbR^n$, $n\in\bbN$, $n\geq 2$. Second, we extend Friedlander's
inequalities between Neumann and Dirichlet Laplacian eigenvalues to those
between nonlocal Robin and Dirichlet Laplacian eigenvalues associated with
bounded Lipschitz domains $\Omega$, following an approach introduced by Filonov
for this type of problems.


title: Magnetic monopole and the nature of the static magnetic field

abstract:
  We investigate the factuality of the hypothetical magnetic monopole and the
nature of the static magnetic field. It is shown from many aspects that the
concept of the massive magnetic monopoles clearly is physically untrue. We
argue that the static magnetic field of a bar magnet, in fact, is the static
electric field of the periodically quasi-one-dimensional electric-dipole
superlattice, which can be well established in some transition metals with the
localized d-electron. This research may shed light on the perfect unification
of magnetic and electrical phenomena.


title: Consensus Answers for Queries over Probabilistic Databases

abstract:
  We address the problem of finding a "best" deterministic query answer to a
query over a probabilistic database. For this purpose, we propose the notion of
a consensus world (or a consensus answer) which is a deterministic world
(answer) that minimizes the expected distance to the possible worlds (answers).
This problem can be seen as a generalization of the well-studied inconsistent
information aggregation problems (e.g. rank aggregation) to probabilistic
databases. We consider this problem for various types of queries including SPJ
queries, \Topk queries, group-by aggregate queries, and clustering. For
different distance metrics, we obtain polynomial time optimal or approximation
algorithms for computing the consensus answers (or prove NP-hardness). Most of
our results are for a general probabilistic database model, called {\em and/xor
tree model}, which significantly generalizes previous probabilistic database
models like x-tuples and block-independent disjoint models, and is of
independent interest.


title:
Multipoint Schur algorithm and orthogonal rational functions:
  convergence properties, I

abstract:
  Classical Schur analysis is intimately connected to the theory of orthogonal
polynomials on the circle [Simon, 2005]. We investigate here the connection
between multipoint Schur analysis and orthogonal rational functions.
Specifically, we study the convergence of the Wall rational functions via the
development of a rational analogue to the Szeg\H o theory, in the case where
the interpolation points may accumulate on the unit circle. This leads us to
generalize results from [Khrushchev,2001], [Bultheel et al., 1999], and yields
asymptotics of a novel type.


title: Surveying the Phenomenology of General Gauge Mediation

abstract:
  I explore the phenomenology, constraints and tuning for several weakly
coupled implementations of multi-parameter gauge mediation and compare to
minimal gauge mediation. The low energy spectra are distinct from that of
minimal gauge mediation, a wide range of NLSPs is found and spectra are
significantly compressed thus tunings may be generically reduced to a part in
10 to a part in 20.


title:
MRC B0319-454: Probing the large-scale structure with a giant radio
  galaxy

abstract:
  We present an investigation of the relationships between the radio properties
of a giant radio galaxy MRC B0319-454 and the surrounding galaxy distribution
with the aim of examining the influence of intergalactic gas and gravity
associated with the large-scale structure on the evolution in the radio
morphology. Our new radio continuum observations of the radio source, with high
surface brightness sensitivity, images the asymmetries in the megaparsec-scale
radio structure in total intensity and polarization. We compare these with the
3-D galaxy distribution derived from galaxy redshift surveys. Galaxy density
gradients are observed along and perpendicular to the radio axis: the
large-scale structure is consistent with a model wherein the galaxies trace the
ambient intergalactic gas and the evolution of the radio structures are
ram-pressure limited by this associated gas. Additionally, we have modeled the
off-axis evolution of the south-west radio lobe as deflection of a buoyant jet
backflow by a transverse gravitational field: the model is plausible if
entrainment is small. The case study presented here is a demonstration that
giant radio galaxies may be useful probes of the warm-hot intergalactic medium
believed to be associated with moderately over dense galaxy distributions.


title:
Horizon formation and far-from-equilibrium isotropization in
  supersymmetric Yang-Mills plasma

abstract:
  Using gauge/gravity duality, we study the creation and evolution of
anisotropic, homogeneous strongly coupled $\mathcal N=4$ supersymmetric
Yang-Mills plasma. In the dual gravitational description, this corresponds to
horizon formation in a geometry driven to be anisotropic by a time-dependent
change in boundary conditions.


