title: Biases in Virial Black Hole Masses: An SDSS Perspective

abstract:
  We compile black hole (BH) masses for $\sim 60,000$ quasars in the redshift
range $0.1 \lesssim z \lesssim 4.5$ included in the Fifth Data Release of the
Sloan Digital Sky Survey (SDSS), using virial BH mass estimators based on the
\hbeta, \MgII, and \CIV emission lines. We find that: (1) within our sample,
the widths of the three lines follow log-normal distributions, with means and
dispersions that do not depend strongly on luminosity or redshift;(2) the
\MgII- and \hbeta-estimated BH masses are consistent with one another; and (3)
the \CIV BH mass estimator may be more severely affected by a disk wind
component than the \MgII and \hbeta estimators, giving a positive bias in mass
correlated with the \CIV-\MgII blueshift. Most SDSS quasars have virial BH
masses in the range $10^8-10^9 M_\odot$. There is a clear upper mass limit of
$\sim 10^{10} M_\odot$ for active BHs at $z \gtrsim 2$, decreasing at lower
redshifts. Making the reasonable assumptions that the underlying BH mass
distribution decreases with mass and that the Eddington ratio distribution at
fixed BH mass has non-zero width, we show that the measured virial BH mass
distribution and Eddington ratio distribution are subject to Malmquist bias. A
radio quasar subsample (with $1.5\lesssim z\lesssim 2.3$) has mean virial BH
mass larger by $\sim 0.12$ dex than the whole sample. A broad absorption line
(BAL) quasar subsample (with $1.7\lesssim z\lesssim 2.2$) has identical virial
mass distribution as the nonBAL sample, with no mean offset. (Abridged)


title:
Emil Rupp, Albert Einstein and the canal ray experiments on
  wave-particle duality: Scientific fraud and theoretical bias

abstract:
  In 1926 Emil Rupp published a number of papers on the interference properties
of light emitted by canal ray sources. These articles, particularly one paper
that came into being in collaboration with Albert Einstein, drew quite some
attention as they probed the wave versus particle nature of light. They also
significantly propelled Rupp's career, even though that from the outset they
were highly controversial. This article will review this episode, and in
particular Rupp's collaboration with Einstein. Evidence that Rupp forged his
results is presented and their critical reception in the socially and
politically divided German physics community is discussed. These divisions fail
to explain the full dynamic; the latter is attempted by turning to the role
that theoretical bias on occasion has in assessing experiment. Einstein's
responses in particular are analyzed in this context.


title: The Neutron EDM Experiment

abstract:
  The neutron EDM experiment has played an important part over many decades in
shaping and constraining numerous models of CP violation. This review article
discusses some of the techniques used to calculate EDMs under various
theoretical scenarios, and highlights some of the implications of EDM limits
upon such models. A pedagogical introduction is given to the experimental
techniques employed in the recently completed ILL experiment, including a brief
discussion of the dominant systematic uncertainties. A new and much more
sensitive version of the experiment, which is currently under development, is
also outlined.


title: Is our Sun a Singleton?

abstract:
  Most stars are formed in a cluster or association, where the number density
of stars can be high. This means that a large fraction of initially-single
stars will undergo close encounters with other stars and/or exchange into
binaries. We describe how such close encounters and exchange encounters can
affect the properties of a planetary system around a single star. We define a
singleton as a single star which has never suffered close encounters with other
stars or spent time within a binary system. It may be that planetary systems
similar to our own solar system can only survive around singletons. Close
encounters or the presence of a stellar companion will perturb the planetary
system, often leaving planets on tighter and more eccentric orbits. Thus
planetary systems which initially resembled our own solar system may later more
closely resemble some of the observed exoplanet systems.


title: Cosmology and the Unexpected

abstract:
  In these two lectures I will discuss some outstanding problems in the
standard model of cosmology, concentrating on the physics that might be related
to the title of this school, ``Searching for the totally unexpected in the LHC
era.'' In particular, I will concentrate on dark energy, dark matter, and
inflation.


title:
[OIII] 5007 Emission from the Black-Hole X-ray Binary in a NGC 4472
  Globular Cluster

abstract:
  We present the discovery of [OIII] 5007 emission associated with the black
hole X-ray binary recently identified in a globular cluster in the Virgo
elliptical galaxy NGC 4472. This object is the first confirmed black-hole X-ray
binary in a globular cluster. The identification of [OIII] 5007 emission from
the black-hole hosting globular cluster is based on two independent fiber
spectra obtained at the VLT with FLAMES, which cover a wavelength range of
5000-5800 Angstrom at a spectral resolution of about 6000. In each of these
spectra we find an emission line at 5031.2 Angstrom with an uncertainty of
several tenths of an Angstrom. These are consistent with [OIII] 5007 emission
at the 1475 +/- 7 km/s radial velocity of the globular cluster previously
determined from an analysis of its absorption lines. This agreement within the
small uncertainties argues strongly in favor of the interpretation of the line
as [OIII] 5007 emission from the black-hole hosting globular cluster. We also
find that the emission line most likely has a velocity width of several hundred
km/s. Such a velocity width rules out a planetary nebula explanation for the
[OIII] 5007 emission and implicates the black hole as the source of the power
driving the nebular emission.


title:
Linearized force constants method for lattice dynamics in mixed
  semiconductors

abstract:
  A simple and accurate method of calculating phonon spectra in mixed
semiconductors alloys, on the basis of preliminarily (from first principles)
relaxed atomic structure, is proposed and tested for (Zn,Be)Se and (Ga,In)As
solid solutions. The method uses an observation that the interatomic force
constants, calculated ab initio for a number of microscopic configurations in
the systems cited, show a clear linear variation of the main (diagonal) values
of the interatomic force constants with the corresponding bond length. We
formulate simple rules about how to recover the individual 3x3 subblocks of the
force constants matrix in their local (bonds-related) coordinate systems and
how to transform them into a global (crystal cell-related) coordinate system.
Test calculations done for 64-atom supercells representing different
concentrations of (Zn,Be)Se and (Ga,In)As show that the phonon frequencies and
compositions of eigenvectors are faithfully reproduced in a linearized force
constants calculation, as compared to true ab initio calculations.


title:
Quasi-Particle Degrees of Freedom versus the Perfect Fluid as
  Descriptors of the Quark-Gluon Plasma

abstract:
  The hot nuclear matter created at the Relativistic Heavy Ion Collider (RHIC)
has been characterized by near-perfect fluid behavior. We demonstrate that this
stands in contradiction to the identification of QCD quasi-particles with the
thermodynamic degrees of freedom in the early (fluid) stage of heavy ion
collisions. The empirical observation of constituent quark ``$n_q$'' scaling of
elliptic flow is juxtaposed with the lack of such scaling behavior in
hydrodynamic fluid calculations followed by Cooper-Frye freeze-out to hadrons.
A ``quasi-particle transport'' time stage after viscous effects break down the
hydrodynamic fluid stage, but prior to hadronization, is proposed to reconcile
these apparent contradictions. However, without a detailed understanding of the
transitions between these stages, the ``$n_q$'' scaling is not a necessary
consequence of this prescription. Also, if the duration of this stage is too
short, it may not support well defined quasi-particles. By comparing and
contrasting the coalescence of quarks into hadrons with the similar process of
producing light nuclei from nucleons, it is shown that the observation of
``$n_{q}$'' scaling in the final state does not necessarily imply that the
constituent degrees of freedom were the relevant ones in the initial state.


title: ZZ branes from a worldsheet perspective

abstract:
  We show how non-compact space-time (ZZ branes) emerges as a limit of compact
space-time (FZZT branes) for specific ratios between the square of the boundary
cosmological constant and the bulk cosmological constant in the (2,2m - 1)
minimal model coupled to two-dimensional euclidean quantum gravity.
Furthermore, we show that the principal (r,s) ZZ brane can be viewed as the
basic (1,1) ZZ boundary state tensored with a (r,s) Cardy boundary state for a
general (p,q) minimal model coupled to two-dimensional quantum gravity. In this
sense there exists only one ZZ boundary state, the basic (1,1) boundary state.


title: Formation of Kuiper Belt Binaries

abstract:
  The discovery that a substantial fraction of Kuiper Belt objects (KBOs)
exists in binaries with wide separations and roughly equal masses, has
motivated a variety of new theories explaining their formation. Goldreich et
al. (2002) proposed two formation scenarios: In the first, a transient binary
is formed, which becomes bound with the aid of dynamical friction from the sea
of small bodies (L^2s mechanism); in the second, a binary is formed by three
body gravitational deflection (L^3 mechanism). Here, we accurately calculate
the L^2s and L^3 formation rates for sub-Hill velocities. While the L^2s
formation rate is close to previous order of magnitude estimates, the L^3
formation rate is about a factor of 4 smaller. For sub-Hill KBO velocities (v
<< v_H) the ratio of the L^3 to the L^2s formation rate is 0.05 (v/v_H)
independent of the small bodies' velocity dispersion, their surface density or
their mutual collisions. For Super-Hill velocities (v >> v_H) the L^3 mechanism
dominates over the L^2s mechanism. Binary formation via the L^3 mechanism
competes with binary destruction by passing bodies. Given sufficient time, a
statistical equilibrium abundance of binaries forms. We show that the frequency
of long-lived transient binaries drops exponentially with the system's lifetime
and that such transient binaries are not important for binary formation via the
L^3 mechanism, contrary to Lee et al. (2007). For the L^2s mechanism we find
that the typical time, transient binaries must last, to form Kuiper Belt
binaries (KBBs) for a given strength of dynamical friction, D, increases only
logarithmically with D. Longevity of transient binaries only becomes important
for very weak dynamical friction (i.e. D \lesssim 0.002) and is most likely not
crucial for KBB formation.


title: Integrable systems without the Painlev\'e property

abstract:
  We examine whether the Painlev\'e property is a necessary condition for the
integrability of nonlinear ordinary differential equations. We show that for a
large class of linearisable systems this is not the case. In the discrete
domain, we investigate whether the singularity confinement property is
satisfied for the discrete analogues of the non-Painlev\'e continuous
linearisable systems. We find that while these discrete systems are themselves
linearisable, they possess nonconfined singularities.


title:
Morphology of Fine-Particle Monolayers Deposited on Nanopatterned
  Substrates

abstract:
  We study the effect of the presence of a regular substrate pattern on the
irreversible adsorption of nanosized and colloid particles. Deposition of disks
of radius $r_0$ is considered, with the allowed regions for their center
attachment at the planar surface consisting of square cells arranged in a
square lattice pattern. We study the jammed state properties of a generalized
version of the random sequential adsorption model for different values of the
cell size, $a$, and cell-cell separation, $b$. The model shows a surprisingly
rich behavior in the space of the two dimensionless parameters $\alpha=a/2r_0$
and $\beta=b/2r_0$. Extensive Monte Carlo simulations for system sizes of
$500\times500$ square lattice unit cells were performed by utilizing an
efficient algorithm, to characterize the jammed state morphology.


