title: The Intrinsic Fundamental Group of a Linear Category

abstract:
  We provide an intrinsic definition of the fundamental group of a linear
category over a ring as the automorphism group of the fibre functor on Galois
coverings. If the universal covering exists, we prove that this group is
isomorphic to the Galois group of the universal covering. The grading deduced
from a Galois covering enables us to describe the canonical monomorphism from
its automorphism group to the first Hochschild-Mitchell cohomology vector
space.


title:
Time-of-arrival probabilities and quantum measurements: II Application
  to tunneling times

abstract:
  We formulate quantum tunneling as a time-of-arrival problem: we determine the
detection probability for particles passing through a barrier at a detector
located a distance L from the tunneling region. For this purpose, we use a
Positive-Operator-Valued-Measure (POVM) for the time-of-arrival determined in
quant-ph/0509020 [JMP 47, 122106 (2006)]. This only depends on the initial
state, the Hamiltonian and the location of the detector. The POVM above
provides a well-defined probability density and an unambiguous interpretation
of all quantities involved. We demonstrate that for a class of localized
initial states, the detection probability allows for an identification of
tunneling time with the classic phase time. We also establish limits to the
definability of tunneling time.
  We then generalize these results to a sequential measurement set-up: the
phase space properties of the particles are determined by an unsharp sampling
before their attempt to cross the barrier. For such measurements the tunneling
time is defined as a genuine observable. This allows us to construct a
probability distribution for its values that is definable for all initial
states and potentials. We also identify a regime, in which these probabilities
correspond to a tunneling-time operator.


title: Fuzzy Scalar Field Theory as a Multitrace Matrix Model

abstract:
  We develop an analytical approach to scalar field theory on the fuzzy sphere
based on considering a perturbative expansion of the kinetic term. This
expansion allows us to integrate out the angular degrees of freedom in the
hermitian matrices encoding the scalar field. The remaining model depends only
on the eigenvalues of the matrices and corresponds to a multitrace hermitian
matrix model. Such a model can be solved by standard techniques as e.g. the
saddle-point approximation. We evaluate the perturbative expansion up to second
order and present the one-cut solution of the saddle-point approximation in the
large N limit. We apply our approach to a model which has been proposed as an
appropriate regularization of scalar field theory on the plane within the
framework of fuzzy geometry.


title: Kappa-symmetry for coincident D-branes

abstract:
  A kappa-symmetric action for coincident D-branes is presented. It is valid in
the approximation that the additional fermionic variables, used to incorporate
the non-abelian degrees of freedom, are treated classically. The action is
written as a Bernstein-Leites integral on the supermanifold obtained from the
bosonic worldvolume by adjoining the extra fermions. The integrand is a very
simple extension of the usual Green-Schwarz action for a single brane; all
symmetries, except for kappa, are manifest, and the proof of kappa-symmetry is
very similar to the abelian case.


title:
Fidelity susceptibility, scaling, and universality in quantum critical
  phenomena

abstract:
  We study fidelity susceptibility in one-dimensional asymmetric Hubbard model,
and show that the fidelity susceptibility can be used to identify the
universality class of the quantum phase transitions in this model. The critical
exponents are found to be 0 and 2 for cases of half-filling and away from
half-filling respectively.


title:
Time-of-arrival probabilities and quantum measurements: III Decay of
  unstable states

abstract:
  We study the decay of unstable states by formulating quantum tunneling as a
time-of-arrival problem: we determine the detection probability for particles
at a detector located a distance L from the tunneling region. For this purpose,
we use a Positive-Operator-Valued-Measure (POVM) for the time-of-arrival
determined in quant-ph/0509020 [JMP 7, 122106 (2006)]. This only depends on the
initial state, the Hamiltonian and the location of the detector. The POVM above
provides a well-defined probability density and an unambiguous interpretation
of all quantities involved. We demonstrate that the exponential decay only
arises if three specific mathematical conditions are met. Their physical
content is the following: (i) the decay time is much larger than any
microscopic timescale, so that the fine details of the initial state can be
ignored, (ii) there is no quantum coherence between the different `attempts' of
the particle to traverse the barrier, and (iii) the transmission probability
varies little within the momentum spread of the initial state. We also
determine the long time limits of the decay probability and we identify
regimes, in which the decays have no exponential phase.


title:
Robot motion planning, weights of cohomology classes, and cohomology
  operations

abstract:
  The complexity of algorithms solving the motion planning problem is measured
by a homotopy invariant TC(X) of the configuration space X of the system.
Previously known lower bounds for TC(X) use the structure of the cohomology
algebra of X. In this paper we show how cohomology operations can be used to
sharpen these lower bounds for TC(X). As an application of this technique we
calculate explicitly the topological complexity of various lens spaces. The
results of the paper were inspired by the work of E. Fadell and S. Husseini on
weights of cohomology classes appearing in the classical lower bounds for the
Lusternik - Schnirelmann category. In the appendix to this paper we give a very
short proof of a generalized version of their result.


title:
Decoherence in supernova neutrino transformations suppressed by
  deleptonization

abstract:
  In the dense-neutrino region at 50-400 km above the neutrino sphere in a
supernova, neutrino-neutrino interactions cause large flavor transformations.
We study when the multi-angle nature of the neutrino trajectories leads to
flavor decoherence between different angular modes. We consider a two-flavor
mixing scenario between nu_e and another flavor nu_x and assume the usual
hierarchy F(nu_e)>F{antinu_e)>F(nu_x)=F(antinu_x) for the number fluxes. We
define epsilon=(F(nu_e)-F(antinu_e))/(F(antinu_e)-F(antinu_x)) as a measure for
the deleptonization flux which is the one crucial parameter. The transition
between the quasi single-angle behavior and multi-angle decoherence is abrupt
as a function of epsilon. For typical choices of other parameters, multi-angle
decoherence is suppressed for epsilon>0.3, but a much smaller asymmetry
suffices if the neutrino mass hierarchy is normal and the mixing angle small.
The critical epsilon depends logarithmically on the neutrino luminosity. In a
realistic supernova scenario, the deleptonization flux is probably enough to
suppress multi-angle decoherence.


title: Alexander polynomials: Essential variables and multiplicities

abstract:
  We explore the codimension one strata in the degree-one cohomology jumping
loci of a finitely generated group, through the prism of the multivariable
Alexander polynomial. As an application, we give new criteria that must be
satisfied by fundamental groups of smooth, quasi-projective complex varieties.
These criteria establish precisely which fundamental groups of boundary
manifolds of complex line arrangements are quasi-projective. We also give sharp
upper bounds for the twisted Betti ranks of a group, in terms of multiplicities
constructed from the Alexander polynomial. For Seifert links in homology
3-spheres, these bounds become equalities, and our formula shows explicitly how
the Alexander polynomial determines all the characteristic varieties.


title:
Unusual temperature behavior of entropy of antiferromagnetic spin state
  in nuclear matter with effective finite range interaction

abstract:
  The unusual temperature behavior of the entropy of the antiferromagnetic
(AFM) spin state in symmetric nuclear matter with the Gogny D1S interaction,
being larger at low temperatures than the entropy of nonpolarized matter, is
related to the dependence of the entropy on the effective masses of nucleons in
a spin polarized state. The corresponding conditions for comparing the
entropies of the AFM and nonpolarized states in terms of the effective masses
are formulated, including low and high temperature limits. It is shown that the
unexpected temperature behavior of the entropy of the AFM spin state at low
temperatures is caused by the violation of the corresponding low temperature
criterium.


title:
Matching polytopes, toric geometry, and the non-negative part of the
  Grassmannian

abstract:
  In this paper we use toric geometry to investigate the topology of the
totally non-negative part of the Grassmannian (Gr_{kn})_{\geq 0}. This is a
cell complex whose cells Delta_G can be parameterized in terms of the
combinatorics of plane-bipartite graphs G. To each cell Delta_G we associate a
certain polytope P(G). The polytopes P(G) are analogous to the well-known
Birkhoff polytopes, and we describe their face lattices in terms of matchings
and unions of matchings of G. We also demonstrate a close connection between
the polytopes P(G) and matroid polytopes. We then use the data of P(G) to
define an associated toric variety X_G. We use our technology to prove that the
cell decomposition of (Gr_{kn})_{\geq 0} is a CW complex, and furthermore, that
the Euler characteristic of the closure of each cell of (Gr_{kn})_{\geq 0} is
1.


title: Metastable Flux Configurations and de Sitter Spaces

abstract:
  We derive stability conditions for the critical points of the no-scale scalar
potential governing the dynamics of the complex structure moduli and the
axio-dilaton in compactifications of type IIB string theory on Calabi-Yau
three-folds. We discuss a concrete example of a T^6 orientifold. We then
consider the four-dimensional theory obtained from compactifications of type
IIB string theory on non-geometric backgrounds which are mirror to rigid
Calabi-Yau manifolds and show that the complex structure moduli fields can be
stabilized in terms of H_{RR} only, i.e. with no need of orientifold
projection. The stabilization of all the fields at weak coupling, including the
axio-dilaton, may require to break supersymmetry in the presence of H_{NS} flux
or corrections to the scalar potential.


title: New Solutions of the Inflationary Flow Equations

abstract:
  The inflationary flow equations are a frequently used method of surveying the
space of inflationary models. In these applications the infinite hierarchy of
differential equations is truncated in a way which has been shown to be
equivalent to restricting the set of models considered to those characterized
by polynomial inflaton potentials. This paper explores a different method of
solving the flow equations, which does not truncate the hierarchy and in
consequence covers a much wider class of models while retaining the practical
usability of the standard approach.


title: Singular Sources of Energy in Stars and Planets

abstract:
  If primordial low-mass black holes (PBH) exist in the Universe than many of
stars and planetary bodies appear to be infected by them. This is also true in
regard to the Sun and likely Jupiter and Saturn. The availability of even the
very low-mass inner relativistic reactor may lead to essential changes in
evolution scenario of a celestial body on its lifetime scale. Black holes in
stellar interior may be found either in consequence of captures process or
incorporation during the formation of a star from interstellar clouds.
Surprisingly that in the equilibrium state a PBH growth is a long-lived process
with e-folding rise time of billion years. One can envision a PBH orbiting
inside the Sun. Our considerations showed that the PBH experiences very little
friction in passing through the stellar matter. If the BH mass is above
10^{-5}M_{sun} the major contribution to the luminosity comes from the
relativistic gravitational reactor. In such a case a star evolves towards the
Eddington limit. This should lead to considerable expansion of a star and a
global stability loss. Microscopic PBHs can exist in the interior of planetary
bodies too. To produce the required excess of thermal energy on Jupiter and
Saturn the masses of PBH captured are assumed to be reached of 4 10^{19} and 7
10^{18} g, respectively. These microscopic objects are comparable to the
hydrogen atom in size. One can envision even a planet with the PBH acting as
the self-sufficient source of heating. Such a planet does not need a sun to
maintain animal life on its surface. This may last eons.