title: Left eigenvalues of $2\times 2$ symplectic matrices

abstract:
  We obtain a complete characterization of the $2\times 2$ symplectic matrices
having an infinite number of left eigenvalues. Previously, we give a new proof
of a result from Huang and So about the number of eigenvalues of a quaternionic
matrix. This is achieved by applying an algorithm for the resolution of
equations due to De Leo et al.


title: Index formulas on stratified manifolds

abstract:
  Elliptic operators on stratified manifolds with any finite number of strata
are considered. Under certain assumptions on the symbols of operators, we
obtain index formulas, which express index as a sum of indices of elliptic
operators on the strata.


title: Inegalite d'Ahlfors en dimension superieure

abstract:
  We proove an Ahlfors' like inequality for the holomorphic curves of a complex
compact Kobayashi hyperbolic manifold.


title: Growth-rate dependent partitioning of RNA polymerases in bacteria

abstract:
  Physiological changes which result in changes in bacterial gene expression
are often accompanied by changes in the growth rate for fast adapting enteric
bacteria. Since the availability of RNA polymerase (RNAP) in cells is dependent
on the growth rate, transcriptional control involves not only the regulation of
promoters, but also depends on the available (or free) RNAP concentration which
is difficult to quantify directly. Here we develop a simple physical model
describing the partitioning of cellular RNAP into different classes: RNAPs
transcribing mRNA and ribosomal RNA (rRNA), RNAPs non-specifically bound to
DNA, free RNAP, and immature RNAP. Available experimental data for E. coli
allow us to determine the two unknown parameters of the model and hence deduce
the free RNAP concentration at different growth rates. The results allow us to
predict the growth-rate dependence of the activities of constitutive
(unregulated) promoters, and to disentangle the growth-rate dependent
regulation of promoters (e.g., the promoters of rRNA operons) from changes in
transcription due to changes in the free RNAP concentration at different growth
rates. Our model can quantitatively account for the observed changes in gene
expression patterns in mutant E. coli strains with altered levels of RNAP
expression without invoking additional parameters. Applying our model to the
case of the stringent response following amino acid starvation, we can evaluate
the plausibility of various scenarios of passive transcriptional control
proposed to account for the observed changes in the expression of rRNA and
biosynthetic operons.


title:
Interplay of plasma-induced and fast thermal nonlinearities in a
  GaAs-based photonic crystal nanocavity

abstract:
  We investigate the nonlinear response of GaAs-based photonic crystal cavities
at time scales which are much faster than the typical thermal relaxation rate
in photonic devices. We demonstrate a strong interplay between thermal and
carrier induced nonlinear effects. We have introduced a dynamical model
entailing two thermal relaxation constants which is in very good agreement with
experiments. These results will be very important for Photonic Crystal-based
nonlinear devices intended to deal with practical high repetition rate optical
signals.


title: The Harish-Chandra isomorphism for Clifford algebras

abstract:
  We study the analogue of the Harish-Chandra homomorphism where the universal
enveloping algebra is replaced by the Clifford algebra, $Cl(g)$, of a
semisimple Lie algebra $g$. Two main goals are achieved. First, we prove that
there is a Harish-Chandra type isomorphism between the subalgebra of
$g$-invariants in $Cl(g)$ and the Clifford algebra of the Cartan subalgebra of
$g$. Second, the Cartan subalgebra is identified, via this isomorphism, with a
graded space of the so-called primitive skew-symmetric invariants of $g$. This
leads to a distinguished orthogonal basis of the Cartan subalgebra, which turns
out to be induced from the Lie algebra Langlands dual to $g$ via the action of
its principal three-dimensional subalgebra. This settles a conjecture of
Kostant.


title:
The impact of the 18F(a,p)21Ne reaction on fluorine production in AGB
  stars

abstract:
  The recent experimental evaluation of the 18F(a,p)21Ne reaction rate, when
considering its associated uncertainties, presented significant differences
compared to the theoretical Hauser-Feshbach rate. This was most apparent at the
low temperatures relevant for He-shell burning in asymptotic giant branch (AGB)
stars. Investigations into the effect on AGB nucleosynthesis revealed that the
upper limit resulted in an enhanced production of 19F and 21Ne in carbon-rich
AGB models, but the recommended and lower limits presented no differences from
using the theoretical rate. This was the case for models spanning a range in
metallicity from solar to [Fe/H] ~ -2.3. The results of this study are relevant
for observations of F and C-enriched AGB stars in the Galaxy, and to the Ne
composition of mainstream silicon carbide grains, that supposedly formed in the
outflows of cool, carbon-rich giant stars. We discuss the mechanism that
produces the extra F and summarize our main findings.


