title: Perturbative signature of substructures in strong gravitational lenses

abstract:
  In the perturbative approach, substructures in the lens can be reduced to
their effect on the two perturbative fields $f_1$ and $\frac{d f_0}{d\theta}$.
A simple generic model of elliptical lens with a substructure situated near the
critical radius is investigated in details. Analytical expressions are derived
for each perturbative field, and basic properties are analyzed. The power
spectrum of the fields is well approximated by a power-law, resulting in
significant tails at high frequencies. Another feature of the perturbation by a
substructure is that the ratio of the power spectrum at order $n$ of the 2
fields $R_n$ is nearly 1. The ratio $R_n \simeq 1$ is specific to
substructures, for instance an higher order distortion ($n>2$) but with
auto-similar isophotes will result in $R_n \propto \frac{1}{n^2}$. Finally, the
problem of reconstructing the perturbative field is investigated. Local field
model are implemented and fitted to maximize image similarity in the source
plane. The non-linear optimization is greatly facilitated, since in the
perturbative approach the circular source solution is always known. Examples of
images distortions in the subcritical regime due to substructures are
presented, and analyzed for different source shapes. Provided enough images and
signal is available, the substructure field can be identified confidently.
These results suggests that the perturbative method is an efficient tool to
estimate the contribution of substructures to the mass distribution of lenses.


title: Scaling properties of granular rheology near the jamming transition

abstract:
  Rheological properties of a dense granular material consisting of
frictionless spheres are investigated. It is found that the shear stress, the
pressure, and the kinetic temperature obey critical scaling near the jamming
transition point, which is considered as a critical point. These scaling laws
have some peculiar properties in view of conventional critical phenomena
because the exponents depend on the interparticle force models so that they are
not universal. It is also found that these scaling laws imply the relation
between the exponents that describe the growing correlation length.


title: Every 4-Manifold is BLF

abstract:
  Here we show that every compact smooth 4-manifold X has a structure of a
Broken Lefschetz Fibration (BLF in short). Furthermore, if b_{2}^{+}(X)> 0 then
it also has a Broken Lefschetz Pencil structure (BLP) with nonempty base locus.
This imroves a Theorem of Auroux, Donaldson and Katzarkov, and our proof is
topological (i.e. uses 4-dimensional handlebody theory).


title: Testing the proposed link between cosmic rays and cloud cover

abstract:
  A decrease in the globally averaged low level cloud cover, deduced from the
ISCCP infra red data, as the cosmic ray intensity decreased during the solar
cycle 22 was observed by two groups. The groups went on to hypothesise that the
decrease in ionization due to cosmic rays causes the decrease in cloud cover,
thereby explaining a large part of the presently observed global warming. We
have examined this hypothesis to look for evidence to corroborate it. None has
been found and so our conclusions are to doubt it. From the absence of
corroborative evidence, we estimate that less than 23%, at the 95% confidence
level, of the 11-year cycle change in the globally averaged cloud cover
observed in solar cycle 22 is due to the change in the rate of ionization from
the solar modulation of cosmic rays.


title:
Stability of the Bloch wall via the Bogomolnyi decomposition in elliptic
  coordinates

abstract:
  We consider the one-dimensional anisotropic XY model in the continuum limit.
Stability analysis of its Bloch wall solution is hindered by the nondiagonality
of the associated linearised operator and the hessian of energy. We circumvent
this difficulty by showing that the energy admits a Bogomolnyi bound in
elliptic coordinates and that the Bloch wall saturates it -- that is, the Bloch
wall renders the energy minimum. Our analysis provides a simple but nontrivial
application of the BPS (Bogomolnyi - Prasad - Sommerfield) construction in one
dimension, where its use is often believed to be limited to reproducing results
obtainable by other means.


title: Mutual Chern-Simons theory for Z_2 topological order

abstract:
  We study several different $Z_2$ topological ordered states in frustrated
spin systems. The effective theories for those different Z_2 topological orders
all have the same form -- a Z_2 gauge theory which can also be written as a
mutual U(1) x U(1) Chern-Simons theory. However, we find that the different Z_2
topological orders are reflected in different projective realizations of
lattice symmetry in the same effective mutual Chern-Simons theory. This result
is obtained by comparing the ground-state degeneracy, the ground-state quantum
numbers, the gapless edge state, and the projective symmetry group of
quasi-particles calculated from the slave-particle theory and from the
effective mutual Chern-Simons theories. Our study reveals intricate relations
between topological order and symmetry.


title: K\"ahler and Sasakian-Einstein Quotients

abstract:
  We construct symplectic and K\"ahler ray reduced spaces and discuss their
relation with the Marsden-Weinstein (point) reduction. This K\"ahler reduction
is well defined even when the momentum value is not totally isotropic. The
compatibility of the ray reduction with the cone construction and the
Boothby-Wang fibration is presented. Using the compatibility with the cone
construction we provide the exact description of ray quotients of cotangent
bundles. Some applications of the ray reduction to the study of conformal
Hamiltonian systems are described. We also give necessary and sufficient
conditions for the (ray) quotients of K\"ahler (Sasakian)-Einstein manifolds to
be again K\"ahler (Sasakian)-Einstein.


title:
On perpetual American put valuation and first-passage in a
  regime-switching model with jumps

abstract:
  In this paper we consider the problem of pricing a perpetual American put
option in an exponential regime-switching L\'{e}vy model. For the case of the
(dense) class of phase-type jumps and finitely many regimes we derive an
explicit expression for the value function. The solution of the corresponding
first passage problem under a state-dependent level rests on a path
transformation and a new matrix Wiener-Hopf factorization result for this class
of processes.


title: The nontrivial zeros of the Zeta Function lie on the Critical Line

abstract:
  In this paper is stablished a characterization of the solutions of the
equation: zeta(z) = 0. Then such a characterization is used to give a proof for
Riemann is Conjecture.


title:
Simultaneous loss and excitation of projectile electrons in relativistic
  collisions of U$^{90+}$(1s$^2$) ions with atoms

abstract:
  We study relativistic collisions between helium-like uranium ions initially
in the ground state and atoms in which, in a single collision event, one of the
electrons of the ion is emitted and the other is transferred into an excited
state of the residual hydrogen-like ion. We consider this two-electron process
at not very high impact energies, where the action of the atom on the electrons
of the ion can be well approximated as occurring solely due to the interaction
with the nucleus of the atom and, hence, the process can be regarded as a
four-body problem. Using the independent electron model we show that a very
substantial improvement in the calculated cross sections is obtained if,
instead of the first order approximation, the relativistic symmetric eikonal
and continuum-distorted-wave-eikonal-initial-state models are employed to
describe the single-electron probabilities for the excitation and loss,
respectively.


title: The Abella Interactive Theorem Prover (System Description)

abstract:
  Abella is an interactive system for reasoning about aspects of object
languages that have been formally presented through recursive rules based on
syntactic structure. Abella utilizes a two-level logic approach to
specification and reasoning. One level is defined by a specification logic
which supports a transparent encoding of structural semantics rules and also
enables their execution. The second level, called the reasoning logic, embeds
the specification logic and allows the development of proofs of properties
about specifications. An important characteristic of both logics is that they
exploit the lambda tree syntax approach to treating binding in object
languages. Amongst other things, Abella has been used to prove normalizability
properties of the lambda calculus, cut admissibility for a sequent calculus and
type uniqueness and subject reduction properties. This paper discusses the
logical foundations of Abella, outlines the style of theorem proving that it
supports and finally describes some of its recent applications.


title:
Tableau-based decision procedures for logics of strategic ability in
  multi-agent systems

abstract:
  We develop an incremental tableau-based decision procedures for the
  Alternating-time temporal logic ATL and some of its variants.
  While running within the theoretically established complexity upper bound, we
claim that our tableau is practically more efficient in the average case than
other decision procedures for ATL known so far. Besides, the ease of its
adaptation to variants of ATL demonstrates the flexibility of the proposed
procedure.


title: The effective Coulomb potential in SU(3) lattice Yang-Mills theory

abstract:
  We study the infrared behavior of the effective Coulomb potential in lattice
SU(3) Yang-Mills theory in the Coulomb gauge. We use lattices up to a size of
48^4 and three values of the inverse coupling, beta=5.8, 6.0 and 6.2. While
finite-volume effects are hardly visible in the effective Coulomb potential,
scaling violations and a strong dependence on the choice of Gribov copy are
observed. We obtain bounds for the Coulomb string tension that are in agreement
with Zwanziger's inequality relating the Coulomb string tension to the Wilson
string tension.


title: Betrachtungen jenseits des Standardmodells der Teilchenphysik

abstract:
  Gravity with incorporation of additional dimensions and noncommutative
geometry.


title: Cosmic Microwave Weak lensing data as a test for the dark universe

abstract:
  Combined analyses of WMAP 3-year and ACBAR Cosmic Microwave Anisotropies
angular power spectra have presented evidence for gravitational lensing >3
sigma level. This signal could provide a relevant test for cosmology. After
evaluating and confirming the statistical significance of the detection in
light of the new WMAP 5-year data, we constrain a new parameter A_L that scales
the lensing potential such that A_L=0 corresponds to unlensed while A_L=1 is
the expected lensed result. We find from WMAP5+ACBAR a 2.5 sigma indication for
a lensing contribution larger than expected, with A_L=3.1_{-1.5}^{+1.8} at 95%
c.l.. The result is stable under the assumption of different templates for an
additional Sunyaev-Zel'dovich foreground component or the inclusion of an extra
background of cosmic strings. We find negligible correlation with other
cosmological parameters as, for example, the energy density in massive
neutrinos. While unknown systematics may be present, dark energy or modified
gravity models could be responsible for the over-smoothness of the power
spectrum. Near future data, most notably from the Planck satellite mission,
will scrutinize this interesting possibility.


title:
A Hybrid N-Body Code Incorporating Algorithmic Regularization and
  Post-Newtonian Forces

abstract:
  We describe a novel N-body code designed for simulations of the central
regions of galaxies containing massive black holes. The code incorporates
Mikkola's 'algorithmic' chain regularization scheme including post-Newtonian
terms up to PN2.5 order. Stars moving beyond the chain are advanced using a
fourth-order integrator with forces computed on a GRAPE board. Performance
tests confirm that the hybrid code achieves better energy conservation, in less
elapsed time, than the standard scheme and that it reproduces the orbits of
stars tightly bound to the black hole with high precision. The hybrid code is
applied to two sample problems: the effect of finite-N gravitational
fluctuations on the orbits of the S-stars; and inspiral of an intermediate-mass
black hole into the galactic center.