title: Inert states of spin-S systems

abstract:
  We present a simple but efficient geometrical method for determining the
inert states of spin-S systems. It can be used if the system is described by a
spin vector of a spin-S particle and its energy is invariant in spin rotations
and phase changes. Our method is applicable to an arbitrary S and it is based
on the representation of a pure spin state of a spin-S particle in terms of 2S
points on the surface of a sphere. We use this method to find candidates for
some of the ground states of spinor Bose-Einstein condensates.


title: Varieties with very little transcendental cohomology

abstract:
  Given a complex algebraic variety X, we define a natural number called the
motivic dimension which measures the amount of transcendental (co)homology of
X. It is zero precisely when all the (co)homolgy is spanned by algebraic
cycles. Most of this paper is concerned with giving estimates on this number,
along with examples where it is small. As an application, we check or recheck
the Hodge conjectue in a number of examples: uniruled fourfolds, rationally
connected fivefolds, fourfolds fibred by surfaces with p_g=0, Hilbert schemes
of a small number points on surfaces with p_g=0, and generic hypersurfaces.


title: Adaptive homodyne phase discrimination and qubit measurement

abstract:
  Fast and accurate measurement is a highly desirable, if not vital, feature of
quantum computing architectures. In this work we investigate the usefulness of
adaptive measurements in improving the speed and accuracy of qubit measurement.
We examine a particular class of quantum computing architectures, ones based on
qubits coupled to well controlled harmonic oscillator modes (reminiscent of
cavity-QED), where adaptive schemes for measurement are particularly
appropriate. In such architectures, qubit measurement is equivalent to phase
discrimination for a mode of the electromagnetic field, and we examine adaptive
techniques for doing this. In the final section we present a concrete example
of applying adaptive measurement to the particularly well-developed circuit-QED
architecture.


title: Hardcore dimer aspects of the SU(2) Singlet wavefunction

abstract:
  We demonstrate that any SU(2) singlet wavefunction can be characterized by a
set of Valence Bond occupation numbers, testing dimer presence/vacancy on pairs
of sites. This genuine quantum property of singlet states (i) shows that SU(2)
singlets share some of the intuitive features of hardcore quantum dimers, (ii)
gives rigorous basis for interesting albeit apparently ill-defined quantities
introduced recently in the context of Quantum Magnetism or Quantum Information
to measure respectively spin correlations and bipartite entanglement and, (iii)
suggests a scheme to define consistently a wide family of quantities analogous
to high order spin correlation. This result is demonstrated in the framework of
a general functional mapping between the Hilbert space generated by an
arbitrary number of spins and a set of algebraic functions found to be an
efficient analytical tool for the description of quantum spins or qubits
systems.


title:
Exact Metric Operators as the Ground State functions of the Hermitian
  Conjugates of a Class of Quasi-Hermitian Hamiltonians

abstract:
  We generalized a class of non-Hermitian Hamiltonians which introduced
previously by us in such a way in which every member in the class is
non-\textit{PT}-symmetric. For every member of the class, the ground state is a
constant with zero energy eigen value. Instead of using an infinite set of
coupled operator equations to calculate the metric operator we used a simple
realization to obtain the class of closed form metric operators corresponding
to the class of non-Hermitian and non-\textit{PT}-symmetric Hamiltonians
introduced. The trick is that, if $\psi$ is an eigen function of $H$, then
$\phi=\eta\psi$ is an eigen function of $H^{\dagger}$ with the same eigen
value. Thus, knowing any pair $(\psi ,\phi)$ one can deduce the form of the
exact metric operator. We note that, the class of Hamiltonians generalized in
this work has the form of that of imaginary magnetic field which can be
absorbed by the quasi-gauge transformations represented by metric operators.
Accordingly, it is expected that the $Q$ operators will disappear for the whole
members in the class in the path integral formulation. However, the detailed
analysis of this issue will appear in another work.


title:
Arrival time distribution for a driven system containing quenched
  dichotomous disorder

abstract:
  We study the arrival time distribution of overdamped particles driven by a
constant force in a piecewise linear random potential which generates the
dichotomous random force. Our approach is based on the path integral
representation of the probability density of the arrival time. We explicitly
calculate the path integral for a special case of dichotomous disorder and use
the corresponding characteristic function to derive prominent properties of the
arrival time probability density. Specifically, we establish the scaling
properties of the central moments, analyze the behavior of the probability
density for short, long, and intermediate distances. In order to quantify the
deviation of the arrival time distribution from a Gaussian shape, we evaluate
the skewness and the kurtosis.


title: Chaos in Kundt type III Spacetimes

abstract:
  We consider geodesics motion in a particular Kundt type III spacetime in
which Einstein-Yang-Mills equations admit solutions. On a particular surface as
constraint we project the geodesics into the (x,y) plane and treat the problem
as a 2-dimensional one. Our numerical study shows that chaotic behavior emerges
under reasonable conditions.


title:
Logarithmic comparison theorem versus Gauss-Manin system for isolated
  singularities

abstract:
  For quasihomogeneous isolated hypersurface singularities, the logarithmic
comparison theorem has been characterized explicitly by Holland and Mond. In
the non quasihomogeneous case, we give a necessary condition for the
logarithmic comparison theorem in terms of the Gauss-Manin system of the
singularity. It shows in particular that the logarithmic comparison theorem can
hold for a non quasihomogeneous singularity only if 1 is an eigenvalue of the
monodromy.


title: The Harmonic Series and the nth Term Test for Divergence

abstract:
  The divergence of the harmonic series is proved by direct comparison with a
series whose nth partial sum telescopes to the natural logarithm of n. The key
idea is to apply the classical inequality x>=log(1+x) (valid for x>-1) with
x=1/k and sum over k, 1<=k<=n-1.


title:
Simple proof of gauge invariance for the S-matrix element of
  strong-field photoionization

abstract:
  The relationship between the length gauge (LG) and the velocity gauge (VG)
exact forms of the photoionization probability amplitude is considered. Our
motivation for this paper comes from applications of the Keldysh-Faisal-Reiss
(KFR) theory, which describes atoms (or ions) in a strong laser field (in the
nonrelativistic approach, in the dipole approximation). On the faith of a
certain widely-accepted assumption, we present a simple proof that the
well-known LG form of the exact photoionization (or photodetachment)
probability amplitude is indeed the gauge-invariant result. In contrast, to
obtain the VG form of this probability amplitude, one has to either (i) neglect
the well-known Goeppert-Mayer exponential factor (which assures gauge
invariance) during all the time evolution of the ionized electron or (ii) put
some conditions on the vector potential of the laser field.


title: Canonical Melnikov theory for diffeomorphisms

abstract:
  We study perturbations of diffeomorphisms that have a saddle connection
between a pair of normally hyperbolic invariant manifolds. We develop a
first-order deformation calculus for invariant manifolds and show that a
generalized Melnikov function or Melnikov displacement can be written in a
canonical way. This function is defined to be a section of the normal bundle of
the saddle connection.
  We show how our definition reproduces the classical methods of Poincar\'{e}
and Melnikov and specializes to methods previously used for exact symplectic
and volume-preserving maps. We use the method to detect the transverse
intersection of stable and unstable manifolds and relate this intersection to
the set of zeros of the Melnikov displacement.


title: Reconstructing pedigrees: a stochastic perspective

abstract:
  A pedigree is a directed graph that describes how individuals are related
through ancestry in a sexually-reproducing population. In this paper we explore
the question of whether one can reconstruct a pedigree by just observing
sequence data for present day individuals. This is motivated by the increasing
availability of genomic sequences, but in this paper we take a more theoretical
approach and consider what models of sequence evolution might allow pedigree
reconstruction (given sufficiently long sequences). Our results complement
recent work that showed that pedigree reconstruction may be fundamentally
impossible if one uses just the degrees of relatedness between different extant
individuals. We find that for certain stochastic processes, pedigrees can be
recovered up to isomorphism from sufficiently long sequences.


title:
Big-Pieces-of-Lipschitz-Images Implies a Sufficient Carleson Estimate in
  a Metric Space

abstract:
  This note is intended to be a supplement to the bi-Lipschitz decomposition of
Lipschitz maps shown in [Sch]. We show that in the case of 1-Ahlfors-regular
sets, the condition of having `Big Pieces of bi-Lipschitz Images' (BPBI) is
equivalent to a Carleson condition.


title:
Single nitrogen vacancy centers in chemical vapor deposited diamond
  nanocrystals

abstract:
  Nanodiamond crystals containing single color centers have been grown by
chemical vapor deposition (CVD). The fluorescence from individual crystallites
was directly correlated with crystallite size using a combined atomic force and
scanning confocal fluorescence microscope. Under the conditions employed, the
optimal size for single optically active nitrogen-vacancy (NV) center
incorporation was measured to be 60 to 70 nm. The findings highlight a strong
dependence of NV incorporation on crystal size, particularly with crystals less
than 50 nm in size.


title:
Chandra Observation of the Cluster Environment of a WAT Radio Source in
  Abell 1446

abstract:
  Wide-angle tail (WAT) radio sources are often found in the centers of galaxy
clusters where intracluster medium (ICM) ram pressure may bend the lobes into
their characteristic C-shape. We examine the low redshift (z=0.1035) cluster
Abell 1446, host to the WAT radio source 1159+583. The cluster exhibits
possible evidence for a small-scale cluster-subcluster merger as a cause of the
WAT radio source morphology. This evidence includes the presence of temperature
and pressure substructure along the line that bisects the WAT as well as a
possible wake of stripped interstellar material or a disrupted cool core to the
southeast of the host galaxy. A filament to the north may represent cool,
infalling gas that's contributing to the WAT bending while spectroscopically
determined redshifts of member galaxies may indicate some component of a merger
occurring along the line-of-sight. The WAT model of high flow velocity and low
lobe density is examined as another scenario for the bending of 1159+583. It
has been argued that such a model would allow the ram pressure due to the
galaxy's slow motion through the ICM to shape the WAT source. A temperature
profile shows that the cluster is isothermal (kT= 4.0 keV) in a series of
annuli reaching a radius of 400 kpc. There is no evidence of an ongoing cooling
flow. Temperature, abundance, pressure, density, and mass profiles, as well as
two-dimensional maps of temperature and pressure are presented.


