title:
Maximum principle and convergence of fundamental solutions for the Ricci
  flow

abstract:
  In this paper we will prove a maximum principle for the solutions of linear
parabolic equation on complete non-compact manifolds with a time varying
metric. We will prove the convergence of the Neumann Green function of the
conjugate heat equation for the Ricci flow in $B_k\times (0,T)$ to the minimal
fundamental solution of the conjugate heat equation as $k\to\infty$. We will
prove the uniqueness of the fundamental solution under some exponential decay
assumption on the fundamental solution. We will also give a detail proof of the
convergence of the fundamental solutions of the conjugate heat equation for a
sequence of pointed Ricci flow $(M_k\times (-\alpha,0],x_k,g_k)$ to the
fundamental solution of the limit manifold as $k\to\infty$ which was used
without proof by Perelman in his proof of the pseudolocality theorem for Ricci
flow.


title: Phenomenology of turbulent dynamo growth and saturation

abstract:
  With a non local shell model of magnetohydrodynamic turbulence we investigate
numerically the turbulent dynamo action for low and high magnetic Prandtl
numbers ($Pm$). The results obtained in the kinematic regime and along the way
to dynamo saturation are understood in terms of a phenomenological approach
based on the local ($Pm\ll 1$) or non local ($Pm\gg 1$) nature of the energy
transfers. In both cases the magnetic energy grows at small scale and saturates
as an inverse `` cascade ''.


title:
Neutrinos and Lepton Flavour Violation in the Left-Right Twin Higgs
  Model

abstract:
  We analyse the lepton sector of the Left-Right Twin Higgs Model. This model
offers an alternative way to solve the "little hierarchy" problem of the
Standard Model. We show that one can achieve an effective see-saw to explain
the origin of neutrino masses and that this model can accommodate the observed
neutrino masses and mixings. We have also studied the lepton flavour violation
process l_1 -> l_2 \gamma and discussed how the experimental bound from these
branching ratios constrains the scale of symmetry breaking of this Twin Higgs
model.


title: Progress in kaon physics on the lattice

abstract:
  CKM-unitarity, direct and indirect CP-violation and the \Delta I=1/2 rule in
full lattice QCD are the focus of this talk. To this end I will discuss and
compare recent lattice results for leptonic, semi-leptonic and non-leptonic
decays of the kaon and neutral kaon mixing and I will motivate current best
estimates f_K/f_\pi=1.198(10), f_+^{K\pi}(0)=0.964(5) and \hat{B}_K=0.720(39).
Moreover new theoretical advances that will improve the quality of these
computations in the future will be discussed.


title:
Supersymmetric Dark Matter Candidates - The Lightest Neutralino, the
  Gravitino, and the Axino

abstract:
  In supersymmetric extensions of the Standard Model, the lightest neutralino,
the gravitino, and the axino can appear as the lightest supersymmetric particle
and as such provide a compelling explanation of the non-baryonic dark matter in
our Universe. For each of these dark matter candidates, I review the present
status of primordial production mechanisms, cosmological constraints, and
prospects of experimental identification.


title:
X-ray Resonant Scattering Study of the Order Parameters in Multiferroic
  TbMnO$_3$

abstract:
  We report on an extensive investigation of the multiferroic compound
TbMnO$_3$. Non-resonant x-ray magnetic scattering (NRXMS) revealed a dominant
$A$-type domain. The temperature dependence of the intensity and wavevector
associated with the incommensurate magnetic order was found to be in good
agreement with neutron scattering data. XRS experiments were performed in the
vicinity of the Mn $K$ and Tb $L_3$ edges in the high-temperature collinear
phase, the intermediate temperature cycloidal/ferroelectric phase, and the
low-temperature phase. In the collinear phase resonant $E1-E1$ satellites were
found at the Mn $K$ edge associated with $A$-type but also $F$-type peaks. The
azimuthal dependence of the $F$-type satellites (and their absence in the NRXMS
experiments) indicates that they are most likely non-magnetic in origin. We
suggest instead that they may be associated with an induced charge multipole.
At the Tb $L_3$ edge resonant $A$- and $F$-type satellites ($E1-E1$) were
observed in the collinear phase. These we attribute to a polarisation of the Tb
5$d$ states by the ordering of the Mn sublattice. In the
cycloidal/ferroelectric phase a new set of resonant satellites appear
corresponding to $C$-type order. These appear at the Tb $L_3$ edge only. In
addition to a dominant $E1-E1$ component in the $\sigma-\pi^\prime$ channel, a
weaker component is found in the pre-edge with $\sigma-\sigma^\prime$
polarization. Calculations of the XRS were performed using the $FDMNES$ code
showing that the unrotated $\sigma-\sigma^\prime$ component of the Tb $L_3$
$C$-type peaks appearing in the ferroelectric phase contains a contribution
from a multipole that is odd with respect to both space and time, known in
various contexts as the anapole.


title: The Price of Selfish Stackelberg Leadership in a Network Game

abstract:
  We study a class of games in which a finite number of agents each controls a
quantity of flow to be routed through a network, and are able to split their
own flow between multiple paths through the network. Recent work on this model
has contrasted the social cost of Nash equilibria with the best possible social
cost. Here we show that additional costs are incurred in situations where a
selfish ``leader'' agent allocates his flow, and then commits to that choice so
that other agents are compelled to minimise their own cost based on the first
agent's choice. We find that even in simple networks, the leader can often
improve his own cost at the expense of increased social cost. Focusing on the
2-player case, we give upper and lower bounds on the worst-case additional cost
incurred.


title: Functions of State for Spinor Gas in General Relativity

abstract:
  The energy momentum tensor of perfect fluid is a simplified but successful
model in astrophysics. In this paper, assuming the particles driven by gravity
and moving along geodesics, we derived the functions of state in detail. The
results show that, these functions have a little correction for the usual
thermodynamics. The new functions naturally satisfy the causal condition and
consist with relativity. For the self potentials of the particles we introduce
an extra function $W$, which acts like negative pressure and can be used to
describe dark matter. The results are helpful to understand the relation and
interaction between space-time and matter.


title: Quasistationary quaternionic Hamiltonians and complex stochastic maps

abstract:
  We show that the complex projections of time-dependent $\eta
$-quasianti-Hermitian quaternionic Hamiltonian dynamics are complex stochastic
dynamics in the space of complex quasi-Hermitian density matrices if and only
if a quasistationarity condition is fulfilled, i. e., if and only if $\eta $ is
an Hermitian positive time-independent complex operator. An example is also
discussed.


title: Optimal evaluation of single-molecule force spectroscopy experiments

abstract:
  The forced rupture of single chemical bonds under external load is addressed.
A general framework is put forward to optimally utilize the experimentally
observed rupture force data for estimating the parameters of a theoretical
model. As an application we explore to what extent a distinction between
several recently proposed models is feasible on the basis of realistic
experimental data sets.


title:
Finite-thickness effects in ground-state transitions of two-electron
  quantum dots

abstract:
  Using the exactly solvable excitation spectrum of two-electron quantum dots
with parabolic potential, we show that the inclusion of the vertical extension
of the quantum dot provides a consistent description of the experimental
findings of Nishi et al. [Phys.Rev.B75, 121301(R) (2007)]. We found that the
second singlet-triplet transition in the ground state is a vanishing function
of the lateral confinement in the three-dimensional case, while it always
persists in the two-dimensional case. We show that a slight decrease of the
lateral confinement leads to a formation of the Wigner molecule at low magnetic
fields.


title: Discovery of Quantum Hidden Variable

abstract:
  The first clue, in the theory of relativity, the 4-vector force acting on a
particle is orthogonal to the 4-vector velocity of the particle, this
orthogonality means that there is some difference between the orthogonality and
the usual statement: the Coulomb's force (or gravitational force) acts along
the line joining a couple of particles (in usual 3D space), so the direction of
4-vector Coulomb's force is carefully investigated, it is found that Maxwell's
equations can be derived from classical Coulomb's force and the orthogonality.
The second clue, a 4-vector force has 4 components, because of the
orthogonality of 4-vector force and 4-vector velocity, the number of
independent components of the 4-vector force reduces to 3, however we prove
that 4-vector Coulomb's force can merely provide 2 independent components, this
situation means that there is an undefined component accompanying the 4-vector
Coulomb's force, hinting that this missing undefined component is a hidden
variable. The third clue, the best way to study the hidden variable is to
establish a new concept: Z-space, in which the undefined component of 4-vector
Coulomb's force can be clearly defined as the hidden variable for the quantum
mechanics. At the last, the undefined component is regarded as a fluctuating
source that contributes to Lorentz force, so that the quantum wave equation can
be derived out in the ensemble space of particle motion from the relativistic
Newton's second law.


title:
Dynamical NNLO parton distributions and the perturbative stability of
  F_L(x,Q^2)

abstract:
  It is shown that the previously noted extreme perturbative NNLO/NLO
instability of the longitudinal structure function F_L(x,Q^2) is a mere
artefact of the commonly utilized `standard' gluon distributions. In particular
it is demonstrated that using the appropriate -- dynamically generated --
parton distributions at NLO and NNLO, F_L(x,Q^2) turns out to be perturbatively
rather stable already for Q^2 $\geq$ O(2-3 GeV^2).


title: Contributions to Random Energy Models

abstract:
  In this thesis, we consider several Random Energy Models. This includes
Derrida's Random Energy Model (REM) and Generalized Random Energy Model (GREM)
and a nonhierarchical version (BK-GREM) by Bolthausen and Kistler. The limiting
free energy in all these models along with Word GREM, a model proposed by us,
turn out to be a cute consequence of large deviation principle (LDP). This LDP
argument allows us to consider non-Gaussian driving distributions as well as
external field. We could also consider random trees as the underlying tree
structure in GREM. In all these models, as expected, limiting free energy is
not 'universal' unlike the SK model. However it is 'rate specific'.
Consideration of non-Gaussian driving distribution as well as different driving
distributions for the different levels of the underlying trees in GREM leads to
interesting phenomena. For example in REM, if the Hamiltonian is Binomial with
parameter $N$ and $p$ then the existence of phase transition depends on the
parameter $p$. More precisely, phase transition takes place only when
$p>{1/2}$. For another example, consider a 2 level GREM with exponential
driving distribution at the first level and Gaussian in the second with equal
weights at both the levels. Then even if the limiting ratio for the second
level particles, $p_2$ is 0.00001 (very small), the system reduces to a
Gaussian REM. On the other hand, if we consider a 2 level GREM with Gaussian
driving distribution at the first level and exponential in the second, the
system will never reduce to a Gaussian REM. In either case, the system will
never reduce to that of an exponential REM. etc.