title:
A tail inequality for suprema of unbounded empirical processes with
  applications to Markov chains

abstract:
  We present a tail inequality for suprema of empirical processes generated by
variables with finite $\psi_\alpha$ norms and apply it to some geometrically
ergodic Markov chains to derive similar estimates for empirical processes of
such chains, generated by bounded functions. We also obtain a bounded
difference inequality for symmetric statistics of such Markov chains.


title: Spinors for Spinning p-Branes

abstract:
  The group of the p-brane world volume preserving diffeomorphism is
considered. The infinite-dimensional spinors of this group are related, by the
nonlinear realization techniques, to the corresponding spinors of its linear
subgroup, that are constructed explicitly. An algebraic construction of the
Virasoro and Neveu-Schwarz-Ramond algebras, based on this infinite-dimensional
spinors and tensors, is demonstrated.


title: Lie point symmetries of difference equations and lattices

abstract:
  A method is presented for finding the Lie point symmetry transformations
acting simultaneously on difference equations and lattices, while leaving the
solution set of the corresponding difference scheme invariant. The method is
applied to several examples. The found symmetry groups are used to obtain
particular solutions of differential-difference equations.


title: Point Sources from a Spitzer IRAC Survey of the Galactic Center

abstract:
  We have obtained Spitzer/IRAC observations of the central 2.0 x 1.4 degrees
(~280 x 200 pc) of the Galaxy at 3.6-8.0 microns. A point source catalog of
1,065,565 objects is presented. The catalog includes magnitudes for the point
sources at 3.6, 4.5, 5.8, and 8.0 microns, as well as JHK photometry from
2MASS. The point source catalog is confusion limited with average limits of
12.4, 12.1, 11.7, and 11.2 magnitudes for [3.6], [4.5], [5.8], and [8.0],
respectively. We find that the confusion limits are spatially variable because
of stellar surface density, background surface brightness level, and extinction
variations across the survey region. The overall distribution of point source
density with Galactic latitude and longitude is essentially constant, but
structure does appear when sources of different magnitude ranges are selected.
Bright stars show a steep decreasing gradient with Galactic latitude, and a
slow decreasing gradient with Galactic longitude, with a peak at the position
of the Galactic center. From IRAC color-magnitude and color-color diagrams, we
conclude that most of the point sources in our catalog have IRAC magnitudes and
colors characteristic of red giant and AGB stars.


title: Prospects For Detecting Dark Matter With GLAST In Light Of The WMAP Haze

abstract:
  Observations by the WMAP experiment have identified an excess of microwave
emission from the center of the Milky Way. It has previously been shown that
this "WMAP Haze" could be synchrotron emission from relativistic electrons and
positrons produced in the annihilations of dark matter particles. In
particular, the intensity, spectrum and angular distribution of the WMAP Haze
is consistent with an electroweak scale dark matter particle (such as a
supersymmetric neutralino or Kaluza-Klein dark matter in models with universal
extra dimensions) annihilating with a cross section on the order of sigma
v~3x10^-26 cm^3/s and distributed with a cusped halo profile. No further exotic
astrophysical or annihilation boost factors are required. If dark matter
annihilations are in fact responsible for the observed Haze, then other
annihilation products will also be produced, including gamma rays. In this
article, we study the prospects for the GLAST satellite to detect gamma rays
from dark matter annihilations in the Galactic Center region in this scenario.
We find that by studying only the inner 0.1 degrees around the Galactic Center,
GLAST will be able to detect dark matter annihilating to heavy quarks or gauge
bosons over astrophysical backgrounds with 5sigma (3sigma) significance if they
are lighter than approximately 320-500 GeV (500-750 GeV). If the angular window
is broadened to study the dark matter halo profile's angular extension (while
simultaneously reducing the astrophysical backgrounds), WIMPs as heavy as
several TeV can be identified by GLAST with high significance. Only if the dark
matter particles annihilate mostly to electrons or muons will GLAST be unable
to identify the gamma ray spectrum associated with the WMAP Haze.


title:
Cayley cones ruled by 2-planes: desingularization and implications of
  the twistor fibration

abstract:
  Cayley cones in the octonions $\mathbb{O}$ that are ruled by oriented
2-planes are equivalent to pseudoholomorphic curves in the Grassmannian of
oriented 2-planes G(2,8). The well known twistor fibration $G(2,8) -> S^6$ is
used to prove the existence of immersed higher-genus pseudoholomorphic curves
in $\gro$. Equivalently, this produces Cayley cones whose links are
$S^1$-bundles over genus-$g$ Riemann surfaces. When the degree of an immersed
pseudoholomorphic curve is large enough, the corresponding 2-ruled Cayley cone
is the asymptotic cone of a non-conical 2-ruled Cayley 4-fold.


title: Invariants of the nilpotent and solvable triangular Lie algebras

abstract:
  Invariants of the coadjoint representation of two classes of Lie algebras are
calculated. The first class consists of the nilpotent Lie algebras $T(M)$,
isomorphic to the algebras of upper triangular $M\times M$ matrices. The Lie
algebra $T(M)$ is shown to have $[M/2]$ functionally independent invariants.
They can all be chosen to be polynomials and they are presented explicitly. The
second class consists of the solvable Lie algebras $L(M,f)$ with $T(M)$ as
their nilradical and $f$ additional linearly nilindependent elements. Some
general results on the invariants of $L(M,f)$ are given and the cases M=4 for
all $f$ and $f=1$, or $f=M-1$ for all $M$ are treated in detail.


title: Statistics of Partial Minima

abstract:
  Motivated by multi-objective optimization, we study extrema of a set of N
points independently distributed inside the d-dimensional hypercube. A point in
this set is k-dominated by another point when at least k of its coordinates are
larger, and is a k-minimum if it is not k-dominated by any other point. We
obtain statistical properties of these partial minima using exact probabilistic
methods and heuristic scaling techniques. The average number of partial minima,
A, decays algebraically with the total number of points, A ~ N^{-(d-k)/k}, when
1<=k<d. Interestingly, there are k-1 distinct scaling laws characterizing the
largest coordinates as the distribution P(y_j) of the jth largest coordinate,
y_j, decays algebraically, P(y_j) ~ (y_j)^{-alpha_j-1}, with
alpha_j=j(d-k)/(k-j) for 1<=j<=k-1. The average number of partial minima grows
logarithmically, A ~ [1/(d-1)!](ln N)^{d-1}, when k=d. The full distribution of
the number of minima is obtained in closed form in two-dimensions.


title:
Constraining white-dwarf kicks in globular clusters : II. Observational
  Significance

abstract:
  If the winds of an asymptotic-giant-branch stars are sufficiently strong are
slightly asymmetric, they can alter the star's trajectory through a globular
cluster; therefore, if these winds are asymmetric, one would expect young white
dwarfs to be less radially concentrated than either their progenitors or older
white dwarfs in globular clusters. This latter effect has recently been
observed. Additionally the young white dwarfs should have larger typical
velocities than their progenitors. After phase mixing this latter effect is
vastly diminished relative to the changes in the spatial distribution of young
white dwarfs with kicks, so it is more difficult to detect than the change in
the spatial distribution. The most powerful kinematic signature is the change
in the eccentricity of the orbits that is revealed through the distribution of
the position angles of proper motion.


title:
Spitzer Mid-Infrared Spectroscopy of 70um-Selected Distant Luminous
  Infrared Galaxies

abstract:
  We present mid-infrared spectroscopy obtained with the Spitzer Space
Telescope of a sample of 11 optically faint, infrared luminous galaxies
selected from a Spitzer MIPS 70um imaging survey of the NDWFS Bootes field.
These are the first Spitzer IRS spectra presented of distant 70um-selected
sources. All the galaxies lie at redshifts 0.3<z<1.3 and have very large
infrared luminosities of L_IR~ 0.1-17 x 10^12 solar luminosities. Seven of the
galaxies exhibit strong emission features attributed to polycyclic aromatic
hydrocarbons (PAHs). The average IRS spectrum of these sources is
characteristic of classical starburst galaxies, but with much larger infrared
luminosities. The PAH luminosities of L(7.7) ~ 0.4 - 7 x 10^11 solar
luminosities imply star formation rates of ~ 40 - 720 solar masses per year.
Four of the galaxies show deep 9.7um silicate absorption features and no
significant PAH emission features (6.2um equivalent widths < 0.03um). The large
infrared luminosities and low f70/f24 flux density ratios suggests that these
sources have AGN as the dominant origin of their large mid-infrared
luminosities, although deeply embedded but luminous starbursts cannot be ruled
out. If the absorbed sources are AGN-dominated, a significant fraction of all
far-infrared bright, optically faint sources may be dominated by AGN.


title: The flat FRW model in LQC: the self-adjointness

abstract:
  The flat FRW model coupled to the massless scalar field according to the
improved, background scale independent version of Ashtekar, Pawlowski and Singh
is considered. The core of the theory is addressed directly: the APS
construction of the quantum Hamiltonian is analyzed under the assumption that
cosmological constant $\Lambda\le 0$. We prove the essential self-adjointness
of the operator whose square-root defines the quantum Hamiltonian operator and
therefore, provide the explicit definition. If $\Lambda<0$, then the spectrum
is discrete. In the $\Lambda=0$ case, the essential and absolutely continues
spectra of the operator are derived. The latter operator is related in the
unitary way to the absolutely continuous part of the Quantum Mechanics operator
$a(-\frac{\partial^2}{\partial y^2} - \frac{b}{{\rm cosh}^2\hat{y}})$ ($a,b>0$
being some constants) plus a trace class operator.


title: Low Dimensional Embedding of fMRI datasets

abstract:
  We propose a novel method to embed a functional magnetic resonance imaging
(fMRI) dataset in a low-dimensional space. The embedding optimally preserves
the local functional coupling between fMRI time series and provides a
low-dimensional coordinate system for detecting activated voxels. To compute
the embedding, we build a graph of functionally connected voxels. We use the
commute time, instead of the geodesic distance, to measure functional distances
on the graph. Because the commute time can be computed directly from the
eigenvectors of (a symmetric version) the graph probability transition matrix,
we use these eigenvectors to embed the dataset in low dimensions. After
clustering the datasets in low dimensions, coherent structures emerge that can
be easily interpreted. We performed an extensive evaluation of our method
comparing it to linear and nonlinear techniques using synthetic datasets and in
vivo datasets. We analyzed datasets from the EBC competition obtained with
subjects interacting in an urban virtual reality environment. Our exploratory
approach is able to detect independently visual areas (V1/V2, V5/MT), auditory
areas, and language areas. Our method can be used to analyze fMRI collected
during ``natural stimuli''.