title:
Momentum-dependence of Superconducting Gap, strong-coupling dispersion
  Kink, and tightly bound Cooper pairs in the high-Tc (Sr,Ba)1-x(K,Na)xFe2As2
  superconductors

abstract:
  We present a systematic angle-resolved photoemission spectroscopic study of
the high-Tc superconductor class (Sr/Ba){1-x}(K/Na)xFe2As2. By utilizing a
photon-energy-modulation contrast and scattering geometry we report the Fermi
surface and the momentum dependence of the superconducting gap, Delta(k). A
prominent quasiparticle dispersion kink reflecting strong scattering processes
is observed in a binding-energy range of 25-55 meV in the superconducting
state, and the coherence length or the extent of the Cooper pair wave function
is found to be about 20-angstrom, which is uncharacteristic of a
superconducting phase realized by the BCS-phonon-retardation mechanism. The
observed 40 meV kink likely reflects contributions from the frustrated spin
excitations and scattering from the soft phonons. Results taken collectively
provide direct clues to the nature of the pairing potential including an
internal phase-shift factor in the superconducting order parameter which leads
to a Brillouin zone node in a strong-coupling setting.


title:
A formalism for the study of Natural Tensors Fields of type (0,2) on
  Manifolds and Fibrations

abstract:
  In order to study tensor fields of type (0,2) on manifolds and fibrations we
introduce the notion of s-spaces. With the help of these objects we generalized
the concept of natural tensor without making use of the theory of natural
operators and differential invariants.


title:
Evolution of Anemone AR NOAA 10798 and the Related Geo-Effective Flares
  and CMEs

abstract:
  We present a detailed examination of the features of the Active Region (AR)
NOAA 10798. This AR generated coronal mass ejections (CMEs) that caused a large
geomagnetic storm on 24 August 2005 with the minimum Dst index of -216 nT. We
examined the evolution of the AR and the features on/near the solar surface and
in the interplanetary space. The AR emerged in the middle of a small coronal
hole, and formed a {\it sea anemone} like configuration. H$\alpha$ filaments
were formed in the AR, which have southward axial field. Three M-class flares
were generated, and the first two that occurred on 22 August 2005 were followed
by Halo-type CMEs. The speeds of the CMEs were fast, and recorded about 1200
and 2400 km s$^{-1}$, respectively. The second CME was especially fast, and
caught up and interacted with the first (slower) CME during their travelings
toward Earth. These acted synergically to generate an interplanetary
disturbance with strong southward magnetic field of about -50 nT, which was
followed by the large geomagnetic storm.


title:
Non-crossing linked partitions and multiplication of free random
  variables

abstract:
  The material gives a new combinatorial proof of the multiplicative property
of the S-transform. In particular, several properties of the coefficients of
its inverse are connected to non-crossing linked partitions and planar trees.


title:
A photometric study of the southern Blazhko star SS For Unambiguous
  detection of quintuplet components

abstract:
  We present our analysis of photometric data in the Johnson B and V filter of
the southern Blazhko star SS For. In parallel, we analyzed the V observations
obtained with the ASAS-3 photometry of the star gathered between 2000 and 2008.
In the frequency spectra resulting from a Fourier analysis of our data, the
triplet structure is detectable up to high order, both in the B and V data.
Moreover, we find evidence for quintuplet components. We confirm from our data
that the modulation components decrease less steeply than the harmonics of the
main frequency. We derived the variations of the Fourier parameters quantifying
the light curve shape over the Blazhko cycle. There is good agreement between
the spectroscopic abundance and the metallicity determined from the Fourier
parameters of the average light curve. SS For is peculiar as a Blazhko star
because of its strong variations around minimum light.


