title: On regular configurations and disjoint cycles in shift graphs

abstract:
  Configurations are necklaces with prescribed numbers of red and black beads.
Among all possible configurations, the regular one plays an important role in
many applications. In this paper, several aspects of regular configurations are
discussed, including construction, uniqueness, symmetry group and the link with
balanced words.
  Another model of configurations is the polygons formed by a given number of
sides of two different lengths. In this context, regular configurations are
used to obtain a lower bound for the cycles packing number of shift graphs, a
subclass of the directed circulant graphs.


title:
Reduced Weyl asymptotics for pseudodifferential operators on bounded
  domains II. The compact group case

abstract:
  Let $G\subset \O(n)$ be a compact group of isometries acting on
$n$-dimensional Euclidean space $\R^n$, and ${\bf{X}}$ a bounded domain in
$\R^n$ which is transformed into itself under the action of $G$. Consider a
symmetric, classical pseudodifferential operator $A_0$ in $\L^2(\R^n)$ that
commutes with the regular representation of $G$, and assume that it is elliptic
on $\bf{X}$. We show that the spectrum of the Friedrichs extension $A$ of the
operator $\mathrm{res} \circ A_0 \circ \mathrm{ext}: \CT({\bf{X}}) \to
\L^2({\bf{X}})$ is discrete, and using the method of the stationary phase, we
derive asymptotics for the number $N_\chi(\lambda)$ of eigenvalues of $A$ equal
or less than $\lambda$ and with eigenfunctions in the $\chi$-isotypic component
of $\L^2({\bf{X}})$ as $\lambda \to \infty$, giving also an estimate for the
remainder term for singular group actions. Since the considered critical set is
a singular variety, we recur to partial desingularization in order to apply the
stationary phase theorem.


title:
Difficulty in the Fermi-Liquid-Based Theory for the In-Plane Magnetic
  Anisotropy in Untwinned High-T_c Superconductor

abstract:
  Recently, Eremin and Manske [1] presented a oneband Fermi-liquid theory for
the in-plane magnetic anisotropy in untwinned high-Tc superconductor
YBa2Cu3O6:85 (YBCO). They claimed that they found good agreement with inelastic
neutron scattering (INS) spectra. In this Comment, we point out that their
conclusion on this important problem may be questionable due to an error in
logic about the orthorhombicity delta_0 characterizing the lattice structure of
YBCO. In Ref. [1], a single band at delta_0>0 is proved to be in accordance
with the angle resolved photoemission spectroscopy (ARPES) on untwinned YBCO.
But in their Erratum in PRL[3], they admit that delta_0= -0.03 was used to fit
the INS data. Hence publications [1,3] contain errors that we believe
invalidate their approach.


title:
Investigation of the Faraday Rotation Measure and Magnetic Field
  Structures of Several AGN Jets on Sub-Parsec to Parsec Scales

abstract:
  Preliminary VLBA polarisation results on 6 ``blazars'' from 6.5-cm to 7-mm
are presented here. Observing at several different wavelengths, separated by
short and long intervals, enabled reliable information about the magnetic (B)
field structure to be obtained and for the effect of Faraday Rotation to be
determined and corrected. For all sources the magnitude of the core Rotation
Measure (RM) derived from the shorter wavelength data was greater than that
derived from the longer wavelength data, consistent with a higher electron
density and/or B-field strength closer to the central engine. A transverse RM
gradient was detected in the jet of 0954+658, providing evidence for the
presence of a helical B-field surrounding the jet. The RM in the core region of
2200+420 (BL Lac) displays sign changes in different wavelength intervals (on
different spatial scales); we suggest an explanation for this in terms of
modest bends in a helical B-field surrounding the jet.


title:
Existence and mutiplicity of solutions to elliptic equations of fourth
  order on compact manifolds

abstract:
  This paper deals with a fourth order elliptic equation on compact Riemannian
manifolds.We establish the existence of solutions to the equation with critical
Sobolev growth which is the subject of the first theorem. In the second one, we
prove the multiplicity of solutions in the subcritical case.


title: Tests \`a la Hurewicz dans le plan

abstract:
  We give, for some Borel sets of a product of two Polish spaces, including the
Borel sets with countable sections, a Hurewicz-like characterization of those
which cannot become a transfinite difference of open sets by changing the two
Polish topologies.


title: Uniformisations partielles et crit\`eres \`a la Hurewicz dans le plan

abstract:
  We give characterizations of the Borel sets potentially in some Wadge class,
among the Borel sets with countable vertical sections of a product of two
Polish spaces. To do this, we use some partial uniformization results.


title: Classes de Wadge potentielles des bor\'eliens \`a coupes d\'enombrables

abstract:
  We give, for each non self-dual Wadge class C contained in the class of the
Gdelta sets, a characterization of Borel sets which are not potentially in C,
among Borel sets with countable vertical sections; to do this, we use results
of partial uniformization.


title:
Classes de Wadge potentielles et th\'eor\`emes d'uniformisation
  partielle

abstract:
  We want to give a construction as simple as possible of a Borel subset of a
product of two Polish spaces. This introduces the notion of potential Wadge
class. Among other things, we study the non-potentially closed sets, by proving
Hurewicz-like results. This leads to partial uniformization theorems, on big
sets, in the sense of cardinality or Baire category.


title: Complexit\'e des bor\'eliens \`a coupes d\'enombrables

abstract:
  We give, for each level of complexity L, a Hurewicz-like characterization of
the Borel subsets with countable sections of a product of two Polish spaces
that cannot become in L by changing the two Polish topologies.


title: Neutralino Annihilations and the Gas Temperature in the Dark Ages

abstract:
  Assuming the dark matter is made entirely from neutralinos, we re-visit the
role of their annihilation on the temperature of diffuse gas in the high
redshift universe. We consider neutralinos of particle mass 36 GeV and 100 GeV,
respectively. The former is able to produce ~7 electron/positron particles per
annihilation through the fremionic channel, and the latter ~53 particles
assuming a purely bosonic channel. High energy electron/positron particles
up-scatter the Cosmic Microwave Background (CMB) photons into higher energies
via the inverse-Compton scattering. The process produces a power-law
electron/positron energy spectrum of index -1 in the energy range of interest,
independent of the initial energy distribution. The corresponding energy
spectrum of the up-scattered photons is a power-law of index -1/2, if
absorption by the gas is not included. The scattered photons photo-heat the gas
by releasing electrons which deposit a fraction (14%)of their energy as heat
into the ambient medium. For uniformly distributed neutralinos the heating is
insignificant. The effect is greatly enhanced by the clumping of neutralinos
into dense haloes. We use a time-dependent clumping model which takes into
account the damping of density fluctuations on mass scales smaller than
~10^{-6}M_sol. With this clumping model, the heating mechanism boosts the gas
temperature above that of the CMB after a redshift of z 30. By z\approx 10 the
gas temperature is nearly 100 times its temperature when no heating is invoked.
Similar increase is obtained for the two neutralino masses considered.


title:
A Simple Model for Cavity Enhanced Slow Lights in Vertical Cavity
  Surface Emission Lasers

abstract:
  We develop a simple model for the slow lights in Vertical Cavity Surface
Emission Lasers (VCSELs), with the combination of cavity and population
pulsation effects. The dependences of probe signal power, injection bias
current and wavelength detuning for the group delays are demonstrated
numerically and experimentally. Up to 65 ps group delays and up to 10 GHz
modulation frequency can be achieved in the room temperature at the wavelength
of 1.3 $\mu$m. The most significant feature of our VCSEL device is that the
length of active region is only several $\mu$m long. Based on the experimental
parameters of quantum dot VCSEL structures, we show that the resonance effect
of laser cavity plays a significant role to enhance the group delays.


title: The B and Be Star Population of NGC 3766

abstract:
  We present multiple epochs of H-alpha spectroscopy for 47 members of the open
cluster NGC 3766 to investigate the long term variability of its Be stars.
Sixteen of the stars in this sample are Be stars, including one new discovery.
Of these, we observe an unprecedented 11 Be stars that undergo disk appearances
and/or near disappearances in our H-alpha spectra, making this the most
variable population of Be stars known to date. NGC 3766 is therefore an
excellent location to study the formation mechanism of Be star disks. From blue
optical spectra of 38 cluster members and existing Stromgren photometry of the
cluster, we also measure rotational velocities, effective temperatures, and
polar surface gravities to investigate the physical and evolutionary factors
that may contribute to the Be phenomenon. Our analysis also provides
improvements to the reddening and distance of NGC 3766, and we find E(B-V) =
0.22 +/- 0.03 and (V-M_V)_0 = 11.6 +/- 0.2, respectively. The Be stars are not
associated with a particular stage of main-sequence evolution, but they are a
population of rapidly rotating stars with a velocity distribution generally
consistent with rotation at 70-80% of the critical velocity, although
systematic effects probably underestimate the true rotational velocities so
that the rotation is much closer to critical. Our measurements of the changing
disk sizes are consistent with the idea that transitory, nonradial pulsations
contribute to the formation of these highly variable disks.


title: K-matrix and Dalitz plot analysis from FOCUS

abstract:
  Dalitz analysis is a powerful tool for physics studies within and beyond the
Standard Model. In the last decade it has helped to investigate the Heavy
Flavor hadronic decay dynamics and is now being applied to extract angles of
the CKM Unitarity triangle. To perform such sophisticate analyses we need to
model the strong interaction effects. The FOCUS experiment has performed pilot
studies in the charm sector through the K-matrix formalism. What has been
learnt from charm will be beneficial for future accurate beauty measurements.
Experience and results from FOCUS are presented and discussed.


title: Getting a kick out of the stellar disk(s) in the galactic center

abstract:
  Recent observations of the Galactic center revealed a nuclear disk of young
OB stars, in addition to many similar outlying stars with higher eccentricities
and/or high inclinations relative to the disk (some of them possibly belonging
to a second disk). Binaries in such nuclear disks, if they exist in
non-negligible fractions, could have a major role in the evolution of the disks
through binary heating of this stellar system. We suggest that interactions
with/in binaries may explain some (or all) of the observed outlying young stars
in the Galactic center. Such stars could have been formed in a disk, and later
on kicked out from it through binary related interactions, similar to ejection
of high velocity runaway OB stars in young clusters throughout the galaxy.


title: High density effective theory on the lattice

abstract:
  Long-range interactions in finite density QCD necessitate a non-perturbative
approach in order to reliably map out the key features and spectrum of the QCD
phase diagram. However, the complex nature of the fermion determinant in this
sector prohibits the use of established Monte Carlo techniques that utilize
importance sampling. Whilst significant progress has been made in the low
density, high temperature region, this remains a considerable challenge at mid
to high density. At large chemical potential, QCD can be approximated using
high density effective theory which is free from the sign problem at leading
order. We investigate the implementation of this theory on the lattice in
conjunction with existing re-weighting techniques.