title:
A bijective proof of a factorization formula for Macdonald polynomials
  at roots of unity

abstract:
  We give a combinatorial proof of the factorization formula of modified
Macdonald polynomials when the parameter t is specialized at a primitive root
of unity. Our proof is restricted to the special case of partitions with 2
columns. We mainly use the combinatorial interpretation of Haglund, Haiman and
Loehr giving the expansion of the modified Macdonald polynomials on the
monomial basis.


title:
Effects of disorder on atomic density waves and spin-singlet dimers in
  one-dimensional optical lattices

abstract:
  Using the Bethe-ansatz density-functional theory, we study a one-dimensional
Hubbard model of confined attractively interacting fermions in the presence of
a uniformly distributed disorder. The strongly-correlated Luther-Emery nature
of the attractive one-dimensional Hubbard model is fully taken into account as
the reference system in the density-functional theory. The effects of the
disorder are investigated on the atomic-density waves in the
weak-to-intermediate attractive interaction and on the spin-singlet dimers of
doubly occupied sites in the strongly attractive regime. It is found that
atomic density waves are sensitive to the disorder and the spin-singlet dimers
of doubly occupied sites are quite unstable against the disorder. We also show
that very weak disorder could smear the singularities in the stiffness, thus
suppress the spin-singlet pairs.


title:
Constraints on the Number Density of Evaporating Primordial Black Holes
  for the Chromospheric Evaporation Models

abstract:
  Cosmic gamma-ray bursts with primary-photon energies > 10 GeV are sought in
the data from the Andyrchy array obtained in the mode of detection of a single
cosmic-ray component during a net observation period of 2005.4 d. The
distribution of fluctuations of the detector counting rate agrees with the
expected cosmic-ray background, the only exception being an event with a
deviation of 7.9 sigma. Constraints on the number density of evaporating
primordial black holes in a local region of the Galaxy are obtained for the
chromospheric evaporation models.


title: Problem Solving and Complex Systems

abstract:
  The observation and modeling of natural Complex Systems (CSs) like the human
nervous system, the evolution or the weather, allows the definition of special
abilities and models reusable to solve other problems. For instance, Genetic
Algorithms or Ant Colony Optimizations are inspired from natural CSs to solve
optimization problems. This paper proposes the use of ant-based systems to
solve various problems with a non assessing approach. This means that solutions
to some problem are not evaluated. They appear as resultant structures from the
activity of the system. Problems are modeled with graphs and such structures
are observed directly on these graphs. Problems of Multiple Sequences Alignment
and Natural Language Processing are addressed with this approach.


title: Science mapping with asymmetrical paradigmatic proximity

abstract:
  We propose a series of methods to represent the evolution of a field of
science at different levels: namely micro, meso and macro levels. We use a
previously introduced asymmetric measure of paradigmatic proximity between
terms that enables us to extract structure from a large publications database.
We apply our set of methods on a case study from the complex systems community
through the mapping of more than 400 complex systems science concepts indexed
from a database as large as several millions of journal papers. We will first
summarize the main properties of our asymmetric proximity measure. Then we show
how salient paradigmatic fields can be embedded into a 2-dimensional
visualization into which the terms are plotted according to their relative
specificity and generality index. This meso-level helps us producing
macroscopic maps of the field of science studied featuring the former
paradigmatic fields.


title: On the CNOT-cost of TOFFOLI gates

abstract:
  The three-input TOFFOLI gate is the workhorse of circuit synthesis for
classical logic operations on quantum data, e.g., reversible arithmetic
circuits. In physical implementations, however, TOFFOLI gates are decomposed
into six CNOT gates and several one-qubit gates. Though this decomposition has
been known for at least 10 years, we provide here the first demonstration of
its CNOT-optimality.
  We study three-qubit circuits which contain less than six CNOT gates and
implement a block-diagonal operator, then show that they implicitly describe
the cosine-sine decomposition of a related operator. Leveraging the canonicity
of such decompositions to limit one-qubit gates appearing in respective
circuits, we prove that the n-qubit analogue of the TOFFOLI requires at least
2n CNOT gates. Additionally, our results offer a complete classification of
three-qubit diagonal operators by their CNOT-cost, which holds even if ancilla
qubits are available.


title: Lissom, a Source Level Proof Carrying Code Platform

abstract:
  This paper introduces a proposal for a Proof Carrying Code (PCC) architecture
called Lissom. Started as a challenge for final year Computing students, Lissom
was thought as a mean to prove to a sceptic community, and in particular to
students, that formal verification tools can be put to practice in a realistic
environment, and be used to solve complex and concrete problems. The
attractiveness of the problems that PCC addresses has already brought students
to show interest in this project.


title: Global integrability of cosmological scalar fields

abstract:
  We investigate the Liouvillian integrability of Hamiltonian systems
describing a universe filled with a scalar field (possibly complex). The tool
used is the differential Galois group approach, as introduced by Morales-Ruiz
and Ramis. The main result is that the generic systems with minimal coupling
are non-integrable, although there still exist some values of parameters for
which integrability remains undecided; the conformally coupled systems are only
integrable in four known cases. We also draw a connection with chaos present in
such cosmological models, and the issues of integrability restricted to the
real domain.


title:
Two Algorithms for Solving A General Backward Pentadiagonal Linear
  Systems

abstract:
  In this paper we present an efficient computational and symbolic algorithms
for solving a backward pentadiagonal linear systems. The implementation of the
algorithms using Computer Algebra Systems (CAS) such as MAPLE, MACSYMA,
MATHEMATICA, and MATLAB are straightforward. An examples are given in order to
illustrate the algorithms. The symbolic algorithm is competitive the other
methods for solving a backward pentadiagonal linear systems.


title:
Representations of dynamical systems on Banach spaces not containing
  $l_1$

abstract:
  For a topological group G, we show that a compact metric G-space is tame if
and only if it can be linearly represented on a separable Banach space which
does not contain an isomorphic copy of $l_1$ (we call such Banach spaces,
Rosenthal spaces). With this goal in mind we study tame dynamical systems and
their representations on Banach spaces.


title: The Melting Line of Hydrogen at High Pressures

abstract:
  The insulator to metal transition in solid hydrogen was predicted over 70
years ago but the demonstration of this transition remains a scientific
challenge. In this regard, a peak in the temperature vs. pressure melting line
of hydrogen may be a possible precursor for metallization. However, previous
measurements of the fusion curve of hydrogen have been limited in pressure by
diffusion of hydrogen into the gasket or diamonds. To overcome this limitation
we have used an innovative technique of pulsed laser heating of the sample and
final peak in the melting line at P=64.7+-4GPa and T=1055+-20 K.


title:
Apriori Estimates for Many-Body Hamiltonian Evolution of Interacting
  Boson System

abstract:
  We study the evolution of a many-particle system whose wave function obeys
the N-body Schroedinger equation under Bose symmetry. The system Hamiltonian
describes pairwise particle interactions in the absence of an external
potential. We derive apriori dispersive estimates that express the overall
repulsive nature of the particle interactions. These estimates hold for a wide
class of two-body interaction potentials which are independent of the particle
number, N. We discuss applications of these estimates to the BBGKY hierarchy
for reduced density matrices analyzed by Elgart, Erdos, Schlein and Yau.


title: Simulations of minor mergers. I. General properties of thick disks

abstract:
  We present simulations of the formation of thick disks via the accretion of
two-component satellites onto a pre-existing thin disk. Our goal is to
establish the detailed characteristics of the thick disks obtained in this way,
as well as their dependence on the initial orbital and internal properties of
the accreted objects. We find that mergers with 10-20% mass of the mass of the
host lead to the formation of thick disks whose characteristics are similar,
both in morphology as in kinematics, to those observed. Despite the relatively
large mass ratios, the host disks are not fully destroyed by the infalling
satellites: a remaining kinematically cold and thin component containing
~15-25% of the mass can be identified, which is embedded in a hotter and
thicker disk. This may for example, explain the existence of a very old thin
disk stars in the Milky Way. The final scale-heights of the disks depend both
on the initial inclination and properties of the merger, but the fraction of
satellite stellar particles at ~4 scale-heights directly measures the mass
ratio between the satellite and host galaxy. Our thick disks typically show
boxy isophotes at very low surface brightness levels (>6 magnitudes below their
peak value). Kinematically, the velocity ellipsoids of the simulated thick
disks are similar to that of the Galactic thick disk at the solar radius. The
trend of sigma_Z/sigma_R with radius is found to be a very good discriminant of
the initial inclination of the accreted satellite. In the Milky Way, the
possible existence of a vertical gradient in the rotational velocity of the
thick disk as well as the observed value of sigma_Z/sigma_R at the solar
vicinity appear to favour the formation of the thick disk by a merger with
either low or intermediate orbital inclination.


title: Interacting finite-size magnons

abstract:
  We explicitly construct a large class of finite-volume two-magnon string
solutions moving on R x S^2. In particular, by making use of the relationship
between the O(3) sigma model and sine-Gordon theory we are able to find
solutions corresponding to the periodic analogues of magnon scattering and
breather-like solutions. After semi-classically quantizing these solutions we
invert the implicit expressions for the excitation energies in certain limits
and find the corrections for the multi-magnon states. For the breather-like
solutions we express the energies directly in terms of the action variable
whereas for the scattering solution we express the result as a combination of
corrections to the dispersion relation and to the scattering phase.


title: When is a symmetric pin-jointed framework isostatic?

abstract:
  Maxwell's rule from 1864 gives a necessary condition for a framework to be
isostatic in 2D or in 3D. Given a framework with point group symmetry, group
representation theory is exploited to provide further necessary conditions.
This paper shows how, for an isostatic framework, these conditions imply very
simply stated restrictions on the numbers of those structural components that
are unshifted by the symmetry operations of the framework. In particular, it
turns out that an isostatic framework in 2D can belong to one of only six point
groups. Some conjectures and initial results are presented that would give
sufficient conditions (in both 2D and 3D) for a framework that is realized
generically for a given symmetry group to be an isostatic framework.


title: Decomposition numbers for perverse sheaves

abstract:
  The purpose of this article is to set foundations for decomposition numbers
of perverse sheaves, to give some methods to calculate them in simple cases,
and to compute them concretely in two situations: for a simple (Kleinian)
surface singularity, and for the closure of the minimal non-trivial orbit in a
simple Lie algebra.
  This work has applications to modular representation theory, for Weyl groups
using the nilpotent cone of the corresponding semisimple Lie algebra, and for
reductive algebraic group schemes using the affine Grassmannian of the
Langlands dual group.


