title: Conditions for exact equivalence of Kaluza-Klein and Yang-Mills theories

abstract:
  Although it is well known that Kaluza-Klein and Yang-Mills theories define
equivalent structures on principal bundles, the general conditions for
equivalence of their Lagrangians have not been explicitly stated. In this paper
we address the conditions for equivalence. The formulation of these conditions
is based on previous work in which the Dirac and Einstein equations were
unified in a tetrad formulation of the Kaluza-Klein model. This Kaluza-Klein
model is derived from mapping a bispinor field to a set of SL(2,R) x U(1) gauge
potentials and a complex scalar field. (A straightforward derivation of this
map using Hestenes' tetrad for the spin connection in a Riemannian space-time
is included in this paper.) Investigation of this Kaluza-Klein model reveals
two general conditions for establishing an exact equivalence between
Kaluza-Klein and Yang-Mills theories. The first condition is that only
horizontal vector fields occur in the Kaluza-Klein Lagrangian. The second is
that the scalar curvature be restricted to a sum over horizontal sectional
curvatures. We conclude that all known fields (including fermion fields) can
then be represented as components of a Kaluza-Klein metric together with scalar
fields.


title:
BPS Z(N) String Tensions, Sine Law and Casimir Scaling and Integrable
  Field Theories

abstract:
  We consider a Yang-Mills-Higgs theory with spontaneous symmetry breaking of
the gauge group G -> U(1)^r -> C(G), with C(G) being the center of G. We study
two vacua solutions of the theory which produce this symmetry breaking. We show
that for one of these vacua, the theory in the Coulomb phase has the mass
spectrum of particles and monopoles which is exactly the same as the mass
spectrum of particles and solitons of two dimensional affine Toda field theory.
That result holds also for N=4 Super Yang-Mills theories. On the other hand, in
the Higgs phase, we show that for each of the two vacua the ratio of the
tensions of the BPS Z(N) strings satisfy either the Casimir scaling or the sine
law scaling for G=SU(N). These results are extended to other gauge groups: for
the Casimir scaling, the ratios of the tensions are equal to the ratios of the
quadratic Casimir constant of specific representations; for the sine law
scaling, the tensions are proportional to the components of the left
Perron-Frobenius eigenvector of Cartan matrix and the ratios of tensions are
equal to the ratios of the soliton masses of affine Toda field theories.


title:
The Bipolar Engines of post-AGB stars: Transient Dynamos and Common
  Envelopes

abstract:
  The physical mechanism(s) responsible for transitioning from a spherical
Asymptotic Giant Branch (AGB) star to an asymmetric post-AGB (pAGB) object is
poorly understood. In particular, excess momenta in the outflows of pAGB
objects suggest that a binary may be required to supply an additional source of
energy and angular momentum. The extraction of rotational energy from the
engine is likely fundamental and may be facilitated if a dynamo is operating in
the interior. In this regard, single star magnetic outflow models have been
proposed as mechanisms for producing and shaping PNe, however these models
neglect the back-reaction of the large-scale magnetic field on the flow.
  Here we present a transient $\alpha-\Omega$ dynamo operating in the envelope
of an AGB star in (1) an isolated setting and (2) a common envelope in which
the secondary is a low-mass companion in-spiraling in the AGB interior. The
back reaction of the fields on the shear is included and differential rotation
and rotation deplete via turbulent dissipation and Poynting flux. For an
isolated star, the shear must be resupplied in order to sufficiently sustain
the dynamo. We comment on the energy requirements that convection must satisfy
to accomplish this. For the common envelope case, a robust dynamo can result as
the companion provides an additional source of energy and angular momentum.


title: Evidence for a Preferred Handedness of Spiral Galaxies

abstract:
  In this article I study the distribution of spiral galaxies in the Sloan
Digital Sky Survey (SDSS) to investigate whether the universe has an overall
handedness. A preference for spiral galaxies in one sector of the sky to be
left-handed or right-handed spirals would indicate a preferred handedness. The
SDSS data show a strong signal for such an asymmetry with a probability <0.2%.
The asymmetry axis is at (RA,dec) ~(202 deg,25 deg) with an uncertainty ~15
deg. The axis appears to be correlated with that of the quadrupole and octopole
moments in the WMAP microwave sky survey, an unlikely alignment that has been
dubbed "the axis of evil". Our Galaxy is aligned with its spin axis along the
same direction as the majority of the spirals.


title: Binary Models for Marginal Independence

abstract:
  Log-linear models are a classical tool for the analysis of contingency
tables. In particular, the subclass of graphical log-linear models provides a
general framework for modelling conditional independences. However, with the
exception of special structures, marginal independence hypotheses cannot be
accommodated by these traditional models. Focusing on binary variables, we
present a model class that provides a framework for modelling marginal
independences in contingency tables. The approach taken is graphical and draws
on analogies to multivariate Gaussian models for marginal independence. For the
graphical model representation we use bi-directed graphs, which are in the
tradition of path diagrams. We show how the models can be parameterized in a
simple fashion, and how maximum likelihood estimation can be performed using a
version of the Iterated Conditional Fitting algorithm. Finally we consider
combining these models with symmetry restrictions.


title: The halo by halo missing baryon problem

abstract:
  The global missing baryon problem - that the sum of observed baryons falls
short of the number expected form BBN - is well known. In addition to this,
there is also a local missing baryon problem that applies to individual dark
matter halos. This halo by halo missing baryon problem is such that the
observed mass fraction of baryons in individual galaxies falls short of the
cosmic baryon fraction. This deficit is a strong function of circular velocity.
I give an empirical estimate of this function, and note the presence of a
critical scale of ~900 km/s therein. I also briefly review Omega_b from BBN,
highlighting the persistent tension between lithium and the CMB, and discuss
some pros and cons of individual galaxies and clusters of galaxies as potential
reservoirs of dark baryons.


title:
Methods of Modern Differential Geometry in Quantum Chemistry: TD
  Theories on Grassmann and Hartree-Fock Manifolds

abstract:
  Hamiltonian and Schrodinger evolution equations on finite-dimensional
projective space are analyzed in detail. Hartree-Fock (HF) manifold is
introduced as a submanifold of many electron projective space of states.
Evolution equations, exact and linearized, on this manifold are studied.
Comparison of matrices of linearized Schrodinger equations on many electron
projective space and on the corresponding HF manifold reveals the appearance in
the HF case a constraining matrix that involves matrix elements of
many-electron Hamiltonian between HF state and double excited determinants.
Character of dependence of transition energies on the matrix elements of
constraining matrix is established by means of perturbation analysis. It is
demonstrated that success of time-dependent HF theory in calculation of
transition energies is mainly due to the wrong behavior of these energies as
functions of matrix elements of constraining matrix as compared with the exact
transition energies


title: Origin and propagation of cosmic rays (some highlights)

abstract:
  The detection of high-energy particles, cosmic rays (CRs), deep inside the
heliosphere implies that there are, at least, three distinctly different stages
in the lifetime of a CR particle: acceleration, propagation in the interstellar
medium (ISM), and propagation in the heliosphere. Gamma rays produced by
interactions of CRs with gas, radiation, and magnetic fields can be used to
study their spectra in different locations. Still, accurate direct measurements
of CR species inside the heliosphere (such as their spectra and abundances) are
extremely important for the understanding of their origin and propagation. In
this paper, an emphasis is made on very recent advances and especially on those
where GLAST and PAMELA observations can lead to further progress in our
understanding of CRs.


title: Pressure-induced metal-insulator transition in MgV_2O_4

abstract:
  On the basis of experimental thermoelectric power results and ab initio
calculations, we propose that a metal-insulator transition takes place at high
pressure (approximately 6 GPa) in MgV_2O_4.


title: Equivariant Satake category and Kostant-Whittaker reduction

abstract:
  We explain (following V. Drinfeld) how the equivariant derived category of
the affine Grassmannian can be described in terms of coherent sheaves on the
Langlands dual Lie algebra equivariant with respect to the adjoint action, due
to some old results of V. Ginzburg. The global cohomology functor corresponds
under this identification to restricti on to the Kostant slice. We extend this
description to loop rotation equivariant derived category, linking it to
Harish-Chandra bimodules for the Langlands dual Lie algebra, so that the global
cohomology functor corresponds to the quantum Kostant-Whittaker reduction of a
Harish-Chandra bimodule. We derive a conjecture from math.AG/0306413 which
identifies the loop-rotation equivariant homology of the affine Grassmannian
with quantized completed Toda lattice.


title: Higgs production at the LHC in warped extra-dimensional models

abstract:
  The extra-dimensional model in which the bulk geometry is a slice of anti-de
Sitter space is a particularly attractive extension of the Standard Model as it
allows to address the gauge hierarchy problem, as well as the mass hierarchy
prevailing among fermions. However, to allow for the masses of the Kaluza-Klein
excitations of the known particles to be near the Terascale without conflicting
with the high-precision electroweak data, one needs to promote the gauge
symmetry to a left-right structure SU(2)_L x SU(2)_R x U(1) which incorporates
a new quark b', the SU(2)_R doublet partner of the heavy top quark. We show
that this new quark will contribute to the main production process of Higgs
bosons at the LHC: the gluon-gluon fusion mechanism which proceeds through
heavy quark triangular loops. In most of the parameter space in which the
measured values of the heavy t,b quark masses are reproduced, the gg -> Higgs
production cross section is significantly altered, even if the b' quark is too
heavy to be directly accessible, m_b' > ~1TeV. Finally, we briefly discuss the
new Higgs production and decay channels involving the b' quark.


title: $N_{\p}$-type quotient modules on the torus

abstract:
  Structure of the quotient modules in $\hh$ is very complicated. A good
understanding of some special examples will shed light on the general picture.
This paper studies the so-call $N_{\p}$-type quotient modules, namely, quotient
modules of the form $\hh\ominus [z-\p]$, where $\p (w)$ is a function in the
classical Hardy space $H^2(\G)$ and $[z-\p]$ is the submodule generated by
$z-\p (w)$. This type of quotient modules serve as good examples in many
studies. A notable feature of the $N_{\p}$-type quotient module is its close
connections with some classical single variable operator theories.


title: Inconsistency of the non-standard definition of work

abstract:
  We show that the recently postulated non-standard definition of work
proportional to force variation rather than to displacement [A. Imparato and L.
Peliti, cond-mat arXiv:0706.1134v1] is thermodynamically inconsistent at both
microscopic and macroscopic scales and leads to non-physical results, including
free energy changes that depend on arbitrary parameters.


title:
Energy Measurements and Preparation of Canonical Phase States of a
  Nano-Mechanical Resonator

abstract:
  We show that a continuous quantum non-demolition measurement of the energy of
a nanomechanical resonator can be achieved by monitoring the resonator with a
quantum point contact via a Cooper-pair box. This technique can further be used
to prepare highly non-classical states of two resonators, such as canonical
phase-reference states, and so-called "noon" states.