title: Dense gas in luminous infrared galaxies

abstract:
  Molecules that trace the high-density regions of the interstellar medium have
been observed in (ultra-)luminous (far-)infrared galaxies, in order to initiate
multiple-molecule multiple-transition studies to evaluate the physical and
chemical environment of the nuclear medium and its response to the ongoing
nuclear activity.
  The HCN(1-0), HNC(1-0), HCO+(1-0), CN(1-0) and CN(2-1), CO(2-1), and CS(3-2)
transitions were observed in sources covering three decades of infrared
luminosity including sources with known OH megamaser activity. The data for the
molecules that trace the high-density regions have been augmented with data
available in the literature.
  The integrated emissions of high-density tracer molecules show a strong
relation to the far-infrared luminosity. Ratios of integrated line luminosities
have been used for a first order diagnosis of the integrated molecular
environment of the evolving nuclear starbursts. Diagnostic diagrams display
significant differentiation among the sources that relate to initial conditions
and the radiative excitation environment. Initial differentiation has been
introduced between the FUV radiation field in photon-dominated-regions and the
X-ray field in X-ray-dominated-regions. The galaxies displaying OH megamaser
activity have line ratios typical of photon-dominated regions.


title: LDPC codes in the McEliece cryptosystem: attacks and countermeasures

abstract:
  The McEliece cryptosystem is a public-key cryptosystem based on coding theory
that has successfully resisted cryptanalysis for thirty years. The original
version, based on Goppa codes, is able to guarantee a high level of security,
and is faster than competing solutions, like RSA. Despite this, it has been
rarely considered in practical applications, due to two major drawbacks: i)
large size of the public key and ii) low transmission rate. Low-Density
Parity-Check (LDPC) codes are state-of-art forward error correcting codes that
permit to approach the Shannon limit while ensuring limited complexity.
Quasi-Cyclic (QC) LDPC codes are a particular class of LDPC codes, able to join
low complexity encoding of QC codes with high-performing and low-complexity
decoding of LDPC codes. In a previous work it has been proposed to adopt a
particular family of QC-LDPC codes in the McEliece cryptosystem to reduce the
key size and increase the transmission rate. Recently, however, new attacks
have been found that are able to exploit a flaw in the transformation from the
private key to the public one. Such attacks can be effectively countered by
changing the form of some constituent matrices, without altering the system
parameters. This work gives an overview of the QC-LDPC codes-based McEliece
cryptosystem and its cryptanalysis. Two recent versions are considered, and
their ability to counter all the currently known attacks is discussed. A third
version able to reach a higher security level is also proposed. Finally, it is
shown that the new QC-LDPC codes-based cryptosystem scales favorably with the
key length.


title: Generalized Taylor's Theorem

abstract:
  The Euclidean algorithm makes possible a simple but powerful generalization
of Taylor's theorem. Instead of expanding a function in a series around a
single point, one spreads out the spectrum to include any number of points with
given multiplicities. Taken together with a simple expression for the
remainder, this theorem becomes a powerful tool for approximation and
interpolation in numerical analysis. We also have a corresponding theorem for
rational approximation.


title: Two Digit Theorems

abstract:
  We prove that if p is a prime with a primitive root 2 then S_p(2^p)=p and
give a sufficient condition for an equality of kind S_p(2^p)=+or-p.


title: Applications of integral transforms in fractional diffusion processes

abstract:
  The fundamental solution (Green function) for the Cauchy problem of the
space-time fractional diffusion equation is investigated with respect to its
scaling and similarity properties, starting from its Fourier-Laplace
representation. Then, by using the Mellin transform, a general representation
of the Green function in terms of Mellin-Barnes integrals in the complex plane
is derived. This allows us to obtain a suitable computational form of the Green
function in the space-time domain and to analyse its probability
interpretation.


title:
Anisotropic Lavine's formula and symmetrised time delay in scattering
  theory

abstract:
  We consider, in quantum scattering theory, symmetrised time delay defined in
terms of sojourn times in arbitrary spatial regions symmetric with respect to
the origin. For potentials decaying more rapidly than $|x|^{-4}$ at infinity,
we show the existence of symmetrised time delay, and prove that it satisfies an
anisotropic version of Lavine's formula. The importance of an anisotropic
dilations-type operator is revealed in our study.


title: Polymer Translocation out of Planar Confinements

abstract:
  Polymer translocation in three dimensions out of planar confinements is
studied in this paper. Three membranes are located at $z=-h$, $z=0$ and
$z=h_1$. These membranes are impenetrable, except for the middle one at $z=0$,
which has a narrow pore. A polymer with length $N$ is initially sandwiched
between the membranes placed at $z=-h$ and $z=0$ and translocates through this
pore. We consider strong confinement (small $h$), where the polymer is
essentially reduced to a two-dimensional polymer, with a radius of gyration
scaling as $R^{\tinytext{(2D)}}_g \sim N^{\nu_{\tinytext{2D}}}$; here,
$\nu_{\tinytext{2D}}=0.75$ is the Flory exponent in two dimensions. The polymer
performs Rouse dynamics. Based on theoretical analysis and high-precision
simulation data, we show that in the unbiased case $h=h_1$, the dwell-time
$\tau_d$ scales as $N^{2+\nu_{\tinytext{2D}}}$, in perfect agreement with our
previously published theoretical framework. For $h_1=\infty$, the situation is
equivalent to field-driven translocation in two dimensions. We show that in
this case $\tau_d$ scales as $N^{2\nu_{\tinytext{2D}}}$, in agreement with
several existing numerical results in the literature. This result violates the
earlier reported lower bound $N^{1+\nu}$ for $\tau_d$ for field-driven
translocation. We argue, based on energy conservation, that the actual lower
bound for $\tau_d$ is $N^{2\nu}$ and not $N^{1+\nu}$. Polymer translocation in
such theoretically motivated geometries thus resolves some of the most
fundamental issues that are the subjects of much heated debate in recent times.


title: D1-brane in beta-Deformed Background

abstract:
  We study various configurations of rotating and wound D1-brane in AdS_5\times
S^5 background and in its beta deformed version. We find giant magnon and spike
solutions on the world-volume of D1-brane in AdS_5\times S^5 background. We
also analyse the equations of motion of D1-brane in beta-deformed background.
We show that in the limit of large electric flux on world-volume of D1-brane
they reduce to the equations that describe collection of large number of
fundamental strings. We also construct rotating and wound D1-brane solution
that has two equal spins on S^5_\gamma.


title:
Multi-Channel Selective Femtosecond Coherent Control Based on Symmetry
  Properties

abstract:
  We present and implement a new scheme for extended multi-channel selective
femtosecond coherent control based on symmetry properties of the excitation
channels. Here, an atomic non-resonant two-photon absorption channel is
coherently incorporated in a resonance-mediated (2+1) three-photon absorption
channel. By proper pulse shaping, utilizing the invariance of the two-photon
absorption to specific phase transformations of the pulse, the three-photon
absorption is tuned independently over order-of-magnitude yield range for any
possible two-photon absorption yield. Noticeable is a set of two-photon dark
pulses inducing widely-tunable three-photon absorption.


title: Phase heterogeneities of lipidic aggregates

abstract:
  We propose a model for explanation the "domain-wall" type configuration
states in binary lipid mixtures of cationic and neutral lipids, associated with
observed relaxation effects in their aggregates. We apply the analogy with
formation of Kibble-\.Zurek topological defects, which we suppose connected
with structural dynamics of the lipid phases. In frames of the proposed model,
the density of kink-type defects and the energy of the configurations are
calculated.


title: Charm Mixing - Theory

abstract:
  We discuss Standard Model (SM) and New Physics (NP) descriptions of D0
mixing. The SM part of the discussion addresses both quark level and hadron
level contributions. The NP part describes our recent works on the rate
difference Delta Gamma_D and the mass difference Delta M_D. In particular, we
describe how the recent experimental determination of Delta M_D is found to
place tightened restrictions on parameter spaces for 17 of 21 NP models
considered in a recent paper by Hewett, Pakvasa, Petrov and myself.


title: On minimal non-potentially closed subsets of the plane

abstract:
  We study the Borel subsets of the plane that can be made closed by refining
the Polish topology on the real line. These sets are called potentially closed.
We first compare Borel subsets of the plane using products of continuous
functions. We show the existence of a perfect antichain made of minimal sets
among non-potentially closed sets. We apply this result to graphs, quasi-orders
and partial orders. We also give a non-potentially closed set minimum for
another notion of comparison. Finally, we show that we cannot have injectivity
in the Kechris-Solecki-Todorcevic dichotomy about analytic graphs.


title: Omega-powers and descriptive set theory

abstract:
  We study the sets of the infinite sentences constructible with a dictionary
over a finite alphabet, from the viewpoint of descriptive set theory. Among
other things, this gives some true co-analytic sets. The case where the
dictionary is finite is studied and gives a natural example of a set at the
level omega of the Wadge hierarchy.


title: Hurewicz-like tests for Borel subsets of the plane

abstract:
  Let xi be a non-null countable ordinal. We study the Borel subsets of the
plane that can be made $\bormxi$ by refining the Polish topology on the real
line. These sets are called potentially $\bormxi$. We give a Hurewicz-like test
to recognize potentially $\bormxi$ sets.


title: How can we recover Baire class one functions?

abstract:
  Let X and Y be separable metrizable spaces, and f:X-->Y be a function. We
want to recover f from its values on a small set via a simple algorithm. We
show that this is possible if f is Baire class one, and in fact we get a
characterization. This leads us to the study of sets of Baire class one
functions and to a characterization of the separability of the dual space of an
arbitrary Banach space.


title: Sharp estimates for maximal operators associated to the wave equation

abstract:
  We give almost sharp conditions under which the maximal operator associated
with the wave equation with initial data in Sobolev space H^s(R^n) is bounded
from H^s(R^n) to L^q(R^n).


title: PCF and Abelian Groups

abstract:
  We deal with some pcf investigations mostly motivated by abelian group theory
problems and deal their applications to test problems (we expect reasonably
wide applications). We prove almost always the existence of aleph_omega-free
abelian groups with trivial dual, i.e. no non-trivial homomorphisms to the
integers. This relies on investigation of pcf; more specifically, for this we
prove that "almost always" there are F subseteq lambda^kappa which are quite
free and has black boxes. The "almost always" means that there are strong
restrictions on cardinal arithmetic if the universe fails this, the
restrictions are "everywhere". Also we replace Abelian groups by R-modules, so
in some sense our advantage over earlier results becomes clearer.


