title:
Astrophysically Triggered Searches for Gravitational Waves: Status and
  Prospects

abstract:
  In gravitational-wave detection, special emphasis is put onto searches that
focus on cosmic events detected by other types of astrophysical observatories.
The astrophysical triggers, e.g. from gamma-ray and X-ray satellites, optical
telescopes and neutrino observatories, provide a trigger time for analyzing
gravitational wave data coincident with the event. In certain cases the
expected frequency range, source energetics, directional and progenitor
information is also available. Beyond allowing the recognition of gravitational
waveforms with amplitudes closer to the noise floor of the detector, these
triggered searches should also lead to rich science results even before the
onset of Advanced LIGO. In this paper we provide a broad review of LIGO's
astrophysically triggered searches and the sources they target.


title: Bright solitary waves of atomic Bose-Einstein condensates under rotation

abstract:
  We analyse the rotation of bright solitary waves formed of atomic
Bose-Einstein condensates with attractive atomic interactions. By employing a
variational technique and assuming an irrotational quadrupolar flow field, we
map out the variational solutions in the rotating frame. In particular, we show
that rotation has a considerable stabilising effect on the system,
significantly raising the critical threshold for collapse of the bright
solitary waves.


title:
Spins of the supermassive black hole in M87: new constraints from TeV
  observations

abstract:
  The rapid TeV $\gamma-$ray variability detected in the well-known nearby
radio galaxy M87 implies an extremely compact emission region (5-10
Schwarzschild radii) near the horizon of the supermassive black hole in the
galactic center. TeV photons are affected by dilution due to interaction with
the radiation field of the advection-dominated accretion flow (ADAF) around the
black hole, and can thus be used to probe the innermost regions around the
black hole. We calculate the optical depth of the ADAF radiation field to the
TeV photons and find it strongly depends on the spin of the black hole. We find
that transparent radii of 10 TeV photons are of $5R_{\rm S}$ and $13R_{\rm S}$
for the maximally rotating and non-rotating black holes, respectively. With the
observations, the calculated transparent radii strongly suggest the black hole
is spinning fast in the galaxy. TeV photons could be used as a powerful
diagnostic for estimating black hole spins in galaxies in the future.


title: Non-singular affine surfaces with self-maps

abstract:
  We classify surjective self-maps (of degree at least two) of affine surfaces
according to the log Kodaira dimension.


title: Proof of the Atmospheric Greenhouse Effect

abstract:
  A recently advanced argument against the atmospheric greenhouse effect is
refuted. A planet without an infrared absorbing atmosphere is mathematically
constrained to have an average temperature less than or equal to the effective
radiating temperature. Observed parameters for Earth prove that without
infrared absorption by the atmosphere, the average temperature of Earth's
surface would be at least 33 K lower than what is observed.


title: A Simple Yao-Yao-Based Spanner of Bounded Degree

abstract:
  It is a standing open question to decide whether the Yao-Yao structure for
unit disk graphs (UDGs) is a length spanner of not. This question is highly
relevant to the topology control problem for wireless ad hoc networks. In this
paper we make progress towards resolving this question by showing that the
Yao-Yao structure is a length spanner for UDGs of bounded aspect ratio. We also
propose a new local algorithm, called Yao-Sparse-Sink, based on the Yao-Sink
method introduced by Li, Wan, Wang and Frieder, that computes a (1+e)-spanner
of bounded degree for a given UDG and for given e > 0. The Yao-Sparse-Sink
method enables an efficient local computation of sparse sink trees. Finally, we
show that all these structures for UDGs -- Yao, Yao-Yao, Yao-Sink and
Yao-Sparse-Sink -- have arbitrarily large weight.


title:
The Generation of Textual Entailment with NLML in an Intelligent
  Dialogue system for Language Learning CSIEC

abstract:
  This research report introduces the generation of textual entailment within
the project CSIEC (Computer Simulation in Educational Communication), an
interactive web-based human-computer dialogue system with natural language for
English instruction. The generation of textual entailment (GTE) is critical to
the further improvement of CSIEC project. Up to now we have found few
literatures related with GTE. Simulating the process that a human being learns
English as a foreign language we explore our naive approach to tackle the GTE
problem and its algorithm within the framework of CSIEC, i.e. rule annotation
in NLML, pattern recognition (matching), and entailment transformation. The
time and space complexity of our algorithm is tested with some entailment
examples. Further works include the rules annotation based on the English
textbooks and a GUI interface for normal users to edit the entailment rules.


title: Irreversibility of entanglement loss

abstract:
  The action of a channel on a quantum system, when non trivial, always causes
deterioration of initial quantum resources, understood as the entanglement
initially shared by the input system with some reference purifying it. One
effective way to measure such a deterioration is by measuring the loss of
coherent information, namely the difference between the initial coherent
information and the final one: such a difference is ``small'', if and only if
the action of the channel can be ``almost perfectly'' corrected with
probability one. In this work, we generalise this result to different
entanglement loss functions, notably including the entanglement of formation
loss, and prove that many inequivalent entanglement measures lead to equivalent
conditions for approximate quantum error correction. In doing this, we show how
different measures of bipartite entanglement give rise to corresponding
distance-like functions between quantum channels, and we investigate how these
induced distances are related to the cb-norm.


title: On the Equivalence of Primal and Dual Substructuring Preconditioners

abstract:
  After a short historical review, we present four popular substructuring
methods: FETI-1, BDD, FETI-DP, BDDC, and derive the primal versions to the two
FETI methods, called P-FETI-1 and P-FETI-DP, as proposed by Fragakis and
Papadrakakis. The formulation of the BDDC method shows that it is the same as
P-FETI-DP and the same as a preconditioner introduced by Cros. We prove the
equality of eigenvalues of a particular case of the FETI-1 method and of the
BDD method by applying a recent abstract result by Fragakis.


title:
Quantum analysis of shot noise suppression in a series of tunnel
  barriers

abstract:
  We report the results of an analysis, based on a straightforward
quantum-mechanical model, of shot noise suppression in a structure containing
cascaded tunneling barriers. Our results exhibit a behavior that is in sharp
contrast with existing semiclassical models for this particular type of
structure, which predict a limit of 1/3 for the Fano factor as the number of
barriers is increased. The origin of this discrepancy is investigated and
attributed to the presence of localization on the length scale of the mean free
path, as a consequence of the strictly 1-dimensional nature of disorder, which
does not create mode mixing, while no localization appears in common
semiclassical models. We expect localization to be indeed present in practical
situations with prevalent 1-D disorder, and the existing experimental evidence
appears to be consistent with such a prediction.


title:
Eigenvalue Estimates and Mutual Information for the Linear Time-Varying
  Channel

abstract:
  We consider linear time-varying channels with additive white Gaussian noise.
For a large class of such channels we derive rigorous estimates of the
eigenvalues of the correlation matrix of the effective channel in terms of the
sampled time-varying transfer function and, thus, provide a theoretical
justification for a relationship that has been frequently observed in the
literature. We then use this eigenvalue estimate to derive an estimate of the
mutual information of the channel. Our approach is constructive and is based on
a careful balance of the trade-off between approximate operator
diagonalization, signal dimension loss, and accuracy of eigenvalue estimates.


title: A note on evaluations of multiple zeta values

abstract:
  Multiple zeta values (MZVs) with certain repeated arguments or certain sums
of cyclically generated MZVs are evaluated as rational multiple of powers of
$\pi^2$. In this paper, we give a short and simple proof of the remarkable
evaluations of MZVs established by D. Borman and D. M. Bradley.


title:
Density matrix numerical renormalization group for non-Abelian
  symmetries

abstract:
  We generalize the spectral sum rule preserving density matrix numerical
renormalization group (DM-NRG) method in such a way that it can make use of an
arbitrary number of not necessarily Abelian, local symmetries present in the
quantum impurity system. We illustrate the benefits of using non-Abelian
symmetries by the example of calculations for the T-matrix of the two-channel
Kondo model in the presence of magnetic field, for which conventional NRG
methods produce large errors and/or take a long run-time.


title: Constructions of regular algebras $L_p^w(G)$

abstract:
  Criterion of (Shilov) regularity for weighted algebras $L_1^w(G)$ on a
locally compact abelian group $G$ is known by works of Beurling (1949) and
Domar (1956). In the present paper this criterion is extended to translation
invariant weighted algebras $L_p^w(G)$ with $p>1$. Regular algebras $L_p^w(G)$
are constructed on any sigma-compact abelian group $G$. It was proved earlier
by the author that sigma-compactness is necessary (in the abelian case) for the
existence of weighted algebras $L_p^w(G)$ with $p>1$.


title:
Topological density fluctuations and gluon condensate around confining
  string in Yang-Mills theory

abstract:
  We study the structure of the confining string in Yang-Mills theory using the
method of the field strength correlators. The method allows us to demonstrate
that both the local fluctuations of the topological charge and the gluon
condensate are suppressed in the vicinity of the string axis in agreement with
results of lattice simulations.


title: Gravitational Waves as a Probe of the Gravitino Mass

abstract:
  If gaugino condensations occur in the early universe, domain walls are
produced as a result of the spontaneous breaking of a discrete R symmetry.
Those domain walls eventually annihilate with one another, producing the
gravitational waves. We show that the gravitational waves can be a probe for
measuring the gravitino mass, if the constant term in the superpotential is the
relevant source of the discrete R symmetry breaking.


title: Investigation on light dark matter

abstract:
  Some extensions of the Standard Model provide Dark Matter candidate particles
with sub-GeV mass. These Light Dark Matter particles have been considered for
example in Warm Dark Matter scenarios (e.g. the keV scale sterile neutrino,
axino or gravitino). Moreover MeV scale DM candidates have been proposed in
supersymmetric models and as source of the 511 keV line from the Galactic
center. In this paper the possibility of direct detection of a Light Dark
Matter candidate is investigated considering the inelastic scattering processes
on the electron or on the nucleus targets. Some theoretical arguments are
developed and related phenomenological aspects are discussed. Allowed volumes
and regions for the characteristic phenomenological parameters of the
considered scenarios are derived from the DAMA/NaI annual modulation data.


title: Remarks upon Neutrino Mixing Hypothesis

abstract:
  It is shown that various versions of the neutrino mixing hypothesis are in a
contradiction with generally accepted facts and principles.There is also
presented the possible alternative formulation of the neutrino oscillation
theory and it is shown under what conditions this theory reproduces the known
oscillation probability formula. In our approach (flavor) neutrinos are Dirac
particles. In the case of Majorana neutrinos, or the nonrelativistic neutrinos
(i.e. relic neutrinos) the problem could be more complicated.


