title: Phase Transition Properties of 3D Potts Models

abstract:
  Using multicanonical Metropolis simulations we estimate phase transition
properties of 3D Potts models for q=4 to 10: The transition temperatures,
latent heats, entropy gaps, normalized entropies at the disordered and ordered
endpoints, interfacial tensions, and spinodal endpoints.


title: Proper motion of reference radio sources

abstract:
  The motion of relativistic jets from the active extragalactic nuclei can
reach several hundred microseconds per year and mimic proper motion of the
distant radio sources observed by VLBI. Such motion of individual quasar is not
correlated and its magnitude exceeds the small systematic effects induced by
the rotation of the Solar system around the centre of the Galaxy. In this paper
we search for the cause of the systematic effect and discuss the results.


title: Optimal Entanglement Formulas for Entanglement-Assisted Quantum Coding

abstract:
  We provide several formulas that determine the optimal number of entangled
bits (ebits) that a general entanglement-assisted quantum code requires. Our
first theorem gives a formula that applies to an arbitrary
entanglement-assisted block code. Corollaries of this theorem give formulas
that apply to a code imported from two classical binary block codes, to a code
imported from a classical quaternary block code, and to a continuous-variable
entanglement-assisted quantum block code. Finally, we conjecture two formulas
that apply to entanglement-assisted quantum convolutional codes.


title: Black-body photon clustering by semi-classical means

abstract:
  If stimulated emission could be turned off then only uncorrelated photons
would be emitted from black bodies and the photon counting statistics would be
Poissonian. Through the process of stimulated emission, some fraction of the
photons emitted from a black body are correlated and thus emitted in clusters.
This photon clustering can be calculated by semi-classical means. The
corresponding results are in agreement with quantum theory.


title:
Localized Solitons of a (2+1)-dimensional Nonlocal Nonlinear
  Schr\"odinger Equation

abstract:
  A new integrable (2+1)-dimensional nonlocal nonlinear Schr\"odinger equation
is proposed. The $N$-soliton solution is given by Gram type determinant. It is
found that the localized N-soliton solution has interesting interaction
behavior which shows change of amplitude of localized pulses after collisions.


title: Relative support varieties

abstract:
  We define relative support varieties with respect to some fixed module over a
finite dimensional algebra. These varieties share many of the standard
properties of classical support varieties. Moreover, when introducing finite
generation conditions on cohomology, we show that relative support varieties
contain homological information on the modules involved. As an application, we
provide a new criterion for a selfinjective algebra to be of wild
representation type.


title: Lotsize optimization leading to a $p$-median problem with cardinalities

abstract:
  We consider the problem of approximating the branch and size dependent demand
of a fashion discounter with many branches by a distributing process being
based on the branch delivery restricted to integral multiples of lots from a
small set of available lot-types. We propose a formalized model which arises
from a practical cooperation with an industry partner. Besides an integer
linear programming formulation and a primal heuristic for this problem we also
consider a more abstract version which we relate to several other classical
optimization problems like the p-median problem, the facility location problem
or the matching problem.


title: Discovering More Accurate Frequent Web Usage Patterns

abstract:
  Web usage mining is a type of web mining, which exploits data mining
techniques to discover valuable information from navigation behavior of World
Wide Web users. As in classical data mining, data preparation and pattern
discovery are the main issues in web usage mining. The first phase of web usage
mining is the data processing phase, which includes the session reconstruction
operation from server logs. Session reconstruction success directly affects the
quality of the frequent patterns discovered in the next phase. In reactive web
usage mining techniques, the source data is web server logs and the topology of
the web pages served by the web server domain. Other kinds of information
collected during the interactive browsing of web site by user, such as cookies
or web logs containing similar information, are not used. The next phase of web
usage mining is discovering frequent user navigation patterns. In this phase,
pattern discovery methods are applied on the reconstructed sessions obtained in
the first phase in order to discover frequent user patterns. In this paper, we
propose a frequent web usage pattern discovery method that can be applied after
session reconstruction phase. In order to compare accuracy performance of
session reconstruction phase and pattern discovery phase, we have used an agent
simulator, which models behavior of web users and generates web user navigation
as well as the log data kept by the web server.


title:
Asymptotically Friedmann self-similar scalar field solutions with
  potential

abstract:
  We investigate self-similar solutions which are asymptotic to the Friedmann
universe at spatial infinity and contain a scalar field with potential. The
potential is required to be exponential by self-similarity. It is found that
there are two distinct one-parameter families of asymptotic solutions,one is
asymptotic to the proper Friedmann universe, while the other is asymptotic to
the quasi-Friedmann universe, i.e., the Friedmann universe with anomalous solid
angle. The asymptotically proper Friedmann solution is possible only if the
universe is accelerated or the potential is negative. If the potential is
positive, the density perturbation in the asymptotically proper Friedmann
solution rapidly falls off at spatial infinity, while the mass perturbation is
compensated. In the asymptotically quasi-Friedmann solution, the density
perturbation falls off only in proportion to the inverse square of the areal
radius and the relative mass perturbation approaches a nonzero constant at
spatial infinity. The present result shows that a necessary condition holds in
order that a self-gravitating body grows self-similarly due to the constant
accretion of quintessence in an accelerating universe.


title:
The Long-Term Variability of the X-Ray Sources in NGC 6946 and NGC
  4485/4490

abstract:
  We analyze data from five Chandra observations of the spiral galaxy NGC 6946
and from three Chandra observations of the irregular/spiral interacting galaxy
pair NGC 4485/4490, with an emphasis on investigating the long-term variability
exhibited by the source populations. We detect 90 point sources coincident with
NGC 6946 down to luminosities of a few times 10^36 erg/s, and 38 sources
coincident with NGC 4485/90 down to a luminosity of ~1x10^37 erg/s. Twenty-five
(15) sources in NGC 6946 (NGC 4485/90) exhibit long-term (i.e., weeks to years)
variability in luminosity; 11 (4) are transient candidates. The single
ultraluminous X-ray source (ULX) in NGC 6946 and all but one of the eight ULXs
in NGC 4485/90 exhibit long-term flux variability. Two of the ULXs in NGC
4485/90 have not been identified before as ultraluminous sources. The
widespread variability in both systems is indicative of the populations being
dominated by X-ray binaries, and this is supported by the X-ray colors of the
sources. The distribution of colors among the sources indicates a large
fraction of high-mass X-ray binaries in both systems. The shapes of the X-ray
luminosity functions of the galaxies do not change significantly between
observations and can be described by power laws with cumulative slopes ~0.6-0.7
(NGC 6946) and ~0.4 (NGC 4485/90).


title:
The Top-Dog Index: A New Measurement for the Demand Consistency of the
  Size Distribution in Pre-Pack Orders for a Fashion Discounter with Many Small
  Branches

abstract:
  We propose the new Top-Dog-Index, a measure for the branch-dependent historic
deviation of the supply data of apparel sizes from the sales data of a fashion
discounter. A common approach is to estimate demand for sizes directly from the
sales data. This approach may yield information for the demand for sizes if
aggregated over all branches and products. However, as we will show in a
real-world business case, this direct approach is in general not capable to
provide information about each branch's individual demand for sizes: the supply
per branch is so small that either the number of sales is statistically too
small for a good estimate (early measurement) or there will be too much
unsatisfied demand neglected in the sales data (late measurement). Moreover, in
our real-world data we could not verify any of the demand distribution
assumptions suggested in the literature. Our approach cannot estimate the
demand for sizes directly. It can, however, individually measure for each
branch the scarcest and the amplest sizes, aggregated over all products. This
measurement can iteratively be used to adapt the size distributions in the
pre-pack orders for the future. A real-world blind study shows the potential of
this distribution free heuristic optimization approach: The gross yield
measured in percent of gross value was almost one percentage point higher in
the test-group branches than in the control-group branches.


