title: A Basic Elementary Extension of the Duchet-Meyniel Theorem

abstract:
  The Conjecture of Hadwiger implies that the Hadwiger number $h$ times the
independence number $\alpha$ of a graph is at least the number of vertices $n$
of the graph. In 1982 Duchet and Meyniel proved a weak version of the
inequality, replacing the independence number $\alpha$ by $2\alpha-1$, that is,
$$(2\alpha-1)\cdot h \geq n.$$ In 2005 Kawarabayashi, Plummer and the second
author published an improvement of the theorem, replacing $2\alpha - 1$ by
$2\alpha - 3/2$ when $\alpha$ is at least 3. Since then a further improvement
by Kawarabayashi and Song has been obtained, replacing $2\alpha - 1$ by
$2\alpha - 2$ when $\alpha$ is at least 3.
  In this paper a basic elementary extension of the Theorem of Duchet and
Meyniel is presented. This may be of help to avoid dealing with basic cases
when looking for more substantial improvements. The main unsolved problem (due
to Seymour) is to improve, even just slightly, the theorem of Duchet and
Meyniel in the case when the independence number $\alpha$ is equal to 2. The
case $\alpha = 2$ of Hadwiger's Conjecture was first pointed out by Mader as an
interesting special case.


title: The Identification of New Stellar Groupings in the M81 Debris Field

abstract:
  The stellar content of the debris field around M81 is investigated using deep
images obtained with MegaCam on the Canada-France-Hawaii Telescope. Three new
concentrations of bright main sequence stars and red supergiants are identified
within ~ 20 kpc of M81. These systems have integrated brightnesses M_V ~ -11
and surface brightnesses ~ 27 - 28 mag per arcsec^2 in V. The main sequence
turn-offs are consistent with an age of ~ 30 Myr, while the presence of a
well-developed red supergiant plume indicates that their stellar content is not
coeval, as they also formed stars ~ 100 Myr in the past. The photometric
properties of the red supergiants indicate that the young stars in these
systems have metallicities that are comparable to those of other objects in the
debris field. The HI density near these groupings comfortably exceeds the
threshold required to trigger star formation. Based on the close proximity of
these objects to M81, coupled with their extended sizes and low inferred
masses, it is argued that they will not be long-lived structures, but will
probably dissipate within the next ~ 1 Gyr.


title:
Anisotropic magnetic and superconducting properties of pure and Co-doped
  CaFe$_2$As$_2$ single crystals

abstract:
  We report anisotropic dc magnetic susceptibility $\chi(T)$, electrical
resistivity $\rho(T)$, and heat capacity $C(T)$ measurements on the single
crystals of CaFe$_{2-x}$Co$_x$As$_2$ for $x$ = 0 and 0.06. Large sized single
crystals were grown by the high temperature solution method with Sn as the
solvent. For the pure compound with $x$ = 0, a high temperature transition at
170 K is observed which is attributed to a combined spin density wave (SDW)
ordering and a structural phase transition. On the other hand, for the Co-doped
samples for $x$ = 0.06, the SDW transition is suppressed while
superconductivity is observed at $\simeq$17 K. The superconducting transition
has been confirmed from the magnetization and electrical resistivity studies.
The $^{57}$Fe M\"ossbauer spectrum in CaFe$_2$As$_2$ indicates that the SDW
ordering is incommensurate. In the Co-doped sample, a prominent paramagnetic
line at 4.2 K is observed indicating a weakening of the SDW state.


title:
Representations of finite special linear groups in non-defining
  characteristic

abstract:
  We determine precisely the number of irreducible summands of an irreducible
cross characteristic representation of $GL_{n}(q)$ on restriction to
$SL_{n}(q)$. Combined with a recent result of C. Bonnafe, this yields a
canonical labeling for irreducible $\ell$-modular representations of
$SL_{n}(q)$, where $(\ell,q)=1$. As an application, we classify for the first
time complex representations of $SL_{n}(q)$ whose reductions modulo $\ell$ are
irreducible.


title: Electric Field Driven Magnetic Domain Wall Motion in Iron Garnet Film

abstract:
  The dynamic observation of domain wall motion induced by electric field in
magnetoelectric iron garnet film is reported. Measurements in 800 kV/cm
electric field pulses gave the domain wall velocity ~45 m/s. Similar velocity
was achieved in magnetic field pulse about 50 Oe. Reversible and irreversible
micromagnetic structure transformation is demonstrated. These effects are
promising for applications in spintronics and magnetic memory.


title: On the Topology of Kac-Moody groups

abstract:
  We study the topology of spaces related to Kac-Moody groups. Given a split
Kac-Moody group over the complex numbers, let K denote the unitary form with
maximal torus T having normalizer N(T). In this article we study the cohomology
of the flag manifold K/T, as a module over the Nil-Hecke ring, as well as the
(co)homology of K as a Hopf algebra. In particular, if F is a field of positive
characteristic, we show that H_*(K,F) is a finitely generated algebra, and that
H^*(K,F) is finitely generated only if K is a compact Lie group . We also study
the stable homotopy type of the classifying space BK and show that it is a
retract of the classifying space BN(T). We illustrate our results with the
example of rank two Kac-Moody groups.


title: Evaluation of Authors and Journals

abstract:
  A method is presented for evaluating authors on the basis of citations. It
assigns to each author a citation score which depends upon the number of times
he is cited, and upon the scores of the citers. The scores are found to be the
components of an eigenvector of a normalized citation matrix. The same method
can be applied to citation of journals by other journals, to evaluating teams
in a league [1], etc.


title: Symmetric powers and a problem of Kollar and Larsen

abstract:
  We prove a conjecture of Kollar and Larsen on Zariski closed subgroups of
$GL(V)$ which act irreducibly on some symmetric power $Sym^{k}(V)$ with $k \geq
4$. This conjecture has interesting implications, in particular on the holonomy
group of a stable vector bundle on a smooth projective variety, as shown by the
recent work of Balaji and Kollar.


title:
Spin Glass Transition at Nonzero Temperature in a Disordered Dipolar
  Ising System: The Case of LiHoxY{1-x}F4

abstract:
  The physics of the spin glass (SG) state, with magnetic moments (spins)
frozen in random orientations, is one of the most intriguing problems in
condensed matter physics. While most theoretical studies have focused on the
Edwards-Anderson model of Ising spins with only discrete `up/down' directions,
such Ising systems are experimentally rare. LiHo$_{x}$Y$_{1-x}$F$_{4}$, where
the Ho$^{3+}$ moments are well described by Ising spins, is an almost ideal
Ising SG material. In LiHo$_{x}$Y$_{1-x}$F$_{4}$, the Ho$^{3+}$ moments
interact predominantly via the inherently frustrated magnetostatic
dipole-dipole interactions. The random frustration causing the SG behavior
originates from the random substitution of dipole-coupled Ho$^{3+}$ by
non-magnetic Y$^{3+}$. In this paper, we provide compelling evidence from
extensive computer simulations that a SG transition at nonzero temperature
occurs in a realistic microscopic model of LiHo$_{x}$Y$_{1-x}$F$_{4}$, hence
resolving the long-standing, and still ongoing, controversy about the existence
of a SG transition in disordered dipolar Ising systems.


title:
Hall-Higman type theorems for semisimple elements of finite classical
  groups

abstract:
  We prove an analogue of the celebrated Hall-Higman theorem, which gives a
lower bound for the degree of the minimal polynomial of any semisimple element
of prime power order $p^{a}$ of a finite classical group in any nontrivial
irreducible cross characteristic representation. With a few explicit
exceptions, this degree is at least $p^{a-1}(p-1)$.


title: Pressure-induced structural, electronic, and magnetic effects in BiFeO3

abstract:
  We present a first-principles study of multiferroic BiFeO3 at high pressures.
Our work reveals the main structural (change in Bi's coordination and loss of
ferroelectricity), electronic (spin crossover and metallization), and magnetic
(loss of order) effects favored by compression and how they are connected. Our
results are consistent with the striking manifold transition observed
experimentally by Gavriliuk et al. [Phys. Rev. B 77, 155112 (2008)] and provide
an explanation for it.


title: Finite-Size Scaling behavior in the O(4)-Model

abstract:
  The exact nature of the QCD phase transition has still not been determined
conclusively, and there are contradictory results from lattice QCD simulations
about the scaling behavior for two quark flavors. Ultimately, this issue can be
resolved only by a careful scaling and finite-size scaling analysis of the
lattice results. We use a renormalization group approach to obtain finite-size
scaling functions for the O(4)-model, which are relevant for this analysis. Our
results are applicable to Lattice QCD studies of the QCD phase boundary.


title:
Holomorphic projection and duality for domains in complex projective
  space

abstract:
  We show that the efficiency of a natural pairing between certain projectively
invariant Hardy spaces on dual strongly C-linearly convex real hypersurfaces in
complex projective space is measured by the norm of the corresponding Leray
transform.


title: Spontaneous symmetry breaking in a nonlinear double-well structure

abstract:
  We propose a model of a nonlinear double-well potential (NDWP), alias a
double-well pseudopotential, with the objective to study an alternative
implementation of the spontaneous symmetry breaking (SSB) in Bose-Einstein
condensates (BECs) and optical media, under the action of a potential with two
symmetric minima. In the limit case when the NDWP structure is induced by the
local nonlinearity coefficient represented by a set of two delta-functions, a
fully analytical solution is obtained for symmetric, antisymmetric and
asymmetric states. In this solvable model, the SSB bifurcation has a fully
subcritical character. Numerical analysis, based on both direct simulations and
computation of stability eigenvalues, demonstrates that, while the symmetric
states are stable up to the SSB bifurcation point, both symmetric and emerging
asymmetric states, as well as all antisymmetric ones, are unstable in the model
with the delta-functions. In the general model with a finite width of the
nonlinear-potential wells, the asymmetric states quickly become stable,
simultaneously with the switch of the SSB bifurcation from the subcritical to
supercritical type. Antisymmetric solutions may also get stabilized in the NDWP
structure of the general type, which gives rise to a bistability between them
and asymmetric states. The symmetric states require a finite norm for their
existence, an explanation to which is given. A full diagram for the existence
and stability of the trapped states in the model is produced. Experimental
observation of the predicted effects should be possible in BEC formed by
several hundred atoms.


title: Alignment of the ATLAS barrel muon spectrometer

abstract:
  The muon spectrometer of the ATLAS experiment is one of the largest detectors
ever built. At the LHC, new physics signs could appear through high momentun
muons (1 TeV). Identification and precise momentum measurement of such muons
are two of the main challenges of the ATLAS muon spectrometer. In order to get
a good resolution for high energy muons (i.e. 10% at 1 TeV), the accuracy on
the alignment of precision chambers must be of the order of 50 microns. Several
procedures have been developed to reach such a precision. This document
describes complementary techniques used to align the muon sub-detectors, and
their results : the optical system, the muon cosmic rays and the straight
tracks coming from collisions.