title: Normes invariantes et existence de filtrations admissibles

abstract:
  Let L be a finite extension of Q_p and d a positive integer. A conjecture,
due to C. Breuil and P. Schneider, says that the existence of invariant norms
on certain locally algebraic representations of GL_{d+1}(L) should be
equivalent to the existence of certain (d+1)-dimensional de Rham
representations of Gal(\bar{L}/L). We prove the easy direction of this
conjecture: the existence of invariant norms implies the existence of
admissible filtrations, by generalizing an idea of M.Emerton.


title:
A general existence proof for non-linear elliptic equations in
  semi-Riemannian spaces

abstract:
  We present a general existence proof for a wide class of non-linear elliptic
equations which can be applied to problems with barrier conditions without
specifying any assumptions guaranteeing the uniqueness or local uniqueness of
particular solutions.
  As an application we prove the existence of closed hypersurfaces with
curvature prescribed in the tangent bundle of an ambient Riemannian manifold
$N$ without supposing any sign condition on the sectional curvatures $K_N$. A
curvature flow wouldn't work in this situation, neither the method of
successive approximation.


title:
Combinatorial Entropy for Distinguishable Entities in Indistinguishable
  States

abstract:
  The combinatorial basis of entropy by Boltzmann can be written $H= {N}^{-1}
\ln \mathbb{W}$, where $H$ is the dimensionless entropy of a system, per unit
entity, $N$ is the number of entities and $\mathbb{W}$ is the number of ways in
which a given realization of the system can occur, known as its statistical
weight. Maximizing the entropy (``MaxEnt'') of a system, subject to its
constraints, is then equivalent to choosing its most probable (``MaxProb'')
realization. For a system of distinguishable entities and states, $\mathbb{W}$
is given by the multinomial weight, and $H$ asymptotically approaches the
Shannon entropy. In general, however, $\mathbb{W}$ need not be multinomial,
leading to different entropy measures. This work examines the allocation of
distinguishable entities to non-degenerate or equally degenerate,
indistinguishable states. The non-degenerate form converges to the Shannon
entropy in some circumstances, whilst the degenerate case gives a new entropy
measure, a function of a multinomial coefficient, coding parameters, and
Stirling numbers of the second kind.


title: Energy Dependent Morphology in the PWN candidate HESS J1825-137

abstract:
  Observations with H.E.S.S. revealed a new source of very high-energy (VHE)
gamma-rays above 100 GeV - HESS J1825-137 - extending mainly to the south of
the energetic pulsar PSR B1823-13. A detailed spectral and morphological
analysis of HESS J1825-137 reveals for the first time in VHE gamma-ray
astronomy a steepening of the energy spectrum with increasing distance from the
pulsar. This behaviour can be understood by invoking radiative cooling of the
IC-Compton gamma-ray emitting electrons during their propagation. In this
scenario the vastly different sizes between the VHE gamma-ray emitting region
and the X-ray PWN associated with PSR B1823-13 can be naturally explained by
different cooling timescales for the radiating electron populations. If this
scenario is correct, HESS J1825-137 can serve as a prototype for a whole class
of asymmetric PWN in which the X-rays are extended over a much smaller angular
scales than the gamma-rays and can help understanding recent detections of
X-ray PWN in systems such as HESS J1640-465 and HESS J1813-178. The future
GLAST satellite will probe lower electron energies shedding further light on
cooling and diffusion processes in this source.


title: Induced forests in regular graphs with large girth

abstract:
  An induced forest of a graph G is an acyclic induced subgraph of G. The
present paper is devoted to the analysis of a simple randomised algorithm that
grows an induced forest in a regular graph. The expected size of the forest it
outputs provides a lower bound on the maximum number of vertices in an induced
forest of G. When the girth is large and the degree is at least 4, our bound
coincides with the best bound known to hold asymptotically almost surely for
random regular graphs. This results in an alternative proof for the random
case.


title: Future GLAST observations of Supernova remnants and Pulsar Wind Nebulae

abstract:
  Shell-type Supernova remnants (SNRs) have long been known to harbour a
population of ultra-relativistic particles, accelerated in the Supernova shock
wave by the mechanism of diffusive shock acceleration. Experimental evidence
for the existence of electrons up to energies of ~100 TeV was first provided by
the detection of hard X-ray synchrotron emission as e.g. in the shell of the
young SNR SN1006. Furthermore using theoretical arguments shell-type Supernova
remnants have long been considered as the main accelerator of protons - Cosmic
rays - in the Galaxy; definite proof of this process is however still missing.
Pulsar Wind Nebulae (PWN) - diffuse structures surrounding young pulsars - are
another class of objects known to be a site of particle acceleration in the
Galaxy, again through the detection of hard synchrotron X-rays such as in the
Crab Nebula. Gamma-rays above 100 MeV provide a direct access to acceleration
processes. The GLAST Large Area telescope (LAT) will be operating in the energy
range between 30 MeV and 300 GeV and will provide excellent sensitivity,
angular and energy resolution in a previously rather poorly explored energy
band. We will describe prospects for the investigation of these Galactic
particle accelerators with GLAST.


title: A Note on an Asymptotically Good Tame Tower

abstract:
  The explicit construction of function fields tower with many rational points
relative to the genus in the tower play a key role for the construction of
asymptotically good algebraic-geometric codes. In 1997 Garcia, Stichtenoth and
Thomas [6] exhibited two recursive asymptotically good Kummer towers over any
non-prime field. Wulftange determined the limit of one tower in his PhD thesis
[13]. In this paper we determine the limit of another tower [14].


title:
Photon pair-state preparation with tailored spectral properties by
  spontaneous four-wave mixing in photonic-crystal fiber

abstract:
  We study theoretically the generation of photon pairs by spontaneous
four-wave mixing (SFWM) in photonic crystal optical fiber. We show that it is
possible to engineer two-photon states with specific spectral correlation
(``entanglement'') properties suitable for quantum information processing
applications. We focus on the case exhibiting no spectral correlations in the
two-photon component of the state, which we call factorability, and which
allows heralding of single-photon pure-state wave packets without the need for
spectral post filtering. We show that spontaneous four wave mixing exhibits a
remarkable flexibility, permitting a wider class of two-photon states,
including ultra-broadband, highly-anticorrelated states.


title: Twisting Elements in Homotopy G-algebras

abstract:
  We study the notion of twisting elements $da=a\cup_1a$ with respect to
$\cup_1$ product when it is a part of homotopy Gerstenhaber algebra structure.
This allows to bring to one context the two classical concepts, the theory of
deformation of algebras of M. Gerstenhaber, and $A(\infty)$-algebras of J.
Stasheff.


title: Does a Computer have an Arrow of Time?

abstract:
  In [Sch05a], it is argued that Boltzmann's intuition, that the psychological
arrow of time is necessarily aligned with the thermodynamic arrow, is correct.
Schulman gives an explicit physical mechanism for this connection, based on the
brain being representable as a computer, together with certain thermodynamic
properties of computational processes. [Haw94] presents similar, if briefer,
arguments. The purpose of this paper is to critically examine the support for
the link between thermodynamics and an arrow of time for computers. The
principal arguments put forward by Schulman and Hawking will be shown to fail.
It will be shown that any computational process that can take place in an
entropy increasing universe, can equally take place in an entropy decreasing
universe. This conclusion does not automatically imply a psychological arrow
can run counter to the thermodynamic arrow. Some alternative possible explana-
tions for the alignment of the two arrows will be briefly discussed.


title:
The Giant Monopole Resonance in the $^{112-124}$Sn Isotopes and the
  Symmetry Energy Term in Nuclear Incompressibility

abstract:
  We have investigated the isoscalar giant monopole resonance (GMR) in the Sn
isotopes, using inelastic scattering of 400-MeV $\alpha$-particles at extremely
forward angles, including 0 deg. A value of -550 \pm 100 MeV has been obtained
for the asymmetry term, $K_\tau$, in the nuclear incompressibility.


title: The Renormalized Tensor Interaction in a Nucleus

abstract:
  We show several examples were the tensor interaction of the lowest order G
matrix in a nucleus is too strong. The examples include the quadrupole moment
of $^{6}$Li, the isosplitting of the lowest 0$^{-}$ states in $^{16}$O, the
near vanishing Gamow-Teller matrix element in the weak decay of the J=0 T=1
state of $^{14}$O to the J=1 T=0 ground state of $^{14}$N, and the magnitude of
the deformation of $^{12}$C. It would appear that we could get better results
by decreasing the tensor interaction strength by about a factor of two. We then
examine the simple estimates of Gerry Brown concerning second order tensor
effects. We note that for the triplet even channel the combination of first and
second order tensor does indeed yield an effective weaker tensor interaction
and helps to get better agreement with experiment.


title: Edge Effects in Finite Elongated Graphene Nanoribbons

abstract:
  We analyze the relevance of finite-size effects to the electronic structure
of long graphene nanoribbons using a divide and conquer density functional
approach. We find that for hydrogen terminated graphene nanoribbons most of the
physical features appearing in the density of states of an infinite graphene
nanoribbon are recovered at a length of 40 nm. Nevertheless, even for the
longest systems considered (72 nm long) pronounced edge effects appear in the
vicinity of the Fermi energy. The weight of these edge states scales inversely
with the length of the ribbon and they are expected to become negligible only
at ribbons lengths of the order of micrometers. Our results indicate that
careful consideration of finite-size and edge effects should be applied when
designing new nanoelectronic devices based on graphene nanoribbons. These
conclusions are expected to hold for other one-dimensional systems such as
carbon nanotubes, conducting polymers, and DNA molecules.


title: A Kondo lattice antiferromagnet CePd5Al2

abstract:
  We report on the electrical resistivity, magnetic susceptibility and
heat-capacity measurements on a new intermetallic compound CePd5Al2,
crystallizing in the ZrNi2Al5-type tetragonal structure, with lattice
parameters a = 4.156 A and c = 14.883 A. The compound presents Kondo lattice
behavior and an easy-plane antiferromagnetic ground state with two magnetic
transitions at 2.9 K and 3.9 K. The Sommerfeld coefficient is estimated as 60
mJ/mol K^2.


title: Bulk scalar field in DGP braneworld cosmology

abstract:
  We investigated the effects of bulk scalar field in the braneworld
cosmological scenario. The Friedmann equations and acceleration condition in
presence of the bulk scalar field for a zero tension brane and cosmological
constant are studied. In DGP model the effective Einstein equation on the brane
is obtained with bulk scalar field. The rescaled bulk scalar field on the brane
in the DGP model behaves as an effective four dimensional field, thus standard
type cosmology is recovered. In present study of the DGP model, the late-time
accelerating phase of the universe can be explained .