title: Approximate reduction of dynamical systems

abstract:
  The reduction of dynamical systems has a rich history, with many important
applications related to stability, control and verification. Reduction of
nonlinear systems is typically performed in an exact manner - as is the case
with mechanical systems with symmetry--which, unfortunately, limits the type of
systems to which it can be applied. The goal of this paper is to consider a
more general form of reduction, termed approximate reduction, in order to
extend the class of systems that can be reduced. Using notions related to
incremental stability, we give conditions on when a dynamical system can be
projected to a lower dimensional space while providing hard bounds on the
induced errors, i.e., when it is behaviorally similar to a dynamical system on
a lower dimensional space. These concepts are illustrated on a series of
examples.


title: Subsonic Mechanical Alignment of Irregular Grains

abstract:
  We show that grains can be efficiently aligned by interacting with a subsonic
gaseous flow. The alignment arises from grains having irregularities that
scatter atoms with different efficiency in the right and left directions. The
grains tend to align with long axes perpendicular to magnetic field, which
corresponds to Davis-Greenstein predictions. Choosing conservative estimates,
scattering efficiency of impinging atoms and conservative ``degree of
helicity'', the alignment of helical grains is much more efficient than the
Gold-type alignment processes.


title: Search for Frame-Dragging-Like Signals Close to Spinning Superconductors

abstract:
  High-resolution accelerometer and laser gyroscope measurements were performed
in the vicinity of spinning rings at cryogenic temperatures. After passing a
critical temperature, which does not coincide with the material's
superconducting temperature, the angular acceleration and angular velocity
applied to the rotating ring could be seen on the sensors although they are
mechanically de-coupled. A parity violation was observed for the laser
gyroscope measurements such that the effect was greatly pronounced in the
clockwise-direction only. The experiments seem to compare well with recent
independent tests obtained by the Canterbury Ring Laser Group and the
Gravity-Probe B satellite. All systematic effects analyzed so far are at least
3 orders of magnitude below the observed phenomenon. The available experimental
data indicates that the fields scale similar to classical frame-dragging
fields. A number of theories that predicted large frame-dragging fields around
spinning superconductors can be ruled out by up to 4 orders of magnitude.


title: How to be correct, lazy and efficient ?

abstract:
  This paper is an introduction to Lambdix, a lazy Lisp interpreter implemented
at the Research Laboratory of Paris XI University (Laboratoire de Recherche en
Informatique, Orsay). Lambdix was devised in the course of an investigation
into the relationship between the semantics of programming languages and their
implementation; it was used to demonstrate that in the Lisp domain, semantic
correctness is consistent with efficiency, contrary to what has often been
claimed. The first part of the paper is an overview of well-known semantic
difficulties encountered by Lisp as well as an informal presentation of
Lambdix; it is shown that the difficulties which Lisp encouters do not arise in
Lambdix. The second part is about efficiency in implementation models. It
explains why Lambdix is better suited for lazy evaluation than previous models.
The section ends by giving comparative execution time tables.


title: Coherently driven non-classical light emission from a quantum dot

abstract:
  Narrow line-widths and the possibility of enhanced spontaneous emission via
coupling to microcavities make semiconductor quantum dots ideal for harnessing
coherent quantum phenomena at the single photon level. So far, however, all
approaches have relied on incoherent pumping, which limits the desirable
properties of the emission. In contrast, coherent excitation was recognized to
be necessary for providing both improved photon indistinguishability and high
efficiency, and offers the quantum control capabilities required for basic
qubit manipulations. Here we achieve, for the first time, resonant and coherent
excitation of a quantum dot with simultaneous collection of the non-classical
photon emission. Second-order correlation measurements show the unique
signature of a coherently-driven two-level quantum emitter: the photon
statistics become oscillatory at high driving fields, reflecting the coherent
evolution of the excitonic ground state of the quantum dot.


title:
Characterization of the hot Neptune GJ 436b with Spitzer and
  ground-based observations

abstract:
  We present Spitzer Space Telescope infrared photometry of a secondary eclipse
of the hot Neptune GJ436b. The observations were obtained using the 8-micron
band of the InfraRed Array Camera (IRAC). The data spanning the predicted time
of secondary eclipse show a clear flux decrement with the expected shape and
duration. The observed eclipse depth of 0.58 mmag allows us to estimate a
blackbody brightness temperature of T_p = 717 +- 35 K at 8 microns. We compare
this infrared flux measurement to a model of the planetary thermal emission,
and show that this model reproduces properly the observed flux decrement. The
timing of the secondary eclipse confirms the non-zero orbital eccentricity of
the planet, while also increasing its precision (e = 0.14 +- 0.01). Additional
new spectroscopic and photometric observations allow us to estimate the
rotational period of the star and to assess the potential presence of another
planet.


title:
Levi-Civita regularization and geodesic flows for the `curved' Kepler
  problem

abstract:
  We introduce the regularization Levi-Civita parameter for the `curved
Kepler', i.e., motion under the `Kepler-Coulomb' potential in a configuration
space with any constant curvature and metric of any signature type. Consistent
use of this parameter allows to solve the problem of motion (orbit shape and
time evolution along the orbit), thereby extending the use of the Levi-Civita
parameter beyond the usual Kepler problem in a flat Euclidean configuration
space. A `universal' description, where all relations are applicable to the
motions in any space and with any energy follow from our approach, with no need
to discuss separately the cases where the configuration space is flat or where
energy vanishes.
  We also discuss the connection of this `curved Kepler' problem with a
geodesic flow. The well known results by Moser, Osipov and Belbruno are shown
to hold essentially unchanged beyond the flat Euclidean configuration space.
`Curved' Kepler motions with a fixed value of the constant of motion
$\sigma:=-(2E - \kappa_1\kappa_2 J^2)$ on any curved configuration space with
constant curvature $\kappa_1$ and metric of signature type $\kappa_2$ can be
identified with the geodesic flow on a space with curvature $\sigma$ and metric
of the same signature type.


title:
Global regulation of genome duplication in eukaryotes: an overview from
  the epifluorescence microscope

abstract:
  In eukaryotes, DNA replication is initiated along each chromosome at multiple
sites called replication origins. Locally, each replication origin is
"licensed", or specified, at the end of the M and the beginning of G1 phases of
the cell cycle. During S phase when DNA synthesis takes place, origins are
activated in stages corresponding to early and late replicating domains. The
staged and progressive activation of replication origins reflects the need to
maintain a strict balance between the number of active replication forks and
the rate at which DNA synthesis procedes. This suggests that origin densities
(frequency of intiation) and replication fork movement (rates of elongation)
must be co-regulated in order to guarantee the efficient and complete
duplication of each subchromosomal domain. Emerging evidence supports this
proposal and suggests that the ATM/ATR intra-S phase checkpoint plays an
important role in the co-regulation of initiation frequencies and rates of
elongation. In the following, we review recent results concerning the
mechanisms governing the global regulation of DNA replication and discuss the
roles these mechanisms play in maintaining genome stability during both a
normal and perturbed S phase.


title: Foliations on quaternion CR-submanifolds

abstract:
  The purpose of this paper is to study the canonical foliations of a
quaternion CR-submanifold of a quaternion K\"{a}hler manifold.


title: Testing cold dark matter with the low mass Tully-Fisher relation

abstract:
  The galaxy circular velocity function at small masses is related to the
matter power spectrum on small scales. Although this function is well-studied
for Local Group dwarfs, theoretical predictions and observational measurements
are difficult for satellite galaxies, because of ram pressure and tidal
stripping. By contrast, isolated dwarf galaxies are less affected by these
processes, and almost always have enough 21cm emission to trace their dynamics
robustly. Here, we test cold dark matter cosmology using isolated low mass
dwarf galaxies from the SDSS with measured 21cm widths. We find consistency
between the predicted and observed number density of isolated galaxies down to
circular velocities of 50 km/s. Our technique yields a direct test of
small-scale cosmology independent of the Lyman-alpha forest power spectrum, but
our sample is currently statistically less powerful: warm dark matter particles
heavier than 0.5 keV cannot be ruled out. Our major systematic uncertainty is
the surface brightness limit of the SDSS. Blind HI surveys, such as the ALFALFA
survey on Arecibo, will uncover a larger number of isolated low mass galaxies
and increase the power of our constraints. With our sample, we also find that
the Tully-Fisher relation for dwarf galaxies is a strong function of
environment, and that the baryonic fraction is only a weak function of mass.
These results suggest that for dwarf galaxies, gas loss is dominated by
external, not internal, processes. [abridged]


title: Strangulation in Galaxy Groups

abstract:
  We use a cosmological chemodynamical simulation to study how the group
environment impacts the star formation properties of disk galaxies. The
simulated group has a total mass of M~8x10^12 Msun and a total X-ray luminosity
of L_X~10^41 erg s^-1. Our simulation suggests that ram pressure is not
sufficient in this group to remove the cold disk gas from a V_rot~150 km s^-1
galaxy. However, the majority of the hot gas in the galaxy is stripped over a
timescale of approximately 1 Gyr. Since the cooling of the hot gas component
provides a source for new cold gas, the stripping of the hot component
effectively cuts off the supply of cold gas. This in turn leads to a quenching
of star formation. The galaxy maintains the disk component after the cold gas
is consumed, which may lead to a galaxy similar to an S0. Our self-consistent
simulation suggests that this strangulation mechanism works even in low mass
groups, providing an explanation for the lower star formation rates in group
galaxies relative to galaxies in the field.


title: Bent-Double Radio Sources as Probes of the Intragroup Medium

abstract:
  Galaxy groups likely contain a significant fraction of the total baryonic
mass in the local universe within their intragroup medium (IGM). However, aside
from a handful of UV absorption line and X-ray observations, almost nothing is
known about the IGM. We present early results from a research program that
combines low-frequency radio continuum observations and optical spectroscopy of
bent-double radio sources and their neighbors in groups of galaxies. These
observations allow us to probe the density of the IGM to an unprecedented
degree by examining its impact on the jets of radio galaxies.


title: Charging of Fractal Dust Agglomerates in a Plasma Environment

abstract:
  The charge on micron-sized dust grains plays a crucial role in the structure
and evolution of forming aggregates within the dust population during the
coagulation process. The manner in which the charge is arranged on developing
irregular structures can affect the fractal dimension of aggregates formed
during collisions, which in turn influences the coagulation rate and size
evolution of the dust cloud. Preliminary models for the charge evolution on
fractal aggregates immersed in a plasma environment calculated using a
modification to the orbital-motion-limited (OML) theory are presented in this
paper. The model calculates currents to each point on the aggregate surface
using a line-of-sight (LOS) approximation: only those electron or ion
trajectories which are not blocked by another grain within the aggregate
contribute to the charging current. Both the total charge and the dipole moment
are calculated for the dust aggregate. While most coagulation theories assume
that it is difficult for like-charged grains to coagulate, the OML_LOS
approximation indicates that the electric potentials of aggregate structures
are often reduced enough to allow significant coagulation.