title:
Analysis of Inter-Domain Traffic Correlations: Random Matrix Theory
  Approach

abstract:
  The traffic behavior of University of Louisville network with the
interconnected backbone routers and the number of Virtual Local Area Network
(VLAN) subnets is investigated using the Random Matrix Theory (RMT) approach.
We employ the system of equal interval time series of traffic counts at all
router to router and router to subnet connections as a representation of the
inter-VLAN traffic. The cross-correlation matrix C of the traffic rate changes
between different traffic time series is calculated and tested against
null-hypothesis of random interactions.
  The majority of the eigenvalues \lambda_{i} of matrix C fall within the
bounds predicted by the RMT for the eigenvalues of random correlation matrices.
The distribution of eigenvalues and eigenvectors outside of the RMT bounds
displays prominent and systematic deviations from the RMT predictions.
Moreover, these deviations are stable in time.
  The method we use provides a unique possibility to accomplish three
concurrent tasks of traffic analysis. The method verifies the uncongested state
of the network, by establishing the profile of random interactions. It
recognizes the system-specific large-scale interactions, by establishing the
profile of stable in time non-random interactions. Finally, by looking into the
eigenstatistics we are able to detect and allocate anomalies of network traffic
interactions.


title: Material-Point Simulation to Cavity Collapse Under Shock

abstract:
  The collapse of cavities under shock is a key problem in various fields
ranging from erosion of material, ignition of explosive, to sonoluminescence,
etc. We study such processes using the material-point-method developed recently
in the field of solid physics. The main points of the research include the
relations between symmetry of collapsing and the strength of shock, other
coexisting interfaces, as well as hydrodynamic and thermal-dynamic behaviors
ignored by the pure fluid models. In the case with strong shock, we study the
procedure of jet creation in the cavity; in the case with weak shock, we found
that the cavity can not be collapsed completely by the shock and the cavity may
collapse in a nearly isotropic way. The history of collapsing significantly
influences the distribution of "hot spots" in the shocked material. The change
in symmetry of collapsing is investigated. Since we use the Mie-Gr% \"{u}neisen
equation of state and the effects of strain rate are not taken into account,
the behavior is the same if one magnifies the spatial and temporal scales in
the same way.


title: Grounding Bohmian Mechanics in Weak Values and Bayesianism

abstract:
  Bohmian mechanics (BM) is a popular interpretation of quantum mechanics in
which particles have real positions. The velocity of a point x in configuration
space is defined as the standard probability current j(x) divided by the
probability density P(x). However, this ``standard'' j is in fact only one of
infinitely many that transform correctly and satisfy \dot P + \del . j=0. In
this article I show that there is a unique j that can be determined
experimentally as a weak value using techniques that would make sense to a
classical physicist. Moreover, this operationally defined j equals the standard
j, so, assuming \dot x = j/P, the possible Bohmian paths can also be determined
experimentally from a large enough ensemble. Furthermore, this approach to
deriving BM singles out x as the hidden variable, because (for example) the
operationally defined momentum current is in general incompatible with the
evolution of the momentum distribution. Finally I discuss how, in this setting,
the usual quantum probabilities can be derived from a Bayesian standpoint, via
the principle of indifference.


title:
An in-medium full-folding model approach to quasielastic (p,n)
  charge-exchange reactions

abstract:
  A microscopic description of the quasielastic (p,n) charge-exchange reaction
(here, charge-exchange scattering between analogue states) is presented and
discussed. Emphasis is focused on the spin-isospin structure of the
projectile-target coupling. The model is a coupled-channel extension of the
full-folding optical model approach (OMP) developed for nucleon elastic
scattering, where emphasis is placed on retaining the genuine off-shell
behavior of realistic effective interactions in the nuclear medium. The
resulting non-local optical potentials are applied to the calculation of (p,n)
differential cross sections, with particular emphasis on small-angle Fermi
($\Delta S=0$) cross-sections to isobaric analog states. These parameter-free
results provide a reasonable description of the $^{14}$C(p,n)-data at proton
energies above $\sim$100 MeV, but deteriorate for heavier targets. These
shortcomings are analyzed and possible ways to correct them are discussed.


title: Magnetic Excitations in NpCoGa5

abstract:
  We report the results of inelastic neutron scattering experiments on
NpCoGa$_{5}$, an isostructural analogue of the PuCoGa$_{5}$ superconductor. Two
energy scales characterize the magnetic response in the antiferromagnetic
phase. One is related to a non-dispersive excitation between two crystal field
levels. The other at lower energies corresponds to dispersive fluctuations
emanating from the magnetic zone center. The fluctuations persist in the
paramagnetic phase also, although weaker in intensity. This supports the
possibility that magnetic fluctuations are present in PuCoGa$_{5}$, where
unconventional d-wave superconductivity is achieved in the absence of magnetic
order.


title: Deconfinement phase transition in holographic QCD with matter

abstract:
  In the framework of a holographic QCD approach we study an influence of
matters on the deconfinement temperature, $T_c$. We first consider quark flavor
number ($N_f$) dependence of $T_c$. We observe that $T_c$ decreases with $N_f$,
which is consistent with a lattice QCD result. We also delve into how the quark
number density $\rho_q$ affects the value of $T_c$. We find that $T_c$ drops
with increasing $\rho_q$. In both cases, we confirm that the contributions from
quarks are suppressed by $1/N_c$, as it should be, compared to the ones from a
gravitational action (pure Yang-Mills).


title: Potential inversion with subbarrier fusion data revisited

abstract:
  We invert experimental data for heavy-ion fusion reactions at energies well
below the Coulomb barrier in order to directly determine the internucleus
potential between the colliding nuclei. In contrast to the previous
applications of the inversion formula, we explicitly take into account the
effect of channel couplings on fusion reactions, by assuming that fusion cross
sections at deep subbarrier energies are governed by the lowest barrier in the
barrier distribution. We apply this procedure to the $^{16}$O +$^{144}$Sm and
$^{16}$O +$^{208}$Pb reactions, and find that the inverted internucleus
potential are much thicker than phenomenological potentials. A relation to the
steep fall-off phenomenon of fusion cross sections recently found at deep
subbarrier energies is also discussed.


title:
Effects of Magnetic Fields on Neutrino-dominated Accretion Model for
  Gamma-ray Bursts

abstract:
  Many models of gamma-ray bursts suggest a common central engine: a black hole
of several solar masses accreting matter from a disk at an accretion rate from
0.01 to 10 M_\sun / s. The inner region of the disk is cooled by neutrino
emission and large amounts of its binding energy were liberated, which could
trigger the fireball. We improve the neutrino-dominated accreting flows by
considering the effects of the magnetic fields, and find that more than half of
the liberating energy can be extracted directly by the large-scale magnetic
fields on the disk. And it turns out that the temperature of the disk is a bit
lower than the neutrino-dominated accreting flows without magnetic field.
Therefore, The outflows are magneticallydominated rather than neutrino
dominated. In our model, neutrino mechanism can fuel some GRBs (not the
brightest ones), but cannot fuel X-ray flares. However, the magnetic processes
(both BZ and electromagnetic luminosity from a disk) are viable mechanisms for
most of GRBs and the following X-ray flares.


title:
Electron-Electron Interactions on the Edge States of Graphene: A Many
  Body Configuration Interaction Study

abstract:
  We have studied zigzag and armchair graphene nano ribbons (GNRs), described
by the Hubbard Hamiltonian using quantum many body configuration interaction
methods. Due to finite termination, we find that the bipartite nature of the
graphene lattice gets destroyed at the edges making the ground state of the
zigzag GNRs a high spin state, whereas the ground state of the armchair GNRs
remains a singlet. Our calculations of charge and spin densities suggest that,
although the electron density prefers to accumulate on the edges, instead of
spin polarization, the up and down spins prefer to mix throughout the GNR
lattice. While the many body charge gap results in insulating behavior for both
kinds of GNRs, the conduction upon application of electric field is still
possible through the edge channels because of their high electron density.
Analysis of optical states suggest differences in quantum efficiency of
luminescence for zigzag and armchair GNRs, which can be probed by simple
experiments.


title:
Compact lattice formulation of Cho-Faddeev-Niemi decomposition: gluon
  mass generation and infrared Abelian dominance

abstract:
  This paper complements a new lattice formulation of SU(2) Yang-Mills theory
written in terms of new variables in a compact form proposed in the previous
paper. The new variables used in the formulation were once called the
Cho--Faddeev--Niemi or Cho--Faddeev--Niemi--Shabanov decomposition. Our
formulation enables us to explain the infrared ``Abelian'' dominance, in
addition to magnetic monopole dominance shown in the previous paper, in the
gauge invariant way without relying on the specific gauge fixing called the
maximal Abelian gauge used in the conventional investigations. In this paper,
especially, we demonstrate by numerical simulations that gluon degrees of
freedom other than the ``Abelian'' part acquire the mass to be decoupled in the
low-energy region leading to the infrared Abelian dominance.


title: Newton-Hodge Filtration for Self-Dual F-Crystals

abstract:
  In this paper we study F-crystals with self-dual structure over base schemes
of characteristic p. We generalize Katz's Newton-Hodge Filtration Theorem to
F-crystals with self-dual structure.


title: R-Parity Violation and Family Symmetry

abstract:
  In this talk, we investigate the implications of R-parity violating (RPV)
operators in a model with family symmetry. Family symmetry can determine the
form of RPV operators as well as the Yukawa matrices. We consider a concrete
model with non-abelian discrete symmetry Q_6, which has only three RPV
trilinear operators with no baryon number violating terms. We find that ratios
of decay rates of the lepton flavor violating processes are fixed thanks to the
family symmetry, predicting BR(tau to 3e)/BR(tau to 3mu) ~ 4
m_{mu}^2/m_{tau}^2.


title: Neutrino symmetries from high to low scales

abstract:
  Proposed symmetry relations, e.g., quark-lepton complementarity (QLC) or
tribimaximal mixing (TBM), need to be imposed at a high scale $\wedge \sim
10^{12}$ GeV characterising the large masses of right-handed neutrinos required
to implement the seesaw mechanism. RG evolution down to the laboratory scale
$\lambda \sim 10^3$ GeV, generically prone to spoil these relations and their
predicted neutrino mixing patterns, can be made to preserve them by
appropriately constraining the Majorana phases $\alpha_{2,3}$. This is
explicitly demonstrated in the MSSM for two versions of QLC and two versions of
TBM. A preference for $\alpha_2 \simeq \pi$ (i.e. $m_1 \simeq - m_2$) emerges
in each case. Discrimination among the four cases is shown to be possible by
future measurements of $\theta_{13}$.