title: Algebraization of bundles on non-proper schemes

abstract:
  We consider the algebraization problem for principal bundles with reductive
structure group, defined on the complement of a closed subset Z in a proper
formal scheme. We show that, when Z is of codimension at least 3, an
algebraization always exists. For codimension 2 we show that an algebraization
exists precisely when a certain additional condition is satisfied.


title:
A FDR-consistent field theory for the stochastic dynamic density
  functional model

abstract:
  We present a brief review of our recent efforts to develop a FDR-preserving
field theory for the stochastic dynamic density functional model, emphasizing
the essential structure of the theory.


title: Status of GRB Observations with the Suzaku Wideband All-sky Monitor

abstract:
  The Wide-band All-sky Monitor (WAM) is a function of the large lateral BGO
shield of the Hard X-ray Detector (HXD) onboard Suzaku. Its large geometrical
area of 800 cm^2 per side, the large stopping power for the hard X-rays and the
wide-field of view make the WAM an ideal detector for gamma-ray bursts (GRBs)
observations in the energy range of 50-5000 keV. In fact, the WAM has observed
288 GRBs confirmed by other satellites, till the end of May 2007.


title: Concepts of Symmetry in the Work of Wolfgang Pauli

abstract:
  "Symmetry" was one of the most important methodological themes in
20th-century physics and is probably going to play no lesser role in physics of
the 21st century. As used today, there are a variety of interpretations of this
term, which differ in meaning as well as their mathematical consequences.
Symmetries of crystals, for example, generally express a different kind of
invariance than gauge symmetries, though in specific situations the
distinctions may become quite subtle. I will review some of the various notions
of "symmetry" and highlight some of their uses in specific examples taken from
Pauli's scientific oevre.


title: Moving system with speeded-up evolution

abstract:
  In the classical (non-quantum) relativity theory the course of the moving
clock is dilated as compared to the course of the clock at rest (the Einstein
dilation). Any unstable system may be regarded as a clock. The time evolution
(e.g., the decay) of a uniformly moving physical system is considered using the
relativistic quantum theory. The example of a moving system is given whose
evolution turns out to be speeded-up instead of being dilated. A discussion of
this paradoxical result is presented.


title: Spin Triplet Excitations for a Valence Bond Solid on the Kagome Lattice

abstract:
  One of the most promising candidate ground states for the quantum
antiferromagnetic Heisenberg model on the Kagome lattice is the valence bond
solid (VBS) with a 36-site unit cell. We present a theory of triplet excitation
spectra about this ground state using bond operator formalism. In particular we
obtain dispersions of all 18 triplet modes in the reduced Brillouin zone. In
the bond operator mean-field theory, it is found that a large number of triplet
modes are non-dispersive. In particular, the lowest triplet excitation is
non-dispersive and degenerate with a dispersive mode at the zone center. Away
from the zone center, the lowest triplet is separated from two other flat modes
by a small energy gap. Quantum fluctuations are considered by taking into
account scattering processes of two triplets and their bound state formation,
which leads to a downward renormalization of the lowest spin triplet gap. The
dispersion of the lowest triplet excitation in the VBS state is compared with
the dispersive lower bound of the triplet continuum expected in competing spin
liquid phases. Implications to future neutron scattering experiments are
discussed.


title: An Improved Scheme for Initial Ranging in OFDMA-based Networks

abstract:
  An efficient scheme for initial ranging has recently been proposed by X. Fu
et al. in the context of orthogonal frequency-division multiple-access (OFDMA)
networks based on the IEEE 802.16e-2005 standard. The proposed solution aims at
estimating the power levels and timing offsets of the ranging subscriber
stations (RSSs) without taking into account the effect of possible carrier
frequency offsets (CFOs) between the received signals and the base station
local reference. Motivated by the above problem, in the present work we design
a novel ranging scheme for OFDMA in which the ranging signals are assumed to be
misaligned both in time and frequency. Our goal is to estimate the timing
errors and CFOs of each active RSS. Specifically, CFO estimation is
accomplished by resorting to subspacebased methods while a least-squares
approach is employed for timing recovery. Computer simulations are used to
assess the effectiveness of the proposed solution and to make comparisons with
existing alternatives.


title: The Rich Structure of Minkowski Space

abstract:
  Minkowski Space is the simplest four-dimensional Lorentzian Manifold, being
topologically trivial and globally flat, and hence the simplest model of
spacetime--from a General-Relativistic point of view. But this does not mean
that it is altogether structurally trivial. In fact, it has a very rich
structure, parts of which will be spelled out in detail in this contribution.
This will contain elementary aspects of affine spaces, various paths to the
Poincare group, the lattices of causally and chronologically complete regions,
and last but not least, the Noether-Herglotz theorem.


title:
Ergodicity and Slowing Down in Glass-Forming Systems with Soft
  Potentials: No Finite-Temperature Singularities

abstract:
  The aim of this paper is to discuss some basic notions regarding generic
glass forming systems composed of particles interacting via soft potentials.
Excluding explicitly hard-core interaction we discuss the so called `glass
transition' in which super-cooled amorphous state is formed, accompanied with a
spectacular slowing down of relaxation to equilibrium, when the temperature is
changed over a relatively small interval. Using the classical example of a
50-50 binary liquid of N particles with different interaction length-scales we
show that (i) the system remains ergodic at all temperatures. (ii) the number
of topologically distinct configurations can be computed, is temperature
independent, and is exponential in N. (iii) Any two configurations in phase
space can be connected using elementary moves whose number is polynomially
bounded in N, showing that the graph of configurations has the `small world'
property. (iv) The entropy of the system can be estimated at any temperature
(or energy), and there is no Kauzmann crisis at any positive temperature. (v)
The mechanism for the super-Arrhenius temperature dependence of the relaxation
time is explained, connecting it to an entropic squeeze at the glass
transition. (vi) There is no Vogel-Fulcher crisis at any finite temperature T>0


title:
The soft X-ray properties of AGN from the CJF sample; A correlation
  analysis between soft X-ray and VLBI properties

abstract:
  Context: We present the soft X-ray properties obtained in the ROSAT All-Sky
survey and from pointed PSPC observations for the AGN in the complete
flux-density limited Caltech-Jodrell Bank flat spectrum sample (hereafter CJF).
CJF is a VLBI survey (VLBA observations at 5 GHz) of 293 AGN with detailed
information on jet component motion. Aims: We investigate and discuss the soft
X-ray properties of this AGN sample and examine the correlations between X-ray
and VLBI properties, test beaming scenarios, and search for the discriminating
properties between the sub-samples detected and not detected by ROSAT. Methods:
Comparing the observed and the predicted X-ray fluxes by assuming an Inverse
Compton (IC) origin for the observed X-rays, we compute the beaming or Doppler
factor and contrast the Doppler factors with other beaming indicators derived
from the VLBI observations, such as the value of the expansion velocity, and
the observed and intrinsic brightness temperature. In addition, we investigate
the large-scale radio structure of the AGN and the difference between the pc-
and kpc-scale structure (misalignment) with regard to the X-ray
observations.Results: We find a nearly linear relation between X-ray and radio
luminosities, and a similar but less stringent behaviour for the relation
between optical and X-ray luminosities. The quasars detected by ROSAT have a
different $\beta_{\rm app}$-redshift relationship compared to the non-detected
ones. ROSAT-detected sources tend to reveal extended large-scale radio
structures more often. Conclusions: We conclude that beaming alone cannot
explain the observed dichotomy of ROSAT detection or non-detection and assume
that the large-scale jet structure plays a decisive role.


title: The dynamical structure of dark matter haloes

abstract:
  Thanks to the ever increasing computational power and the development of more
sophisticated algorithms, numerical N-body simulations are now uncovering
several phenomenological relations between the physical properties of dark
matter haloes in position and velocity space. It is the aim of the present work
to investigate in detail the dynamical structure of dark matter haloes, as well
as its possible dependence on mass and its evolution with redshift up to z=5.
We use high-resolution cosmological simulations of individual objects to
compute the radially-averaged profiles of several quantities, scaled by the
radius Rmax at which the circular velocity attains its maximum value, Vmax. No
systematic dependence on mass or cosmic epoch are found within Rmax, and all
the different radial profiles are well fit by simple analytical models.
However, our results suggest that several properties are not `universal'
outside this radius. [Abridged]


title:
Particle Motion and Electromagnetic Fields of Rotating Compact
  Gravitating Objects with Gravitomagnetic Charge

abstract:
  The exact solution for the electromagnetic field occuring when the
Kerr-Taub-NUT compact object is immersed (i) in an originally uniform magnetic
field aligned along the axis of axial symmetry (ii) in dipolar magnetic field
generated by current loop has been investigated. Effective potential of motion
of charged test particle around Kerr-Taub-NUT gravitational source immersed in
magnetic field with different values of external magnetic field and NUT
parameter has been also investigated. In both cases presence of NUT parameter
and magnetic field shifts stable circular orbits in the direction of the
central gravitating object. Finally we find analytical solutions of Maxwell
equations in the external background spacetime of a slowly rotating magnetized
NUT star. The star is considered isolated and in vacuum, with monopolar
configuration model for the stellar magnetic field.


title: Role of Symmetry and Geometry in a chaotic Pseudo-Random Bit Generator

abstract:
  In this work, Pseudo-Random Bit Generation (PRBG) based on 2D chaotic
mappings of logistic type is considered. The sequences generated with two
Pseudorandom Bit Generators (PRBGs) of this type are statistically tested and
the computational effectiveness of the generators is estimated. The role played
by the symmetry and the geometrical properties of the underlying chaotic
attractors is also explored. Considering these PRBGs valid for cryptography,
the size of the available key spaces are calculated. Additionally, a novel
mechanism called 'symmetry-swap' is introduced in order to enhance the PRBG
algorithm. It is shown that it can increase the degrees of freedom of the key
space, while maintaining the speed and performance in the PRBG.