title:
Electro-Optic Search for Critical Divergence of the Charge-Density-Wave
  Diffusion Constant at the Onset of Depinning

abstract:
  We have used electro-reflectance measurements to study charge-density-wave
(CDW) polarization dynamics at voltages near the CDW depinning onset (Von) in
the quasi-one-dimensional conductor K0.3MoO3 ("blue bronze"). For low voltages,
where the phase-slip rate is low, it is expected that the polarization
relaxation time should be inversely proportional to the CDW diffusion constant,
which is expected to diverge at Von. At T=78 K, we observe saturation of the
relaxation time at low voltages, suggesting that we are in the low phase-slip
limit and allowing us to estimate the non-critical value of the CDW diffusion
constant D=0.02cm2/s, consistent with the measured phason velocity. At other
temperatures, the relaxation time increases with decreasing volage even at the
lowest voltages we could measure. In no case do we observe the expected
"critical speeding up", setting an upper limit on the critical region of (V/Von
-1)crit < 0.06.


title: Fundamental Superstrings as Holograms

abstract:
  The worldsheet of a macroscopic fundamental superstring in the Green-Schwarz
light-cone gauge is viewed as a possible boundary hologram of the near horizon
region of a small black string. For toroidally compactified strings, the
hologram has global symmetries of AdS_3 \times S^{d-1} \times T^{8-d}, (d
=3,..,8), only some of which extend to local conformal symmetries. We construct
the bulk string theory in detail for the particular case of d=3. The symmetries
of the hologram are correctly reproduced from this exact worldsheet description
in the bulk. Moreover, the central charge of the boundary Virasoro algebra
obtained from the bulk agrees with the Wald entropy of the associated small
black holes. This construction provides an exact CFT description of the near
horizon region of small black holes both in Type-II and heterotic string theory
arising from multiply wound fundamental superstrings.


title: Localized states at zigzag edges of bilayer graphene

abstract:
  We report the existence of zero energy surface states localized at zigzag
edges of bilayer graphene. Working within the tight-binding approximation we
derive the analytic solution for the wavefunctions of these peculiar surface
states. It is shown that zero energy edge states in bilayer graphene can be
divided into two families: (i) states living only on a single plane, equivalent
to surface states in monolayer graphene; (ii) states with finite amplitude over
the two layers, with an enhanced penetration into the bulk. The bulk and
surface (edge) electronic structure of bilayer graphene nanoribbons is also
studied, both in the absence and in the presence of a bias voltage between
planes.


title: Structure and Vertical Modes in Finite 2D Plasma Crystals

abstract:
  In this research, formation of finite two-dimensional (2D) plasma crystals
was numerically simulated. The structure was investigated for systems with
various Debye length and it was found there is a transition from a complete
hexagonal structure to a structure with concentric rings on the outer edge and
hexagonal lattice in the interior as the Debye length increases. The vertical
as well as horizontal oscillation modes thermally excited in the 2D dust
coulomb clusters were investigated. The horizontal mode spectra is shown to
agree with published results while the vertical mode spectra obtained from
numerical simulation and analytical method agree with one another. The
frequency of the vertical modes is shown to have a maximum corresponding to the
whole system acting as a solid plane. For low frequency modes, the largest
amplitude particle motion is concentrated in a few inner rings with the outer
rings remaining almost motionless in contrast to the horizontal modes for which
the strongest motion of the particles is concentrated in the inner rings at
high frequencies.


title: One-way quantum computing in optical lattices with many atom addressing

abstract:
  One of the fundamental conditions for one-way quantum computation (1WQC) is
the ability to make sequential measurements on isolated qubits that comprise
the highly entangled resource for 1WQC, the cluster state. This has been a
significant impediment in the implementation of 1WQC with ultracold atoms
confined in optical lattices, because the width of the measuring lasers is
generally much greater than the atomic (qubit) spacing. We demonstrate that
deterministic 1WQC is nevertheless possible, with a polynomial increase in the
number of operations, as long as the center of the beams can be positioned with
high accuracy. Extending the number of cluster atoms, the scheme is also able
to compensate for accidental measurements of an arbitrary number of nearby
qubits.


title:
Study of the spin-$\frac32$ Hubbard-Kondo lattice model by means of the
  Composite Operator Method

abstract:
  We study the spin-$\frac32$ Hubbard-Kondo lattice model by means of the
Composite Operator Method, after applying a Holstein-Primakov transformation.
The spin and particle dynamics in the ferromagnetic state are calculated by
taking into account strong on-site correlations between electrons and
antiferromagnetic exchange among $\frac32$ spins, together with usual Hund
coupling between electrons and spins.


title:
Room temperature spin filtering in epitaxial cobalt-ferrite tunnel
  barriers

abstract:
  We report direct experimental evidence of room temperature spin filtering in
magnetic tunnel junctions (MTJs) containing CoFe2O4 tunnel barriers via
tunneling magnetoresistance (TMR) measurements.
Pt(111)/CoFe2O4(111)/gamma-Al2O3(111)/Co(0001) fully epitaxial MTJs were grown
in order to obtain a high quality system, capable of functioning at room
temperature. Spin polarized transport measurements reveal significant TMR
values of -18% at 2 K and -3% at 290 K. In addition, the TMR ratio follows a
unique bias voltage dependence that has been theoretically predicted to be the
signature of spin filtering in MTJs containing magnetic barriers. CoFe2O4
tunnel barriers therefore provide a model system to investigate spin filtering
in a wide range of temperatures.


title:
Competing Ordered Phases in URu2Si2: Hydrostatic Pressure and
  Re-substitution

abstract:
  A persistent kink in the pressure dependence of the \hidden order" (HO)
transition temperature of URu2-xRexSi2 is observed at a critical pressure Pc=15
kbar for 0 < x < 0.08. In URu2Si2, the kink at Pc is accompanied by the
destruction of superconductivity; a change in the magnitude of a spin
excitation gap, determined from electrical resistivity measurements; and a
complete gapping of a portion of the Fermi surface (FS), inferred from a change
in scattering and the competition between the HO state and superconductivity
for FS fraction.


title:
Emergence of noncollinear magnetic ordering in small magnetic clusters:
  Mn$_n$ and As@Mn$_n$

abstract:
  Using first-principles density functional calculations, we have studied the
magnetic ordering in pure Mn$_n$ ($n=2-$10, 13, 15, 19) and As@Mn$_n$
($n=1-$10) clusters. Although, for both pure and doped manganese clusters,
there exists many collinear and noncollinear isomers close in energy, the
smaller clusters with $n\leqslant$5 have collinear magnetic ground state and
the emergence of noncollinear ground states is seen for $n\geqslant$6 clusters.
Due to strong $p-d$ hybridization in As@Mn$_n$ clusters, the binding energy is
substantially enhanced and the magnetic moment is reduced compared to the
corresponding pure Mn$_n$ clusters.


title: More hilltop inflation models

abstract:
  Using analytic expressions, we explore the parameter space for hilltop
inflation models with a potential of the form $V_0\pm m^2\phi^2 -a\phi^p$. With
the positive sign and p>2 this converts the original hybrid inflation model
into a hilltop model, allowing the spectral index to agree with the observed
value n=0.95. In some cases the observed value is theoretically favored, while
in others there is only the generic prediction $|n-1|\lsim 1$.


title:
Engineering Silicon Nanocrystals: Theoretical study of the effect of
  Codoping with Boron and Phosphorus

abstract:
  We show that the optical and electronic properties of nanocrystalline silicon
can be efficiently tuned using impurity doping. In particular, we give
evidence, by means of ab-initio calculations, that by properly controlling the
doping with either one or two atomic species, a significant modification of
both the absorption and the emission of light can be achieved. We have
considered impurities, either boron or phosphorous (doping) or both (codoping),
located at different substitutional sites of silicon nanocrystals with size
ranging from 1.1 nm to 1.8 nm in diameter. We have found that the codoped
nanocrystals have the lowest impurity formation energies when the two
impurities occupy nearest neighbor sites near the surface. In addition, such
systems present band-edge states localized on the impurities giving rise to a
red-shift of the absorption thresholds with respect to that of undoped
nanocrystals. Our detailed theoretical analysis shows that the creation of an
electron-hole pair due to light absorption determines a geometry distortion
that in turn results in a Stokes shift between adsorption and emission spectra.
In order to give a deeper insight in this effect, in one case we have
calculated the absorption and emission spectra going beyond the single-particle
approach showing the important role played by many-body effects. The entire set
of results we have collected in this work give a strong indication that with
the doping it is possible to tune the optical properties of silicon
nanocrystals.


title: Structure, bonding and magnetism in cobalt clusters

abstract:
  The structural, electronic and magnetic properties of Co$_n$ clusters
($n=2-$20) have been investigated using density functional theory within the
pseudopotential plane wave method. An unusual hexagonal growth pattern has been
observed in the intermediate size range, $n=15-$20. The cobalt atoms are
ferromagnetically ordered and the calculated magnetic moments are found to be
higher than that of corresponding hcp bulk value, which are in good agreement
with the recent Stern-Gerlach experiments. The average coordination number is
found to dominate over the average bond length to determine the effective
hybridization and consequently the cluster magnetic moment.


title:
Occupation Statistics of Critical Branching Random Walks in Two or
  Higher Dimensions

abstract:
  Consider a critical nearest neighbor branching random walk on the
$d$-dimensional integer lattice initiated by a single particle at the origin.
Let $G_{n}$ be the event that the branching random walk survives to generation
$n$. We obtain limit theorems conditional on the event $G_{n}$ for a variety of
occupation statistics: (1) Let $V_{n}$ be the maximal number of particles at a
single site at time $n$. If the offspring distribution has finite $\alpha$th
moment for some integer $\alpha\geq 2$, then in dimensions 3 and higher,
$V_n=O_p(n^{1/\alpha})$; and if the offspring distribution has an exponentially
decaying tail, then $V_n=O_p(\log n)$ in dimensions 3 and higher, and
$V_n=O_p((\log n)^2)$ in dimension 2. Furthermore, if the offspring
distribution is non-degenerate then $P(V_n\geq \delta \log n | G_{n})\to 1$ for
some $\delta >0$. (2) Let $M_{n} (j)$ be the number of multiplicity-$j$ sites
in the $n$th generation, that is, sites occupied by exactly $j$ particles. In
dimensions 3 and higher, the random variables $M_{n} (j)/n$ converge jointly to
multiples of an exponential random variable. (3) In dimension 2, the number of
particles at a "typical" site (that is, at the location of a randomly chosen
particle of the $n$th generation) is of order $O_p(\log n)$, and the number of
occupied sites is $O_p(n/\log n)$.