title:
High-accuracy comparison of numerical relativity simulations with
  post-Newtonian expansions

abstract:
  Numerical simulations of 15 orbits of an equal-mass binary black hole system
are presented. Gravitational waveforms from these simulations, covering more
than 30 cycles and ending about 1.5 cycles before merger, are compared with
those from quasi-circular zero-spin post-Newtonian (PN) formulae. The
cumulative phase uncertainty of these comparisons is about 0.05 radians,
dominated by effects arising from the small residual spins of the black holes
and the small residual orbital eccentricity in the simulations. Matching
numerical results to PN waveforms early in the run yields excellent agreement
(within 0.05 radians) over the first $\sim 15$ cycles, thus validating the
numerical simulation and establishing a regime where PN theory is accurate. In
the last 15 cycles to merger, however, {\em generic} time-domain Taylor
approximants build up phase differences of several radians. But, apparently by
coincidence, one specific post-Newtonian approximant, TaylorT4 at 3.5PN order,
agrees much better with the numerical simulations, with accumulated phase
differences of less than 0.05 radians over the 30-cycle waveform.
Gravitational-wave amplitude comparisons are also done between numerical
simulations and post-Newtonian, and the agreement depends on the post-Newtonian
order of the amplitude expansion: the amplitude difference is about 6--7% for
zeroth order and becomes smaller for increasing order. A newly derived 3.0PN
amplitude correction improves agreement significantly ($<1%$ amplitude
difference throughout most of the run, increasing to 4% near merger) over the
previously known 2.5PN amplitude terms.


title: Implementation of non-linear gauge-fixing in FeynArts package

abstract:
  Feynman rules for the Standard Model including non-linear gauges are derived
and implemented in the FeynArts package. The calculations using FeynArts with
the new rules show that tree-level amplitudes are gauge invariant and that
renormalization is not spoiled for one-loop calculations. The FeynArts model
files are available at http://www.fi.lt/~garfield/SM/


title:
Affinity criterion for the quotient of an algebraic group by a
  one-dimensional subgroup

abstract:
  In this work we show that the homogeneous space of an affine algebraic group
$G$ by a one-dimensional unipotent subgroup $H$ is affine if and only if the
subgroup is not contained in any reductive subgroup of $G$.


title:
Diffusive hidden Markov model characterization of DNA looping dynamics
  in tethered particle experiments

abstract:
  In many biochemical processes, proteins bound to DNA at distant sites are
brought into close proximity by loops in the underlying DNA. For example, the
function of some gene-regulatory proteins depends on such DNA looping
interactions. We present a new technique for characterizing the kinetics of
loop formation in vitro, as observed using the tethered particle method, and
apply it to experimental data on looping induced by lambda repressor. Our
method uses a modified (diffusive) hidden Markov analysis that directly
incorporates the Brownian motion of the observed tethered bead. We compare
looping lifetimes found with our method (which we find are consistent over a
range of sampling frequencies) to those obtained via the traditional
threshold-crossing analysis (which can vary depending on how the raw data are
filtered in the time domain). Our method does not involve any time filtering
and can detect sudden changes in looping behavior. For example, we show how our
method can identify transitions between long-lived, kinetically distinct states
that would otherwise be difficult to discern.


title: On ground fields of arithmetic hyperbolic reflection groups. II

abstract:
  This paper continues arXiv.org:math.AG/0609256 and arXiv:0708.3991
  Using authors's methods of 1980, 1981, some explicit finite sets of number
fields containing all ground fields of arithmetic hyperbolic reflection groups
in dimensions at least 4 are defined, and good explicit bounds of their degrees
(over Q) are obtained. This could be important for further classification.
  Thus, now, an explicit bound of degree of ground fields of arithmetic
hyperbolic reflection groups is unknown in dimension 3 only.


title:
A few remarks about linear operators and disconnected open sets in the
  plane

abstract:
  Some aspects of analysis on disconnected open subsets of the plane with
connected fractal boundary are discussed.


title: Bochner-Kaehler metrics and connections of Ricci type

abstract:
  We apply the results from the article Cahen, Schwachh\"ofer: Special
symplectic connections, to the case of Bochner-Kaehler metrics. We obtain a
(local) classification of these based on the orbit types of the adjoint action
in $su(n,1)$. The relation between Sasaki and Bochner-Kaehler metrics in cone
and transveral metrics constructions is discussed. The connection of the
special symplectic and Weyl connections is outlined. The duality between the
Ricci-type and Bochner-Kaehler metrics is shown.


title: Charm-Production in e^+e^- Annihilation Around 4 GeV

abstract:
  Using the CLEO-c detector at the Cornell Electron Storage Ring, we have
measured inclusive and exclusive cross sections for the production of $D^+$,
$D^0$ and $D_s^+$ mesons in $e^{+}e^{-}$ annihilations at thirteen
center-of-mass energies between 3.97 and 4.26 GeV. Exclusive cross sections are
presented for final states consisting of two charmed mesons ($D\bar{D}$,
$D^{*}\bar{D}$, $D^{*}\bar{D}^{*}$, $D_s^+ D_s^-$, $D_s^{*+} D_s^-$, and
$D_s^{*+} D_s^{*-}$) and for processes in which the charmed meson pair is
accompanied by a pion.


title: Comments on the ERA-2005 numerical theory of Earth rotation

abstract:
  Two papers recently published in Celestial Mechanics (Krasinsky 2006, and
Krasinsky and Vasilyev 2006) have presented a model for Earth-rotation
variations, called ERA-2005, based on numerical integration of a new set of
equations for the rotation of a deformable Earth followed by a fit of the
results of the integration to VLBI data. These papers claimed that this model
was superior to any other existing model. The purpose of this Note is to bring
to light fundamental errors in the derivation of the basic equations of the new
theory, compounded by serious deficiencies in the process of fitting to the
data; they make ERA-2005 unsuitable for consideration as a geophysics-based
model of nutation and precession.


title:
Dominant K-theory and Integrable highest weight representations of
  Kac-Moody groups

abstract:
  We give a topological interpretation of the highest weight representations of
Kac-Moody groups. Given the unitary form G of a Kac-Moody group (over C), we
define a version of equivariant K-theory, K_G on the category of proper G-CW
complexes. We then study Kac-Moody groups of compact type in detail (see
Section 2 for definitions). In particular, we show that the Grothendieck group
of integrable hightest weight representations of a Kac-Moody group G of compact
type, maps isomorphically onto K_G^*(EG), where $EG$ is the classifying space
of proper G-actions. For the affine case, this agrees very well with recent
results of Freed-Hopkins-Teleman. We also explicitly compute K_G^*(EG) for
Kac-Moody groups of extended compact type, which includes the Kac-Moody group
E_{10}.


title: The Dense Gas in the Central Kiloparsec of NGC 6946

abstract:
  We present observations of the HCN and HCO+ J=1-0 transitions in the center
of the nearby spiral galaxy NGC 6946 made with the BIMA and CARMA
interferometers. Using the BIMA SONG CO map, we investigate the change in the
I_HCN/I_CO and I_ HCO/I_CO integrated intensity ratios as a function of radius
in the central kiloparsec of the galaxy, and find that they are strongly
concentrated at the center. We use the 2MASS K_S band image to find the stellar
surface density, and then construct a map of the hydrostatic midplane pressure.
We apply a PDR model to the observed I_HCN/I_HCO+ integrated intensity ratio to
calculate the number density of molecular hydrogen in the dense gas tracer
emitting region, and find that it is roughly constant at 10^5 cm^-3 across our
map. We explore two hypotheses for the distribution of the dense gas. If the
HCN and HCO+ emission comes from self-gravitating density peaks inside of a
less dense gas distribution, there is a linear proportionality between the
internal velocity dispersion of the dense gas and the size of the density peak.
Alternatively, the HCN and HCO+ emission could come from dense gas
homogeneously distributed throughout the center and bound by ambient pressure,
similar to what is observed toward the center of the Milky Way. We find both of
these hypotheses to be plausible. We fit the relationships between I_HCN,
I_HCO+, and I_CO. Correlations between the hydrostatic midplane pressure and
I_HCN and I_HCO+ are demonstrated, and power law fits are provided. We confirm
the validity of a relation found by Blitz & Rosolowsky (2006) between pressure
and the molecular to atomic gas ratio in the high hydrostatic midplane pressure
regime (10^6-10^8 cm^-3 K).


title:
Evaluation experiments on related terms search in Wikipedia: Information
  Content and Adapted HITS (In Russian)

abstract:
  The classification of metrics and algorithms search for related terms via
WordNet, Roget's Thesaurus, and Wikipedia was extended to include adapted HITS
algorithm. Evaluation experiments on Information Content and adapted HITS
algorithm are described. The test collection of Russian word pairs with
human-assigned similarity judgments is proposed.
  -----
  Klassifikacija metrik i algoritmov poiska semanticheski blizkih slov v
tezaurusah WordNet, Rozhe i jenciklopedii Vikipedija rasshirena adaptirovannym
HITS algoritmom. S pomow'ju jeksperimentov v Vikipedii oceneny metrika
Information Content i adaptirovannyj algoritm HITS. Predlozhen resurs dlja
ocenki semanticheskoj blizosti russkih slov.


title: Supersymmetry in 5d Gravity

abstract:
  We study a 5d gravity theory with a warped metric and show that two N = 2
supersymmetric quantum-mechanical systems are hidden in the 4d spectrum. The
supersymmetry can be regarded as a remnant of higher-dimensional general
coordinate invariance and turns out to become a powerful tool to determine the
physical 4d spectrum and the allowed boundary conditions. Possible extensions
of the N = 2 supersymmetry are briefly discussed.


title:
A note on energy currents and decay for the wave equation on a
  Schwarzschild background

abstract:
  In recent work, we have proven uniform decay bounds for solutions of the wave
equation $\Box_g\phi=0$ on a Schwarzschild exterior, in particular, the uniform
pointwise estimate $|\phi|\le Cv_+^{-1}$, which holds throughout the domain of
outer communications, where $v$ is an advanced Eddington-Finkelstein
coordinate, $v_+=\max\{v,1\}$, and $C$ is a constant depending on a Sobolev
norm of initial data. A crucial estimate in the proof required a decomposition
into spherical harmonics. We here give an alternative proof of this estimate
not requiring such a decomposition.