title:
Weak phase information from the color suppressed B_d^0 -> D^{*0} K^{*0}
  modes

abstract:
  The decay channels $B_d^0 \to D^{*0} K^{*0}$ are investigated for extracting
weak $CKM$ phase information. These channels are described by color-suppressed
tree diagrams only and are free from penguin contributions. The branching
ratios for these channels are found to be $\sim \cal O $ $(10^{-5} - 10^{-6})$
which can be measured at the currently running $B$ factories. The method
presented here may be well-suited to determine the phase $\gamma$.


title: Charged Lepton Mass Formula -- Development and Prospect --

abstract:
  The recent devolopment on the charged lepton mass forumula
m_e+m_{\mu}+m_{\tau}={2/3}(\sqrt{m_e}+\sqrt{m_\mu}+\sqrt{m_{\tau}})^2 is
reviewed. An S_3 or A_4 model will be promising for the mass relation.


title: Optical Marking of Alcohol Induced Hemoglobin Modification

abstract:
  It has been shown that conformational modifications of Hb induced by ethanol
consumption can be visualized in optical spectra studying oxygenation kinetics
of hemoglobin or mixing hemoglobin with Cibacron blue dye. Better dye affinity
of blood proteins extracted from alcoholised rats with respect to those from
non-alcoholised ones confirms that ethanol and its metabolites induce
structural pathologies in blood protein molecules. The detected changes for the
case of the posterity of intoxicated animals may be explained as a
post-translation modification, as well as a disturbance of the structure and
function of tissue cellular gene mechanism for the blood creation. It is
established that alcohol intake during first four months leads to the decrease
of fractional weight of oxyhemoglobin and to the increase of methemoglobin
amount in blood. Further alcohol consumption is accompanied by recovering of
the normal level of hemoglobin derivatives in blood. Normalization of the
fractional weight of hemoglobin derivatives in blood after durable (longer than
5-6 months) ethanol intoxication is most probably due to the activation of the
enzyme (acetaldehyde dehydrogenase) system, lowering the level of acetaldehydes
in blood.


title:
Exact wave-packet decoherence dynamics in a discrete spectrum
  environment

abstract:
  We find an exact analytical solution of the reduced density matrix from the
Feynman-Vernon influence functional theory for a wave packet influenced by an
environment containing a few discrete modes. We obtain two intrinsic energy
scales relating to the time scales of the system and the environment. Different
relationship between these two scales alters the overall form of the solution
of the system. We also introduce a decoherence measure for a single wave packet
which is defined as the ratio of Schr\"odinger uncertainty over the
delocalization extension of the wave packet and characterizes the
time-evolution behavior of the off-diagonal reduced density matrix element. We
utilize the exact solution and the docherence measure to study the wave packet
decoherence dynamics. We further demonstrate how the dynamical diffusion of the
wave packet leads to non-Markovian decoherence in such a microscopic
environment.


title:
One-Range Addition Theorems in Terms of -ETOs for STOs and
  Coulomb-Yukawa Like Correlated Interaction Potentials of Integer and
  Noninteger Indices

abstract:
  In this study, the one-center expansion formulas in terms of complete
orthonormal sets of -exponential type orbitals (-ETOs,) are established for the
Slater type orbitals (STOs) and Coulomb-Yukawa like correlated interaction
potentials (CIPs) of integer and noninteger indices. These relations are used
in obtaining the unsymmetrical and symmetrical one-range addition theorems for
STOs and Coulomb-Yukawa like CIPs. The final results are especially useful in
the calculations of multicenter multielectron integrals of STOs and CIPs
occurring when Hartree-Fock-Roothaan (HFR) and explicitly correlated method are
employed.


title:
Bose-Einstein Correlations of Charged and Neutral Kaons in Deep
  Inelastic Scattering at HERA

abstract:
  Bose-Einstein correlations of charged and neutral kaons have been measured in
e+-p deep inelastic scattering with an integrated luminosity of 121 pb-1 using
the ZEUS detector at HERA. The two-particle correlation function was studied as
a function of the four-momentum difference of the kaon pairs,
Q_12=sqrt{-(p_1-p_2)^2}, assuming a Gaussian shape for the particle source. The
values of the radius of the production volume, r, and of the correlation
strength, lambda, were obtained for both neutral and charged kaons. The radii
for charged and neutral kaons are similar and are consistent with those
obtained at LEP.


title: Many body localization in Heisenberg XXZ magnet in a random field

abstract:
  We numerically investigate Heisenberg XXZ spin-1/2 chain in a spatially
random static magnetic field. We find that tDMRG simulations of time evolution
can be performed efficiently, namely the dimension of matrices needed to
efficiently represent the time-evolution increases linearly with time and
entanglement entropies for typical chain bipartitions increase logarithmically.
As a result, we show that for large enough random fields infinite temperature
spin-spin correlation function displays exponential localization in space
indicating insulating behavior of the model.


title: Pomeron loop and running coupling effects in high energy QCD evolution

abstract:
  Within the framework of a (1+1)-dimensional model which mimics evolution and
scattering in QCD at high energy, we study the influence of the running of the
coupling on the high-energy dynamics with Pomeron loops. We find that the
particle number fluctuations are strongly suppressed by the running of the
coupling, by at least one order of magnitude as compared to the case of a fixed
coupling, for all the rapidities that we have investigated, up to Y=200. This
reflects the slowing down of the evolution by running coupling effects, in
particular, the large rapidity evolution which is required for the formation of
the saturation front via diffusion. We conclude that, for all energies of
interest, processes like deep inelastic scattering or forward particle
production can be reliably studied within the framework of a mean-field
approximation (like the Balitsky-Kovchegov equation) which includes running
coupling effects.


title: Binary Black Holes: Spin Dynamics and Gravitational Recoil

abstract:
  We present a study of spinning black hole binaries focusing on the spin
dynamics of the individual black holes as well as on the gravitational recoil
acquired by the black hole produced by the merger. We consider two series of
initial spin orientations away from the binary orbital plane. In one of the
series, the spins are anti-aligned; for the second series, one of the spins
points away from the binary along the line separating the black holes. We find
a remarkable agreement between the spin dynamics predicted at 2nd
post-Newtonian order and those from numerical relativity. For each
configuration, we compute the kick of the final black hole. We use the kick
estimates from the series with anti-aligned spins to fit the parameters in the
\KKF{,} and verify that the recoil along the direction of the orbital angular
momentum is $\propto \sin\theta$ and on the orbital plane $\propto \cos\theta$,
with $\theta$ the angle between the spin directions and the orbital angular
momentum. We also find that the black hole spins can be well estimated by
evaluating the isolated horizon spin on spheres of constant coordinate radius.


title:
Understanding of complex periodic transformations of moving domain walls
  in magnetic nanostripes

abstract:
  The magnetic field (or electric current) driven domain-wall motion in
magnetic nanostripes is of considerable interest because it is essential to the
performance of information storage and logic devices. One of the currently key
problems is to unveil the complex behaviors of oscillatory domain-wall motions
under applied magnetic fields stronger than the so-called Walker field, beyond
which the velocity of domain walls markedly drops. Here, we provide not only
considerably better understandings but also new details of the complex
domain-wall motions. In a certain range just above the Walker field, the
motions are not chaotic but rather periodic with different unique periodicities
of dynamic transformations of a moving domain wall between the different types
of its internal structure. Three unique periodicities found, which consist of
different types of domain wall that are transformed from type one to another.
The transformation periods vary with the field strength and the nanostripe
width. This novel phenomenon can be described by the dynamic motion of a
limited number of magnetic topological solitons such as vortex and antivortex
in nanostripes.


title: Dirac Equation in the Background of the Nutku Helicoid Metric

abstract:
  We study the solutions of the Dirac equation in the background of the Nutku
helicoid metric. This metric has curvature singularities, which necessitates
imposing a boundary to exclude this point. We use the Atiyah-Patodi-Singer non
local spectral boundary conditions for both the four and the five dimensional
manifolds.


title: Abstract machines for dialogue games

abstract:
  The notion of abstract Boehm tree has arisen as an operationally-oriented
distillation of works on game semantics, and has been investigated in two
papers. This paper revisits the notion, providing more syntactic support and
more examples (like call-by-value evaluation) illustrating the generality of
the underlying computing device. Precise correspondences between various
formulations of the evaluation mechanism of abstract Boehm trees are
established.


title:
Factorization and Gauge Invariance of Twist-3 Cross Section for Single
  Spin Asymmetry

abstract:
  We prove factorization and gauge invariance of the twist-3
single-spin-dependent cross section in the leading order perturbative QCD,
which was missing in the previous literature. We emphasize that the consistency
relation from the Ward identities for color gauge invariance is crucial to
guarantee the cancelation among the various gauge-noninvariant contributions in
the cross section. This relation also proves the absence of the "derivative"
terms in the cross section corresponding to the hard-pole and soft-fermion-pole
contributions. Applying the formalism to SIDIS, $ep^\uparrow\to e\pi X$, we
have derived the complete cross section associated with the twist-3
distribution for the transversely polarized nucleon.


title: Kink Confinement and Supersymmetry

abstract:
  We analyze non-integrable deformations of two-dimensional N=1 supersymmetric
quantum field theories with kink excitations. As example, we consider the
multi-frequency Super Sine Gordon model. At weak coupling, this model is robust
with respect to kink confinement phenomena, in contrast to the purely bosonic
case. If we vary the coupling, the model presents a sequence of phase
transitions, where pairs of kinks disappear from the spectrum. The phase
transitions fall into two classes: the first presents the critical behaviors of
the Tricritical Ising model, the second instead those of the gaussian model. In
the first case, close to the critical point, the model has metastable vacua,
with a spontaneously supersymmetry breaking. When the life-time of the
metastable vacua is sufficiently long, the role of goldstino is given by the
massless Majorana fermion of the Ising model. On the contrary, supersymmetry
remains exact in the phase transition of the second type.


title:
Swift-XRT observation of 34 new INTEGRAL/IBIS AGNs: discovery of Compton
  thick and other peculiar sources

abstract:
  For a significant number of the sources detected at high energies (>10 keV)
by the INTEGRAL/IBIS and Swift/BAT instruments there is either a lack
information about them in the 2-10 keV range or they are totally unidentified.
Herein, we report on a sample of 34 IBIS AGN or AGN candidate objects for which
there is X-ray data in the Swift/XRT archive. Thanks to these X-ray follow up
observations, the identification of the gamma ray emitters has been possible
and the spectral shape in terms of photon index and absorption has been
evaluated for the first time for the majority of our sample sources. The
sample, enlarged to include 4 more AGN already discussed in the literature, has
been used to provide photon index and column density distribution. We obtain a
mean value of 1.88 with a dispersion of 0.12, i.e. typical of an AGN sample.
Sixteen objects (47%) have column densities in excess of 10^{22} cm^{-2} and,
as expected, a large fraction of the absorbed sources are within the Sey 2
sample. We have provided a new diagnostic tool (NH versus
F(2-10)keV/F(20-100)keV softness ratio) to isolate peculiar objects; we find at
least one absorbed Sey 1 galaxy, 3 Compton thick AGN candidates; and one secure
example of a "true" type 2 AGN. Within the sample of 10 still unidentified
objects, 3 are almost certainly AGN of type 2; 3 to 4 have spectral slopes
typical of AGN; and two are located high on the galactic plane and are strong
enough radio emitters so that can be considered good AGN candidates.