title: Transformation from spots to waves in a model of actin pattern formation

abstract:
  Actin networks in certain single-celled organisms exhibit a complex
pattern-forming dynamics that starts with the appearance of static spots of
actin on the cell cortex. Spots soon become mobile, executing persistent random
walks, and eventually give rise to traveling waves of actin. Here we describe a
possible physical mechanism for this distinctive set of dynamic
transformations, by equipping an excitable reaction-diffusion model with a
field describing the spatial orientation of its chief constituent (which we
consider to be actin). The interplay of anisotropic actin growth and spatial
inhibition drives a transformation at fixed parameter values from static spots
to moving spots to waves.


title: Reconstructing $f(R)$ Theory from Ricci Dark Energy

abstract:
  In this letter, we regard the $f(R)$ theory as an effective description for
the acceleration of the universe and reconstruct the function $f(R)$ from the
Ricci dark energy, which respects holographic principle of quantum gravity. By
using different parameter $\alpha$ in RDE, we show the behaviors of
reconstructed $f(R)$ and find they are much different in the future.


title:
The excitation of spiral density waves through turbulent fluctuations in
  accretion discs I: WKBJ theory

abstract:
  We study and elucidate the mechanism of spiral density wave excitation in a
differentially rotating turbulent flow. We formulate a set of wave equations
with sources that are only non-zero in the presence of turbulent fluctuations.
We solve these in a shearing box domain using a WKBJ method. It is found that,
for a particular azimuthal wave length, the wave excitation occurs through a
sequence of regularly spaced swings during which the wave changes from leading
to trailing form. This is a generic process that is expected to occur in
shearing discs with turbulence. Trailing waves of equal amplitude propagating
in opposite directions are produced, both of which produce an outward angular
momentum flux that we give expressions for as functions of the disc parameters
and azimuthal wave length.
  By solving the wave amplitude equations numerically we justify the WKBJ
approach for a Keplerian rotation law for all parameter regimes of interest. In
order to quantify the wave excitation completely the important wave source
terms need to be specified. Assuming conditions of weak nonlinearity, these can
be identified and are associated with a quantity related to the potential
vorticity, being the only survivors in the linear regime. Under the additional
assumption that the source has a flat power spectrum at long azimuthal wave
lengths, the optimal azimuthal wave length produced is found to be determined
solely by the WKBJ response and is estimated to be 2 pi H, with H being the
nominal disc scale height.


title:
Full Gap Superconductivity in Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$ Probed by
  Muon Spin Rotation

abstract:
  Superfluid density ($n_s$) in the mixed state of an iron pnictide
superconductor Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$ is determined by muon spin
rotation for a sample with optimal doping ($x=0.4$). The temperature dependence
of $n_s$ is perfectly reproduced by the conventional BCS model for s-wave
paring, where the order parameter can be either a single-gap with
$\Delta=8.35(6)$ meV [$2\Delta/k_BT_c=5.09(4)$], or double-gap structure with
$\Delta_1=12$ meV (fixed) [$2\Delta_1/k_BT_c=7.3$] and $\Delta_2=6.8(3)$ meV
[$2\Delta_2/k_BT_c=4.1(2)$]. The latter is consistent with the recent result of
angle-resolved photo-emssion spectroscopy. The large gap parameters
($2\Delta/k_BT_c$) indicate extremely strong coupling of carriers to bosons
that mediate the Cooper pairing.


title:
First-principles study of hydrogen storage over Ni and Rh doped BN
  sheets

abstract:
  Absorption of hydrogen molecules on Nickel and Rhodium doped hexagonal boron
nitride(BN) sheet is investigated by using the first principle method. The most
stable site for the Ni atom was the on top side of nitrogen atom, while Rh
atoms deservers a hollow site over the hexagonal BN sheet. The first hydrogen
molecule was absorbed dissociatively over Rh atom, and molecularly on Ni doped
BN sheet. Both Ni and Rh atoms are capable to absorb up to three hydrogen
molecules chemically and the metal atom to BN sheet distance increases with the
increase in the number of hydrogen molecules. Finally, our calculations offer
explanation for the nature of bonding between the metal atom and the hydrogen
molecules, which is due to the hybridization of metal d orbital with the
hydrogen s orbital. These calculation results can be useful to understand the
nature of interaction between the doped metal and the BN sheet, and their
interaction with the hydrogen molecules.