title: Twisted K-theory and finite-dimensional approximation

abstract:
  We provide a finite-dimensional model of the twisted K-group twisted by any
degree three integral cohomology class of a CW complex. One key to the model is
Furuta's generalized vector bundle, and the other is a finite-dimensional
approximation of Fredholm operators.


title: Quantum Phase Extraction in Isospectral Electronic Nanostructures

abstract:
  Quantum phase is not a direct observable and is usually determined by
interferometric methods. We present a method to map complete electron wave
functions, including internal quantum phase information, from measured
single-state probability densities. We harness the mathematical discovery of
drum-like manifolds bearing different shapes but identical resonances, and
construct quantum isospectral nanostructures possessing matching electronic
structure but divergent physical structure. Quantum measurement (scanning
tunneling microscopy) of these "quantum drums" [degenerate two-dimensional
electron states on the Cu(111) surface confined by individually positioned CO
molecules] reveals that isospectrality provides an extra topological degree of
freedom enabling robust quantum state transplantation and phase extraction.


title:
A Taylor expansion theorem for an elliptic extension of the Askey-Wilson
  operator

abstract:
  We establish Taylor series expansions in rational (and elliptic) function
bases using E. Rains' elliptic extension of the Askey-Wilson divided difference
operator. The expansion theorem we consider extends M.E.H. Ismail's expansion
for the Askey-Wilson monomial basis. Three immediate applications (essentially
already due to Rains) include simple proofs of Frenkel and Turaev's elliptic
extensions of Jackson's 8-phi-7 summation and of Bailey's 10-phi-9
transformation, and the computation of the connection coefficients of
Spiridonov's elliptic extension of Rahman's biorthogonal rational functions. We
adumbrate other examples including the nonterminating extension of Jackson's
8-phi-7 summation and a quadratic expansion.


title:
A Sort of Relation among a Dissipative Mechanical System and
  Conservative Ones

abstract:
  In this paper we proposed a proposition: for any nonconservative classical
mechanical system and any initial condition, there exists a conservative one;
the two systems share one and only one common phase curve; the Hamiltonian of
the conservative system is the sum of the total energy of the nonconservative
system on the aforementioned phase curve and a constant depending on the
initial condition. Hence, this approach entails substituting an infinite number
of conservative systems for a dissipative mechanical system corresponding to
varied initial conditions. One key way we use to demonstrate these viewpoints
is that by the Newton-Laplace principle the nonconservative force can be
reasonably assumed to be equal to a function of a component of generalized
coordinates $q_i$ along a phase curve, such that a nonconservative mechanical
system can be reformulated as countless conservative systems. Utilizing the
proposition, one can apply the method of Hamiltonian mechanics or Lagrangian
mechanics to dissipative mechanical system. The advantage of this approach is
that there is no need to change the definition of canonical momentum and the
motion is identical to that of the original system.


title:
Consistent Computation of First- and Second-Order Differential
  Quantities for Surface Meshes

abstract:
  Differential quantities, including normals, curvatures, principal directions,
and associated matrices, play a fundamental role in geometric processing and
physics-based modeling. Computing these differential quantities consistently on
surface meshes is important and challenging, and some existing methods often
produce inconsistent results and require ad hoc fixes. In this paper, we show
that the computation of the gradient and Hessian of a height function provides
the foundation for consistently computing the differential quantities. We
derive simple, explicit formulas for the transformations between the first- and
second-order differential quantities (i.e., normal vector and principal
curvature tensor) of a smooth surface and the first- and second-order
derivatives (i.e., gradient and Hessian) of its corresponding height function.
We then investigate a general, flexible numerical framework to estimate the
derivatives of the height function based on local polynomial fittings
formulated as weighted least squares approximations. We also propose an
iterative fitting scheme to improve accuracy. This framework generalizes
polynomial fitting and addresses some of its accuracy and stability issues, as
demonstrated by our theoretical analysis as well as experimental results.


title: Partial order from disorder in a classical pyrochlore antiferromagnet

abstract:
  We investigate theoretically the phase diagram of a classical Heisenberg
antiferromagnet on the pyrochlore lattice perturbed by a weak second-neighbor
interaction J_2. The huge ground state degeneracy of the nearest-neighbor
Heisenberg spins is lifted by J_2 and a magnetically ordered ground state sets
in upon approaching zero temperature. We have found a new, partially ordered
phase with collinear spins at finite temperatures for a ferromagnetic J_2. In
addition to a large nematic order parameter, this intermediate phase also
exhibits a layered structure and a bond order that breaks the sublattice
symmetry. Thermodynamic phase boundaries separating it from the fully
disordered and magnetically ordered states scale as 1.87 J_2 S^2 and 0.26 J_2
S^2 in the limit of small J_2. The phase transitions are discontinuous. We
analytically examine the local stability of the collinear state and obtain a
boundary T ~ J_2^2/J_1 in agreement with Monte Carlo simulations.


title:
Symmetric ordering effect on Casimir energy in $\kappa-$Minkowski
  spacetime

abstract:
  We present the Casimir energy of spherical shell, for the symmetrically
deformed scalar field in $\kappa$-Minkowski space-time, satisfying Dirichlet
boundary condition. The Casimir energy shows the particle anti-particle
symmetry contrary to the asymmetrically deformed case. In addition, the
deformation effect starts from $O(1/\kappa)$ term unlike in the parallel
plates.


title:
Perfect transference of a d-level quantum state over
  pseudo-distance-regular networks

abstract:
  Following the prescription of Ref. \cite{PST} in which perfect state
transference (PST) of a qubit over distance regular spin networks was
discussed, in this paper PST of an arbitrary $d$-level quantum state (qudit)
over antipodes of more general networks called pseudo distance-regular
networks, is investigated. In fact, the spectral analysis techniques used in
the previous work \cite{PST}, and algebraic structures of pseudo
distance-regular graphs are employed to give an explicit formula for suitable
coupling constants in the Hamiltonians so that the state of a particular qudit
initially encoded on one site will evolve freely to the opposite site without
any dynamical control, i.e., we show that how to derive the parameters of the
system so that PST can be achieved.
  Keywords:Perfect state transfer, $d$-level quantum state, Stratification,
Pseudo-distance-regular network
  PACs Index: 01.55.+b, 02.10.Yn


title: Rapidly Spinning Black Holes in Quasars: An Open Question

abstract:
  Wang et al. (2006) estimated an average radiative efficiency of 30% -- 35%
for quasars at moderate redshift. We find that their method is not independent
of quasar lifetimes and thus that quasars do not necessarily have such high
efficiencies. Nonetheless, it is possible to derive interrelated constraints on
quasar lifetimes, Eddington ratios, and radiative efficiencies of supermassive
black holes. We derive such constraints using a statistically complete sample
of quasars with black hole mass estimates from broad Mg II, made both with and
without the radiation pressure correction of Marconi et al. (2008). We conclude
that for quasars with L/LEdd > 0.02, lifetimes can range from 140 to 750 Myr
for Schwarzschild black holes. Coupled with observed black hole masses, quasar
lifetimes of < 140 Myr would imply that radiatively inefficient accretion or BH
mergers must be important in the accretion history of quasars. Given reasonable
assumptions about the quasar population, if the average quasar lifetime is < 1
Gyr, and if radiatively inefficient accretion is unimportant, then not many BHs
with Eddington ratio < 0.2 can be rapidly spinning.


title: On the size of Kakeya sets in finite fields

abstract:
  A Kakeya set is a subset of F^n, where F is a finite field of q elements,
that contains a line in every direction. In this paper we show that the size of
every Kakeya set is at least C_n * q^n, where C_n depends only on n. This
improves the previously best lower bound for general n of ~q^{4n/7}.


title: Data Fusion Trees for Detection: Does Architecture Matter?

abstract:
  We consider the problem of decentralized detection in a network consisting of
a large number of nodes arranged as a tree of bounded height, under the
assumption of conditionally independent, identically distributed observations.
We characterize the optimal error exponent under a Neyman-Pearson formulation.
We show that the Type II error probability decays exponentially fast with the
number of nodes, and the optimal error exponent is often the same as that
corresponding to a parallel configuration. We provide sufficient, as well as
necessary, conditions for this to happen. For those networks satisfying the
sufficient conditions, we propose a simple strategy that nearly achieves the
optimal error exponent, and in which all non-leaf nodes need only send 1-bit
messages.


title: Interval valued $(\in,\ivq)$-fuzzy filters of pseudo $BL$-algebras

abstract:
  We introduce the concept of quasi-coincidence of a fuzzy interval value with
an interval valued fuzzy set. By using this new idea, we introduce the notions
of interval valued $(\in,\ivq)$-fuzzy filters of pseudo $BL$-algebras and
investigate some of their related properties. Some characterization theorems of
these generalized interval valued fuzzy filters are derived. The relationship
among these generalized interval valued fuzzy filters of pseudo $BL$-algebras
is considered. Finally, we consider the concept of implication-based interval
valued fuzzy implicative filters of pseudo $BL$-algebras, in particular, the
implication operators in Lukasiewicz system of continuous-valued logic are
discussed.


title:
Effects of Zero Mode and Thin Spectrum on the Life Time of Atomic Bose
  Einstein Condensates

abstract:
  Reviewing the ideas developed in, the ground state life time of a finite size
atomic Bose Einstein condensate is studied for coherent, squeezed coherent and
thermal coherent ground states. Ground state evolution of coherent and squeezed
coherent states in a double well potential is studied. Effects of thin spectrum
on Bose-Einstein condensates is discussed and quasiparticle excitation
lifetimes are calculated. It is shown that the effect of the states we use on
the free energy vanishes in the thermodynamic limit. Possible extension to a
double well potential and effect of a second broken symmetry is also discussed.


title: Noncommutative Standard Model in Top Quark Sector

abstract:
  In this article we aim to estimate the bounds on the noncommutative scale
$\Lambda_{NC}$ and to extract the 95% exclusion contours for some
$\theta_{\mu\nu}$ components using the recent measurements of the top quark
width and the $W$ boson polarization in top pair events from CDF experiment at
Tevatron.


title: Studies on the equations of Ince's table

abstract:
  We study the phase space of the equations of Ince's table from the viewpoint
of its accessible singularities and local index.


title: Reaction pp-> {pp}_s pi^0 in the GeV region and pi^0 p rescattering

abstract:
  COSY data on the cross section of the reaction pp -> {pp}_s pi^0, where
{pp}_s is the proton pair in the 1S0 state at small excitation energy
E_{pp}=0-3 MeV, recently obtained for beam energies 0.5 - 2.0 GeV are analyzed
within the one-pion exchange model. The model is based on the subprocess pi^0 p
-> pi^0 p and final state pp-interaction. A broad maximum observed in the
energy dependence of the cross section at 0.5 - 1.4 GeV in the forward
direction is explained by this model as a dominant contribution of the isospin
3/2 in the pi^0 p-rescattering. The second maximum observed at 2 GeV is
underpredicted within the model by one order of magnitude.