title: The young population of the Chamaeleon II dark cloud

abstract:
  We discuss the results of the optical spectroscopic follow-up of pre-main
sequence (PMS) objects and candidates selected in the Chamaeleon II dark cloud
based on data from the Spitzer Legacy survey "From Molecular Cores to Planet
Forming Disks" (c2d) and from previous surveys. Our sample includes both
objects with infrared excess selected according to c2d criteria and referred to
as Young Stellar Objects and other cloud members and candidates selected from
complementary optical and near-infrared data. We characterize the sample of
objects by deriving their physical parameters. The vast majority of objects
have masses < 1 solar mass and ages < 6 Myr. Several of the PMS objects and
candidates lie very close to or below the Hydrogen-burning limit. A first
estimate of the slope of the Initial Mass Function in Cha II is consistent with
that of other T associations. The star formation efficiency in the cloud (1-4%)
is consistent with our own estimates for Taurus and Lupus, but significantly
lower than for Cha I. This might mean that different star-formation activities
in the Chamaeleon clouds may reflect a different history of star formation. We
also find that the Cha II cloud is turning some 8 solar masses into stars every
Myr, which is less than the star formation rate in the other c2d clouds.
However, the star formation rate is not steady and evidence is found that the
star formation in Cha II might have occurred very rapidly. The H_alpha emission
of the Cha II PMS objects, as well as possible correlations between their
stellar and disk properties, are also investigated.


title: Klein-Gordon-Maxwell System in a bounded domain

abstract:
  This paper is concerned with the Klein-Gordon-Maxwell system in a bounded
spatial domain. We discuss the existence of standing waves
$\psi=u(x)e^{-i\omega t}$ in equilibrium with a purely electrostatic field
$\mathbf{E}=-\nabla\phi(x)$. We assume an homogeneous Dirichlet boundary
condition on $u$ and an inhomogeneous Neumann boundary condition on $\phi$. In
the "linear" case we characterize the existence of nontrivial solutions for
small boundary data. With a suitable nonlinear perturbation in the matter
equation, we get the existence of infinitely many solutions.


title: The oblique parameters in multi-Higgs-doublet models

abstract:
  We present general expressions for the oblique parameters S, T, U, V, W, and
X in the SU(2)xU(1) electroweak model with an arbitrary number of scalar SU(2)
doublets, with hypercharge 1/2, and an arbitrary number of scalar SU(2)
singlets.


title: Warm hilltop inflation

abstract:
  We study the low-temperature limit of warm inflation in a hilltop model. This
limit remains valid up to the end of inflation, allowing an analytic
description of the entire inflationary stage. In the weak dissipative regime,
if the kinetic density of the inflaton dominates after inflation, low scale
inflation is attained with Hubble scale as low as 1 GeV. In the strong
dissipative regime, the model satisfies the observational requirements for the
spectral index with a mild tuning of the model parameters, while also
overcoming the $\eta$-problem of inflation. However, there is some danger of
gravitino overproduction unless the particle content of the theory is large.


title: Multi-Cell Traps for Registering of Cold Atom Clouds

abstract:
  In this letter, the results on the development and simulation of new
three-dimensional nanotraps for cold dressed atoms are considered. The traps
are the multi-cell structures built by crossed non-touching carbon nanotubes.
The trapping effect is tuned by the DC and RF currents to confine the strong-
or low-potential seeking atoms far enough from the areas of strong
Casimir-Polder and spin-flip forces. It is supposed that the developed and
simulated multi-cell structures are pertinent for catching the Bose-Einstein
condensates to demonstrate the Josephson effect, and to enable the study of the
entanglement of confined clouds in three-dimensional nano-cells.


title: On canonical pairs in 2-transverse-mode DOPOs

abstract:
  In ref. [1] we analyzed the properties of a Degenerate Optical Parametric
Oscillator (DOPO) tuned to the first transverse mode family at the signal
frequency. Above threshold, a Hermite-Gauss mode with an arbitrary orientation
in the transverse plane is emitted, and thus the rotational invariance of the
system is broken. When quantum effects were taken into account, it was found on
the one hand, that quantum noise is able to induce a random rotation on this
classically emitted mode. On the other hand, the analysis of a balanced
homodyne detection in which the local oscillator (LO) was orthogonal to the
excited mode at any time, showed that squeezing in the quadrature selected by
the LO was found for every phase of this one, squeezing being perfect for a
pi/2 phase. This last fact revealed an apparent paradox: If all quadratures are
below shot noise level, the uncertainty principle seems to be violated. In [1]
we stated that the explanation behind this paradox is that the quadratures of
the rotating orthogonal mode do not form a canonical pair, and the extra noise
is transferred to the diffusing orientation. Thes notes are devoted to prove
this claim.


title:
Exact sequences of fibrations of crossed complexes, homotopy
  classification of maps, and nonabelian extensions of groups

abstract:
  The classifying space of a crossed complex generalises the construction of
Eilenberg-Mac Lane spaces. We show how the theory of fibrations of crossed
complexes allows the analysis of homotopy classes of maps from a free crossed
complex to such a classifying space. This gives results on the homotopy
classification of maps from a CW-complex to the classifying space of a crossed
module and also, more generally, of a crossed complex whose homotopy groups
vanish in dimensions between 1 and n. The results are analogous to those for
the obstruction to an abstract kernel in group extension theory.


title: On the spectrum of the Stokes operator

abstract:
  We prove Li--Yau-type lower bounds for the eigenvalues of the Stokes operator
and give applications to the attractors of the Navier--Stokes equations.


title: A palindromization map for the free group

abstract:
  We define a self-map Pal: F_2 --> F_2 of the free group on two generators a,
b, using automorphisms of F_2 that form a group isomorphic to the braid group
B_3. The map Pal restricts to de Luca's right iterated palindromic closure on
the submonoid generated by a, b, and is continuous for the profinite topology
on F_2. The values of Pal are palindromes and coincide with the elements g of
F_2 such that abg is conjugate to bag.


title: Magnetic edge states in graphene in nonuniform magnetic fields

abstract:
  We theoretically study electronic properties of a graphene sheet on xy plane
in a spatially nonuniform magnetic field, $B = B_0 \hat{z}$ in one domain and
$B = B_1 \hat{z}$ in the other domain, in the quantum Hall regime and in the
low-energy limit. We find that the magnetic edge states of the Dirac fermions,
formed along the boundary between the two domains, have features strongly
dependent on whether $B_0$ is parallel or antiparallel to $B_1$. In the
parallel case, when the Zeeman spin splitting can be ignored, the magnetic edge
states originating from the $n=0$ Landau levels of the two domains have
dispersionless energy levels, contrary to those from the $n \ne 0$ levels.
Here, $n$ is the graphene Landau-level index. They become dispersive as the
Zeeman splitting becomes finite or as an electrostatic step potential is
additionally applied. In the antiparallel case, the $n=0$ magnetic edge states
split into electron-like and hole-like current-carrying states. The energy gap
between the electron-like and hole-like states can be created by the Zeeman
splitting or by the step potential. These features are attributed to the fact
that the pseudo-spin of the magnetic edge states couples to the direction of
the magnetic field. We propose an Aharonov-Bohm interferometry setup in a
graphene ribbon for experimental study of the magnetic edge states.


title: Multiscale Analysis of Reaction Networks

abstract:
  In most natural sciences there is currently the insight that it is necessary
to bridge gaps between different processes which can be observed on different
scales. This is especially true in the field of chemical reactions where the
abilities to form bonds between different types of atoms and molecules create
much of the properties we experience in our everyday life, especially in all
biological activity. There are essentially two types of processes related to
biochemical reaction networks, the interactions among molecules and
interactions involving their conformational changes, so in a sense, their
internal state. The first type of processes can be conveniently approximated by
the so-called mass-action kinetics, but this is not necessarily so for the
second kind where molecular states do not define any kind of density or
concentration. In this paper we demonstrate the necessity to study reaction
networks in a stochastic formulation for which we can construct a coherent
approximation in terms of specific space-time scales and the number of
particles. The continuum limit procedure naturally creates equations of
Fokker-Planck type where the evolution of the concentration occurs on a slower
time scale when compared to the evolution of the conformational changes, for
example triggered by binding or unbinding events with other (typically smaller)
molecules. We apply the asymptotic theory to derive the effective, i.e.
macroscopic dynamics of the biochemical reaction system. The theory can also be
applied to other processes where entities can be described by finitely many
internal states, with changes of states occuring by arrival of other entities
described by a birth-death process.


title: Quantum reflection of bright matter-wave solitons

abstract:
  We propose the use of bright matter-wave solitons formed from Bose-Einstein
condensates with attractive interactions to probe and study quantum reflection
from a solid surface at normal incidence. We demonstrate that the presence of
attractive interatomic interactions leads to a number of advantages for the
study of quantum reflection. The absence of dispersion as the soliton
propagates allows precise control of the velocity normal to the surface and for
much lower velocities to be achieved. Numerical modelling shows that the
robust, self-trapped nature of bright solitons leads to a clean reflection from
the surface, limiting the disruption of the density profile and permitting
accurate measurements of the reflection probability.


title:
Estimating the entropy of binary time series: Methodology, some theory
  and a simulation study

abstract:
  Partly motivated by entropy-estimation problems in neuroscience, we present a
detailed and extensive comparison between some of the most popular and
effective entropy estimation methods used in practice: The plug-in method, four
different estimators based on the Lempel-Ziv (LZ) family of data compression
algorithms, an estimator based on the Context-Tree Weighting (CTW) method, and
the renewal entropy estimator.
  **Methodology. Three new entropy estimators are introduced. For two of the
four LZ-based estimators, a bootstrap procedure is described for evaluating
their standard error, and a practical rule of thumb is heuristically derived
for selecting the values of their parameters. ** Theory. We prove that, unlike
their earlier versions, the two new LZ-based estimators are consistent for
every finite-valued, stationary and ergodic process. An effective method is
derived for the accurate approximation of the entropy rate of a finite-state
HMM with known distribution. Heuristic calculations are presented and
approximate formulas are derived for evaluating the bias and the standard error
of each estimator. ** Simulation. All estimators are applied to a wide range of
data generated by numerous different processes with varying degrees of
dependence and memory. Some conclusions drawn from these experiments include:
(i) For all estimators considered, the main source of error is the bias. (ii)
The CTW method is repeatedly and consistently seen to provide the most accurate
results. (iii) The performance of the LZ-based estimators is often comparable
to that of the plug-in method. (iv) The main drawback of the plug-in method is
its computational inefficiency.


title: Collisional energy loss of a fast heavy quark in a quark-gluon plasma

abstract:
  We discuss the average collisional energy loss dE/dx of a heavy quark
crossing a quark-gluon plasma, in the limit of high quark energy E >> M^2/T,
where M is the quark mass and T >> M is the plasma temperature. In the fixed
coupling approximation, at leading order dE/dx \propto \alpha_s^2, with a
coefficient which is logarithmically enhanced. The soft logarithm arising from
t-channel scattering off thermal partons is well-known, but a collinear
logarithm from u-channel exchange had previously been overlooked. We also
determine the constant beyond those leading logarithms. We then generalize our
calculation of dE/dx to the case of running coupling. We estimate the remaining
theoretical uncertainty of dE/dx, which turns out to be quite large under RHIC
conditions. Finally, we point out an approximate relation between dE/dx and the
QCD Debye mass, from which we derive an upper bound to dE/dx for all quark
energies.