title: Observation of photon-assisted tunneling in optical lattices

abstract:
  We have observed tunneling suppression and photon-assisted tunneling of
Bose-Einstein condensates in an optical lattice subjected to a constant force
plus a sinusoidal shaking. For a sufficiently large constant force, the ground
energy levels of the lattice are shifted out of resonance and tunneling is
suppressed; when the shaking is switched on, the levels are coupled by
low-frequency photons and tunneling resumes. Our results agree well with
theoretical predictions and demonstrate the usefulness of optical lattices for
studying solid-state phenomena.


title: A comment on Ryser's conjecture for intersecting hypergraphs

abstract:
  Let $\tau(\mathcal{H})$ be the cover number and $\nu(\mathcal{H})$ be the
matching number of a hypergraph $\mathcal{H}$. Ryser conjectured that every
$r$-partite hypergraph $\mathcal{H}$ satisfies the inequality
$\tau(\mathcal{H}) \leq (r-1) \nu (\mathcal{H})$. This conjecture is open for
all $r \ge 4$. For intersecting hypergraphs, namely those with
$\nu(\mathcal{H})=1$, Ryser's conjecture reduces to $\tau(\mathcal{H}) \leq
r-1$. Even this conjecture is extremely difficult and is open for all $ r \ge
6$. For infinitely many $r$ there are examples of intersecting $r$-partite
hypergraphs with $\tau(\mathcal{H})=r-1$, demonstrating the tightness of the
conjecture for such $r$. However, all previously known constructions are not
optimal as they use far too many edges. How sparse can an intersecting
$r$-partite hypergraph be, given that its cover number is as large as possible,
namely $\tau(\mathcal{H}) \ge r-1$? In this paper we solve this question for $r
\le 5$, give an almost optimal construction for $r=6$, prove that any
$r$-partite intersecting hypergraph with $\tau(H) \ge r-1$ must have at least
$(3-\frac{1}{\sqrt{18}})r(1-o(1)) \approx 2.764r(1-o(1))$ edges, and conjecture
that there exist constructions with $\Theta(r)$ edges.


title: Plane Symmetric Gravitational Collapse

abstract:
  In this paper, we derive the general formulation by considering two arbitrary
plane symmetric spacetimes using Israel's method. As an example, we apply this
formulation to known plane symmetric spacetimes. We take the Taub's static
metric in the interior region whereas Kasner's non-static metric in the
exterior region. It is shown that the plane collapses in some cases whereas it
expands in some other cases.


title: Some Relations between Rank, Chromatic Number and Energy of Graphs

abstract:
  The energy of a graph $G$, denoted by $E(G)$, is defined as the sum of the
absolute values of all eigenvalues of $G$. Let $G$ be a graph of order $n$ and
${\rm rank}(G)$ be the rank of the adjacency matrix of $G$. In this paper we
characterize all graphs with $E(G)={\rm rank}(G)$. Among other results we show
that apart from a few families of graphs, $E(G)\geq 2\max(\chi(G),
n-\chi(\bar{G}))$, where $n$ is the number of vertices of $G$, $\bar{G}$ and
$\chi(G)$ are the complement and the chromatic number of $G$, respectively.
Moreover some new lower bounds for $E(G)$ in terms of ${\rm rank}(G)$ are
given.


title:
Local and Global relations between the number of contacts and density in
  monodisperse sphere packs

abstract:
  The topological structure resulting from the network of contacts between
grains (\emph{contact network}) is studied for large samples of monosized
spheres with densities (fraction of volume occupied by the spheres) ranging
from 0.59 to 0.64. We retrieve the coordinates of each bead in the pack and we
calculate the average coordination number by using three different methods. We
show that, in the range of density investigated, the coordination number is
larger than 4 and it increases with the packing fraction. At local level we
also observe a positive correlation between local packing fraction and number
of neighbors. We discover a dependence between the local densities of
configurations with few neighbors in contact and the global sample-denities.
This might indicate that local configurations with small number of neighbors
are able to deform plastically when the sample is compactifying.
  PACS: 45.70.-n, Granular Systems; 45.70.Cc, Static sandpiles; Granular
Compaction.


title:
Aharonov-Bohm-like effect for light propagating in nematics with
  disclinations

abstract:
  Using a geometric approach for the propagation of light in anisotropic media,
we investigate what effect the director field of disclinations may have on the
polarization state of light. Parallel transport around the defect, of the
spinor describing the polarization, indicates the acquisition of a topological
phase, in analogy with the Aharonov-Bohm effect.


title: Lyapunov Mode Dynamics in Hard-Disk Systems

abstract:
  The tangent dynamics of the Lyapunov modes and their dynamics as generated
numerically - {\it the numerical dynamics} - is considered. We present a new
phenomenological description of the numerical dynamical structure that
accurately reproduces the experimental data for the quasi-one-dimensional
hard-disk system, and shows that the Lyapunov mode numerical dynamics is linear
and separate from the rest of the tangent space. Moreover, we propose a new,
detailed structure for the Lyapunov mode tangent dynamics, which implies that
the Lyapunov modes have well-defined (in)stability in either direction of time.
We test this tangent dynamics and its derivative properties numerically with
partial success. The phenomenological description involves a time-modal linear
combination of all other Lyapunov modes on the same polarization branch and our
proposed Lyapunov mode tangent dynamics is based upon the form of the tangent
dynamics for the zero modes.


title: Inclusion Matrices and Chains

abstract:
  Given integers $t$, $k$, and $v$ such that $0\leq t\leq k\leq v$, let
$W_{tk}(v)$ be the inclusion matrix of $t$-subsets vs. $k$-subsets of a
$v$-set. We modify slightly the concept of standard tableau to study the notion
of rank of a finite set of positive integers which was introduced by Frankl.
Utilizing this, a decomposition of the poset $2^{[v]}$ into symmetric skipless
chains is given. Based on this decomposition, we construct an inclusion matrix,
denoted by $W_{\bar{t}k}(v)$, which is row-equivalent to $W_{tk}(v)$. Its Smith
normal form is determined. As applications, Wilson's diagonal form of
$W_{tk}(v)$ is obtained as well as a new proof of the well known theorem on the
necessary and sufficient conditions for existence of integral solutions of the
system $W_{tk}\bf{x}=\bf{b}$ due to Wilson. Finally we present anotherinclusion
matrix with similar properties to those of $W_{\bar{t}k}(v)$ which is in some
way equivalent to $W_{tk}(v)$.


title:
On the properties of generalized harmonic and oscillatory numbers.
  Simple proof of the Prime Number Theorem

abstract:
  We derived the sum identities for generalized harmonic and corresponding
oscillatory numbers for which a sieve procedure can be applied. The obtained
results enable us to understand better the properties of these numbers and
their asymptotic behavior. On the basis of these identities a simple proof of
the Prime Number Theorem is represented.


title:
Roughness corrections to the Casimir force: The importance of local
  surface slope

abstract:
  This paper concentrates on a study where finite conductivity corrections are
included in the theoretical description of the effects of roughness on the
Casimir force. The roughness data were taken from gold films evaporated onto
Silicon and polysterene spheres. We conclude that for a detailed comparison
with experimental data, i.e. at the level of at least 5 % at short separations
below 200 nm, the lateral dimensions of roughness for real films should be
included in the theoretical considerations. Moreover, if the RMS roughness is
considerable, high local surface slopes are shown to have a significant effect
on the Casimir force.


title:
A Handy Tool for History Keeping of Geant4 Tracks and its Application to
  Studies of Fundamental Limits on PFA Performance

abstract:
  It is widely recognized that good jet energy resolution is one of the most
important requirements to the detectors for the future linear $e^+e^-$ collider
experiments. The Particle Flow Analysis (PFA) is currently under intense
studies as the most promising way to achieving the best attainable resolution.
In order to clarify the fundamental limits on the jet energy resolution with
the PFA, we have developed a set of C++ classes that facilitates history
keeping of particle tracks within the framework of Geant4. In this paper this
software tool is described and applied to a generic detector model so as to
identify fundamental limiting factors to the PFA performance.


title: Latest results on b-hadron spectroscopy from CDF

abstract:
  B-hadron spectroscopy presents an interesting window for the study of QCD.
CDF has performed a number of studies involving the production and spectroscopy
of B mesons. Among these studies are the first direct observation of the Bc,
and the first observation of both narrow states of the Bs**. In addition,
measurements are made of the B** masses and widths and the best limit on the
production of Eta_b is set.


title:
Local cohomology based on a nonclosed support defined by a pair of
  ideals

abstract:
  We introduce an idea for generalization of a local cohomology module, which
we call a local cohomology module with respect to a pair of ideals (I,J), and
study their various properties. Some vanishing and nonvanishing theorems are
given for this generalized version of local cohomology. We also discuss its
connection with the ordinary local cohomology.


title: Nucleon form factors from quenched lattice QCD with domain wall fermions

abstract:
  We present a quenched lattice calculation of the weak nucleon form factors:
vector (F_V(q^2)), induced tensor (F_T(q^2)), axial-vector (F_A(q^2)) and
induced pseudo-scalar (F_P(q^2)) form factors. Our simulations are performed on
three different lattice sizes L^3 x T=24^3 x 32, 16^3 x 32 and 12^3 x 32 with a
lattice cutoff of 1/a = 1.3 GeV and light quark masses down to about 1/4 the
strange quark mass (m_{pi} = 390 MeV) using a combination of the DBW2 gauge
action and domain wall fermions. The physical volume of our largest lattice is
about (3.6 fm)^3, where the finite volume effects on form factors become
negligible and the lower momentum transfers (q^2 = 0.1 GeV^2) are accessible.
The q^2-dependences of form factors in the low q^2 region are examined. It is
found that the vector, induced tensor, axial-vector form factors are well
described by the dipole form, while the induced pseudo-scalar form factor is
consistent with pion-pole dominance. We obtain the ratio of axial to vector
coupling g_A/g_V=F_A(0)/F_V(0)=1.219(38) and the pseudo-scalar coupling
g_P=m_{mu}F_P(0.88m_{mu}^2)=8.15(54), where the errors are statistical erros
only. These values agree with experimental values from neutron beta decay and
muon capture on the proton. However, the root mean squared radii of the vector,
induced tensor and axial-vector underestimate the known experimental values by
about 20%. We also calculate the pseudo-scalar nucleon matrix element in order
to verify the axial Ward-Takahashi identity in terms of the nucleon matrix
elements, which may be called as the generalized Goldberger-Treiman relation.