title: Continuous Decoupling of Dynamically Expanding Systems

abstract:
  The question of decoupling and freeze-out is reinvestigated and analysed in
terms of transparent semi-classical decoupling formulae, which provide a smooth
decoupling in time both, for single and two particle inclusive spectra. They
generalise frequently employed instantaneous freeze-out procedures and provide
simple relations between the damping width and the duration of the decoupling
process. The implications on physical phenomena arising from the expansion and
decay dynamics of the highly compressed hadronic matter generated in high
energy nuclear collisions are discussed.


title:
Basics of Feature Selection and Statistical Learning for High Energy
  Physics

abstract:
  This document introduces basics in data preparation, feature selection and
learning basics for high energy physics tasks. The emphasis is on feature
selection by principal component analysis, information gain and significance
measures for features. As examples for basic statistical learning algorithms,
the maximum a posteriori and maximum likelihood classifiers are shown.
Furthermore, a simple rule based classification as a means for automated cut
finding is introduced. Finally two toolboxes for the application of statistical
learning techniques are introduced.


title: Support Vector Machines in High Energy Physics

abstract:
  This lecture will introduce the Support Vector algorithms for classification
and regression. They are an application of the so called kernel trick, which
allows the extension of a certain class of linear algorithms to the non linear
case. The kernel trick will be introduced and in the context of structural risk
minimization, large margin algorithms for classification and regression will be
presented. Current applications in high energy physics will be discussed.


title: On H.Weyl and J.Steiner polynomials

abstract:
  The paper deals with root problems for two classes of univariate polynomials
both of geometric origin.
  The first class discussed, the class of Steiner polynomial, consists of
polynomials, each associated with a compact convex set V in R^n. A polynomial
of this class describes the volume of the set V+tB^n as a function of t, where
t is a positive number and B^n denotes the unit ball in R. The second class,
the class of Weyl polynomials, consists of polynomials, each associated with a
Riemannian manifold M, where M} is isometrically embedded with positive
codimension in R^n. A Weyl polynomial describes the volume of a tubular
neighborhood of its associated M as a function of the tube's radius. These
polynomials are calculated explicitly in a number of natural examples such as
balls, cubes, squeezed cylinders. Furthermore, we examine how the above
mentioned polynomials are related to one another and how they depend on the
standard embedding of R^n into R^m for m>n. We find that in some cases the real
part of any Steiner polynomial root will be negative. In certain other cases, a
Steiner polynomial will have only real negative roots. In all of this cases, it
can be shown that all of a Weyl polynomial's roots are simple and, furthermore,
that they lie on the imaginary axis. At the same time, in certain cases the
above pattern does not hold.


title: The Many Uses of Chiral Effective Theories

abstract:
  I review basic concepts of chiral effective field theories guided by an
historical perspective: from the first ideas to the merging with other
effective frameworks, and to the interplay with lattice field theory. The
impact of recent theoretical developments on phenomenological predictions is
reviewed with attention for rare decays, and charm physics. I conclude with a
critical look at future applications.


title: Binary Black Hole Coalescence in Semi-Analytic Puncture Evolution

abstract:
  Binary black-hole coalescence is treated semi-analytically by a novel
approach. Our prescription employs the conservative Skeleton Hamiltonian that
describes orbiting Brill-Lindquist wormholes (termed punctures in Numerical
Relativity) within a waveless truncation to the Einstein field equations [G.
Faye, P. Jaranowski and G. Sch\"afer, Phys. Rev. D {\bf 69}, 124029 (2004)]. We
incorporate, in a transparent Hamiltonian way and in Burke-Thorne gauge
structure, the effects of gravitational radiation reaction into the above
Skeleton dynamics with the help of 3.5PN accurate angular momentum flux for
compact binaries in quasi-circular orbits to obtain a Semi-Analytic Puncture
Evolution to model merging black-hole binaries. With the help of the TaylorT4
approximant at 3.5PN order, we perform a {\it first-order} comparison between
gravitational wave phase evolutions in Numerical Relativity and our approach
for equal-mass binary black holes. This comparison reveals that a modified
Skeletonian reactive dynamics that employs flexible parameters will be required
to prevent the dephasing between our scheme and Numerical Relativity, similar
to what is pursued in the Effective One Body approach. A rough estimate for the
gravitational waveform associated with the binary black-hole coalescence in our
approach is also provided.


title: Ultra-cold WIMPs: relics of non-standard pre-BBN cosmologies

abstract:
  Weakly interacting massive particles (WIMPs) are one of very few probes of
cosmology before Big Bang nucleosynthesis (BBN). We point out that in scenarios
in which the Universe evolves in a non-standard manner during and after WIMP
kinetic decoupling, the horizon mass scale at decoupling can be smaller and the
dark matter WIMPs can be colder than in standard cosmology. This would lead to
much smaller first objects in hierarchical structure formation. In low
reheating temperature scenarios the effect may be large enough as to noticeably
enhance indirect detection signals in GLAST and other detectors, by up to two
orders of magnitude.


title: Testing CPT Symmetry with CMB Measurements: Update after WMAP5

abstract:
  In this Letter we update our previous result on the test of CPT symmetry with
Cosmic Microwave Background (CMB) measurements. A CPT violating interaction in
the photon sector ${\cal L}_{cs} \sim p_{\mu}A_{\nu}\tilde F^{\mu\nu}$ gives
rise to a rotation of the polarization vectors of the propagating CMB photons.
Recently the WMAP group used the newly released polarization data of WMAP5 to
measure this rotation angle $\Delta\alpha$ and obtained
$\Delta\alpha=-1.7\pm2.1$ deg ($1\sigma$). However, in their analysis the
BOOMERanG 2003 data is not included. Here we revisit this issue by combining
the full data of WMAP5 and BOOMERanG 2003 angular power spectra for the
measurement of this rotation angle $\Delta\alpha$ and find that
$\Delta\alpha=-2.6\pm1.9$ deg at a 68% confidence level.


title: Classical metric Diophantine approximation revisited

abstract:
  The idea of using measure theoretic concepts to investigate the size of
number theoretic sets, originating with E. Borel, has been used for nearly a
century. It has led to the development of the theory of metrical Diophantine
approximation, a branch of Number Theory which draws on a rich and broad
variety of mathematics. We discuss some recent progress and open problems
concerning this classical theory. In particular, generalisations of the
Duffin-Schaeffer and Catlin conjectures are formulated and explored.


title: Dynamics of delay-coupled excitable neural systems

abstract:
  We study the nonlinear dynamics of two delay-coupled neural systems each
modelled by excitable dynamics of FitzHugh-Nagumo type and demonstrate that
bistability between the stable fixed point and limit cycle oscillations occurs
for sufficiently large delay times and coupling strength. As the mechanism for
these delay-induced oscillations we identify a saddle-node bifurcation of limit
cycles.


title: Hybrid moments of the Riemann zeta-function

abstract:
  The "hybrid" moments $$
\int_T^{2T}|\zeta(1/2+it)|^k{(\int_{t-G}^{t+G}|\zeta(1/2+ix)|^\ell dx)}^m dt $$
of the Riemann zeta-function $\zeta(s)$ on the critical line $\Re s = 1/2$ are
studied. The expected upper bound for the above expression is
$O_\epsilon(T^{1+\epsilon}G^m)$. This is shown to be true for certain specific
values of the natural numbers $k,\ell,m$, and the explicitly determined range
of $G = G(T;k,\ell,m)$. The application to a mean square bound for the Mellin
transform function of $|\zeta(1/2+ix)|^4$ is given.


title: Weakly non-ergodic Statistical Physics

abstract:
  We find a general formula for the distribution of time averaged observables
for weakly non-ergodic systems. Such type of ergodicity breaking is known to
describe certain systems which exhibit anomalous fluctuations, e.g. blinking
quantum dots and the sub-diffusive continuous time random walk model. When the
fluctuations become normal we recover usual ergodic statistical mechanics.
Examples of a particle undergoing fractional dynamics in a binding force field
are worked out in detail. We briefly discuss possible physical applications in
single particle experiments.


title: A note on zero-one laws in metrical Diophantine approximation

abstract:
  In this paper we discuss a general problem on metrical Diophantine
approximation associated with a system of linear forms. The main result is a
zero-one law that extends one-dimensional results of Cassels and Gallagher. The
paper contains a discussion on possible generalisations including a selection
of various open problems.


title: Limit stable objects on Calabi-Yau 3-folds

abstract:
  In this paper, we introduce new enumerative invariants of curves on
Calabi-Yau 3-folds via certain stable objects in the derived category of
coherent sheaves. We introduce the notion of limit stability on the category of
perverse coherent sheaves, a subcategory in the derived category, and construct
the moduli spaces of limit stable objects. We then define the counting
invariants of limit stable objects using Behrend's constructible functions on
that moduli spaces. It will turn out that our invariants are generalizations of
counting invariants of stable pairs introduced by Pandharipande and Thomas. We
will also investigate the wall-crossing phenomena of our invariants under
change of stability conditions.


title: Field theory conjecture for loop-erased random walks

abstract:
  We give evidence that the functional renormalization group (FRG), developed
to study disordered systems, may provide a field theoretic description for the
loop-erased random walk (LERW), allowing to compute its fractal dimension in a
systematic expansion in epsilon=4-d. Up to two loop, the FRG agrees with
rigorous bounds, correctly reproduces the leading logarithmic corrections at
the upper critical dimension d=4, and compares well with numerical studies. We
obtain the universal subleading logarithmic correction in d=4, which can be
used as a further test of the conjecture.


title: Slow Light in Artificial Hybrid Molecules

abstract:
  The optical properties of hybrid molecules composed of semiconductor and
metal nanoparticles with a weak probe in a strong pump field are investigated
theoretically. Excitons in such a hybrid molecule demonstrate novel optical
properties due to the coupling between exciton and plasmon. It is shown that a
non-absorption hole induced by coherent population oscillation appears at the
absorption spectrum of the probe field and there exists slow light effect
resulting in the great change of the refractive index. The numerical results
indicate that with the different center-to-center distance between the two
nanopaticles the slow light effects are greatly modified in terms of
exciton-plasmon couplings.