title:
Complex Energy Spectrum and Time Evolution of QBIC States in a
  Two-Channel Quantum wire with an Adatom Impurity

abstract:
  We provide detailed analysis of the complex energy eigenvalue spectrum for a
two-channel quantum wire with an attached adatom impurity. The study is based
on our previous work [Phys. Rev. Lett. 99, 210404 (2007)], in which we
presented the quasi-bound states in continuum (or QBIC states). These are
resonant states with very long lifetimes that form as a result of two
overlapping continuous energy bands one of which, at least, has a divergent van
Hove singularity at the band edge. We provide analysis of the full energy
spectrum for all solutions, including the QBIC states, and obtain an expansion
for the complex eigenvalue of the QBIC state. We show that it has a small decay
rate of the order $g^6$, where $g$ is the coupling constant. As a result of
this expansion, we find that this state is a non-analytic effect resulting from
the van Hove singularity; it cannot be predicted from the ordinary perturbation
analysis that relies on Fermi's golden rule. We will also numerically
demonstrate the time evolution of the QBIC state using the effective potential
method in order to show the stability of the QBIC wave function in comparison
with that of the other eigenstates.


title: A surgery triangle for lattice cohomology

abstract:
  Lattice cohomology, defined by N\'emethi in (arXiv:0709.0841), is an
invariant of negative definite plumbed 3-manifolds which conjecturally computes
the Heegaard Floer homology HF^+. We prove a surgery exact triangle for the
lattice cohomology analogous to the one for HF^+. This is a step towards
comparing these two invariants.


title: Current-Induced Dynamics in Almost Symmetric Magnetic Nanopillars

abstract:
  Magnetic nanodevices usually include a free layer whose configuration can be
changed by spin-polarized current via the spin transfer effect, and a fixed
reference layer. Here, we demonstrate that the roles of the free and the
reference layers interchange over a small range of their relative thicknesses.
Precession of both layers can be induced by spin transfer in symmetric devices,
but the dynamics of one of the layers is rapidly suppressed in asymmetric
devices. We interpret our results in terms of the dynamical coupling between
magnetic layers due to spin transfer.


title: HVS7: a chemically peculiar hyper-velocity star

abstract:
  Context: Hyper-velocity stars are suggested to originate from the dynamical
interaction of binary stars with the supermassive black hole in the Galactic
centre (GC), which accelerates one component of the binary to beyond the
Galactic escape velocity. Aims: The evolutionary status and GC origin of the
HVS SDSS J113312.12+010824.9 (HVS7) is constrained from a detailed study of its
stellar parameters and chemical composition. Methods: High-resolution spectra
of HVS7 obtained with UVES on the ESO VLT were analysed using state-of-the-art
NLTE/LTE modelling techniques that can account for a chemically-peculiar
composition via opacity sampling. Results: Instead of the expected slight
enrichments of alpha-elements and near-solar Fe, huge chemical peculiarities of
all elements are apparent. The He abundance is very low (<1/100 solar), C, N
and O are below the detection limit, i.e they are underabundant (<1/100, <1/3
and <1/10 solar). Heavier elements, however, are overabundant: the iron group
by a factor of ~10, P, Co and Cl by factors ~40, 80 and 440 and rare-earth
elements and Hg even by ~10000. An additional finding, relevant also for other
chemically peculiar stars are the large NLTE effects on abundances of TiII and
FeII (~0.6-0.7dex). The derived abundance pattern of HVS7 is characteristic for
the class of chemical peculiar magnetic B stars on the main sequence. The
chemical composition and high vsini=55+-2km/s render a low mass nature of HVS7
as a blue horizontal branch star unlikely. Conclusions: Such a surface
abundance pattern is caused by atomic diffusion in a possibly magnetically
stabilised, non-convective atmosphere. Hence all chemical information on the
star's place of birth and its evolution has been washed out. High precision
astrometry is the only means to validate a GC origin for HVS7.


title:
Outer-gap vs. Slot-gap Models for Pulsar High Energy Emissions: The Case
  of the Crab Pulsar

abstract:
  We analytically examine the capabilities of rotation-powered pulsars as the
sources of gamma-rays and show that their phase-averaged gamma-ray flux is
proportional to the product of the spin-down flux and the gap trans-field
thickness cubed irrespective of the emission models. Applying the scheme to the
Crab pulsar, we demonstrate that the outer-gap model reproduces the observed
GeV fluxes and that the slot-gap model reproduces at most twenty per cent of
the observed fluxes because of the small trans-field thickness. An implication
on the relationship between the gamma-ray and the spin-down fluxes is
discussed.


title: The enumeration of independent sets on some lattices

abstract:
  In this paper, firstly we show that the entropy constants of the number of
independent sets on certain plane lattices are the same as the entropy
constants of the corresponding cylindrical and toroidal lattices. Secondly, we
consider three more complex lattices which can not be handled by a single
transfer matrix as in the plane quadratic lattice case. By introducing the
concept of transfer multiplicity, we obtain the lower and upper bounds of the
entropy constants of crossed quadratic lattice, generalized aztec diamond
lattice and 8-8-4 lattice.


title:
Morphology Classification and Photometric Redshift Measurement of
  Galaxies

abstract:
  Based on the Sloan Digital Sky Survey Data Release 5 Galaxy Sample, we
explore photometric morphology classification and redshift estimation of
galaxies using photometric data and known spectroscopic redshifts. An
unsupervised method, k-means algorithm, is used to separate the whole galaxy
sample into early- and late-type galaxies. Then we investigate the photometric
redshift measurement with different input patterns by means of artificial
neural networks (ANNs) for the total sample and the two subsamples. The
experimental result indicates that ANNs show better performance when the more
parameters are applied in the training set, and the mixed accuracy
$\sigma_{mix}=\sqrt{{\sigma_{early}}^2+{\sigma_{late}}^2}$ of photometric
redshift estimation for the two subsets is superior to $\sigma_{z}$ for the
overall sample alone. For the optimal result, the rms deviation of photometric
redshifts for the mixed sample amounts to 0.0192, that for the overall sample
is 0.0196, meanwhile, that for early- and late-type galaxies adds up to 0.0164
and 0.0217, respectively.


title: Computing the Distribution of a Tree Metric

abstract:
  The Robinson-Foulds (RF) distance is by far the most widely used measure of
dissimilarity between trees. Although the distribution of these distances has
been investigated for twenty years, an algorithm that is explicitly polynomial
time has yet to be described for computing this distribution (which is also the
distribution of trees around a given tree under the popular Robinson-Foulds
metric). In this paper we derive a polynomial-time algorithm for this
distribution. We show how the distribution can be approximated by a Poisson
distribution determined by the proportion of leaves that lie in `cherries' of
the given tree. We also describe how our results can be used to derive
normalization constants that are required in a recently-proposed maximum
likelihood approach to supertree construction.


title: Upper bound of the fully entangled fraction

abstract:
  We study the fully entangled fraction of quantum states. An upper bound is
obtained for arbitrary dimensional bipartite systems. This bound is shown to be
exact for the case of two-qubit systems. An inequality related the fully
entangled fraction of two qubits in a three-qubit mixed state has been also
presented.


title:
Cognitive Radio with Partial Channel State Information at the
  Transmitter

abstract:
  In this paper, we present the cognitive radio system design with partial
channel state information known at the transmitter (CSIT).We replace the dirty
paper coding (DPC) used in the cognitive radio with full CSIT by the linear
assignment Gel'fand-Pinsker coding (LA-GPC), which can utilize the limited
knowledge of the channel more efficiently. Based on the achievable rate derived
from the LA-GPC, two optimization problems under the fast and slow fading
channels are formulated. We derive semianalytical solutions to find the
relaying ratios and precoding coefficients. The critical observation is that
the complex rate functions in these problems are closely related to ratios of
quadratic form. Simulation results show that the proposed semi-analytical
solutions perform close to the optimal solutions found by brute-force search,
and outperform the systems based on naive DPC. Asymptotic analysis also shows
that these solutions converge to the optimal ones solved with full CSIT when
the K-factor of Rician channel approaches infinity. Moreover, a new coding
scheme is proposed to implement the LA-GPC in practice. Simulation results show
that the proposed practical coding scheme can efficiently reach the theoretical
rate performance.


title: Exploring Confinement with Spin

abstract:
  A confining gauge theory violates the completeness of asymptotic states held
as foundation points of the $S$-matrix. Spin-dependent experiments can yield
results that appear to violate quantum mechanics. The point is illustrated by
violation of the Soffer bound in $QCD$. Experimental confirmation that the
bound is violated would be a discovery of immense importance, sweeping away
fundamental assumptions of strong interaction physics held for the past 50
years.


title: Direct Photons at RHIC

abstract:
  Direct photons are ideal tools to investigate kinematical and thermodynamical
conditions of heavy ion collisions since they are emitted from all stages of
the collision and once produced they leave the interaction region without
further modification by the medium. The PHENIX experiment at RHIC has measured
direct photon production in p+p and Au+Au collisions at 200 GeV over a wide
transverse momentum ($p_T$) range. The $p$ + $p$ measurements allow a
fundamental test of QCD, and serve as a baseline when we try to disentangle
more complex mechanisms producing high $p_T$ direct photons in Au+Au. As for
thermal photons in Au+Au we overcome the difficulties due to the large
background from hadronic decays by measuring "almost real" virtual photons
which appear as low invariant mass $e^+e^-$ pairs: a significant excess of
direct photons is measured above the above next-to-leading order perturbative
quantum chromodynamics calculations. Additional insights on the origin of
direct photons can be gained with the study of the azimuthal anisotropy which
benefits from the increased statistics and reaction plane resolution achieved
in RHIC Year-7 data.


title:
New CTI Correction Method for the Spaced-Row Charge Injection of the
  Suzaku X-Ray Imaging Spectrometer

abstract:
  The charge transfer inefficiency (CTI) of the X-ray CCDs on board the Suzaku
satellite (X-ray Imaging Spectrometers; XIS) has increased since the launch due
to radiation damage, and the energy resolution has been degraded. To improve
the CTI, we have applied a spaced-row charge injection (SCI) technique to the
XIS in orbit; by injecting charges into CCD rows periodically, the CTI is
actively decreased. The CTI in the SCI mode depends on the distance between a
signal charge and a preceding injected row, and the pulse height shows periodic
positional variations. Using in-flight data of onboard calibration sources and
of the strong iron line from the Perseus cluster of galaxies, we studied the
variation in detail. We developed a new method to correct the variation. By
applying the new method, the energy resolution (FWHM) at 5.9 keV at March 2008
is ~155 eV for the front-illuminated CCDs and ~175 eV for the back-illuminated
CCD.