title: Construction of Reversible Lattice Molecular Automata

abstract:
  Several cellular automata (CA) models have been developed to simulate
self-organization of multiple levels of structures. However, they do not obey
microscopic reversibility and conservation laws. In this paper, we describe the
construction of a reversible lattice molecular automata (RLMA) model, which
simulates molecular interaction and self-organization of higher-order
structures. The model's strict reversibility entails physically relevant
conservation laws, and thus opens a way to precise application and validation
of the methods from statistical physics in studying the necessary conditions
for such multiple levels of self-organization.


title: Anisotropic scattering of Bogoliubov excitations

abstract:
  We consider elementary excitations of an interacting Bose-Einstein condensate
in the mean-field framework. As a building block for understanding the dynamics
of systems comprising interaction and disorder, we study the scattering of
Bogoliubov excitations by a single external impurity potential. A numerical
integration of the Gross-Pitaevskii equation shows that the single-scattering
amplitude has a marked angular anisotropy. By a saddle-point expansion of the
hydrodynamic mean-field energy functional, we derive the relevant scattering
amplitude including the crossover from sound-like to particle-like excitations.
The very different scattering properties of these limiting cases are smoothly
connected by an angular envelope function with a well-defined node of vanishing
scattering amplitude. We find that the overall scattering is most efficient at
the crossover from phonon-like to particle-like Bogoliubov excitations.


title:
Intersection local times of fractional Brownian motions with $H\in(0,1)$
  as generalized white noise functionals

abstract:
  In $\R^d$, for any dimension $d\geq 1$, expansions of self-intersection local
times of fractional Brownian motions with arbitrary Hurst coefficients in
$(0,1)$ are presented. The expansions are in terms of Wick powers of white
noises (corresponding to multiple Wiener integrals), being well-defined in the
sense of generalized white noise functionals.


title:
Two qubit conditional quantum logic operation in a single self-assembled
  quantum dot

abstract:
  The four-level exciton/biexciton system of a single semiconductor quantum dot
acts as a two qubit register. We experimentally demonstrate an
exciton-biexciton Rabi rotation conditional on the initial exciton spin in a
single InGaAs/GaAs dot. This forms the basis of an optically gated two-qubit
controlled-rotation (CROT) quantum logic operation where an arbitrary exciton
spin is selected as the target qubit using the polarization of the control
laser.


title: Non-abelian extensions of minimal rotations

abstract:
  We consider continuous extensions of minimal rotations on a locally connected
compact group X by arbitrary locally compact Lie groups and prove regularity
(i.e. the existence of orbit closures which project onto the whole basis X) in
certain special situations beyond the already known nilpotent case. We further
discuss an open question on cocycles acting on homogeneous spaces which seems
to be the missing key for a general regularity theorem.


title:
Intracule densities in the strong-interaction limit of density
  functional theory

abstract:
  The correlation energy in density functional theory can be expressed exactly
in terms of the change in the probability of finding two electrons at a given
distance $r_{12}$ (intracule density) when the electron-electron interaction is
multiplied by a real parameter $\lambda$ varying between 0 (Kohn-Sham system)
and 1 (physical system). In this process, usually called adiabatic connection,
the one-electron density is (ideally) kept fixed by a suitable local one-body
potential. While an accurate intracule density of the physical system can only
be obtained from expensive wavefunction-based calculations, being able to
construct good models starting from Kohn-Sham ingredients would highly improve
the accuracy of density functional calculations. To this purpose, we
investigate the intracule density in the $\lambda\to\infty$ limit of the
adiabatic connection. This strong-interaction limit of density functional
theory turns out to be, like the opposite non-interacting Kohn-Sham limit,
mathematically simple and can be entirely constructed from the knowledge of the
one-electron density. We develop here the theoretical framework and, using
accurate correlated one-electron densities, we calculate the intracule
densities in the strong interaction limit for few atoms. Comparison of our
results with the corresponding Kohn-Sham and physical quantities provides
useful hints for building approximate intracule densities along the adiabatic
connection of density functional theory.


title: On additive doubling and energy

abstract:
  We show that if A is a set having small subtractive doubling in an abelian
group, that is |A-A|< K|A|, then there is a polynomially large subset B of A-A
so that the additive energy of B is large than (1/K)^{1 - \epsilon) where
epsilon is a positive, universal exponent. (1/37 seems to suffice.)


title:
The first cohomology of the mapping class group with coefficients in
  algebraic functions on the SL(2, C) moduli space

abstract:
  Consider a compact surface of genus at least two. We prove that the first
cohomology group of the mapping class group with coefficients in the space of
algebraic functions on the SL(2, C) moduli space vanishes.


title: Support theorems for the Radon transform and Cram\'er-Wold theorems

abstract:
  This article presents extensions of the Cram{\'e}r-Wold theorem to measures
that may have infinite mass near the origin. Corresponding results for
sequences of measures are presented together with examples showing that the
assumptions imposed are sharp. The extensions build on a number of results and
methods concerned with injectivity properties of the Radon transform. Using a
few tools from distribution theory and Fourier analysis we show that the
presented injectivity results for the Radon transform lead to Cram{\'e}r-Wold
type results for measures. One purpose of this article is to contribute to
making known to probabilists interesting results for the Radon transform that
have been developed essentially during the 1980ies and 1990ies.


title: Absorption cross section of RN and SdS extremal black hole

abstract:
  The nature of scalar wave functions near the horizon of Reissner Nordstrom
(RN) extremal and Schwarzschild-de Sitter (SdS) extremal black holes are found
using WKB approximation and the effect of reflection of waves from the horizon.
The absorption cross section $\sigma_{abs}$ when RN extremal and SdS extremal
black holes placed in a Klein-Gordon field is calculated.


title:
Evolutionary models of short-period soft X-ray transients: comparison
  with observations

abstract:
  We consider evolutionary models for the population of short-period (<10 hr)
low-mass black-hole binaries (LMBHBs) and compare them with observations of
soft X-ray transients (SXTs). We show that assuming strongly reduced magnetic
braking (as suggested by us before for low-mass semidetached binaries) the
calculated masses and effective temperatures of secondaries are encouragingly
close to the observed masses and effective temperatures (as inferred from their
spectra) of donor stars in short-period LMBHBs. Theoretical mass-transfer rates
in SXTs are consistent with the observed ones if one assumes that accretion
discs in these systems are truncated (``leaky''). We find that the population
of short-period SXTs is formed mainly by systems which had unevolved or
slightly evolved main-sequence donors ($M_2 \lesssim 1.2M_\odot$) with a
hydrogen abundance in the center $X_c > 0.35$ at the Roche-lobe overflow
(RLOF). Longer period (0.5 - 1) day) SXTs might descend from systems with
initial donor masses of about 1 $M_\odot$ and $X_c < 0.35$. Thus, one can
explain the origin of short period LMBHB without invoking donors with cores
almost totally depleted of hydrogen. Our models suggest that, unless the
currently accepted empirical estimates of mass-loss rates by winds for massive
O-stars and Wolf-Rayet stars are significantly over-evaluated, a very high
efficiency of common-envelope ejection is necessary to form short-period
LMBHBs.


title:
Geometric analysis of Lorentzian distance function on spacelike
  hypersurfaces

abstract:
  Some analysis on the Lorentzian distance in a spacetime with controlled
sectional (or Ricci) curvatures is done. In particular, we focus on the study
of the restriction of such distance to a spacelike hypersurface satisfying the
Omori-Yau maximum principle. As a consequence, and under appropriate hypotheses
on the (sectional or Ricci) curvatures of the ambient spacetime, we obtain
sharp estimates for the mean curvature of those hypersurfaces. Moreover, we
also give a suficient condition for its hyperbolicity.


title: Unitary super perfect numbers

abstract: We shall show that 9, 165 are all of the odd unitary super perfect numbers.


title:
Superscaling and Charge-Changing Neutrino Scattering from Nuclei in the
  $\boldsymbol \Delta$-Region beyond the Relativistic Fermi Gas Model

abstract:
  The superscaling analysis using the scaling function obtained within the
coherent density fluctuation model is extended to calculate charge-changing
neutrino and antineutrino scattering on $^{12}$C at energies from 1 to 2 GeV
not only in the quasielastic but also in the delta excitation region. The
results are compared with those obtained using the scaling functions from the
relativistic Fermi gas model and from the superscaling analysis of inclusive
scattering of electrons from nuclei.


title: Infrared-modified gravities and massive gravitons

abstract:
  We review some theoretical and phenomenological aspects of massive gravities
in 4 dimensions. We start from the Fierz--Pauli theory with Lorentz-invariant
mass terms and then proceed to Lorentz-violating masses. Unlike the former
theory, some models with Lorentz-violation have no pathologies in the spectrum
in flat and nearly flat backgrounds and lead to interesting phenomenology.


title: Binary Formation in Star-Forming Clouds with Various Metallicities

abstract:
  Cloud evolution for various metallicities is investigated by
three-dimensional nested grid simulations, in which the initial ratio of
rotational to gravitational energy of the host cloud \beta_0 (=10^-1 - 10^-6)
and cloud metallicity Z (=0 - Z_\odot) are parameters. Starting from a central
number density of n = 10^4 cm^-3, cloud evolution for 48 models is calculated
until the protostar is formed (n \simeq 10^23 cm^-3) or fragmentation occurs.
The fragmentation condition depends both on the initial rotational energy and
cloud metallicity. Cloud rotation promotes fragmentation, while fragmentation
tends to be suppressed in clouds with higher metallicity. Fragmentation occurs
when \beta_0 > 10^-3 in clouds with solar metallicity, while fragmentation
occurs when \beta_0 > 10^-5 in the primordial gas cloud. Clouds with lower
metallicity have larger probability of fragmentation, which indicates that the
binary frequency is a decreasing function of cloud metallicity. Thus, the
binary frequency at the early universe (or lower metallicity environment) is
higher than at present day (or higher metallicity environment). In addition,
binary stars born from low-metallicity clouds have shorter orbital periods than
those from high-metallicity clouds. These trends are explained in terms of the
thermal history of the collapsing cloud.


title: Optimal experimental design and some related control problems

abstract:
  This paper traces the strong relations between experimental design and
control, such as the use of optimal inputs to obtain precise parameter
estimation in dynamical systems and the introduction of suitably designed
perturbations in adaptive control. The mathematical background of optimal
experimental design is briefly presented, and the role of experimental design
in the asymptotic properties of estimators is emphasized. Although most of the
paper concerns parametric models, some results are also presented for
statistical learning and prediction with nonparametric models.