title: Simulation of partial entanglement with nonsignaling resources

abstract:
  With the goal of gaining a deeper understanding of quantum non-locality, we
decompose quantum correlations into more elementary non-local correlations. We
show that the correlations of all pure entangled states of two qubits can be
simulated without communication, hence using only non-signaling resources. Our
simulation model works in two steps. First, we decompose the quantum
correlations into a local and a non-local part. Second, we present a model for
simulating the nonlocal part using only non-signaling resources. In our model
partially entangled states require more nonlocal resources than maximally
entangled states, but the less the state is entangled, the less frequently must
the nonlocal resources be used.


title: Dark matter direct detection rate in a generic model with micrOMEGAs2.2

abstract:
  We present a new module of the micrOMEGAs package for the calculation of
WIMP-nuclei elastic scattering cross sections relevant for the direct detection
of dark matter through its interaction with nuclei in a large detector. With
this new module, the computation of the direct detection rate is performed
automatically for a generic model of new physics which contains a WIMP
candidate. This model needs to be implemented within micrOMEGAs2.1.


title: An Introduction to Topos Physics

abstract:
  The basic notion of how topoi can be utilized in physics is presented here.
Topos and category theory serve as valuable tools which extend our ordinary
set-theoretical conceptions, can further the study of quantum logic and give
rise to new and 'neo-realistic' descriptions of quantum physics, i.e. make
possible the construction of a general scheme for quantum physics, which 'looks
like' the classical one. A novel way of writing theories of physics, by
representing a formal language of a physical system, into an appropriate topos,
is analyzed here.
  This novel approach is initiated by C.J. Isham and A. Doering and the major
part of this paper comes from there; however there has been an effort in
simplifying the basic ideas and do this work accessible to 'less experts' of
the field. A minor, but not less important, part of this paper is devoted to
resuming, in a concise way the background knowledge of logic, quantum logic and
category theory, that is necessary for anyone who wishes to follow the whole
topos approach.


title:
Failure of feedback as a putative common mechanism of spreading
  depolarizations in migraine and stroke

abstract:
  The stability of cortical function depends critically on proper regulation.
Under conditions of migraine and stroke a breakdown of transmembrane chemical
gradients can spread through cortical tissue. A concomitant component of this
emergent spatio-temporal pattern is a depolarization of cells detected as slow
voltage variations. The velocity of ~3 mm/min indicates a contribution of
diffusion. We propose a mechanism for spreading depolarizations (SD) that rests
upon a nonlocal or non-instantaneous feedback in a reaction-diffusion system.
Depending upon the characteristic space and time scales of the feedback, the
propagation of cortical SD can be suppressed by shifting the bifurcation line,
which separates the parameter regime of pulse propagation from the regime where
a local disturbance dies out. The optimisation of this feedback is elaborated
for different control schemes and ranges of control parameters.


title: lambda-Connectedness Determination for Image Segmentation

abstract:
  Image segmentation is to separate an image into distinct homogeneous regions
belonging to different objects. It is an essential step in image analysis and
computer vision. This paper compares some segmentation technologies and
attempts to find an automated way to better determine the parameters for image
segmentation, especially the connectivity value of $\lambda$ in
$\lambda$-connected segmentation.
  Based on the theories on the maximum entropy method and Otsu's minimum
variance method, we propose:(1)maximum entropy connectedness determination: a
method that uses maximum entropy to determine the best $\lambda$ value in
$\lambda$-connected segmentation, and (2) minimum variance connectedness
determination: a method that uses the principle of minimum variance to
determine $\lambda$ value. Applying these optimization techniques in real
images, the experimental results have shown great promise in the development of
the new methods. In the end, we extend the above method to more general case in
order to compare it with the famous Mumford-Shah method that uses variational
principle and geometric measure.


title: Some operator monotone functions

abstract:
  We prove that the functions t -> (t^q-1)(t^p-1)^{-1} are operator monotone in
the positive half-axis for 0 < p < q < 1, and we calculate the two associated
canonical representation formulae. The result is used to find new monotone
metrics (quantum Fisher information) on the state space of quantum systems.


title: SAFIUS - A secure and accountable filesystem over untrusted storage

abstract:
  We describe SAFIUS, a secure accountable file system that resides over an
untrusted storage. SAFIUS provides strong security guarantees like
confidentiality, integrity, prevention from rollback attacks, and
accountability. SAFIUS also enables read/write sharing of data and provides the
standard UNIX-like interface for applications. To achieve accountability with
good performance, it uses asynchronous signatures; to reduce the space required
for storing these signatures, a novel signature pruning mechanism is used.
SAFIUS has been implemented on a GNU/Linux based system modifying OpenGFS.
Preliminary performance studies show that SAFIUS has a tolerable overhead for
providing secure storage: while it has an overhead of about 50% of OpenGFS in
data intensive workloads (due to the overhead of performing
encryption/decryption in software), it is comparable (or better in some cases)
to OpenGFS in metadata intensive workloads.


title:
Arithmetic Riemann-Roch and Hilbert-Samuel formulae for pointed stable
  curves

abstract:
  We prove arithmetic Riemann-Roch and Hilbert-Samuel type formulae for pointed
stable curves. We give applications to volumes of lattices of integral cusps
forms for pointed stable curves of genus 0.


title:
Evidence for a Transverse Single-Spin Asymmetry in Leptoproduction of
  pi+pi- Pairs

abstract:
  A single-spin asymmetry was measured in the azimuthal distribution of pi+pi-
pairs produced in semi-inclusive deep-inelastic scattering on a transversely
polarized hydrogen target. For the first time, evidence is found for a
correlation between the transverse target polarization and the azimuthal
orientation of the plane containing the two pions.The corresponding single-spin
asymmetry is expected to be related to the product of the little-known quark
transversity distribution function and an unknown naive-T-odd chiral-odd
dihadron fragmentation function.


title: Methods and Models for Hadron Physics

abstract:
  A round table held during the Hadron07 Conference focusing on experimental
observations of new hadronic states, on theoretical perspectives for their
description, and on the role of hadronic spectroscopy in furthering our
knowledge of the fundamental theory of strong interactions.


title: Cl\^oture int\'egrale des id\'eaux et \'equisingularit\'e

abstract:
  This text has two parts; the first is the essentially unmodified text of the
1973-74 seminar of M. Lejeune-Jalabert and B. Teissier on integral dependence
in complex analytic geometry with J-J. Risler's appendix on the Lojasiewicz
exponents in the real analytic framework. The second part consists of seven
complements written in 2007 surveying recent results directly connected to the
content of the seminar. The main results of the first part concern the
asymptotic order function with respect to an ideal and in particular its
connection with the Lojasiewicz exponent. Another aspect concerns the
finiteness properties of the graded algebra associated with the filtration by
the asymptotic order function.


title:
IMAGES II. A surprisingly low fraction of undisturbed rotating spiral
  disks at z~0.6: The morpho-kinematical relation 6 Gyrs ago

abstract:
  We present a first combined analysis of the morphological and dynamical
properties for the Intermediate MAss Galaxy Evolution Sequence (IMAGES) sample.
It is a representative sample of 52 z~0.6 galaxies with Mstell from 1.5 to 15
10^10Msun and possessing 3D resolved kinematics and HST deep imaging in at
least two broad band filters. We aim at evaluate robustly the evolution of
rotating spirals since z~0.6, as well as to test the different schemes for
classifying galaxies morphologically. We used all the information provided by
multi-band images, color maps and 2 dimensional light fitting to assign to each
object a morphological class. We divided our sample between spiral disks,
peculiar objects, compact objects and mergers. Using our morphological
classification scheme, 4/5 of identified spirals are rotating disks and more
than 4/5 of identified peculiar galaxies show complex kinematics, while
automatic classification methods such as Concentration-Asymmetry and GINI-M20
severely overestimate the fraction of relaxed disk galaxies. Using this
methodology, we find that the fraction of rotating spirals has increased by a
factor ~ 2 during the last 6 Gyrs, a much higher fraction that found previously
based on morphologies alone. These rotating spiral disks are forming stars very
rapidly, doubling their stellar masses over the last 6 Gyrs, while most of
their stars have been formed few Gyrs earlier, which reveals the presence of a
large gas supply. Because they are likely the progenitors of local spirals, we
can conjecture how their properties are evolving. Their disks show some
evidence for an inside-out growth and the gas supply/accretion is not made
randomly as the disk need to be stable in order to match the local disk
properties.


title: Structured matrices and inverses

abstract:
  A matrix (and any associated linear system) will be referred to as structured
if it has a small displacement rank. It is known that the inverse of a
structured matrix is structured, which allows fast inversion (or solution), and
reduced storage requirements. According to two definitions of displacement
structure of practical interest, it is shown here that several types of
inverses are also structured, including the Moore-Penrose inverse of
rank-deficient matrices.


title: Excited Quark Production at Future $\gamma p$ Colliders

abstract:
  Excited quark production at future $\gamma p$ colliders is studied. Namely,
$\gamma p \to q^{*}X$ with subsequent $q^{*}\to gq$ and $\gamma q $ decay
channels are considered. Signatures for discovery of the excited quark and
corresponding standard model backgrounds are discussed in detail. Discovery
limits for excited quark masses and achievable values of compositeness
parameters $f_s$, $f$ and $f^\prime $ are determined.


title:
A convergence analysis of the iteratively regularized Gauss-Newton
  method under Lipschitz condition

abstract:
  In this paper we consider the iteratively regularized Gauss-Newton method for
solving nonlinear ill-posed inverse problems. Under merely Lipschitz condition,
we prove that this method together with an a posteriori stopping rule defines
an order optimal regularization method if the solution is regular in some
suitable sense.


title: Limits of groupoid C*-algebras arising from open covers

abstract:
  I. Raeburn and J. Taylor have constructed continuous-trace C*-algebras with a
prescribed Dixmier-Douady class, which also depend on the choice of an open
cover of the spectrum. We study the asymptotic behavior of these algebras with
respect to certain refinements of the cover and appropriate extension of
cocycles. This leads to the analysis of a limit groupoid G and a cocycle
\sigma, and the algebra C*(G, \sigma) may be regarded as a generalized direct
limit of the Raeburn-Taylor algebras. As a special case, all UHF C*-algebras
arise from this limit construction.