title: The STAR Tracking Upgrade

abstract:
  The STAR experiment at the Relativistic Heavy Ion Collider RHIC studies the
new state of matter produced in relativistic heavy ion collisions and the spin
structure of the nucleon in collisions of polarized protons. In order to
improve the capabilities for heavy flavor measurements and the reconstruction
of charged vector bosons an upgrade of the tracking system both in the central
and the forward region is pursued. The challenging environments of high track
multiplicity in heavy ion collisions and of high luminosity in polarized proton
collisions require the use of new technologies. The proposed inner tracking
system, optimized for heavy flavor identification, is using active pixel
sensors close to the collision point and silicon strip technology further
outward. Charge sign determination for electrons and positrons from the decay
of W bosons will be provide by 6 large-area triple GEM disks currently under
development. A prototype of the active pixel detectors has been tested in the
STAR experiment, and an extensive beam test of triple GEM detectors using GEM
foils produced by Tech-Etch of Plymouth, MA has been done at Fermilab.


title: Eriksson's numbers game and finite Coxeter groups

abstract:
  The numbers game is a one-player game played on a finite simple graph with
certain ``amplitudes'' assigned to its edges and with an initial assignment of
real numbers to its nodes. The moves of the game successively transform the
numbers at the nodes using the amplitudes in a certain way. This game and its
interactions with Coxeter/Weyl group theory and Lie theory have been studied by
many authors. In particular, Eriksson connects certain geometric
representations of Coxeter groups with games on graphs with certain real number
amplitudes. Games played on such graphs are ``E-games.'' Here we investigate
various finiteness aspects of E-game play: We extend Eriksson's work relating
moves of the game to reduced decompositions of elements of a Coxeter group
naturally associated to the game graph. We use Stembridge's theory of fully
commutative Coxeter group elements to classify what we call here the
``adjacency-free'' initial positions for finite E-games. We characterize when
the positive roots for certain geometric representations of finite Coxeter
groups can be obtained from E-game play. Finally, we provide a new Dynkin
diagram classification result of E-game graphs meeting a certain finiteness
requirement.


title: A test of first order scaling in Nf=2 QCD

abstract:
  We complete our analysis of Nf=2 QCD based on the lattice staggered fermion
formulation. Using a series of Monte Carlo simulations at fixed (amq*Ls^yh) one
is able to test the universality class with given critical exponent yh. This
strategy has been used to test the O(4) universality class and it has been
presented at the previous Lattice conferences. No agreement was found with
simulations in the mass range amq=[0.01335,0.15] using lattices with Ls=16 up
to 32 and Lt=4. With the same strategy, we now investigate the possibility of a
first order transition using a new set of Monte Carlo data corresponding to
yh=3 in the same mass and volume range as the one used for O(4). A substantial
agreement is observed both in the specific heat scaling and in the scaling of
the chiral condensate, while the chiral susceptibilities still presents visible
deviation from scaling in the mass range explored.


title: Topological and topological-electronic correlations in amorphous silicon

abstract:
  In this paper, we study several structural models of amorphous silicon, and
discuss structural and electronic features common to all. We note spatial
correlations between short bonds, and similar correlations between long bonds.
Such effects persist under a first principles relaxation of the system and at
finite temperature. Next we explore the nature of the band tail states and find
the states to possess a filamentary structure. We detail correlations between
local geometry and the band tails.


title: Profile of the U 5f magnetization in U/Fe multilayers

abstract:
  Recent calculations, concerning the magnetism of uranium in the U/Fe
multilayer system have described the spatial dependence of the 5f polarization
that might be expected. We have used the x-ray resonant magnetic reflectivity
technique to obtain the profile of the induced uranium magnetic moment for
selected U/Fe multilayer samples. This study extends the use of x-ray magnetic
scattering for induced moment systems to the 5f actinide metals. The spatial
dependence of the U magnetization shows that the predominant fraction of the
polarization is present at the interfacial boundaries, decaying rapidly towards
the center of the uranium layer, in good agreement with predictions.


title:
On a Conjecture about the Number of Solutions to Linear Diophantine
  Equations with a Positive Integer Parameter

abstract:
  Let A(n) be a $k\times s$ matrix and $m(n)$ be a $k$ dimensional vector,
where all entries of A(n) and $m(n)$ are integer-valued polynomials in $n$.
Suppose that $$t(m(n)|A(n))=#\{x\in\mathbb{Z}_{+}^{s}\mid A(n)x=m(n)\}$$ is
finite for each $n\in \mathbb{N}$, where $Z_+$ is the set of nonnegative
integers. This paper conjectures that $t(m(n)|A(n))$ is an integer-valued
quasi-polynomial in $n$ for $n$ sufficiently large and verifies the conjecture
in several cases.


title: Quality assessment for short oligonucleotide microarray data

abstract:
  Quality of microarray gene expression data has emerged as a new research
topic. As in other areas, microarray quality is assessed by comparing suitable
numerical summaries across microarrays, so that outliers and trends can be
visualized, and poor quality arrays or variable quality sets of arrays can be
identified. Since each single array comprises tens or hundreds of thousands of
measurements, the challenge is to find numerical summaries which can be used to
make accurate quality calls. To this end, several new quality measures are
introduced based on probe level and probeset level information, all obtained as
a by-product of the low-level analysis algorithms RMA/fitPLM for Affymetrix
GeneChips. Quality landscapes spatially localize chip or hybridization
problems. Numerical chip quality measures are derived from the distributions of
Normalized Unscaled Standard Errors and of Relative Log Expressions. Quality of
chip batches is assessed by Residual Scale Factors. These quality assessment
measures are demonstrated on a variety of datasets (spike-in experiments, small
lab experiments, multi-site studies). They are compared with Affymetrix's
individual chip quality report.


title:
Wave-particle duality in multi-path interferometers: General concepts
  and three-path interferometers

abstract:
  For two-path interferometers, the which-path predictability $\mathcal{P}$ and
the fringe visibility $\mathcal{V}$ are familiar quantities that are much used
to talk about wave-particle duality in a quantitative way. We discuss several
candidates that suggest themselves as generalizations $P$ of $ mathcal{P}$ for
multi-path interferometers, and treat the case of three paths in considerable
detail. To each choice for the \emph{path knowledge} $P$, the
\emph{interference strength} $V$ -- the corresponding generalization of
$\mathcal{V}$ -- is found by a natural, operational procedure. In experimental
terms it amounts to finding those equal-weight superpositions of the path
amplitudes which maximize $P$ for the emerging intensities. Mathematically
speaking, one needs to identify a certain optimal one among the Fourier
transforms of the state of the interfering quantum object. Wave-particle
duality is manifest, inasmuch as P=1 implies V=0 and V=1 implies P=0, whatever
definition is chosen. The possible values of the pair $(P,V)$ are restricted to
an area with corners at $(P,V)=(0,0)$, $(P,V)=(1,0)$, and $(P,V)=(0,1)$, with
the shape of the border line from $(1,0)$ to $(0,1)$ depending on the
particular choice for $P$ and the induced definition of $V$.


title:
Meta-Stable Brane Configurations of Multiple Product Gauge Groups with
  Orientifold 6 Plane

abstract:
  Starting from an N=1 supersymmetric electric gauge theory with the gauge
group SU(N_c) x SU(N_c') x SU(N_c'') with fundamentals for each gauge group,
the bifundamentals, a symmetric flavor and a conjugate symmetric flavor for
SU(N_c), we apply Seiberg dual to each gauge group, obtain the N=1
supersymmetric dual magnetic gauge theories with dual matters including the
gauge singlets, and describe the intersecting brane configurations of type IIA
string theory corresponding to the meta-stable nonsupersymmetric vacua of this
gauge theory. We also discuss the case where a symmetric flavor is replaced by
an antisymmetric flavor. Next we apply to the case for N=1 supersymmetric
electric gauge theory with the gauge group SO(N_c) x SU(N_c') x SU(N_c'') with
flavors for each gauge group and the bifundamentals. Finally, we describe the
case where the orientifold 6-plane charge is reversed.


title: Some Generalizations of Fedorchuk Duality Theorem -- II

abstract:
  As it was shown in the first part of this paper, there exists a duality
between the category DSkeLC (introduced there) and the category SkeLC of
locally compact Hausdorff spaces and continuous skeletal maps. We describe here
the subcategories of the category DSkeLC which are dually equivalent to the
following eight categories: all of them have as objects the locally compact
Hausdorff spaces and their morphisms are, respectively, the injective
(respectively, surjective) continuous skeletal maps, the injective (resp.,
surjective) open maps, the injective (resp., surjective) skeletal perfect maps,
the injective (resp., surjective) open perfect maps. The particular cases of
these theorems for the full subcategories of the last four categories having as
objects all compact Hausdorff spaces are formulated and proved. The
DSkeLC-morphisms which are LCA-embeddings and the dense homeomorphic embeddings
are characterized through their dual morphisms. For any locally compact space
X, a description of the frame of all open subsets of X in terms of the dual
object of X is obtained. It is shown how one can build the dual object of an
open subset (respectively, of a regular closed subset) of a locally compact
Hausdorff space X directly from the dual object of X. Applying these results, a
new description of the ordered set of all, up to equivalence, locally compact
Hausdorff extensions of a locally compact Hausdorff space is obtained.
Moreover, generalizing de Vries Compactification Theorem, we strengthen the
Local Compactification Theorem of Leader. Some other applications are found.


title:
The Spatial Distributions of Red and Blue Globular Clusters in Major Dry
  Merger Remnants

abstract:
  Using high-resolution N-body simulations, we examine whether a major dry
merger mitigates the difference in the radial density distributions between red
and blue globular clusters (GCs). To this end, we study the relation between
the density slope of the GCs in merger progenitors and that in a merger
remnant, when the density distribution is described by $n_{\rm GC}\propto
r^{-\alpha}$. We also study how our results depend on the merger orbit and the
size of the core radius of the initial GC density distribution. We find that a
major dry merger makes the GC profile flatter, and the steeper initial GC
profile leads to more significant flattening, especially if the initial slope
is steeper than $\alpha\sim3.5$. Our result suggests that if there is a major
dry merger of elliptical galaxies whose red GCs have a steeper radial profile
than the blue GCs, as currently observed, and their slopes are steeper than
$\alpha\sim3.5$, the difference in the slopes between two populations becomes
smaller after dry mergers. Therefore, the observed slopes of red and blue GCs
can be a diagnostic of the importance of dry merger. The current observational
data show that the red and blue GCs have more comparable and shallower slopes
in some luminous galaxies, which may indicate that they have experienced dry
mergers.


title:
The spectrum of the Leray transform for convex Reinhardt domains in
  $\mathbb C^2$

abstract:
  The Leray transform and related boundary operators are studied for a class of
convex Reinhardt domains in $\mathbb C^2$. Our class is self-dual; it contains
some domains with less than $C^2$-smooth boundary and also some domains with
smooth boundary and degenerate Levi form. $L^2$-regularity is proved, and
essential spectra are computed with respect to a family of boundary measures
which includes surface measure. A duality principle is established providing
explicit unitary equivalence between operators on domains in our class and
operators on the corresponding polar domains. Many of these results are new
even for the classical case of smoothly bounded strongly convex Reinhardt
domains.