title: Software Engineering & Systems Design Nature

abstract:
  The main problems of Software Engineering appear as a result of
incompatibilities. For example, the quality of organization of the production
process depends on correspondence with existent resources and on a common
understanding of project goals by all team members. Software design is another
example. Its successfulness rides on the architecture's conformity with a
project's concepts. This is a point of great nicety. All elements should create
a single space of interaction. And if the laws of such a space are imperfect,
missequencing comes and the concept of a software system fails. We must do our
best for this not to happen. To that end, having a subtle perception of systems
structures is essential. Such knowledge can be based only on a fresh approach
to the logical law.


title:
A multi-transition molecular line study of inward motions towards
  massive star-forming cores

abstract:
  A multi-transition 3$ $mm molecular line single-pointing and mapping survey
was carried out towards 29 massive star-forming cores in order to search for
the signature of inward motions. Up to seven different transitions, optically
thick lines HCO$^+$(1-0), CS(2-1), HNC(1-0), HCN(1-0), $^{12}$CO(1-0) and
optically thin lines C$^{18}$O(1-0), $^{13}$CO(1-0) were observed towards each
source. The normalized velocity differences ($\delta$V$_{\rm CS}$,
$\delta$V$_{\rm HCO^{+}}$) between the peak velocities of optically thick lines
and optically thin line C$^{18}$O(1-0) for each source were derived. Prominent
inward motions are probably present in either HCO$^+$(1-0) or CS(2-1) or
HNC(1-0) observations in most sources. Our observations show that there is a
significant difference in the incidence of blue shifted line asymmetric line
profiles between CS(2-1) and HCO$^+$(1-0). The HCO$^+$(1-0) shows the highest
occurrence of obvious asymmetric feature, perhaps owing to different optical
depth between CS(2-1) and HCO$^+$(1-0). HCO$^+$(1-0) appears to be the best
inward motion tracer. The mapping observations of multiple line transitions
enable us to identify six strong infall candidates G123.07-6.31, W75(OH),
S235N, CEP-A, W3(OH), NGC7538. The infall signature is extended up to a linear
scale $>0.2 \:$pc.


title: The resonance amplitude associated with the Gamow states

abstract:
  The Gamow states describe the quasinormal modes of quantum systems. It is
shown that the resonance amplitude associated with the Gamow states is given by
the complex delta function. It is also shown that under the near-resonance
approximation of neglecting the lower bound of the energy, such resonance
amplitude becomes the Breit-Wigner amplitude. This result establishes the
precise connection between the Gamow states, Nakanishi's complex delta function
and the Breit-Wigner amplitude. In addition, this result provides another
theoretical basis for the phenomenological fact that the almost-Lorentzian
peaks in cross sections are produced by intermediate, unstable particles.


title:
Bias-Variance Techniques for Monte Carlo Optimization: Cross-validation
  for the CE Method

abstract:
  In this paper, we examine the CE method in the broad context of Monte Carlo
Optimization (MCO) and Parametric Learning (PL), a type of machine learning. A
well-known overarching principle used to improve the performance of many PL
algorithms is the bias-variance tradeoff. This tradeoff has been used to
improve PL algorithms ranging from Monte Carlo estimation of integrals, to
linear estimation, to general statistical estimation. Moreover, as described
by, MCO is very closely related to PL. Owing to this similarity, the
bias-variance tradeoff affects MCO performance, just as it does PL performance.
  In this article, we exploit the bias-variance tradeoff to enhance the
performance of MCO algorithms. We use the technique of cross-validation, a
technique based on the bias-variance tradeoff, to significantly improve the
performance of the Cross Entropy (CE) method, which is an MCO algorithm. In
previous work we have confirmed that other PL techniques improve the perfomance
of other MCO algorithms. We conclude that the many techniques pioneered in PL
could be investigated as ways to improve MCO algorithms in general, and the CE
method in particular.


title:
The effective action and equations of motion of curved local and global
  vortices: Role of the field excitations

abstract:
  The effective actions for both local and global curved vortices are derived,
based on the derivative expansion of the corresponding field theoretic actions
of the nonrelativistic Abelian Higgs and Goldstone models. The role of
excitations of the modulus and the phase of the scalar field and of the gauge
field (the Bogolyubov-Anderson mode) emitted and reabsorbed by vortices is
elucidated. In case of the local (gauge) magnetic vortex, they are necessary
for cancellation of the long distance divergence when using the transverse form
of the electric gauge field strength of the background field. In case of global
vortex taking them into account results in the Greiter-Wilczek-Witten form of
the effective action for the Goldstone mode. The expressions for transverse
Magnus-like force and the vortex effective mass for both local and global
vortices are found. The equations of motion of both type of vortices including
the terms due to the field excitations are obtained and solved in cases of
large and small contour displacements.


title: Bias-Variance Tradeoffs: Novel Applications

abstract:
  We present several applications of the bias-variance decomposition, beginning
with straightforward Monte Carlo estimation of integrals, but progressing to
the more complex problem of Monte Carlo Optimization (MCO), which involves
finding a set of parameters that optimize a parameterized integral. We present
the similarity of this application to that of Parametric Learning (PL).
Algorithms in this field use a particular interpretation of the bias-variance
trade to improve performance. This interpretation also applies to MCO, and
should therefore improve performance. We verify that this is indeed the case
for a particular MCO problem related to adaptive importance sampling.


title:
Genuine Phase Diagram of Homogeneously Doped CuO2 Plane in High-Tc
  Cuprate Superconductors

abstract:
  We report a genuine phase diagram for a disorder-free CuO_2 plane based on
the precise evaluation of the local hole density (N_h) by site-selective Cu-NMR
studies on five-layered high-Tc cuprates. It has been unraveled that (1) the
antiferromagnetic metallic state (AFMM) is robust up to N_h=0.17, (2) the
uniformly mixed phase of superconductivity (SC) and AFMM is realized at N_h<
0.17, (3) the tetracritical point for the AFMM/(AFMM+SC)/SC/PM(Paramagnetism)
phases may be present at N_h=0.15 and T=75 K, (4) Tc is maximum close to a
quantum critical point (QCP) at which the AFM order collapses, suggesting the
intimate relationship between the high-Tc SC and the AFM order. The results
presented here strongly suggest that the AFM interaction plays the vital role
as the glue for the Cooper pairs, which will lead us to a genuine understanding
of why the Tc of cuprate superconductors is so high.


title: The structure of the exponent set for finite cyclic groups

abstract:
  We survey properties of the set of possible exponents of subsets of $\Z_n$
(equivalently, exponents of primitive circulant digraphs on $n$ vertices). Let
$E_n$ denote this exponent set. We point out that $E_n$ contains the positive
integers up to $\sqrt{n}$, the `large' exponents $\lfloor \frac{n}{3} \rfloor
+1, \lfloor \frac{n}{2} \rfloor, n-1$, and for even $n \ge 4$, the additional
value $\frac{n}{2}-1$. It is easy to see that no exponent in
$[\frac{n}{2}+1,n-2]$ is possible, and Wang and Meng have shown that no
exponent in $[\lfloor \frac{n}{3}\rfloor +2,\frac{n}{2}-2]$ is possible.
Extending this result, we show that the interval $[\lfloor \frac{n}{4} \rfloor
+3, \lfloor \frac{n}{3} \rfloor -2]$ is another gap in the exponent set $E_n$.
In particular, $11 \not\in E_{35}$ and this gap is nonempty for all $n \ge 57$.
A conjecture is made about further gaps in $E_n$ for large $n$.


title:
Asymptotic Eigenvalue Moments of Wishart-Type Random Matrix Without
  Ergodicity in One Channel Realization

abstract:
  Consider a random matrix whose variance profile is random. This random matrix
is ergodic in one channel realization if, for each column and row, the
empirical distribution of the squared magnitudes of elements therein converges
to a nonrandom distribution. In this paper, noncrossing partition theory is
employed to derive expressions for several asymptotic eigenvalue moments (AEM)
related quantities of a large Wishart-type random matrix $\bb H\bb H^\dag$ when
$\bb H$ has a random variance profile and is nonergodic in one channel
realization. It is known the empirical eigenvalue moments of $\bb H\bb H^\dag$
are dependent (or independent) on realizations of the variance profile of $\bb
H$ when $\bb H$ is nonergodic (or ergodic) in one channel realization. For
nonergodic $\bb H$, the AEM can be obtained by i) deriving the expression of
AEM in terms of the variance profile of $\bb H$, and then ii) averaging the
derived quantity over the ensemble of variance profiles. Since the AEM are
independent of the variance profile if $\bb H$ is ergodic, the expression
obtained in i) can also serve as the AEM formula for ergodic $\bb H$ when any
realization of variance profile is available.


title: Asymptotic Performance of Linear Receivers in MIMO Fading Channels

abstract:
  Linear receivers are an attractive low-complexity alternative to optimal
processing for multi-antenna MIMO communications. In this paper we characterize
the information-theoretic performance of MIMO linear receivers in two different
asymptotic regimes. For fixed number of antennas, we investigate the limit of
error probability in the high-SNR regime in terms of the Diversity-Multiplexing
Tradeoff (DMT). Following this, we characterize the error probability for fixed
SNR in the regime of large (but finite) number of antennas.
  As far as the DMT is concerned, we report a negative result: we show that
both linear Zero-Forcing (ZF) and linear Minimum Mean-Square Error (MMSE)
receivers achieve the same DMT, which is largely suboptimal even in the case
where outer coding and decoding is performed across the antennas. We also
provide an approximate quantitative analysis of the markedly different behavior
of the MMSE and ZF receivers at finite rate and non-asymptotic SNR, and show
that while the ZF receiver achieves poor diversity at any finite rate, the MMSE
receiver error curve slope flattens out progressively, as the coding rate
increases.
  When SNR is fixed and the number of antennas becomes large, we show that the
mutual information at the output of a MMSE or ZF linear receiver has
fluctuations that converge in distribution to a Gaussian random variable, whose
mean and variance can be characterized in closed form. This analysis extends to
the linear receiver case a well-known result previously obtained for the
optimal receiver. Simulations reveal that the asymptotic analysis captures
accurately the outage behavior of systems even with a moderate number of
antennas.


title:
The impact of accretion disk winds on the X-ray spectrum of AGN: Part 2
  - XSCORT + Hydrodynamic Simulations

abstract:
  abridged: We use XSCORT, together with the hydrodynamic accretion disc wind
simulation from Proga & Kallman (2004), to calculate the impact that the
accretion disk wind has on the X-ray spectrum from a 1E8 solar mass black hole
Active Galactic Nuclei (AGN) accreting at 0.5 L/L_Edd. The properties of the
resulting spectra depend on viewing angle and clearly reflect the distinct
regions apparent in the original hydrodynamic simulation. Very equatorial
lines-of-sight (l.o.s) are dominated by Compton scattering and nearly-neutral
absorption. Polar l.o.s result in largely featureless spectra. Finally, l.o.s
that intersect the transition region between these extremes have a wide range
of absorption features imprinted on the spectrum. Both polar and transition
region l.o.s produce spectra that show highly-ionized, blue-shifted, Fe
absorption features that are qualitatively similar to features observed in the
X-ray spectra of a growing number of AGN. The spectra presented here clearly
demonstrate that current simulations of line driven AGN accretion disk winds
cannot reproduce the smooth soft X-ray excess. Furthermore, they predict that
high accretion rate (L/L_Edd) AGN are likely to be strongly affected by
obscuration, in sharp contrast to the clean picture that is generally assumed,
based on the observed relation between the opening angle of the molecular torus
and AGN luminosity.