title: Convexity in locally conformally flat manifolds with boundary

abstract:
  Given a closed subset $\La$ of the open unit ball $B_1\subset \real^n$, $n
\geq 3$, we will consider a complete Riemannian metric $g$ on $\bar{B_1}
\setminus \La$ of constant scalar curvature equal to $n(n-1)$ and conformally
related to the Euclidean metric. In this paper we prove that every closed
Euclidean ball $\bar{B} \subset B_1\setminus \La$ is convex with respect to the
metric $g$, assuming the mean curvature of the boundary $\partial B_1$ is
nonnegative with respect to the inward normal.


title:
Manifestation of a complex edge excitation structure in the fractional
  quantum Hall regime at high filling factors

abstract:
  We experimentally study equilibration across the sample edge at high
fractional filling factors 4/3, 5/3 under experimental conditions, which allow
us to obtain high imbalance conditions. We find a lack of the full
equilibration across the edge even in the flat-band situation, where no
potential barrier survives at the sample edge. We interpret this result as the
manifestation of complicated edge excitation structure at high fractional
filling factors 4/3, 5/3. Also, a mobility gap in the $\nu_c=1$ incompressible
strip is determined in normal and tilted magnetic fields.


title:
Energetics of thermal inactivation of excitonically-induced defect
  formation in rare-gas solids

abstract:
  Thermodynamic parameters of thermal inactivation of excitonically induced
defect formation in rare-gas solids have been obtained from the fitting of the
temperature dependences of defect formation rates, which were measured under
selective photoexcitation by synchrotron radiation.


title:
Angular momentum conservation in heavy ion collisions at very high
  energy

abstract:
  The effects of angular momentum conservation in peripheral heavy ion
collisions at very high energy are investigated. It is shown that the initial
angular momentum of the quark-gluon plasma should enhance the azimuthal
anisotropy of particle spectra (elliptic flow) with respect to the usual
picture where only the initial geometrical eccentricity of the nuclear overlap
region is responsible for the anisotropy. In hydrodynamical terms, the initial
angular momentum entails a non trivial dependence of the initial longitudinal
flow velocity on the transverse coordinates. This gives rise to a non-vanishing
vorticity in the equations of motion which enhances the expansion rate of the
supposedly created fluid compensating for the possible quenching effect of
viscosity. A distinctive signature of the vorticity in the plasma is the
generation of an average polarization of the emitted hadrons, for which we
provide analytical expressions. These phenomena might be better observed at
LHC, where the initial angular momentum density will be larger and where we
envisage an increase of the elliptic flow coefficient v_2 with respect to RHIC
energies.


title: Gauss-Codazzi Formalism to Braneworld Scenario within Brans-Dicke Theory

abstract:
  We apply the Gauss-Codacci formalism to brane worlds scenario within the
framework of Brans-Dicke gravity. The compactification is taken from six to
five dimensions in order to formalize brane-world models with hybrid
compactification in scalar-tensor theories.


title: Mesoscopic Coulomb Supersolid

abstract:
  When a few tens of charged particles are trapped in a spherical electrostatic
potential at low temperature they form concentric shells resembling atoms.
These ``artificial atoms'' can be easily controlled by varying the confinement
strength. We analyze such systems for the case that the particles are bosons
and find superfluid behavior which even persists in the solid state. This novel
state of matter is a mesoscopic supersolid.


title:
Influence of electronic correlations on the frequency-dependent hopping
  transport in Si:P

abstract:
  At low energy scales charge transport in the insulating Si:P is dominated by
activated hopping between the localized donor electron states. Thus,
theoretical models for a disordered system with electron-electron interaction
are appropriate to interpret the electric conductivity spectra. With a newly
developed technique we have measured the complex broadband microwave
conductivity of Si:P from 100 MHz to 5 GHz in a broad range of phosphorus
concentration $n/n_c$ from 0.56 to 0.95 relative to the critical value
$n_c=3.5\times 10^{18}$ cm$^{-3}$ corresponding to the metal-insulator
transition driven by doping. At our base temperature of $T =1.1$ K the samples
are in the zero-phonon regime where they show a super-linear frequency
dependence of the conductivity indicating the influence of the Coulomb gap in
the density of the impurity states. At higher doping $n\to n_c$, an abrupt drop
in the conductivity power law $\sig(\omega)\sim\omega^\alpha$ is observed. The
dielectric function $\eps$ increases upon doping following a power law in
($1-n/n_c$). Dynamic response at elevated temperatures has also been
investigated.


title: Bifurcations in the regularized Ericksen bar model

abstract:
  We consider the regularized Ericksen model of an elastic bar on an elastic
foundation on an interval with Dirichlet boundary conditions as a two-parameter
bifurcation problem. We explore, using local bifurcation analysis and
continuation methods, the structure of bifurcations from double zero
eigenvalues. Our results provide evidence in support of M\"uller's conjecture
\cite{Muller} concerning the symmetry of local minimizers of the associated
energy functional and describe in detail the structure of the primary branch
connections that occur in this problem. We give a reformulation of M\"uller's
conjecture and suggest two further conjectures based on the local analysis and
numerical observations. We conclude by analysing a ``loop'' structure that
characterizes $(k,3k)$ bifurcations.


title: The critical contact process in a randomly evolving environment dies out

abstract:
  Bezuidenhout and Grimmett proved that the critical contact process dies out.
Here, we generalize the result to the so called contact process in a random
evolving environment (CPREE), introduced by Erik Broman. This process is a
generalization of the contact process where the recovery rate can vary between
two values. The rate which it chooses is determined by a background process,
which evolves independently at different sites. As for the contact process, we
can similarly define a critical value in terms of survival for this process. In
this paper we prove that this definition is independent of how we start the
background process, that finite and infinite survival (meaning nontriviality of
the upper invariant measure) are equivalent and finally that the process dies
out at criticality.


title: Density waves and Cooper pairing on the honeycomb lattice

abstract:
  Motivated by the surge in research activities on graphene, we investigate
instabilities of electrons on the honeycomb lattice, interacting by onsite and
nearest-neighbor terms, using a renormalization group scheme. Near half
band-filling, critical minimal interaction strengths are required for
instabilities toward antiferromagnetic or charge-density wave order. Away from
half filling, f-wave triplet pairing and d+id singlet pairing instabilities are
found to emerge out of density-wave regimes.


title:
Influence of synaptic interaction on firing synchronization and spike
  death in excitatory neuronal networks

abstract:
  We investigated the influence of efficacy of synaptic interaction on firing
synchronization in excitatory neuronal networks. We found spike death
phenomena, namely, the state of neurons transits from limit cycle to fixed
point or transient state. The phenomena occur under the perturbation of
excitatory synaptic interaction that has a high efficacy. We showed that the
decrease of synaptic current results in spike death through depressing the
feedback of sodium ionic current. In the networks with spike death property the
degree of synchronization is lower and unsensitive to the heterogeneity of
neurons. The mechanism of the influence is that the transition of neuron state
disrupts the adjustment of the rhythm of neuron oscillation and prevents
further increase of firing synchronization.


title:
Who's talking first? Consensus or lack thereof in coevolving opinion
  formation models

abstract:
  We investigate different opinion formation models on adaptive network
topologies. Depending on the dynamical process, rewiring can either (i) lead to
the elimination of interactions between agents in different states, and
accelerate the convergence to a consensus state or break the network in
non-interacting groups or (ii) counter-intuitively, favor the existence of
diverse interacting groups for exponentially long times. The mean-field
analysis allows to elucidate the mechanisms at play. Strikingly, allowing the
interacting agents to bear more than one opinion at the same time drastically
changes the model's behavior and leads to fast consensus.


title: Inductive Methods and zero-sum free sequences

abstract: We obtain a decidability result for the Davenport constant.


title:
Study of Intrinsic Spin Hall Effect and Orbital Hall Effect in 4d- and
  5d- Transition Metals

abstract:
  We study the intrinsic spin Hall conductivity (SHC) in various
$5d$-transition metals (Ta, W, Re, Os, Ir, Pt, and Au) and 4d-transition metals
(Nb, Mo, Tc, Ru, Rh, Pd, and Ag) based on the Naval Research Laboratory
tight-binding model, which enables us to perform quantitatively reliable
analysis. In each metal, the obtained intrinsic SHC is independent of
resistivity in the low resistive regime ($\rho < 50 \mu\Omega\text{cm}$)
whereas it decreases in proportion to $\rho^{-2}$ in the high resistive regime.
In the low resistive regime, the SHC takes a large positive value in Pt and Pd,
both of which have approximately nine $d$-electrons per ion ($n_d=9$). On the
other hand, the SHC takes a large negative value in Ta, Nb, W, and Mo where
$n_d<5$. In transition metals, a conduction electron acquires the
trajectory-dependent phase factor that originates from the atomic wavefunction.
This phase factor, which is reminiscent of the Aharonov-Bohm phase, is the
origin of the SHC in paramagnetic metals and that of the anomalous Hall
conductivity in ferromagnetic metals. Furthermore, each transition metal shows
huge and positive $d$-orbital Hall conductivity (OHC), independently of the
strength of the spin-orbit interaction (SOI). Since the OHC is much larger than
the SHC, it will be possible to realize a {\it orbitronics device} made of
transition metals.


title:
Conversion of Dark matter axions to photons in magnetospheres of neutron
  stars

abstract:
  We propose a new method to detect observational appearance of Dark Matter
axions. The method utilizes observations of neutron stars (NSs) in radio. It is
based on the conversion of axions to photons in strong magnetic fields of NSs
(Primakoff effect). Whether the conversion takes place, the radio spectrum of
the object would have a very distinctive feature -- a narrow spike at a
frequency corresponding to the rest mass of the axion. For example, if the
coupling constant of the photon-axion interaction is $M=10^{10}$ GeV, the
density of Dark Matter axions is $\rho=10^{-24} {\rm g cm^{-3}}$, and the axion
mass is $5 {\rm \mu eV}$, then a flux from a strongly magnetized ($10^{14}$ G)
NS at the distance 300 pc from the Sun is expected to be about few tenths of
mJy at the frequency $\approx 1200$ MHz in the bandwidth $\approx 3$ MHz.
Close-by X-ray dim isolated neutron stars are proposed as good candidates to
look for such radio emission.