title: WSRT Faraday tomography of the Galactic ISM at \lambda \sim 0.86 m

abstract:
  We investigate the distribution and properties of Faraday rotating and
synchrotron emitting regions in the Galactic ISM in the direction of the
Galactic anti-centre. We apply Faraday tomography to a radio polarization
dataset that we obtained with the WSRT. We developed a new method to calculate
a linear fit to periodic data, which we use to determine rotation measures from
our polarization angle data. From simulations of a Faraday screen + noise we
could determine how compatible the data are with Faraday screens. An
unexpectedly large fraction of 14% of the lines-of-sight in our dataset show an
unresolved main component in the Faraday depth spectrum. For lines-of-sight
with a single unresolved component we demonstrate that a Faraday screen in
front of a synchrotron emitting region that contains a turbulent magnetic field
component can explain the data.


title:
A statistical mechanics approach to reverse engineering: sparsity and
  biological priors on gene regulatory networks

abstract:
  The important task of determining the connectivity of gene networks, and at a
more detailed level even the kind of interaction existing between genes, can
nowadays be tackled by microarraylike technologies. Yet, there is still a large
amount of unknowns with respect to the amount of data provided by a single
microarray experiment, and therefore reliable gene network retrieval procedures
must integrate all of the available biological knowledge, even if coming from
different sources and of different nature. In this paper we present a reverse
engineering algorithm able to reveal the underlying gene network by using
time-series dataset on gene expressions considering the system response to
different perturbations. The approach is able to determine the sparsity of the
gene network, and to take into account possible {\it a priori} biological
knowledge on it. The validity of the reverse engineering approach is
highlighted through the deduction of the topology of several {\it simulated}
gene networks, where we also discuss how the performance of the algorithm
improves enlarging the amount of data or if any a priori knowledge is
considered. We also apply the algorithm to experimental data on a nine gene
network in {\it Escherichia coli


title: Entanglement swapping in a Franson interferometer setup

abstract:
  We propose a simple scheme to swap the non local correlations, characteristic
of a Franson interferometric setup, between pairs of frequency entangled
photons emitted by distinct non linear crystals in a parametric down conversion
process. Our scheme consists of two distinct sources of frequency entangled
photons. One photon of each pair is sent to a separate Mach - Zender
interferometer while the other photons of the pairs are mixed by a beam
splitter and then detected in a Ou - Mandel interferometer. For suitably
postselected joint measuremetns, the photons sent at the Mach -Zender show a
coincidence photocount statistics which depends non locally on the settings of
the two interferometers.


title:
The Dependence of Galaxy Formation on Cosmological Parameters: Can we
  distinguish the WMAP1 and WMAP3 Parameter Sets?

abstract:
  We combine N-body simulations of structure growth with physical modelling of
galaxy evolution to investigate whether the shift in cosmological parameters
between the 1-year and 3-year results from the Wilkinson Microwave Anisotropy
Probe affects predictions for the galaxy population. Structure formation is
significantly delayed in the WMAP3 cosmology, because the initial matter
fluctuation amplitude is lower on the relevant scales. The decrease in dark
matter clustering strength is, however, almost entirely offset by an increase
in halo bias, so predictions for galaxy clustering are barely altered. In both
cosmologies several combinations of physical parameters can reproduce observed,
low-redshift galaxy properties; the star formation, supernova feedback and AGN
feedback efficiencies can be played off against each other to give similar
results. Models which fit observed luminosity functions predict projected
2-point correlation functions which scatter by about 10-20 per cent on large
scale and by larger factors on small scale, depending both on cosmology and on
details of galaxy formation. Measurements of the pairwise velocity distribution
prefer the WMAP1 cosmology, but careful treatment of the systematics is needed.
Given current modelling uncertainties, it is not easy to distinguish the WMAP1
and WMAP3 cosmologies on the basis of low-redshift galaxy properties. Model
predictions diverge more dramatically at high redshift. Better observational
data at z>2 will better constrain galaxy formation and perhaps also
cosmological parameters.


title:
The noncommutative residue and canonical trace in the light of Stokes'
  and continuity properties

abstract:
  We show that the noncommutative residue density, resp. the cut-off
regularised integral are the only closed linear, resp. continuous closed linear
forms on certain classes of symbols. This leads to alternative proofs of the
uniqueness of the noncommutative residue, resp. the canonical trace as linear,
resp. continuous linear forms on certain classes of classical
pseudodifferential operators which vanish on brackets. The uniqueness of the
canonical trace actually holds on classes of classical pseudodifferential with
vanishing residue density which include non integer order operators in all
dimensions and odd-class (resp. even-class) operators in odd (resp. even)
dimensions. The description of the canonical trace for non integer order
operators as an integrated global density on the manifold is extended to
odd-class (resp. even-class) operators in odd (resp. even) dimensions on the
grounds of defect formulae for regularised traces of classical
pseudodifferential operators.


title:
Asymptotic freedom and quarks confinement treated through Thompson's
  approach

abstract:
  In this work, we first use Thompson's renormalization group method to treat
QCD-vacuum behavior close to the regime of asymptotic freedom. QCD-vacuum
behaves effectively like a "paramagnetic system" of a classical theory in the
sense that virtual color charges (gluons) emerge in it as spin effect of a
paramagnetic material when a magnetic field aligns their microscopic magnetic
dipoles. Making a classical analogy with the paramagnetism of Landau's
theory,we are able to introduce a kind of Landau effective action without
temperature and phase transition for simply representing QCD-vacuum behavior at
higher energies as magnetization of a paramagnetic material in the presence of
a magnetic field H. This reasoning allows us to use Thompson's heuristic
approach in order to extract an "effective susceptibility" ($\chi>0$) of
QCD-vacuum. It depends on logarithmic of energy scale u to investigate hadronic
matter. Consequently,we are able to get an "effective magnetic permeability"
($\mu>1$) of such a "paramagnetic vacuum". As QCD-vacuum must obey Lorentz
invariance,the attainment of $\mu>1$ must simply require that the "effective
electrical permissivity" is $\epsilon<1$,in such a way that $\mu\epsilon=1$
(c^2=1).This leads to the antiscreening effect, where the asymptotic freedom
takes place. On the other hand, quarks cofinement, a subject which is not
treatable by perturbative calculations, is worked by the present approach. We
apply the method to study this subject in order to obtain the string constant,
which is in agreement with the experiments.


title:
Chern-Weil calculus extended to a class of infinite dimensional
  manifolds

abstract:
  We discuss possible extensions of the classical Chern-Weil formalism to an
infinite dimensional setup. This is based on joint work with Steven
  Rosenberg, joint work with Simon Scott and joint work with Jouko Mickelsson.


title:
The AMIGA sample of isolated galaxies. V. Quantification of the
  isolation

abstract:
  The AMIGA project aims to build a well defined and statistically significant
reference sample of isolated galaxies in order to estimate the environmental
effects on the formation and evolution of galaxies. The goal of this paper is
to provide a measure of the environment of the isolated galaxies in the AMIGA
sample, quantifying the influence of the candidate neighbours identified in our
previous work and their potential effects on the evolution of the primary
galaxies. Here we provide a quantification of the isolation degree of the
galaxies in this sample. Our starting sample is the Catalogue of Isolated
Galaxies (CIG). We used two parameters to estimate the influence exerted by the
neighbour galaxies on the CIG galaxy: the local number density of neighbour
galaxies and the tidal strength affecting the CIG galaxy. We show that both
parameters together provide a comprehensive picture of the environment. For
comparison, those parameters have also been derived for galaxies in denser
environments such as triplets, groups and clusters. The CIG galaxies show a
continuous spectrum of isolation, as quantified by the two parameters, from
very isolated to interacting. The fraction of CIG galaxies whose properties are
expected to be influenced by the environment is however low (159 out of 950
galaxies). The isolated parameters derived for the comparsion samples gave
higher values than for the CIG and we found clear differences for the average
values of the 4 samples considered, proving the sensitivity of these
parameters. The environment of the galaxies in the CIG has been characterised,
using two complementary parameters quantifying the isolation degree, the local
number density of the neighbour galaxies and the tidal forces affecting the
isolated galaxies. (Abridged)


title: Inhomogeneous High Frequency Expansion-Free Gravitational Waves

abstract:
  We describe a natural inhomogeneous generalization of high frequency plane
gravitational waves. The waves are high frequency waves of the Kundt type whose
null propagation direction in space-time has vanishing expansion, twist and
shear but is not covariantly constant. The introduction of a cosmological
constant is discussed in some detail and a comparison is made with high
frequency gravity waves having wave fronts homeomorphic to 2-spheres.


title: Heavy Flavor Production at HERA

abstract:
  Studies of charm and beauty production in ep collisions with a center-of-mass
energy of 318 GeV are reported from the two HERA collaborations, H1 and ZEUS.
The analyses make use of both the HERA-I data sample recorded between 1996 and
2000 and a sample from HERA-II, which started in 2003. The cross sections
measured by both H1 and ZEUS experiments are compared with next-to-leading
order QCD calculations. The measurement of the charm and beauty contributions
to the proton structure function is also presented. The comparison to
next-to-next-to-leading order (NNLO) calculations shows agreement within the
errors.


title: A phenomenological model of galaxy clusters

abstract:
  We present a simple model to describe the dark matter density, the gas
density, and the gas temperature profiles of galaxy clusters. Analytical
expressions for these quantities are given in terms of only five free
parameters with a clear physical meaning: the mass M of the dark matter halo
(or the characteristic temperature T_0), the characteristic scale radius a, the
cooling radius in units of a (0<alpha<1), the central temperature in units of
T_0 (0<t<1), and the asymptotic baryon fraction in units of the cosmic value
(f~1). It is shown that our model is able to reproduce the three-dimensional
density and temperature profiles inferred from X-ray observations of real
clusters within a 20 per cent accuracy over most of the radial range. Some
possible applications are briefly discussed.