title:
Difference of Oxide Hetero-Structure Junctions with Semiconductor
  Electronic Devices

abstract:
  Charge carrier injection performed in Pr0.7Ca0.3MnO3 (PCMO) hetero-structure
junctions exhibits stable without electric fields and dramatic changes in both
resistances and interface barriers, which are entirely different from behaviors
of semiconductor devices. Disappearance and reversion of interface barriers
suggest that the adjustable resistance switching of such hetero-structure oxide
devices should associate with motion of charge carriers across interfaces. The
results suggested that injected carriers should be still staying in devices and
resulted in changes in properties, which guided to a carrier self-trapping and
releasing picture in strongly correlated electronic framework. Observations in
PCMO and oxygen deficient CeO2 devices show that oxides as functional materials
could be used in microelectronics with some novel properties, in which
interface is very important.


title: Adatoms in Graphene

abstract:
  We review the problem of adatoms in graphene under two complementary points
of view, scattering theory and strong correlations. We show that in both cases
impurity atoms on the graphene surface present effects that are absent in the
physics of impurities in ordinary metals. We discuss how to observe these
unusual effects with standard experimental probes such as scanning tunneling
microscopes, and spin susceptibility.


title:
An effective-field-theory analysis of low-energy parity-violation in
  nucleon-nucleon scattering

abstract:
  We analyze parity-violating nucleon-nucleon scattering at energies
E<m_\pi^2/M using the effective field theory appropriate for this regime. The
minimal Lagrangian for short-range parity-violating NN interactions is written
in an operator basis that encodes the five partial-wave transitions that
dominate at these energies. We calculate the leading-order relationships
between parity-violating NN asymmetries and the coefficients in the Lagrangian
and also discuss the size of sub-leading corrections. We conclude with a
discussion of further observables needed to completely determine the
leading-order Lagrangian.


title: Geometrical Diagnostics for Generalized Chaplygin Gas

abstract:
  A new diagnostic method, $Om$ is applied to generalized Chaplygin gas (GCG)
model as the unification of dark matter and dark energy. On the basis of the
recently observed data: the Union supernovae, the observational Hubble data,
the SDSS baryon acoustic peak and the five-year WMAP shift parameter, we show
the discriminations between GCG and $\Lambda$CDM model. Furthermore, it is
calculated that the current equation of state of dark energy $w_{0de}=-0.964$
according to GCG model.


title: Astrophysical Probes of Unification

abstract:
  Traditional ideas for testing unification involve searching for the decay of
the proton and its branching modes. We point out that several astrophysical
experiments are now reaching sensitivities that allow them to explore
supersymmetric unified theories. In these theories the electroweak-mass DM
particle can decay, just like the proton, through dimension six operators with
lifetime ~ 10^26 sec. Interestingly, this timescale is now being investigated
in several experiments including ATIC, PAMELA, HESS, and Fermi. Positive
evidence for such decays may be opening our first direct window to physics at
the supersymmetric unification scale of M_GUT ~ 10^16 GeV, as well as the TeV
scale. Moreover, in the same supersymmetric unified theories, dimension five
operators can lead a weak-scale superparticle to decay with a lifetime of ~ 100
sec. Such decays are recorded by a change in the primordial light element
abundances and may well explain the present discord between the measured Li
abundances and standard big bang nucleosynthesis, opening another window to
unification. These theories make concrete predictions for the spectrum and
signatures at the LHC as well as Fermi.


title: Correction to the Moliere's formula for multiple scattering

abstract:
  The quasiclassical correction to the Moliere's formula for multiple
scattering is derived. The consideration is based on the scattering amplitude,
obtained with the first quasiclassical correction taken into account for
arbitrary localized but not spherically symmetric potential. Unlike the leading
term, the correction to the Moliere's formula contains the target density $n$
and thickness $L$ not only in the combination $nL$ (areal density). Therefore,
this correction can be reffered to as the bulk density correction. It turns out
that the bulk density correction is small even for high density. This result
explains the wide region of applicability of the Moliere's formula.


title:
Cascade of magnetic-field-induced quantum phase transitions in a spin
  $\bm{{1/2}}$ triangular-lattice antiferromagnet

abstract:
  We report magnetocaloric and magnetic-torque evidence that in
Cs$_{2}$CuBr$_{4}$ -- a geometrically frustrated Heisenberg $S=1/2$
triangular-lattice antiferromagnet -- quantum fluctuations stabilize a series
of spin states at simple increasing fractions of the saturation magnetization
$M_{s}$. Only the first of these states -- at $M={1/3}M_{s}$ -- has been
theoretically predicted. We discuss how the higher fraction quantum states
might arise and propose model spin arrangements. We argue that the first-order
nature of the transitions into those states is due to strong lowering of the
energies by quantum fluctuations, with implications for the general character
of quantum phase transitions in geometrically frustrated systems.