title:
High-temperature spin relaxation process in Dy$_2$Ti$_2$O$_7$ probed by
  $^{47}$Ti-NQR

abstract:
  We have performed nuclear quadrupole resonance (NQR) experiments on $^{47}$Ti
nuclei in Dy$_2$Ti$_2$O$_7$ in the temperature range 70 -- 300 K in order to
investigate the dynamics of $4f$ electrons with strong Ising anisotropy. A
significant change of the NQR frequency with temperature was attributed to the
variation of the quadrupole moment of Dy $4f$ electrons. A quantitative account
was given by the mean field analysis of the quadrupole-quadrupole (Q-Q)
interaction in the presence of the crystalline-electric-field splitting. The
magnitude and the temperature dependence of the nuclear spin-lattice relaxation
rate was analyzed, including both the spin-spin and the Q-Q interactions. The
results indicate that these two types of interaction contribute almost equally
to the fluctuation of Dy magnetic moments.


title:
Demand forecasting for companies with many branches, low sales numbers
  per product, and non-recurring orderings

abstract:
  We propose the new Top-Dog-Index to quantify the historic deviation of the
supply data of many small branches for a commodity group from sales data. On
the one hand, the common parametric assumptions on the customer demand
distribution in the literature could not at all be supported in our real-world
data set. On the other hand, a reasonably-looking non-parametric approach to
estimate the demand distribution for the different branches directly from the
sales distribution could only provide us with statistically weak and unreliable
estimates for the future demand. Based on real-world sales data from our
industry partner we provide evidence that our Top-Dog-Index is statistically
robust. Using the Top-Dog-Index, we propose a heuristics to improve the
branch-dependent proportion between supply and demand. Our approach cannot
estimate the branch-dependent demand directly. It can, however, classify the
branches into a given number of clusters according to an historic oversupply or
undersupply. This classification of branches can iteratively be used to adapt
the branch distribution of supply and demand in the future.


title:
A lower bound for the principal eigenvalue of the Stokes operator in a
  random domain

abstract:
  This article is dedicated to localization of the principal eigenvalue (PE) of
the Stokes operator acting on solenoidal vector fields that vanish outside a
large random domain modeling the pore space in a cubic block of porous material
with disordered micro-structure. Its main result is an asymptotically
deterministic lower bound for the PE of the sum of a low compressibility
approximation to the Stokes operator and a small scaled random potential term,
which is applied to produce a similar bound for the Stokes PE. The arguments
are based on the method proposed by F. Merkl and M. V. W\"{u}trich for
localization of the PE of the Schr\"{o}dinger operator in a similar setting.
Some additional work is needed to circumvent the complications arising from the
restriction to divergence-free vector fields of the class of test functions in
the variational characterization of the Stokes PE.


title: The C1 generic diffeomorphism has trivial centralizer

abstract:
  Answering a question of Smale, we prove that the space of C1 diffeomorphisms
of a compact manifold contains a residual subset of diffeomorphisms whose
centralizers are trivial.


title:
Method of wave equations exact solutions in studies of neutrinos and
  electrons interaction in dense matter

abstract:
  We present quite a powerful method in investigations of different phenomena
that can appear when neutrinos and electrons propagate in background matter.
This method implies use of exact solutions of modified Dirac equations that
contain the correspondent effective potentials accounting for the matter
influence on particles. For several particular cases the exact solutions of
modified Dirac and Dirac-Pauli equations for a neutrino and an electron in the
background environment of different composition are obtained (the case of
magnetized matter is also considered). Neutrino reflection, trapping, neutrino
pair creation and annihilation in matter and neutrino energy quantization in a
rotating medium are discussed. The neutrino Green functions in matter are also
derived. The two recently proposed mechanisms of electromagnetic radiation by a
neutrino and an electron in matter (the spin light of neutrino and electron,
$SL\nu$ and $SLe$) are considered. A possibility to introduce an effective
"matter-induced Lorentz force" acting on a neutrino and an electron is
discussed. A new mechanism of electromagnetic radiation that can be emitted by
an electron moving in the neutrino background with non-zero gradient of density
is predicted.


title: Smooth Yamabe invariant and surgery

abstract:
  We prove a surgery formula for the smooth Yamabe invariant $\sigma(M)$ of a
compact manifold $M$. Assume that $N$ is obtained from $M$ by surgery of
codimension at least 3. We prove the existence of a positive number
$\Lambda_n$, depending only on the dimension $n$ of $M$, such that $$ \sigma(N)
\geq \min{\sigma(M),\Lambda_n}. $$


title: Sur la g\'eom\'etrie systolique des vari\'et\'es de Bieberbach

abstract:
  The systole of a compact non simply connected Riemannian manifold is the
smallest length of a non-contractible closed curve ; the systolic ratio is the
quotient $(\mathrm{systole})^n/\mathrm{volume}$. Its supremum on the set of all
the riemannian metrics, is known to be finite for a large class of manifolds,
including the $K(\pi,1)$. We study the optimal systolic ratio of compact,
3-dimensional non orientable Bieberbach manifolds, and prove that it cannot be
realized by a flat metric.


title: The ion pairs and superconducting bosons

abstract:
  First, it is shown that the creation of the spinless ion pairs in the
lattice, which are hold by the binding with neighbor ion pairs together
regarded as covalent. These ion pairs are created by the repulsive potential
interaction of two ions which is bound as linear oscillator. The repulsive
S-wave scattering between ion pairs and electrons is transformed to the
attractive effective interaction between electrons which leads to a creation of
electron pairs by a binding energy depending on the condensate fraction of ion
pairs $\frac{N_0}{N}$. In this respect, the absence of ion pairs in the
condensate destroys a binding energy of electron pairs and in turn so-called
superconductimg phase. As new result presented theory is that the number of the
superconducting bosons is not changed in the superconducting phase.


title:
A $O(\log m)$, deterministic, polynomial-time computable approximation
  of Lewis Carroll's scoring rule

abstract:
  We provide deterministic, polynomial-time computable voting rules that
approximate Dodgson's and (the ``minimization version'' of) Young's scoring
rules to within a logarithmic factor. Our approximation of Dodgson's rule is
tight up to a constant factor, as Dodgson's rule is $\NP$-hard to approximate
to within some logarithmic factor. The ``maximization version'' of Young's rule
is known to be $\NP$-hard to approximate by any constant factor. Both
approximations are simple, and natural as rules in their own right: Given a
candidate we wish to score, we can regard either its Dodgson or Young score as
the edit distance between a given set of voter preferences and one in which the
candidate to be scored is the Condorcet winner. (The difference between the two
scoring rules is the type of edits allowed.) We regard the marginal cost of a
sequence of edits to be the number of edits divided by the number of reductions
(in the candidate's deficit against any of its opponents in the pairwise race
against that opponent) that the edits yield. Over a series of rounds, our
scoring rules greedily choose a sequence of edits that modify exactly one
voter's preferences and whose marginal cost is no greater than any other such
single-vote-modifying sequence.


title:
Probabilistic computation of wind farm power generation based on wind
  turbine dynamic modeling

abstract:
  This paper addresses the problem of predicting a wind farm's power generation
when no or few statistical data is available. The study is based on a
time-series wind speed model and on a simple dynamic model of a DFIG wind
turbine including cut-off and cut-in behaviours. The wind turbine is modeled as
a stochastic hybrid system with three operation modes. Numerical results,
obtained using Monte-Carlo simulations, provide the annual distribution of a
wind farm's active power generation. For different numbers of wind turbines, we
compare the numerical results obtained using the dynamic model with those
obtained considering the wind turbine's steady-state power curve. Simulations
show that the wind turbine's dynamics do not need to be considered for
analyzing the annual distribution of a wind farm generation.


title: Theories of systems with limited information content

abstract:
  We introduce a hierarchical classification of theories that describe systems
with fundamentally limited information content. This property is introduced in
an operational way and gives rise to the existence of mutually complementary
measurements, i.e. a complete knowledge of future outcome in one measurement is
at the expense of complete uncertainty in the others. This is characteristic
feature of the theories and they can be ordered according to the number of
mutually complementary measurements which is also shown to define their
computational abilities. In the theories multipartite states may contain
entanglement and tomography with local measurements is possible. The
classification includes both classical and quantum theory and also generalized
probabilistic theories with higher number of degrees of freedom, for which
operational meaning is given. We also discuss thought experiments
discriminating standard quantum theory from the generalizations.