title: Scaling of the Lyapunov exponent in type-III intermittent chaos

abstract:
  The scaling behaviour of the Lyapunov exponent near the transition to chaos
via type-III intermittency is determined for a generic map. A critical exponent
$\beta$ expressing the scaling of the Lyapunov exponent as a function of both,
the reinjection probability and the nonlinearity of the map is calculated. It
is found that the critical exponent varies on the interval $0 < \beta < 1$.
This contrasts with earlier predictions for the scaling behaviour of the
Lyapunov exponent in type-III intermittency.


title: Highly Efficient Modeling of Dynamic Coronal Loops

abstract:
  Observational and theoretical evidence suggests that coronal heating is
impulsive and occurs on very small cross-field spatial scales. A single coronal
loop could contain a hundred or more individual strands that are heated
quasi-independently by nanoflares. It is therefore an enormous undertaking to
model an entire active region or the global corona. Three-dimensional MHD codes
have inadequate spatial resolution, and 1D hydro codes are too slow to simulate
the many thousands of elemental strands that must be treated in a reasonable
representation. Fortunately, thermal conduction and flows tend to smooth out
plasma gradients along the magnetic field, so "0D models" are an acceptable
alternative. We have developed a highly efficient model called Enthalpy-Based
Thermal Evolution of Loops (EBTEL) that accurately describes the evolution of
the average temperature, pressure, and density along a coronal strand. It
improves significantly upon earlier models of this type--in accuracy,
flexibility, and capability. It treats both slowly varying and highly impulsive
coronal heating; it provides the differential emission measure distribution,
DEM(T), at the transition region footpoints; and there are options for heat
flux saturation and nonthermal electron beam heating. EBTEL gives excellent
agreement with far more sophisticated 1D hydro simulations despite using four
orders of magnitude less computing time. It promises to be a powerful new tool
for solar and stellar studies.


title: A local version of Gotzmann's Persistence

abstract:
  Gotzmann's Persistence states that the growth of an arbitrary ideal can be
controlled by comparing it to the growth of the lexicographic ideal. This is
used, for instance, in finding equations which cut out the Hilbert scheme (of
subschemes of $\mathbf{P}^n$ with fixed Hilbert polynomial) sitting inside an
appropriate Grassmannian. We introduce the notion of an {\it extremal ideal}
which extends the notion of the lex ideal to other term orders. We then state
and prove a version of Gotzmann's theorem for these ideals, valid in an open
subset of a Grassmannian.


title: A note on \Xi_c(3055)^+ and \Xi_c(3123)^+

abstract:
  Babar Collaboration announced two new excited charmed baryons $\Xi_c(3055)^+$
and $\Xi_c(3123)^+$. We study their strong decays assuming they are D-wave
states. Some assignments are excluded by comparing our numerical results with
the experimental values of the total widths of $\Xi_c(3055)^+$ and
$\Xi_c(3123)^+$. We also suggest some possible decay modes, which will be
helpful to determine the properties of $\Xi_c(3055)^+$ and $\Xi_c(3123)^+$.


title: Stellar Intensity Interferometry with Air Cherenkov Telescope arrays

abstract:
  The present generation of ground-based Very High Energy (VHE) gamma-ray
observatories consist of arrays of up to four large (> 12m diameter) light
collectors quite similar to those used by R. Hanbury Brown to measure stellar
diameters by Intensity Interferometry in the late 60's. VHE gamma-ray
observatories to be constructed over the coming decade will involve several
tens of telescopes of similar or greater sizes. Used as intensity
interferometers, they will provide hundreds of independent baselines. Now is
the right time to re-assess the potential of intensity interferometry so that
it can be taken into consideration in the design of these large facilities.


title:
The Connection Between Low-Mass X-ray Binaries and (Millisecond)
  Pulsars: A Binary Evolution Perspective

abstract:
  I review the evolutionary connection between low-mass X-ray binaries (LMXBs)
and pulsars with binary companions (bPSRs) from a stellar binary evolution
perspective. I focus on the evolution of stellar binaries with end-states
consisting of a pulsar with a low-mass (<1.0 solar mass) companion, starting at
the point the companion's progenitor first initiates mass transfer onto the
neutron star. Whether this mass transfer is stable and the physics driving
ongoing mass transfer partitions the phase space of the companions's initial
mass and initial orbital period into five regions. The qualitative nature of
the mass-transfer process and the binary's final end-state differ between
systems in each region; four of these regions each produce a particular class
of LMXBs. I compare the theoretical expectations to the populations of galactic
field LMXBs with companion-mass constraints and field bPSRs. I show that the
population of accreting millisecond pulsars are all identified with only two of
the four LMXB classes and that these systems do not have readily identifiable
progeny in the bPSR population. I discuss which sub-populations of bPSRs can be
explained by binary evolution theory and those that currently are not. Finally
I discuss some outstanding questions in this field.


title:
The potential for intensity interferometry with gamma-ray telescope
  arrays

abstract:
  Intensity interferometry exploits a quantum optical effect in order to
measure objects with extremely small angular scales. The first experiment to
use this technique was the Narrabri intensity interferometer, which was
successfully used in the 1970s to measure 32 stellar diameters at optical
wavelengths; some as small as 0.4 milli-arcseconds. The advantage of this
technique, in comparison with Michelson interferometers, is that it requires
only relatively crude, but large, light collectors equipped with fast
(nanosecond) photon detectors. Ground-based gamma-ray telescope arrays have
similar specifications, and a number of these observatories are now operating
worldwide, with more extensive installations planned for the future. These
future instruments (CTA, AGIS, completion 2015) with 30-90 telescopes will
provide 400-4000 different baselines that range in length between 50m and a
kilometre. Intensity interferometry with such arrays of telescopes attains $50
\mu$-arcsecond resolution for a limiting visual magnitude ~8.5. Phase
information can be extracted from the interferometric measurement with phase
closure, allowing image reconstruction. This technique opens the possibility of
a wide range of studies amongst others, probing the stellar surface activity
and the dynamic AU scale circumstellar environment of stars in various crucial
evolutionary stages. Here we focuse on the astrophysical potential of an
intensity interferometer utilising planned new gamma-ray instrumentation.


title: Physics Engineering in the Study of the Pioneer Anomaly

abstract:
  The Pioneer 10/11 spacecraft yielded the most precise navigation in deep
space to date. However, their radio-metric tracking data received from the
distances between 20--70 astronomical units from the Sun has consistently
indicated the presence of a small, anomalous, Doppler frequency drift. The
drift is a blue frequency shift that can be interpreted as a sunward
acceleration of a_P = (8.74 +/- 1.33) x 10^{-10} m/s^2 for each particular
spacecraft. This signal has become known as the Pioneer anomaly; the nature of
this anomaly remains unexplained.
  Recently new Pioneer 10 and 11 radio-metric Doppler and flight telemetry data
became available. The newly available Doppler data set is significantly
enlarged when compared to the data used in previous investigations and is
expected to be the primary source for the investigation of the anomaly. In
addition, the flight telemetry files, original project documentation, and newly
developed software tools are now used to reconstruct the engineering history of
both spacecraft. With the help of this information, a thermal model of the
Pioneer vehicles is being developed to study possible contribution of thermal
recoil force acting on the two spacecraft. The ultimate goal of these physics
engineering efforts is to evaluate the effect of on-board systems on the
spacecrafts' trajectories.


title:
Binary quantization using Belief Propagation with decimation over factor
  graphs of LDGM codes

abstract:
  We propose a new algorithm for binary quantization based on the Belief
Propagation algorithm with decimation over factor graphs of Low Density
Generator Matrix (LDGM) codes. This algorithm, which we call Bias Propagation
(BiP), can be considered as a special case of the Survey Propagation algorithm
proposed for binary quantization by Wainwright et al. [8]. It achieves the same
near-optimal rate-distortion performance with a substantially simpler framework
and 10-100 times faster implementation. We thus challenge the widespread belief
that binary quantization based on sparse linear codes cannot be solved by
simple Belief Propagation algorithms. Finally, we give examples of suitably
irregular LDGM codes that work with the BiP algorithm and show their
performance.


title:
Selfdecomposability and semi-selfdecomposability in subordination of
  cone-parameter convolution semigroups

abstract:
  Extension of two known facts concerning subordination is made. The first fact
is that, in subordination of 1-dimensional Brownian motion with drift,
selfdecomposability is inherited from subordinator to subordinated. This is
extended to subordination of cone-parameter convolution semigroups. The second
fact is that, in subordination of strictly stable cone-parameter convolution
semigroups on $\mathbb{R}^d$, selfdecomposability is inherited from
subordinator to subordinated. This is extended to semi-selfdecomposability.


title: Invariant chiral differential operators and the W_3 algebra

abstract:
  Attached to a vector space V is a vertex algebra S(V) known as the beta-gamma
system or algebra of chiral differential operators on V. It is analogous to the
Weyl algebra D(V), and is related to D(V) via the Zhu functor. If G is a
connected Lie group with Lie algebra g, and V is a linear G-representation,
there is an action of the corresponding affine algebra on S(V). The invariant
space S(V)^{g[t]} is a commutant subalgebra of S(V), and plays the role of the
classical invariant ring D(V)^G. When G is an abelian Lie group acting
diagonally on V, we find a finite set of generators for S(V)^{g[t]}, and show
that S(V)^{g[t]} is a simple vertex algebra and a member of a Howe pair. The
Zamolodchikov W_3 algebra with c=-2 plays a fundamental role in the structure
of S(V)^{g[t]}.


title:
Protection of New York City Urban Fabric With Low-Cost Textile Storm
  Surge Barriers

abstract:
  Textile storm surge barriers, sited at multiple locations, are literally
extensions of the city world famous urban fabric - another manifestation of the
dominance of the City over local Nature. Textile Storm Surge Barriers (TSSB)
are intended to preserve the City from North Atlantic Ocean hurricanes that
cause sea waves impacting the densely populated and high-value real estate,
instigating catastrophic, and possibly long-term, infrastructure and monetary
losses. Complicating TSSB installation macroproject planning is the presence of
the Hudson and other rivers, several small tidal straits, future climate change
and other factors. We conclude that TSSB installations made of homogeneous
construction materials are worthwhile investigating because they may be less
expensive to build, and more easily replaced following any failure, than
concrete and steel storm surge barriers, which are also made of homogeneous
materials. We suppose the best macroproject outcome will develop in the perfect
Macro-engineering planning way and at the optimum time-of-need during the very
early 21st Century by, among other groups, the Port Authority of New York and
New Jersey. TSSB technology is a practical advance over wartime harbor
anti-submarine/anti-torpedo steel nets and rocky Churchill Barriers.