title: Asymptotic evaluation of a function defined by power series

abstract:
  We present an asymptotic evaluation unitary formula for large argument values
existing for defined class of functions. The asymptotic evaluation is obtained
using only power series expansion coefficients of a function, what is a new
result in power series analytic continuation theory.


title:
Strong resistance nonlinearity and third harmonic generation in the
  unipolar resistance switching of NiO thin films

abstract:
  We investigated third harmonic generation in NiO thin films, which exhibit
unipolar resistance switching behavior. We found that the low resistance states
of the films were strongly nonlinear, with variations in the resistance R as
large as 60%. This strong nonlinear behavior was most likely caused by Joule
heating of conducting filaments inside the films. By carefully controlling the
applied dc bias, we obtained several low resistance states, whose values of the
third harmonic coefficient B3f were proportional to R2+w (with w = 2.07). This
suggested that the resistance changes of the NiO films were accompanied by
connectivity changes of the conducting filaments, as observed in classical
percolating systems.


title:
Pairing State with a time-reversal symmetry breaking in FeAs based
  superconductors

abstract:
  We investigate the competition between the extended $s_{\pm}$-wave and
$d_{x^2-y^2}$-wave pairing order parameters in the iron-based superconductors.
Because of the frustrating pairing interactions among the electron and the hole
fermi pockets, a time reversal symmetry breaking $s+id$ pairing state could be
favored. We analyze this pairing state within the Ginzburg-Landau theory, and
explore the experimental consequences. In such a state, spatial inhomogeneity
induces supercurrent near a non-magnetic impurity and the corners of a square
sample. The resonance mode between the $s_{\pm}$ and $d_{x^2-y^2}$-wave order
parameters can be detected through the $B_{1g}$-Raman spectroscopy.


title:
On weighted mean matrices whose $l^p$ norms are determined on decreasing
  sequences

abstract:
  We give a condition on weighted mean matrices so that their $l^p$ norms are
determined on decreasing sequences when the condition is satisfied. We apply
our result to give a proof of a conjecture of Bennett and discuss some related
results.


title:
Relating $e^+e^-$ annihilation to high energy scattering at weak and
  strong coupling

abstract:
  We explore the correspondence between the final state in e^+e^- annihilation
and the small-x hadronic wavefunction in the transverse plane both in weakly
coupled QCD and strongly coupled N=4 SYM. At strong coupling, the virtual and
static photon produced in e^+e^- annihilation can be treated as a shock wave
propagating in AdS space leaving spherical energy and charge distributions on
the boundary. This is shown to be mathematically identical to the computation
of energy and charge distributions in the transverse plane generated by a high
energy color singlet state. At weak coupling, the correspondence is useful in
studying interjet observables. By performing the stereographic projection to
the BFKL equation, we construct an exact solution to the evolution equation
derived by Marchesini and Mueller, and find the angular distribution of small-x
gluons in the interjet region. Finally we argue that the correspondence holds
also for the energy correlation functions.


title: Bayesian estimation for selective trace gas detection

abstract:
  We present a Bayesian estimation analysis for a particular trace gas
detection technique with species separation provided by differential diffusion.
The proposed method collects a sample containing multiple gas species into a
common volume, and then allows it to diffuse across a linear array of optical
absorption detectors, using, for example, high-finesse Fabry-Perot cavities.
The estimation procedure assumes that all gas parameters (e.g. diffusion
constants, optical cross sections) are known except for the number population
of each species, which are determined from the time-of-flight absorption
profiles in each detector.


title: Observation of wave turbulence in vibrating plates

abstract:
  The nonlinear interaction of waves in a driven medium may lead to wave
turbulence, a state such that energy is transferred from large to small
lengthscales. Here, wave turbulence is observed in experiments on a vibrating
plate. The frequency power spectra of the normal velocity of the plate may be
rescaled on a single curve, with power-law behaviors that are incompatible with
the weak turbulence theory of D{\"u}ring et al. [Phys. Rev. Lett. 97, 025503
(2006)]. Alternative scenarios are suggested to account for this discrepancy --
in particular the occurrence of wave breaking at high frequencies. Finally, the
statistics of velocity increments do not display an intermittent behavior.


title:
Oxygen abundance in local disk and bulge: chemical evolution with a
  strictly universal IMF

abstract:
  The empirical differential oxygen abundance distribution (EDOD) is deduced
from subsamples related to two different samples involving solar neighbourhood
(SN) thick disk, thin disk, halo, and bulge stars. The EDOD of the SN thick +
thin disk is determined by weighting the mass, for assumed SN thick to thin
disk mass ratio within the range, 0.1-0.9. Inhomogeneous models of chemical
evolution for the SN thick disk, the SN thin disk, the SN thick + thin disk,
the SN halo, and the bulge, are computed assuming the instantaneous recycling
approximation. The EDOD data are fitted, to an acceptable extent, by their TDOD
counterparts provided (i) still undetected, low-oxygen abundance thin disk
stars exist, and (ii) a single oxygen overabundant star is removed from a thin
disk subsample. In any case, the (assumed power-law) stellar initial mass
function (IMF) is universal but gas can be inhibited from, or enhanced in,
forming stars at different rates with respect to a selected reference case.
Models involving a strictly universal IMF (i.e. gas neither inhibited from, nor
enhanced in, forming stars with respect to a selected reference case) can also
reproduce the data. The existence of a strictly universal IMF makes similar
chemical enrichment within active (i.e. undergoing star formation) regions
placed in different environments, but increasing probability of a region being
active passing from SN halo to SN thick + thin disk, SN thin disk, SN thick
disk, and bulge. On the basis of the results, it is realized that the chemical
evolution of the SN thick + thin disk as a whole cannot be excluded.


title: Statistics of power injection in a plate set into chaotic vibration

abstract:
  A vibrating plate is set into a chaotic state of wave turbulence by either a
periodic or a random local forcing. Correlations between the forcing and the
local velocity response of the plate at the forcing point are studied.
Statistical models with fairly good agreement with the experiments are proposed
for each forcing. Both distributions of injected power have a logarithmic cusp
for zero power, while the tails are Gaussian for the periodic driving and
exponential for the random one. The distributions of injected work over long
time intervals are investigated in the framework of the fluctuation theorem,
also known as the Gallavotti-Cohen theorem. It appears that the conclusions of
the theorem are verified only for the periodic, deterministic forcing. Using
independent estimates of the phase space contraction, this result is discussed
in the light of available theoretical framework.


title: Relativistic harmonic oscillator model for quark stars

abstract:
  The relativistic harmonic oscillator (RHO) model of hadrons is used to study
quark stars. The mass-radius relationship is obtained and compared with bag
model of quark star, using Tolman-Oppenheimer-Volkoff equation. In this model,
the outward degenerate pressure due to discrete Landau levels and Landau
degeneracy balances the inward gravitational pressure. Where as in bag model
the degenerate pressure is due to the standard continuum levels which balances
the combined inward pressure due to gravitation and bag pressure. So in RHO
model, the confinement effect is included in the degenerate pressure. We found
a qualitative similarity, but quantitative differences in mass-radius
relationship of quark stars in these two models. Masses and radii are
relatively larger and the central energy densities, required for stable quark
stars, are lower in RHO model than that of bag model.


title:
Numerical upscaling of the permeability of a randomly cracked porous
  medium

abstract:
  The equivalent permeability of a randomly cracked porous material is studied
using a finite element program in which a four-nodes zero-thickness element is
implemented for modelling the cracks. The numerical simulations are performed
for geometries with different cracks densities and for different values of
matrix permeability and cracks conductivity, but the cracks length are taken
equal to one. The method used for determination of the equivalent permeability
resulted in a perfectly symmetric equivalent permeability tensor for each case.
Based on the obtained results a simple relation is presented for the equivalent
permeability of a randomly cracked porous material as a function of the matrix
permeability and the cracks density and conductivity. This relation is then
generalized for the cracks of any length using a linear transformation.


title:
HIV with contact-tracing: a case study in Approximate Bayesian
  Computation

abstract:
  Missing data is a recurrent issue in epidemiology where the infection process
may be partially observed. Approximate Bayesian Computation, an alternative to
data imputation methods such as Markov Chain Monte Carlo integration, is
proposed for making inference in epidemiological models. It is a
likelihood-free method that relies exclusively on numerical simulations. ABC
consists in computing a distance between simulated and observed summary
statistics and weighting the simulations according to this distance. We propose
an original extension of ABC to path-valued summary statistics, corresponding
to the cumulated number of detections as a function of time. For a standard
compartmental model with Suceptible, Infectious and Recovered individuals
(SIR), we show that the posterior distributions obtained with ABC and MCMC are
similar. In a refined SIR model well-suited to the HIV contact-tracing data in
Cuba, we perform a comparison between ABC with full and binned detection times.
For the Cuban data, we evaluate the efficiency of the detection system and
predict the evolution of the HIV-AIDS disease. In particular, the percentage of
undetected infectious individuals is found to be of the order of 40%.


title:
Correlation between two quasilinear elliptic problems with a source term
  involving the function or its gradient

abstract:
  Thanks to a change of unknown we compare two elliptic quasilinear problems
with Dirichlet data in a bounded domain of $\mathbb{R}^{N}.$ The first one, of
the form $-\Delta_{p}u=\beta(u)| \nabla u| ^{p}+\lambda f(x),$ where $\beta$ is
nonnegative, involves a gradient term with natural growth. The second one, of
the form $-\Delta_{p}v=\lambda f(x)(1+g(v))^{p-1}$ where $g$ is nondecreasing,
presents a source term of order 0. The correlation gives new results of
existence, nonexistence and multiplicity for the two problems.


title:
Standard(-like) Model from an SO(12) Grand Unified Theory in
  six-dimensions with $S_2$ extra-space

abstract:
  We analyze a gauge-Higgs unification model which is based on a gauge theory
defined on a six-dimensional spacetime with an $S^2$ extra-space. We impose a
symmetry condition for a gauge field and non-trivial boundary conditions of the
$S^2$. We provide the scheme for constructing a four-dimensional theory from
the six-dimensional gauge theory under these conditions. We then construct a
concrete model based on an SO(12) gauge theory with fermions which lie in a 32
representation of SO(12), under the scheme. This model leads to a
Standard-Model(-like) gauge theory which has gauge symmetry SU(3) $\times$
SU(2)$_L$ $\times$ U(1)$_Y$($\times$ U(1)$^2$) and one generation of SM
fermions, in four-dimensions. The Higgs sector of the model is also analyzed,
and it is shown that the electroweak symmetry breaking and the prediction of
W-boson and Higgs-boson masses are obtained.