title:
Expanding translates of curves and Dirichlet-Minkowski theorem on linear
  forms

abstract:
  We show that a multiplicative form of Dirichlet's theorem on simultaneous
Diophantine approximation as formulated by Minkowski, cannot be improved for
almost all points on any analytic curve on R^k which is not contained in a
proper affine subspace. Such an investigation was initiated by Davenport and
Schmidt in the late sixties.
  The Diophantine problem is then settled by showing that certain sequence of
expanding translates of curves on the homogeneous space of unimodular lattices
in R^{k+1} gets equidistributed in the limit. We use Ratner's theorem on
unipotent flows, linearization techniques, and a new observation about
intertwined linear dynamics of various SL(m,R)'s contained in SL(k+1,R).


title:
Torsion points on elliptic curves over function fields and a theorem of
  Igusa

abstract:
  If F is a global function field of characteristic p>3, we employ Tate's
theory of analytic uniformization to give an alternative proof of a theorem of
Igusa describing the image of the natural Galois representation on torsion
points of non-isotrivial elliptic curves defined over F. Along the way, using
basic properties of Faltings heights of elliptic curves, we offer a detailed
proof of the function field analogue of a classical theorem of Shafarevich
according to which there are only finitely many F-isomorphism classes of
admissible elliptic curves defined over F with good reduction outside a fixed
finite set of places of F. We end the paper with an application to torsion
points rational over abelian extensions of F.


title: Coherent structures and isolated spectrum for Perron-Frobenius cocycles

abstract:
  We present an analysis of one-dimensional models of dynamical systems that
possess 'coherent structures'; global structures that disperse more slowly than
local trajectory separation. We study cocycles generated by expanding interval
maps and the rates of decay for functions of bounded variation under the action
of the associated Perron-Frobenius cocycles.
  We prove that when the generators are piecewise affine and share a common
Markov partition, the Lyapunov spectrum of the Perron-Frobenius cocycle has at
most finitely many isolated points. Moreover, we develop a strengthened version
of the Multiplicative Ergodic Theorem for non-invertible matrices and construct
an invariant splitting into Oseledets subspaces.
  We detail examples of cocycles of expanding maps with isolated Lyapunov
spectrum and calculate the Oseledets subspaces, which lead to an identification
of the underlying coherent structures.
  Our constructions generalise the notions of almost-invariant and
almost-cyclic sets to non-autonomous dynamical systems and provide a new
ensemble-based formalism for coherent structures in one-dimensional
non-autonomous dynamics.


title:
On the Quantization Procedure in Classical Mechanics and the Reality of
  Bohm's Psi-Field

abstract:
  Using Chetaev's theorem on stable trajectories in dynamics in the presence of
perturbation forces we obtain a generalized stability condition for Hamiltonian
systems that has the form of the Schrodinger equation. We show that the energy
of the perturbation forces generating generalized Chetaev's stability condition
is of electromagnetic nature and exactly coincides with Bohm's "quantum"
potential. We stress that not taking into account the reality of Bohm's
electromagnetic Psi-field turns out to be the fundamental reason of violation
of the famous Bell inequality, in the recent most precise direct experiments,
as well as in theoretical calculations based on the simple Wigner model. We
discuss the possibility of direct experiments, alternative to Bell's ideology
and related, e.g. with observation of nuclear stochastic resonance during the
alpha-decay process, which cannot occur in the framework of the probabilistic
interpretation of quantum mechanics, but has to occur in the alternative Bohm
interpretation.


title: Representations of quivers via reflection functors

abstract:
  These are the notes for a course on representations of quivers for second
year students in Paderborn in summer 2007. My aim was to provide a basic
introduction without using any advanced methods. It turns out that a good
knowledge of linear algebra is sufficient for proving Gabriel's theorem. Thus
we classify the quivers of finite representation type and study their
representations using reflection functors. Further material has been added
after giving this course in Bielefeld in summer 2010. This includes a
discussion of regular representations and wild phenomena. In particular, two
classical examples are covered: representations of the Kronecker quiver and
representations of the Klein four group.


title:
Temperature and final state effects in radio frequency spectroscopy
  experiments on atomic Fermi gases

abstract:
  We present a systematic characterization of the radio frequency (RF) spectra
of homogeneous, paired atomic Fermi gases at finite temperatures, $T$, in the
presence of final state interactions. The spectra, consisting of possible bound
states and positive as well as negative detuning ($\nu$) continua, satisfy
exactly the zeroth- and first-moment sum rules at all $T$. We show how to
detect the $\nu < 0$ continuum arising from thermally excited quasiparticles,
which has not yet been seen experimentally. We explain semi-quantitatively
recent RF experiments on "bound-bound" transitions and, thereby, predict the
associated effects of varying temperature.


title: Nonautonomous Kolmogorov parabolic equations with unbounded coefficients

abstract:
  We study a class of elliptic operators $A$ with unbounded coefficients
defined in $I\times\CR^d$ for some unbounded interval $I\subset\CR$. We prove
that, for any $s\in I$, the Cauchy problem $u(s,\cdot)=f\in C_b(\CR^d)$ for the
parabolic equation $D_tu=Au$ admits a unique bounded classical solution $u$.
This allows to associate an evolution family $\{G(t,s)\}$ with $A$, in a
natural way. We study the main properties of this evolution family and prove
gradient estimates for the function $G(t,s)f$. Under suitable assumptions, we
show that there exists an evolution system of measures for $\{G(t,s)\}$ and we
study the first properties of the extension of $G(t,s)$ to the $L^p$-spaces
with respect to such measures.


title: An asymptotic result for Brownian polymers

abstract:
  We consider a model of the shape of a growing polymer introduced by Durrett
and Rogers (Probab. Theory Related Fields 92 (1992) 337--349). We prove their
conjecture about the asymptotic behavior of the underlying continuous process
$X_t$ (corresponding to the location of the end of the polymer at time $t$) for
a particular type of repelling interaction function without compact support.


title:
Boundedness of Riesz transforms for elliptic operators on abstract
  Wiener spaces

abstract:
  Let (E,H,mu) be an abstract Wiener space and let D_V := VD, where D denotes
the Malliavin derivative and V is a closed and densely defined operator from H
into another Hilbert space G. Given a bounded operator B on G, coercive on the
closure of the range of V, we consider the realisation of the operator D_V* B
D_V in L^p(E,mu) for 1<p<\infty. Our main result states that the following
assertions are equivalent:
  (1) dom((sqrt(D_V* B D_V)) = dom(D_V) and Meyer's inequalities hold for D_V*
B D_V;
  (2) D_V D_V* B admits a bounded H-infinity calculus on the closure of the
range of D_V;
  (3) dom(sqrt(V*BV)) = dom(V) and Meyer's inequalities hold for V*BV;
  (4) VV*B admits a bounded H-infinity calculus on the closure of the range of
V.
  Moreover, if these conditions are satisfied, then dom(L) = dom(D_V^2) \cap
dom(D_A). The equivalence of (1)-(4) is a non-symmetric generalisation of the
classical Meyer inequalities (which correspond to the case G=H, V=I, B=I). A
one-sided version of the main result, giving L^p-boundedness of the associated
Riesz transforms in terms of a square function estimate, is also obtained.
  As an application let -A generate an analytic C_0-contraction semigroup on a
Hilbert space H and let -L be the L^p-realisation of the generator of its
second quantisation. Our results imply that two-sided bounds for the Riesz
transform of L are equivalent with the Kato square root property for A.


title:
Mode excitation Monte Carlo simulations of mesoscopically large
  membranes

abstract:
  Solvent-free coarse grained models represent one of the most promising
approaches for molecular simulations of mesoscopically large membranes. In
these models, the size of the simulated membrane is limited by the slow
relaxation time of longest bending mode. Here, we present a Monte Carlo
algorithm with update moves in which all the lipids are displaced
simultaneously. These collective moves result in fast excitation and relaxation
of the long wavelength thermal fluctuations. We apply the method to simulations
of a bilayer membrane of linear size $\sim 50 {\rm nm}$ and show reduction of
the relaxation time by two orders of magnitudes when compared to conventional
Monte Carlo.