title: On Cosmological Implications of Gravitational Trace Anomaly

abstract:
  We study the infrared effective theory of gravity that stems from the quantum
trace anomaly. Quantum fluctuations of the metric induce running of the
cosmological constant and the Newton constant at cosmological scales. By
imposing the generalized Bianchi identity we obtain a prediction for the scale
dependence of the dark matter and dark energy densities in terms of the
parameters of the underlying conformal theory. For certain values of the model
parameters the dark energy equation of state and the observed spectral index of
the primordial density fluctuations can be simultaneously reproduced.


title:
Cobaltocene Encapsulation Into Single-walled Carbon Nanotubes: A
  Molecular Dynamics Investigation

abstract:
  Recently (PRL 96, 106804 (2006)) it was suggested that cobaltocene(CC)
molecules encapsulated into (7,7) carbon nanotubes (CNT@(7,7)) could be the
basis for new spintronic devices. We show here based on impact molecular
dynamics and DFT calculations that when dynamical aspects are explicitly
considered the CC encapsulation into CNT@(7,7) does not occur, it is prevented
by a dynamic barrier mainly due to van der Waals interactions. Our results show
that CNT@(13,0) having enough axial space for encapsulation but no enough one
to allow freely rotation of the cobaltocene molecule would be a feasible
candidate to such application.


title: Reheating Closed String Inflation

abstract:
  Protecting the inflationary potential from quantum corrections typically
requires symmetries that constrain the form of couplings of the inflaton to
other sectors. We will explore how these restrictions affect reheating in
models with UV completions. In particular, we look at how reheating occurs when
inflation is governed by closed strings, using N-flation as an example. We find
that coupling the inflaton preferentially to the Standard Model is difficult,
and hidden sectors are typically reheated. Observational constraints are only
met by a fraction of the models. In some working models, relativistic relics in
the hidden sector provide dark matter candidates with masses that range from
keV to PeV, with lighter masses being preferred.


title:
Near-Infrared Interferometric, Spectroscopic, and Photometric Monitoring
  of T Tauri Inner Disks

abstract:
  We present high angular resolution observations with the Keck Interferometer,
high dispersion spectroscopic observations with Keck/NIRSPEC, and near-IR
photometric observations from PAIRITEL of a sample of 11 solar-type T Tauri
stars in 9 systems. We use these observations to probe the circumstellar
material within 1 AU of these young stars, measuring the
circumstellar-to-stellar flux ratios and angular size scales of the 2.2 micron
emission. Our sample spans a range of stellar luminosities and mass accretion
rates, allowing investigation of potential correlations between inner disk
properties and stellar or accretion properties. We suggest that the mechanism
by which the dusty inner disk is truncated may depend on the accretion rate of
the source; in objects with low accretion rates, the stellar magnetospheres may
truncate the disks, while sublimation may truncate dusty disks around sources
with higher accretion rates. We have also included in our sample objects that
are known to be highly variable (based on previous photometric and
spectroscopic observations), and for several sources, we obtained multiple
epochs of spectroscopic and interferometric data, supplemented by near-IR
photometric monitoring, to search for inner disk variability. While
time-variable veilings and accretion rates are observed in some sources, no
strong evidence for inner disk pulsation is found.


title:
Spin squeezing in optical lattice clocks via lattice-based QND
  measurements

abstract:
  Quantum projection noise will soon limit the best achievable precision of
optical atomic clocks based on lattice-confined neutral atoms. Squeezing the
collective atomic pseudo-spin via measurement of the clock state populations
during Ramsey interrogation suppresses the projection noise. We show here that
the lattice laser field can be used to perform ideal quantum non-demolition
measurements without clock shifts or decoherence and explore the feasibility of
such an approach in theory with the lattice field confined in a ring-resonator.
Detection of the motional sideband due to the atomic vibration in the lattice
wells can yield signal sizes a hundredfold above the projection noise limit.


title: Symmetry groups of non-simply-connected four-manifolds

abstract:
  Let $M$ be a closed, connected, orientable topological four-manifold with
$H_1(M)$ nontrivial and free abelian, $b_2(M)\ne 0, 2$, and $\chi(M)\ne 0$. We
show that if $G$ is a finite group of 2-rank $\le 1$ which admits a
homologically trivial, locally linear, effective action on $M$, then $G$ must
be cyclic.
  With additional assumptions to ensure orientability of some components of the
singular set (e.g. if $G$ acts by symplectic symmetries, or preserving a spin
structure), we also rule out $C_2 \times C_2$ actions.
  The proofs use equivariant cohomology, localization, and a careful study of
the first cohomology groups of the (potential) singular set.


title: The charge and spin sectors of the $t$-$t'$ Hubbard model

abstract:
  The charge and spin sectors, which are intimately coupled to the fermionic
one, of the $t$-$t'$ Hubbard model have been computed self-consistently within
the two-pole approximation. The relevant unknown correlators appearing in the
causal bosonic propagators have been computed by enforcing the constraints
dictated by the hydrodynamics and the algebra of the composite operators coming
into play. The proposed scheme of approximation extends previous calculations
made for the fermionic sector of the $t$-$t'$ Hubbard model and the bosonic
sector of the Hubbard model, which showed to be very effective to describe the
overdoped region of cuprates (the former) and the magnetic response of their
parent compounds (the latter).


title: Effective resistance on random electrical networks

abstract:
  This paper has been withdrawn. See v1 still available to understand the
problem: Proposition 2.2 is false. The error in the proof is in claim (3).
Then, the whole paper collapses. We do not have any correction for now. We
apologize to everyone.


title: Ergodicity in Strongly Correlated Systems

abstract:
  We present a concise, but systematic, review of the ergodicity issue in
strongly correlated systems. After giving a brief historical overview, we
analyze the issue within the Green's function formalism by means of the
equations of motion approach. By means of this analysis, we are able to
individuate the primary source of non-ergodic dynamics for a generic operator
and also to give a recipe to compute unknown quantities characterizing such a
behavior within the Composite Operator Method. Finally, we present examples of
non-trivial strongly correlated systems where it is possible to find a
non-ergodic behavior.


title: A class of solvable models in Condensed Matter Physics

abstract:
  In this paper, we show that there is a large class of fermionic systems for
which it is possible to find, for any dimension, a finite closed set of
eigenoperators and eigenvalues of the Hamiltonian. Then, the hierarchy of the
equations of motion closes and analytical expressions for the Green's functions
are obtained in terms of a finite number of parameters, to be self-consistently
determined. Several examples are given. In particular, for these examples it is
shown that in the one-dimensional case it is possible to derive by means of
algebraic constraints a set of equations which allow us to determine the
self-consistent parameters and to obtain a complete exact solution.


title: Green's Function Formalism for Highly Correlated Systems

abstract:
  We present the Composite Operator Method (COM) as a modern approach to the
study of strongly correlated electronic systems, based on the equation of
motion and Green's function method. COM uses propagators of composite operators
as building blocks at the basis of approximate calculations and algebra
constrains to fix the representation of Green's functions in order to maintain
the algebraic and symmetry properties.


title:
Poynting's theorem for planes waves at an interface: a scattering matrix
  approach

abstract:
  We apply the Poynting theorem to the scattering of monochromatic
electromagnetic planes waves with normal incidence to the interface of two
different media. We write this energy conservation theorem to introduce a
natural definition of the scattering matrix S. For the dielectric-dielectric
interface the balance equation lead us to the energy flux conservation which
express one of the properties of S: it is a unitary matrix. For the
dielectric-conductor interface the scattering matrix is no longer unitary due
to the presence of losses at the conductor. However, the dissipative term
appearing in the Poynting theorem can be interpreted as a single absorbing mode
at the conductor such that a whole S, satisfying flux conservation and
containing this absorbing mode, can be defined. This is a simplest version of a
model introduced in the current literature to describe losses in more complex
systems.


title: Quenched Dislocation Enhanced Supersolid Ordering

abstract:
  I show using Landau theory that quenched dislocations can facilitate the
supersolid (SS) to normal solid (NS) transition, making it possible for the
transition to occur even if it does not in a dislocation-free crystal. I make
detailed predictions for the dependence of the SS to NS transition temperature
T_c(L), superfluid density %\rho_S(T, L), and specific heat C(T,L) on
temperature T and dislocation spacing L, all of which can be tested against
experiments. The results should also be applicable to an enormous variety of
other systems, including, e.g., ferromagnets.


title:
Modulator noise suppression in the LISA Time-Delay Interferometric
  combinations

abstract:
  We previously showed how the measurements of some eighteen time series of
relative frequency or phase shifts could be combined (1) to cancel the phase
noise of the lasers, (2) to cancel the Doppler fluctuations due to non-inertial
motions of the six optical benches, and (3) to remove the phase noise of the
onboard reference oscillators required to track the photodetector fringes, all
the while preserving signals from passinggravitational waves. Here we analyze
the effect of the additional noise due to the optical modulators used for
removing the phase fluctuations of the onboard reference oscillators. We use a
recently measured noise spectrum of an individual modulator to quantify the
contribution of modulator noise to the first and second-generation Time-Delay
Interferometric (TDI) combinations as a function of the modulation frequency.
We show that modulator noise can be made smaller than the expected proof-mass
acceleration and optical-path noises if the modulation frequencies are larger
than $\approx 682$ MHz in the case of the unequal-arm Michelson TDI combination
$X_1$, $\approx 1.08$ GHz for the Sagnac TDI combination $\alpha_1$, and
$\approx 706$ MHz for the symmetrical Sagnac TDI combination $\zeta_1$. These
modulation frequencies are substantially smaller than previously estimated and
may lead to less stringent requirements on the LISA's oscillator noise
calibration subsystem.


title: Nucleon Structure and Hyperon Form factor from Lattice QCD

abstract:
  In this work, I report the latest lattice QCD calculations of nucleon and
hyperon structure from chiral fermions in 2+1-flavor dynamical simulations. All
calculations are done with a chirally symmetric fermion action, domain-wall
fermions, for valence quarks. % I begin with the latest lattice results on the
nucleon structure, focusing on results from RBC/UKQCD using 2+1-flavor chiral
fermion actions. We find the chiral-extrapolated axial coupling constant at
physical pion mass point to be 1.23(5), consistent with experimental value. The
renormalization constants for the structure functions are obtained from
RI/MOM-scheme non-perturbative renormalization. We find first moments of the
polarized and unpolarized nucleon structure functions at zero transfer momentum
to be 0.133(13) and 0.203(23) respectively, using continuum chiral
extrapolation. These are consistent with the experimental values, unlike
previous calculations which have been 50% larger. We also have a prediction for
the transversity, which we find to be 0.56(4). The twist-3 matrix element is
consistent with zero which agrees with the prediction of the Wandzura-Wilczek
relation.
  In the second half of this work, I report an indirect dynamical estimation of
the strangeness proton magnetic moments using mixed actions. With the analysis
of hyperon form factors and using charge symmetry, the strangeness of proton is
found to be $-0.066(26)$, consistent with the Adelaide-JLab Collaboration's
result. The hyperon $\Sigma$ and $\Xi$ axial coupling constants are also
performed for the first time in a lattice calculation, $g_{\Sigma\Sigma}=
0.441(14)$ and $g_{\Xi\Xi} = -0.277(11)$.