title:
Dual condensate, dressed Polyakov loops and center symmetry from Dirac
  spectra

abstract:
  We construct a novel observable for finite temperature QCD that relates
confinement and chiral symmetry. It uses phases as boundary conditions for the
fermions. We discuss numerical and analytical aspects of this observable, like
its spectral behavior below and above the critical temperature, as well as the
connection to chiral condensate, center symmetry and the canonical ensemble.


title:
Supersolid Order of Frustrated Hard-Core Bosons in a Triangular Lattice
  System

abstract:
  We numerically demonstrate that a supersolid phase exists in a frustrated
hard-core boson system on a triangular lattice over a wide range of interaction
strength. In the infinite repulsion (Ising) limit, we establish a mapping to
the same problem with unfrustrated hopping, which connects the supersolid to
the known results in that case. The weak superfluidity can be destroyed or
strongly enhanced by a next nearest neighbor hopping term, which provides
valuable information for experimental realization of a supersolid phase on
optical lattice.


title:
Large Scale Variational Inference and Experimental Design for Sparse
  Generalized Linear Models

abstract:
  Many problems of low-level computer vision and image processing, such as
denoising, deconvolution, tomographic reconstruction or super-resolution, can
be addressed by maximizing the posterior distribution of a sparse linear model
(SLM). We show how higher-order Bayesian decision-making problems, such as
optimizing image acquisition in magnetic resonance scanners, can be addressed
by querying the SLM posterior covariance, unrelated to the density's mode. We
propose a scalable algorithmic framework, with which SLM posteriors over full,
high-resolution images can be approximated for the first time, solving a
variational optimization problem which is convex iff posterior mode finding is
convex. These methods successfully drive the optimization of sampling
trajectories for real-world magnetic resonance imaging through Bayesian
experimental design, which has not been attempted before. Our methodology
provides new insight into similarities and differences between sparse
reconstruction and approximate Bayesian inference, and has important
implications for compressive sensing of real-world images.


title:
A Hamiltonian action of the Schr\"odinger-Virasoro algebra on a space of
  periodic time-dependent Schr\"odinger operators in $(1+1)$-dimensions

abstract:
  Let ${\cal S}^{lin}:=\{a(t)(-2\II \partial_t-\partial_r^2+V(t,r) | a\in
C^{\infty}(\R/2\pi\Z),
  V\in C^{\infty}(\R/2\pi\Z\times\R)\}$ be the space of Schr\"odinger operators
in $(1+1)$-dimensions with periodic time-dependent potential. The action on
${\cal S}^{lin}$ of a large infinite-dimensional reparametrization group $SV$
with Lie algebra $\sv$ \cite{RogUnt06,Unt08}, called the Schr\"odinger-Virasoro
group and containing the Virasoro group, is proved to be Hamiltonian for a
certain Poisson structure on ${\cal S}^{lin}$. More precisely, the
infinitesimal action of $\sv$ appears to be part of a coadjoint action of a Lie
algebra of pseudo-differential symbols, $\g$, of which $\sv$ is a quotient,
while the Poisson structure is inherited from the corresponding
Kirillov-Kostant-Souriau form.


title: Stationary Light Pulses without Bragg Gratings

abstract:
  The underlying mechanism of the stationary light pulse (SLP) was identified
as a band gap being created by a Bragg grating formed by two
counter-propagating coupling fields of similar wavelength. Here we present a
more general view of the formation of SLPs, namely several balanced four-wave
mixing processes sharing the same ground-state coherence. Utilizing this new
concept we report the first experimental observation of a bichromatic SLP at
wavelengths for which no Bragg grating can be established. We also demonstrate
the production of a SLP directly from a propagating light pulse without prior
storage. Being easily controlled externally makes SLPs a very versatile tool
for low-light-level nonlinear optics and quantum information manipulation.


title:
Superconducting/ferromagnetic diffusive bilayer with a spin-active
  interface: a numerical study

abstract:
  We calculate the density of states (DOS) in a diffusive
superconducting/ferromagnetic bilayer with a spin-active interface. We use a
self-consistent numerical treatment to make a systematic study of the effects
of the Spin-Dependence of Interfacial Phase Shifts (SDIPS) on the
self-consistent superconducting gap and the DOS. Strikingly, we find that the
SDIPS can induce a double gap structure (DGS) in the DOS of the ferromagnet,
even when the superconducing layer is much thicker than the superconducting
coherence lenght. We thus obtain DOS curves which have interesting similarities
with those of Phys. Rev. Lett. 100, 237002 (2008).


title: Empirical relationship as a stepping-stone to theory

abstract:
  We consider parsimonious construction of empirical equations, to promote
interest in them as a stepping-stone model to the physical law. To this end, we
provide a variety of historical examples and simulate a parsimonious empirical
calculation of Planck law, and of van der Waals equation. Thereby we provide a)
Empirical forms of Planck law, and b) Collation of verified symmetries and
catastrophes-like properties of empirical P-T surface of real gases. An
empirical equation of state for a real gas should take account of these
properties.


title: A linear time algorithm for L(2,1)-labeling of trees

abstract:
  An L(2,1)-labeling of a graph $G$ is an assignment $f$ from the vertex set
$V(G)$ to the set of nonnegative integers such that $|f(x)-f(y)|\ge 2$ if $x$
and $y$ are adjacent and $|f(x)-f(y)|\ge 1$ if $x$ and $y$ are at distance 2,
for all $x$ and $y$ in $V(G)$. A $k$-L(2,1)-labeling is an assignment
$f:V(G)\to\{0,..., k\}$, and the L(2,1)-labeling problem asks the minimum $k$,
which we denote by $\lambda(G)$, among all possible assignments. It is known
that this problem is NP-hard even for graphs of treewidth 2, and tree is one of
a very few classes for which the problem is polynomially solvable. The running
time of the best known algorithm for trees had been $\mO(\Delta^{4.5} n)$ for
more than a decade, however, an $\mO(n^{1.75})$-time algorithm has been
proposed recently, which substantially improved the previous one, where
$\Delta$ is the maximum degree of $T$ and $n=|V(T)|$. In this paper, we finally
establish a linear time algorithm for L(2,1)-labeling of trees.


title: Top Quark Mass from CDF

abstract:
  This letter presents results on the precision measurement of the top quark
mass and a combination of the best CDF top mass measurements. A combination by
the TevEWWG (Tevatron electroweak working group) of the best top mass results
from CDF and D0 in Run 1 and Run 2 of the Tevatron is also presented. This
result is the current world average, and offers an uncertainty less than 1%.
The new mass value has been included in traditional LEP EWWG fits to precision
electroweak data, and implications for the Standard Model Higgs have been
derived.


title: Spinning Electroweak Sphalerons

abstract:
  We present numerical evidence for the existence of stationary spinning
generalizations for the static sphaleron in the Weinberg-Salam theory. Our
results suggest that, for any value of the mixing angle $\thetw$ and for any
Higgs mass, the spinning sphalerons comprise a family labeled by their angular
momentum $J$. For $\thetw\neq 0$ they possess an electric charge $Q=eJ$ where
$e$ is the electron charge. Inside they contain a monopole-antimonopole pair
and a spinning loop of electric current, and for large $J$ they show a
Regge-type behavior. It is likely that these sphalerons mediate the topological
transitions in sectors with $J\neq 0$, thus enlarging the number of transition
channels. Their action {\it decreases} with $J$, which may considerably affect
the total transition rate.


title: Ultrarelativistic Electron-Positron Plasma

abstract:
  Ultrarelativistic electron-positron plasmas can be produced in high-intensity
laser fields and play a role in various astrophysical situations. Their
properties can be calculated using QED at finite temperature. Here we will use
perturbative QED at finite temperature for calculating various important
properties, such as the equation of state, dispersion relations of collective
plasma modes of photons and electrons, Debye screening, damping rates, mean
free paths, collision times, transport coefficients, and particle production
rates, of ultrarelativistic electron-positron plasmas. In particular, we will
focus on electron-positron plasmas produced with ultra-strong lasers.


title: Chiral Crystal Growth under Grinding

abstract:
  To study the establishment of homochirality observed in the crystal growth
experiment of chiral molecules from a solution under grinding, we extend the
lattice gas model of crystal growth as follows. A lattice site can be occupied
by a chiral molecule in R or S form, or can be empty. Molecules form
homoclusters by nearest neighbor bonds. They change their chirality if they are
isolated monomers in the solution. Grinding is incorporated by cutting and
shafling the system randomly. It is shown that Ostwald ripening without
grinding is extremely slow to select chirality, if possible. Grinding alone
also cannot achieve chirality selection. For the accomplishment of
homochirality, we need an enhanced chirality change on crystalline surface.
With this "autocatalytic effect" and the recycling of monomers due to rinding,
an exponential increase of crystal enantiomeric excess to homochiral state is
realized.


title: A Note on Maximal Averages in the Plane

abstract:
  Using variants of the TT* method we give a self-contained proof of the result
of Alfonseca, Soria and Vargas on maximal operators on arbitrary directions in
$\rr^2$. We also give a sharp $L^2$ estimate for a maximal function extending a
Theorem of Cordoba.


title: Supernova 2008D: A Repetition of Supernova 1987A In a Binary

abstract:
  The Supernova 2008D is similar to that of SN 1987A without the H-envelope.
Soderberg et al.(2008) reported the serendipitous discovery of the SN2008D at
the time of the explosion, accompanied by an X-ray outburst XRF080109. The
central remnant, which we believe to be the black-hole (BH) central engine in
the Blandford-Znajek mechanism, is estimated, on the basis of the 7% 56Ni
production, to have a mass of 1.6-1.8 M_sun. This is not much larger than the
upper limit of 1.56 m_sun for the mass of the compact object in SN1987A found
by Bethe & Brown (1995); also, on the basis of the 7.5% 56Ni production, they
interpreted it as a low-mass BH. Redoing the light curve so as to take into
account the absence of convective carbon burning from zero age main sequence
18-24 M_sun and replacing it by carbon shell burning, we see that the remnant
in SN2008D must be less massive than in SN 1987A; there of 18 M_sun. Thus, the
maximum neutron star mass is 1.5 M_sun. Note that the metallicity of the host
galaxy of SN2008D is similar to that of our Galaxy.