title: Extreme flatness of normed modules and Arveson-Wittstock type theorems

abstract:
  We show in this paper that a certain class of normed modules over the algebra
of all bounded operators on a Hilbert space possesses a homological property
which is a kind of a functional-analytic version of the standard algebraic
property of flatness. We mean the preservation, under projective tensor
multiplication of modules, of the property of a given morphism to be isometric.
As an application, we obtain several extension theorems for different types of
modules, called Arveson-Wittstock type theorems. These, in their turn, have, as
a straight corollary, the `genuine' Arveson-Wittstock Theorem in its
non-matricial presentation. We recall that the latter theorem plays the role of
a `quantum' version of the classical Hahn-Banach theorem on the extension of
bounded linear functionals. It was originally proved by Wittstock (1981), and a
crucial preparatory step was done by Arveson (1969).


title: The Geometry of Interaction of Differential Interaction Nets

abstract:
  The Geometry of Interaction purpose is to give a semantic of proofs or
programs accounting for their dynamics. The initial presentation, translated as
an algebraic weighting of paths in proofnets, led to a better characterization
of the lambda-calculus optimal reduction. Recently Ehrhard and Regnier have
introduced an extension of the Multiplicative Exponential fragment of Linear
Logic (MELL) that is able to express non-deterministic behaviour of programs
and a proofnet-like calculus: Differential Interaction Nets. This paper
constructs a proper Geometry of Interaction (GoI) for this extension. We
consider it both as an algebraic theory and as a concrete reversible
computation. We draw links between this GoI and the one of MELL. As a
by-product we give for the first time an equational theory suitable for the GoI
of the Multiplicative Additive fragment of Linear Logic.


title: Ranking by Loops: a new approach to categorization

abstract:
  We introduce Loop Ranking, a new ranking measure based on the detection of
closed paths, which can be computed in an efficient way. We analyze it with
respect to several ranking measures which have been proposed in the past, and
are widely used to capture the relative importance of the vertices in complex
networks. We argue that Loop Ranking is a very appropriate measure to quantify
the role of both vertices and edges in the network traffic.


title: On countably compact 0-simple topological inverse semigroups

abstract:
  We describe the structure of 0-simple countably compact topological inverse
semigroups and the structure of congruence-free countably compact topological
inverse semigroups.


title: On linearly ordered $H$-closed topological semilattices

abstract:
  We give a criterium when a linearly ordered topological semilattice is
$H$-closed. We also prove that any linearly ordered $H$-closed topological
semilattice is absolutely $H$-closed and we show that every linearly ordered
semilattice is a dense subsemilattice of an $H$-closed topological semilattice.


title: Semigroup Closures of Finite Rank Symmetric Inverse Semigroups

abstract:
  We introduce the notion of semigroup with a tight ideal series and
investigate their closures in semitopological semigroups, particularly inverse
semigroups with continuous inversion. As a corollary we show that the symmetric
inverse semigroup of finite transformations $\mathscr{I}_\lambda^n$ of the rank
$\leqslant n$ is algebraically closed in the class of (semi)topological inverse
semigroups with continuous inversion. We also derive related results about the
nonexistence of (partial) compactifications of classes of semigroups that we
consider.


title: Adversary lower bounds for nonadaptive quantum algorithms

abstract:
  We present general methods for proving lower bounds on the query complexity
of nonadaptive quantum algorithms. Our results are based on the adversary
method of Ambainis.


title: On Kernelization of Supervised Mahalanobis Distance Learners

abstract:
  This paper focuses on the problem of kernelizing an existing supervised
Mahalanobis distance learner. The following features are included in the paper.
Firstly, three popular learners, namely, "neighborhood component analysis",
"large margin nearest neighbors" and "discriminant neighborhood embedding",
which do not have kernel versions are kernelized in order to improve their
classification performances. Secondly, an alternative kernelization framework
called "KPCA trick" is presented. Implementing a learner in the new framework
gains several advantages over the standard framework, e.g. no mathematical
formulas and no reprogramming are required for a kernel implementation, the
framework avoids troublesome problems such as singularity, etc. Thirdly, while
the truths of representer theorems are just assumptions in previous papers
related to ours, here, representer theorems are formally proven. The proofs
validate both the kernel trick and the KPCA trick in the context of Mahalanobis
distance learning. Fourthly, unlike previous works which always apply brute
force methods to select a kernel, we investigate two approaches which can be
efficiently adopted to construct an appropriate kernel for a given dataset.
Finally, numerical results on various real-world datasets are presented.


title: Super quantum mechanics, spacetime and quantum information

abstract:
  In the paper it is shown the connection between spacetime and quantum
information using an information spacetime as superspace. The connection of
quantum information with anticommuting variables is given . Also a solitonic
bag is presented where the information is confined.


title:
Notes on the mathematical basis of the UK Non-Native Organism Risk
  Assessment Scheme

abstract:
  Some problems with the mathematical analysis on which the UK Non-Native
Organism Risk Assessment Scheme is based are outlined.


title:
Quenched large deviations for multidimensional random walk in random
  environment: a variational formula

abstract:
  We take the point of view of the particle in a multidimensional nearest
neighbor random walk in random environment (RWRE). We prove a quenched large
deviation principle and derive a variational formula for the quenched rate
function. Most of the previous results in this area rely on the subadditive
ergodic theorem. We employ a different technique which is based on a minimax
theorem. Large deviation principles for RWRE have been proven for i.i.d.
nestling environments subject to a moment condition and for ergodic uniformly
elliptic environments. We assume only that the environment is ergodic and the
transition probabilities satisfy a moment condition.


title:
Combinatorial and model-theoretical principles related to regularity of
  ultrafilters and compactness of topological spaces. II

abstract:
  We find many conditions equivalent to the model-theoretical property $\lambda
\stackrel{\kappa}{\Rightarrow} \mu$ introduced in [L1].
  Our conditions involve uniformity of ultrafilters, compactness properties of
products of topological spaces and the existence of certain infinite matrices.


title: Super-Bridges Suspended Over Carbon Nanotube Cables

abstract:
  In this paper the new concept of super-bridges, i.e. kilometre-long bridges
suspended over carbon nanotube cables, is introduced. The analysis shows that
the use of realistic (thus defective) carbon nanotube bundles as suspension
cables can enlarge the current limit main span by a factor of 3.


title: Bayesian Analysis of Solar Oscillations

abstract:
  A Bayesian probability based approach is applied to the problem of detecting
and parameterizing oscillations in the upper solar atmosphere for the first
time. Due to its statistical origin, this method provides a mechanism for
determining the number of oscillations present, gives precise estimates of the
oscillation parameters with a self-consistent statistical error analysis, and
allows the oscillatory model signals to be reconstructed within these errors.
  A highly desirable feature of the Bayesian approach is the ability to resolve
oscillations with extremely small frequency separations. The code is applied to
SOHO/CDS (Solar and Heliospheric Observatory/Coronal Diagnostic Spectrometer) O
V 629A observations and resolves four distinct P4, P5, P6 and P7 p-modes within
the same sunspot transition region. This suggests that a spectrum of
photospheric p-modes is able to propagate into the upper atmosphere of the Sun
and Sun-like stars, and places precise observational constraints on models of
umbral eigen modes.


title: Fast k Nearest Neighbor Search using GPU

abstract:
  The recent improvements of graphics processing units (GPU) offer to the
computer vision community a powerful processing platform. Indeed, a lot of
highly-parallelizable computer vision problems can be significantly accelerated
using GPU architecture. Among these algorithms, the k nearest neighbor search
(KNN) is a well-known problem linked with many applications such as
classification, estimation of statistical properties, etc. The main drawback of
this task lies in its computation burden, as it grows polynomially with the
data size. In this paper, we show that the use of the NVIDIA CUDA API
accelerates the search for the KNN up to a factor of 120.