title:
Asymptotic behaviour of a family of gradient algorithms in R^d and
  Hilbert spaces

abstract:
  The asymptotic behaviour of a family of gradient algorithms (including the
methods of steepest descent and minimum residues) for the optimisation of
bounded quadratic operators in R^d and Hilbert spaces is analyzed. The results
obtained generalize those of Akaike (1959) in several directions. First, all
algorithms in the family are shown to have the same asymptotic behaviour
(convergence to a two-point attractor), which implies in particular that they
have similar asymptotic convergence rates. Second, the analysis also covers the
Hilbert space case. A detailed analysis of the stability property of the
attractor is provided.


title:
Laterally defined freely suspended quantum dots in GaAs/AlGaAs
  heterostructures

abstract:
  Free standing beams containing a two-dimensional electron system are shaped
from a GaAs/AlGaAs heterostructure. Quantum point contacts and (double) quantum
dots are laterally defined using metal top gates. We investigate the electronic
properties of these nanostructures by transport spectroscopy. Tunable localized
electron states in freely suspended nanostructures are a promising tool to
investigate the electron-phonon-interaction.


title:
Demonstration of Ultra Low Dissipation Optomechanical Resonators on a
  Chip

abstract:
  Cavity-enhanced radiation-pressure coupling of optical and mechanical degrees
of freedom gives rise to a range of optomechanical phenomena, in particular
providing a route to the quantum regime of mesoscopic mechanical oscillators. A
prime challenge in cavity optomechanics has however been to realize systems
which simultaneously maximize optical finesse and mechanical quality. Here we
demonstrate for the first time independent control over both mechanical and
optical degree of freedom within one and the same on-chip resonator. The first
direct observation of mechanical normal mode coupling in a micromechanical
system allows for a quantitative understanding of mechanical dissipation.
Subsequent optimization of the resonator geometry enables intrinsic material
loss limited mechanical Q-factors, rivalling the best values reported in the
high MHz frequency range, while simultaneously preserving the resonators'
ultra-high optical finesse. Besides manifesting a complete understanding of
mechanical dissipation in microresonator based optomechanical systems, our
results provide an ideal setting for cavity optomechanics.


title:
Local structure in Ag$_3$[Co(CN)$_6$]: Colossal thermal expansion, rigid
  unit modes and argentophilic interactions

abstract:
  Local structure in the colossal thermal expansion material Ag$_3$[Co(CN)$_6$]
is studied here using a combination of neutron total scattering and reverse
Monte Carlo (RMC) analysis. We show that the large thermal variations in cell
dimensions occur with minimal distortion of the [Co(CN)$_6$] coordination
polyhedra, but involve significant flexing of the Co--CN--Ag--NC--Co linkages.
We find real-space evidence in our RMC configurations for the importance of
low-energy rigid unit modes (RUMs), particularly at temperatures below 150 K.
Using a reciprocal-space analysis we present the phonon density of states at
300 K and show that the lowest-frequency region is dominated by RUMs and
related modes. We also show that thermal variation in the energies of Ag$...$Ag
interactions is evident in both the Ag partial pair distribution function and
in the Ag partial phonon density of states. These findings are discussed in
relation to the thermodynamic properties of the material.


title: N=4 mechanics, WDVV equations and roots

abstract:
  N=4 superconformal multi-particle quantum mechanics on the real line is
governed by two prepotentials, U and F, which obey a system of partial
differential equations linear in U and generalizing the
Witten-Dijkgraaf-Verlinde-Verlinde (WDVV) equation for F. Putting U=0 yields a
class of models (with zero central charge) which are encoded by the finite
Coxeter root systems. We extend these WDVV solutions F in two ways: the A_n
system is deformed n-parametrically to the edge set of a general orthocentric
n-simplex, and the BCF-type systems form one-parameter families. A
classification strategy is proposed. A nonzero central charge requires turning
on U in a given F background, which we show is outside of reach of the standard
root-system ansatz for indecomposable systems of more than three particles. In
the three-body case, however, this ansatz can be generalized to establish a
series of nontrivial models based on the dihedral groups I_2(p), which are
permutation symmetric if 3 divides p. We explicitly present their full
prepotentials.


title: CFBDS J005910.90-011401.3: reaching the T-Y Brown Dwarf transition?

abstract:
  We report the discovery of CFBDS J005910.90-011401.3 (hereafter CFBDS0059),
the coolest brown dwarf identified to date. We found CFBDS0059 using i' and z'
images from the Canada-France-Hawaii Telescope (CFHT), and present optical and
near-infrared photometry, Keck laser guide star adaptive optics imaging, and a
complete near-infrared spectrum, from 1.0 to 2.2 $\mu$m. A side to side
comparison of the near-infrared spectra of CFBDS0059 and ULAS
J003402.77-005206.7 (hereafter ULAS0034), previously the coolest known brown
dwarf, indicates that CFBDS0059 is ~50+/-15K cooler. We estimate a temperature
of Teff ~ 620K and gravity of log g ~ 4.75. Evolutionary models translate these
parameters into an age of 1-5 Gyr and a mass of 15-30 M_Jup. We estimate a
photometric distance of ~13pc, which puts CFBDS0059 within easy reach of
accurate parallax measurements. Its large proper motion suggests membership in
the older population of the thin disk. The spectra of both CFBDS0059 and ULAS
J0034 shows probable absorption by a wide ammonia band on the blue side of the
$H$-band flux peak. If, as we expect, that feature deepens further for still
lower effective temperatures, its appearance will become a natural breakpoint
for the transition between the T spectral class and the new Y spectral type.
CFBDS0059 and ULAS J0034 would then be the first Y0 dwarfs.


title: On perturbations of continuous structures

abstract:
  We give a general framework for the treatment of perturbations of types and
structures in continuous logic, allowing to specify which parts of the logic
may be perturbed. We prove that separable, elementarily equivalent structures
which are approximately $\aleph_0$-saturated up to arbitrarily small
perturbations are isomorphic up to arbitrarily small perturbations (where the
notion of perturbation is part of the data). As a corollary, we obtain a
Ryll-Nardzewski style characterisation of complete theories all of whose
separable models are isomorphic up to arbitrarily small perturbations.


title:
Two phase partially miscible flow and transport modeling in porous
  media: application to gas migration in a nuclear waste repository

abstract:
  We derive a compositional compressible two-phase, liquid and gas, flow model
for numerical simulations of hydrogen migration in deep geological repository
for radioactive waste. This model includes capillary effects and the gas high
diffusivity. Moreover, it is written in variables (total hydrogen mass density
and liquid pressure) chosen in order to be consistent with gas appearance or
disappearance. We discuss the well possedness of this model and give some
computational evidences of its adequacy to simulate gas generation in a water
saturated repository.


title: Low Complexity Sphere Decoding for Spatial Multiplexing MIMO

abstract:
  In this paper we present a novel method for decoding multiple input -
multiple output (MIMO) transmission, which combines sphere decoding (SD) and
zero forcing (ZF) techniques to provide near optimal low complexity and high
performance constant time modified sphere decoding algorithm. This algorithm
was designed especially for large number of transmit antennas, and allows
efficient implementation in hardware. We do this by limiting the number of
overall SD iterations. Moreover, we make sure that matrices with high condition
number are more likely to undergo SD.


title: Evidence for a string-net matter

abstract: Further experiments showed the incorrectness of proposed interpretation.


title:
Local probing of the field emission stability of vertically aligned
  multiwalled carbon nanotubes

abstract:
  Metallic cantilever in high vacuum atomic force microscope has been used as
anode for field emission experiments from densely packed vertically aligned
multi-walled carbon nanotubes. The high spatial resolution provided by the
scanning probe technique allowed precise setting of the tip-sample distance in
the submicron region. The dimension of the probe (curvature radius below 50nm)
allowed to measure current contribution from sample areas smaller than 1um^2.
The study of long-term stability evidenced that on these small areas the field
emission current remains stable (within 10% fluctuations) several hours (at
least up to 72 hours) at current intensities between 10-5A and 10-8A.
Improvement of the current stability has been observed after performing
long-time Joule heating conditioning to completely remove possible adsorbates
on the nanotubes.


title: The Nonequilibrium Nature of Culinary Evolution

abstract:
  Food is an essential part of civilization, with a scope that ranges from the
biological to the economic and cultural levels. Here we study the statistics of
ingredients and recipes taken from Brazilian, British, French, and Medieval
cookbooks. We find universal distributions with scale invariant behavior. We
propose a copy-mutate process to model culinary evolution that fits very well
our empirical data. We find a cultural founder effect produced by the
nonequilibrium dynamics of the model. Both the invariant and idiosyncratic
aspects of culture are accounted by our model, which may have applications in
other kinds of evolutionary processes.


title:
Tits geometry on ideal boundaries of Busemann non-positively curved
  space

abstract:
  Let $X$ be a non-compact proper Busemann space. We introduce a collection of
binary relations on its ideal boundaries generalizing comparison of Tits metric
with two key values $\pi$ and $\pi/2$. This allows to use properties of Tits
metric known for CAT(0)-space without metric itself.


title: Nonlocal instantons and solitons in string models

abstract:
  We study a class of nonlocal systems which can be described by a local scalar
field diffusing in an auxiliary radial dimension. As examples p-adic, open and
boundary string field theory are considered on Minkowski,
Friedmann-Robertson-Walker and Euclidean metric backgrounds. Starting from
distribution-like initial field configurations which are constant almost
everywhere, we construct exact and approximate nonlocal solutions. The
Euclidean p-adic lump is interpreted as a solitonic brane, and the Euclidean
kink of supersymmetric open string field theory as an instanton. Some relations
between solutions of different string theories are highlighted also thanks to a
reformulation of nonlocal systems as fixed points in a renormalization group
flow.


title: The nature of the intranight variability of radio-quiet quasars

abstract:
  We select a sample of 10 radio-quiet quasars with confirmed intranight
optical variability and with available X-ray data. We compare the variability
properties and the broad band spectral constraints to the predictions of
intranight variability by three models: (i) irradiation of an accretion disk by
a variable X-ray flux (ii) an accretion disk instability (iii) the presence of
a weak blazar component. We concluded that the third model, e.g. the blazar
component model, is the most promising if we adopt a cannonball model for the
jet variable emission. In this case, the probability of detecting the
intranight variability is within 20-80%, depending on the ratio of the disk to
the jet optical luminosity. Variable X-ray irradiation mechanism is also
possible but only under additional requirement: either the source should have a
very narrow Hbeta line or occasional extremely strong flares should appear at
very large disk radii.