title: Modules of constant Jordan type

abstract:
  We introduce the class of modules of constant Jordan type for a finite group
scheme $G$ over a field $k$ of characteristic $p > 0$. This class is closed
under taking direct sums, tensor products, duals, Heller shifts and direct
summands, and includes endotrivial modules. It contains all modules in an
Auslander-Reiten component which has at least one module in the class. Highly
non-trivial examples are constructed using cohomological techniques. We offer
conjectures suggesting that there are strong conditions on a partition to be
the Jordan type associated to a module of constant Jordan type.


title: Quantum statistical measurements of an atom laser beam

abstract:
  We describe a scheme, operating in a manner analogous to a reversed Raman
output coupler, for measuring the phase-sensitive quadrature statistics of an
atom laser beam. This scheme allows for the transferral of the atomic field
statistics to an optical field, for which the quantum statistics may then be
measured using the well-developed technology of optical homodyne measurement.


title: Aspects of Density Fluctuations in Compressible MHD Turbulence

abstract:
  We study scaling relations of compressible isothermal strongly magnetized
turbulence using numerical simulations with resolution 512$^3$. We find a good
correspondence of our results with the Fleck (1996) model of compressible
hydrodynamic turbulence. In particular, we find that the density-weighted
velocity, i.e. $\boldsymbol{u} \equiv \rho^{1/3} \boldsymbol{v}$, proposed in
Kritsuk et al. (2007) obeys the Kolmogorov scaling, i.e. ${\cal E}_{u}(k)\sim
k^{-5/3}$ for the high Mach number turbulence. Similarly, we find that the
exponents of the third order structure functions for $\boldsymbol{u}$ stay
equal to unity for all Mach numbers studied. The scaling of higher order
correlations obeys the She-L\'{e}v\^{e}que (1994) scalings corresponding to the
two-dimensional dissipative structures, and this result does not change with
the Mach number either. In contrast to velocity $\boldsymbol{v}$ which exhibits
different scaling parallel and perpendicular to the local magnetic field, the
scaling of $\boldsymbol{u}$ is similar in both directions. In addition, we find
that the peaks of density create a hierarchy in which both physical and column
densities decrease with the scale in accordance to the Fleck (1996)
predictions. This hierarchy can be related ubiquitous small ionized and neutral
structures (SINS) in the interstellar gas. We believe that studies of
statistics of the column density peaks can provide both consistency check for
the turbulence velocity studies and insight into supersonic turbulence, when
the velocity information is not available.


title:
Correlation Inequalities for Generalized Potts Model: General Griffiths'
  Inequalities

abstract:
  In this paper, correlation inequalities which have been considered on Ising
model are extended to q-Potts model. It is considered on generalized Potts
model with interaction of any number of spins. We replace the set of spin
values $F=\{1,2,..., q\}$ by the centered set $F=\{-(q-1)/2,-(q-3)/2,...
,(q-3)/2,(q-1)/2\}$. Let $N$ be the subset of one-dimensional lattice with $n$
vertices, $\g=(\s_1,\s_2,...,\s_n):N \to F^c$ be a configuration where
${(\s_i)}_\g$ is the number which appears as the ith spin (component) in $\g$
and $\s_i$ be a random variable whose value at $\g$ is ${(\s_i)}_\g$. Define
$\s^R=\prod_{i \in R}\s_i$ for any list $R$ where any $i \in R$ implies that $i
\in N$. We first prove that $<\s^R > \ge 0$ then we prove that for any two
lists $R$ and $S$, we have $<\s^R \s^S >- < \s^R > < \s^S > \ge 0$.


title:
The phase structure of a chirally invariant lattice Higgs-Yukawa model -
  numerical simulations

abstract:
  The phase diagram of a chirally invariant lattice Higgs-Yukawa model is
explored by means of numerical simulations. The results revealing a rich phase
structure are compared to analytical large Nf calculations which we performed
earlier. The analytical and numerical results are in excellent agreement at
large values of Nf. In the opposite case the large Nf computation still gives a
good qualitative description of the phase diagram. In particular we find
numerical evidence for the predicted ferrimagnetic phase at intermediate values
of the Yukawa coupling constant and for the symmetric phase at strong Yukawa
couplings. Emphasis is put on the finite size effects which can hide the
existence of the latter symmetric phase.


title:
Spin wave dispersion based on the quasiparticle self-consistent $GW$
  method: NiO, MnO and $\alpha$-MnAs

abstract:
  We present spin wave dispersions in MnO, NiO, and $\alpha$-MnAs based on the
quasiparticle self-consistent $GW$ method (\qsgw), which determines an optimum
quasiparticle picture. For MnO and NiO, \qsgw results are in rather good
agreement with experiments, in contrast to the LDA and LDA+U description. For
$\alpha$-MnAs, we find a collinear ferromagnetic ground state in \qsgw, while
this phase is unstable in the LDA.


title: The complex Busemann-Petty problem on sections of convex bodies

abstract:
  The complex Busemann-Petty problem asks whether origin symmetric convex
bodies in $\C^n$ with smaller central hyperplane sections necessarily have
smaller volume. We prove that the answer is affirmative if $n\le 3$ and
negative if $n\ge 4.$


title: Performance Evaluation of a Multi-Agent Risk-Sensitive Tracking System

abstract:
  In this paper, we consider a simple linear exponential quadratic Gaussian
(LEQG) tracking problem for a multi-agent system. We study the dynamical
behaviors of the group as we vary the risk-sensitivity parameter, comparing in
particular the risk averse case to the LQG case. Then we consider the evolution
of the performance per agent as the number of agents in the system increases.
We provide some analytical as well as simulation results. In general, more
agents are beneficial only if noisy agent dynamics and/or imperfect
measurements are considered. The critical value of the risk sensitivity
parameter above which the cost becomes infinite increases with the number of
agents. In other words, for a fixed positive value of this parameter, there is
a minimum number of agents above which the cost remains finite.


title: Semifinite spectral triples associated with graph C*-algebras

abstract:
  We review the recent construction of semifinite spectral triples for graph
C^*-algebras. These examples have inspired many other developments and we
review some of these such as the relation between the semifinite index and the
Kasparov product, examples of noncommutative manifolds, and an index theorem in
twisted cyclic theory using a KMS state.


title: eta photoproduction and N* resonances

abstract:
  We investigate the eta photoproduction using the effective Lagrangian
approach at the tree level. We focus on the new nucleon resonance N*(1675),
which was reported by the GRAAL, CB-ELSA and Tohoku LNS, testing its possible
spin and parity states theoretically (J^P=1/2^+-,3/2^+-). In addition, we
include six nucleon resonances, D_13(1520), S_11(1535), S_11(1650), D_15(1675),
P_11(1710), P_13(1720) as well as the possible background contributions. We
calculate various cross sections including beam asymmetries for the neutron and
proton targets. We find noticeable isospin asymmetry in transition amplitudes
for photon and neutron targets. This observation may indicate that the new
resonance can be identified as a non-strangeness member of the baryon
antidecuplet.


title:
Special Relativity and Theory of Gravity via Maximum Symmetry and
  Localization -- In Honor of the 80th Birthday of Professor Qikeng Lu

abstract:
  Like Euclid, Riemann and Lobachevsky geometries on an almost equal footing,
based on the principle of relativity of maximum symmetry proposed by Lu and the
postulate on invariant universal constants, dS/AdS SR can be set up on an
almost equal footing with Einstein's SR. For dS-case, there is a coin-like
relation: A law of inertia in Beltrami atlas with Beltrami time simultaneity
for the PoR on one side. The proper-time simultaneity and a RW-like dS-space
with entropy and an accelerated expanding S^3 fitting the cosmological
principle on another. If our universe is asymptotic to the RW-like dS-space, it
should be slightly closed with an entropy bound. Contrarily, via its asymptotic
behavior, it can fix on Beltrami frames without `an argument in a circle' and
acts as the origin of inertia. There is a triality of conformal extensions of
three kinds of SR and their null physics on the projective boundary of a 5-d
AdS-space. Thus there is a dS-spacetime on the boundary of a vacuum of
supergravity. Gravity should be based on the localized PoR of full maximum
symmetry with a gauge-like dynamics. Thus, this may lead to theory of gravity
of corresponding local maximum symmetry. A simple model of dS-gravity
characterized by a dimensionless constant shows the features. Our universe may
already indicate that the dS SR and the dS-gravity be the foundation of large
scale physics.


title:
Stochastic evolution equations for nonlinear filtering of random fields
  in the presence of fractional Brownian sheet observation noise

abstract:
  The problem of nonlinear filtering of a random field observed in the presence
of a noise, modeled by a persistent fractional Brownian sheet of Hurst index
$(H_1,H_2)$ with $0.5<H_1,H_2<1$, is studied and a suitable version of the
Bayes' formula for the optimal filter is obtained. Two types of spatial
"fractional" analogues of the Duncan-Mortensen-Zakai equation are also derived:
one tracks evolution of the unnormalized optimal filter along an arbitrary
"monotone increasing" (in the sense of partial ordering in $\mathbb{R}^2$)
one-dimensional curve in the plane, while the other describes dynamics of the
filter along the paths that are truly two-dimensional. Although the paper deals
with the two-dimensional parameter space, the presented approach and results
extend to $d$-parameter random fields with arbitrary $d\geq 3$.


title: Exact solution of a model of qubit dephasing due to telegraph noise

abstract:
  We present a general and exact formalism for finding the evolution of a
quantum system subject to external telegraph noise. The various qubit
decoherence rates are determined by the eigenvalues of a transfer matrix. The
formalism can be applied to a qubit subject to an arbitrary combination of
dephasing and relaxational telegraph noise, in contrast to existing
non-perturbative methods that treat only one or the other of these limits. We
present 3 applications: 1) We obtain the full qubit dynamics on time scales
short compared with the enviromental correlation times. In the strong coupling
cases this reveals unexpected oscillations and induced magnetization
components; 2) We find in strong coupling case strong violations of the widely
used relation 1/T$_2$ = 1/2T$_1$ + 1/T$_{\phi}$, which is a result of
perturbation theory; 3) We discuss the effects of bang-bang and spin-echo
controls of the qubit dynamics in general settings of the telegraph noises.
%The result shows that these methods are not very effective in %reducing
decoherence arising from a single telegraph noise. Finally, we discuss the
extension of the method to the cases of many telegraph noise sources and
multiple qubits. The method still works when white noise is also present.