title: On chains in $H$-closed topological pospaces

abstract:
  We study chains in an $H$-closed topological partially ordered space. We give
sufficient conditions for a maximal chain $L$ in an $H$-closed topological
partially ordered space such that $L$ contains a maximal (minimal) element.
Also we give sufficient conditions for a linearly ordered topological partially
ordered space to be $H$-closed. We prove that any $H$-closed topological
semilattice contains a zero. We show that a linearly ordered $H$-closed
topological semilattice is an $H$-closed topological pospace and show that in
the general case this is not true. We construct an example an $H$-closed
topological pospace with a non-$H$-closed maximal chain and give sufficient
conditions that a maximal chain of an $H$-closed topological pospace is an
$H$-closed topological pospace.


title: Proposed experiment for testing quantum contextuality with neutrons

abstract:
  We show that an experimental demonstration of quantum contextuality using 2
degrees of freedom of single neutrons based on a violation of an inequality
derived from the Peres-Mermin proof of the Kochen-Specker theorem would be more
conclusive than those obtained from previous experiments involving pairs of
ions [M. A. Rowe et al., Nature (London) 409, 791 (2001)] and single neutron
[Y. Hasegawa et al., Nature (London) 425, 45 (2003)] based on violations of
Clauser-Horne-Shimony-Holt-like inequalities.


title: Bosonic CNOT gates with Quantum Interrogation

abstract:
  We put forward a new CNOT gate scheme with atoms and ions based on quantum
interrogation and a bosonic particle extension of the models of linear optics
quantum computation. We show how the possibility of particle collision can
provide the strong interaction that is needed for universal quantum gates. Two
atom optics proposals are provided. Unlike previous schemes, these gates are at
the same time nondestructive, valid for arbitrary inputs and can work with a
probability as close to unity as desired in the lossless case. Data is encoded
into position modes and the gates only require basic atom optics elements,
which gives potentially simpler quantum computer implementations.


title: Chiral transition in a strong magnetic background

abstract:
  The presence of a strong magnetic background can modify the nature and the
dynamics of the chiral phase transition at finite temperature. We compute the
modified effective potential in the linear sigma model with quarks to one loop
in the $\bar{MS}$ scheme for $N_{f}=2$. For fields $eB\sim 5 m_{\pi}^{2}$ and
larger a crossover is turned into a weak first-order transition. We discuss
possible implications for non-central heavy ion collisions at RHIC and LHC, and
for the primordial QCD transition.


title:
Macroscopic Quantum Superposition and Entanglement in light reflection
  from Bose-Einstein Condensates

abstract:
  The multiphoton quantum superposition generated by a quantum-injected optical
parametric amplifier (QI-OPA) seeded by a single-photon belonging to an EPR
entangled pair is made to interact with a Mirror-BEC shaped as a Bragg
interference structure. The effect can be greatly enhanced if the mirror is
part of a cavity structure or is used within an optical interferometer. The
overall process will realize an Entangled Macroscopic Quantum Superposition
involving a ''microscopic'' singe-photon state of polarization and the coherent
''macroscopic'' displacement of the BEC structure acting in space-like
separated distant places.


title:
Direct Measurements of Absolute Branching Fractions for D0 and D+
  Inclusive Semimuonic Decays

abstract:
  By analyzing about 33 $\rm pb^{-1}$ data sample collected at and around 3.773
GeV with the BES-II detector at the BEPC collider, we directly measure the
branching fractions for the neutral and charged $D$ inclusive semimuonic decays
to be $BF(D^0 \to \mu^+ X) =(6.8\pm 1.5\pm 0.7)%$ and $BF(D^+ \to \mu^+ X)
=(17.6 \pm 2.7 \pm 1.8)%$, and determine the ratio of the two branching
fractions to be $\frac{BF(D^+ \to \mu^+ X)}{BF(D^0 \to \mu^+ X)}=2.59\pm 0.70
\pm 0.25$.


title:
Sequential melting of charmonium states in an expanding Quark Gluon
  Plasma and $J/\psi$ suppression at RHIC and LHC energy collisions

abstract:
  We have developed a hydrodynamic model to study sequential melting of
charmonium states in an expanding QGP medium. According to the initial fluid
temperature profile, $J/\psi$'s are randomly distributed in the transverse
plane. As the fluid evolve in time, the free streaming $J/\psi$'s are
suppressed if the local fluid temperature exceed a critical temperature. PHENIX
data on the centrality dependence of $J/\psi$ suppression in Au+Au collisions
at mid-rapidity are explained by sequential melting of the charmonium states,
$\chi_c$, $\psi\prime$ and $J/\psi$, in the expanding medium. The critical
temperatures $T_{J/\psi} \approx2.09T_c$ and $T_\chi=T_{\chi_c}=T_{\psi\prime}
\approx 1.1T_c$ agree with lattice motivated calculations. The feed-down
fraction $F$ depend on whether the cold nuclear matter effect is included or
not. It changes from $F=0.3$ with cold nuclear matter effect included to
$F=0.5$ when the effect is neglected. Model fails to reproduce the PHENIX data
on the centrality dependence of $J/\psi$ suppression in Cu+Cu collisions at
mid-rapidity, indicating that the mechanism of $J/\psi$ suppression is
different in Au+Au and in Cu+Cu collisions. We also use the model to predict
for the centrality dependence of $J/\psi$ suppression in Pb+Pb collisions at
LHC energy, $\sqrt{s}$=5500 GeV. In LHC energy, $J/\psi$'s are more suppressed
in mid central collisions than in Au+Au collisions at RHIC energy.


title: Cluster algebras and semipositive symmetrizable matrices

abstract:
  In this paper, we give a description of the skew-symmetrizable matrices and
their mutation classes which are determined by the generalized Cartan matrices
of affine type.


title:
Dynamics of large anisotropic spin in a sub-ohmic dissipative
  environment close to a quantum-phase transition

abstract:
  We investigate the dynamics of a large anisotropic spin whose easy-axis
component is coupled to a bosonic bath with a spectral function $J(\w)\propto
\omega^s$. Such a spin complex might be realized in a single-molecular magnet.
Using the non-perturbative renormalization group, we calculate the line of
quantum-phase transitions in the sub-ohmic regime ($s<1$). These quantum-phase
transitions only occur for integer spin $J$. For half-integer $J$, the low
temperature fixed-point is identical to the fixed-point of the spin-boson model
without quantum-tunneling between the two levels. Short-time coherent
oscillations in the spin decay prevail even into the localized phase in the
sub-ohmic regime. The influence of the reorganization energy and the recurrence
time on the decoherence in the absence of quantum-tunneling is discussed.


title:
The Second Survey of the Molecular Clouds in the Large Magellanic Cloud
  by NANTEN I: Catalog of Molecular Clouds

abstract:
  The second survey of the molecular clouds in 12CO (J = 1-0) was carried out
in the Large Magellanic Cloud by NANTEN. The sensitivity of this survey is
twice as high as that of the previous NANTEN survey, leading to a detection of
molecular clouds with M_CO > 2 x 10^4 M_sun. We identified 272 molecular
clouds, 230 of which are detected at three or more observed positions. We
derived the physical properties, such as size, line width, virial mass, of the
164 GMCs which have an extent more than the beam size of NANTEN in both the
major and minor axes. The CO luminosity and virial mass of the clouds show a
good correlation of M_VIR propto L_CO^{1.1 +- 0.1} with a Spearman rank
correlation of 0.8 suggesting that the clouds are in nearly virial equilibrium.
Assuming the clouds are in virial equilibrium, we derived an X_CO-factor to be
~ 7 x 10^20 cm^-2 (K km s^-1)^-1. The mass spectrum of the clouds is fitted
well by a power law of N_cloud(>M_CO) proportional to M_CO^{-0.75 +- 0.06}
above the completeness limit of 5 x 10^4 M_sun. The slope of the mass spectrum
becomes steeper if we fit only the massive clouds; e.g., N_cloud (>M_CO) is
proportional to M_CO^{-1.2 +- 0.2} for M_CO > 3 x 10^5 M_sun.