title: Suzaku Observation of the RCW86 Northeastern Shell

abstract:
  This paper reports the Suzaku results on the northeast shell of RCW 86. With
the spatial and spectral analysis, we separated the X-rays into three distinct
components; low (kT_e~0.3keV) and high (kT_e~1.8keV) temperature plasmas and a
non-thermal component, and discovered their spatial distributions are different
from each other. The low temperature plasma is dominated at the east rim,
whereas the non-thermal emission is the brightest at the northeast rim which is
spatially connected from the east rim. The high temperature plasma, found to
contain the ~6.42keV line (K alpha of low-ionized iron), is enhanced at the
inward region with respect to the east rim and has no spatial correlation with
the non-thermal X-ray (the northeast). The Fe-Kalpha line, therefore, is not
related to the non-thermal emission but originates from Fe-rich ejecta heated
to the high temperatures by the reverse shock. Since the metal abundances of
the low temperature plasma are sub-solar, the most possible origin of this
component is interstellar medium heated by a blast wave. The non-thermal X-ray,
which has a power-law index of ~2.8, is likely to be synchrotron emission. A
possible scenario to explain these morphologies and spectra is: A fast moving
blast wave in a thin cavity of OB association collided with a dense
interstellar medium or cloud at the east region very recently. As the result,
the reverse shock in this interior decelerated, and arrived at the Fe-rich
region of the ejecta and heated it. In the northeast rim, on the other hand,
the blast wave is still moving fast, and accelerated high energy electrons to
emit synchrotron X-rays.


title: Is the shell-focusing singularity of Szekeres space-time visible?

abstract:
  The visibility of the shell-focusing singularity in Szekeres space-time -
which represents quasi-spherical dust collapse - has been studied on numerous
occasions in the context of the cosmic censorship conjecture. The various
results derived have assumed that there exist radial null geodesics in the
space-time. We show that such geodesics do not exist in general, and so
previous results on the visibility of the singularity are not generally valid.
More precisely, we show that the existence of a radial geodesic in Szekeres
space-time implies that the space-time is axially symmetric, with the geodesic
along the polar direction (i.e. along the axis of symmetry). If there is a
second non-parallel radial geodesic, then the space-time is spherically
symmetric, and so is a Lema\^{\i}tre-Tolman-Bondi (LTB) space-time. For the
case of the polar geodesic in an axially symmetric Szekeres space-time, we give
conditions on the free functions (i.e. initial data) of the space-time which
lead to visibility of the singularity along this direction. Likewise, we give a
sufficient condition for censorship of the singularity. We point out the
complications involved in addressing the question of visibility of the
singularity both for non-radial null geodesics in the axially symmetric case
and in the general (non-axially symmetric) case, and suggest a possible
approach.


title:
Morse-Novikov theory, Heegaard splittings and closed orbits of gradient
  flows

abstract:
  The works of Donaldson and Mark make the structure of the Seiberg-Witten
invariant of 3-manifolds clear. It corresponds to certain torsion type
invariants counting flow lines and closed orbits of a gradient flow of a
circle-valued Morse map on a 3-manifold. We study these invariants using the
Morse-Novikov theory and Heegaard splitting for sutured manifolds, and make
detailed computations for knot complements.


title: A Bayesian analysis of pentaquark signals from CLAS data

abstract:
  We examine the results of two measurements by the CLAS collaboration, one of
which claimed evidence for a $\Theta^{+}$ pentaquark, whilst the other found no
such evidence. The unique feature of these two experiments was that they were
performed with the same experimental setup. Using a Bayesian analysis we find
that the results of the two experiments are in fact compatible with each other,
but that the first measurement did not contain sufficient information to
determine unambiguously the existence of a $\Theta^{+}$. Further, we suggest a
means by which the existence of a new candidate particle can be tested in a
rigorous manner.


title:
Restriction of stable bundles on a jacobian of genus 2 to an embedded
  curve

abstract:
  The aim of this note is to describe the restriction map from the moduli space
of stable rank 2 bundle with small $c_2$ on a jacobian $X$ of dimension 2, to
the moduli space of stable rank 2 bundles on the corresponding genus 2 curve
$C$ embedded in $X$.


title:
Two distinct logical types of network control in gene expression
  profiles

abstract:
  In unicellular organisms such as bacteria the same acquired mutations
beneficial in one environment can be restrictive in another. However, evolving
Escherichia coli populations demonstrate remarkable flexibility in adaptation.
The mechanisms sustaining genetic flexibility remain unclear. In E. coli the
transcriptional regulation of gene expression involves both dedicated
regulators binding specific DNA sites with high affinity and also global
regulators - abundant DNA architectural proteins of the bacterial chromoid
binding multiple low affinity sites and thus modulating the superhelical
density of DNA. The first form of transcriptional regulation is dominantly
pairwise and specific, representing digitial control, while the second form is
(in strength and distribution) continuous, representing analog control. Here we
look at the properties of effective networks derived from significant gene
expression changes under variation of the two forms of control and find that
upon limitations of one type of control (caused e.g. by mutation of a global
DNA architectural factor) the other type can compensate for compromised
regulation. Mutations of global regulators significantly enhance the digital
control; in the presence of global DNA architectural proteins regulation is
mostly of the analog type, coupling spatially neighboring genomic loci;
together our data suggest that two logically distinct types of control are
balancing each other. By revealing two distinct logical types of control, our
approach provides basic insights into both the organizational principles of
transcriptional regulation and the mechanisms buffering genetic flexibility. We
anticipate that the general concept of distinguishing logical types of control
will apply to many complex biological networks.


title: Chiral Lagrangians with tensor sources

abstract:
  The implementation of tensor sources in Chiral Lagrangians allows the
computation of Green functions and form factors involving tensor currents, that
is, quark bilinears of the form \bar{q}_i\sigma^{\mu\nu}q_j. Whereas only four
new terms show up at O(p^4), we find around a hundred of them at O(p^6). So it
becomes essential to ensure that this set o operators is indeed minimal and
non-redundant (i.e., it is a basis). We discuss two phenomenological
applications in the context of vector meson resonances and the radiative pion
decay.


title: Twin peaks in rf spectra of Fermi gases at unitarity

abstract:
  We calculate the radio-frequency spectrum of balanced and imbalanced
ultracold Fermi gases in the normal phase at unitarity.
  For the homogeneous case the spectrum of both the majority and minority
components always has a single peak even in the pseudogap regime.
  We furthermore show how the double-peak structures observed in recent
experiments arise due to the inhomogeneity of the trapped gas.
  The main experimental features observed above the critical temperature in the
recent experiment of Schunck et al. [Science 316, 867, (2007)] are recovered
with no fitting parameters.


title: The Energy-momentum of a Poisson structure

abstract:
  Consider the quasi-commutative approximation to a noncommutative geometry. It
is shown that there is a natural map from the resulting Poisson structure to
the Riemann curvature of a metric. This map is applied to the study of
high-frequency gravitational radiation. In classical gravity in the WKB
approximation there are two results of interest, a dispersion relation and a
conservation law. Both of these results can be extended to the noncommutative
case, with the difference that they result from a cocycle condition on the
high-frequency contribution to the Poisson structure, not from the field
equations.


title:
An Efficient and Simple Analytical Model for Analysis of Propagation
  Properties in Impedance Waveguides

abstract:
  In this paper propagation properties of a parallel-plate waveguide with
tunable artificial impedance surfaces as sidewalls are studied both
analytically and numerically. The impedance surfaces comprise an array of
patches over a dielectric slab with embedded metallic vias. The tunability of
surfaces is achieved with varactors. Simple design equations for tunable
artificial impedance surfaces as well as dispersion equations for the TE and TM
modes are presented. The propagation properties are studied in three different
regimes: a multi-mode waveguide, a single-mode waveguide, and below-cutoff
waveguide. The analytical results are verified with numerical simulations.


title: Rosen-Zener Transition in a Nonlinear Two-Level System

abstract:
  We study Rosen-Zener transition (RZT) in a nonlinear two-level system in
which the level energies depend on the occupation of the levels, representing a
mean-field type of interaction between the particles. We find that the
nonlinearity could affect the quantum transition dramatically. At certain
nonlinearity the 100% population transfer between two levels is observed and
found to be robust over a very wide range of external parameters. On the other
hand, the quantum transition could be completely blocked by a strong
nonlinearity. In the sudden and adiabatic limits we have derived analytical
expressions for the transition probability. Numerical explorations are made for
a wide range of parameters of the general case. Possible applications of our
theory to Bose-Einstern Condensates (BECs) are discussed.


title: Some new class of Chaplygin Wormholes

abstract:
  Some new class of Chaplygin wormholes are investigated in the framework of a
Chaplygin gas with equation of state $ p = - \frac{A}{\rho}$, $A>0$. Since
empty spacetime ($ p = \rho = 0 $) does not follow Chaplygin gas, so the
interior Chaplygin wormhole solutions will never asymptotically flat. For this
reason, we have to match our interior wormhole solution with an exterior vacuum
solution i.e. Schwarzschild solution at some junction interface, say $ r = a $.
We also discuss the total amount of matter characterized by Chaplygin gas that
supplies fuel to construct a wormhole.


title:
Few-boson dynamics in double wells: From single-atom to correlated-pair
  tunneling

abstract:
  We investigate few-boson tunneling in a one-dimensional double well, covering
the full crossover from weak interactions to the fermionization limit of strong
correlations. Based on exact quantum-dynamical calculations, it is found that
the tunneling dynamics of two atoms evolves from Rabi oscillations to
correlated pair tunneling as we increase the interaction strength. Near the
fermionization limit, fragmented-pair tunneling is observed and analyzed in
terms of the population imbalance and two-body correlations. For more atoms,
the tunneling dynamics near fermionization is shown to be sensitive to both
atom number and initial configuration.


title:
Transport through constricted quantum Hall edge systems: beyond the
  quantum point contact

abstract:
  Motivated by surprises in recent experimental findings, we study transport in
a model of a quantum Hall edge system with a gate-voltage controlled
constriction. A finite backscattered current at finite edge-bias is explained
from a Landauer-Buttiker analysis as arising from the splitting of edge current
caused by the difference in the filling fractions of the bulk ($\nu_{1}$) and
constriction ($\nu_{2}$) quantum Hall fluid regions. We develop a hydrodynamic
theory for bosonic edge modes inspired by this model. The constriction region
splits the incident long-wavelength chiral edge density-wave excitations among
the transmitting and reflecting edge states encircling it. The competition
between two interedge tunneling processes taking place inside the constriction,
related by a quasiparticle-quasihole (qp-qh) symmetry, is accounted for by
computing the boundary theories of the system. This competition is found to
determine the strong coupling configuration of the system. A separatrix of
qp-qh symmetric gapless critical states is found to lie between the relevant RG
flows to a metallic and an insulating configuration of the constriction system.
This constitutes an interesting generalisation of the Kane-Fisher quantum
impurity model. The features of the RG phase diagram are also confirmed by
computing various correlators and chiral linear conductances of the system. In
this way, our results find excellent agreement with many recent puzzling
experimental results for the cases of $\nu_{1}=1/3,~1$. We also discuss and
make predictions for the case of a constriction system with $\nu_{2}=5/2$.