title:
Correlations between sneutrino oscillations and signatures at the LHC in
  anomaly-mediated supersymmetry breaking

abstract:
  Sneutrino-antisneutrino oscillation can be observed at the LHC by studying a
charge asymmetry of the leptons in the final states. We demonstrate this in the
context of an anomaly-mediated supersymmetry breaking model which can give rise
to a large oscillation probability. The preferred region of the parameter space
is characterized by the presence of a sneutrino next-to-lightest supersymmetric
particle and a stau lightest supersymmetric particle. We show that the signals
studied here have certain correlations with the pattern of the sneutrino
oscillation.


title:
Probability models characterized by generalized reversed lack of memory
  property

abstract:
  A binary operator * over real numbers is said to be associative if
$(x*y)*z=x*(y*z)$ and is said to be reducible if $x*y=x*z$ or $y*w=z*w$ if and
only if $z=y$. The operation is said to have an identity element $\tilde{e}$ if
$x*\tilde{e}=x$. In this paper a characterization of a subclass of the reversed
generalized Pareto distribution (Castillo and Hadi (1995)) in terms of the
reversed lack of memory property (Asha and Rejeesh (2007)) is generalized using
this binary operation and probability distributions are characterized using the
same. This idea is further generalized to the bivariate case.


title: Low dimensional discriminant loci and scrolls

abstract:
  Smooth complex polarized varieties $(X,L)$ with a vector subspace $V
\subseteq H^0(X,L)$ spanning $L$ are classified under the assumption that the
locus ${\Cal D}(X,V)$ of singular elements of $|V|$ has codimension equal to
$\dim(X)-i$, $i=3,4,5$, the last case under the additional assumption that $X$
has Picard number one. In fact it is proven that this codimension cannot be
$\dim(X)-4$ while it is $\dim(X)-3$ if and only if $(X,L)$ is a scroll over a
smooth curve. When the codimension is $\dim(X)-5$ and the Picard number is one
only the Pl\"ucker embedding of the Grassmannian of lines in $\Bbb P^4$ or one
of its hyperplane sections appear. One of the main ingredients is the
computation of the top Chern class of the first jet bundle of scrolls and
hyperquadric fibrations. Further consequences of these computations are also
provided.


title:
A Simple Determination of the (LOGARITHMIC) Corrections of Black Hole
  Entropy "without Knowing the Details of Quantum Gravity"

abstract:
  In this work, starting by simple, approximate (quasi-classical) methods
presented in our previous works, we suggest a simple determination of the
(logarithmic) corrections of (Schwarzschild) black hole entropy "without
knowing the details of quantum gravity"(Fursaev). Namely, in our previous works
we demonstrated that all well-known important thermodynamical characteristics
of the black hole (Bekenstein-Hawking entropy, Bekenstein entropy/surface
quantization and Hawking temperature) can be effectively reproduced starting by
simple supposition that black hole horizon circumference holds integer number
of reduced Compton wave lengths corresponding to mass (energy) spectrum of a
small quantum system. (Obviously it is conceptually analogous to Bohr
quantization postulate interpreted by de Broglie relation in Old,
Bohr-Sommerfeld, quantum theory.) Especially, black hole entropy can be
presented as the quotient of the black hole mass and the minimal mass of small
quantum system in ground mass (energy) state. Now, we suppose that black hole
mass correction is simply equivalent to negative classical potential energy of
the gravitational interaction between black hole and small quantum system in
ground mass (energy) state. As it is not hard to see absolute value of the
classical potential energy of gravitational interaction is identical to black
hole temperature. All this, according to first thermodynamical law, implies
that first order entropy correction holds form of the logarithm of the surface
with coefficient -0.5. Our result, obtained practically quasi-classically,
"without knowing the details of quantum gravity", is equivalent to result
obtained by loop quantum gravity and other quantum gravity methods for
macroscopic black holes.


title: Hedging and production decisions under uncertainty: A survey

abstract:
  This paper synthesizes and analyzes some important current and recent
contributions to the theory of the firm under uncertainty. In so doing, it
examines the production and hedging decisions of the competitive firm under a
single source and multiple sources of uncertainty.


title: Obscuring clouds playing hide-and-seek in the Active Nucleus H0557-385

abstract:
  This paper reports on two XMM-Newton observations of the Seyfert 1 Galaxy
H0557-385 obtained in 2006, which show the source at an historical low flux
state, more than a factor of 10 lower than a previous XMM-Newton look in 2002.
The low flux spectrum presents a strong Fe Kalpha line associated to a Compton
reflection continuum. An additional spectral line around 6.6 keV is required to
fit Kalpha emission from Fe XXV. The spectral curvature below 6 keV implies
obscuration by neutral gas with a column density of 8*10^{23}cm^{-2} partially
covering the primary emission, which still contributes for a few percent of the
soft X-ray emission. Absorption by ionised material on the line of sight is
required to fit the deep trough below 1 keV. The comparison of the two spectral
states shows that the flux transition is to be ascribed entirely to intervening
line-of-sight clouds with high column density.


title:
Transiting exoplanets from the CoRoT space mission VI. CoRoT-Exo-3b: The
  first secure inhabitant of the brown-dwarf desert

abstract:
  Context. The CoRoT space mission routinely provides high-precision
photometric measurements of thousands of stars that have been continuously
observed for months.
  Aims. The discovery and characterization of the first very massive transiting
planetary companion with a short orbital period is reported.
  Methods. A series of 34 transits was detected in the CoRoT light curve of an
F3V star, observed from May to October 2007 for 152 days. The radius was
accurately determined and the mass derived for this new transiting, thanks to
the combined analysis of the light curve and complementary ground-based
observations: high-precision radial-velocity measurements, on-off photometry,
and high signal-to-noise spectroscopic observations.
  Results. CoRoT-Exo-3b has a radius of 1.01+-0.07 RJup and transits around its
F3-type primary every 4.26 days in a synchronous orbit. Its mass of 21.66+-1.0
MJup, density of 26.4+-5.6 g cm^-3, and surface gravity of log g = 4.72 clearly
distinguish it from the regular close-in planet population, making it the most
intriguing transiting substellar object discovered so far.
  Conclusions. With the current data, the nature of CoRoT-Exo-3b is ambiguous,
as it could either be a low-mass brown-dwarf or a member of a new class of
"superplanets". Its discovery may help constrain the evolution of close-in
planets and brown-dwarfs better. Finally, CoRoT-Exo-3b confirms the trend that
massive transiting giant planets (M >= 4 MJup) are found preferentially around
more massive stars than the Sun.


title: From time series to complex networks: the visibility graph

abstract:
  In this work we present a simple and fast computational method, the
visibility algorithm, that converts a time series into a graph. The constructed
graph inherits several properties of the series in its structure. Thereby,
periodic series convert into regular graphs, and random series do so into
random graphs. Moreover, fractal series convert into scale-free networks,
enhancing the fact that power law degree distributions are related to
fractality, something highly discussed recently. Some remarkable examples and
analytical tools are outlined in order to test the method's reliability. Many
different measures, recently developed in the complex network theory, could by
means of this new approach characterize time series from a new point of view.


title: Rare B decays with moving NRQCD and improved staggered quarks

abstract:
  We calculate form factors relevant for rare B decays using moving-NRQCD for
the b quark and the AsqTad action for the light quarks. Moving NRQCD allows us
to work directly with the physical b quark mass and go to higher recoil
momentum compared to standard NRQCD. Here, we show first results for the matrix
elements and the operator matching coefficients. Some difficulties and possible
ways of improvement are discussed.


title: Soft-Photons and the entanglement of charged qubtis

abstract:
  In this work, I consider the effect of the unavoidable presence of
soft-photons on the spin entanglement of charged qubits, arguing that the spin
entanglement is not modified if we consider the effects of the infrared
structure of QED on it.


title: Dynamics of black holes

abstract:
  This is a review of current theory of black-hole dynamics, concentrating on
the framework in terms of trapping horizons. Summaries are given of the
history, the classical theory of black holes, the defining ideas of dynamical
black holes, the basic laws, conservation laws for energy and angular momentum,
other physical quantities and the limit of local equilibrium. Some new material
concerns how processes such as black-hole evaporation and coalescence might be
described by a single trapping horizon which manifests temporally as separate
horizons.


title: The Neron model over the Igusa curves

abstract:
  We analyze the geometry of rational p-division points in degenerating
families of elliptic curves in characteristic p. We classify the possible
Kodaira symbols and determine for the Igusa moduli problem the reduction type
of the universal curve. Special attention is paid to characteristic 2 and 3
where wild ramification and stacky phenomena show up.


title: Charge distribution and radii in clusters from nuclear pasta models

abstract:
  We study the consistency of the description of charge distributions and radii
of nuclear clusters obtained with semiclassical nuclear pasta models. These
nuclei are expected to exist in the low density outer crust of neutron stars.
Properties of the arising clusterized nucleon matter can be compared to
realistic nuclear properties as experimentally extracted on earth. We focus on
non iso-symmetric light clusters with nucleon number $8 \le A \le 30$ and use
Monte Carlo many-body techniques. We simulate isotopic chains for a set of
selected nuclei using a model Hamiltonian consisting of the usual kinetic term,
hadronic nucleon nucleon (NN), Coulomb and an effective density dependent Pauli
potential. It is shown that for neutron rich (deficient) clusters neutron
(proton) skins develop. Different (matter, neutron, proton, electric charge)
radii are computed for this set of non iso-symmetric nuclei. Nuclear binding
energies are also analyzed in the isotopic chains.


title:
Transport and localization in periodic and disordered graphene
  superlattices

abstract:
  We study charge transport in one-dimensional graphene superlattices created
by applying layered periodic and disordered potentials. It is shown that the
transport and spectral properties of such structures are strongly anisotropic.
In the direction perpendicular to the layers, the eigenstates in a disordered
sample are delocalized for all energies and provide a minimal non-zero
conductivity, which cannot be destroyed by disorder, no matter how strong this
is. However, along with extended states, there exist discrete sets of angles
and energies with exponentially localized eigenfunctions (disorder-induced
resonances). It is shown that, depending on the type of the unperturbed system,
the disorder could either suppress or enhance the transmission. Most remarkable
properties of the transmission have been found in graphene systems built of
alternating p-n and n-p junctions. This transmission has anomalously narrow
angular spectrum and, surprisingly, in some range of directions it is
practically independent of the amplitude of fluctuations of the potential.
Owing to these features, such samples could be used as building blocks in
tunable electronic circuits. To better understand the physical implications of
the results presented here, most of our results have been contrasted with those
for analogous wave systems. Along with similarities, a number of quite
surprising differences have been found.