title:
Quantum Phase Transition Induced by a Preformed Pair in a Boson-Fermion
  Model of Fulleride Superconductivity

abstract:
  There continues to be enormous interest in the BCS to BEC transition as there
still is no exact theory. We recently reported a revealing reinterpretation of
the condensed phase Boson-Fermion Model (BFM) by comparing it to a cold atom
formulation [1]. While the ground and singly excited states appear to remain
continuous in all models we have examined, the collective modes contain a
singularity due to a Feshbach resonance (tuned by doping) causing a breakdown
of the Migdal theorem. As a result of vertex corrections, there is a
fundamental change in the nature of the superconductivity due to the formation
of preformed pairs as the previously suggested location [1] of a quantum
critical point in the fulleride phase diagram is passed. The result is a
quantum phase transition (QPT) between BCS and BEC-like (or Feshbach resonance)
superconductivity (SC).
  We discuss features of the resonance and the role of the experimentally
observed preformed pair formation in fullerides, essential to the Boson-Fermion
Model (BFM), and often speculated since the work of Nozieres and Schmitt-Rink
[17]. Here, we present arguments to establish a model of the preformed pair
which can be favorably compared to a circular charge density wave (CDW)
isolated on a fulleride molecule. The binding is much larger than a Cooper
pair. The CDW seems to be stabalized by splitting of the Jahn-Teller active
vibrational modes to reduce Coulomb repulsions. Our conclusions are: 1) the
doping of two electrons into triply degenerate orbitals results in the
experimentally observed singlet state (CDW); and 2) this CDW (preformed pair)
has a dual role as doping is varied: suppression of BCS SC and enabling a
Feshbach resonance form of SC.


title: Monads and comonads in module categories

abstract:
  Let $A$ be a ring and $\M_A$ the category of $A$-modules. It is well known in
module theory that for any $A $-bimodule $B$, $B$ is an $A$-ring if and only if
the functor $-\otimes_A B: \M_A\to \M_A$ is a monad (or triple).
  Similarly, an $A $-bimodule $\C$ is an $A$-coring provided the functor
$-\otimes_A\C:\M_A\to \M_A$ is a comonad (or cotriple). The related categories
of modules (or algebras) of $-\otimes_A B$ and comodules (or coalgebras) of
$-\otimes_A\C$ are well studied in the literature. On the other hand, the right
adjoint endofunctors $\Hom_A(B,-)$ and $\Hom_A(\C,-)$ are a comonad and a
monad, respectively, but the corresponding (co)module categories did not find
much attention so far. The category of $\Hom_A(B,-)$-comodules is isomorphic to
the category of $B$-modules, while the category of $\Hom_A(\C,-)$-modules
(called $\C$-contramodules by Eilenberg and Moore) need not be equivalent to
the category of $\C$-comodules.
  The purpose of this paper is to investigate these categories and their
relationships based on some observations of the categorical background. This
leads to a deeper understanding and characterisations of algebraic structures
such as corings, bialgebras and Hopf algebras. For example, it turns out that
the categories of $\C$-comodules and $\Hom_A(\C,-)$-modules are equivalent
provided $\C$ is a coseparable coring. Furthermore, a bialgebra
  $H$ over a commutative ring $R$ is a Hopf algebra if and only if $\Hom_R(H-)$
is a Hopf bimonad on $\M_R$ and in this case the categories of $H$-Hopf modules
and mixed $\Hom_R(H,-)$-bimodules are both equivalent to $\M_R$.


title:
Stabilit\'{e} du comportement des marches al\'{e}atoires sur un groupe
  localement compact

abstract:
  Dans cet article nous d\'{e}montrons un th\'{e}or\`{e}me de stabilit\'{e} des
probabilit\'{e}s de retour sur un groupe localement compact unimodulaire,
s\'{e}parable et compactement engendr\'{e}. Nous d\'{e}montrons que le
comportement asymptotique de $F^{*(2n)}(e)$ ne d\'{e}pend pas de la densit\'{e}
$F$ sous des hypoth\`{e}ses naturelles. A titre d'exemple nous \'{e}tablissons
que la probabilit\'{e} de retour sur une large classe de groupes r\'{e}solubles
se comporte comme $\exp(-n^{1/3})$.


title: Ising model with memory: coarsening and persistence properties

abstract:
  We consider the coarsening properties of a kinetic Ising model with a memory
field. The probability of a spin-flip depends on the persistence time of the
spin in a state. The more a spin has been in a given state, the less the
spin-flip probability is. We numerically studied the growth and persistence
properties of such a system on a two dimensional square lattice. The memory
introduces energy barriers which freeze the system at zero temperature. At
finite temperature we can observe an apparent arrest of coarsening for low
temperature and long memory length. However, since the energy barriers
introduced by memory are due to local effects, there exists a timescale on
which coarsening takes place as for the Ising model. Moreover the two point
correlation functions of the Ising model with and without memory are the same,
indicating that they belong to the same universality class.


title:
Slowly rocking symmetric, spatially periodic Hamiltonians: The role of
  escape and the emergence of giant transient directed transport

abstract:
  The nonintegrable Hamiltonian dynamics of particles placed in a symmetric,
spatially periodic potential and subjected to a periodically varying field is
explored. Such systems can exhibit a rich diversity of unusual transport
features. In particular, depending on the setting of the initial phase of the
drive, the possibility of a giant transient directed transport in a symmetric,
space-periodic potential when driven with an adiabatically varying field
arises. Here, we study the escape scenario and corresponding mean escape times
of particles from a trapping region with the subsequent generation of a
transient directed flow of an ensemble of particles. It is shown that for
adiabatically slow inclination modulations the unidirectional flow proceeds
over giant distances. The direction of escape and, hence, of the flow is
entirely governed whether the periodic force, modulating the inclination of the
potential, starts out initially positive or negative. In the phase space, this
transient directed flow is associated with a long-lasting motion taking place
within ballistic channels contained in the non-uniform chaotic layer. We
demonstrate that for adiabatic modulations all escaping particles move
ballistically into the same direction, leading to a giant directed current.


title:
Critical gravitational collapse: towards a holographic understanding of
  the Regge region

abstract:
  We study the possible holographic connection between the Regge limit in QCD
and critical gravitational collapse of a perfect fluid in higher dimensions. We
begin by analyzing the problem of critical gravitational collapse of a perfect
fluid in any number of dimensions and numerically compute the associated
Choptuik exponent in d=5, 6 and 7 for a range of values of the speed of sound
of the fluid. Using continuous self-similarity as guiding principle, a
holographic correspondence between this process and the phenomenon of parton
saturation in high-energy scattering in QCD is proposed. This holographic
connection relates strong gravitational physics in the bulk with
(nonsupersymmetric) QCD at weak coupling in four dimensions.


title: Charge-induced conformational changes of dendrimers

abstract:
  We study the effect of chargeable monomers on the conformation of dendrimers
of low generation by computer simulations, employing bare Coulomb interactions.
The presence of the latter leads to an increase in size of the dendrimer due to
a combined effect of electrostatic repulsion and the presence of counterions
within the dendrimer, and also enhances a shell-like structure for the monomers
of different generations. In the resulting structures the bond-length between
monomers, especially near the center, will increase to facilitate a more
effective usage of space in the outer-regions of the dendrimer.


title:
Neutrino oscillograms of the Earth: effects of 1-2 mixing and
  CP-violation

abstract:
  We develop a comprehensive description of three flavor neutrino oscillations
inside the Earth in terms of neutrino oscillograms in the whole range of nadir
angles and for energies above 0.1 GeV. The effects of the 1-2 mass splitting
and mixing as well the interference of the 1-2 and 1-3 modes of oscillations
are quantified. The 1-2 mass splitting and mixing lead to the appearance, apart
from the resonance MSW peaks, of the parametric resonance peak for
core-crossing trajectories at E_nu ~= 0.2 GeV. We show that the interference
effects, in particular CP violation, have a domain structure with borders
determined by the solar and atmospheric magic lines and the lines of the
interference phase condition. The dependence of the oscillograms on the Dirac
CP-violating phase is studied. We show that for sin^2(2 theta13) < 0.1 the
strongest dependence of the oscillograms on delta is in the 1-2 and 1-3
resonance regions.