title:
Multi-frequency spectral analysis of extragalactic radio sources in the
  33-GHz VSA catalogue: sources with flattening and upturn spectrum

abstract:
  We present an analysis of the spectral properties of the extragalactic radio
sources in the nearly-complete VSA sample at 33GHz. Data from different surveys
are used to study source spectra between 1.4 and 33GHz. We find that, in
general, spectra can not be well described by a single power law in the range
of frequencies considered. In particular, most of the VSA sources that are
steep between 1.4 and 5GHz, show a spectral flattening at \nu>5GHz. We identify
20 objects (19% of the sample) clearly characterized by an upturn spectrum,
i.e., a spectrum falling at low frequencies (\nu<5GHz) and inverted at higher
frequencies. Spectra with high-frequency flattening or upturn shape are
supposed to occur when the emission from the AGN compact core begins to
dominate over the component from extended lobes. This picture fits well with
the AGN unified scheme, for objects observed at intermediate viewing angles of
the AGN jet. Finally, we discuss implications that this class of sources can
have on future CMB observations at high resolution.


title:
Solutions of multi-component NLS models and spinor Bose-Einstein
  condensates

abstract:
  A three- and five-component nonlinear Schrodinger-type models, which describe
spinor Bose-Einstein condensates (BEC's) with hyperfine structures F=1 and F=2
respectively, are studied. These models for particular values of the coupling
constants are integrable by the inverse scattering method. They are related to
symmetric spaces of BD.I-type SO(2r+1)/(SO(2) x SO(2r-1)) for r=2 and r=3.
Using conveniently modified Zakharov-Shabat dressing procedure we obtain
different types of soliton solutions.


title: Cosmon Lumps and Horizonless Black Holes

abstract:
  We investigate non-linear, spherically symmetric solutions to the coupled
system of a quintessence field and Einstein gravity. In the presence of a
scalar potential, we find regular solutions that to an outside observer very
closely resemble Schwarzschild black holes. However, these cosmon lumps have
neither a horizon nor a central singularity. A stability analysis reveals that
our static solutions are dynamically unstable. It remains an open question
whether analogous stable solutions exist.


title: Detailed transport investigation of the magnetic anisotropy of (Ga,Mn)As

abstract:
  This paper discusses transport methods for the investigation of the (Ga,Mn)As
magnetic anisotropy. Typical magnetoresistance behaviour for different
anisotropy types is discussed, focusing on an in depth discussion of the
anisotropy fingerprint technique and extending it to layers with primarily
uniaxial magnetic anisotropy. We find that in all (Ga,Mn)As films studied,
three anisotropy components are always present. The primary biaxial along
([100] and [010]) along with both uniaxial components along the [110] and [010]
crystal directions which are often reported separately. Various fingerprints of
typical (Ga,Mn)As transport samples at 4 K are included to illustrate the
variation of the relative strength of these anisotropy terms. We further
investigate the temperature dependence of the magnetic anisotropy and the
domain wall nucleation energy with the help of the fingerprint method.


title:
Spinor Green function in higher-dimensional cosmic string space-time in
  the presence of magnetic flux

abstract:
  In this paper we investigate the vacuum polarization effects associated with
quantum fermionic charged fields in a generalized $(d+1)-$dimensional cosmic
string space-times considering the presence of a magnetic flux along the
string. In order to develop this analysis we calculate a general expression for
the respective Green function, valid for several different values of $d$, which
is expressed in terms of a bispinor associated with the square of the Dirac
operator. Adopting this result, we explicitly calculate the renormalized vacuum
expectation values of the energy-momentum tensors, $<T^A_B>_{Ren.}$, associated
with massless fields. Moreover, for specific values of the parameters which
codify the cosmic string and the fractional part of the ratio of the magnetic
flux by the quantum one, we were able to present in closed forms the bispinor
and the respective Green function for massive fields.


title:
Generating multi-chain configurations of an inhomogeneous melt from the
  knowledge of single-chain properties

abstract:
  Mean-field techniques provide a rather accurate description of single-chain
conformations in spatially inhomogeneous polymer systems containing interfaces
or surfaces. Intermolecular correlations, however, are not described by the
mean-field approach and information about the distribution of distance between
different molecules is lost. Based on the knowledge of the exact equilibrium
single-chain properties in contact with solid substrates, we generate
multi-chain configurations that serve as nearly equilibrated starting
configurations for molecular dynamics simulations by utilizing the packing
algorithm of Auhl and co-workers [J. Chem. Phys. 119, 12718 (2003)] for
spatially inhomogeneous systems, i.e., a thin polymer film confined between two
solid substrates. The single-chain conformations are packed into the thin film
conserving the single-chain properties and simultaneously minimizing local
fluctuations of the density. The extent to which enforcing the
near-incompressibility of a dense polymer liquid during the packing process is
able to re-establish intermolecular correlations is investigated by monitoring
intermolecular correlation functions and the structure function of density
fluctuations as a function of the distance from the confining solid substrates.


title: The puzzling MILAGRO hot spots

abstract:
  We discuss the reported detection by the MILAGRO experiment of localised hot
spots in the cosmic ray arrival distribution and the difficulty of interpreting
these observations. A model based on secondary neutron production in the
heliotail is shown to fail. An alternative model based on loss-cone leakage
through a magnetic trap from a local source region is proposed.


title:
Star Formation Near Photodissociation Regions: Detection of a Peculiar
  Protostar Near Ced 201

abstract:
  We present the detection and characterization of a peculiar low-mass
protostar (IRAS 22129+7000) located ~0.4 pc from Ced 201 Photodissociation
Region (PDR) and ~0.2 pc from the HH450 jet. The cold circumstellar envelope
surrounding the object has been mapped through its 1.2 mm dust continuum
emission with IRAM-30m/MAMBO. The deeply embedded protostar is clearly detected
with Spitzer/MIPS (70 um), IRS (20-35 um) and IRAC (4.5, 5.8, and 8 um) but
also in the K_s band (2.15 um). Given the large "near- and mid-IR excess" in
its spectral energy distribution, but large submillimeter-to-bolometric
luminosity ratio (~2%), IRAS 22129+7000 must be a transition Class 0/I source
and/or a multiple stellar system. Targeted observations of several molecular
lines from CO, 13CO, C18O, HCO+ and DCO+ have been obtained. The presence of a
collimated molecular outflow mapped with the CSO telescope in the CO J=3-2 line
suggests that the protostar/disk system is still accreting material from its
natal envelope. Indeed, optically thick line profiles from high density tracers
such as HCO+ J=1-0 show a red-shifted-absorption asymmetry reminiscent of
inward motions. We construct a preliminary physical model of the circumstellar
envelope (including radial density and temperature gradients, velocity field
and turbulence) that reproduces the observed line profiles and estimates the
ionization fraction. The presence of both mechanical and (non-ionizing)
FUV-radiative input makes the region an interesting case to study triggered
star formation.


title: Fordy-Kulish models and spinor Bose-Einstein condensates

abstract:
  A three-component nonlinear Schrodinger-type model which describes spinor
Bose-Einstein condensate (BEC) is considered. This model is integrable by the
inverse scattering method and using Zakharov-Shabat dressing method we obtain
three types of soliton solutions. The multi-component nonlinear Schrodinger
type models related to symmetric spaces C.I Sp(4)/U(2) is studied.


title: Holographic quantum computing

abstract:
  We propose that a single mesoscopic ensemble of trapped polar molecules can
support a "holographic quantum computer" with hundreds of qubits encoded in
collective excitations with definite spatial phase variations. Each phase
pattern is uniquely addressed by optical Raman processes with classical optical
fields, while one- and two-qubit gates are accomplished by selectively
transferring the individual qubit states to a stripline microwave cavity field
and a Cooper pair box where controllable two-level unitary dynamics is governed
by classical microwave fields.


title: On the determination of curvature and dynamical Dark Energy

abstract:
  Constraining simultaneously the Dark Energy(DE) equation of state and the
curvature of the Universe is difficult due to strong degeneracies. To
circumvent this problem when analyzing data it is usual to assume flatness to
constrain DE, or conversely, to assume that DE is a cosmological constant to
constrain curvature. In this paper, we quantify the impact of such assumptions
in view of future large surveys. We simulate future data for type Ia Supernovae
(SNIa), Cosmic Microwave Background (CMB) and Baryon Acoustic Oscillations
(BAO) for a large range of fiducial cosmologies allowing a small spatial
curvature. We take into account a possible time evolution of DE through a
parameterized equation of state : $w(a) = w_0 + (1-a) w_a$. We then fit the
simulated data with a wrong assumption on the curvature or on the DE
parameters. For a fiducial $\Lambda$CDM cosmology, if flatness is incorrectly
assumed in the fit and if the true curvature is within the ranges
$0.01<\Omega_k<0.03$ and $-0.07<\Omega_k<-0.01$, one will conclude erroneously
to the presence of an evolving DE, even with high statistics. On the other
hand, models with curvature and dynamical DE can be confused with a flat
$\Lambda$CDM model when the fit ignores a possible DE evolution. We find that,
in the future, with high statistics, such risks of confusion should be limited,
but they are still possible, and biases on the cosmological parameters might be
important. We conclude on recalling that, in the future, it will be mandatory
to perform some complete multi-probes analyses, leaving the DE parameters as
well as the curvature as free parameters.


title: Heavy Flavour Baryons in Hyper Central Model

abstract:
  Heavy flavor baryons containing single and double charm (beauty) quarks with
light flavor combinations are studied using the hyper central description of
the three-body problem. The confinement potential is assumed as hyper central
coulomb plus power potential with power index $\upsilon$. The ground state
masses of the heavy flavor, $J^P={1/2}^+$ and ${3/2}^+$ baryons are computed
for different power index, $ \nu$ starting from 0.5 to 2.0. The predicted
masses are found to attain a saturated value in each case of quark combinations
beyond the power index $\nu=1.0$.