title: Unavoidable patterns

abstract:
  Let \mathcal{F}_k denote the family of 2-edge-colored complete graphs on 2k
vertices in which one color forms either a clique of order k or two disjoint
cliques of order k. Bollob\'as conjectured that for every \epsilon>0 and
positive integer k there is an n(k,\epsilon) such that every 2-edge-coloring of
the complete graph of order n \geq n(k,\epsilon) which has at least \epsilon {n
\choose 2} edges in each color contains a member of \mathcal{F}_k. This
conjecture was proved by Cutler and Mont\'agh, who showed that
n(k,\epsilon)<4^{k/\epsilon}. We give a much simpler proof of this conjecture
which in addition shows that n(k,\epsilon)<\epsilon^{-ck} for some constant c.
This bound is tight up to the constant factor in the exponent for all k and
\epsilon. We also discuss similar results for tournaments and hypergraphs.


title: Dirac generating operators and Manin triples

abstract:
  Given a pair of (real or complex) Lie algebroid structures on a vector bundle
$A$ (over $M$) and its dual $A^*$, and a line bundle $\module$ such that
$\module\otimes\module=(\wedge^{\TOP} A^*\otimes\wedge^{\TOP} T^*M)$, there
exist two canonically defined differential operators $\bdees$ and $\bdel$ on
$\sections{\wedge A\otimes\module}$. We prove that the pair $(A,A^*)$
constitutes a Lie bialgebroid if, and only if, the square of $\bdirac
=\bdees+\bdel$ is the multiplication by a function on $M$. As a consequence, we
obtain that the pair $(A,A^*)$ is a Lie bialgebroid if, and only if, $\bdirac$
is a Dirac generating operator as defined by Alekseev & Xu \cite{AlekseevXu}.
Our approach is to establish a list of new identities relating the Lie
algebroid structures on $A$ and $A^*$ (Theorem \ref{Thm:C}).


title:
A Simple Operator Check of the Effective Fermion Mode Function during
  Inflation

abstract:
  We present a relatively simple operator formalism which reproduces the
leading infrared logarithm of the one loop quantum gravitational correction to
the fermion mode function on a locally de Sitter background. This rule may
serve as the basis for an eventual stochastic formulation of quantum gravity
during inflation. Such a formalism would not only effect a vast simplification
in obtaining the leading powers of $\ln(a)$ at fixed loop orders, it would also
permit us to sum the series of leading logarithms. A potentially important
point is that our rule does not seem to be consistent with any simple infrared
truncation of the fields. Our analysis also highlights the importance of spin
as a gravitational interaction that persists even when kinetic energy has
redshifted to zero.


title:
Pseudochaotic poloidal transport in the laminar regime of the resistive
  ballooning instabilities

abstract:
  In toroidal geometry, and prior to the establishment of a fully developed
turbulent state, the so-called topological instability of the
pressure-gradient-driven turbulence is observed. In this intermediate state, a
narrow spectral band of modes dominates the dynamics, giving rise to the
formation of iso-surfaces of electric potential with a complicated topology.
Since E x B advection of tracer particles takes place along these iso-surfaces,
their topological complexity affects the characteristic features of radial and
poloidal transport dramatically. In particular, they both become strongly
non-diffusive and non-Gaussian. Since radial transport determines the system
confinement properties and poloidal transport controls the equilibration
dynamics (on any magnetic surface), the development of non-diffusive models in
both directions is thus of physical interest. In previous work, a fractional
model to describe radial transport was constructed by the authors. In this
contribution, recent results on periodic fractional models are exploited for
the construction of an effective model of poloidal transport. Numerical
computations using a three-dimensional reduced magnetohydrodynamic set of
equations are compared with analytical solutions of the fractional periodic
model. It is shown that the aforementioned analytical solutions accurately
describe poloidal transport, which turns out to be superdiffusive with index
$\alpha=1$.


title: Effective computation of knot Floer homology

abstract:
  We extend an approach of Beliakova for computing knot Floer homology and
implement it in a publicly available computer program. We review the main
programming and optimization methods used. Our program is then used to check
that the Floer homology of a prime non-alternating knot with less than 12
crossings has no torsion.


title:
Millisecond microwave spikes: statistical study and application for
  plasma diagnostics

abstract:
  We analyze a dense cluster of solar radio spikes registered at ~ 4.5 -- 6 GHz
by the Purple Mountain Observatory spectrometer (Nanjing, China) operating in
the 4.5 -- 7.5 GHz range with the 5 ms temporal resolution. To handle with the
data from the spectrometer we developed a new technique utilizing a nonlinear
multi-Gaussian spectral fit based on chi-squared criteria to extract individual
spikes from the originally recorded spectra. Applying this method to the
experimental raw data we eventually identified about 3000 spikes for this
event, which allows for a detailed statistical analysis. Various statistical
characteristics of the spikes have been evaluated, including intensity
distributions, spectral bandwidth distributions, and distribution of the spike
mean frequencies. The most striking finding of this analysis is distributions
of the spike bandwidth, which are remarkably asymmetric. To reveal the
underlaying microphysics we explore the local trap model with the renormalized
theory of spectral profile of the electron cyclotron maser (ECM) emission peak
in a source with random magnetic irregularities. The distribution of the solar
spikes relative bandwidth calculated within the local trap model represents an
excellent fit to the experimental data. Accordingly, the developed technique
may offer a new tool of studying very low levels of the magnetic turbulence in
the spike sources, when the ECM mechanism of the spike cluster is confirmed.


title: Class field theory for curves over $p$-adic fields

abstract:
  We develop class field theory of curves over $p$-adic fields which extends
the unramified theory of S. Saito. The class groups which approximate abelian
\'etale fundamental groups of such curves are introduced in the terms of
algebraic $K$-groups by imitating G. Wiesend's class group for curves over
finite fields.


title:
Comment on "Using Three-Body Recombination to Extract Electron
  Temperatures of Ultracold Plasmas"

abstract:
  In the recent work Fletcher et al. [Phys. Rev. Lett., v.99, p.145001 (2007)]
reported on the novel experimental technique, enabling to measure the
temperature of the expanding ultracold plasmas over a considerable time
interval (up to 60-70 {\mu}s). It was unexpectedly found that the electron
temperature dropped with time as T_e(t) ~ t^{-\alpha} with \alpha = 1.2 +/- 0.1
\approx 1 instead of \alpha = 2, which would be expected for the adiabatic
cooling of electrons in the cloud expanding linearly in time. The above-cited
authors supposed that 'the difference is likely due to the significant heating
effects from 3-body recombination' (i.e. the inelastic processes), but they did
not provide sufficient quantitative estimates supporting such a conclusion. The
aim of the present comment is to mention that the experimentally revealed
t^{-1}-dependence can be explained under quite general assumptions by the
purely elastic processes in the ultracold plasma, as it was done a few years
ago in our work [Yu.V. Dumin, J. Low Temp. Phys., v.119, p.377 (2000)].
  Therefore, t^{-1}-dependence revealed in the above-cited experiment should be
primarily a manifestation of "virialization" of the electron velocities in the
regime of strong electron-ion correlations, while the heat release by inelastic
processes should be of secondary importance (it might be responsible,
particularly, for changing the exponent from -1 to -1.2). This is confirmed
also by our ab initio molecular-dynamic simulations taking into account the
strong electron-ion correlations (i.e. not based on the PIC method, Vlasov
approximation for electrons, etc., which are applicable only to small-angular
scattering).


title: Conservation Laws in Generalized Riemann-Silberstein Electrodynamics

abstract:
  Starting from positive and negative helicity Maxwell equations expressed in
Riemann-Silberstein vectors, we derive the ten usual and ten additional
Poincar{\'e} invariants, the latter being related to the electromagnetic spin,
i.e., the intrinsic rotation, or state of polarization, of the electromagnetic
fields. Some of these invariants have apparently not been discussed in the
literature before.


title:
Frequency Correlation of QPOs Based on a Resonantly-Excited
  Disk-Oscillation Model

abstract:
  In previous papers, we have proposed a model that the high-frequency
quasi-periodic oscillations (HF QPOs) observed in black-hole and neutron-star
X-ray binaries are inertial-acoustic oscillations that are resonantly excited
on a one-armed deformed disk by nonlinear couplings between the oscillations
and the disk deformation. In this paper we show that in addition to the
inertial-acoustic waves, one-armed corrugation waves are also excited in the
deformed disks. They are low-frequency oscillations. We examine frequencies and
their correlations among the inertial-acoustic oscillations and the corrugation
waves that are excited, in order to know whether they can describe observed
frequency correlations among kHz QPOs and low-frequency QPOs (LF QPOs) in
neutron-star X-ray binaries. The results seem to well describe the observed
correlations in Cir X-1, if we adopt $M= 1.5\sim 2.0 M_\odot$ and $a_* \sim
0.8$, where $M$ is the mass of the central star and $a_*$ is the dimensionless
spin parameter of the metric. Finally, assumptions involved in this
disk-oscillation model are briefly summarized and discussed.


title:
Flavor symmetry and decays of charmed mesons to pairs of light
  pseudoscalars

abstract:
  New data on the decays of the charmed particles $D^0$, $D^+$, and $D_s$ to
pairs of light pseudoscalar mesons $P$ allow the testing of flavor symmetry and
the extraction of key amplitudes. Information on relative strong phases is
obtained. One sees evidence for the expected interference between
Cabibbo-favored and doubly-Cabibbo-suppressed decays in the differing patterns
of $D^0 \to K_{S,L} \pi^0$ and $D^+ \to K_{S,L} \pi^+$ decays.


title:
Conformal Computing: Algebraically connecting the hardware/software
  boundary using a uniform approach to high-performance computation for
  software and hardware applications

abstract:
  We present a systematic, algebraically based, design methodology for
efficient implementation of computer programs optimized over multiple levels of
the processor/memory and network hierarchy. Using a common formalism to
describe the problem and the partitioning of data over processors and memory
levels allows one to mathematically prove the efficiency and correctness of a
given algorithm as measured in terms of a set of metrics (such as
processor/network speeds, etc.). The approach allows the average programmer to
achieve high-level optimizations similar to those used by compiler writers
(e.g. the notion of "tiling").
  The approach presented in this monograph makes use of A Mathematics of Arrays
(MoA, Mullin 1988) and an indexing calculus (i.e. the psi-calculus) to enable
the programmer to develop algorithms using high-level compiler-like
optimizations through the ability to algebraically compose and reduce sequences
of array operations. Extensive discussion and benchmark results are presented
for the Fast Fourier Transform and other important algorithms.


title: Generation of two-mode entanglement between separated cavities

abstract:
  We propose a scheme for the generation of two-mode entangled states between
two spatially separated cavities. It utilizes a two-level atom sequentially
coupling to two high-Q cavities with a strong classical driving field. It is
shown that by suitably choosing the intensities and detunings of the fields and
coherent control of the dynamics, several different entangled states such as
entangled coherent states and Bell states can be produced between the modes of
the two cavities.