title:
The physics and chemistry of circumstellar envelopes of S-stars on the
  AGB

abstract:
  The S-stars have been suggested to be a brief transitional phase as stars
evolve from oxygen-rich M-type stars into carbon stars, through the dredge up
of carbon from He-shell burning. As possible transition objects, S-stars might
help achieve a deeper understanding of the chemical evolution as a star ascends
the AGB, as well as shed more light on the mass-loss mechanism. We have
initiated a large survey of 40 S-stars to observe line emission in common
molecules such as CO, SiO, HCN, CS and SiS. Detailed radiative transfer
modelling of multi-transition CO radio line observations towards a sample of 40
S-stars shows that the mass-loss rate distribution of S-stars is consistent
with those found for M-type AGB stars and carbon stars. Initial results from
modelling of the circumstellar SiO emission are also presented.


title: Sparticle Mass Spectrum in Grand Unified Theories

abstract:
  We carry out a detailed analysis of sparticle mass spectrum in supersymmetric
grand unified theories. We consider the spectroscopy of the squarks and
sleptons in SU(5) and SO(10) grand unified theories, and show how the
underlying supersymmetry breaking parameters of these theories can be
determined from a measurement of different sparticle masses. This analysis is
done analytically by integrating the one-loop renormalization group equations
with appropriate boundary conditions implied by the underlying grand unified
gauge group. We also consider the impact of non-universal gaugino masses on the
sparticle spectrum, especially the neutralino and chargino masses which arise
in supersymmetric grand unified theories with non-minimal gauge kinetic
function. In particular, we study the interrelationships between the squark and
slepton masses which arise in grand unified theories at the one-loop level,
which can be used to distinguish between the different underlying gauge groups
and their breaking pattern to the Standard Model gauge group. We also comment
on the corrections that can affect these one-loop results.


title:
Study of multi-muon bundles in cosmic ray showers detected with the
  DELPHI detector at LEP

abstract:
  The DELPHI detector at LEP has been used to measure multi-muon bundles
originating from cosmic ray interactions with air. The cosmic events were
recorded in ``parasitic mode'' between individual e+e- interactions and the
total live time of this data taking is equivalent to 1.6x10^6 seconds. The
DELPHI apparatus is located about 100 metres underground and the 84 metres rock
overburden imposes a cut-off of about 52 GeV/c on muon momenta. The data from
the large volume Hadron Calorimeter allowed the muon multiplicity of 54201
events to be reconstructed. The resulting muon multiplicity distribution is
compared with the prediction of the Monte Carlo simulation based on
CORSIKA/QGSJET01. The model fails to describe the abundance of high
multiplicity events. The impact of QGSJET internal parameters on the results is
also studied.


title: X-ray observations of ultraluminous X-ray sources

abstract:
  Ultraluminous X-ray sources (ULXs) are amongst the most intriguing of X-ray
source classes. Their extreme luminosities - greater than 10^39 erg/s in the
0.3 - 10 keV band alone - suggest either the presence of black holes larger
than those regularly encountered in our own Galaxy (the Galactic centre
excepted), or sources apparently radiating well above the Eddington limit. We
review the insights afforded us by studies of their X-ray emission, focussing
on what this reveals about the underlying compact object. In particular, we
discuss recent deep observations of ULXs by the XMM-Newton observatory, and how
the unprecedented data quality provided by this mission is starting to
discriminate between the different physical models for these extraordinary
X-ray emitters.


title: On Poincare Polynomials of Hyperbolic Lie Algebras

abstract:
  We have general frameworks to obtain Poincare polynomials for Finite and also
Affine types of Kac-Moody Lie algebras. Very little is known however beyond
Affine ones, though we have a constructive theorem which can be applied both
for finite and infinite cases. One can conclusively said that theorem gives the
Poincare polynomial P(G) of a Kac-Moody Lie algebra G in the product form
P(G)=P(g) R where g is a precisely chosen sub-algebra of G and R is a rational
function. Not in the way which theorem says but, at least for 48 hyperbolic Lie
algebras considered in this work, we have shown that there is another way of
choosing a sub-algebra in such a way that R appears to be the inverse of a
finite polynomial. It is clear that a rational function or its inverse can not
be expressed in the form of a finite polynomial. Our method is based on
numerical calculations and results are given for each and every one of 48
Hyperbolic Lie algebras. In an illustrative example however, we will give how
above-mentioned theorem gives us rational functions in which case we find a
finite polynomial for which theorem fails to obtain.


title:
Hubble Space Telescope far-ultraviolet imaging of the jet in 3C273: a
  common emission component from optical to X-rays

abstract:
  We present far-ultraviolet (UV) observations at 150 nm of the jet of the
quasar 3C 273 obtained with the Advanced Camera for Survey's Solar Blind
Channel (ACS/SBC) on board the Hubble Space Telescope. While the jet morphology
is very similar to that in the optical and near-ultraviolet, the spectral
energy distributions (SEDs) of the jet's sub-regions show an upturn in nu f_nu
at 150 nm compared to 300 nm everywhere in the jet. Moreover, the 150 nm flux
is compatible with extrapolating the X-ray power-law down to the ultra-violet
region. This constitutes strong support for a common origin of the jet's far-UV
and X-ray emission. It implies that even a substantial fraction of the *visible
light* in the X-ray brightest parts of the jet arises from the same spectral
component as the X-rays, as had been suggested earlier based on Spitzer Space
Telescope observations. We argue that the identification of this UV/X-ray
component opens up the possibility to establish the synchrotron origin of the
X-ray emission by optical polarimetry.


title: Zgamma* production in e+e- interactions at sqrt{s} = 183 - 209 GeV

abstract:
  Measurements of Zgamma* production are presented using data collected by the
DELPHI detector at centre-of-mass energies ranging from 183 to 209 GeV,
corresponding to an integrated luminosity of about 667 pb^{-1}. The
measurements cover a wide range of the possible final state four-fermion
configurations: hadronic and leptonic (e+ e- q qbar, mu+ mu- q qbar, q qbar nu
nubar), fully leptonic (l+ l- l'+ l'-) and fully hadronic final states (q qbar
q qbar, with a low mass q qbar pair). Measurements of the Zgamma* cross-section
for the various final states have been compared with the Standard Model
expectations and found to be consistent within the errors. In addition, a total
cross-section measurement of the l+ l- l'+ l'- cross-section is reported, and
found to be in agreement with the prediction of the Standard Model.


title:
An anomaly detector with immediate feedback to hunt for planets of Earth
  mass and below by microlensing

abstract:
  (abridged) The discovery of OGLE 2005-BLG-390Lb, the first cool rocky/icy
exoplanet, impressively demonstrated the sensitivity of the microlensing
technique to extra-solar planets below 10 M_earth. A planet of 1 M_earth in the
same spot would have provided a detectable deviation with an amplitude of ~ 3 %
and a duration of ~ 12 h. An early detection of a deviation could trigger
higher-cadence sampling which would have allowed the discovery of an Earth-mass
planet in this case. Here, we describe the implementation of an automated
anomaly detector, embedded into the eSTAR system, that profits from immediate
feedback provided by the robotic telescopes that form the RoboNet-1.0 network.
It went into operation for the 2007 microlensing observing season. As part of
our discussion about an optimal strategy for planet detection, we shed some new
light on whether concentrating on highly-magnified events is promising and
planets in the 'resonant' angular separation equal to the angular Einstein
radius are revealed most easily. Given that sub-Neptune mass planets can be
considered being common around the host stars probed by microlensing
(preferentially M- and K-dwarfs), the higher number of events that can be
monitored with a network of 2m telescopes and the increased detection
efficiency for planets below 5 M_earth arising from an optimized strategy gives
a common effort of current microlensing campaigns a fair chance to detect an
Earth-mass planet (from the ground) ahead of the COROT or Kepler missions. The
detection limit of gravitational microlensing extends even below 0.1 M_earth,
but such planets are not very likely to be detected from current campaigns.
However, these will be within the reach of high-cadence monitoring with a
network of wide-field telescopes or a space-based telescope.


title: The hyperyoung HII region in G24.78+0.08 A1

abstract:
  Context. G24.78+0.08 A1 is a 20 Msun star surrounded by a hypercompact (HC)
HII region, driving a CO bipolar outflow, and located at the center of a
massive rotating toroid undergoing infall towards the HC region. Recent water
maser observations suggest that the HC region is expanding and accretion onto
the star is halted. Aims. This study aims to confirm the expansion scenario
proposed for the HC region on the basis of recent H2O maser observations.
Methods. We carried out continuum VLA observations at 1.3cm and 7mm with the A
array plus Pie Town configuration to map the HC region towards G24 A1. Results.
The emission of the HC region has been resolved and shows a ring shape
structure. The profiles of the emission obtained by taking slices at different
angles passing through the barycenter of the HC region confirm the shell
structure of the emission. The ratio between the inner and the outer radius of
the shell, Ri/Ro, derived fitting the normalized brightness temperature profile
passing through the peak of the 7mm emission, is 0.9, which indicates that the
shell is thin. The deconvolved outer radius estimated from the fit is 590 AU.
These results imply that the HC region in G24 A1 cannot be described in terms
of a classical, homogeneous HII region but is instead an ionized shell. This
gives support to the model of an expanding wind-driven, ionized shell suggested
by the kinematics and distribution of the H2O masers associated with the HC
region. According to this model, the HC region is expanding on very short times
scales, 21-66 yr.


title:
Effect of Hetrovalent substitution at Mn site on the Magnetic and
  Transport Properties of La$_{0.67}$Sr$_{0.33}$MnO$_3$

abstract:
  Magnetic and transport properties of Ti substituted
La$_{0.67}$Sr$_{0.33}$MnO$_3$ are drastically affected with a change in
preparation conditions. Low temperature infra-red absorption measurements
reveal that this is perhaps due to inhomogeniety in substitution of Ti$^{4+}$
on Mn sites. It is found that, in the high temperature annealed samples, the
substitution of Ti supresses the double exchange interaction due to the
formation of Mn$^{3+}$-O-Ti$^{4+}$ chains. While in the low temperature
annealed case substitution of Ti causes formation of isolated ferromagnetic
clusters linked to each other by a variable range hopping polaron.


title:
Comparative study of various algorithms for the merging of parton
  showers and matrix elements in hadronic collisions

abstract:
  We compare different procedures for combining fixed-order tree-level
matrix-element generators with parton showers. We use the case of W-production
at the Tevatron and the LHC to compare different implementations of the
so-called CKKW and MLM schemes using different matrix-element generators and
different parton cascades. We find that although similar results are obtained
in all cases, there are important differences.


title: Gray Curvature Identities for Almost Contact Metric Manifolds

abstract:
  The aim of this research is the study of Gray curvature identities,
introduced by Alfred Gray in \cite{kn:Gra76} for the class of almost hermitian
manifolds. As known till now, there is no equivalent for the class of almost
contact manifolds. For this purpose we use the Boohby-Wang fibration and the
warped manifolds construction in order to establish which identities could be
satisfied by an almost contact manifold.