title:
Turbulent transport and its effect on the dead zone in protoplanetary
  discs

abstract:
  Protostellar accretion discs have cool, dense midplanes where externally
originating ionisation sources such as X-rays or cosmic rays are unable to
penetrate. This suggests that for a wide range of radii, MHD turbulence can
only be sustained in the surface layers where the ionisation fraction is
sufficiently high. A dead zone is expected to exist near the midplane, such
that active accretion only occurs near the upper and lower disc surfaces.
Recent work, however, suggests that under suitable conditions the dead zone may
be enlivened by turbulent transport of ions from the surface layers into the
dense interior.
  In this paper we present a suite of simulations that examine where, and under
which conditions, a dead zone can be enlivened by turbulent mixing. We use
three-dimensional, multifluid shearing box MHD simulations, which include
vertical stratification, ionisation chemistry, ohmic resistivity, and
ionisation due to X-rays from the central protostar. We compare the results of
the MHD simulations with a simple reaction-diffusion model.
  The simulations show that in the absence of gas-phase heavy metals, such as
magnesium, turbulent mixing has essentially no effect on the dead zone. The
addition of a relatively low abundance of magnesium, however, increases the
recombination time and allows turbulent mixing of ions to enliven the dead zone
completely beyond a distance of 5 AU from the central star, for our particular
disc model. During the late stages of protoplanetary disc evolution, when small
grains have been depleted and the disc surface density has decreased below its
high initial value, the structure of the dead zone may be significantly altered
by the action of turbulent transport.


title: Gamma-distribution and wealth inequality

abstract:
  We discuss the equivalence between kinetic wealth-exchange models, in which
agents exchange wealth during trades, and mechanical models of particles,
exchanging energy during collisions. The universality of the underlying
dynamics is shown both through a variational approach based on the minimization
of the Boltzmann entropy and a complementary microscopic analysis of the
collision dynamics of molecules in a gas. In various relevant cases the
equilibrium distribution is the same for all these models, namely a
gamma-distribution with suitably defined temperature and number of dimensions.
This in turn allows one to quantify the inequalities observed in the wealth
distributions and suggests that their origin should be traced back to very
general underlying mechanisms: for instance, it follows that the smaller the
fraction of the relevant quantity (e.g. wealth or energy) that agents can
exchange during an interaction, the closer the corresponding equilibrium
distribution is to a fair distribution.


title: Chi-square simulation of the CIR process and the Heston model

abstract:
  The transition probability of a Cox-Ingersoll-Ross process can be represented
by a non-central chi-square density. First we prove a new representation for
the central chi-square density based on sums of powers of generalized Gaussian
random variables. Second we prove Marsaglia's polar method extends to this
distribution, providing a simple, exact, robust and efficient
acceptance-rejection method for generalized Gaussian sampling and thus central
chi-square sampling. Third we derive a simple, high-accuracy, robust and
efficient direct inversion method for generalized Gaussian sampling based on
the Beasley-Springer-Moro method. Indeed the accuracy of the approximation to
the inverse cumulative distribution function is to the tenth decimal place. We
then apply our methods to non-central chi-square variance sampling in the
Heston model. We focus on the case when the number of degrees of freedom is
small and the zero boundary is attracting and attainable, typical in foreign
exchange markets. Using the additivity property of the chi-square distribution,
our methods apply in all parameter regimes.

categories: q-fin.CP math.NA math.PR math.ST q-fin.PR stat.TH


title: Cycle Equivalence of Graph Dynamical Systems

abstract:
  Graph dynamical systems (GDSs) can be used to describe a wide range of
distributed, nonlinear phenomena. In this paper we characterize cycle
equivalence of a class of finite GDSs called sequential dynamical systems SDSs.
In general, two finite GDSs are cycle equivalent if their periodic orbits are
isomorphic as directed graphs. Sequential dynamical systems may be thought of
as generalized cellular automata, and use an update order to construct the
dynamical system map.
  The main result of this paper is a characterization of cycle equivalence in
terms of shifts and reflections of the SDS update order. We construct two
graphs C(Y) and D(Y) whose components describe update orders that give rise to
cycle equivalent SDSs. The number of components in C(Y) and D(Y) is an upper
bound for the number of cycle equivalence classes one can obtain, and we
enumerate these quantities through a recursion relation for several graph
classes. The components of these graphs encode dynamical neutrality, the
component sizes represent periodic orbit structural stability, and the number
of components can be viewed as a system complexity measure.


title:
Nonlinear electromagnetic response of graphene: Frequency multiplication
  and the self-consistent-field effects

abstract:
  Graphene is a recently discovered carbon based material with unique physical
properties. This is a monolayer of graphite, and the two-dimensional electrons
and holes in it are described by the effective Dirac equation with a vanishing
effective mass. As a consequence, electromagnetic response of graphene is
predicted to be strongly non-linear. We develop a quasi-classical kinetic
theory of the non-linear electromagnetic response of graphene, taking into
account the self-consistent-field effects. Response of the system to both
harmonic and pulse excitation is considered. The frequency multiplication
effect, resulting from the non-linearity of the electromagnetic response, is
studied under realistic experimental conditions. The frequency up-conversion
efficiency is analysed as a function of the applied electric field and
parameters of the samples. Possible applications of graphene in terahertz
electronics are discussed.


title: Semigroup cohomology as a derived functor

abstract:
  In this work we construct an extension for the category of 0-modules by
analogy with [H.-J. Baues and G. Wirshing, Cohomology of small categories, J.
Pure Appl. Algebra, 38(1985), 187-211]. The 0-cohomology functor becomes a
derived functor in the extended category. As an application of this
construction we calculate the cohomological dimension of so-called 0-free
monoids.


title:
Design criteria for multi-layered scintillating fibre arrays with
  inclined columns

abstract:
  Multi-layered scintillating fibre arrays read-out are commonly used as high
resolution charged particle hodoscopes. Fibres of a column along the
geometrical trajectory of incident particles are typically grouped to one pixel
of a multi-channel read-out device. In some applications the incident particles
will cross the detection plane with large angles w.r.t. the normal to the
layers. Then, the packing of the fibres needs to be adapted to the incident
particles and the columns need to be inclined. In this paper possible fibre
array geometries are shown, relevant design criteria for detectors are
discussed, and the effect of diverging particles incident on fibre arrays was
studied using a Monte Carlo simulation.


title: Unparticles and inflation

abstract:
  We study some of the roles for unparticles in an inflationary universe.
Unparticles by themselves are not appropriate for generating the primordial
perturbations since their power spectrum does not match what has been inferred
from observations. In fact, when the scaling dimension for the unparticles
exceeds three-halves, the unparticle power spectrum diverges. However, when a
unparticle couples to an ordinary inflaton particle, loop corrections can
produce a slight enhancement of the inflaton's power spectrum at longer
wavelengths. We examine these loop corrections from unparticles in some detail
to learn how they scale in the wavelength of a perturbation and how they depend
on the scaling dimension of the field.


title:
A characterization of Schur multipliers between character-automorphic
  Hardy spaces

abstract:
  We give a new characterization of character-automorphic Hardy spaces of order
2 and of their contractive multipliers in terms of de Branges Rovnyak spaces.
Keys tools in our arguments are analytic extension and a factorization result
for matrix-valued analytic functions due to Leech.


title: Distribution of Fluctuational Paths in Noise-Driven Systems

abstract:
  Dynamics of a system that performs a large fluctuation to a given state is
essentially deterministic: the distribution of fluctuational paths peaks
sharply at a certain optimal path along which the system is most likely to
move. For the general case of a system driven by colored Gaussian noise, we
provide a formulation of the variational problem for optimal paths. We also
consider the prehistory problem, which makes it possible to analyze the shape
of the distribution of fluctuational paths that arrive at a given state. We
obtain, and solve in the limiting case, a set of linear equations for the
characteristic width of this distribution.


title: A model for hand-over-hand motion of molecular motors

abstract:
  A simple flashing ratchet model in two dimensions is proposed to simulate the
hand-over-hand motion of two head molecular motors like kinesin. Extensive
Langevin simulations of the model are performed. Good qualitative agreement
with the expected behavior is observed. We discuss different regimes of motion
and efficiency depending of model parameters.


title: Optical spectropolarimetry with incomplete data sets

abstract:
  Linear spectropolarimetry is a ``photon-hungry'' observing technique,
requiring a specific sequence of observations to determine the Stokes Q and U
parameters. For dual-beam spectropolarimeters, the parameters can be ideally
determined using observations at N=2 retarder plate positions. The additional
polarization signal introduced by instrumental effects requires the redundancy
of N=4 observations to correct for these effects. We wish to determine if the
``instrumental signature corrections'', eQ and eU, are identical for
observations with dual-beam spectropolarimeters. For instances when
observations were acquired at N=3 retarder plate angles, we wish to determine
if the complete measurement of one Stokes parameter and the associated
instrumental signature correction can be used to determine the other Stokes
parameter. We constructed analytical and Monte Carlo models of a general
dual-beam spectropolarimeter to study the factors affecting the assumption
eQ=eU. We compared these models with VLT FORS1 spectropolarimetry. We find that
eQ-eU=0, with the variance around zero (\Delta(eQ-eU)) being directly related
to the signal-to-noise ratio of the observations. Observations of a polarized
standard star, over the period 2002-2007, show that the assumption of eQ-eU=0
is generally true, although the absolute values of eQ and eU vary between
observational epochs. Incomplete spectropolarimetry datasets can be analyzed
under the assumption that eQ=eU. This property of the analysis of
spectropolarimetry, with dual beam spectropolarimeters, can be used to assess
the quality of the reduction for complete data.


title: The H alpha Galaxy Survey. IV. Star formation in the local Universe

abstract:
  We present an analysis of the star formation properties of field galaxies
within the local volume out to a recession velocity limit of 3000 km/s. A
parent sample of 863 star-forming galaxies is used to calculate a B-band
luminosity function. This is then populated with star formation information
from a subsample of 327 galaxies, for which we have H alpha imaging, firstly by
calibrating a relationship between galaxy B-band luminosity and star formation
rate, and secondly by a Monte Carlo simulation of a representative sample of
galaxies, in which star formation information is randomly sampled from the
observed subset. The total star formation rate density of the local Universe is
found to be between 0.016 and 0.023 MSun/yr/cubic Mpc, with the uncertainties
being dominated by the internal extinction correction used in converting
measured H alpha fluxes to star formation rates. If our internally derived
B-band luminosity function is replaced by one from the Sloan Digital Sky Survey
blue sequence, the star formation rate densities are approx. 60% of the above
values. We also calculate the contribution to the total star formation rate
density from galaxies of different luminosities and Hubble T-types. The largest
contribution comes from bright galaxies with B absolute mag of approx. -20 mag,
and the total contribution from galaxies fainter than -15.5 mag is less than
10%. Almost 60% of the star formation rate density comes from galaxies of types
Sb, Sbc or Sc; 9% from galaxies earlier than Sb and 33% from galaxies later
than Sc. Finally, 75 - 80% of the total star formation in the local Universe is
shown to be occurring in disk regions, defined as being >1 kpc from the centres
of galaxies.