title:
An Asymptotic Formalism for Reconstructing Small Perturbations of
  Scatterers from Electric or Acoustic Far-Field Measurements

abstract:
  We consider the problem of determining the boundary perturbations of an
object from far-field electric or acoustic measurements. Assuming that the
unknown object boundary is a small perturbation of a circle, we develop a
linearized relation between the far-field data that result from fixed Dirichlet
boundary conditions, entering as parameters, and the shape of the object,
entering as variables. This relation is used to find the Fourier coefficients
of the perturbation of the shape and makes use of an expansion of the
Dirichlet-to-Neumann operator.


title: Magnetic monopoles in the high temperature phase of Yang-Mills theories

abstract:
  We investigate the properties of thermal abelian magnetic monopoles in the
high temperature phase of Yang--Mills theories, following a recent proposal for
their identification on lattice configurations. The study is done for SU(2)
pure gauge theory, for temperatures going up to about 10 times the deconfining
temperature and using the Maximal Abelian gauge to perform the abelian
projection. We find that the monopole density has a well defined continuum
limit. Its temperature dependence disagrees with a free particle gas prediction
and is instead well described by a $T^3/(\log (T/\Lambda))^\alpha$ behaviour in
all the explored range, with $\alpha \sim 2$ and $\Lambda \sim 100$ MeV. Also
the study of spatial correlations of thermal monopoles shows the presence of
non-trivial interactions among them. Finally, we discuss the gauge dependence
of our results, showing that it is significant and that, even within the
Maximal Abelian gauge, Gribov copy effects are important.


title:
Magnetic field structures of galaxies derived from analysis of Faraday
  rotation measures, and perspectives for the SKA

abstract:
  The forthcoming new-generation radio telescope SKA (Square Kilometre Array)
and its precursors will provide a rapidly growing number of polarized radio
sources. Our analysis aims on what can be learned from these sources concerning
the structure and evolution of magnetic fields of external galaxies.
Recognition of magnetic structures is possible from Faraday rotation measures
(${\rm RM}$) towards background sources behind galaxies. We construct models
for the ionized gas and magnetic field patterns of different azimuthal symmetry
(axisymmetric, bisymmetric and quadrisymmetric spiral, and superpositions) plus
a halo magnetic field. $\RM$ fluctuations with a Kolmogorov spectrum due to
turbulent fields and/or fluctuations in ionized gas density are superimposed.
Assuming extrapolated number density counts of polarized sources, we generate a
sample of $\RM$ values within the solid angle of the galaxy. Applying various
templates, we derive the minimum number of background sources and the minimum
quality of the observations. For a large number of sources, reconstruction of
the field structure without precognition becomes possible. Any large-scale
regular component of the magnetic field can be clearly recognized from $\RM$
data with help of the $\chi^2$ criterium. Under favourite conditions, about a
few dozens of polarized sources are sufficient for a reliable result.


title:
Characterization of optimal Transport Plans for the
  Monge-Kantorovich-Problem

abstract:
  We prove that $c$-cyclically monotone transport plans $\pi$ optimize the
Monge-Kantorovich transportation problem under an additional measurability
condition. This measurability condition is always satisfied for finitely
valued, lower semi-continuous cost functions. In particular, this yields a
positive answer to Problem 2.25 in C. Villani's book. We emphasize that we do
not need any regularity conditions as were imposed in the previous literature.


title: Fair Scheduling in OFDMA-based Wireless Systems with QoS Constraints

abstract:
  In this work we consider the problem of downlink resource allocation for
proportional fairness of long term received rates of data users and quality of
service for real time sessions in an OFDMA-based wireless system. The base
station allocates available power and bandwidth to individual users based on
long term average received rates, QoS based rate constraints and channel
conditions. We solve the underlying constrained optimization problem and
propose an algorithm that achieves the optimal allocation. Numerical evaluation
results show that the proposed algorithm provides better QoS to voice and video
sessions while providing more and fair rates to data users in comparison with
existing schemes.


title: Polarization buildup by spin filtering in storage rings

abstract:
  There has been much recent research into polarizing an antiproton beam,
instigated by the recent proposal from the PAX (Polarized Antiproton
eXperiment) project at GSI Darmstadt. It plans to polarize an antiproton beam
by repeated interaction with a polarized internal target in a storage ring. The
method of polarization buildup by spin filtering requires many of the beam
particles to remain within the ring after scattering off the polarized internal
target via electromagnetic and hadronic interactions. Sets of differential
equations which describe the buildup of polarization by spin filtering in many
different scenarios have recently been presented and solved. In this paper we
add to this literature by investigating a scenario where unpolarized particles
are input into the beam at a linearly increasing rate, i.e. the input rate is
ramped up.


title: The Path-Star Transformation and its Effects on Complex Networks

abstract:
  A good deal of the connectivity of complex networks can be characterized in
terms of their constituent paths and hubs. For instance, the Barab\'asi-Albert
model is known to incorporate a significative number of hubs and relatively
short paths. On the other hand, the Watts-Strogatz model is underlain by a long
path and almost complete absence of hubs. The present work investigates how the
topology of complex networks changes when a path is transformed into a star
(or, for long paths, a hub). Such a transformation keeps the number of nodes
and does not increase the number of edges in the network, but has potential for
greatly changing the network topology. Several interesting results are reported
with respect to Erdos-R\'enyi, Barab\'asi-Albert and Watts-Strogats models,
including the unexpected finding that the diameter and average shortest path
length of the former type of networks are little affected by the path-star
transformation. In addition to providing insight about the organization of
complex networks, such transformations are also potentially useful for
improving specific aspects of the network connectivity, e.g. average shortest
path length as required for expedite communication between nodes.


title:
How close are the option pricing formulas of Bachelier and
  Black-Merton-Scholes?

abstract:
  We compare the option pricing formulas of Louis Bachelier and
Black-Merton-Scholes and observe -- theoretically as well as for Bachelier's
original data -- that the prices coincide very well. We illustrate Louis
Bachelier's efforts to obtain applicable formulas for option pricing in
pre-computer time. Furthermore we explain -- by simple methods from chaos
expansion -- why Bachelier's model yields good short-time approximations of
prices and volatilities.


title:
Practical Resource Allocation Algorithms for QoS in OFDMA-based Wireless
  Systems

abstract:
  In this work we propose an efficient resource allocation algorithm for OFDMA
based wireless systems supporting heterogeneous traffic. The proposed algorithm
provides proportionally fairness to data users and short term rate guarantees
to real-time users. Based on the QoS requirements, buffer occupancy and channel
conditions, we propose a scheme for rate requirement determination for delay
constrained sessions. Then we formulate and solve the proportional fair rate
allocation problem subject to those rate requirements and power/bandwidth
constraints. Simulations results show that the proposed algorithm provides
significant improvement with respect to the benchmark algorithm.


title:
Identification of black hole power spectral components across all
  canonical states

abstract:
  From a uniform analysis of a large (8.5 Ms) Rossi X-ray Timing Explorer data
set of Low Mass X-ray Binaries, we present a complete identification of all the
variability components in the power spectra of black holes in their canonical
states. It is based on gradual frequency shifts of the components observed
between states, and uses a previous identification in the black hole low hard
state as a starting point. It is supported by correlations between the
frequencies in agreement with those previously found to hold for black hole and
neutron stars. Similar variability components are observed in neutron stars and
black holes (only the component observed at the highest frequencies is
different) which therefore cannot depend on source-specific characteristics
such as the magnetic field or surface of the neutron star or spin of the black
hole. As the same variability components are also observed across the jet-line
the X-ray variability cannot originate from the outer-jet but is most likely
produced in either the disk or the corona. We use the identification to
directly compare the difference in strength of the black hole and neutron star
variability and find these can be attributed to differences in frequency and
strength of high frequency features, and do not require the absence of any
components. Black holes attain their highest frequencies (in the
hard-intermediate and very-high states) at a level a factor ~6 below the
highest frequencies attained by the corresponding neutron star components,
which can be related to the mass difference between the compact objects in
these systems.


title:
Halo phenomenon in finite many-fermion systems. Atom-positron complexes
  and large-scale study of atomic nuclei

abstract:
  The analysis method proposed in Ref. \cite{rotival07a} is applied to
characterize halo properties in finite many-fermion systems. First, the
versatility of the method is highlighted by applying it to light and
medium-mass nuclei as well as to atom-positron and ion-positronium complexes.
Second, the dependence of nuclear halo properties on the characteristics of the
energy density functional used in self-consistent Hartree-Fock-Bogoliubov
calculations is studied. It is found that (a) the low-density behavior of the
pairing functional and the regularization/renormalization scheme must be chosen
coherently and with care to provide meaningful predictions, (b) the impact of
pairing correlations on halo properties is significant and is the result of two
competing effects, (c) the detailed characteristics of the pairing functional
has however only little importance, (d) halo properties depend significantly on
any ingredient of the energy density functional that influences the location of
single-particle levels; i.e. the effective mass, the tensor terms and the
saturation density of nuclear matter. The latter dependencies give insights to
how experimental data on medium-mass drip-line nuclei can be used in the
distant future to constrain some characteristics of the nuclear energy density
functional. Last but not least, large scale predictions of halos among all
spherical even-even nuclei are performed using specific sets of particle-hole
and particle-particle energy functionals. It is shown that halos in the ground
state of medium-mass nuclei will only be found at the very limit of neutron
stability and for a limited number of elements.


title: DNS of the kappa-mechanism. I. Radial modes in the purely radiative case

abstract:
  Context: Hydrodynamical model of the kappa-mechanism in a purely radiative
case. Aims: First, to determine the physical conditions propitious to
kappa-mechanism in a layer with a configurable conductivity hollow and second,
to perform the (nonlinear) direct numerical simulations (DNS) from the most
favourable setups. Methods: A linear stability analysis applied to radial modes
using a spectral solver and DNS thanks to a high-order finite difference code
are compared. Results: Changing the hollow properties (location and shape) lead
to well-defined instability strips. For a given position in the layer, the
amplitude and width of the hollow appear to be the key parameters to get
unstable modes driven by kappa-mechanism. The DNS achieved from these more
auspicious configurations confirm the growth rates as well as structures of
linearly unstable modes. The nonlinear saturation follows through intricate
couplings between the excited fundamental mode and higher damped overtones.


title: Hecke operators and Hilbert modular forms

abstract:
  Let F be a real quadratic field with ring of integers O and with class number
1. Let Gamma be a congruence subgroup of GL_2 (O). We describe a technique to
compute the action of the Hecke operators on the cohomology H^3 (Gamma; C). For
F real quadratic this cohomology group contains the cuspidal cohomology
corresponding to cuspidal Hilbert modular forms of parallel weight 2. Hence
this technique gives a way to compute the Hecke action on these Hilbert modular
forms.