title: Kinematical Analysis of a Sample of Bipolar Planetary Nebulae

abstract:
  We present the kinematics of a sample of bipolar planetary nebulae (PNe)
which cover a wide range of observed morphologies and collimation degrees, from
bipolar PNe with a marked equatorial ring and wide lobes to highly collimated
objects. We use an empirical model in order to derive the expansion velocity,
collimation degree, and inclination angle of the PN with respect to the plane
of the sky. The equatorial expansion velocities measured in the objects in our
sample are always in the low to medium range (3-16km/s),while their polar
expansion velocities range from low to very high (18-100 km/s). None of the
objects in our sample, even those that show an extreme collimation degree, seem
to be (kinematically) younger than ~1000 yr. We compare our results with the
state-of-the-art theoretical models for the formation of bipolar PNe. We find
good agreement between the observed expansion velocities and numerical models
that use magnetic fields with stellar rotation as collimation mechanism.


title:
On Semi-Modular Subalgebras of Lie Algebras Over Fields of Arbitrary
  Characteristic

abstract:
  This paper is a further contribution to the extensive study by a number of
authors of the subalgebra lattice of a Lie algebra. It is shown that, in
certain circumstances, including for all solvable algebras, for all Lie
algebras over algebraically closed fields of characteristic p > 0 that have
absolute toral rank less than or equal to 1 or are restricted, and for all Lie
algebras having the one-and-a-half generation property, the conditions of
modularity and semi-modularity are equivalent, but that the same is not true
for all Lie algebras over a perfect field of characteristic three. Semi-modular
subalgebras of dimensions one and two are characterised over (perfect, in the
case of two-dimensional subalgebras) fields of characteristic different from 2,
3.


title: Near threshold ppbar enhancement in the J/psi -> omega ppbar decay

abstract:
  The near-threshold behavior of the ppbar invariant mass spectrum from the
J/psi -> omega ppbar decay reported recently by the BES Collaboration is
analyzed. Contrary to the statement made by the BES Collaboration itself our
study demonstrates that there is indeed a noticeable enhancement in the ppbar
invariant mass spectrum near threshold. Moreover, this enhancement is nicely
reproduced by the final state interaction in the relevant 11S0 ppbar partial
wave as given by the Julich nucleon--antinucleon model. Therefore, and again
contrary to the statement by the BES Collaboration, their new data on J/psi ->
omega ppbar decay in fact strongly support the FSI interpretation of the ppbar
enhancement, seen also in other decay reactions.


title: Homotopy exponents for large H-spaces

abstract:
  We show that H-spaces with finitely generated cohomology, as an algebra or as
an algebra over the Steenrod algebra, have homotopy exponents at all primes.
This provides a positive answer to a question of Stanley.


title: Nonequilibrium spin glass dynamics from picoseconds to 0.1 seconds

abstract:
  We study numerically the nonequilibrium dynamics of the Ising Spin Glass, for
a time that spans eleven orders of magnitude, thus approaching the
experimentally relevant scale (i.e. {\em seconds}). We introduce novel analysis
techniques that allow to compute the coherence length in a model-independent
way. Besides, we present strong evidence for a replicon correlator and for
overlap equivalence. The emerging picture is compatible with non-coarsening
behavior.


title: Dynamics of spin and orbital phase transitions in YVO3

abstract:
  YVO3 exhibits a well separated sequence of orbital and spin order transitions
at 200 K and 116 K, followed by a combined spin-orbital reorientation at 77 K.
It is shown that the spin order can be destroyed by a sufficiently strong
optical pulse within less than 4 ps. In contrast, the orbital reordering
transition from C-type to G-type orbital order is slower than 100 ps and goes
via an intermediate nonthermal phase. We propose that the dynamics of phase
transitions is subjected to symmetry relations between the associated phases.


title:
Very High Energy gamma-ray observations of Mrk 501 using TACTIC imaging
  gamma-ray telescope during 2005-06

abstract:
  In this paper we report on the Markarian 501 results obtained during our TeV
$\gamma$-ray observations from March 11 to May 12, 2005 and February 28 to May
7, 2006 for 112.5 hours with the TACTIC $\gamma$-ray telescope. During 2005
observations for 45.7 hours, the source was found to be in a low state and we
have placed an upper limit of 4.62 $\times$ 10$^{-12}$ photons cm$^{-2}$
s$^{-1}$ at 3$\sigma$ level on the integrated TeV $\gamma$-ray flux above 1 TeV
from the source direction. However, during the 2006 observations for 66.8h,
detailed data analysis revealed the presence of a TeV $\gamma$-ray signal from
the source with a statistical significance of 7.5$\sigma$ above
$E_{\gamma}\geq$ 1 TeV. The time averaged differential energy spectrum of the
source in the energy range 1-11 TeV is found to match well with the power law
function of the form ($d\Phi/dE=f_0 E^{-\Gamma}$) with $f_0=(1.66\pm0.52)\times
10^{-11}cm^{-2}s^{-1}TeV^{-1}$ and $\Gamma=2.80\pm0.27$.


title:
Properties of Fractional Exclusion Statistics in Interacting Particle
  Systems

abstract:
  We show that fractional exclusion statistics is manifested in general in
interacting systems and we discuss the conjecture recently introduced (J. Phys.
A: Math. Theor. 40, F1013, 2007), according to which if in a thermodynamic
system the mutual exclusion statistics parameters are not zero, then they have
to be proportional to the dimension of the Hilbert space on which they act. By
using simple, intuitive arguments, but also concrete calculations in
interacting systems models, we show that this conjecture is not some abstract
consequence of unphysical modeling, but is a natural--and for a long time
overlooked--property of fractional exclusion statistics. We show also that the
fractional exclusion statistics is the consequence of interaction between the
particles of the system and it is due to the change from the description of the
system in terms of free-particle energies, to the description in terms of the
quasi-particle energies. From this result, the thermodynamic equivalence of
systems of the same, constant density of states, but any exclusion statistics
follows immediately.


title:
Conformal sector of Quantum Einstein Gravity in the local potential
  approximation: non-Gaussian fixed point and a phase of unbroken
  diffeomorphism invariance

abstract:
  We explore the nonperturbative renormalization group flow of Quantum Einstein
Gravity (QEG) on an infinite dimensional theory space. We consider "conformally
reduced" gravity where only fluctuations of the conformal factor are quantized
and employ the Local Potential Approximation for its effective average action.
The requirement of "background independence" in quantum gravity entails a
partial differential equation governing the scale dependence of the potential
for the conformal factor which differs significantly from that of a scalar
matter field. In the infinite dimensional space of potential functions we find
a Gaussian as well as a non-Gaussian fixed point which provides further
evidence for the viability of the asymptotic safety scenario. The analog of the
invariant cubic in the curvature which spoils perturbative renormalizability is
seen to be unproblematic for the asymptotic safety of the conformally reduced
theory. The scaling fields and dimensions of both fixed points are obtained
explicitly and possible implications for the predictivity of the theory are
discussed. Spacetime manifolds with $R^d$ as well as $S^d$ topology are
considered. Solving the flow equation for the potential numerically we obtain
examples of renormalization group trajectories inside the ultraviolet critical
surface of the non-Gaussian fixed point. The quantum theories based upon some
of them show a phase transition from the familiar (low energy) phase of gravity
with spontaneously broken diffeomorphism invariance to a new phase of unbroken
diffeomorphism invariance; the latter phase is characterized by a vanishing
expectation value of the metric.