title:
Faddeev calculation of pentaquark $\Theta^+$ in the Nambu-Jona-Lasinio
  model-based diquark picture

abstract:
  A Bethe-Salpeter-Faddeev (BSF) calculation is performed for the pentaquark
$\Theta^+$ in the diquark picture of Jaffe and Wilczek in which $\Theta^+$ is a
diquark-diquark-${\bar s}$ three-body system. Nambu-Jona-Lasinio (NJL) model is
used to calculate the lowest order diagrams in the two-body scatterings of
${\bar s}D$ and $D D$. With the use of coupling constants determined from the
meson sector, we find that ${\bar s}D$ interaction is attractive in s-wave
while $DD$ interaction is repulsive in p-wave. With only the lowest three-body
channel considered, we do not find a bound $ \frac 12^+$ pentaquark state.
Instead, a bound pentaquark $\Theta^+$ with $ \frac 12^-$ is obtained with a
unphysically strong vector mesonic coupling constants.


title: The Watch Paradox: Solution of the Problem

abstract:
  The article presents the detailed analysis of the watch paradox. It is shown
that it arose because of unjustified, as it turned out, identification of watch
readings at the moment of its return with the time read by it.


title: Z4-Linear Perfect Codes

abstract:
  For every $n = 2^k > 8$ there exist exactly $[(k+1)/2]$ mutually
nonequivalent $Z_4$-linear extended perfect codes with distance 4. All these
codes have different ranks.


title: Z4-linear Hadamard and extended perfect codes

abstract:
  If $N=2^k > 8$ then there exist exactly $[(k-1)/2]$ pairwise nonequivalent
$Z_4$-linear Hadamard $(N,2N,N/2)$-codes and $[(k+1)/2]$ pairwise nonequivalent
$Z_4$-linear extended perfect $(N,2^N/2N,4)$-codes. A recurrent construction of
$Z_4$-linear Hadamard codes is given.


title:
Intrinsic dissipation in nanomechanical resonators due to phonon
  tunneling

abstract:
  State of the art nanomechanical resonators present quality factors Q ~ 10^3 -
10^5, which are much lower than those that can be naively extrapolated from the
behavior of micromechanical resonators. We analyze the dissipation mechanism
that arises in nanomechanical beam-structures due to the tunneling of
mesoscopic phonons between the beam and its supports (known as clamping
losses). We derive the environmental force spectral density that determines the
quantum Brownian motion of a given resonance. Our treatment is valid for low
frequencies and provides the leading contribution in the aspect ratio. This
yields fundamental limits for the Q-values which are described by simple
scaling laws and are relevant for state of the art experimental structures. In
this context, for resonant frequencies in the 0.1-1GHz range, while this
dissipation mechanism can limit flexural resonators it is found to be
negligible for torsional ones. In the case of structureless 3D supports the
corresponding environmental spectral densities are Ohmic for flexural
resonators and super-Ohmic for torsional ones, while for 2D slab supports they
yield 1/f noise. Furthermore analogous results are established for the case of
suspended semiconducting single-walled carbon nanotubes. Finally, we provide a
general expression for the spectral density that allows to extend our treatment
to other geometries and illustrate its use by applying it to a microtoroid. Our
analysis is relevant for applications in high precision measurements and for
the prospects of probing quantum effects in a macroscopic mechanical degree of
freedom.


title: A note on free quantum groups

abstract:
  We study the free complexification operation for compact quantum groups,
$G\to G^c$. We prove that, with suitable definitions, this induces a one-to-one
correspondence between free orthogonal quantum groups of infinite level, and
free unitary quantum groups satisfying $G=G^c$.


title:
Stylized Facts Generated Through Cellular Automata Models. Case of
  Study: The Game of Life

abstract:
  In the present work, a geometrical method to generate a two dimensional
random walk by means of a bidimensional Cellular Automaton is presented. We
illustrate it by means of Conway's Game of Life with periodical borders, with a
large lattice of 3000 x 3000 cells. The obtained random walk is of character
anomalous, and its projection to a one dimensional random walk is analyzed,
showing that it presents some statistical properties similar to the so-called
stylized facts observed in financial time series. We consider that the
procedure presented here is important not only because of its simplicity, but
also because it could help us to understand and shed light on the stylized
facts formation mechanism.


title:
Double Parton Scattering in Associate Higgs Boson Production with Bottom
  Quarks at Hadron Colliders

abstract:
  Higgs boson production in association with bottom quarks, is one of the most
important discovery channels for Higgs particles in the Standard Model (SM) and
its supersymmetric extension at the LHC pp collider . The theoretical
prediction of the corresponding cross section has been improved by including
the complete next-to-leading order QCD corrections. We review the status
results for the leading order to the partonic process and present calculations
for the integrated cross-section in both single and double parton scattering
collisions.


title: Study of constant mode in charmonium correlators at finite temperature

abstract:
  Recent studies on the spectral function of charmonium in lattice QCD suggest
survival of $J/\psi$ state in the deconfinement phase till relatively high
temperature. Based on the studies, different scenarios of $J/\psi$ suppression
are discussed to understand experimental results in the Heavy Ion Collision
experiments. The scenarios require the information on the dissociation
temperatures of $\chi_c$ and $\psi'$ as well as that of $J/\psi$. In order to
investigate these states in finite temperature lattice QCD, we have to consider
an effect of a characteristic constant mode in the correlators. As a result of
the study on the constant mode, we find that most drastic change in charmonium
correlators for $\chi_c$ states just above the deconfinement transition are
caused by the constant mode. It may indicate the survival of $\chi_c$ states
after the deconfinement transition until, at least, $1.4T_c$.


title: A GEM TPC End-Panel Pre-Prototype

abstract:
  A GEM TPC end panel pre-prototype was constructed for a large LC-TPC
prototype to test its basic design philosophy and some of its engineering
details. Its interim test results are presented.


title:
A Survey for Massive Giant Planets in Debris Disks with Evacuated Inner
  Cavities

abstract:
  The commonality of collisionally replenished debris around main sequence
stars suggests that minor bodies are frequent around Sun-like stars. Whether or
not debris disks in general are accompanied by planets is yet unknown, but
debris disks with large inner cavities - perhaps dynamically cleared - are
considered to be prime candidates for hosting large-separation massive giant
planets. We present here a high-contrast VLT/NACO angular differential imaging
survey for eight such cold debris disks. We investigated the presence of
massive giant planets in the range of orbital radii where the inner edge of the
dust debris is expected. Our observations are sensitive to planets and brown
dwarfs with masses >3 to 7 Jupiter mass, depending on the age and distance of
the target star. Our observations did not identify any planet candidates. We
compare the derived planet mass upper limits to the minimum planet mass
required to dynamically clear the inner disks. While we cannot exclude that
single giant planets are responsible for clearing out the inner debris disks,
our observations constrain the parameter space available for such planets. The
non-detection of massive planets in these evacuated debris disks further
reinforces the notion that the giant planet population is confined to the inner
disk (<15 AU).


title:
Medium-separation binaries do not affect the first steps of planet
  formation

abstract:
  The first steps of planet formation are marked by the growth and
crystallization of sub-micrometer-sized dust grains accompanied by dust
settling toward the disk midplane. In this paper we explore whether the first
steps of planet formation are affected by the presence of medium-separation
stellar companions. We selected two large samples of disks around single and
binary T Tauri stars in Taurus that are thought to have only a modest age
spread of a few Myr. The companions of our binary sample are at projected
separations between 10 and 450 AU with masses down to about 0.1 solar masses.
We used the strength and shape of the 10 micron silicate emission feature as a
proxy for grain growth and for crystallization respectively. The degree of dust
settling was evaluated from the ratio of fluxes at two different mid-infrared
wavelengths. We find no statistically significant difference between the
distribution of 10 micron silicate emission features from single and binary
systems. In addition, the distribution of disk flaring is indistinguishable
between the single and binary system samples. These results show that the first
steps of planet formation are not affected by the presence of a companion at
tens of AU.


title:
Hanbury Brown and Twiss correlations in atoms scattered from colliding
  condensates

abstract:
  Low energy elastic scattering between clouds of Bose condensed atoms leads to
the well known s-wave halo with atoms emerging in all directions from the
collision zone. In this paper we discuss the emergence of Hanbury Brown and
Twiss coincidences between atoms scattered in nearly parallel directions. We
develop a simple model that explains the observations in terms of an
interference involving two pairs of atoms each associated with the elementary s
wave scattering process.


title: Parton Equilibration Enforcing Baryon Number Conservation

abstract:
  Parton equilibration for a thermally equilibrated but chemically
non-equilibrated quark gluon plasma is presented. Parton equilibration is
studied enforcing baryon numbver conservation. Process like quark flavour
interchanging is also considered. The degree of equilibration is studied
comparatively for the various reactions / constraints that are being
considered.


title: Viscous dark fluid

abstract:
  The unified dark energy and dark matter model within the framework of a model
of a continuous medium with bulk viscosity (dark fluid) is considered. It is
supposed that the bulk viscosity coefficient is an arbitrary function of the
Hubble parameter. The choice of this function is carried out under the
requirement to satisfy the observational data from recombination ($z\approx
1000$) till present time.


title:
Nonlocality of Dephasing in a Charge Qubit Interacting with a Quantum
  Point Contact Beam Collider

abstract:
  We investigate the charge-detection-induced dephasing of a charge qubit
interacting with an electronic beam collider composed of a quantum point
contact. We report that, while the qubit is dephased by the partitioned beam of
uncorrelated electrons, the interference of the qubit is fully restored when
the two inputs are identically biased so that all the electrons suffer
two-electron collision. This phenomenon is related to Fermi statistics and
illustrates the peculiar nonlocality of dephasing. We also describe detection
properties for the injection of entangled electron pairs.


title:
Linear oscillations of a compressible hemispherical bubble on a solid
  substrate

abstract:
  The linear natural and forced oscillations of a hemispherical bubble on a
solid substrate are under theoretical consideration. The contact line dynamics
is taken into account with the Hocking condition, which eventually leads to
interaction of the shape and volume oscillations. Resonant phenomena, mostly
pronounced for the bubble with the fixed contact line or with the fixed contact
angle, are found out. The limiting case of weakly compressible bubble is
studied. The general criterion identifying whether the compressibility of a
bubble can be neglected is obtained.


title: Optimising the topology of complex neural networks

abstract:
  In this paper, we study instances of complex neural networks, i.e. neural
netwo rks with complex topologies. We use Self-Organizing Map neural networks
whose n eighbourhood relationships are defined by a complex network, to
classify handwr itten digits. We show that topology has a small impact on
performance and robus tness to neuron failures, at least at long learning
times. Performance may howe ver be increased (by almost 10%) by artificial
evolution of the network topo logy. In our experimental conditions, the evolved
networks are more random than their parents, but display a more heterogeneous
degree distribution.