title:
Gauge invariance and renormalization-group effects in
  transverse-momentum dependent parton distribution functions

abstract:
  A range of issues pertaining to the use of Wilson lines in integrated and
transverse-momentum dependent (TMD) parton distribution functions (PDF) is
discussed. The relation between gauge invariance and the renormalization
properties of the Wilson-line integrals is given particular attention. Using an
anomalous-dimensions based analysis in the light-cone gauge, a generalized
definition of the TMD PDFs is proposed, which employs a cusped Wilson line, and
contains an intrinsic "Coulomb-like" phase.


title:
Geodesic motion in the neighbourhood of submanifolds embedded in warped
  product spaces

abstract:
  We study the classical geodesic motions of nonzero rest mass test particles
and photons in (3+1+n)- dimensional warped product spaces. An important feature
of these spaces is that they allow a natural decoupling between the motions in
the (3+1)-dimensional spacetime and those in the extra n dimensions. Using this
decoupling and employing phase space analysis we investigate the conditions for
confinement of particles and photons to the (3+1)- spacetime submanifold. In
addition to providing information regarding the motion of photons, we also show
that these motions are not constrained by the value of the extrinsic curvature.
We obtain the general conditions for the confinement of geodesics in the case
of pseudo-Riemannian manifolds as well as establishing the conditions for the
stability of such confinement. These results also generalise a recent result of
the authors concerning the embeddings of hypersurfaces with codimension one.


title: The classical pion field in a nucleus

abstract:
  A self-consistent symmetry arises when the nucleon angular momentum j and the
isospin t are coupled to a grand spin G. Closed G shells become sources of a
classical pion field with a hedgehog shape. Although the amplitude of the pion
field, as measured by the chiral angle, is small, it is found to perturb
significantly the energies of the nucleon orbits.


title:
Hydrostatic equilibrium of a porous intracluster medium: implications
  for mass fraction and X-ray luminosity

abstract:
  The presence of dilute hot cavities in the intracluster medium (ICM) at the
cores of clusters of galaxies changes the relation between gas temperature and
its X-ray emission properties. Using the hydrostatic equations of a porous
medium we solve for the ICM density for a given temperature as a function of
the filling factor of dilute bubbles. We find that at a given temperature, the
core X-ray luminosity increases with the filling factor. If the frequency of
AGNs in clusters were higher in the past, then the filling factor could
correspondingly be significant, with implications for the cluster scaling
relations at high redshifts. This is especially important for the core
properties, including the temperature-luminosity ($L_X-T$) relation and
estimates of the core gas mass. The results imply an epoch-dependent
sensitivity of the $L_X-T$ relation in the core to the porosity of the ICM.
Detection of such an effect would give new insights into AGN feedback.


title:
Calculations of the Efficiency of Registration of Thermal Neutrons by
  Complex Converters Constructed on the Basis of Gadolinium Foils

abstract:
  We consider the results of modeling of the efficiency of registration of
thermal neutrons by the converters, which are made from natural gadolinium and
its 157 isotope foils. Efficiency for a case of falling of neutrons under
various angles to a plane of converters is calculated. It is shown, that at
small angles of falling of neutrons to a plane of converters it is possible to
receive the efficiency of registration close to a theoretical limit. Efficiency
of the complex converter made of kapton supporting film with gadolinium
converters layered on both its sides is considered. All calculations are
carried out for four fixed neutron energies, which correspond to the
wavelengths of 1, 1.8, 3 and 4 $\AA$.


title: Erratum: Luminosity function, sizes and FR dichotomy of radio-loud AGN

abstract:
  This erratum corrects a number of formulae containing mistakes in the paper
'Luminosity function, sizes and FR dichotomy of radio-loud AGN', 2007, MNRAS,
v. 381, p.1548. The corrections do not alter any of the conclusions in the
original paper.


title: The complete LQG propagator: II. Asymptotic behavior of the vertex

abstract:
  In a previous article we have show that there are difficulties in obtaining
the correct graviton propagator from the loop-quantum-gravity dynamics defined
by the Barrett-Crane vertex amplitude. Here we show that a vertex amplitude
that depends nontrivially on the intertwiners can yield the correct propagator.
We give an explicit example of asymptotic behavior of a vertex amplitude that
gives the correct full graviton propagator in the large distance limit.


title: A classification of spherical symmetric CR manifolds

abstract:
  In this paper we classify the simply connected, spherical pseudohermitian
manifolds whose Webster metric is CR-symmetric.


title: A Conformal de Rham Complex

abstract:
  We introduce the notion of a conformal de Rham complex of a Riemannian
manifold. This is a graded differential Banach algebra and it is invariant
under quasiconformal maps, in particular the associated cohomology is a new
quasiconformal invariant.


title:
Study of Micro Pixel Photon Counters for a high granularity
  scintillator-based hadron calorimeter

abstract:
  A new Geiger mode avalanche photodiode, the Micro Pixel Photon Counter
(MPPC), was recently released by Hamamatsu. It has a high photo-detection
efficiency in the 420 nm spectral region. This product can represent an elegant
candidate for the design of a high granularity scintillator based hadron
calorimeter for the International Linear Collider. In fact, the direct readout
of the blue scintillation photons with a MPPC is a feasible techological
solution. The readout of a plastic scintillator by a MPPC, both mediated by the
traditional wavelength shifting fiber, and directly coupled, has been
systematically studied.


title:
Review on qudits production and their application to Quantum
  Communication and Studies on Local Realism

abstract:
  The codification in higher dimensional Hilbert Spaces (whose logical basis
states are dubbed qudits in analogy with bidimensional qubits) presents various
advantages both for Quantum Information applications and for studies on
Foundations of Quantum Mechanics.
  Purpose of this review is to introduce qudits, to summarize their application
to Quantum Communication and researches on Local Realism and, finally, to
describe some recent experiment for realizing them.
  A Little more in details: after a short introduction, we will consider the
advantages of testing local realism with qudits, discussing both the 3-4
dimensional case (both for maximally and non-maximally entanglement) and then
the extension to an arbitrary dimension. Afterwards, we will discuss the
theoretical results on using qudits for quantum communication, epitomizing the
outcomes on a larger security in Quantum Key Distribution protocols (again
considering separately qutrits, ququats and generalization to arbitrary
dimension). Finally, we will present the experiments performed up to now for
producing quantum optical qudits and their applications. In particular, we will
mention schemes based on interferometric set-ups, orbital angular momentum
entanglement and biphoton polarization. Finally, we will summarize what
hyperentanglement is and its applications.


title:
Deep Chandra Monitoring Observations of NGC 3379: Catalog of Source
  Properties

abstract:
  We present the properties of the discrete X-ray sources detected in our
monitoring program of the `typical' elliptical galaxy, NGC 3379, observed with
Chandra ACIS-S in five separate pointings, resulting in a co-added exposure of
324-ks. From this deep observation, 132 sources have been detected within the
region overlapped by all observations, 98 of which lie within the D25 ellipse
of the galaxy. These 132 sources range in Lx from 6E35 erg/s (with 3sigma upper
limit <4E36 erg/s) to ~2E39 erg/s, including one source with Lx>1E39 erg/s,
which has been classified as a ULX. From optical data, 10 X-ray sources have
been determined to be coincident with a globular cluster, these sources tend to
have high X-ray luminosity, with three of these sources exhibiting Lx> 1E38
erg/s. From X-ray source photometry, it has been determined that the majority
of the 132 sources that have well constrained colors, have values that are
consistent with typical LMXB spectra. Additionally to this, a sub-population of
10 sources has been found to exhibit very hard spectra and it is expected that
most of these sources are absorbed background AGN. There are 64 sources in this
population that exhibit long-term variability, indicating that they are
accreting compact objects. Five of these sources have been identified as
transient candidates, with a further 3 possible transients. Spectral variations
have also been identified in the majority of the source population, where a
diverse range of variability has been identified, indicating that there are
many different source classes located within this galaxy.


title:
Conception individuelle et collective. Approche de l'ergonomie cognitive
  [Individual and Collective Design. The Cognitive-Ergonomics Approach]

abstract:
  This text presents the cognitive-ergonomics approach to design, in both its
individual and collective form. It focuses on collective design with respect to
individual design. The theoretical framework adopted is that of information
processing, specified for design problems. The cognitive characteristics of
design problems are presented: the effects of their ill-defined character and
of the different types of representation implemented in solving these problems,
amongst others the more or less "satisficing" character of the different
possible solutions. The text first describes the cognitive activities
implemented in both individual and collective design: different types of
control activities and of the executive activities of solution development and
evaluation. Specific collective-design characteristics are then presented:
co-design and distributed-design activities, temporo-operative and cognitive
synchronisation, and different types of argumentation, of co-designers'
intervention modes in the design process, of solution-proposals evaluation. The
paper concludes by a confrontation between the two types of design, individual
and collective.


title: Convergence of Singular integrals with general measures

abstract:
  We show that L^2-bounded singular integral in metric spaces with respect to
general measures and kernels converge weakly. This implies a kind of average
convergence almost everywhere. For measures with zero density we prove the
almost everywhere existence of principal values.


title:
Microscopic Derivation of Collective Hamiltonian by Means of the
  Adiabatic Self-Consistent Collective Coordinate Method

abstract:
  Microscopic dynamics of the oblate-prolate shape coexistence/mixing phenomena
in 68Se and 72Kr are studied by means of the adiabatic self-consistent
collective coordinate (ASCC) method in conjunction with the
pairing-plus-quadrupole (P+Q) Hamiltonian including the quadrupole pairing
interaction. Quantum collective Hamiltonian is constructed, and excitation
spectra, spectroscopic quadrupole moments and quadrupole transition properties
are evaluated. The effect of the time-odd pair field on the collective mass
(inertia function) of the large-amplitude vibration and the rotational moments
of inertia about three principal axes is evaluated. Basic properties of the
shape coexistence/mixing are well reproduced. The calculation indicates that
the oblate-prolate shape mixing decreases as the angular momentum increases.