title: The quantum sinh-Gordon model in noncommutative (1+1) dimensions

abstract:
  Using twisted commutation relations we show that the quantum sinh-Gordon
model on noncommutative space is integrable, and compute the exact two-particle
scattering matrix. The model possesses a strong-weak duality, just like its
commutative counterpart.


title:
Light-Front Dynamics and AdS/QCD Correspondence: The Pion Form Factor in
  the Space- and Time-Like Regions

abstract:
  The AdS/CFT correspondence between string theory in AdS space and conformal
field theories in physical space-time leads to an analytic, semi-classical
model for strongly-coupled QCD which has scale invariance and dimensional
counting at short distances and color confinement at large distances. The
AdS/CFT correspondence also provides insights into the inherently
non-perturbative aspects of QCD such as the orbital and radial spectra of
hadrons and the form of hadronic wavefunctions. In particular, we show that
there is an exact correspondence between the fifth-dimensional coordinate of
anti-de Sitter (AdS) space $z$ and a specific light-front impact variable
$\zeta$ which measures the separation of the quark and gluonic constituents
within the hadron in ordinary space-time. This connection allows one to compute
the analytic form of the frame-independent light-front wavefunctions of mesons
and baryons, the fundamental entities which encode hadron properties and which
allow the computation of decay constants, form factors and other exclusive
scattering amplitudes. Relativistic light-front equations in ordinary
space-time are found which reproduce the results obtained using the
fifth-dimensional theory. As specific examples we compute the pion coupling
constant $f_\pi$, the pion charge radius $< r_\pi^2 >$ and examine the
propagation of the electromagnetic current in AdS space, which determines the
space and time-like behavior of the pion form factor and the pole of the $\rho$
meson.


title: Cha\^{i}nes de Markov Constructives Index\'{e}es par Z

abstract:
  Nous \'{e}tudions les cha\^{{\i}}nes de Markov $(X_n)_{n\in\mathbf{Z}}$
gouvern\'{e}es par une relation de r\'{e}currence de la forme
$X_{n+1}=f(X_n,V_{n+1})$, o\`{u} $(V_n)_{n\in\mathbf{Z}}$ est une suite de
variables al\'{e}atoires ind\'{e}pendantes et de m\^{e}me loi telle pour tout
$n\in \mathbf{Z}$, $V_{n+1}$ est ind\'{e}pendante de la suite
$((X_k,V_k))_{k\le n}$. L'objet de l'article est de donner une condition
n\'{e}cessaire et suffisante pour que les innovations $(V_n)_{n\in\mathbf{Z}}$
d\'{e}terminent compl\`{e}tement la suite $(X_n)_{n\in \mathbf{Z}}$ et de
d\'{e}crire l'information manquante dans le cas contraire.


title:
The C*-algebras qA\otimes K and S^2A\otimes K are asymptotically
  equivalent

abstract:
  Let $A$ be a separable $C^*$-algebra. We prove that its stabilized second
suspension $S^2A\otimes \mathcal K$ and the $C^*$-algebra $qA\otimes \mathcal
K$ constructed by Cuntz in the framework of his picture of KK-theory are
asymptotically equivalent. This means that there exist asymptotic morphisms
from each to the other whose compositions are homotopic to the identity maps.
This result yields an easy description of the natural transformation from
KK-theory to E-theory. One more corollary is the following. T. Loring ([3])
proved that any asymptotic morphism from $\qC$ to any $C^*$-algebra $B$ is
homotopic to a $\ast$-homomorphism. We prove that the same is true when $\C$ is
replaced by any nuclear $C^*$-algebra $A$ and when $B$ is stable.


title: Rational Landen transformations on the real line

abstract:
  The rational Landen transformation is a map on the space of coefficients of a
rational integrand that preserves the value of the integral. We provide a
family of these transformations that apply to rational integrands on the whole
line. Given an integer m, these transformations produce a numerical scheme to
evaluate the integral that is of order m.


title:
The Jancovici - Lebowitz - Manificat law for large fluctuations of
  random complex zeroes

abstract:
  By random complex zeroes we mean the zero set of a random entire function
whose Taylor coefficients are independent complex-valued Gaussian variables,
and the variance of the k-th coefficient is 1/k!. This zero set is distribution
invariant with respect to isometries of the complex plane. We study large
fluctuations of random complex zeroes and show that they obey the asymptotic
law that was discovered some time ago by Jancovici, Lebowitz and Manificat for
charge fluctuations of a Coulomb system of particles.


title:
The equation of state for the nuclear matter and the properties of the
  neutron star

abstract:
  The equation of state for the beta stable nuclear matter is calculated
numerically, and then the Tolman-Oppenheimer-Volkov equation for the structure
of the neutron star is solved in the fourth-order Runge-Kutta algorithm. It
shows the mass and radius of the neutron star are functions of the central
density of the neutron star and a maximum mass of 1.932 solar masses with a
corresponding radius of 9.340km is obtained. Considering the equation of state
of the nuclear matter must obey the causality, a new factor c is added in the
nuclear potential energy formula. Therefore, with a new equation of state for
the beta stable nuclear matter when c=0.15, a new maximum mass of 1.440 solar
masses with a radius of 9.765km for the neutron star is obtained. Finally, the
contribution of the cosmological constant to the structure of the neutron star
is discussed, and we find the cosmological constant has minimal or negligible
influence on the properties of the neutron star.


title: Distribution of Time-Averaged Observables for Weak Ergodicity Breaking

abstract:
  We find a general formula for the distribution of time-averaged observables
for systems modeled according to the sub-diffusive continuous time random walk.
For Gaussian random walks coupled to a thermal bath we recover ergodicity and
Boltzmann's statistics, while for the anomalous subdiffusive case a weakly
non-ergodic statistical mechanical framework is constructed, which is based on
L\'evy's generalized central limit theorem. As an example we calculate the
distribution of $\bar{X}$: the time average of the position of the particle,
for unbiased and uniformly biased particles, and show that $\bar{X}$ exhibits
large fluctuations compared with the ensemble average $<X>$.


title: Filtration shrinkage by level-crossings of a diffusion

abstract:
  We develop the mathematics of a filtration shrinkage model that has recently
been considered in the credit risk modeling literature. Given a finite
collection of points $x_1<...<x_N$ in $\mathbb{R}$, the region indicator
function $R(x)$ assumes the value $i$ if $x\in(x_{i-1},x_i]$. We take
$\mathbb{F}$ to be the filtration generated by $(R(X_t))_{t\geq0}$, where $X$
is a diffusion with infinitesimal generator $\mathcal{A}$. We prove a
martingale representation theorem for $\mathbb{F}$ in terms of stochastic
integrals with respect to $N$ random measures whose compensators have a simple
form given in terms of certain L\'{e}vy measures $F^{j\pm}_i$, which are
related to the differential equation $\mathcal{A}u=\lambda u$.


title: Low/Hard State Spectra of GRO J1655-40 Observed with Suzaku

abstract:
  The Galactic black-hole binary GRO J1655$-$40 was observed with Suzaku on
2005 September 22--23, for a net exposure of 35 ks with the X-ray Imaging
Spectrometer (XIS) and 20 ks with the Hard X-ray Detector (HXD). The source was
detected over a broad and continuous energy range of 0.7--300 keV, with an
intensity of $\sim$50 mCrab at 20 keV. At a distance of 3.2 kpc, the 0.7--300
keV luminosity is $ \sim 5.1 \times 10^{36}$ erg s$^{-1}$ ($\sim 0.7$ % of the
Eddington luminosity for a 6 $M_{\odot}$ black hole). The source was in a
typical low/hard state, exhibiting a power-law shaped continuum with a photon
index of $\sim 1.6$. During the observation, the source intensity gradually
decreased by 25% at energies above $\sim 3$ keV, and by 35% below 2 keV. This,
together with the soft X-ray spectra taken with the XIS, suggests the presence
of an independent soft component that can be represented by emission from a
cool ($\sim 0.2$ keV) disk. The hard X-ray spectra obtained with the HXD reveal
a high-energy spectral cutoff, with an e-folding energy of $\sim 200$ keV.
Since the spectral photon index above 10 keV is harder by $\sim 0.4$ than that
observed in the softer energy band, and the e-folding energy is higher than
those of typical reflection humps, the entire 0.7--300 keV spectrum cannot be
reproduced by a single thermal Comptonization model, even considering
reflection effects. Instead, the spectrum (except the soft excess) can be
successfully explained by invoking two thermal-Comptonization components with
different $y$-parameters. In contrast to the high/soft state spectra of this
object in which narrow iron absorption lines are detected with equivalent
widths of 60--100 eV, the present XIS spectra bear no such features beyond an
upper-limit equivalent width of 25 eV.


title: Finite quantum tomography via semidefinite programming

abstract:
  Using the the convex semidefinite programming method and superoperator
formalism we obtain the finite quantum tomography of some mixed quantum states
such as: qudit tomography, N-qubit tomography, phase tomography and coherent
spin state tomography, where that obtained results are in agreement with those
of References \cite{schack,Pegg,Barnett,Buzek,Weigert}.


title: A flat faint end of the Fornax cluster galaxy luminosity function

abstract:
  We analyse the photometric properties of the early-type Fornax cluster dwarf
galaxy population (M_V>-17 mag), based on a wide field imaging study of the
central cluster area in V and I band-passes with IMACS/Magellan at Las Campanas
Observatory. We create a fiducial sample of ~100 Fornax cluster dwarf
ellipticals (dEs) with -16.6<M_V<-8.8 mag in the following three steps: (1) To
verify cluster membership, we measured I-band surface brightness fluctuations
(SBF) distances to candidate dEs known from previous surveys; (2) We
re-assessed morphological classifications for those candidate dEs that are too
faint for SBF detection; and (3) We searched for new candidate dEs in the
size-luminosity regime close to the resolution limit of previous surveys. The
resulting fiducial dE sample follows a well-defined surface brightness -
magnitude relation, showing that Fornax dEs are about 40% larger than Local
Group dEs. The sample also defines a colour-magnitude relation similar to that
of Local Group dEs. The early-type dwarf galaxy luminosity function in Fornax
has a very flat faint end slope alpha = -1.1 +/- 0.1. We compare the number of
dwarfs per unit mass with those in other environments and find that the Fornax
cluster fits well into a general trend of a lack of high-mass dwarfs in more
massive environments.