title: Curvature corrections in DGP brane cosmology

abstract:
  We consider a DGP inspired brane scenario where the action on the brane is
augmented by a function of the Ricci scalar, ${\cal L}(R)$. The cosmological
implications that such a scenario entails are examined for $R^{n}$ and shown to
be consistent with a universe expanding with power-law acceleration. It is
shown that two classes of solutions exist for the usual FRW metric and small
Hubble radii. When the Hubble radius becomes larger, we either have a
transition to a fully 5D regime or to a self-inflationary solution which
produces a late accelerated expansion such that the radius becomes a function
of $n$.


title:
Correlation effects on magnetic frustration in the triangular-lattice
  Hubbard model

abstract:
  Evolution of the magnetic response function in the triangular-lattice Hubbard
model is studied with interaction strength within a systematic
inverse-degeneracy expansion scheme which incorporates self-energy and vertex
corrections and explicitly preserves the spin-rotation symmetry. It is shown
that at half filling the response function goes through a nearly dispersionless
regime around K for intermediate coupling strength, before undergoing an
inversion at strong coupling, resulting in maximum response at the K point,
consistent with the expected 120^o AF instability. Effects of finite
hole/electron doping on the magnetic response function are also examined.


title: SUSY Quantum Hall Effect on Non-Anti-Commutative Geometry

abstract:
  We review the recent developments of the SUSY quantum Hall effect
[hep-th/0409230, hep-th/0411137, hep-th/0503162, hep-th/0606007,
arXiv:0705.4527]. We introduce a SUSY formulation of the quantum Hall effect on
supermanifolds. On each of supersphere and superplane, we investigate SUSY
Landau problem and explicitly construct SUSY extensions of Laughlin
wavefunction and topological excitations. The non-anti-commutative geometry
naturally emerges in the lowest Landau level and brings particular physics to
the SUSY quantum Hall effect. It is shown that SUSY provides a unified picture
of the original Laughlin and Moore-Read states. Based on the charge-flux
duality, we also develop a Chern-Simons effective field theory for the SUSY
quantum Hall effect.


title: Anomalous dimensions of finite size field strength operators in N=4 SYM

abstract:
  In the N=4 super Yang-Mills theory, we consider the higher order anomalous
dimensions gamma_L(g) of purely gluonic operators Tr(F^L) where F is a
component of the self-dual field strength. We propose compact closed
expressions depending parametrically on L that reproduce the prediction of
Bethe Ansatz equations up to five loop order, including transcendental dressing
corrections. The size dependence follows a simple pattern as the perturbative
order is increased and suggests hidden relations for these special operators.


title: An affine sphere equation associated to Einstein toric surfaces

abstract:
  As seen in the works of Calabi, Cheng-Yau and Loftin, affine sphere equations
have a close relationship with Kaehler-Einstein metrics. The main purpose of
this note is to show that an equation analogous to those of hyperbolic affine
spheres arises naturally from Kaehler-Einstein metrics on Einstein toric
surfaces. The case for the remaining toric surfaces with Kaehler-Ricci solitons
will also be discussed.


title:
Exact thermodynamics of a planar array of Ginzburg-Landau chains with nn
  and nnn interactions

abstract:
  The exact expression of the free energy of a planar array of a
Ginzburg-Landau chains with nn and nnn interaction is obtained. The critical
behaviour of the specific heat is not qualitatively modified by taking into
account the nnn interaction.


title:
Can magnetism-assisted quasiperiodic structures in Russell-FeS `bubbles'
  offer a quantum coherent origin of life?

abstract:
  This paper seeks to expand the scope of the alkaline seepage site
hydrothermal mound scenario of Russell et al, by appealing to its wider canvas
for hypothesizing self-assembly of gregite clusters via interplay of forces
within the gel phase of FeS membranes: directed heat transport a la
Rayleigh-Benard convection for dissociation, vs oriented attachment (small
clusters) and magnetic forces (large clusters) for association, the latter
assisted by magnetic mound constituents. The directed movement of tiny clusters
through cluster layers are reminiscent of processes like budding, molecular
motors, pre-RNA world on the lines of Cairns-Smith's hypothesis, and optical
polarity. Higher rate of (soft) multinucleate formation vs growth rate of
(rigid) microcrystals, correlates with icosahedral (forbidden
crystallographically!) framboidal morphology. This pattern indicates a link to
phylotaxis, thus reinforcing the quasi-periodicity connection which can provide
a natural access to features like surface limit, anomalous transport and low
thermal conductivity, while facilitating diffusion through clusters. And
magnetism offers a hierarchy of features: primordial multicellularity; phase
correlations of assembled molecules; overcoming thermal decoherence. These
dynamical nested structures offer possibilities for iterative computations,
adaptive learning, and coherent quantum searches. The link between enzymatic
FeS clusters and the Hadean ocean floor is seen as part of a larger conceptual
framework uncovering a role for Magnetism and the Origin of Life.


title: A Note on Separability of Field Equations in Myers-Perry Spacetimes

abstract:
  We study separability of scalar, vector and tensor fields in 5-dimensional
Myers-Perry spacetimes with equal angular momenta. In these spacetimes, there
exists enlarged symmetry, $U(2) \simeq SU(2) \times U(1)$. Using the group
theoretical method with a twist, we perform the dimensional reduction at the
action level and show that both vector and tensor field equations can be
reduced to coupled ordinary differential equations. We reveal the structure of
couplings between variables. In particular, we have obtained the decoupled
master equations for zero modes of a vector field. The same analysis can be
done for zero modes of a tensor field. Therefore, our formalism gives a basis
for studying stability of Myers-Perry black holes.


title:
Dequantized Differential Operators between Tensor Densities as Modules
  over the Lie Algebra of Contact Vector Fields

abstract:
  In recent years, algebras and modules of differential operators have been
extensively studied. Equivariant quantization and dequantization establish a
tight link between invariant operators connecting modules of differential
operators on tensor densities, and module morphisms that connect the
corresponding dequantized spaces. In this paper, we investigate dequantized
differential operators as modules over a Lie subalgebra of vector fields that
preserve an additional structure. More precisely, we take an interest in
invariant operators between dequantized spaces, viewed as modules over the Lie
subalgebra of infinitesimal contact or projective contact transformations. The
principal symbols of these invariant operators are invariant tensor fields. We
first provide full description of the algebras of such affine-contact- and
contact-invariant tensor fields. These characterizations allow showing that the
algebra of projective-contact-invariant operators between dequantized spaces
implemented by the same density weight, is generated by the vertical cotangent
lift of the contact form and a generalized contact Hamiltonian. As an
application, we prove a second key-result, which asserts that the Casimir
operator of the Lie algebra of infinitesimal projective contact
transformations, is diagonal. Eventually, this upshot entails that invariant
operators between spaces induced by different density weights, are made up by a
small number of building bricks that force the parameters of the source and
target spaces to verify Diophantine-type equations.


title: Topological expansion and boundary conditions

abstract:
  In this article, we compute the topological expansion of all possible
mixed-traces in a hermitian two matrix model. In other words we give a recipe
to compute the number of discrete surfaces of given genus, carrying an Ising
model, and with all possible given boundary conditions. The method is
recursive, and amounts to recursively cutting surfaces along interfaces. The
result is best represented in a diagrammatic way, and is thus rather simple to
use.


title: Extension and estimation of correlations in Cold Dark Matter models

abstract:
  We discuss the large scale properties of standard cold dark matter
cosmological models characterizing the main features of the power-spectrum, of
the two-point correlation function and of the mass variance. Both the
real-space statistics have a very well defined behavior on large enough scales,
where their amplitudes become smaller than unity. The correlation function, in
the range 0<\xi(r)<1, is characterized by a typical length-scale r_c, at which
\xi(r_c)=0, which is fixed by the physics of the early universe: beyond this
scale it becomes negative, going to zero with a tail proportional to -(r^{-4}).
These anti-correlations represent thus an important observational challenge to
verify models in real space. The same length scale r_c characterizes the
behavior of the mass variance which decays, for r>r_c, as r^{-4}, the fastest
decay for any mass distribution. The length-scale r_c defines the maximum
extension of (positively correlated) structures in these models. These are the
features expected for the dark matter field: galaxies, which represent a biased
field, however may have differences with respect to these behaviors, which we
analyze. We then discuss the detectability of these real space features by
considering several estimators of the two-point correlation function. By making
tests on numerical simulations we emphasize the important role of finite size
effects which should always be controlled for careful measurements.


title: On the role of autocorrelations in texts

abstract:
  The task of finding a criterion allowing to distinguish a text from an
arbitrary set of words is rather relevant in itself, for instance, in the
aspect of development of means for internet-content indexing or separating
signals and noise in communication channels. The Zipf law is currently
considered to be the most reliable criterion of this kind [3]. At any rate,
conventional stochastic word sets do not meet this law. The present paper deals
with one of possible criteria based on the determination of the degree of data
compression.


title: How Far Should the Principle of Relativity Go ?

abstract:
  The Principle of Relativity has so far been understood as the {\it
covariance} of laws of Physics with respect to a general class of reference
frame transformations. That relativity, however, has only been expressed with
the help of {\it one single} type of mathematical entities, namely, the scalars
given by the usual continuum of the field $\mathbb{R}$ of real numbers, or by
the usual mathematical structures built upon $\mathbb{R}$, such as the scalars
given by the complex numbers $\mathbb{C}$, or the vectors in finite dimensional
Euclidean spaces $\mathbb{R}^n$, infinite dimensional Hilbert spaces, etc.
  This paper argues for {\it progressing deeper and wider} in furthering the
Principle of Relativity, not by mere covariance with respect to reference
frames, but by studying the possible covariance with respect to a {\it large
variety} of algebras of scalars which extend significantly $\mathbb{R}$ or
$\mathbb{C}$, variety of scalars in terms of which various theories of Physics
can equally well be formulated.
  First directions in this regard can be found naturally in the simple
Mathematics of Special Relativity, the Bell Inequalities in Quantum Mechanics,
or in the considerable amount of elementary Mathematics in finite dimensional
vector spaces which occurs in Quantum Computation.
  The large classes of algebras of scalars suggested, which contain
$\mathbb{R}$ and $\mathbb{C}$ as particular cases, have the important feature
of typically {\it no longer} being Archimedean, see Appendix, a feature which
can prove to be valuable when dealing with the so called "infinities" in
Physics.
  The paper has a Comment on the so called "end of time".