title: The Behavior of Electronic Interferometers in the Non-Linear Regime

abstract:
  We investigate theoretically the behavior of the current oscillations in an
electronic Mach-Zehnder interferometer (MZI) as a function of its source bias.
Recently, The MZI interference visibility showed an unexplained lobe pattern
behavior with a peculiar phase rigidity. Moreover, the effect did not depend on
the MZI paths difference. We argue that these effects may be a new many-body
manifestation of particle-wave duality of quantum mechanics. When biasing the
interferometer sources beyond the linear response regime, quantum shot-noise (a
particle phenomena) must affect the interference pattern of the electrons that
creates it, as a result from a simple invariance argument. An approximate
solution of the interacting Hamiltonian indeed shows that the interference
visibility has a lobe pattern with applied bias with a period proportional to
the average path length and independent of the paths difference, together with
a phase rigidity.


title:
Spin Susceptibility of Interacting Two-dimensional Electrons with
  Anisotropic Effective Mass

abstract:
  We report measurements of the spin susceptibility in dilute (rs up to 10)
AlAs two-dimensional (2D) electrons occupying a single conduction-band valley
with an anisotropic in-plane Fermi contour, characterized by longitudinal and
transverse effective masses, ml and mt. As the density is decreased, the spin
susceptibility is significantly enhanced over its band value, reflecting the
role of interaction. Yet the enhancement is suppressed compared to the results
of quantum Monte Carlo based calculations that take the finite thickness of the
electron layer into account but assume an isotropic effective mass equal to
sqrt(ml.mt). Proper treatment of an interacting 2D system with an anisotropic
effective mass therefore remains a theoretical challenge.


title:
On the performance of Golden space-time trellis coded modulation over
  MIMO block fading channels

abstract:
  The Golden space-time trellis coded modulation (GST-TCM) scheme was proposed
in \cite{Hong06} for a high rate $2\times 2$ multiple-input multiple-output
(MIMO) system over slow fading channels. In this letter, we present the
performance analysis of GST-TCM over block fading channels, where the channel
matrix is constant over a fraction of the codeword length and varies from one
fraction to another, independently. In practice, it is not useful to design
such codes for specific block fading channel parameters and a robust solution
is preferable. We then show both analytically and by simulation that the
GST-TCM designed for slow fading channels are indeed robust to all block fading
channel conditions.


title:
Simple model for transport phenomena : Microscopic construction of
  Maxwell Demon like engine

abstract:
  We present a microscopic Hamiltonian framework to develop Maxwell demon like
engine. Our model consists of a equilibrium thermal bath and a non-equilibrium
bath; latter generated by driving with an external stationary, Gaussian noise.
The engine we develop, can be considered as a device to extract work by
modifying internal fluctuations. Our theoretical analysis focusses on finding
the essential ingredients necessary for generating fluctuation induced
transport under non-equilibrium condition. An important outcome of our model is
that the net motion occurs when the non-linear bath is modulated by the
external noise, creating the non-zero effective temperature even when the
temperature of both the baths are same.


title: A further look at particle annihilation in dark matter caustics

abstract:
  Dark matter caustics are small scale, high density structures believed to
exist in galaxies like ours. If the dark matter consists of Weakly Interacting
Massive Particles, these caustics may be detected by means of the gamma rays
produced by dark matter particle annihilation. We discuss particle annihilation
in outer and inner caustics and provide sky maps of the expected gamma ray
distribution.


title: Gauge/Gravity Theory with Running Dilaton and Running Axion

abstract:
  We present a new gauge/gravity duality construction of the Klebanov-Strassler
throat which takes corrections to the anomalous mass dimension proposed in [1]
into account on the gauge theory side and both the dilaton and the axion run on
the gravity side. The corresponding supergravity solutions are found using
equations for type IIB flows with N=1 supersymmetry obtained in [2]. We find
that magnetic couplings of the axion to D7-branes filling 4-d spacetime and
wrapping 4-cycles at locations of duality transitions and invisible Dirac
8-branes whose worldvolume emanates from the worldvolume of the D7-branes are
the sources for the runnings of the dilaton and the axion. Our construction
provides the first explicit example of a gauge/gravity duality mapping with a
running dilaton or a running axion which is an important component towards
finding gravity duals to gauge theories with physically more interesting
renormalization group flows such as pure confining gauge theories in four
dimensions. The D7-branes also serve as gravitational source for Seiberg
duality transitions. The supergravity background has distinct features which
could be useful for constructing cosmological models and studying possibilities
for probing stringy signatures from the early universe.


title: On marginally outer trapped surfaces in stationary and static spacetimes

abstract:
  In this paper we prove that for any spacelike hypersurface containing an
untrapped barrier in a stationary spacetime satisfying the null energy
condition, any marginally outer trapped surface cannot lie in the exterior
region where the stationary Killing vector is timelike. In the static case we
prove that any marginally outer trapped surface cannot penetrate into the
exterior region where the static Killing vector is timelike. In fact, we prove
these result at an initial data level, without even assuming existence of a
spacetime. The proof relies on a powerful theorem by Andersson and Metzger on
existence of an outermost marginally outer trapped surface.


title:
An Alternative View of the Universe Structure (on the invalidity of the
  four dimensional space-time concept)

abstract:
  The model of the Universe in this paper uses equations of the unperturbed
Keplerian motion. They have been updated, complementied and generalized when
the solution of these equations is the characteristic function of a random
value from the theory of probabilities. Argument of the differential equation
in this case is any more time, an interval of time between sections of a random
stationary prosess. In this paper this time interval is referred to as flexible
(elastic) time due to its many non-trivial properties. It is proved flexible
time does not depend on the space which makes invalid the four dimensional
space-time concept. The Universe becomes stationary and Eucledian. It is
proved: 1. the advavce of Mercury's perihelion versus the predictions in
accordance with the universal gravity law results inequality of the
coefficients in the correlation equations of Keplerian moution along axes x, y
and z; 2. the velocity of propagation of harmonic oscillation in the Uneverse
is not constant; 3. long-range interaction, i.e. instantaneous communication
between any two points of space in tne Universe is possible; 4. the Universe is
a closed-loop informatiom-energy system which revives the nature and acts as a
barrier to the second law of thermodynamics where stars are treated as machines
which accumulate energy by moving. Physics in the Universe is conceptually
different from that of the Earth and, respectively, needs methods of
investigation different from the ones which are used today. Numerous
astronomical supervision and the researches lead by known astrophysicist
N.A.Kozyrev personally or under his management confirm adequacy of the model in
the present paper.


title: Spin Frustration and Magnetic Exchange in Cobalt Aluminum Oxide Spinels

abstract:
  We report on x-ray diffraction, magnetic susceptibility, electron- spin
resonance and heat- capacity studies of Co[Al_1-xCo_x]_2O_4 for Co
concentrations 0<x<1. In this spinel system only the A-site Co^2+ cation is
magnetic, while the non-magnetic B-site Al^3+ is substituted by the low-spin
non-magnetic Co^3+, and it is possible to investigate the complete phase
diagram from Co^2+Al^3+_2O_4 to Co^2+Co^3+_2O_4. All samples reveal large
negative Curie-Weiss temperatures Theta_CW of the order of -110 K independent
of concentration, which is attributed to a high multiplicity of the
superexchange interactions between the A-site Co^2+ cations. A pure
antiferromagnetic state is found for x = 1.0 and 0.9 with Neel temperatures T_N
= 29.5 K and 21.2 K, respectively, as evidenced by lambda-like anomalies in the
specific heat. Compositions with 0.3<x<0.75 show smeared out strongly reduced
magnetic ordering temperatures. At low temperatures, a T^2.5 dependence of the
specific heat is indicative of a spin-liquid state. For x < 0.2 a T^2
dependence of the specific heat and a spin-glass like behavior of the
susceptibility below T_f = 4.7 K are observed. The high value of the
frustration parameter f = |Theta_CW|/T_f > 10 indicates the presence of strong
spin frustration at least for x < 0.6. The frustration mechanism is attributed
to competing nearest neighbor and next-nearest neighbor superexchange
interactions between the A-site Co^2+ ions.


title: Local probabilities for random walks conditioned to stay positive

abstract:
  Let S_0=0,{S_n, n>0} be a random walk generated by a sequence of i.i.d.
random variables X_1,X_2,... and let \tau^{-} be the first descending ladder
epoch. Assuming that the distribution of X_1 belongs to the domain of
attraction of an \alpha-stable law we study the asymptotic behavior of the
local probabilities P(\tau ^{-}=n) and the conditional local probabilities
P(S_n\in [x,x+y)|\tau^{-}>n) for fixed y and x=x(n)\in (0,\infty).


title: Substrate limited electron dynamics in graphene

abstract:
  We study the effects of polarizable substrates such as SiO2 and SiC on the
carrier dynamics in graphene. We find that the quasiparticle spectrum acquires
a finite broadening due to the long-range interaction with the polar modes at
the interface between graphene and the substrate. This mechanism results in a
density dependent electrical resistivity, that exhibits a sharp increase around
room temperature, where it can become the dominant limiting factor of electron
transport. The effects are weaker in doped bilayer graphene, due to the more
conventional parabolic band dispersion.


title:
Probabilistic approach to a proliferation and migration dichotomy in the
  tumor cell invasion

abstract:
  The proliferation and migration dichotomy of the tumor cell invasion is
examined within a two-component continuous time random walk (CTRW) model. The
balance equations for the cancer cells of two phenotypes with random switching
between cell proliferation and migration are derived. The transport of tumor
cells is formulated in terms of the CTRW with an arbitrary waiting time
distribution law, while proliferation is modelled by a logistic growth. The
overall rate of tumor cell invasion for normal diffusion and subdiffusion is
determined.


title:
X-rays from young stars - a summary of highlights from the XMM-Newton
  Extended Survey of the Taurus Molecular Cloud (XEST)

abstract:
  The XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST) is a
survey of the nearest large star-forming region, the Taurus Molecular Cloud
(TMC), making use of all instruments on board the XMM-Newton X-ray observatory.
The survey, presently still growing, has provided unprecedented spectroscopic
results from nearly every observed T Tauri star, and from ~50% of the studied
brown dwarfs and protostars. The survey includes the first coherent statistical
sample of high-resolution spectra of T Tauri stars, and is accompanied by an
U-band/ultraviolet imaging photometric survey of the TMC. XEST led to the
discovery of new, systematic X-ray features not possible before with smaller
samples, in particular the X-ray soft excess in classical T Tauri stars and the
Two-Absorber X-ray (TAX) spectra of jet-driving T Tauri stars. This paper
summarizes highlights from XEST and reviews the key role of this large project.


title: Exponential sums and rank of persymmetric matrices over F_2

abstract:
  Over the finite field with two elements, we present a method for obtaining
explicit expressions for the number of rank i matrices of the form A above B,
where A is persymmetric (A matrix [a(i,j)] is persymmetric if a(i,j) = a(r,s)
for i+j = r+s).