title:
Spontaneously induced atom-radiation entanglement in an ensemble of
  two-level atoms

abstract:
  Analysis of the spontaneously induced correlation on atom-radiation
entanglement in an ensemble of two-level atoms initially prepared in the upper
level and placed in a cavity containing a squeezed radiation employing the
method of evaluating the coherent-state propagator is presented. It is found
that the cavity radiation exhibits squeezing which is directly attributed to
the squeezed radiation in the cavity. The intensity of the cavity radiation
increases with the squeeze parameter and interaction time. It is also shown
that substantial degree of entanglement between the atomic states and radiation
mode exits at a particular time that depends on the coupling constant and
squeeze parameter. We come to understand that though the squeezed radiation is
directly accountable for the cavity squeezing, it significantly destroys the
atom-radiation entanglement.


title: On the Clausius theorem

abstract:
  We show that for a metastable system there exists a theoretical possibility
of a violation of the Clausius inequality without a violation of the second
law. Possibilities of experimental detection of this hypothetical violation are
pointed out.


title:
Accuracy matrix in generalized simultaneous measurement of a qubit
  system

abstract:
  We formulate the accuracy of quantum measurement for a qubit system in terms
of a 3 by 3 matrix. This matrix, which we refer to as the accuracy matrix, can
be calculated from a positive operator-valued measure (POVM) corresponding to
the quantum measurement. Based on the accuracy matrix, we derive new trade-off
relations between the measurement accuracy of two or three noncommuting
observables of a qubit system. These trade-off relations offer a quantitative
information-theoretic representation of Bohr's principle of complementarity.
They can be interpreted as the uncertainty relations between measurement errors
in simultaneous measurements, and also as the trade-off relations between the
measurement error and back-action of measurement. A no-cloning inequality is
derived from the trade-off relations. Furthermore, our formulation and the
obtained results can be applied to analyze quantum state tomography. We also
show that the accuracy matrix is closely related to the maximum-likelihood
estimation and the Fisher information matrix for a finite number of samples;
the accuracy matrix tells us how accurately we can estimate the probability
distributions of observables of an unknown state by quantum measurement.


title:
Alternative parametrizations and reference priors for decomposable
  discrete graphical models

abstract:
  For a given discrete decomposable graphical model, we identify several
alternative parametrizations, and construct the corresponding reference priors
for suitable groupings of the parameters. Specifically, assuming that the
cliques of the graph are arranged in a perfect order, the parameters we
consider are conditional probabilities of clique-residuals given separators, as
well as generalized log-odds-ratios. We also consider a parametrization
associated to a collection of variables representing a cut for the statistical
model. The reference priors we obtain do not depend on the order of the
groupings, belong to a conjugate family, and are proper.


title: Binary fluids under steady shear in three dimensions

abstract:
  We simulate by lattice Boltzmann the steady shearing of a binary fluid
mixture with full hydrodynamics in three dimensions. Contrary to some
theoretical scenarios, a dynamical steady state is attained with finite
correlation lengths in all three spatial directions. Using large simulations we
obtain at moderately high Reynolds numbers apparent scaling expon ents
comparable to those found by us previously in 2D. However, in 3D there may be a
crossover to different behavior at low Reynolds number: accessing this regime
requires even larger computational resource than used here.


title:
Non-local composite spin-lattice polarons in high temperature
  superconductors

abstract:
  The non-local nature of the polaron formation in t-t'-t"-J model is studied
in large lattices up to 64 sites by developing a new numerical method. We show
that the effect of longer-range hoppings t' and t" is a large anisotropy of the
electron-phonon interaction (EPI) leading to a completely different influence
of EPI on the nodal and antinodal points in agreement with the experiments.
Furthermore, nonlocal EPI preserves polaron's quantum motion, which destroys
the antiferromagnetic order effectively, even at strong coupling regime,
although the quasi-particle weight in angle-resolved-photoemission spectroscopy
is strongly suppressed.


title: Adeles in Mathematical Physics

abstract:
  Application of adeles in modern mathematical physics is briefly reviewed. In
particular, some adelic products are presented.


title: Intrinsic tests for the equality of two correlated proportions

abstract:
  Correlated proportions arise in longitudinal (panel) studies. A typical
example is the ``opinion swing'' problem: ``Has the proportion of people
favoring a politician changed after his recent speech to the nation on TV?''.
Since the same group of individuals is interviewed before and after the speech,
the two proportions are correlated. A natural null hypothesis to be tested is
whether the corresponding population proportions are equal. A standard Bayesian
approach to this problem has already been considered in the literature, based
on a Dirichlet prior for the cell-probabilities of the underlying two-by-two
table under the alternative hypothesis, together with an induced prior under
the null. In lack of specific prior information, a diffuse (e.g. uniform)
distribution may be used. We claim that this approach is not satisfactory,
since in a testing problem one should make sure that the prior under the
alternative be adequately centered around the region specified by the null, in
order to obtain a fair comparison between the two hypotheses. Following an
intrinsic prior methodology, we develop two strategies for the construction of
a collection of objective priors increasingly peaked around the null. We
provide a simple interpretation of their structure in terms of weighted
imaginary sample scenarios. We illustrate our method by means of three
examples, carrying out sensitivity analysis and providing comparison with
existing results.


title: Plotkin construction: rank and kernel

abstract:
  Given two binary codes of length n, using Plotkin construction we obtain a
code of length 2n. The construction works for linear and nonlinear codes. For
the linear case, it is straightforward to see that the dimension of the final
code is the sum of the dimensions of the starting codes. For nonlinear codes,
the rank and the dimension of the kernel are standard mesures of linearity. In
this report, we prove that both parameters are also the sum of the
corresponding ones of the starting codes.


title: Chemical Equilibrium in Collisions of Small Systems

abstract:
  The system-size dependence of particle production in heavy-ion collisions at
the top SPS energy is analyzed in terms of the statistical model. A systematic
comparison is made of two suppression mechanisms that quantify strange particle
yields in ultra-relativistic heavy-ion collisions: the canonical model with
strangeness correlation radius determined from the data and the model
formulated in the canonical ensemble using chemical off-equilibrium strangeness
suppression factor. The system-size dependence of the correlation radius and
the thermal parameters are obtained for p-p, C-C, Si-Si and Pb-Pb collisions at
sqrt(s_NN) = 17.3 AGeV. It is shown that on the basis of a consistent set of
data there is no clear difference between the two suppression patterns. In the
present study the strangeness correlation radius was found to exhibit a rather
weak dependence on the system size.


title:
Progressive field-state collapse and quantum non-demolition photon
  counting

abstract:
  The irreversible evolution of a microscopic system under measurement is a
central feature of quantum theory. From an initial state generally exhibiting
quantum uncertainty in the measured observable, the system is projected into a
state in which this observable becomes precisely known. Its value is random,
with a probability determined by the initial system's state. The evolution
induced by measurement (known as 'state collapse') can be progressive,
accumulating the effects of elementary state changes. Here we report the
observation of such a step-by-step collapse by measuring non-destructively the
photon number of a field stored in a cavity. Atoms behaving as microscopic
clocks cross the cavity successively. By measuring the light-induced
alterations of the clock rate, information is progressively extracted, until
the initially uncertain photon number converges to an integer. The suppression
of the photon number spread is demonstrated by correlations between repeated
measurements. The procedure illustrates all the postulates of quantum
measurement (state collapse, statistical results and repeatability) and should
facilitate studies of non-classical fields trapped in cavities.


title: Some tensor products

abstract:
  We define the tensor product of 1-motives with motives of weight 0 and we
construct explicitely the 1-motive underlying the quotient M_1 \otimes M_2 /
W_{-3}(M_1 \otimes M_2).


title: Dimensionality induced entanglement in macroscopic dimer systems

abstract:
  We investigate entanglement properties of mixtures of short-range spin-s
dimer coverings in lattices of arbitrary topology and dimension. We show that
in one spacial dimension nearest neighbour entanglement exists for any spin
$s$. Surprisingly, in higher spatial dimensions there is a threshold value of
spin $s$ below which the nearest neighbour entanglement disappears. The
traditional "classical" limit of large spin value corresponds to the highest
nearest neighbour entanglement that we quantify using the negativity.


title:
Room temperature Ferromagnetism in Th1-xFexO2-d (x = 0.0, 0.05, 0.10,
  0.15, 0.20 and 0.25) nanoparticles

abstract:
  Nanocrystalline (Th1-xFex)O2-d particles with different Fe concentrations (x
= 0.0, 0.05, 0.10, 0.15, 0.20 and 0.25) have been prepared by a gel combustion
method. Rietveld refinement analyses of X-ray diffraction data revealed the
formation of an impurity free cubic type Th1-xFexO2-d structure up to x = 0.20.
This observation is further confirmed from the detailed studies conducted on 10
at. percent Fe doped ThO2 using high-resolution transmission electron
microscopy (HRTEM) imaging and indexing of the selected-area electron
diffraction (SAED) patterns. DC Magnetization studies as a function field
indicate that they are ferromagnetic with Curie temperature (Tc) well above
room temperature.


title:
Enhanced phase mixing of Alfv\'en waves propagating in stratified and
  divergent coronal structures

abstract:
  Corrected analytical solutions describing the enhanced phase mixing of Alfven
waves propagating in divergent stratified coronal structures are presented.
These show that the enhanced phase mixing mechanism can dissipate Alfven waves
at heights less than half that is predicted by the previous analytical
solutions. The enhanced phase mixing of 0.1 Hz harmonic Alfven waves
propagating in strongly divergent, H_b=5 Mm, stratified coronal structures,
H_rho=50 Mm, can fulfill 100% of an active region heating requirement, by
generating viscous heating fluxes of F_H~2100 J /m^2 /s. The Alfven waves in
this configuration are fully dissipated within 20 Mm, which is six times lower
than would occur as a result of standard phase mixing in uniform magnetic
fields. This results in the heating scale height, s_H, being lowered by a
factor of six, to less than half of an active regions density scale height.
Using the corrected analytical solutions it was found that, for a given wave
frequency, the generation of a heating scale height of s_H<=50 Mm, by enhanced
phase mixing in strongly divergent magnetic fields, requires a shear viscosity
eight orders of magnitude lower, than required by standard phase mixing in
uniform magnetic fields. It was also found that the enhanced phase mixing of
observable, 0.01 rads /s Alfven waves, in strongly divergent magnetic fields,
H_b=5 Mm, can generate heating scale heights within a density scale height,
H_rho=50 Mm, using classical Braginskii viscosity. It is therefore not
necessary to invoke anomalous viscosity in corona, if phase mixing takes place
in strongly divergent magnetic fields. This study shows that the importance of
enhanced phase mixing as a mechanism for dissipating Alfven waves in the solar
corona (a stratified and divergent medium), has been seriously underestimated.