title:
The contribution of Oxygen-Neon white dwarfs to the MACHO content of the
  Galactic Halo

abstract:
  The interpretation of microlensing results towards the Large
  Magellanic Cloud (LMC) still remains controversial. White dwarfs have been
proposed to explain these results and, hence, to contribute significantly to
the mass budget of our Galaxy. However, several constraints on the role played
by regular carbon-oxygen white dwarfs exist. Massivewhite dwarfs are thought to
be made of a mixture of oxygen and neon. Correspondingly, their cooling rate is
larger than those of typical carbon-oxygen white dwarfs and they fade to
invisibility in short timescales. Consequently, they constitute a good
candidate for explaining the microlensing results. Here, we examine in detail
this hypothesis by using the most recent and up-to-date cooling tracks for
massive white dwarfs and a Monte Carlo simulator which takes into account the
most relevant Galactic inputs. We find that oxygen-neon white dwarfs cannot
account for a substantial fraction of the microlensing depth towards the LMC,
independently of the adopted initial mass function, although some microlensing
events could be due to oxygen--neon white dwarfs. The white dwarf population
contributes at most a 5% to the mass of the Galactic halo.


title: The Blackholic energy and the canonical Gamma-Ray Burst

abstract:
  We outline the main results of our GRB model, based on the three
interpretation paradigms we proposed in July 2001, comparing and contrasting
them with the ones in the current literature. Thanks to the observations by
Swift and by VLT, this analysis points to a "canonical GRB" originating from
markedly different astrophysical scenarios. The communality is that they are
all emitted in the formation of a black hole with small or null angular
momentum. The following sequence appears to be canonical: the vacuum
polarization process creating an optically thick self accelerating
electron-positron plasma; the engulfment of baryonic mass during the plasma
expansion; the adiabatic expansion of the optically thick "fireshell" up to the
transparency; the interaction of the remaining accelerated baryons with the
interstellar medium (ISM). This leads to the canonical GRB composed of a proper
GRB (P-GRB), emitted at the moment of transparency, followed by an extended
afterglow. The parameters are the plasma total energy, the fireshell baryon
loading and the ISM filamentary distribution around the source. In the limit of
no baryon loading the total energy is radiated in the P-GRB. In this limit, the
canonical GRBs explain as well the short GRBs.


title:
VLT/NACO observations of the High-Magnetic field radio pulsar PSR
  J1119-6127

abstract:
  Recent radio observations have unveiled the existence of a number of radio
pulsars with spin-down derived magnetic fields in the magnetar range. However,
their observational properties appears to be more similar to classical radio
pulsars than to magnetars. To shed light on this puzzle we first have to
determine whether the spin-down derived magnetic field values for these radio
pulsars are indeed representative of the actual neutron star magnetic field or
if they are polluted, e.g. by the effects of a torque from a fallback disk. To
investigate this possibility, we have performed deep IR observations of one of
these high magnetic field radio pulsars (PSR J1119-6127) with the ESO VLT to
search for IR emission which can be associated with a disk. No IR emission is
detected from the pulsar position down to J=24, H=23, Ks=22. By comparing our
flux upper limits with the predictions of fallback disk models, we have found
that we can only exclude the presence of a disk with accretion rate dot M
>3x10^16 g/s. This lower limit cannot rule out the presence of a substantial
disk torque on the pulsar, which would then lead to overestimate the value of
the magnetic field inferred from P and dot P.


title:
The narrow-line region of narrow-line and broad-line type 1 AGN I. A
  zone of avoidance in density

abstract:
  The properties of narrow-line Seyfert 1 (NLS1) galaxies, the links and
correlations between them, and the physics behind them, are still not well
understood. Apart from accretion rates and black hole masses, density and
outflows were speculated to be among the main drivers of the NLS1 phenomenon.
Here, we utilize the diagnostic power of the [SII]6716,6731 intensity ratio to
measure the density of the NLR systematically and homogeneously for a large
sample of NLS1 galaxies, and we perform a comparison with a sample of
broad-line type 1 AGN. We report the discovery of a zone of avoidance in
density in the sense that AGN with broad lines (FWHM_Hbeta > 2000 km/s) avoid
low densities, while NLS1 galaxies show a wider distribution in the NLR
density, including a significant number of objects with low densities. A
correlation analysis further shows that the Eddington ratio L/L_Edd
anti-correlates with density. We investigate a number of different models for
the zone of avoidance in density. Supersolar metallicities and temperature
effects, a strong starburst contribution in NLS1 galaxies, different NLR
extents and selective obscuration are considered unlikely. Possible differences
in the fraction of matter-bounded clouds and differences in the interstellar
media of the host galaxies of NLS1 galaxies and broad-line Seyfert 1 (BLS1)
galaxies can only be tested further with future observations. We tentatively
favor the effects of winds/outflows, stronger in NLS1 galaxies than in BLS1
galaxies, to explain the observations.


title: A new lower bound on the independence number of a graph

abstract:
  For a given connected graph G on n vertices and m edges, we prove that its
independence number is at least (2m+n+2-sqrt(sqr(2m+n+2)-16sqr(n)))/8.


title:
First performance studies of a prototype for the CASTOR forward
  calorimeter at the CMS experiment

abstract:
  We present results on the performance of the first prototype of the CASTOR
quartz-tungsten sampling calorimeter, to be installed in the very forward
region of the CMS experiment at the LHC. This study includes GEANT Monte Carlo
simulations of the Cherenkov light transmission efficiency of different types
of air-core light guides, as well as analysis of the calorimeter linearity and
resolution as a function of energy and impact-point, obtained with 20-200 GeV
electron beams from CERN/SPS tests in 2003. Several configurations of the
calorimeter have been tested and compared, including different combinations of
(i) structures for the active material of the calorimeter (quartz plates and
fibres), (ii) various light-guide reflecting materials (glass and foil
reflectors) and (iii) photodetector devices (photomultipliers and avalanche
photodiodes).


title: A Groshev Theorem for Small Linear Forms

abstract:
  In this paper the absolute value or distance from the origin analogue of the
classical Khintchine-Groshev theorem is established for a single linear form
with a `slowly decreasing' error function.


title:
Using the $e^\pm \mu^\mp + E^{miss}_T$ and $l^+l^- + E^{miss}_T$
  Signatures in the Search for Supersymmetry and Constraining the MSSM model at
  LHC

abstract:
  We study the $e^{\pm}\mu^{\mp} + E^{miss}_T$ and $l^+l^- + E^{miss}_T$
signatures $(l = e, \mu)$ for different values of $\tan\beta$ in the mSUGRA
model. With $\tan\beta$ rising, we observe a characteristic change in the shape
of dilepton mass spectra in $l^+l^- + E^{miss}_T $ versus $e^{\pm}\mu^{\mp}$
final states reflecting the decrease of $\tilde{\chi}^0_2 \to l^+l^-
\tilde{\chi^0_1}$ branching ratio. We also study the non mSUGRA modifications
of the CMS test point LM1 with arbitrary relations among gaugino and higgsino
masses. For such modifications of the mSUGRA test point LM1 the number of
lepton events depends rather strongly on the relations among gaugino and
higgsino masses and in some modifications of the test point LM1 the signatures
with leptons and $E_{T}^{miss}$ do not lead to the SUSY discovery and the
single SUSY discovery signature remains the signature with $n \geq 2 jets +
E^{miss}_T + no leptons$.


title: Prescribing the behaviour of geodesics in negative curvature

abstract:
  Given a family of (almost) disjoint strictly convex subsets of a complete
negatively curved Riemannian manifold M, such as balls, horoballs, tubular
neighborhoods of totally geodesic submanifolds, etc, the aim of this paper is
to construct geodesic rays or lines in M which have exactly once an exactly
prescribed (big enough) penetration in one of them, and otherwise avoid (or do
not enter too much in) them. Several applications are given, including a
definite improvement of the unclouding problem of [PP1], the prescription of
heights of geodesic lines in a finite volume such M, or of spiraling times
around a closed geodesic in a closed such M. We also prove that the Hall ray
phenomenon described by Hall in special arithmetic situations and by
Schmidt-Sheingorn for hyperbolic surfaces is in fact only a negative curvature
property.


title: Planar maps whose second iterate has a unique fixed point

abstract:
  Let a>0, F: R^2 -> R^2 be a differentiable (not necessarily C^1) map and
Spec(F) be the set of (complex) eigenvalues of the derivative F'(p) when p
varies in R^2.
  (a) If Spec(F) is disjoint of the interval [1,1+a[, then Fix(F) has at most
one element, where Fix(F) denotes the set of fixed points of F.
  (b) If Spec(F) is disjoint of the real line R, then Fix(F^2) has at most one
element.
  (c) If F is a C^1 map and, for all p belonging to R^2, the derivative F'(p)
is neither a homothety nor has simple real eigenvalues, then Fix(F^2) has at
most one element, provided that Spec(F) is disjoint of either
  (c1) the union of the number 0 with the intervals ]-\infty, -1] and
[1,\infty[, or (c2) the interval [-1-a, 1+a]. Conditions under which Fix(F^n),
with n>1, is at most unitary are considered.


title: Internal labelling operators and contractions of Lie algebras

abstract:
  We analyze under which conditions the missing label problem associated to a
reduction chain $\frak{s}^{\prime}\subset \frak{s}$ of (simple) Lie algebras
can be completely solved by means of an In\"on\"u-Wigner contraction $\frak{g}$
naturally related to the embedding. This provides a new interpretation of the
missing label operators in terms of the Casimir operators of the contracted
algebra, and shows that the available labeling operators are not completely
equivalent. Further, the procedure is used to obtain upper bounds for the
number of invariants of affine Lie algebras arising as contractions of
semisimple algebras.


title:
Diagrammatic content of the DMFT for the Holstein polaron problem in
  finite dimensions

abstract:
  In the context of the Holstein polaron problem it is shown that the dynamical
mean field theory (DMFT) corresponds to the summation of a special class of
local diagrams in the skeleton expansion of the self-energy. In the real space
representation, these local diagrams are characterized by the absence of vertex
corrections involving phonons at different lattice sites. Such corrections
vanish in the limit of infinite dimensions, for which the DMFT provides the
exact solution of the Holstein polaron problem. However, for finite dimensional
systems the accuracy of the DMFT is limited. In particular, it cannot describe
correctly the adiabatic spreading of the polaron over multiple lattice sites.
Arguments are given that the DMFT limitations on vertex corrections found for
the Holstein polaron problem persist for finite electron densities and
arbitrary phonon dispersion.