title: A remark on singularities of primitive cohomology classes

abstract:
  Green and Griffiths have introduced several notions of singularities
associated with normal functions, especially in connection with middle
dimensional primitive Hodge classes. In this note, by using the more elementary
aspects of the Decomposition Theorem, we define global and local singularities
associated with primitive middle dimensional cohomology classes and by using
the Relative Hard Lefschetz Theorem, we show that these singularities detect
the global and local triviality of the primitive class. In a final section, we
write-up a classical inductive argument relating the Hodge conjecture to the
local non-vanishing of primitive classes.


title:
E(5) and X(5) shape phase transitions within a Skyrme Hartree-Fock + BCS
  approach

abstract:
  Self-consistent Skyrme Hartree-Fock plus BCS calculations are performed to
generate potential energy curves (PEC) in various chains of Pd, Xe, Ba, Nd, Sm,
Gd, and Dy isotopes. The evolution of shapes with the number of nucleons is
studied in a search for signatures of E(5) and X(5) critical point symmetries.
It is shown that the energy barriers in the PECs are determined to a large
extent by the treatment of the pairing correlations.


title:
Evidence for a non-universal stellar initial mass function from the
  integrated properties of SDSS galaxies

abstract:
  This paper revisits the classical Kennicutt method for inferring the stellar
initial mass function (IMF) from the integrated light properties of galaxies.
The large size, uniform high quality data set from the Sloan Digital Sky Survey
DR4 is combined with more in depth modeling and quantitative statistical
analysis to search for systematic IMF variations as a function of galaxy
luminosity. Galaxy H alpha equivalent widths are compared to a broadband color
index to constrain the IMF. This parameter space is useful for breaking
degeneracies which are traditionally problematic. Age and dust corrections are
largely orthogonal to IMF variations. In addition the effects of metallicity
and smooth star formation history e-folding times are small compared to IMF
variations. We find that for the sample as a whole the best fitting IMF slope
above 0.5 M_sun is Gamma = 1.4535 with a negligible random error of +/- 0.0004
and a systematic error of +/- 0.1. Galaxies brighter than around M_r,0.1 = -20
(including galaxies like the Milky Way which has M_r,0.1 ~ -21) are well fit by
a universal Gamma ~ 1.4 IMF, similar to Salpeter, and smooth, exponential star
formation histories (SFH). Fainter galaxies prefer steeper IMFs and the quality
of the fits reveal that for these galaxies a universal IMF with smooth SFHs is
actually a poor assumption. Several sources of sample bias are ruled out as the
cause of these luminosity dependent IMF variations. Analysis of bursting SFH
models shows that an implausible coordination of burst times is required to fit
a universal IMF to the M_r,0.1 = -17 galaxies. This leads to the conclusions
that the IMF in low luminosity galaxies has fewer massive stars, either by
steeper slope or lower upper mass cutoff, and is not universal.


title: Impurity-induced step interactions: a kinetic Monte-Carlo study

abstract:
  A one-dimensional continuum description of growth on vicinal surfaces in the
presence of immobile impurities predicts that the impurities can induce step
bunching when they suppress the diffusion of adatoms on the surface. In the
present communication we verify this prediction by kinetic Monte-Carlo
simulations of a two-dimensional solid-on-solid model. We identify the
conditions where quasi one-dimensional step flow is stable against island
formation or step meandering, and analyse in detail the statistics of the
impurity concentration profile. The sign and strength of the impurity-induced
step interactions is determined by monitoring the motion of pairs of steps.
Assemblies containing up to 20 steps turn out to be unstable towards the
emission of single steps. This behavior is traced back to the small value of
the effective, impurity-induced attachment asymmetry for adatoms. An analytic
estimate for the critical number of steps needed to stabilize a bunch is
derived and confirmed by simulations of a one-dimensional model.


title: Top quark rare decays in a two Higgs doublet model for the top

abstract:
  The two Higgs doublet model for the top (T2HDM) is a 2HDM in which the top
quark receives a special status, which endows it with a naturally large mass,
and also gives rise to unique FC charged and neutral scalar interactions. We
calculate the BR of the t->ch and h->tc rare decays in the T2HDM, at 1-loop and
tree level. We find that the FC scalar interactions play a significant role in
these decays. We find that the BR of these decays at 1-loop level in the T2HDM
can be significantly enhanced over the 2HDM-I,II, reaching up to ~10^-4, and
that the BR(t->ch) in the T2HDM can be detected at the LHC.


title:
Detector of alpha particles and x-rays operating in ambient air in pulse
  counting mode or/and with gas amplification

abstract:
  Ionization chambers working in ambient air in current detection mode are
widely used in several applications such as smoke detection, dosimetry,
therapeutic beam monitoring and cetera. The aim of this work was to investigate
if gaseous detectors can operate in ambient air in pulse counting mode as well
as with gas amplification. . To investigate the feasibility of this method two
types of open- end gaseous detectors were build and successfully tested. The
first one was a single wire or multiwire cylindrical geometry detector
operating in pulse mode at a gas gain of 1. The second type alpha detector was
an innovative GEM-like detector with resistive electrodes operating in air in
avalanche mode at high gas gains (up to 10E4). A detailed comparison between
these two detectors is given as well as comparison with the commercially
available alpha detectors. The main advantages of gaseous detectors operating
in air in a pulse detection mode are their simplicity, low cost and high
sensitivity. One of the possible applications of these new detectors is alpha
particle background monitors which, due to their low cost can find wide
application not only in houses, but in public areas: airports, railway station
and so on.


title:
Fractional martingales and characterization of the fractional Brownian
  motion

abstract:
  In this paper we introduce the notion of fractional martingale as the
fractional derivative of order $\alpha$ of a continuous local martingale, where
$\alpha\in(-{1/2},{1/2})$, and we show that it has a nonzero finite variation
of order $\frac{2}{1+2\alpha}$, under some integrability assumptions on the
quadratic variation of the local martingale. As an application we establish an
extension of L\'evy's characterization theorem for the fractional Brownian
motion.


title:
Monitoring atom-atom entanglement and decoherence in a solvable
  tripartite open system in cavity QED

abstract:
  We present a fully analytical solution of the dynamics of two strongly-driven
atoms resonantly coupled to a dissipative cavity field mode. We show that an
initial atom-atom entanglement cannot be increased. In fact, the atomic Hilbert
space divides into two subspaces, one of which is decoherence free so that the
initial atomic entanglement remains available for applications, even in
presence of a low enough atomic decay rate. In the other subspace a measure of
entanglement, decoherence, and also purity, are described by a similar
functional behavior that can be monitored by joint atomic measurements.
Furthermore, we show the possible generation of Schr\"odinger-cat-like states
for the whole system in the transient regime, as well as of entanglement for
the cavity field and the atom-atom subsystems conditioned by measurements on
the complementary subsystem.


title:
On the effects of geographical constraints on task execution in complex
  networks

abstract:
  In the present work we investigate the effects of spatial constraints on the
efficiency of task execution in systems underlain by geographical complex
networks where the probability of connection decreases with the distance
between the nodes. The investigation considers several configurations of the
parameters defining the network connectivity, and the Barabasi-Albert network
model is also considered for comparisons. The results show that the effect of
connectivity is significant only for shorter tasks, that the locality of
connections implied by the spatial constraints reduces efficency, and that the
addition of edges can improve the efficiency of the execution, although with
increasing locality of the connections the improvement is small.


title:
Instanton Induced Open String Superpotentials and Branes at
  Singularities

abstract:
  We study different aspects of the non-perturbative superpotentials induced by
Euclidean E3-branes on systems of D3/D7-branes located at Abelian orbifold
singularities. We discuss in detail how the induced couplings are consistent
with the U(1) symmetries carried by the D3/D7-branes. We construct different
compact and non-compact examples, and show phenomenologically relevant
couplings like $\mu$-terms or certain Yukawa couplings generated by these E3
instantons. Some other novel effects are described. We show an example where
E3-instantons combine with standard gauge instantons to yield new
multi-instanton effects contributing to superpotential, along the lines of
ref.\cite{geu}. In the case of non-SUSY $Z_N$ tachyon-free singularities it is
shown how E3-instantons give rise to non perturbative scalar couplings
including exponentially suppressed scalar bilinears.


title: Sharp Superconductor-Insulator Transition in Short Wires

abstract:
  Recent experiments on short MoGe nanowires show a sharp
superconductor-insulator transition tuned by the normal state resistance of the
wire, with a critical resistance of $R_c\approx R_Q= h/(4e^2)$. These results
are at odds with a broad range of theoretical work on Josephson-like systems
that predicts a smooth transition, tuned by the value of the resistance that
shunts the junction. We develop a self-consistent renormalization group
treatment of interacting phase-slips and their dual counterparts, correlated
cooper pair tunneling, beyond the dilute approximation. This analysis leads to
a very sharp transition with a critical resistance of $R_Q$. The addition of
the quasi-particles' resistance at finite temperature leads to a quantitative
agreement with the experimental results. This self-consistent renormalization
group method should also be applicable to other physical systems that can be
mapped onto similar sine-Gordon models, in the previously inaccessible
intermediate-coupling regime.


title:
Simulating Van der Waals-interactions in water/hydrocarbon-based complex
  fluids

abstract:
  In systems composed of water and hydrocarbons Van der Waals-interactions are
dominated by the non-retarded, classical (Keesom) part of the
Lifshitz-interaction; the interaction is screened by salt and extends over
mesoscopic distances of the order of the size of the (micellar) constituents of
complex fluids. We show that these interactions are included intrinsically in a
recently introduced local Monte Carlo algorithm for simulating electrostatic
interactions between charges in the presence of non-homogeneous dielectric
media.


title: A study of Galois objects for algebraic quantum groups

abstract:
  We supplement the study of Galois theory for algebraic quantum groups started
in the paper 'Galois Theory for Multiplier Hopf Algebras with Integrals' by A.
Van Daele and Y.H. Zhang. We examine the structure of the Galois objects:
algebras equipped with a Galois coaction such that only the scalars are
coinvariants. We show how their structure is as rich as the one of the quantum
groups themselves: there are two distinguished weak K.M.S. functionals, related
by a modular element, and there is an analogue of the antipode squared. We also
show how to reflect the quantum group across the Galois object to obtain a
(possibly) new algebraic quantum group. We end by considering an example.