title:
Astronomical site selection: On the use of satellite data for aerosol
  content monitoring

abstract:
  The main goal of this work is the analysis of new approaches to the study of
the properties of astronomical sites. In particular, satellite data measuring
aerosols have recently been proposed as a useful technique for site
characterization and searching for new sites to host future very large
telescopes. Nevertheless, these data need to be critically considered and
interpreted in accordance with the spatial resolution and spectroscopic
channels used. In this paper we have explored and retrieved measurements from
satellites with high spatial and temporal resolutions and concentrated on
channels of astronomical interest. The selected datasets are OMI on board the
NASA Aura satellite and MODIS on board the NASA Terra and Aqua satellites. A
comparison of remote sensing and in situ techniques is discussed. As a result,
we find that aerosol data provided by satellites up to now are not reliable
enough for aerosol site characterization, and in situ data are required.


title:
Thermodynamical Characteristics of "Crystal Lattice" of Many Interacting
  Kerr Black Holes in Touching Limit

abstract:
  In this work, starting by simple, approximate (quasi-classical) methods
presented in our previous works, we reproduce effectively and generalize final
results of Herdeiro and Rebelo on the basic thermodynamical characteristics
(entropy and temperature) of two interacting Kerr black holes (in touching
limit) obtained recently by accurate analysis. Like as it has been done in our
previous works, we simply suppose that circumference of the horizon of total
black hole (that includes two or, generally, a "crystal lattice" of many
interacting Kerr black holes in touching limit, without angular momentum) holds
integer number of reduced Compton wave lengths corresponding to mass spectrum
of a small quantum system captured at horizon. (Obviously it is conceptually
analogous to Bohr quantization postulate interpreted by de Broglie relation in
Old, Bohr-Sommerfeld, quantum theory.) It, by simple mathematical methods,
first neighbour approximation of the black holes interaction and first
thermodynamical law, implies mentioned basic thermodinamical characteristic of
the total black hole as well as any its part, i.e. single black hole.
Especially, it is shown that, in limit of increasing number of the black holes,
entropy and horizon surface of the total black hole stand observables of the
discrete spectrum while entropy and horizon surface of the single black hole
tends toward observables of the continuous spectrum.


title:
Spin polarized current and Andreev transmission in planar
  superconducting/ferromagnetic Nb/Ni junctions

abstract:
  We have measured the tunnelling current in Nb/Nb$_x$O$_y$/Ni planar tunnel
junctions at different temperatures. The junctions are in the intermediate
transparency regime. We have extracted the current polarization of the
metal/ferromagnet junction without applying a magnetic field. We have used a
simple theoretical model, that provides consistent fitting parameters for the
whole range of temperatures analyzed. We have also been able to gain insight
into the microscopic structure of the oxide barriers of our junctions.%


title:
Hirota's virtual multi-soliton solutions of N=2 supersymmetric
  Korteweg-de Vries equations

abstract:
  We prove that Mathieu's N=2 supersymmetric Korteweg-de Vries equations with
a=1 or a=4 admit Hirota's n-supersoliton solutions, whose nonlinear interaction
does not produce any phase shifts. For initial profiles that can not be
distinguished from a one-soliton solution at times t<<0, we reveal the
possibility of a spontaneous decay and, within a finite time, transformation
into a solitonic solution with a different wave number. This paradoxal effect
is realized by the completely integrable N=2 super-KdV systems, whenever the
initial soliton is loaded with other solitons that are virtual and become
manifest through the tau-function as the time grows.
  Key words and phrases: Hirota's solitons, N=2 supersymmetric KdV,
Krasil'shchik-Kersten system, phase shift, spontaneous decay.


title: Star Formation in the Rosette Complex

abstract:
  The Rosette Complex in the constellation of Monoceros is a magnificent
laboratory for the study of star formation. The region presents an interesting
scenario, in which an expanding HII region generated by the large OB
association NGC 2244 is interacting with a giant molecular cloud. Inside the
cloud a number of stellar clusters have formed recently. In this chapter we
present a review of past and present research on the region, and discuss
investigations relevant to the physics of the nebula and the molecular cloud.
We also review recent work on the younger embedded clusters and individual
nebulous objects located across this important star forming region.


title: Multiparameter entangled state engineering using adaptive optics

abstract:
  We investigate how quantum coincidence interferometry is affected by a
controllable manipulation of transverse wave-vectors in type-II parametric down
conversion using adaptive optics techniques. In particular, we discuss the
possibility of spatial walk-off compensation in quantum interferometry and a
new effect of even-order spatial aberration cancellation.


title: On nowhere continuous Costas functions and infinite Golomb rulers

abstract:
  We prove the existence of nowhere continuous bijections that satisfy the
Costas property, as well as (countably and uncountably) infinite Golomb rulers.
We define and prove the existence of real and rational Costas clouds, namely
nowhere continuous Costas injections whose graphs are everywhere dense in a
region of the real plane, based on nonlinear solutions of Cauchy's functional
equation. We also give 2 constructive examples of a nowhere continuous
function, that satisfies a constrained form of the Costas property (over
rational or algebraic displacements only, that is), based on the indicator
function of a dense subset of the reals.


title: Top Jets at the LHC

abstract:
  We study the reconstruction of high p_T hadronically-decaying top quarks at
the LHC. The main challenge in identifying energetic top quarks is that the
decay products become increasingly collimated. This reduces the efficacy of
conventional methods that exploit the topology of the top decay chain. We focus
on the cases where the decay products of the top quark are reconstructed as a
single jet, a "top-jet". The most basic "top-tag" method based on jet mass
measurement is considered in detail. To analyze the top-tagging method,
theoretical and experimental aspects of the QCD jet background are examined.
Based on QCD factorization, we derive a simple analytic approximation for the
shape of the QCD jet mass spectrum. We observe a good agreement with the Monte
Carlo simulation. We consider high-p_T t\bar{t} production in the Standard
Model as an example, and show that our theoretical QCD jet mass distributions
can efficiently characterize the background via sideband analyses. We show that
with 25 fb^{-1} of data, our approach allows us to resolve top-jets with p_T
$\ge$ 1 TeV from the QCD background, and about 1.5 TeV top-jets with 100
fb^{-1}, without relying on b-tagging. To further improve the significance we
consider jet shapes (analyzed in 0807.0234 [hep-ph]), which resolve the
substructure of energy flow inside cone jets. A method of measuring top quark
polarization by using the b-quark p_T is also presented. The main advantages of
our approach are: (i) the mass distributions are driven by first principle
calculations, instead of relying solely on Monte Carlo simulation; (ii) for
high p_T jets (p_T $\ge$1 TeV), IR-safe jet shape variables are robust against
detector resolution effects. Our analysis is applicable to other boosted
massive particles such as the electroweak gauge bosons and the Higgs.


title:
Unsolvability of the isomorphism problem for [free abelian]-by-free
  groups

abstract: The isomorphism problem for [free abelian]-by-free groups is unsolvable.


title:
Coherent electronic transport through graphene constrictions:
  sub-wavelength regime and optical analogies

abstract:
  Graphene two-dimensional nature combined with today lithography allows to
achieve nanoelectronics devices smaller than the Dirac electrons wavelength.
Here we show that in these graphene subwavelength nanodevices the electronic
quantum transport properties present deep analogies with classical phenomena of
subwavelength optics. By introducing the concept of electronic diffraction
barrier to represent the effect of constrictions, we can easily describe the
rich transport physics in a wealth of nanodevices: from Bethe and Kirchhoff
diffraction in graphene slits, to Fabry-Perot interference oscillations in
nanoribbons. The same concept applies to graphene quantum dots and gives new
insigth into recent experiments on these systems.


title: AdS Vacua, Attractor Mechanism and Generalized Geometries

abstract:
  We consider flux vacua attractor equations in type IIA string theory
compactified on generalized geometries with orientifold projections. The
four-dimensional N=1 superpotential in this compactification can be written as
the sum of the Ramond-Ramond superpotential and a term described by
(non)geometric flux charges. We exhibit a simple model in which supersymmetric
AdS and Minkowski solutions are classified by means of discriminants of the two
superpotentials. We further study various configurations without Ramond-Ramond
flux charges. In this case we find supersymmetric AdS vacua both in the case of
compactifications on generalized geometries with SU(3) x SU(3) structures and
on manifolds with an SU(3)-structure without nongeometric flux charges. In the
latter case, we have to introduce correction terms into the prepotential in
order to realize consistent vacua.


title:
The efficiency of convective tidal viscosity in close solar-type
  binaries

abstract:
  The value of the effective convective viscosity, in the framework of the
mixing length theory (MLT), is 2 orders of magnitude too small compared to that
required by the observational data. Moreover, the reduction of the effective
viscosity due to the fast time-variation of the tidal shear in short period
binaries, increases the discrepancy to about three orders of magnitude. In this
work, we examine the possibility that the apparent inefficiency of turbulent
convection is merely a shortcoming of MLT approach. We employ a model for
stellar turbulent convection (Canuto, Goldman & Mazzitelli 1996) and use an
analytic approximation to the turbulent spectrum. The resulting efficiency is
substantially increased; the discrepancy is a factor of 30 down from a factor
of 1000. This encouraging result motivates an investigation of the full
non-analytic solutions of the turbulent spectrum.


title:
A new measurement of Beam Asymmetry in Pion Photoproduction from the
  Neutron using CLAS

abstract:
  We present a preliminary analysis of the photon beam asymmetry observable
(Sigma) from the photoproduction reaction channel gamma+ n -> p + pi-. This new
data was obtained using the near-4pi CEBAF Large Acceptance Spectrometer (CLAS)
at Jefferson Laboratory, USA, employing a linearly polarised photon beam with
an energy range 1.1 - 2.3 GeV. The measurement will provide new data to address
the poorly established neutron excitation spectrum and will greatly expand the
sparse world data-set both in energy and angle.


title: The Covariant Measure of SLE on the Boundary

abstract:
  We construct a natural measure mu supported on the intersection of a chordal
SLE(kappa) curve gamma with the real line R, in the range 4 < kappa < 8. The
measure is a function of the SLE path in question. Assuming that boundary
measures transform in a ``d-dimensional'' way (where d is the Hausdorff
dimension of gamma intersected with R), we show that the measure we construct
is (up to multiplicative constant) the unique measure-valued function of the
SLE path that satisfies the Domain Markov property.


title: GMRT study of X-shaped radio sources

abstract:
  Context. The nature of X-shaped sources is a matter of considerable debate in
the literature: it has even been proposed that they provide evidence for
black-hole-mergers/spin-reorientation, and therefore constrain the rate of
strong gravitational wave events. Aim. To explore the nature of these X-shaped
radio galaxies. Method. We conduct a systematic study of a large sample of
known and newly discovered X-shaped sources along with a comparison sample. We
used the Giant Metrewave Radio Telescope with resolution of
$\sim6^{\prime\prime}$ to $\sim15^{\prime\prime}$ at 610 MHz and 240 MHz in the
dual-frequency mode. Preliminary Result. Based on our careful analysis and
estimation of the possible systematic errors, the known X-shaped sources divide
into the following three categories: (i) the wings have flatter spectral
indices than the active lobes, (ii) the wings and the active lobes have
comparable spectral indices, and (iii) the wings have steeper spectral indices
than the active lobes. In addition, based on our preliminary analysis, one
sample source from our comparison sample shows a spectral index result
belonging to category (i). Future. Milliarcsecond scale imaging will be
conducted on some of these X-shaped sources to investigate if they are examples
of binary AGN systems and thereby understand the nature of these sources.