title:
Level sets of the stochastic wave equation driven by a symmetric
  L\'{e}vy noise

abstract:
  We consider the solution $\{u(t,x);t\geq0,x\in\mathbf{R}\}$ of a system of
$d$ linear stochastic wave equations driven by a $d$-dimensional symmetric
space-time L\'{e}vy noise. We provide a necessary and sufficient condition on
the characteristic exponent of the L\'{e}vy noise, which describes exactly when
the zero set of $u$ is non-void. We also compute the Hausdorff dimension of
that zero set when it is non-empty. These results will follow from more general
potential-theoretic theorems on the level sets of L\'{e}vy sheets.


title: N=2 Quiver Gauge Model and Partial Supersymmetry Breaking

abstract:
  We construct an action of N=2 affine $A_n$ quiver gauge model having
non-canonical kinetic terms and equipped with electric and magnetic FI terms.
N=2 supersymmetry is shown to be broken to N=1 spontaneously and N=1 multiplets
realized on the vacua are given. We also mention the models with different
gauge groups. It is argued that the affine $A_1$ quiver gauge model provides a
dynamical realization to approach the Klebanov-Witten N=1 fixed point.


title:
Giant Resonances using Correlated Realistic Interactions: The Case for
  Second RPA

abstract:
  Lately we have been tackling the problem of describing nuclear collective
excitations starting from correlated realistic nucleon-nucleon (NN)
interactions. The latter are constructed within the Unitary Correlation
Operator Method (UCOM), starting from realistic NN potentials. It has been
concluded that first-order RPA with a two-body UCOM interaction is not capable,
in general, of reproducing quantitatively the properties of giant resonances
(GRs), due to missing higher-order configurations and long-range correlations
as well as neglected three-body terms in the Hamiltonian.
  Here we report results on GRs obtained by employing a UCOM interaction based
on the Argonne V18 potential in Second RPA (SRPA) calculations. The same
interaction is used to describe the Hartree-Fock (HF) ground state and the
residual interactions. We find that the inclusion of second-order
configurations -- which effectively dress the underlying HF single-particle
states with self-energy insertions -- produces sizable corrections. The effect
appears essential for a realistic description of GRs when using the UCOM. We
argue that effects of higher than second order should be negligible. Therefore,
the UCOM-SRPA emerges as a promising tool for consistent calculations of
collective states in closed-shell nuclei. This is an interesting development,
given that SRPA can accommodate more physics than RPA (e.g., fragmentation).
Remaining discrepancies due to the missing three-body terms and
self-consistency issues of the present SRPA model are pointed out.


title: XMM-Newton observation of the cluster ZW 1305.4+2941 in the field SA 57

abstract:
  We report the details of an XMM observation of the cluster of galaxies ZW
1305.4+2941 at the intermediate redshift of z=0.241, increasing the small
number of interesting X-ray constraints on properties of ~3 keV systems above
z=0.1. Based on the 45 ks XMM observation, we find that within a radius of 228
kpc the cluster has an unabsorbed X-ray flux of 2.07 +/- 0.06 x 10^{-13}
erg/cm^2/s, a temperature of kT = 3.17 +/-0.19 keV, in good agreement with the
previous ROSAT determination, and an abundance of 0.93 (+0.24,-0.29} solar.
Within r_500 = 723 +/- 6 kpc the rest-frame bolometric X-ray luminosity is L_X
(r_500)= 1.25 +/- 0.16 x 10^{44} erg/s. The cluster obeys the scaling relations
for L_X, T and the velocity dispersion derived at intermediate redshift for kT
< 4 keV, for which we provide new fits for all literature objects. The mass
derived from an isothermal NFW model fit is, M_vir = 2.77 +/- 0.21 x 10^{14}
solar masses, with a concentration parameter, c = 7.9 +/- 0.5.


title: Singular extensions and triangulated categories

abstract:
  We propose a new look on triangulated categories, which is based on the
second Hochschild cohomology.


title:
Non-commutative Real Algebraic Geometry - Some Basic Concepts and First
  Ideas

abstract:
  We propose and discuss how basic notions (quadratic modules, positive
elements, semialgebraic sets, Archimedean orderings) and results
(Positivstellensaetze) from real algebraic geometry can be generalized to
noncommutative $*$-algebras. A version of Stengle's Positivstellensatz for $n
\times n$ matrices of real polynomials is proved.


title:
Shear thickening of cornstarch suspensions as a re-entrant jamming
  transition

abstract:
  We study the rheology of cornstarch suspensions, a dense system of
non-Brownian particles that exhibits shear thickening, i.e. a viscosity that
increases with increasing shear rate. Using MRI velocimetry we show that the
suspension has a yield stress. From classical rheology it follows that as a
function of the applied stress the suspension is first solid (yield stress),
then liquid and then solid again when it shear thickens. The onset shear rate
for thickening is found to depend on the measurement geometry: the smaller the
gap of the shear cell, the lower the shear rate at which thickening occurs.
Shear thickening can then be interpreted as the consequence of the Reynolds
dilatancy: the system under flow wants to dilate but instead undergoes a
jamming transition because it is confined, as confirmed by measurement of the
dilation of the suspension as a function of the shear rate.


title:
Impurity Effect on Superconducting Properties in Molecular Substituted
  Organic Superconductor $\kappa$-(ET)$_2$Cu(NCS)$_2$

abstract:
  We report an impurity effect in the organic superconductor
$\kappa$-(ET)$_2$Cu(NCS)$_2$ by substitution of the ET molecule with an
analogue, bis(methyleneditio)tetrathiafulvalene (MT). The superconducting
transition temperature decreases with increasing substitution. The in-plane
magnetic penetration depth is enhanced with substitution, which is
quantitatively attributed to the decrease in the in-plane mean free path. The
enhancement of the penetration depth can also explain the reduction of the
effective pinning in terms of the condensation energy.


title: Physics of Interpulse Emission in Radio Pulsars

abstract:
  The magnetized induced Compton scattering off the particles of the
ultrarelativistic electron-positron plasma of pulsar is considered. The main
attention is paid to the transverse regime of the scattering, which holds in a
moderately strong magnetic field. We specifically examine the problem on
induced transverse scattering of the radio beam into the background, which
takes place in the open field line tube of a pulsar. In this case, the
radiation is predominantly scattered backwards and the scattered component may
grow considerably. Based on this effect, we for the first time suggest a
physical explanation of the interpulse emission observed in the profiles of
some pulsars. Our model can naturally account for the peculiar spectral and
polarization properties of the interpulses. Furthermore, it implies a specific
connection of the interpulse to the main pulse, which may reveal itself in the
consistent intensity fluctuations of the components at different timescales.
Diverse observational manifestations of this connection, including the moding
behavior of PSR B1822-09, the peculiar temporal and frequency structure of the
giant interpulses in the Crab pulsar, and the intrinsic phase correspondence of
the subpulse patterns in the main pulse and the interpulse of PSR B1702-19, are
discussed in detail. It is also argued that the pulse-to-pulse fluctuations of
the scattering efficiency may lead to strong variability of the interpulse,
which is yet to be studied observationally. In particular, some pulsars may
exhibit transient interpulses, i.e. the scattered component may be detectable
only occasionally.


title:
Midrapidity Production of Secondaries in pp Collisions at RHIC and LHC
  Energies in the Quark-Gluon String Model

abstract:
  We consider the phenomenological implications of the assumption that baryons
are systems of three quarks connected through gluon string junction. The
transfer of baryon number in rapidity space due to the string junction
propagation is considered in detail. At high energies this process leads to a
significant effect on the net baryon production in hN collisions at
mid-rapidities. The numerical results for midrapidity inclusive densities of
different secondaries in the framework of the Quark-Gluon String Model are in
reasonable agreement with the experimental data. One universal value lambda ~
0.25 for the strangeness suppression parameter correctly describes the yield
ratios of Lambda/p, Xi/Lambda, and Omega/Xi. The predictions for pp collisions
at LHC energies are also presented.


title:
A deeply embedded young protoplanetary disk around L1489 IRS observed by
  the submillimeter array

abstract:
  Circumstellar disks are expected to form early in the process that leads to
the formation of a young star, during the collapse of the dense molecular cloud
core. It is currently not well understood at what stage of the collapse the
disk is formed or how it subsequently evolves. We aim to identify whether an
embedded Keplerian protoplanetary disk resides in the L1489 IRS system. Given
the amount of envelope material still present, such a disk would respresent a
very young example of a protoplanetary disk. Using the Submillimeter Array
(SMA) we have observed the HCO$^+$ $J=$ 3--2 line with a resolution of about
1$''$. At this resolution a protoplanetary disk with a radius of a few hundred
AUs should be detectable, if present. Radiative transfer tools are used to
model the emission from both continuum and line data. We find that these data
are consistent with theoretical models of a collapsing envelope and Keplerian
circumstellar disk. Models reproducing both the SED and the interferometric
continuum observations reveal that the disk is inclined by 40$^\circ$ which is
significantly different to the surrounding envelope (74$^\circ$). This
misalignment of the angular momentum axes may be caused by a gradient within
the angular momentum in the parental cloud or if L1489 IRS is a binary system
rather than just a single star. In the latter case, future observations looking
for variability at sub-arcsecond scales may be able to constrain these
dynamical variations directly. However, if stars form from turbulent cores, the
accreting material will not have a constant angular momentum axis (although the
average is well defined and conserved) in which case it is more likely to have
a misalignment of the angular momentum axes of the disk and the envelope.


title: Are the nearby groups of galaxies gravitationally bound objects?

abstract:
  We have compared numerical simulations to observations for the nearby (< 40
Mpc) groups of galaxies (Huchra & Geller 1982 and Ramella et al. 2002). The
group identification is carried out using a group-finding algorithm developed
by Huchra and Geller (1982). Using cosmological N-body simulation code with the
LambdaCDM cosmology, we show that the dynamical properties of groups of
galaxies identified from the simulation data are, in general, in a moderate,
within 2sigma, agreement with the observational catalogues of groups of
galaxies. As simulations offer more dynamical information than observations, we
used the N-body simulation data to calculate whether the nearby groups of
galaxies are gravitationally bound objects by using their virial ratio. We show
that in a LambdaCDM cosmology about 20 per cent of nearby groups of galaxies,
identified by the same algorithm as in the case of observations, are not bound,
but merely groups in a visual sense. This is quite significant, specifically
because estimations of group masses in observations are often based on an
assumption that groups of galaxies found by the friends-of-friends algorithm
are gravitationally bound objects. Simulations with different resolutions show
the same results. We also show how the fraction of gravitationally unbound
groups varies when the apparent magnitude limit of the sample and the value of
the cosmological constant is changed. In general, a larger value of the
Omega_Lambda generates slightly more unbound groups.