title:
Hindered Coulomb explosion of embedded Na clusters -- stopping, shape
  dynamics and energy transport

abstract:
  We investigate the dynamical evolution of a Na$_8$ cluster embedded in Ar
matrices of various sizes from N=30 to 1048. The system is excited by an
intense short laser pulse leading to high ionization stages. We analyze the
subsequent highly non-linear motion of cluster and Ar environment in terms of
trajectories, shapes, and energy flow. The most prominent effects are:
temporary stabilization of high charge states for several ps, sudden stopping
of the Coulomb explosion of the embedded Na$_8$ clusters associated with an
extremely fast energy transfer to the Ar matrix, fast distribution of energy
throughout the Ar layers by a sound wave. Other ionic-atomic transfer and
relaxation processes proceed at slower scale of few ps. The electron cloud is
almost thermally decoupled from ions and thermalizes far beyond the ps scale.


title:
Vortex States Induced by Proximity Effect in Hybrid
  Ferromagnet-Superconductor Systems

abstract:
  We consider superconductivity nucleation in multiply connected mesoscopic
samples such as thin-walled cylinders or rings placed in electrical contact
with a ferromagnet. The superconducting critical temperature and order
parameter structure are studied on the basis of linearized Usadel equations. We
suggest a mechanism of switching between the superconducting states with
different vorticities caused by the exchange field and associated with the
oscillatory behavior of the Cooper pair wave function in a ferromagnet.


title: Decisive Markov Chains

abstract:
  We consider qualitative and quantitative verification problems for
infinite-state Markov chains. We call a Markov chain decisive w.r.t. a given
set of target states F if it almost certainly eventually reaches either F or a
state from which F can no longer be reached. While all finite Markov chains are
trivially decisive (for every set F), this also holds for many classes of
infinite Markov chains. Infinite Markov chains which contain a finite attractor
are decisive w.r.t. every set F. In particular, this holds for probabilistic
lossy channel systems (PLCS). Furthermore, all globally coarse Markov chains
are decisive. This class includes probabilistic vector addition systems (PVASS)
and probabilistic noisy Turing machines (PNTM). We consider both safety and
liveness problems for decisive Markov chains, i.e., the probabilities that a
given set of states F is eventually reached or reached infinitely often,
respectively. 1. We express the qualitative problems in abstract terms for
decisive Markov chains, and show an almost complete picture of its decidability
for PLCS, PVASS and PNTM. 2. We also show that the path enumeration algorithm
of Iyer and Narasimha terminates for decisive Markov chains and can thus be
used to solve the approximate quantitative safety problem. A modified variant
of this algorithm solves the approximate quantitative liveness problem. 3.
Finally, we show that the exact probability of (repeatedly) reaching F cannot
be effectively expressed (in a uniform way) in Tarski-algebra for either PLCS,
PVASS or (P)NTM.


title: Nuclear Cosmic Rays propagation in the Atmosphere

abstract:
  The transport of the nuclear cosmic ray flux in the atmosphere is studied and
the atmospheric corrections to be applied to the measurements are calculated.
The contribution of the calculated corrections to the accuracy of the
experimental results are discussed and evaluated over the kinetic energy range
10-10$^{3}$ GeV/n. The Boron (B) and Carbon (C) elements system is used as a
test case. It is shown that the required corrections become largely dominant at
the highest energies investigated. The results are discussed.


title: Electroproduction of longitudinally polarized vector mesons

abstract:
  It is reported on an analysis of electroproduction of light vector mesons at
small Bjorken-x within the handbag approach. The partonic subprocesses, meson
electroproduction off quarks or gluons, are calculated within the modified
perturbative approach in which quark transverse momenta are retained. The soft
hadronic matrix elements, generalized parton distributions, are constructed
from the CTEQ6 parton distribution functions by means of double distributions.
The cross sections for longitudinal polarized virtual photons evaluated from
this approach, are in very good agreement with experiment in a wide range of
kinematics. Talk presented at the DIS2007 conference, Munich (2007)


title: Betti numbers for fat point ideals in the plane: a geometric approach

abstract:
  We consider the open problem of determining the graded Betti numbers for fat
point subschemes supported at general points of the projective plane. We relate
this problem to the open geometric problem of determining the splitting type of
the pullback of the cotangent bundle on the plane to the normalization of
certain rational plane curves. We give a conjecture for the graded Betti
numbers which would determine them in all degrees but one for every fat point
subscheme supported at general points of the plane. We also prove our Betti
number conjecture in a broad range of cases. An appendix discusses many more
cases in which our conjecture has been verified computationally and provides a
new and more efficient computational approach for computing graded Betti
numbers in certain degrees. It also demonstrates how to derive explicit
conjectural values for the Betti numbers and how to compute splitting types.


title:
The aligned nuclear targets for investigation of time reversal
  invariance violation: thermal heating and optimization of target dimension

abstract:
  The thermal heating of aligned nuclear targets of HIO_3, LiIO_3 ans Sb target
materials under neutron irradiation at JSNS is considered. It is shown that
presently the targets of large volumes (several tens of cm^3) can be used in
experiment. The optimal target dimensions are recommended for investigation
with resonance neutrons. The use of proposed aligned targets at the new neutron
spallation source JSNS (Japan) will make p[ossible to discover TRIV or decrease
the present limit on the intensity of parity conserving time violating
interaction by two-three order of magnitude.


title: Extreme Value Theory and the Solar Cycle

abstract:
  We investigate the statistical properties of the extreme events of the solar
cycle as measured by the sunspot number. The recent advances in the methodology
of the theory of extreme values is applied to the maximal extremes of the time
series of sunspots. We focus on the extreme events that exceed a carefully
chosen threshold and a generalized Pareto distribution is fitted to the tail of
the empirical cumulative distribution. A maximum likelihood method is used to
estimate the parameters of the generalized Pareto distribution and confidence
levels are also given to the parameters. Due to the lack of an automatic
procedure for selecting the threshold, we analyze the sensitivity of the fitted
generalized Pareto distribution to the exact value of the threshold. According
to the available data, that only spans the previous ~250 years, the cumulative
distribution of the time series is bounded, yielding an upper limit of 324 for
the sunspot number. We also estimate that the return value for each solar cycle
is ~188, while the return value for a century increases to ~228. Finally, the
results also indicate that the most probable return time for a large event like
the maximum at solar cycle 19 happens once every ~700 years and that the
probability of finding such a large event with a frequency smaller than ~50
years is very small. In spite of the essentially extrapolative character of
these results, their statistical significance is very large.


title: Self-assembled Pt nanowires on Ge(001): Relaxation effects

abstract:
  Absorption of Pt on the Ge(001) surface results in stable self-organized Pt
nanowires, extending over some hundred nanometers. Based on band structure
calculations within density functional theory and the generalized gradient
approximation, the structural relaxation of the Ge--Pt surface is investigated.
The surface reconstruction pattern obtained agrees well with findings from
scanning tunneling microscopy. In particular, strong Pt--Pt dimerization is
characteristical for the nanowires. The surface electronic structure is
significantly perturbed due to Ge--Pt interaction, which induces remarkable
shifts of Ge states towards the Fermi energy. As a consequence, the topmost Ge
layers are subject to a metal-insulator transition.


title: Inhomogeneous and self-organised temperature in Schelling-Ising model

abstract:
  The Schelling model of 1971 is a complicated version of a square-lattice
Ising model at zero temperature, to explain urban segregation, based on the
neighbour preferences of the residents, without external reasons. Various
versions between Ising and Schelling models give about the same results.
Inhomogeneous "temperatures" T do not change the results much, while a feedback
between segregation and T leads to a self-organisation of an average T.


title: Using the Zeldovich dynamics to test expansion schemes

abstract:
  We apply various expansion schemes that may be used to study gravitational
clustering to the simple case of the Zeldovich dynamics. Using the well-known
exact solution of the Zeldovich dynamics we can compare the predictions of
these various perturbative methods with the exact nonlinear result and study
their convergence properties. We find that most systematic expansions fail to
recover the decay of the response function in the highly nonlinear regime.
``Linear methods'' lead to increasingly fast growth in the nonlinear regime for
higher orders, except for Pade approximants that give a bounded response at any
order. ``Nonlinear methods'' manage to obtain some damping at one-loop order
but they fail at higher orders. Although it recovers the exact Gaussian
damping, a resummation in the high-k limit is not justified very well as the
generation of nonlinear power does not originate from a finite range of
wavenumbers (hence there is no simple separation of scales). No method is able
to recover the relaxation of the matter power spectrum on highly nonlinear
scales. It is possible to impose a Gaussian cutoff in a somewhat ad-hoc fashion
to reproduce the behavior of the exact two-point functions for two different
times. However, this cutoff is not directly related to the clustering of matter
and disappears in exact equal-time statistics such as the matter power
spectrum. On a quantitative level, the usual perturbation theory, and the
nonlinear scheme to which one adds an ansatz for the response function with
such a Gaussian cutoff, are the two most efficient methods. These results
should hold for the gravitational dynamics as well (this has been checked at
one-loop order), since the structure of the equations of motion is identical
for both dynamics.


title:
Baryogenesis from the amplification of vacuum fluctuations during
  inflation

abstract:
  We propose that the baryon asymmetry of the Universe may originate from the
amplification of quantum fluctuations of a light complex scalar field during
inflation. CP-violation is sourced by complex mass terms, which are smaller
than the Hubble rate, as well as non-standard kinetic terms. We find that, when
assuming 60 e-folds of inflation, an asymmetry in accordance with observation
can result for models where the energy scale of inflation is of the order of
10^16 GeV. Lower scales may be achieved when assuming substantially larger
amounts of e-folds.


title: The Kashiwara-Vergne conjecture

abstract:
  This is a Bourbaki's seminar text. We introduce the combinatorial
Kashiwara-Vergne conjecture on the Baker-Campbell-Hausdorff serie. After
recalling previous results and consequences, we explain the
Alekseev-Meinrenken's proof [math.QA/0506499]


title: Is the Interpretation of Delayed-Choice Experiments Misleading?

abstract:
  The interpretation of an experimental realization of Wheeler's delayed-choice
gedanken experiment is discussed and called into question.


title: Propagation of UHE protons through a magnetized large scale structure

abstract:
  The propagation of UHECRs is affected by the intergalactic magnetic fields
that were produced during the course of the large scale structure formation of
the universe. We adopt a novel model where the large scale extragalactic
magnetic fields (EGMF) are estimated from local dynamic properties of the gas
flows in hydrodynamic simulations of a concordance LambdaCDM universe. With the
model magnetic fields, we calculate the deflection angle, time delay and energy
spectrum of protons with E > 10^{19} eV that are injected at cosmological
sources and then travel through the large scale structure of the universe,
losing the energy due to interactions with the cosmic background radiation.
Implications of this study on the origin of UHECRs are discussed.