title: A model for chaotic dielectric microresonators

abstract:
  We develop a random-matrix model of two-dimensional dielectric resonators
which combines internal wave chaos with the deterministic Fresnel laws for
reflection and refraction at the interfaces. The model is used to investigate
the statistics of the laser threshold and line width (lifetime and Petermann
factor of the resonances) when the resonator is filled with an active medium.
The laser threshold decreases for increasing refractive index $n$ and is
smaller for TM polarization than for TE polarization, but is almost independent
of the number of out-coupling modes $N$. The Petermann factor in the line width
of the longest-living resonance also decreases for increasing $n$ and scales as
$\sqrt{N}$, but is less sensitive to polarization. For resonances of
intermediate lifetime, the Petermann factor scales linearly with $N$. These
qualitative parametric dependencies are consistent with the random-matrix
theory of resonators with small openings. However, for a small refractive index
where the resonators are very open, the details of the statistics become
non-universal. This is demonstrated by comparison with a particular dynamical
model.


title:
On the fractal nature of mutual relevance sequences in the Internet news
  message flows

abstract:
  In the task of information retrieval the term relevance is taken to mean
formal conformity of a document given by the retrieval system to user's
information query. As a rule, the documents found by the retrieval system
should be submitted to the user in a certain order. Therefore, a retrieval
perceived as a selection of documents formally solving the user's query, should
be supplemented with a certain procedure of processing a relevant set. It would
be natural to introduce a quantitative measure of document conformity to query,
i.e. the relevance measure. Since no single rule exists for the determination
of the relevance measure, we shall consider two of them which are the simplest
in our opinion. The proposed approach does not suppose any restrictions and can
be applied to other relevance measures.


title:
Transverse and longitudinal momentum spectra of fermions produced in
  strong SU(2) fields

abstract:
  We study the transverse and longitudinal momentum spectra of fermions
produced in a strong, time-dependent non-Abelian SU(2) field. Different
time-dependent field strengths are introduced. The momentum spectra are
calculated for the produced fermion pairs in a kinetic model. The obtained
spectra are similar to the Abelian case, and they display exponential or
polynomial behaviour at high p_T, depending on the given time dependence. We
investigated different color initial conditions and discuss the recognized
scaling properties for both Abelian and SU(2) cases.


title: Marking up lattice QCD configurations and ensembles

abstract:
  QCDml is an XML-based markup language designed for sharing QCD configurations
and ensembles world-wide via the International Lattice Data Grid (ILDG). Based
on the latest release, we present key ingredients of the QCDml in order to
provide some starting points for colleagues in this community to markup
valuable configurations and submit them to the ILDG.


title:
Reply to Comment on ``Spherical 2+p spin-glass model: an analytically
  solvable model with a glass-to-glass transition''

abstract:
  In his Comment, Krakoviack [Phys. Rev. B (2007)] finds that the phase
behavior of the s+p spin-glass model is different from what proposed by
Crisanti and Leuzzi [Phys. Rev. B 73, 014412 (2006)] if s and p are larger than
two and are separated well enough. He proposes a trial picture, based on a one
step replica symmetry breaking solution, displaying a mode-coupling-like
glass-to-glass transition line ending in a A3 singularity. However, actually,
the physics of these systems changes when p-s is large, the instability of
which the one step replica symmetry breaking glassy phase suffers turns out to
be so wide ranging that the whole scenario proposed by Krakoviack must be
seriously reconsidered.


title:
Constructing a uniform plane-filling path in the ternary heptagrid of
  the hyperbolic plane

abstract:
  In this paper, we distinguish two levels for the plane-filling property. We
consider a simple and a strong one. In this paper, we give the construction
which proves that the simple plane-filling property also holds for the
hyperbolic plane. The plane-filling property was established for the Euclidean
plane by J. Kari, in 1994, in the strong version.


title: Inertial mechanism: dynamical mass as a source of particle creation

abstract:
  A kinetic theory of vacuum particle creation under the action of an inertial
mechanism is constructed within a nonpertrubative dynamical approach. At the
semi-phenomenological level, the inertial mechanism corresponds to quantum
field theory with a time-dependent mass. At the microscopic level, such a
dependence may be caused by different reasons: The non-stationary Higgs
mechanism, the influence of a mean field or condensate, the presence of the
conformal multiplier in the scalar-tensor gravitation theory etc. In what
follows, a kinetic theory in the collisionless approximation is developed for
scalar, spinor and massive vector fields in the framework of the oscillator
representation, which is an effective tool for transition to the quasiparticle
description and for derivation of non-Markovian kinetic equations. Properties
of these equations and relevant observables (particle number and energy
densities, pressure) are studied. The developed theory is applied here to
describe the vacuum matter creation in conformal cosmological models and
discuss the problem of the observed number density of photons in the cosmic
microwave background radiation. As other example, the self-consistent evolution
of scalar fields with non-monotonic self-interaction potentials (the
W-potential and Witten - Di Vecchia - Veneziano model) is considered. In
particular, conditions for appearance of tachyonic modes and a problem of the
relevant definition of a vacuum state are considered.


title:
Sharp nonremovability examples for H\"older continuous quasiregular
  mappings in the plane

abstract:
  Let $\alpha\in(0,1)$, $K\geq 1$, and $d=2\frac{1+\alpha K}{1+K}$. Given a
compact set $E\subset\C$, it is known that if $\H^d(E)=0$ then $E$ is removable
for $\alpha$-H\"older continuous $K$-quasiregular mappings in the plane. The
sharpness of the index $d$ is shown with the construction, for any $t>d$, of a
set $E$ of Hausdorff dimension $\dim(E)=t$ which is not removable. In this
paper, we improve this result and construct compact nonremovable sets $E$ such
that $0<\H^d(E)<\infty$. For the proof, we give a precise planar
$K$-quasiconformal mapping whose H\"older exponent is strictly bigger than
$\frac{1}{K}$, and that exhibits extremal distortion properties.


title: Rare Decays in Theories with LGS

abstract:
  Gravitational decays in particle physics are expected to violate the B and L
quantum numbers. In the standard theory, where gravity is weak because of the
huge value of Planck mass, the observation of the phenomenon is far from
present and probably future experimental sensitivity. On the other hand, in
theories with low gravity scale, where gravity becomes stronger at shorter
distances, these processes may be dangerous, predicting a too short proton
lifetime. Here I discuss a possible picture of gravitational decays, which is
consistent with present experimental bounds for a true gravity scale of few TeV
and suggests the possibility of observing B and L violating decays with a minor
improvement of the present experimental capability.


title: Branching diffusions, superdiffusions and random media

abstract:
  Spatial branching processes became increasingly popular in the past decades,
not only because of their obvious connection to biology, but also because
superprocesses are intimately related to nonlinear partial differential
equations. Another hot topic in today's research in probability theory is
`random media', including the now classical problems on `Brownian motion among
obstacles' and the more recent `random walks in random environment' and
`catalytic branching' models. These notes aim to give a gentle introduction
into some topics in spatial branching processes and superprocesses in
deterministic environments (sections 2-6) and in random media (sections 7-11).


title:
Fourier method for one dimensional Schr\"odinger operators with singular
  periodic potentials

abstract:
  By using quasi--derivatives, we develop a Fourier method for studying the
spectral properties of one dimensional Schr\"odinger operators with periodic
singular potentials.


title:
Superconductivity in the attractive Hubbard model: functional
  renormalization group analysis

abstract:
  We present a functional renormalization group analysis of superconductivity
in the ground state of the attractive Hubbard model on a square lattice.
Spontaneous symmetry breaking is treated in a purely fermionic setting via
anomalous propagators and anomalous effective interactions. In addition to the
anomalous interactions arising already in the reduced BCS model, effective
interactions with three incoming legs and one outgoing leg (and vice versa)
occur. We accomplish their integration into the usual diagrammatic formalism by
introducing a Nambu matrix for the effective interactions. From a random-phase
approximation generalized through use of this matrix we conclude that the
impact of the 3+1 effective interactions is limited, especially considering the
effective interactions important for the determination of the order parameter.
The exact hierarchy of flow equations for one-particle irreducible vertex
functions is truncated on the two-particle level, with higher-order self-energy
corrections included in a scheme proposed by Katanin. Using a parametrization
of effective interactions by patches in momentum space, the flow equations can
be integrated numerically to the lowest scales without encountering
divergences. Momentum-shell as well as interaction-flow cutoff functions are
used, including a small external field or a large external field and a
counterterm, respectively. Both approaches produce momentum-resolved order
parameter values directly from the microscopic model. The size of the
superconducting gap is in reasonable agreement with expectations from other
studies.


title: Lagrangian description of world-line deviations

abstract:
  We introduce a Lagrangian which can be varied to give both the equation of
motion and world-line deviations of spinning particles simultaneously.


title:
Field patterns in periodically modulated optical parametric amplifiers
  and oscillators

abstract:
  Spatially localized and periodic field patterns in periodically modulated
optical parametric amplifiers and oscillators are studied. In the degenerate
case (equal signal and idler beams) we elaborate the systematic method of
construction of the stationary localized modes in the amplifiers, study their
properties and stability. We describe a method of constructing periodic
solutions in optical parametric oscillators, by adjusting the form of the
external driven field to the given form of either signal or pump beams.


title: Adapted Downhill Simplex Method for Pricing Convertible Bonds

abstract:
  The paper is devoted to modeling optimal exercise strategies of the behavior
of investors and issuers working with convertible bonds. This implies solution
of the problems of stock price modeling, payoff computation and min-max
optimization.
  Stock prices (underlying asset) were modeled under the assumption of the
geometric Brownian motion of their values. The Monte Carlo method was used for
calculating the real payoff which is the objective function. The min-max
optimization problem was solved using the derivative-free Downhill Simplex
method.
  The performed numerical experiments allowed to formulate recommendations for
the choice of appropriate size of the initial simplex in the Downhill Simplex
Method, the number of generated trajectories of underlying asset, the size of
the problem and initial trajectories of the behavior of investors and issuers.


title:
High-fidelity continuous-variable quantum teleportation toward
  multi-step quantum operations

abstract:
  The progress in quantum operations of continuous-variable (CV) schemes can be
reduced to that in CV quantum teleportation. The fidelity of quantum
teleportation of an optical setup is limited by the finite degree of quantum
correlation which can be prepared with a pair of finitely squeezed states.
Reports of improvement of squeezing level have appeared recently, and we
adopted the improved methods in our experimental system of quantum
teleportation. As a result, we teleported a coherent state with a fidelity
$F=0.83\pm 0.01$, which is better than any other figures reported to date. In
this paper, we introduce a measure $n_{s}$, the number of teleportations
expected to be carried out sequentially. Our result corresponds to
$n_{s}$=5.0$\pm$0.4. It suggests that our improvement would enable us to
proceed toward more advanced quantum operations involving multi-step quantum
operations.