title:
RR Lyrae stars in Galactic globular clusters. VI. The Period-Amplitude
  relation

abstract:
  We compare theory and observations for fundamental RR Lyrae in the solar
neighborhood and in both Oosterhoff type I (OoI) and type II (OoII) Galactic
globular clusters (GGCs). The distribution of cluster RR_ab in the PA_V plane
depends not only on the metal abundance, but also on the cluster Horizontal
Branch (HB) morphology. On average the observed k_puls parameter, connecting
the period to the visual amplitude, increases when moving from metal-poor to
metal-rich GGCs. However, this parameter shows marginal changes among OoI
clusters with intermediate to red HB types and iron abundances -1.8<= [Fe/H]
<=-1.1, whereas its value decreases in OoII clusters with the bluer HB
morphology. Moreover, at [Fe/H]=-1.7+-0.1 the OoI clusters present redder HB
types and larger <k_puls> values than the OoII clusters. The RR_ab variables in
Omega Cen and in the solar neighborhood further support the evidence that the
spread in [Fe/H], at fixed k_puls, is of the order of +-0.5 dex. Synthetic HB
simulations show that the PA_V plane can provide accurate cluster distance
estimates. The RR_ab variables in OoI and in OoII clusters with very blue HB
types obey a well-defined M_V(RR)-k_puls relation, while those in OoII clusters
with moderately blue HB types present a zero-point that is ~0.05 mag brighter.
Regarding field variables, we show that with [Fe/H]=> -1.0 a unique
M_V(RR)-k_puls relation can be adopted, independently of the parent HB
morphology. Current findings suggest that the PA_V distribution does not seem
to be a robust diagnostic for the metal abundance of RR_ab variables. However,
the same observables can be used to estimate the absolute magnitude of globular
cluster and field RR_ab variables. We show that over the metallicity range
-2.4<= [Fe/H] <= 0.0 the M_V(RR)-[Fe/H] relation shows a parabolic behavior.


title:
Exact Solution of Semi-Flexible and Super-Flexible Interacting Partially
  Directed Walks

abstract:
  We provide the exact generating function for semi-flexible and super-flexible
interacting partially directed walks and also analyse the solution in detail.
We demonstrate that while fully flexible walks have a collapse transition that
is second order and obeys tricritical scaling, once positive stiffness is
introduced the collapse transition becomes first order. This confirms a recent
conjecture based on numerical results. We note that the addition of an
horizontal force in either case does not affect the order of the transition. In
the opposite case where stiffness is discouraged by the energy potential
introduced, which we denote the super-flexible case, the transition also
changes, though more subtly, with the crossover exponent remaining unmoved from
the neutral case but the entropic exponents changing.


title: Maximal regularity for stochastic convolutions driven by Levy noise

abstract:
  We show that the result from Da Prato and Lunardi is valid for stochastic
convolutions driven by L\'evy processes.


title: Longitudinal and Transverse NMR in Superfluid 3He in Anisotropic Aerogel

abstract:
  It was found that NMR properties of both superfluid phases of $^3$He in
anisotropic aerogel can be described in terms of the bulk superfluid order
parameters with the orbital order parameter vector fixed by anisotropy of the
aerogel sample. It was also shown that by a proper squeezing it is possible to
get the aerogel sample with isotropic NMR properties.


title:
A gauge invariant chiral unitary framework for kaon photo- and
  electroproduction on the proton

abstract:
  We present a gauge invariant approach to photoproduction of mesons on
nucleons within a chiral unitary framework. The interaction kernel for
meson-baryon scattering is derived from the chiral effective Lagrangian and
iterated in a Bethe-Salpeter equation. Within the leading order approximation
to the interaction kernel, data on kaon photoproduction from SAPHIR, CLAS and
CBELSA/TAPS are analyzed in the threshold region. The importance of gauge
invariance and the precision of various approximations in the interaction
kernel utilized in earlier works are discussed.


title: Structure theorems for certain Gorenstein ideals

abstract:
  The main achievement of this paper is to provide a structure theorem for
Artinian, Gorenstein local rings with the property that the square of the
maximal ideal is generated by two elements. The moduli problem for this class
of local algebras is also discussed. Finally, upper and lower bounds for the
minimal number of generators of perfect ideals are given.


title:
A fast simulator for polycrystalline processes with application to phase
  change alloys

abstract:
  We present a stochastic simulator for polycrystalline phase-change materials
capable of spatio-temporal modelling of complex anneals. This is based on
consideration of bulk and surface energies to generate rates of growth and
decay of crystallites built up of `monomers' that themselves may be quite
complex molecules. We perform a number of simulations of this model using a
Gillespie algorithm. The simulations are performed at molecular scale and using
an approximation of local free energy changes that depend only on immediate
neighbours. The sites are on a lattice that neither correspond to the crystal
lattice nor to individual monomers, but instead gives information about a
two-state local phase $r$ (where $r=0$ corresponds to amorphous and 1
corresponds to crystalline) and a continuous crystal orientation $\phi$ at each
site.
  As an example we use this to model crystallisation in chalcogenide GST
($GeSbTe$) alloys used for example in phase-change memory devices, where
reversible changes between amorphous and crystalline regimes are used to store
and process information. We use our model to simulate anneals of GST including
ones with non-trivial spatial and temporal variation of temperature; this gives
good agreement to experimental incubation times at low temperatures while
modelling non-trivial crystal size distributions and melting dynamics at higher
temperatures.


title:
Distribution functions of linear combinations of lattice polynomials
  from the uniform distribution

abstract:
  We give the distribution functions, the expected values, and the moments of
linear combinations of lattice polynomials from the uniform distribution.
Linear combinations of lattice polynomials, which include weighted sums, linear
combinations of order statistics, and lattice polynomials, are actually those
continuous functions that reduce to linear functions on each simplex of the
standard triangulation of the unit cube. They are mainly used in aggregation
theory, combinatorial optimization, and game theory, where they are known as
discrete Choquet integrals and Lovasz extensions.


title:
3-Generator Groups whose Elements Commute with Their Endomorphic Images
  Are Abelian

abstract:
  A group in which every element commutes with its endomorphic images is called
an $E$-group.
  Our main result is that all 3-generator $E$-groups are abelian. It follows
that the minimal number of generators of a finitely generated non-abelian
$E$-group is four.


title:
A Semismooth Newton Method for Tikhonov Functionals with Sparsity
  Constraints

abstract:
  Minimization problems in $\ell^2$ for Tikhonov functionals with sparsity
constraints are considered. Sparsity of the solution is ensured by a weighted
$\ell^1$ penalty term. The necessary and sufficient condition for optimality is
shown to be slantly differentiable (Newton differentiable), hence a semismooth
Newton method is applicable. Local superlinear convergence of this method is
proved. Numerical examples are provided which show that our method compares
favorably with existing approaches.


title:
Self-Compression and Controllable Guidance of Multi-Millijoule
  Femtosecond Laser Pulses

abstract:
  Self-compression of multi-millijoule femtosecond laser pulses and dramatic
increase of the peak intensity are found in pressurized helium and neon within
a range of intensity in which the ionization modification of the material
parameters by the pulse is negligible. The pulse propagation is studied by the
(3+1)-dimensional nonlinear Schroedinger equation including basic lowest order
optical processes -- diffraction, group velocity dispersion of second order,
and Kerr nonlinearity of third order. Smooth and well controllable pulse
propagation dynamics is found. Constructing of compressed pulse of controllable
parameters at given space target point can be achieved by a proper chose of the
pulse energy and/or gas pressure.


title: Spin polarization phenomena in dense nuclear matter

abstract:
  Spin polarized states in nuclear matter with an effective nucleon-nucleon
interaction are studied for a wide range of isospin asymmetries and densities.
Based on a Fermi liquid theory, it is shown that there are a few possible
scenarios of spin ordered phase transitions: (a) nuclear matter undergoes at
some critical density a phase transition to a spin polarized state with the
oppositely directed spins of neutrons and protons (Skyrme SLy4 and Gogny D1S
interactions); (b) at some critical density, a spin polarized state with the
like-directed neutron and proton spins appears (Skyrme SkI5 interaction); (c)
nuclear matter under increasing density, at first, undergoes a phase transition
to the state with the opposite directions of neutron and proton spins, which
goes over at larger density to the state with the same direction of nucleon
spins (Skyrme SkI3 interaction).


title: The necessity of dark matter in MOND within galactic scales

abstract:
  To further test MOdified Newtonian Dynamics (MOND) on galactic scales --
originally proposed to explain the rotation curves of disk galaxies without
dark matter -- we study a sample of six strong gravitational lensing early-type
galaxies from the CASTLES database. To determine whether dark matter is present
in these galaxies, we compare the total mass (from lensing) with the stellar
mass content (from a comparison of photometry and stellar population
synthesis). We find that strong gravitational lensing on galactic scales
requires a significant amount of dark matter, even within MOND. On such scales
a 2 eV neutrino cannot explain this excess matter -- in contrast with recent
claims to explain the lensing data of the bullet cluster. The presence of dark
matter is detected in regions with a higher acceleration than the
characteristic MONDian scale of $\sim 10^{-10}$m/s$^2$. This is a serious
challenge to MOND unless the proper treatment of lensing is qualitatively
different (possibly to be developed within a consistent theory such as TeVeS).


title:
Uniform Convergence of the Spectral Expansion for a Differential
  Operator with Periodic Matrix Coefficients

abstract:
  In this paper, we obtain asymptotic formulas for eigenvalues and
eigenfunctions of the operator generated by a system of ordinary differential
equations with summable coefficients and the quasiperiodic boundary conditions.
Using these asymptotic formulas, we find conditions on the coefficients for
which the root functions of this operator form a Riesz basis. Then we obtain
the uniformly convergent spectral expansion of the differential operators with
the periodic matrix coefficients


title: Some epistemic questions of cosmology

abstract:
  We discuss a number of fundamental aspects of modern cosmological concepts,
from the phenomenological, observational, theoretical and epistemic points of
view. We argue that the modern cosmology, despite a great advent, in particular
in the observational sector, is yet to solve important problems, posed already
by the classical times. In particular the stress is put on discerning the
scientific features of modern cosmological paradigms from the more speculative
ones, with the latter immersed in some aspects deeply into mythological world
picture. We finally discuss the principal paradigms, which are present in the
modern cosmological studies and evaluate their epistemic merits.
  KEY WORDS: cosmology, epistemology, methodology, mythology, philosophy of
science


title: A quantile-copula approach to conditional density estimation

abstract:
  We present a new non-parametric estimator of the conditional density of the
kernel type. It is based on an efficient transformation of the data by quantile
transform. By use of the copula representation, it turns out to have a
remarkable product form. We study its asymptotic properties and compare its
bias and variance to competitors based on nonparametric regression.