title: Microscopic quantum superpotential in N=1 gauge theories

abstract:
  We consider the N=1 super Yang-Mills theory with gauge group U(N), adjoint
chiral multiplet X and tree-level superpotential Tr W(X). We compute the
quantum effective superpotential W_mic as a function of arbitrary off-shell
boundary conditions at infinity for the scalar field X. This effective
superpotential has a remarkable property: its critical points are in one-to-one
correspondence with the full set of quantum vacua of the theory, providing in
particular a unified picture of solutions with different ranks for the low
energy gauge group. In this sense, W_mic is a good microscopic effective
quantum superpotential for the theory. This property is not shared by other
quantum effective superpotentials commonly used in the literature, like in the
strong coupling approach or the glueball superpotentials. The result of this
paper is a first step in extending Nekrasov's microscopic derivation of the
Seiberg-Witten solution of N=2 super Yang-Mills theories to the realm of N=1
gauge theories.


title: The growth of additive processes

abstract:
  Let $X_t$ be any additive process in $\mathbb{R}^d.$ There are finite indices
$\delta_i, \beta_i, i=1,2$ and a function $u$, all of which are defined in
terms of the characteristics of $X_t$, such that
  \liminf_{t\to0}u(t)^{-1/\eta}X_t^*= \cases{0, \quad if $\eta>\delta_1$,
\cr\infty, \quad if $\eta<\delta_2$,}
  \limsup_{t\to0}u(t)^{-1/\eta}X_t^*= \cases{0, \quad if $\eta>\beta_2$,
\cr\infty, \quad if $\eta<\beta_1$,}\qquad {a.s.},
  where $X_t^*=\sup_{0\le s\le t}|X_s|.$ When $X_t$ is a L\'{e}vy process with
$X_0=0$, $\delta_1=\delta_2$, $\beta_1=\beta_2$ and $u(t)=t.$ This is a special
case obtained by Pruitt. When $X_t$ is not a L\'{e}vy process, its
characteristics are complicated functions of $t$. However, there are
interesting conditions under which $u$ becomes sharp to achieve
$\delta_1=\delta_2$, $\beta_1=\beta_2.$


title:
Finite-size scaling for the left-current correlator with non-degenerate
  quark masses

abstract:
  We study the volume dependence of the left-current correlator with
non-degenerate quark masses to next-to-leading order in the chiral expansion.
We consider three possible regimes: all quark masses are in the
$\epsilon$-regime, all are in the $p$-regime and a mixed-regime where the
lighest quark masses satisfy $m_v \Sigma V \leq 1$ while the heavier $m_s
\Sigma V \gg 1$. These results can be used to match lattice QCD and the Chiral
Effective Theory in a large but finite box in which the Compton wavelength of
the lightest pions is of the order of the box size. We consider both the full
and partially-quenched results.


title: Maximal Arithmetic Progressions in Random Subsets

abstract:
  Let U(N) denote the maximal length of arithmetic progressions in a random
uniform subset of {0,1}^N. By an application of the Chen-Stein method, we show
that U(N)- 2 log(N)/log(2) converges in law to an extreme type (asymmetric)
distribution. The same result holds for the maximal length W(N) of arithmetic
progressions (mod N). When considered in the natural way on a common
probability space, we observe that U(N)/log(N) converges almost surely to
2/log(2), while W(N)/log(N) does not converge almost surely (and in particular,
limsup W(N)/log(N) is at least 3/log(2)).


title:
Analytic application of the mean crossover function to the description
  of the isothermal compressibility of xenon

abstract:
  We use the mean crossover functions [Garrabos and Bervillier, Phys Rev. E 74,
021113 (2006)] estimated from the bounded results of the Massive
Renormalization scheme applied to the $\Phi_{d}^{4}(n)$ model in three
dimensions ($d=3$) and scalar order parameter ($n=1$) [Bagnuls and Bervillier,
Phys. Rev. E 65, 066132 (2002)], to represent the singular behavior of the
isothermal compressibility of xenon along the critical isochore in the
homogeneous preasymptotic domain. The validity range and the Ising nature of
the crossover description are discussed in terms of a single scale factor whose
value can be analytically estimated beyond the Ising-like preasymptotic domain.


title:
Geometrical dependence of decoherence by electronic interactions in a
  GaAs/GaAlAs square network

abstract:
  We investigate weak localization in metallic networks etched in a two
dimensional electron gas between $25\:$mK and $750\:$mK when electron-electron
(e-e) interaction is the dominant phase breaking mechanism. We show that, at
the highest temperatures, the contributions arising from trajectories that wind
around the rings and trajectories that do not are governed by two different
length scales. This is achieved by analyzing separately the envelope and the
oscillating part of the magnetoconductance. For $T\gtrsim0.3\:$K we find
$\Lphi^\mathrm{env}\propto{T}^{-1/3}$ for the envelope, and
$\Lphi^\mathrm{osc}\propto{T}^{-1/2}$ for the oscillations, in agreement with
the prediction for a single ring \cite{LudMir04,TexMon05}. This is the first
experimental confirmation of the geometry dependence of decoherence due to e-e
interaction.


title: Curie temperature of the two band double exchange model for manganites

abstract:
  We consider two-band double exchange model and calculate the critical
temperature in ferromagnetic regime (Curie temperature). The localized spins
are represented in terms of the Schwinger-bosons, and two spin-singlet Fermion
operators are introduced. In terms of the new Fermi fields the on-site Hund's
interactions are in a diagonal form and one accounts for them exactly.
Integrating out the spin-singlet fermions we derive an effective Heisenberg
type model for a vector which describes the local orientations of the total
magnetization. The transversal fluctuations of the vector are the true magnons
in the theory, which is a base for Curie temperature calculation. The critical
temperature is calculated employing the Schwinger-bosons mean-field theory.
While approximate, this technic of calculation captures the essentials of the
magnon fluctuations in the theory, and for 2D systems one obtains zero Curie
temperature, in accordance with Mermin-Wagner theorem.


title:
On elliptic differential operators with shifts: II. The cohomological
  index formula

abstract:
  This paper is a continuation of arXiv:0706.3511, where we obtained a local
index formula for matrix elliptic operators with shifts. Here we establish a
cohomological index formula of Atiyah-Singer type for elliptic differential
operators with shifts acting between section spaces of arbitrary vector
bundles. The key step is the construction of closed graded traces on certain
differential algebras over the symbol algebra for this class of operators.


title:
Jet-induced gauge field instabilities in the quark-gluon plasma: A
  kinetic theory approach

abstract:
  We discuss the properties of the collective modes of a system composed by a
thermalized quark-gluon plasma traversed by a relativistic jet of partons. The
transport equations obeyed by the components of the plasma and of the jet are
studied in the Vlasov approximation. Assuming that the partons in the jet can
be described with a tsunami-like distribution function we derive the
expressions of the dispersion law of the collective modes. Then the behavior of
the unstable gauge modes of the system is analyzed for various values of the
velocity of the jet, of the momentum of the collective modes and of the angle
between these two quantities. We find that the most unstable modes are those
with momentum orthogonal to the velocity of the jet and that these
instabilities appear when the velocity of the jet is higher than a threshold
value, which depends on the plasma and jet frequencies. The results obtained
within the Vlasov approximation are compared with the corresponding results
obtained using a chromohydrodynamical approach.The effect we discuss here
suggests a possible collective mechanism for the description of the jet
quenching phenomena in heavy ion collisions.


title: Manifolds with nonnegative isotropic curvature

abstract:
  We prove that if $(M^n,g)$, $n \ge 4$, is a compact, orientable, locally
irreducible Riemannian manifold with nonnegative isotropic curvature, then one
of the following possibilities hold:
  (i) $M$ admits a metric with positive isotropic curvature
  (ii) $(M,g)$ is isometric to a locally symmetric space
  (iii) $(M,g)$ is K\"ahler and biholomorphic to $\C P^\frac {n}{2}$.
  (iv) $(M,g)$ is quaternionic-K\"ahler.
  This is implied by the following result:
  Let $(M^{2n},g)$ be a compact, locally irreducible K\"ahler manifold with
nonnegative isotropic curvature. Then either $M$ is biholomorphic to $\C P^n$
or isometric to a compact Hermitian symmetric space. This answers a question of
Micallef and Wang in the affirmative.
  The proof is based on the recent work of S. Brendle and R. Schoen on the
Ricci flow.


title: Knot colouring polynomials

abstract:
  This article introduces a natural extension of colouring numbers of knots,
called colouring polynomials, and studies their relationship to Yang-Baxter
invariants and quandle 2-cocycle invariants.
  For a knot K in the 3-sphere let \pi_K be the fundamental group of the knot
complement, and let (m_K,l_K) be a meridian-longitude pair in \pi_K. Given a
finite group G and an element x in G, we consider the set of representations
\rho from \pi_K to G that map the meridian m_K to x, and define the colouring
polynomial P(K) as the sum over all longitude images \rho(l_K). The resulting
invariant maps knots to the group ring Z[G]. It is multiplicative with respect
to connected sum and equivariant with respect to symmetry operations of knots.
Examples are given to show that colouring polynomials distinguish knots for
which other invariants fail, in particular they can distinguish knots from
their mutants, obverses, inverses, or reverses.
  We prove that every quandle 2-cocycle state-sum invariant of knots is a
specialization of some knot colouring polynomial. This provides a complete
topological interpretation of these invariants in terms of the knot group and
its peripheral system. Furthermore, we show that P can be presented as a
Yang-Baxter invariant, i.e. as the trace of some linear braid group
representation. This entails in particular that Yang-Baxter invariants can
detect non-inversible and non-reversible knots.


title:
A Topological Characterization Of Knots and Links Arising From
  Site-Specific Recombination

abstract:
  We develop a topological model of knots and links arising from a single (or
multiple processive) round(s) of recombination starting with an unknot, unlink,
or (2,m)-torus knot or link substrate. We show that all knotted or linked
products fall into a single family, and prove that the size of this family
grows linearly with the cube of the minimum number of crossings. Additionally,
we prove that the only possible products of an unknot substrate are either
clasp knots and links or (2,m)-torus knots and links. Finally, in the (common)
case of (2,m)-torus knot or link substrates whose products have minimal
crossing number m+1, we prove that the types of products are tightly
prescribed, and use this to examine previously uncharacterized experimental
data.


title: Josephson effect through a quantum dot array

abstract:
  We analyze the ground state properties of an array of quantum dots connected
in series between superconducting electrodes. This system is represented by a
finite Hubbard chain coupled at both ends to BCS superconductors. The ground
state is obtained using the Lanczos algorithm within a low energy theory in
which the bulk superconductors are replaced by effective local pairing
potentials. We study the conditions for the inversion of the sign of the
Josephson coupling ($\pi$-junction behavior) as a function of the model
parameters. Results are presented in the form of phase diagrams which provide a
direct overall view of the general trends as the size of the system is
increased, exhibiting a strong even-odd effect. The analysis of the spin-spin
correlation functions and local charges give further insight into the nature of
the ground state and how it is transformed by the presence of superconductivity
in the leads. Finally we study the scaling of the Josephson current with the
system size and relate these results with previous calculations of Josephson
transport through a Luttinger liquid.