title: Quantitative analysis of privatization

abstract:
  In recent years, the economic policy of privatization, which is defined as
the transfer of property or responsibility from public sector to private
sector, is one of the global phenomenon that increases use of markets to
allocate resources. One important motivation for privatization is to help
develop factor and product markets, as well as security markets. Progress in
privatization is correlated with improvements in perceived political and
investment risk. Many emerging countries have gradually reduced their political
risks during the course of sustained privatization. In fact, most risk
resolution seems to take place as privatization proceeds to its later stage.
Alternative benefits of privatization are improved risk sharing and increased
liquidity and activity of the market. One of the main methods to develop
privatization is entering a new stock to the markets for arising competition.
However, attention to the capability of the markets to accept a new stock is
substantial. Without considering the above statement, it is possible to reduce
the market's efficiency. In other words, introduction of a new stock to the
market usually decreases the stage of development and activity and increases
the risk. Based on complexity theory, we quantify how the following factors:
stage of development, activity, risk and investment horizons play roles in the
privatization.


title:
Absolute continuity and convergence in variation for distributions of
  functionals of Poisson point measure

abstract:
  General sufficient conditions are given for absolute continuity and
convergence in variation of the distributions of the unctionals on a
probability space, generated by a Poisson point measure. The phase space of the
Poisson point measure is supposed to be of the form (0,\infty)\times U, and its
intensity measure to be equal dt\Pi(du). We introduce the family of time
stretching transformations of the configurations of the point measure. The
sufficient conditions for absolute continuity and convergence in variation are
given in the terms of the time stretching transformations and the relative
differential operators. These conditions are applied to solutions of SDE's
driven by Poisson point measures, including an SDE's with non-constant jump
rate.


title: Persistent spin currents in electron systems with spin-orbit interaction

abstract:
  We investigate the persistent spin currents in one- and two-dimensional
electron systems with spin-orbit interaction in thermodynamics equilibrium at
absolute zero temperature. The persistent spin current is the intrinsic one
which is connected with the Berry phases in the configuration spaces of an
electron system and winding numbers in the field configurations of electrons.
When the topological space of the configuration of a system has the nontrivial
first homotopy groups, the persistent spin currents in the system could be
nonzero and not easily destroyed by impurity scattering in ballistic limit. The
non-vanishing background spin currents in infinite two-dimensional electron
system found by Rashba could be realized by the transport persistent spin
currents in a finite torus electron system with spin-orbit interaction. In this
sense, we meet the challenge proposed by Rashba.


title: Orbits of s-representations with degenerate Gauss mappings

abstract:
  In this paper we study tangentially degeneracy of the orbits of
s-representations in the sphere. We show that an orbit of an s-representation
is tangentially degenerate if and only if it is through a long root, or a short
root of restricted root system of type G_2. Moreover these orbits provide many
new examples of tangentially degenerate submanifolds which satisfy the Ferus
equality.


title: CoSaMP: Iterative signal recovery from incomplete and inaccurate samples

abstract:
  Compressive sampling offers a new paradigm for acquiring signals that are
compressible with respect to an orthonormal basis. The major algorithmic
challenge in compressive sampling is to approximate a compressible signal from
noisy samples. This paper describes a new iterative recovery algorithm called
CoSaMP that delivers the same guarantees as the best optimization-based
approaches. Moreover, this algorithm offers rigorous bounds on computational
cost and storage. It is likely to be extremely efficient for practical problems
because it requires only matrix-vector multiplies with the sampling matrix. For
many cases of interest, the running time is just O(N*log^2(N)), where N is the
length of the signal.


title:
Neutrino Mass Bounds from Neutrinoless Double Beta Decays and Large
  Scale Structures

abstract:
  We investigate the way how the total mass sum of neutrinos can be constrained
from the neutrinoless double beta decay and cosmological probes with cosmic
microwave background (WMAP 3-year results), large scale structures including
2dFGRS and SDSS data sets. First we discuss, in brief, on the current status of
neutrino mass bounds from neutrino beta decays and cosmic constrain within the
flat $\Lambda CMD$ model. In addition, we explore the interacting neutrino
dark-energy model, where the evolution of neutrino masses is determined by
quintessence scalar filed, which is responsable for cosmic acceleration today.
Assuming the flatness of the universe, the constraint we can derive from the
current observation is $\sum m_{\nu} < 0.87$eV at the 95 % confidence level,
which is consistent with $\sum m_{\nu} < 0.68$eV in the flat $\Lambda CDM$
model. Finally we discuss the future prospect of the neutrino mass bound with
weak-lensing effects.


title: The adjusted Viterbi training for hidden Markov models

abstract:
  The EM procedure is a principal tool for parameter estimation in the hidden
Markov models. However, applications replace EM by Viterbi extraction, or
training (VT). VT is computationally less intensive, more stable and has more
of an intuitive appeal, but VT estimation is biased and does not satisfy the
following fixed point property. Hypothetically, given an infinitely large
sample and initialized to the true parameters, VT will generally move away from
the initial values. We propose adjusted Viterbi training (VA), a new method to
restore the fixed point property and thus alleviate the overall imprecision of
the VT estimators, while preserving the computational advantages of the
baseline VT algorithm. Simulations elsewhere have shown that VA appreciably
improves the precision of estimation in both the special case of mixture models
and more general HMMs. However, being entirely analytic, the VA correction
relies on infinite Viterbi alignments and associated limiting probability
distributions. While explicit in the mixture case, the existence of these
limiting measures is not obvious for more general HMMs. This paper proves that
under certain mild conditions, the required limiting distributions for general
HMMs do exist.


title:
RAId DbS: A Mass-Spectrometry Based Peptide Identification Web Server
  with Knowledge Integration

abstract:
  Summary: In anticipation of the individualized proteomics era and the need to
integrate knowledge from disease studies, we have augmented our peptide
identification software RAId DbS to take into account annotated single amino
acid polymorphisms, post-translational modifications, and their documented
disease associations while analyzing a tandem mass spectrum. To facilitate new
discoveries, RAId DbS allows users to conduct searches permitting novel
polymorphisms. Availability: The webserver link is http://www.ncbi.nlm.nih.gov/
/CBBResearch/qmbp/raid dbs/index.html. The relevant databases and binaries of
RAId DbS for Linux, Windows, and Mac OS X are available from the same web page.
Contact: yyu@ncbi.nlm.nih.gov


title:
On Connection between the Numbers of Permutations and Full Cycles with
  Some Restrictions on Positions and Up-Down Structure

abstract:
  We discuss both simple and more subtle connections between the numbers of
permutations and full cycles with some restrictions,in particular, between the
numbers of permutations and full cycles with prescribed up-down structure.


title:
On the Detection of High Redshift Black Holes with ALMA through CO and
  H2 Emission

abstract:
  Many present-day galaxies are known to harbor supermassive, >10^6 Mo, black
holes. These central black holes must have grown through accretion from less
massive seeds in the early universe. The molecules CO and H2 can be used to
trace this young population of accreting massive black holes through the X-ray
irradiation of ambient gas. The X-rays drive a low-metallicity ion-molecule
chemistry that leads to the formation and excitation of CO and H2 in
100<T<1,000 K gas. H2 traces very low metallicity gas, ~10^-3 solar or less,
while some pollution by metals, ~10^-2 solar or more, must have taken place to
form CO. Strong CO J>15 and H2 S(0) & S(1) emission is found that allows one to
constrain ambient conditions. Comparable line strengths cannot be produced by
FUV or cosmic ray irradiation. Weak, but perhaps detectable, H3+ (2,2) - (1,1)
emission is found and discussed. The models predict that black hole masses
larger than 10^5 Mo can be detected with ALMA, over a redshift range of 5-20,
provided that the black holes radiate close to Eddington.


title:
Crossing of the Phantom Divided Barrier with Lorentz Invariance
  Violating Fields

abstract:
  We study possible crossing of the phantom divided barrier in a Lorentz
invariance violating dark energy model. Lorentz invariance violation which is
achieved by introducing a vector field in the action, incorporates directly in
the dynamics of the scalar field and equation of state. This interesting
feature allows us to study phantom divided barrier crossing in the context of
Lorentz invariance violation. We show that for suitable choice of parameter
space, equation of state can cross phantom divided barrier just by one scalar
field and Lorentz violating vector field controls this crossing.


title:
Some Considerations on Six Degrees of Separation from A Theoretical
  Point of View

abstract:
  In this article we discuss six degrees of separation, which has been proposed
by Milgram, from a theoretical point of view. Simply if one has $k$ friends,
the number $N$ of indirect friends goes up to $\sim k^d$ in $d$ degrees of
separation. So it would easily come up to population of whole world. That,
however, is unacceptable. Mainly because of nonzero clustering coefficient $C$,
$N$ does not become $\sim k^d$. In this article, we first discuss relations
between six degrees of separation and the clustering coefficient in the small
world network proposed by Watt and Strogatz\cite{Watt1},\cite{Watt2}.
Especially, conditions that $(N)>$ (population of U.S.A or of the whole world)
arises in the WS model is explored by theoretical and numerical points of view.
Secondly we introduce an index that represents velocity of propagation to the
number of friends and obtain an analytical formula for it as a function of $C$,
$K$, which is an average degree over all nodes, and some parameter $P$
concerned with network topology. Finally the index is calculated numerically to
study the relation between $C$, $K$ and $P$ and $N$.


title:
Evidence for Ballistic Thermal Conduction in the One-Dimensional S=1/2
  Heisenberg Antiferromagnetic Spin System Sr2CuO3

abstract:
  We have measured the thermal conductivity of the one-dimensional (1D) S=1/2
Heisenberg antiferromagnetic spin system of Sr2Cu1-xPdxO3 single crystals
including nonmagnetic impurities of Pd2+. It has been found that the mean free
path of spinons along the 1D spin chain at low temperatures is very close to
the average length of finite spin chains between spin defects estimated from
the magnetic susceptibility measurements. This proves that the thermal
conduction due to spinons at low temperatures in Sr2CuO3 is ballistic as
theoretically expected [Zotos et al.: Phys. Rev. Lett. 55 (1997) 11029].


title:
Rotation numbers of invariant manifolds around unstable periodic orbits
  for the diamagnetic Kepler problem

abstract:
  In this paper, a method to construct topological template in terms of
symbolic dynamics for the diamagnetic Kepler problem is proposed. To confirm
the topological template, rotation numbers of invariant manifolds around
unstable periodic orbits in a phase space are taken as an object of comparison.
The rotation numbers are determined from the definition and connected with
symbolic sequences encoding the periodic orbits in a reduced Poincar\'e
section. Only symbolic codes with inverse ordering in the forward mapping can
contribute to the rotation of invariant manifolds around the periodic orbits.
By using symbolic ordering, the reduced Poincar\'e section is constricted along
stable manifolds and a topological template, which preserves the ordering of
forward sequences and can be used to extract the rotation numbers, is
established. The rotation numbers computed from the topological template are
the same as those computed from their original definition.