title: Testing a Bell inequality in multi-pair scenarios

abstract:
  To date, most efforts to demonstrate quantum nonlocality have concentrated on
systems of two (or very few) particles. It is however difficult in many
experiments to address individual particles, making it hard to highlight the
presence of nonlocality. We show how a natural setup with no access to
individual particles allows one to violate the CHSH inequality with many pairs,
including in our analysis effects of noise and losses. We discuss the case of
distinguishable and indistinguishable particles. Finally, a comparison of these
two situations provides new insight into the complex relation between
entanglement and nonlocality.


title:
Array configuration studies for the SKA -- Implementation of figures of
  merit based on SDR

abstract:
  The Square Kilometre Array is going to become operational at the time when
several new large optical, X-ray and Gamma-ray telescopes are expected to be
working. The main drive for building the SKA is a significant improvement of
sensitivity that would widen the general scope of the centimetre-wavelength
radio science. To this end, a thorough design studies should be made, in order
to ensure that the SKA becomes a competitive counterpart of the facilities at
other wavebands.
  To quantify imaging performance of the SKA configurations, we are
implementing figures of merit based on spatial dynamic range (SDR). This work
is focused on extensive numerical tests of the analytical, SDR--based figures
of merit derived in the SKA Memo 38 (A. Lobanov). Here, we present our
preliminary results.


title: A Principal Component Analysis for Trees

abstract:
  The active field of Functional Data Analysis (about understanding the
variation in a set of curves) has been recently extended to Object Oriented
Data Analysis, which considers populations of more general objects. A
particularly challenging extension of this set of ideas is to populations of
tree-structured objects. We develop an analog of Principal Component Analysis
for trees, based on the notion of tree-lines, and propose numerically fast
(linear time) algorithms to solve the resulting optimization problems. The
solutions we obtain are used in the analysis of a data set of 73 individuals,
where each data object is a tree of blood vessels in one person's brain.

categories: math.ST math.OC q-bio.QM stat.CO stat.TH


title:
"Normal" FRII Radio Galaxies as a Probe of the Nature of X-Shaped Radio
  Sources

abstract:
  We present a multiwavelength radio study of a sample of nearby Fanaroff-Riley
class II (FRII) radio galaxies, matched with the sample of known X-shaped radio
sources in size, morphological properties and redshift, using new Giant
Metrewave Radio Telescope (GMRT) data and archival data from the Very Large
Array (VLA). Our principal aim in this paper is to provide a control sample for
earlier studies of samples of `X-shaped' radio sources, which have similar
luminosities and small-scale radio structures to our targets but exhibit
large-scale extensions to their lobes that more typical FRII sources lack;
earlier spectral work with the GMRT has suggested that these `wings' sometimes
have flat spectral indices at low frequencies, in contrast to expectations from
models in which the wings are formed hydrodynamically or by jet reorientation.
In our new observations we find that almost all of our target FRII radio
galaxies show standard spectral steepening as a function of distance from the
hotspot at the low frequencies (610 MHz and 240 MHz) provided by the GMRT data,
even when transverse extensions to the lobes are present. However, one source,
3C321, has a low-surface-brightness extension to one lobe that shows a flatter
spectral index than the high-surface-brightness hotspots/lobes, as found in
X-shaped sources.


title: Fluctuations and reweighting of the quark determinant on large lattices

abstract:
  We propose to stabilise HMC simulations of lattice QCD with very light Wilson
quarks by splitting the quark determinant into two factors and by treating the
factor that includes the contribution of the low modes of the Dirac operator as
a reweighting factor. In general, determinant reweighting becomes inefficient
on large lattices, because the statistical fluctuations of quark determinants
increase exponentially with the lattice volume. Random matrix theory and some
numerical studies now suggest that the low-mode contribution to the determinant
behaves differently, which allows factorisations to be devised that preserve
the efficiency of the simulation on large lattices.


title: New inclusion and coincidence theorems for summing multilinear mappings

abstract:
  In this paper we obtain new inclusion and coincidence theorems for absolutely
or multiple summing multilinear mappings. In particular, we derive optimal
coincidence theorems of Bohnenblust-Hille type for multilinear forms on
K-convex Banach spaces of cotype 2.


title: The effect of thresholding on temporal avalanche statistics

abstract:
  We discuss intermittent time series consisting of discrete bursts or
avalanches separated by waiting or silent times. The short time correlations
can be understood to follow from the properties of individual avalanches, while
longer time correlations often present in such signals reflect correlations
between triggerings of different avalanches. As one possible source of the
latter kind of correlations in experimental time series, we consider the effect
of a finite detection threshold, due to e.g. experimental noise that needs to
be removed. To this end, we study a simple toy model of an avalanche, a random
walk returning to the origin or a Brownian bridge, in the presence and absence
of superimposed delta-correlated noise. We discuss the properties after
thresholding of artificial timeseries obtained by mixing toy avalanches and
waiting times from a Poisson process. Most of the resulting scalings for
individual avalanches and the composite timeseries can be understood via random
walk theory, except for the waiting time distributions when strong additional
noise is added. Then, to compare with a more complicated case we study the
Manna sandpile model of self-organized criticality, where some further
complications appear.


title:
Two-colour photometry of the binary planetary nebula nuclei UU Sagitte
  and V477 Lyrae: oversized secondaries in post-common-envelope binaries

abstract:
  We present new V and R-passband CCD photometry of UU Sge and V477 Lyr, the
eclipsing binary nuclei of the planetary nebulae Abell 63 and Abell 46,
respectively. We have performed a simultaneous analysis of VR light-curves and
estimated the effective temperatures for the primary and secondary stars to be
78 000 $\pm$ 3000 and 6136 $\pm$ 240 K for UU Sge, 49 500 $\pm$ 4500 and 3874
$\pm$ 350 K for V477 Lyr. We have also reanalysed the previously measured
radial velocities and combined the results with those obtained from the
analysis of the light curves to derive absolute parameters of the components.
The secondary stars have larger radii than expected from their main--sequence
counterparts at the same masses. We have determined the post--common envelope
ages and the thermal time scales of the systems and examined the possible
reasons of expanded radius of the secondary components, together with some
selected post-common envelope binaries. We conclude that the secondary
components of the nuclei of the planetary nebulae are still out of thermal
equilibrium along with two post-common envelope systems: HS 1136+6646 and RE
1016-053. For other systems, magnetic activity has been suggested as the more
plausible reason for their expanded radii. We have also estimated the
common--envelope efficiency parameters of UU Sge and V477 Lyr.


title:
Interfacial separation between elastic solids with randomly rough
  surfaces: comparison of experiment with theory

abstract:
  We study the average separation between an elastic solid and a hard solid
with a nominal flat but randomly rough surface, as a function of the squeezing
pressure. We present experimental results for a silicon rubber (PDMS) block
with a flat surface squeezed against an asphalt road surface. The theory shows
that an effective repulse pressure act between the surfaces of the form p
proportional to exp(-u/u0), where u is the average separation between the
surfaces and u0 a constant of order the root-mean-square roughness, in good
agreement with the experimental results.


title:
High energy astrophysics with the next generation of radio astronomy
  facilities

abstract:
  High energy astrophysics has made good use of combined high energy (X-ray,
gamma-ray) and radio observations to uncover connections between outbursts,
accretion, particle acceleration and kinetic feedback to the local ambient
medium. In the field of microquasars the connections have been particularly
important. However, radio astronomy has been relying on essentially the same
facilities for the past ~25 years, whereas high-energy astrophysics, in
particular space-based research, has had a series of newer and more powerful
missions. In the next fifteen years this imbalance is set to be redressed, with
a whole familiy of new radio facilities under development en route to the
Square Kilometre Array (SKA) in the 2020s. In this brief review I will
summarize these future prospects for radio astronomy, and focus on possibly the
most exciting of the new facilities to be built in the next decade, the Low
Frequency Array LOFAR, and its uses in high energy astrophysics.


title: On Okuyama's theorems about Alvis-Curtis duality

abstract:
  The purpose of this paper is to report on the unpublished manuscript [O] by
T. Okuyama where are proved some conjectures generalizing to homotopy
categories the theorems of [CaRi] and [LS] holding in derived categories. We
refer to the latter references and [CaEn]~\S 4 for a broader introduction to
the subject.
  The main theme is the one of complexes related with the Coxeter complex and
the action of parabolic subgroups on them, either for finite groups with
BN-pairs or for finite dimensional Hecke algebras. Okuyama's contractions prove
a quite efficient tool in a number of situations (see the proof of Solomon-Tits
theorem in \S~6).
  We often stray away from Okuyama's proofs when it allows simplifications.


title: Double vector quarkonia production in exclusive Higgs boson decays

abstract:
  Partial decay widths and branching fractions are calculated for the exclusive
decays of the Standard Model Higgs boson into a pair of vector quarkonium
states, $ H\to J/\psi J/\psi, H\to \Upsilon \Upsilon, H\to J/\psi \phi, H\to
J/\psi \Upsilon$, with relativistic corrections due to quark motion in mesons
taken into account.


title:
MAXI, LOFAR and Microquasars - All-sky monitoring of X-ray binaries in
  X-rays and radio

abstract:
  In this paper I will discuss future synergies between the Japanese MAXI X-ray
all-sky monitor, to be placed on the International Space Station in 2009, and
the next-generation radio astronomy array LOFAR, currently under construction
in The Netherlands. The wide fields of view and multiple beams of LOFAR will
allow, in combination with MAXI, simultaneous all-sky monitoring of the sky in
both the X-ray and radio bands. Focussing on microquasars, X-ray binary jet
systems, I discuss how the combination of MAXI and LOFAR will help us to
further understand the accretion--outflow coupling in such systems.


title:
Experimental Plan to Verify the YPCP Model: "Yukawa Pico Chemistry and
  Physics" Implications in the CF-Lenr Field

abstract:
  In the CF-LERN field (Cold Fusion and Low Energy Nuclear reactions) many
experimental results are available: unexplained energy production, presence of
unusual patterns of classical fusion reaction products, isotopic composition
variations, sporadic emission of nuclear radiations. These effects are not
always observed, for similar experimental conditions. Should a fundamental
reason exist for these effects to occur, funding would be justified, to make
them repeatable and more intense (this step being likely to be a trial and
error process, might require a substantial amount of money). In this article, a
possible fundamental explanation of the phenomenon is described, together with
the experimental plan to assess it.