title: Evolution of primordial black holes in Jordan-Brans-Dicke cosmology

abstract:
  We consider the evolution of primordial black holes in a generalyzed
Jordan-Brans-Dicke cosmological model where both the Brans-Dicke scalar field
and its coupling to gravity are dynamical functions determined from the
evolution equations. The evaporation rate for the black holes changes compared
to that in standard cosmology. We show that accretion of radiation can proceed
effectively in the radiation dominated era. The black hole lifetime shortens
for low initial mass, but increases for high initial mass, and is thus
considerably modified compared to the case of standard cosmology. We derive a
cut-off value for the initial black hole mass, below which primordial black
holes evaporate out in the radiation dominated era, and above which they
survive beyond the present era.


title: Sur l'irr\'eductibilit\'e d'une induite parabolique

abstract:
  Let $F$ be a non-Archimedean locally compact field and let $D$ be a central
division algebra over $F$. Let $\pi_1$ and $\pi_2$ be respectively two smooth
irreducible representations of ${\rm GL}(n_1,D)$ and ${\rm GL}(n_2,F)$, $n_1,
n_2 \geq 0$. In this article, we give some sufficient conditions on $\pi_1$ and
$\pi_2$ so that the parabolically induced representation of $\pi_1 \otimes
\pi_2$ to ${\rm GL}(n_1+n_2,D)$ has a unique irreducible quotient. In the case
where $\pi_1$ is a cuspidal representation, we compute the Zelevinsky's
parameters of such a quotient in terms of parameters of $\pi_2$. This is the
key point for making explicit Howe correspondence for dual pairs of type II.


title:
Two-scale numerical simulation of the weakly compressible 1D isentropic
  Euler equations

abstract:
  Motivated by the difficulty to solve numerically the weakly compressible 1D
isentropic Euler equations with classical methods, we develop in this paper a
two scale numerical method on this model. This method is based on two scale
convergence theory developped by N'Guetseng and Allaire, and finite volume
scheme. Furthermore, we do some numerical simulations in order to verify that
the two-scale numerical method is more and more accurate when the Mach number
diminishes.


title: Quantum nonlocality without entanglement in a pair of qubits

abstract:
  We consider unambiguous discrimination of two separable bipartite states, one
being pure and the other being a rank-2 mixed state. There is a gap between the
optimal success probability under global measurements and the one achieved by
generalized measurements with separable measurement operators. We show that
even the latter success probability cannot be achieved via local operations and
classical communication, leaving a nonzero gap in between.


title:
Dust-grain processing in circumbinary discs around evolved binaries. The
  RV Tauri spectral twins RU Cen and AC Her

abstract:
  Context: We study the structure and evolution of circumstellar discs around
evolved binaries and their impact on the evolution of the central system. Aims:
To study in detail the binary nature of RUCen and ACHer, as well as the
structure and mineralogy of the circumstellar environment. Methods: We combine
multi-wavelength observations with a 2D radiative transfer study. Our radial
velocity program studies the central stars, while our Spitzer spectra and
broad-band SEDs are used to constrain mineralogy, grain sizes and physical
structure of the circumstellar environment. Results: We determine the orbital
elements of RUCen showing that the orbit is highly eccentric with a rather long
period of 1500 days. The infrared spectra of both objects are very similar and
the spectral dust features are dominated by Mg-rich crystalline silicates. The
small peak-to-continuum ratios are interpreted as being due to large grains.
Our model contains two components with a cold midplain dominated by large
grains, and the near- and mid-IR which is dominated by the emission of smaller
silicates. The infrared excess is well modelled assuming a hydrostatic passive
irradiated disc. The profile-fitting of the dust resonances shows that the
grains must be very irregular. Conclusions: These two prototypical RVTauri
pulsators with circumstellar dust are binaries where the dust is trapped in a
stable disc. The mineralogy and grain sizes show that the dust is highly
processed, both in crystallinity and grain size. The cool crystals show that
either radial mixing is very efficient and/or that the thermal history at grain
formation has been very different from that in outflows. The physical processes
governing the structure of these discs are similar to those observed in
protoplanetary discs around young stellar objects.


title: Temperature fluctuations of interstellar dust grains

abstract:
  The temperatures of interstellar dust grains are analyzed using stochastic
simulations, taking into account the grain composition and size and the
discreteness of the photon flux. [...] The distribution of grain temperatures
is calculated for a broad range of grain sizes and for different intensities of
the interstellar radiation field, relevant to diffuse clouds and to PDRs. The
dependence of the average grain temperature on its size is shown for different
irradiation intensities. It is found that the average temperatures of grains
with radii smaller than about 0.02 $\mu$m are reduced due to the fluctuations.
The average temperatures of grains of radii larger than about 0.35 $\mu$m are
also slightly reduced due to their more efficient emission of infrared
radiation, particularly when exposed to high irradiation intensities. The
average temperatures <T> of silicate and carbonaceous grains are found to
depend on the radiation field intensity X_MMP according to <T>~X_MMP^gamma,
where the exponent gamma depends on the grain size and composition. This
fitting formula is expected to be useful in simulations of interstellar
processes, and can replace commonly used approximations which do not account
for the grain temperature fluctuations and for the detailed properties of
interstellar dust particles. The implications of the results on molecular
hydrogen formation are also discussed. It is concluded that grain-temperature
fluctuations tend to reduce the formation rate of molecular hydrogen, and
cannot account for the observations of H_2 in photon dominated regions, even in
the presence of chemisorption sites.


title:
Spitzer Space Telescope spectral observations of AGB stars in the Fornax
  dwarf spheroidal galaxy

abstract:
  We have observed five carbon-rich AGB stars in the Fornax dwarf spheroidal
(dSph) galaxy, using the Infrared Spectrometer on board the Spitzer Space
Telescope. The stars were selected from a near-infrared survey of Fornax and
include the three reddest stars, with presumably the highest mass-loss rates,
in that galaxy. Such carbon stars probably belong to the intermediate-age
population (2-8 Gyr old and metallicity of [Fe/H] -1) of Fornax. The primary
aim of this paper is to investigate mass-loss rate, as a function of luminosity
and metallicity, by comparing AGB stars in several galaxies with different
metallicities. The spectra of three stars are fitted with a radiative transfer
model. We find that mass-loss rates of these three stars are 4-7x10^-6 Msun
yr-1. The other two stars have mass-loss rates below 1.3x10^-6 Msun yr-1. We
find no evidence that these rates depend on metallicity, although we do suggest
that the gas-to-dust ratio could be higher than at solar metallicity, in the
range 240 to 800. The C2H2 bands are stronger at lower metallicity because of
the higher C/O ratio. In contrast, the SiC fraction is reduced at low
metallicity, due to low silicon abundance. The total mass-loss rate from all
known carbon-rich AGB stars into the interstellar medium of this galaxy is of
the order of 2x10^-5 Msun yr-1. This is much lower than that of the dwarf
irregular galaxy WLM, which has a similar visual luminosity and metallicity.
The difference is attributed to the younger stellar population of WLM. The
suppressed gas-return rate to the ISM accentuates the difference between the
relatively gas-rich dwarf irregular and the gas-poor dwarf spheroidal galaxies.
Our study will be useful to constrain gas and dust recycling processes in low
metallicity galaxies.


title: Fano manifolds and blow-ups of low-dimensional subvarieties

abstract:
  We study Fano manifolds of pseudoindex greater than one and dimension greater
than five, which are blow-ups of smooth varieties along smooth centers of
dimension equal to the pseudoindex of the manifold. We obtain a classification
of the possible cones of curves of these manifolds, and we prove that there is
only one such manifold without a fiber type elementary contraction.


title:
An impact of the metrics probabilistic distributions on the spatial
  geometry of the universe in quantum model

abstract:
  It is shown that the homogeneous and isotropic Universe is spatially flat in
the limit which takes into account the moments of infinitely large orders of
probabilistic distribution of a scale factor with respect to its mean value in
the state with large quantum numbers. The quantum mechanism of fine tuning of
the total energy density in the Universe to the critical value at the early
stage of its evolution is proposed and the reason of possible small difference
between these densities during the subsequent expansion is indicated. A
comparison of the predictions of the quantum model with the real Universe is
given.


title: Local rigidity of surfaces in space forms

abstract: This paper is withdrawn.


title: Modeling Metropolis Public Transport

abstract:
  We present results of a survey of public transport networks (PTNs) of
selected 14 major cities of the world with PTN sizes ranging between 2000 and
46000 stations and develop an evolutionary model of these networks. The
structure of these PTNs is revealed in terms of a set of neighbourhood
relations both for the routes and the stations. The networks defined in this
way display distinguishing properties due to the constraints of the embedding
2D geographical space and the structure of the cities. In addition to the
standard characteristics of complex networks like the number of nearest
neighbours, mean path length, and clustering we observe features specific to
PTNs. While other networks with real-world links like cables or neurons
embedded in two or three dimensions often show similar behavior, these can be
studied in detail in our present case. Geographical data for the routes reveal
surprising self-avoiding walk properties that we relate to the optimization of
surface coverage. We propose and simulate an evolutionary growth model based on
effectively interacting self-avoiding walks that reproduces the key features of
PTN.


title:
Spin wave resonances in La_{0.7}Sr_{0.3}MnO_{3} films: measurement of
  spin wave stiffness and anisotropy field

abstract:
  We studied magnetic field dependent microwave absorption in epitaxial
La$_{0.7}$Sr$_{0.3}$MnO$_{3}$ films using an X-band Bruker ESR spectrometer. By
analyzing angular and temperature dependence of the ferromagnetic and spin-wave
resonances we determine spin-wave stiffness and anisotropy field. The spin-wave
stiffness as found from the spectrum of the standing spin-wave resonances in
thin films is in fair agreement with the results of inelastic neutron
scattering studies on a single crystal of the same composition [Vasiliu-Doloc
et al., J. Appl. Phys. \textbf{83}, 7343 (1998)].


title: Large volume behavior of Yang-Mills propagators

abstract:
  We summarize results on finite-volume effects in the propagators of Landau
gauge Yang-Mills theory using Dyson-Schwinger equations on a 4-dimensional
torus. We demonstrate explicitly how the solutions for the gluon and the ghost
propagator tend towards their respective infinite volume forms in the
corresponding limit. We discuss the relation of our solutions with results from
lattice Monte-Carlo simulations.


title: Attack Vulnerability of Public Transport Networks

abstract:
  The behavior of complex networks under attack depends strongly on the
specific attack scenario. Of special interest are scale-free networks, which
are usually seen as robust under random failure or attack but appear to be
especially vulnerable to targeted attacks. In a recent study of public
transport networks of 14 major cities of the world we have shown that these
networks may exhibit scale-free behaviour [Physica A 380, 585 (2007)]. Our
further analysis, subject of this report, focuses on the effects that defunct
or removed nodes have on the properties of public transport networks.
Simulating different attack strategies we elaborate vulnerability criteria that
allow to find minimal strategies with high impact on these systems.