title:
Clumpy photon-dominated regions in Carina. I. [CI] and mid-J CO lines in
  two 4'x4' fields

abstract:
  The Carina region is an excellent astrophysical laboratory for studying the
feedback mechanisms of newly born, very massive stars within their natal giant
molecular clouds (GMCs) at only 2.35 kpc distance. We use a clumpy PDR model to
analyse the observed intensities of atomic carbon and CO and to derive the
excitation conditions of the gas. The NANTEN2-4m submillimeter telescope was
used to map the [CI] 3P1-3P0, 3P2-3P1 and CO 4-3, 7-6 lines in two 4'x4'
regions of Carina where molecular material interfaces with radiation from the
massive star clusters. One region is the northern molecular cloud near the
compact OB cluster Tr14, and the second region is in the molecular cloud south
of etaCar and Tr16. These data were combined with 13CO SEST spectra, HIRES/IRAS
60um and 100um maps of the FIR continuum, and maps of 8um IRAC/Spitzer and MSX
emission. We used the HIRES far-infrared dust data to create a map of the FUV
field heating the gas. The northern region shows an FUV field of a few 1000 in
Draine units while the field of the southern region is about a factor 10
weaker. We constructed models consisting of an ensemble of small spherically
symmetric PDR clumps within the 38" beam (0.43pc), which follow canonical
power-law mass and mass-size distributions. We find that an average local clump
density of 2x10**5 cm-3 is needed to reproduce the observed line emission at
two selected interface positions. Stationary, clumpy PDR models reproduce the
observed cooling lines of atomic carbon and CO at two positions in the Carina
Nebula.


title:
Solving non-linear equations of longitudinal and transverse electron
  waves in collisionless Maxwellian plasma

abstract:
  We have considered an expansion of solutions of the non-linear equations for
both longitudinal and transverse waves in collisionless Maxwellian plasma in
series of non-damping overtones of the field E(x,t) and electron velocity
distribution function f=f(0) +f(1) where f(0) is background Maxwellian electron
distribution function and f(1) is perturbation. The electrical field and
perturbation f(1) are presented as a series of non-damping harmonics with
increasing frequencies of the order n and the same propagation speed. It is
shown presence of recurrent relations for arising overtones. Convergence of the
series is provided by a power law parameter series convergence. There are
proposed also successive procedures of cutting off the distribution function
f(1) to the condition of positivity f near the singularity points where kinetic
equation becomes inapplicable. In this case, at poles absence the solution
reduces to non-damping Vlasov waves (oscillations). In the case of transverse
waves, dispersion equation has two roots, corresponding to the branches of fast
electromagnetic and slow electron waves. There is noted a possibility of
experimental testing appearing exotic results with detecting frequencies and
amplitudes of n-order overtones.


title: Selective screenability in topological groups

abstract:
  We examine the selective screenability property in topological groups. In the
metrizable case we also give characterizations in terms of the Haver property
and finitary Haver property respectively relative to left-invariant metrics. We
prove theorems stating conditions under which the properties are preserved by
products. Among metrizable groups we characterize the ones of countable
covering dimension by a natural game.


title:
Super-horizon fluctuations and acoustic oscillations in relativistic
  heavy-ion collisions

abstract:
  We focus on the initial state spatial anisotropies, originating at the
thermalization stage, for central collisions in relativistic heavy-ion
collisions. We propose that a plot of the root mean square values of the flow
coefficients $\sqrt{\bar {v_n^2}} \equiv v_n^{rms}$, calculated in a lab fixed
coordinate system, for a large range of $n$, from 1 to about 30, can give
non-trivial information about the initial stages of the system and its
evolution. We also argue that for all wavelengths $\lambda$ of the anisotropy
(at the surface of the plasma region) much larger than the acoustic horizon
size $H_s^{fr}$ at the freezeout stage, the resulting values of $v_n^{rms}$
should be suppressed by a factor of order $2H_s^{fr}/\lambda$. With initial
flow being zero, we discuss the possibility that the resulting flow could show
imprints of coherent oscillations in the plot of $v_n^{rms}$ for sub-horizon
modes. For gold-gold collision at 200 GeV, these features are expected to occur
for n $\ge$ 5, with $n < 4$ modes showing supression. This has strong
similarities with the physics of the anisotropies of the cosmic microwave
background radiation (CMBR) resulting from inflationary density fluctuations in
the universe. It seems possible that the statistical fluctuations due to finite
multiplicity may not be able to mask such features in the flow data, or, at
least a non-trivial overall shape of the plot of $v_n^{rms}$ may be inferred.
In that case, the successes of analysis of CMBR anisotropy power spectrum to
get cosmological parameters can be applied for relativistic heavy-ion
collisions to learn about various relevant parameters at the early stages of
the evolving system.


title:
Renormalization group study of transport through a superconducting
  junction of multiple one-dimensional quantum wires

abstract:
  We investigate transport properties of a superconducting junction of many ($N
\ge 2$) one-dimensional quantum wires. We include the effectofelectron-electron
interaction within the one-dimensional quantum wire using a weak interaction
renormalization group procedure. Due to the proximity effect, transport across
the junction occurs via direct tunneling as well as via the crossed Andreev
channel. We find that the fixed point structure of this system is far more rich
than the fixed point structure of a normal metal$-$superconductor junction ($N
= 1$), where we only have two fixed points - the fully insulating fixed point
or the Andreev fixed point. Even a two wire (N=2)system with a superconducting
junction i.e. a normalmetal$-$superconductor$-$normal metal structure, has
non-trivialfixed points with intermediate transmissions and reflections. We
also include electron-electron interaction induced back-scattering in the
quantum wires in our study and hence obtain non-Luttinger liquid behaviour. It
is interesting to note that {\textsl{(a)}} effects due to inclusion of
electron-electron interaction induced back-scattering in the wire, and
{\textsl{(b)}} competition between the charge transport via the electron and
hole channels across the junction, give rise to a non-monotonic behavior of
conductance as a functionof temperature. We also find that transport across the
junction depends on two independent interaction parameters. The first one is
due to the usual correlations coming from Friedel oscillations for spin-full
electrons giving rise to the well-known interaction parameter (${{\alpha =
(g_2-2g_1)/2 \pi \hbar v_F}}$). The second one arises due to the scattering
induced by the proximity of the superconductor and is given by(${{\alpha^\prime
= (g_2 + g_1)/2 \pi \hbar v_F}}$).


title: Phase diagram of the dissipative quantum particle in a box

abstract:
  We analyze the phase diagram of a quantum particle confined to a finite
chain, subject to a dissipative environment described by an Ohmic spectral
function. Analytical and numerical techniques are employed to explore both the
perturbative and non-perturbative regime of the model. For small dissipation
the coupling to the environment leads to a narrowing of the density
distribution, and to a displacement towards the center of the array of
accessible sites. For large values of the dissipation, we find a phase
transition to a doubly degenerate phase which reflects the formation of an
inhomogeneous effective potential within the array.


title: Tracing intermediate-mass black holes in the Galactic Centre

abstract:
  We have developed a new method for post-Newtonian, high-precision integration
of stellar systems containing a super-massive black hole (SMBH), splitting the
forces on a particle between a dominant central force and perturbations. We
used this method to perform fully collisional N-body simulations of
inspiralling intermediate-mass black holes (IMBHs) in the centre of the Milky
Way. We considered stellar cusps of different power-law indices and analysed
the effects of IMBHs of different masses, all starting from circular orbits at
an initial distance of 0.1 pc.
  Our simulations show how IMBHs deplete the central cusp of stars, leaving
behind a flatter cusp with slope consistent with what has recently been
observed. If an additional IMBH spirals into such a flat cusp, it can take 50
Myr or longer to merge with the central SMBH, thus allowing for direct
observation in the near future. The final merger of the two black holes
involves gravitational wave radiation which may be observable with planned
gravitational wave detectors.
  Furthermore, our simulations reveal detailed properties of the hypervelocity
stars (HVSs) created, and how generations of HVSs can be used to trace IMBHs in
the Galactic Centre. We find that significant rotation of HVSs (which would be
evidence for an IMBH) can only be expected among very fast stars (v > 1000
km/s). Also, the probability of creating a hypervelocity binary star is found
to be very small.


title: The Fermat cubic and special Hurwitz loci in M_g

abstract:
  We compute the class of the locus in M_g of curves having a pencil with two
unspecified triple ramification points. This is the first example of a
geometric divisor on M_g which is not the pull-back of a divisor on the moduli
space of pseudo-stable curves. This space, in which elliptic tails are replaced
by cusps, appears as a result of the first divisorial contraction in the
minimal model program for M_g. In particular, we show that our divisor picks-up
the locus of Fermat cubic tails when restricted to the boundary divisor of
elliptic tails. We also give various enumerative applications concerning
coverings of the generic curve having special ramification behaviour.


title: Heavy Quarkonium Physics-Theoretical Status

abstract:
  We briefly review the theoretical status and the open theoretical challenges
in the physics of heavy quarkonium.


title: Vibrational excitations in systems with correlated disorder

abstract:
  We investigate a $d$-dimensional model ($d$ = 2,3) for sound waves in a
disordered environment, in which the local fluctuations of the elastic modulus
are spatially correlated with a certain correlation length. The model is solved
analytically by means of a field-theoretical effective-medium theory
(self-consistent Born approximation) and numerically on a square lattice. As in
the uncorrelated case the theory predicts an enhancement of the density of
states over Debye's $\omega^{d-1}$ law (``boson peak'') as a result of
disorder. This anomay becomes reinforced for increasing correlation length
$\xi$. The theory predicts that $\xi$ times the width of the Brillouin line
should be a universal function of $\xi$ times the wavenumber. Such a scaling is
found in the 2d simulation data, so that they can be represented in a universal
plot. In the low-wavenumber regime, where the lattice structure is irrelevant
there is excellent agreement between the simulation at small disorder. At
larger disorder the continuum theory deviates from the lattice simulation data.
It is argued that this is due to an instability of the model with stronger
disorder.


title:
Homotopical equivalence of combinatorial and categorical semantics of
  process algebra

abstract:
  It is possible to translate a modified version of K. Worytkiewicz's
combinatorial semantics of CCS (Milner's Calculus of Communicating Systems) in
terms of labelled precubical sets into a categorical semantics of CCS in terms
of labelled flows using a geometric realization functor. It turns out that a
satisfactory semantics in terms of flows requires to work directly in their
homotopy category since such a semantics requires non-canonical choices for
constructing cofibrant replacements, homotopy limits and homotopy colimits. No
geometric information is lost since two precubical sets are isomorphic if and
only if the associated flows are weakly equivalent. The interest of the
categorical semantics is that combinatorics totally disappears. Last but not
least, a part of the categorical semantics of CCS goes down to a pure
homotopical semantics of CCS using A. Heller's privileged weak limits and
colimits. These results can be easily adapted to any other process algebra for
any synchronization algebra.