title:
Electrons on the surface of Bi2Se3 form a topologically-ordered two
  dimensional gas with a non-trivial Berry's phase

abstract:
  The interface between a superconductor and a topological insulator has been
proposed to harbor novel quasiparticles that realize physical schemes for
fault-tolerant quantum computation. Here, we present high resolution
angle-resolved photoemission experimental results, which along with first
principles calculations, suggest that the surface-edge states of Bi2Se3 form a
topological 2D metal. When magnetic atoms are deposited, the surface tends to
lose Kramers' degeneracy and a k-space connection thread between the bulk
valence and conduction bands is lost. Our observed states carry a \pi Berry's
phase suggesting that although the real materials are often electron doped
fully undoped Bi2Se3 would be a Z2 topological insulator at room temperature.


title:
Magnetic properties of undoped Cu2O fine powders with magnetic
  impurities and/or cation vacancies

abstract:
  Fine powders of micron- and submicron-sized particles of undoped Cu2O
semiconductor, with three different sizes and morphologies have been
synthesized by different chemical processes. These samples include nanospheres
200 nm in diameter, octahedra of size 1 micron, and polyhedra of size 800 nm.
They exhibit a wide spectrum of magnetic properties. At low temperature, T = 5
K, the octahedron sample is diamagnetic. The nanosphere is paramagnetic. The
other two polyhedron samples synthesized in different runs by the same process
are found to show different magnetic properties. One of them exhibits weak
ferromagnetism with T_C = 455 K and saturation magnetization, M_S = 0.19 emu/g
at T = 5 K, while the other is paramagnetic. The total magnetic moment
estimated from the detected impurity concentration of Fe, Co, and Ni, is too
small to account for the observed magnetism by one to two orders of magnitude.
Calculations by the density functional theory (DFT) reveal that cation
vacancies in the Cu2O lattice are one of the possible causes of induced
magnetic moments. The results further predict that the defect-induced magnetic
moments favour a ferromagnetically coupled ground state if the local
concentration of cation vacancies, n_C, exceeds 12.5%. This offers a possible
scenario to explain the observed magnetic properties. The limitations of the
investigations in the present work, in particular in the theoretical
calculations, are discussed and possible areas for further study are suggested.


title: Depth and Stanley depth of multigraded modules

abstract:
  We study the behavior of depth and Stanley depth along short exact sequences
of multigraded modules and under reduction modulo an element.


title: On an optimal quadrature formula in Sobolev space $L_2^{(m)} (0,1)$

abstract:
  In this paper in the space $L_2^{(m)}(0,1)$ the problem of construction of
optimal quadrature formulas is considered. Here the quadrature sum consists on
values of integrand at nodes and values of first derivative of integrand at the
end points of integration interval. The optimal coefficients are found and norm
of the error functional is calculated for arbitrary fixed $N$ and for any
$m\geq 2$. It is shown that when $m=2$ and $m=3$ the Euler-Maclaurin quadrature
formula is optimal.


title: Harmonic functions for a class of integro-differential operators

abstract:
  We consider the operator $\sL$ defined on $C^2(\bR^d)$ functions by \sL
f(x)&=&{1/2}\sum_{i,j=1}^d a_{ij}(x)\frac{\partial^2f(x)}{\partial x_i\partial
x_j}+\sum_{i=1}^d b_i(x)\frac{\partial f(x)}{\partial x_i}
&+&\int_{\bR^d\backslash\{0\}}[f(x+h)-f(x)-1_{(|h|\leq1)}h\cdot \grad
f(x)]n(x,h)dh. Under the assumption that the local part of the operator is
uniformly elliptic and with suitable conditions on $n(x,h)$, we establish a
Harnack inequality for functions that are nonnegative in $\bR^d$ and harmonic
in a domain. We also show that the Harnack inequality can fail without suitable
conditions on $n(x,h)$. A regularity theorem for those nonnegative harmonic
functions is also proved