title: Water vapour masers in long-period variable stars. I. RX Boo and SV Peg

abstract:
  We wish to understand the reasons for the strong variability of H2O masers in
circumstellar shells of late-type stars. We monitored RX Boo and SV Peg in the
22-GHz maser line of water vapour with single-dish telescopes. The monitoring
period covered two decades for RX Boo (1987 -- 2007) and 12 years for SV Peg
(1990 -- 1995, 2000 -- 2007). In addition, maps were obtained of RX Boo with
the Very Large Array over several years. We find that most of the emission in
the circumstellar shell of RX Boo is located in an incomplete ring with an
inner radius of 91 mas (15 AU). A velocity gradient is found in a NW--SE
direction. The maser region can be modelled as a shell with a thickness of 22
AU, which is only partially filled. The gas crossing time is 16.5 years. The
ring-like structure and the velocity gradient remained stable for at least 11
years, while the maser line profiles varied strongly. This suggests that the
spatial asymmetry is not accidental, so that either the mass loss process or
the maser excitation conditions in RX Boo are not spherically symmetric. The
strong variability of the maser spectral features is mainly due to incoherent
intensity fluctuations of maser emission spots, which have lifetimes of the
order of 1 year. We found no correlation between the optical and the maser
variability in either star. The variability properties of the SV Peg masers do
not differ substantially from those of RX Boo. There were fewer spectral
features present, and the range of variations was narrower. The maser was
active on the >10-Jy level only 1990 -- 1992 and 2006/2007. At other times the
maser was either absent (<1 Jy) or barely detectable.


title: Effective potential and vacuum stability

abstract:
  By following previous work on this subject, we investigate the issue of the
instability of the electroweak vacuum against the top loop corrections by
performing an accurate analysis of a Higgs-Yukawa model. We find that, when the
physical cutoff is properly implemented in the theory, the potential does not
exhibit any instability. Moreover, contrary to recent claims, we show that this
instability cannot be understood in terms of the very insightful work of Wu and
Weinberg on the non-convexity of the one-loop effective potential of a scalar
theory. Some of the theoretical and phenomenological consequences of our
results are briefly discussed.


title:
Correlation of the scattering and dispersion events in the Crab Nebula
  pulsar

abstract:
  In separate series of observations of the Crab pulsar, pulse broadening due
to scattering was measured at 111 MHz, and variations of dispersion due to
pulse delay were measured at higher radio frequencies. In a remarkable event
lasting 200 days a large increase occurred in both parameters and with similar
time signatures. The increases in scattering and dispersion measure observed
over the 200 days MJD 53950 - 54150 are attributable to the effects of an
ionised cloud or filament crossing the line of sight. The cloud would be $10^11
- 10^12 m across, with electron density 10^3 - 10^4 cm^-3. The increased
scattering might originate within the cloud itself, or the moving filament
might induce turbulence in a separate higher density cloud in the line of
sight.


title: On the Brauer monoid for finite fields

abstract:
  The Brauer monoid is studied by the notion of 0-cohomology. We investigate
the impact of invertible elements of modifications on the structure of the
Brauer monoid, especially for finite fields.


title:
Giant non-adiabatic effects in layer metals: Raman spectra of
  intercalated graphite explained

abstract:
  The occurrence of non-adiabatic effects in the vibrational properties of
metals have been predicted since the 60's, but hardly confirmed experimentally.
We report the first fully \emph{ab initio} calculations of non-adiabatic
frequencies of a number of layer and conventional metals. We suggest that
non-adiabatic effects can be a feature of the vibrational Raman spectra of any
bulk metal, and show that they are spectacularly large (up to 30% of the phonon
frequencies) in the case of layer metals, such as superconducting $MgB_2$,
$CaC_6$ and other graphite intercalated compounds. We develop a framework
capable to estimate the electron momentum-relaxation time of a given system,
and thus its degree of non-adiabaticity, in terms of the experimentally
observed frequencies and linewidths.


title:
Numerical Relativity meets Data Analysis: Spinning Binary Black Hole
  Case

abstract:
  We present a study of the gravitational waveforms from a series of spinning,
equal-mass black hole binaries focusing on the harmonic content of the waves
and the contribution of the individual harmonics to the signal-to-noise ratio.
The gravitational waves were produced from two series of evolutions with black
holes of initial spins equal in magnitude and anti-aligned with each other. In
one series the magnitude of the spin is varied; while in the second, the
initial angle between the black-hole spins and the orbital angular momentum
varies. We also conduct a preliminary investigation into using these waveforms
as templates for detecting spinning binary black holes. Since these runs are
relativity short, containing about two to three orbits, merger and ringdown, we
limit our study to systems of total mass greater than 50 solar masses. This
choice ensures that our waveforms are present in the ground-based detector band
without needing addition gravitational wave cycles. We find that while the mode
contribution to the signal-to-noise ratio varies with the initial angle, the
total mass of the system caused greater variations in the match.


title: The Sato Grassmannian and the CH hierarchy

abstract:
  We discuss how the Camassa-Holm hierarchy can be framed within the geometry
of the Sato Grassmannian.


title:
Hopping conduction in strongly insulating states of a diffusive bent
  quantum Hall junction

abstract:
  Transport studies of a bent quantum Hall junction at integer filling factors
show strongly insulating states at higher fields. In this paper we analyze the
strongly insulating behavior as a function of temperature T and dc bias V, in
order to classify the localization mechanisms responsible for the insulating
state. The temperature dependence suggests a crossover from activated
nearest-neighbor hopping at higher T to variable-range hopping conduction at
lower T. The base temperature electric field dependence is consistent with 1D
variable-range hopping conduction. We observe almost identical behavior at
filling factors 1 and 2, and discuss how the bent quantum Hall junction
conductance appears to be independent of the bulk spin state. Various models of
1D variable-range hopping which either include or ignore interactions are
compared, all of which are consistent with the basic model of disorder coupled
counter-propagating quantum Hall edges.


title: Affleck-Dine condensate, late thermalization and the gravitino problem

abstract:
  In this clarifying note we discuss the late decay of an Affleck-Dine
condensate by providing a no-go theorem that attributes to conserved global
charges which are identified by the net particle number in fields which are
included in the flat direction(s). For a rotating condensate, this implies
that: (1) the net baryon/lepton number density stored in the condensate is
always conserved, and (2) the total particle number density in the condensate
cannot decrease. This reiterates that, irrespective of possible
non-perturbative particle production due to $D$-terms in a multiple flat
direction case, the prime decay mode of an Affleck-Dine condensate will be
perturbative as originally envisaged. As a result, cosmological consequences of
flat directions such as delayed thermalization as a novel solution to the
gravitino overproduction problem will remain virtually intact.


title: Automorphisms of wonderful varieties

abstract:
  Let G be a complex semisimple linear algebraic group, and X a wonderful
G-variety. We determine the connected automorphism group of X and we calculate
Luna's invariants of X under its action.


title: Uniformisation of foliations by curves

abstract:
  These are lecture notes for a course to be held. They provide a full
discussion of certain analytic aspects of the uniformisation theory of
(singular) holomorphic foliations by curves on compact Kaehler manifolds, with
emphasis on their consequences on positivity properties of the corresponding
canonical bundles.


title: The evolution of star clusters: The resolved-star approach

abstract:
  We present the first results of a new technique to detect, locate, and
characterize young dissolving star clusters. Using HST/ACS archival images of
the nearby galaxy IC2574, we performed stellar PSF photometry and selected the
most massive stars as our first test sample. We used a group-finding algorithm
on the selected massive stars to find cluster candidates. We then plot the
color-magnitude diagrams for each group, and use stellar evolutionary models to
estimate their age. So far, we found 79 groups with ages of up to about 100
Myr, displaying various sizes and densities.


title: Asymptotic analysis of a fluid model modulated by an $M/M/1$ queue

abstract:
  We analyze asymptotically a differential-difference equation, that arises in
a Markov-modulated fluid model. We use singular perturbation methods to analyze
the problem with appropriate scalings of the two state variables. In
particular, the ray method and asymptotic matching are used.


title: LDA+DMFT implemented with the pseudopotential plane-wave approach

abstract:
  We present a joint implementation of dynamical-mean-field theory (DMFT) with
the pseudopotential plane-wave approach, via Wannier functions, for the
determination of the electronic properties of strongly correlated materials.
The scheme uses, as input for the DMFT calculations, a tight-binding
Hamiltonian obtained from the plane-wave calculations by projecting onto
atomic-centered symmetry-constrained Wannier functions for the correlated
orbitals. We apply this scheme to two prototype systems: a paramagnetic
correlated metal, SrVO3, and a paramagnetic correlated system, V2O3, which
exhibits a metal-insulator transition. Comparison with available
Linear-Muffin-Tin-Orbital (LMTO) plus DMFT calculations demonstrate the
suitability of the joint DMFT pseudopotential-plane-wave approach to describe
the electronic properties of strongly correlated materials. This opens the way
to future developments using the pseudopotential-plane-wave DMFT approach to
address also total-energy properties, such as structural properties.


title: Krasinkiewicz spaces and parametric Krasinkiewicz maps

abstract:
  We say that a metrizable space $M$ is a Krasinkiewicz space if any map from a
metrizable compactum $X$ into $M$ can be approximated by Krasinkiewicz maps (a
map $g\colon X\to M$ is Krasinkiewicz provided every continuum in $X$ is either
contained in a fiber of $g$ or contains a component of a fiber of $g$). In this
paper we establish the following property of Krasinkiewicz spaces: Let $f\colon
X\to Y$ be a perfect map between metrizable spaces and $M$ a Krasinkiewicz
complete $ANR$-space. If $Y$ is a countable union of closed finite-dimensional
subsets, then the function space $C(X,M)$ with the source limitation topology
contains a dense $G_{\delta}$-subset of maps $g$ such that all restrictions
$g|f^{-1}(y)$, $y\in Y$, are Krasinkiewicz maps. The same conclusion remains
true if $M$ is homeomorphic to a closed convex subset of a Banach space and $X$
is a $C$-space.


title: Dislocation induced ac Josephson effect in high-T_c superconductors

abstract:
  A possible scenario for an ac Josephson effect initiated by the flow of
dislocations through a mechanically loaded but electrically unbiased
superconductor is proposed. The characteristic voltages due to the motion of
dislocations in loaded (under the applied stress of 10^7N/m^2) YBCO crystals
are estimated to be of the order of a few picovolts (which corresponds to the
Josephson frequency of 10 kHz).