title:
Ferroelectrically induced weak-ferromagnetism in a single-phase
  multiferroic by design

abstract:
  We present a strategy to design structures for which a polar lattice
distortion induces weak ferromagnetism. We identify a large class of
multiferroic oxides as potential realizations and use density-functional theory
to screen several promising candidates. By elucidating the interplay between
the polarization and the Dzyaloshinskii-Moriya vector, we show how the
direction of the magnetization can be switched between 180$^{\circ}$ symmetry
equivalent states with an applied electric field.


title:
Pupil stabilization for SPHERE's extreme AO and high performance
  coronagraph system

abstract:
  We propose a new concept of pupil motion sensor for astronomical adaptive
optics systems and present experimental results obtained during the first
laboratory validation of this concept. Pupil motion is an important issue in
the case of extreme adaptive optics, high contrast systems, such as the
proposed Planet Finder instruments for the ESO and Gemini 8-meter telescopes.
Such high contrast imaging instruments will definitively require pupil
stabilization to minimize the effect of quasi-static aberrations. The concept
for pupil stabilization we propose uses the flux information from the AO system
wave-front sensor to drive in closed loop a pupil tip-tilt mirror located in a
focal plane. A laboratory experiment validates this concept and demonstrates
its interest for high contrast imaging instrument.


title:
Cellular structures, quasisymmetric mappings, and spaces of homogeneous
  type

abstract: A class of Cantor-type spaces and related geometric structures are discussed.


title:
Recursive state estimation for noncausal discrete-time descriptor
  systems under uncertainties

abstract:
  This paper describes a method for the online state estimation of systems
described by a general class of linear noncausal time-varying difference
descriptor equations subject to uncertainties. The method is based on the
notions of a linear minimax estimation and an index of causality introduced
here for singular difference equations. The online minimax estimator is derived
by the application of the dynamical programming and Moore's pseudoinverse
theory to the minimax estimation problem. It coincides with Kalman's filter for
regular systems. A numerical example of the state estimation for 2D noncasual
descriptor system is presented.
  Keywords: Kalman filtering, online state observer, guaranteed estimation,
descriptor systems, singular systems, DAEs.


title: 4He adsorbed inside (10,10) single walled carbon nanotubes

abstract:
  Diffusion Monte Carlo calculations on the adsorption of $^4$He in open-ended
single walled (10,10) nanotubes are presented. We have found a first order
phase transition separating a low density liquid phase in which all $^4$He
atoms are adsorbed close to the tube wall and a high density arrangement
characterized by two helium concentric layers. The energy correction due to the
presence of neighboring tubes in a bundle has also been calculated, finding it
negligible in the density range considered.


title:
Parabolic Iterated Function Systems with Applications to the Backward
  Continued Fractions

abstract:
  To the Renyi or backward continued fraction transformation we associate a
parabolic iterated function system whose limit set has Hausdorff dimension 1.
We show that the Texan Conjecture holds, i.e. for every t in1] there exists a
subsystem whose limit set has Hausdorff dimension t


title: External Fields as a Probe for Fundamental Physics

abstract:
  Quantum vacuum experiments are becoming a flexible tool for investigating
fundamental physics. They are particularly powerful for searching for new light
but weakly interacting degrees of freedom and are thus complementary to
accelerator-driven experiments. I review recent developments in this field,
focusing on optical experiments in strong electromagnetic fields. In order to
characterize potential optical signatures, I discuss various low-energy
effective actions which parameterize the interaction of particle-physics
candidates with optical photons and external electromagnetic fields.
Experiments with an electromagnetized quantum vacuum and optical probes do not
only have the potential to collect evidence for new physics, but
special-purpose setups can also distinguish between different particle-physics
scenarios and extract information about underlying microscopic properties.


title: Catalan numbers and power laws in cellular automaton rule 14

abstract:
  We discuss example of an elementary cellular automaton for which the density
of ones decays toward its limiting value as a power of the number of iterations
$n$. Using the fact that this rule conserves the number of blocks 10 and that
preimages of some other blocks exhibit patterns closely related to patterns
observed in rule 184, we derive expressions for the number of $n$-step
preimages of all blocks of length 3. These expressions involve Catalan numbers,
and together with basic properties of iterated probability measures they allow
us to to compute the density of ones after $n$ iterations, as well as
probabilities of occurrence of arbitrary block of length smaller or equal to 3.


title: Predictive pion-quark BCS relation and Thornber-Feynman high-Tc gap

abstract:
  A pion-quark pairing temperature is defined by a BCS-like relation identified
from a quark-level Goldberger-Treiman relation with a Nambu scalar mass "gap
parameter" taken in the low-mass limit. This intuitive relation predicts the
associated "experimental" lattice-gauge pairing temperature. The opposite
high-mass limit predicts the sigma mass, and notably has a predictive analog in
high-Tc superconductivity in the stable nondispersive energy gap as defined by
Thornber-Feynman polaron dynamics.


title: Spitzer imaging of the jet driving the NGC 2264 G outflow

abstract:
  We present new infrared imaging of the NGC 2264 G protostellar outflow
region, obtained with the InfraRed Array Camera (IRAC) on-board the Spitzer
Space Telescope. A jet in the red outflow lobe (eastern lobe) is clearly
detected in all four IRAC bands and, for the first time, is shown to
continuously extend over the entire length of the red outflow lobe traced by CO
observations. The redshifted jet also extends to a deeply embedded Class 0
source, VLA 2, confirming previous suggestions that it is the driving source of
the outflow (Gomez et al. 1994). The images show that the easternmost part of
the redshifted jet exhibits what appear to be multiple changes of direction. To
understand the redshifted jet morphology we explore several mechanisms that
could generate such apparent changes of direction. From this analysis, we
conclude that the redshifted jet structure and morphology visible in the IRAC
images can be largely, although not entirely, explained by a slowly precessing
jet (period ~8000 yr) that lies mostly on the plane of the sky. It appears that
the observed changes in the redshifted jet direction may be sufficient to
account for a significant fraction of the broadening of the outflow lobe
observed in the CO emission.


title: Electrostatics in wind-blown sand

abstract:
  Wind-blown sand, or "saltation," is an important geological process, and the
primary source of atmospheric dust aerosols. Significant discrepancies exist
between classical saltation theory and measurements. We show here that these
discrepancies can be resolved by the inclusion of sand electrification in a
physically based saltation model. Indeed, we find that electric forces enhance
the concentration of saltating particles and cause them to travel closer to the
surface, in agreement with measurements. Our results thus indicate that sand
electrification plays an important role in saltation.


title:
Light-Front Quantization of the Polyakov D1 Brane Action With a Scalar
  Dilaton Field

abstract:
  Light-front quantization of the conformally gauge-fixed Polyakov D1 brane
action with a scalar dilaton field is studied using the equal light-cone
world-sheet time framework.


title: Random subgroups of Thompson's group $F$

abstract:
  We consider random subgroups of Thompson's group $F$ with respect to two
natural stratifications of the set of all $k$ generator subgroups. We find that
the isomorphism classes of subgroups which occur with positive density are not
the same for the two stratifications.
  We give the first known examples of {\em persistent} subgroups, whose
isomorphism classes occur with positive density within the set of $k$-generator
subgroups, for all sufficiently large $k$. Additionally, Thompson's group
provides the first example of a group without a generic isomorphism class of
subgroup. Elements of $F$ are represented uniquely by reduced pairs of finite
rooted binary trees.
  We compute the asymptotic growth rate and a generating function for the
number of reduced pairs of trees, which we show is D-finite and not algebraic.
We then use the asymptotic growth to prove our density results.


title: Entanglement of subspaces in terms of entanglement of superpositions

abstract:
  We investigate upper and lower bounds on the entropy of entanglement of a
superposition of bipartite states as a function of the individual states in the
superposition. In particular, we extend the results in [G. Gour,
arxiv.org:0704.1521 (2007)] to superpositions of several states rather than
just two. We then investigate the entanglement in a subspace as a function of
its basis states: we find upper bounds for the largest entanglement in a
subspace and demonstrate that no such lower bound for the smallest entanglement
exists. Finally, we consider entanglement of superpositions using measures of
entanglement other than the entropy of entanglement.


title: FeynEdit - a tool for drawing Feynman diagrams

abstract:
  We describe the FeynEdit tool for drawing Feynman diagrams. Input and output
is done using the LaTeX macros of FeynArts, which also implies that diagrams
drawn by FeynArts can be edited with FeynEdit. The LaTeX code can be
conveniently transferred using copy-and-paste.


title: Seifert Fibered Spaces: Notes for a course given in the Spring of 1993

abstract:
  Notes for a one semester course. The notes contain a description of compact
three dimensional Seifert fibered spaces and a classification up to
homeomorphism of compact three dimensional Seifert fibered spaces with
non-empty boundary.


title:
A universal Dirac operator and noncommutative spin bundles over fuzzy
  complex projective spaces

abstract:
  We present a universal Dirac operator for noncommutative spin and spin^c
bundles over fuzzy complex projective spaces. We give an explicit construction
of these bundles, which are described in terms of finite dimensional matrices,
calculate the spectrum and explicitly exhibit the Dirac eigenspinors. To our
knowledge the spin^c spectrum for CP^n with n>=3 is new.


title: Regular cell complexes in total positivity

abstract:
  This paper proves a conjecture of Fomin and Shapiro that their combinatorial
model for any Bruhat interval is a regular CW complex which is homeomorphic to
a ball. The model consists of a stratified space which may be regarded as the
link of an open cell intersected with a larger closed cell, all within the
totally nonnegative part of the unipotent radical of an algebraic group. A
parametrization due to Lusztig turns out to have all the requisite features to
provide the attaching maps. A key ingredient is a new, readily verifiable
criterion for which finite CW complexes are regular involving an interplay of
topology with combinatorics.


title: Enumeration of number-conserving cellular automata rules with two inputs

abstract:
  We show that there exists a one-to-one correspondence between the set of
number-conserving cellular automata (CA) with $q$ inputs and the set of
balanced sequences with $q$ terms. This allows to enumerate number-conserving
CA. We also show that number-conserving rules are becoming increasingly rare as
the number of states increases.