title: A Simple Throw Model for Frontal Vehicle-Pedestrian Collisions

abstract:
  This paper discusses a simple theoretical throw model for frontal
vehicle-pedestrian collisions. The model is based on the simple assumption that
pedestrian movement after impact can be approximated by movement of a mass
point. Two methods of reconstruction of vehicle-pedestrian collision are
discussed: one knowing only the throw distance and the other when also impact
to ground contact distance is known. The model is verified by field data
available in the literature and by comportment with full scale numerical
simulation.
  This paper has been withdrawn by the author due to error in spreadsheet
program which results in misleading results in verification section of the
article.


title: Cavity-resonant excitation for efficient single photon generation

abstract:
  We present an efficiently pumped single photon source based on single quantum
dots (QD) embedded in photonic crystal nanocavities. Resonant excitation of a
QD via a higher order cavity mode results in a 100$\times$ reduced optical
power at the saturation onset of the photoluminescence, compared with
excitation at the same frequency, after the cavity mode is detuned.
Furthermore, we demonstrate that this excitation scheme leads to selective
excitation of QDs coupled to the cavity by comparing photoluminescence and
auto-correlation spectra for the same excitation wavelength with and without
the cavity mode. This provides much cleaner conditions for single photon
generation.


title: Integral field near-infrared spectroscopy of II Zw 40

abstract:
  We present integral field spectroscopy in the near-infrared of the nearby
starburst galaxy IIZw40. Our new observations provide an unprecedented detailed
view of the interstellar medium and star formation of this galaxy. The
radiation emitted by the galaxy is dominated by a giant HII region, which
extends over an area of more than 400 pc in size. A few clusters are present in
this area, however one in particular appears to be the main source of ionizing
photons. We derive the properties of this object and compare them with those of
the 30 Doradus cluster in the Large magellanic cloud (LMC). We study the
spatial distribution and velocity field of different components of the
inetrstellar medium (ISM), mostly through the Bracket series lines, the
molecular hydrogen spectrum, and [FeII]. We find that [FeII] and H2 are mostly
photon excited, but while the region emitting [FeII] is almost coincident with
the giant HII region observed in the lines of atomic H and He, the H2 has a
quite different distribution in space and velocity. The age of the stellar
population in the main cluster is such that no supernova (SN) should be present
yet so that the gas kinematics must be dominated by the young stars. We do not
see, in the starbursting region, any geometrical or dynamical structure that
can be related to the large scale morphology of the galaxy.


title:
Point-Contact Spectroscopy of Iron-Based Layered Superconductor
  LaO$_{0.9}$F$_{0.1-\delta}$FeAs

abstract:
  We present point-contact spectroscopy data for junctions between a normal
metal and the newly discovered F-doped superconductor
LaO$_{0.9}$F$_{0.1-\delta}$FeAs (F-LaOFeAs). A zero-bias conductance peak was
observed and its shape and magnitude suggests the presence of Andreev bound
states at the surface of F-LaOFeAs, which provides a possible evidence of an
unconventional pairing symmetry with a nodal gap function. The maximum gap
value $\Delta_0\approx3.9\pm0.7$meV was determined from the measured spectra,
in good agreement with the recent experiments on specific heat and lower
critical field.


title: Lattice of Triangulations: the proof and an algorithm

abstract:
  In this paper, we prove that the set of triangulations of a polygon can be
equipped with an order to become a lattice. First, we define this order. In
[HN99], authors defined the flip operator and then prove some properties of the
graph of triangulations. We use their theorems and extend them to construct the
lattice of triangulations. We prove this lattice property and introduce an
elegant algorithm which correctness is induced from the proof. The complexity
of this algorithm will be considered. This algorithm is efficient to find the
infimum of a pair of triangulations.


title:
Scale-dependence of transverse momentum correlations in Pb-Au collisions
  at 158A GeV/c

abstract:
  We present results on transverse momentum correlations of charged particle
pairs produced in Pb-Au collisions at 158$A$ GeV/$c$ at the Super Proton
Synchrotron. The transverse momentum correlations have been studied as a
function of collision centrality, angular separation of the particle pairs,
transverse momentum and charge sign. We demonstrate that the results are in
agreement with previous findings in scale-independent analyses at the same beam
energy. Employing the two-particle momentum correlator $<\Delta p_{t,i}, \Delta
p_{t,j}>$ and the cumulative $p_t$ variable $x(p_t)$, we identify, using the
scale-dependent approach presented in this paper, different sources
contributing to the measured correlations, such as quantum and Coulomb
correlations, elliptic flow and mini-jet fragmentation.


title:
Anisotropic spin transport in two-terminal mesoscopic rings: the Rashba
  and Dresselhaus spin-orbit interactions

abstract:
  We investigate theoretically the spin transport in two-terminal mesoscopic
rings in the presence of both the Rashba spin-orbit interaction (RSOI) and the
Dresselhaus spin-orbit interaction (DSOI). We find that the interplay between
the RSOI and DSOI breaks the original cylindric symmetry of mesoscopic ring and
consequently leads to the anisotropic spin transport, i.e., the conductance is
sensitive to the positions of the incoming and outgoing leads. The anisotropic
spin transport can survive even in the presence of disorder caused by impurity
elastic scattering in a realistic system.


title: Quantum Broadening of k-Strings from the AdS/CFT Correspondence

abstract:
  We study the quantum broadening (width) of k-strings. We generalise an old
result by Luscher, Munster and Weisz to the case of a k-string, by using the
gauge/gravity correspondence. When the fundamental QCD-string is replaced by a
bound state of k strings, the bound state is better described by a wrapped
D-brane. We calculate the width of the k-string (the wrapped D-brane) in
several AdS/CFT backgrounds by using a D-brane probe and find universally that
omega_k ^2 = 1 / (2\pi \sigma_k) log R/r .


title: Realistic searches on stretched exponential networks

abstract:
  We consider navigation or search schemes on networks which have a degree
distribution of the form $P(k) \propto \exp(-k^\gamma)$. In addition, the
linking probability is taken to be dependent on social distances and is
governed by a parameter $\lambda$. The searches are realistic in the sense that
not all search chains can be completed. An estimate of $\mu=\rho/s_d$, where
$\rho$ is the success rate and $s_d$ the dynamic path length, shows that for a
network of $N$ nodes, $\mu \propto N^{-\delta}$ in general. Dynamic small world
effect, i.e., $\delta \simeq 0$ is shown to exist in a restricted region of the
$\lambda-\gamma$ plane.


title: Numerical Analysis of Optimized Coherent Control Pulses

abstract:
  Numerically we simulate the effect of optimized coherent control pulses with
a finite duration on a qubit in a bath of spins. The pulses of finite duration
are compared with ideal instantaneous pulses. In particular, we show that
properly designed short pulses can approximate ideal instantaneous pulses up to
a certain order in the shortness of the pulse. We provide examples of such
pulses, quantify the discrepancy from the ideal case and compare their effect
for various ranges of the coupling constants.


title:
Results about persymmetric matrices over F_2 and related exponential
  sums

abstract:
  In this paper we expose our main results about rank problems concerning
persymmetric matrices over F_2 associated to some exponential sums.


title: Fermionic Casimir effect in toroidally compactified de Sitter spacetime

abstract:
  We investigate the fermionic condensate and the vacuum expectation values of
the energy-momentum tensor for a massive spinor field in de Sitter spacetime
with spatial topology $\mathrm{R}^{p}\times (\mathrm{S}^{1})^{q}$. Both cases
of periodicity and antiperiodicity conditions along the compactified dimensions
are considered. By using the Abel-Plana formula, the topological parts are
explicitly extracted from the vacuum expectation values. In this way the
renormalization is reduced to the renormalization procedure in uncompactified
de Sitter spacetime. It is shown that in the uncompactified subspace the
equation of state for the topological part of the energy-momentum tensor is of
the cosmological constant type. Asymptotic behavior of the topological parts in
the expectation values is investigated in the early and late stages of the
cosmological expansion. In the limit when the comoving length of a compactified
dimension is much smaller than the de Sitter curvature radius the topological
part in the expectation value of the energy-momentum tensor coincides with the
corresponding quantity for a massless field and is conformally related to the
corresponding flat spacetime result. In this limit the topological part
dominates the uncompactified de Sitter part. In the opposite limit, for a
massive field the asymptotic behavior of the topological parts is damping
oscillatory for both fermionic condensate and the energy-momentum tensor.


title: String cosmological model in the presence of a magnetic flux

abstract:
  A Bianchi type I string cosmological model in the presence of a magnetic flux
is investigated. A few plausible assumptions regarding the parametrization of
the cosmic string and magneto-fluid are introduced and some exact analytical
solutions are presented.


title: Pushing the detection limit of Magnetic Circular Dichroism to 2 nm

abstract:
  Magnetic Circular Dichroism (MCD) is a standard technique for the study of
magnetic properties of materials in synchrotron beamlines. We present here a
new scattering geometry in the Transmission Electron Microscope through which
MCD can be observed with unprecedented spatial resolution. A convergent
electron beam is used to scan a multilayer Fe/Au sample and record energy loss
spectra. Differences in the spectra induced by the magnetic moments of the Fe
atoms can be resolved with a resolution of 2 nm. This is a breakthrough
achievement when compared both to the previous EMCD resolution (200 nm) or the
best XMCD experiments (approx. 20 nm), with an improvement of two and one order
of magnitude, respectively.


title:
Energy levels of a two-dimensional hydrogen atom with spin-orbit Rashba
  interaction

abstract:
  Electronic bound states around charged impurities in two-dimensional systems
with structural inversion asymmetry can be described in terms of a
two-dimensional hydrogen atom in the presence of a Rashba spin-orbit
interaction. Here, the energy levels of the bound electron are evaluated
numerically as a function of the spin-orbit interaction, and analytic
expressions for the weak and strong spin-orbit coupling limits are compared
with the numerical results. It is found that, besides the level splitting due
to the lack of inversion symmetry, the energy levels are lowered for
sufficiently strong spin-orbit coupling, indicating that the electron gets more
tightly bound to the ion as the spin-orbit interaction increases. Similarities
and differences with respect to the two-dimensional Fr\"ohlich polaron with
Rashba coupling are discussed.