title:
Theoretical status and prospects for top-quark pair production at hadron
  colliders

abstract:
  We present an update of the theoretical predictions for the cross section of
top-quark pair production at Tevatron and LHC. In particular we employ
improvements due to soft gluon resummation at next-to-next-to-leading
logarithmic accuracy. We expand the resummed results and derive analytical
finite-order cross sections through next-to-next-to-leading order which are
exact in all logarithmically enhanced terms near threshold. These results are
the best present estimates for the top-quark pair production cross section. We
investigate the scale dependence as well as the sensitivity on the parton
luminosities.


title:
Finding ultracool brown dwarfs with MegaCam on CFHT: method and first
  results

abstract:
  We present the first results of a wide field survey for cool brown dwarfs
with the MegaCam camera on the CFHT telescope, the Canada-France Brown Dwarf
Survey, hereafter CFBDS. Our objectives are to find ultracool brown dwarfs and
to constrain the field-brown dwarf mass function thanks to a larger sample of L
and T dwarfs. We identify candidates in CFHT/MegaCam i' and z' images using
optimised psf-fitting within Source Extractor, and follow them up with pointed
near-infrared imaging on several telescopes. We have so far analysed over 350
square degrees and found 770 brown dwarf candidates brighter than z'{AB}=22.5.
We currently have J-band photometry for 220 of these candidates, which confirms
37% as potential L or T dwarfs. Some are among the reddest and farthest brown
dwarfs currently known, including an independent identification of the recently
published ULAS J003402.77-005206.7 and the discovery of a second brown dwarf
later than T8, CFBDS J005910.83-011401.3. Infrared spectra of three T dwarf
candidates confirm their nature, and validate the selection process. The
completed survey will discover ~100 T dwarfs and ~500 L dwarfs or M dwarfs
later than M8, approximately doubling the number of currently known brown
dwarfs. The resulting sample will have a very well-defined selection function,
and will therefore produce a very clean luminosity function.


title: Small-tau expansion for the form factor of glued quantum star graphs

abstract:
  We compute the small-tau expansion up to the third order for the form factor
of two glued quantum star graphs with Neumann boundary conditions, by taking
into account only the most backscattering orbits. We thus show that the glueing
has no effect if the number of glueing edges is negligible compared to the
number of edges of the graph, whereas it has an effect on the $\tau^2$ term
when the numbers of glueing and non glueing edges are of the same order.


title: On Exponential Stability for Skew-Evolution Semiflows on Banach Spaces

abstract:
  The paper emphasizes the property of stability for skew-evolution semiflows
on Banach spaces, defined by means of evolution semiflows and evolution
cocycles and which generalize the concept introduced by us in a previous paper.
There are presented several general characterizations of this asymptotic
property out of which can be deduced well known results of the stability
theory. A unified treatment in the uniform and in the nonuniform setting is
given. The main results are also formulated in discrete time.


title:
Femtosecond and Ultraviolet Laser Irradiation of Graphite-Like Hexagonal
  Boron Nitride

abstract:
  Effect of the femtosecond and nanosecond UV laser irradiation (below the
ablation threshold) of graphite-like hexagonal boron nitride (hBN) has been
studied. Experiments were carried out with the compacted powder under high
vacuum at room temperature using excimer KrF laser (248 nm). In the nanosecond
operation mode, the laser-induced fluorescence spectra are found strongly
modified depending on the integrated doze, which is attributed to a progressive
enrichment of the surface layer by elemental boron. A slow sample recovery
after the laser irradiation has been observed. On the other hand, in the
femtosecond mode the fluorescence spectra depend on the laser fluence, and the
changes are reversible: low energy fluorescence spectra are restored
immediately when the laser energy decreases. This effect can be explained by a
material bleaching, which favors a bulk centers emission. The ablation
threshold has been determined as 78 mJ/cm2 in the femtosecond laser operational
mode.


title:
Anisotropic interaction of two-level systems with acoustic waves in
  disordered crystals

abstract:
  We apply the model introduced in Phys. Rev. B 75, 064202 (2007),
cond-mat/0610469, to calculate the anisotropy effect in the interaction of two
level systems with phonons in disordered crystals. We particularize our
calculations to cubic crystals and compare them with the available experimental
data to extract the parameters of the model. With these parameters we calculate
the interaction of the dynamical defects in the disordered crystal with phonons
(or sound waves) propagating along other crystalographic directions, providing
in this way a method to investigate if the anisotropy comes from the two-level
systems being preferably oriented in a certain direction or solely from the
lattice anisotropy with the two-level systems being isotropically oriented.


title:
Dynamical Casimir effect for a massless scalar field between two
  concentric spherical shells

abstract:
  In this work we consider the dynamical Casimir effect for a massless scalar
field -- under Dirichlet boundary conditions -- between two concentric
spherical shells. We obtain a general expression for the average number of
particle creation, for an arbitrary law of radial motion of the spherical
shells, using two distinct methods: by computing the density operator of the
system and by calculating the Bogoliubov coefficients. We apply our general
expression to breathing modes: when only one of the shells oscillates and when
both shells oscillate in or out of phase. We also analyze the number of
particle production and compare it with the results for the case of plane
geometry.


title:
Electric field control of spin-orbit splittings in GaAs/AlGaAs coupled
  quantum wells

abstract:
  Electron spin dynamics is investigated in n-i-n GaAs/AlGaAs coupled quantum
wells. The electron spin dephasing time is measured as a function of an
external electrical bias under resonant excitation of the 1sHH intrawell
exciton using a time-resolved Kerr rotation technique. It is found a strong
electron spin dephasing time anisotropy caused by an interference of the
structure inversion asymmetry and the bulk inversion asymmetry. This anisotropy
is shown to be controlled by an electrical bias. A theoretical analysis of
electron spin dephasing time anisotropy is developed. The ratio of Rashba and
Dresselhaus spin splittings is studied as a function of applied bias.


title:
Microscopic models and effective equation of state in nuclear collisions
  at FAIR energies

abstract:
  Two microscopic models, UrQMD and QGSM, were employed to study the formation
of locally equilibrated hot and dense nuclear matter in heavy-ion collisions at
energies from 11.6 AGeV to 160 AGeV. Analysis was performed for the fixed
central cubic cell of volume V = 125 fm**3 and for the expanding cell which
followed the growth of the central area with uniformly distributed energy. To
decide whether or not the equilibrium was reached, results of the microscopic
calculations were compared to that of the statistical thermal model. Both
dynamical models indicate that the state of kinetic, thermal and chemical
equilibrium is nearly approached at any bombarding energy after a certain
relaxation period. The higher the energy, the shorter the relaxation time.
Equation of state has a simple linear dependence P = a(sqrt{s})*e, where a =
c_s**2 is the sound velocity squared. It varies from 0.12 \pm 0.01 at E_{lab} =
11.6 AGeV to 0.145 \pm 0.005 at E_{lab} = 160 AGeV. Change of the slope in
a(sqrt{s}) behavior occurs at E_{lab} = 40 AGeV and can be assigned to the
transition from baryon-rich to meson-dominated matter. The phase diagrams in
the T - mu_B plane show the presence of kinks along the lines of constant
entropy per baryon. These kinks are linked to the inelastic (i.e. chemical)
freeze-out in the system.


title:
A Littelmann path model for crystals of Generalized Kac-Moody algebras
  revisited

abstract:
  A Littelmann path model is constructed for crystals pertaining to a not
necessarily symmetrizable Borcherds-Cartan matrix. Here one must overcome
several combinatorial problems coming from the imaginary simple roots. The main
results are an isomorphism theorem and a character formula of
Borcherds-Kac-Weyl type for the crystals. In the symmetrizable case, the
isomorphism theorem implies that the crystals constructed by this path model
coincide with those of Jeong, Kang, Kashiwara and Shin obtained by taking the
limit at q=0 in the quantized enveloping algebra.


title: Scattering of phonons on two-level systems in disordered crystals

abstract:
  We calculate the scattering rates of phonons on two-level systems in
disordered trigonal and hexagonal crystals. We apply a model in which the
two-level system, characterized by a direction in space, is coupled to the
strain field of the phonon via a tensor of coupling constants. The structure of
the tensor of coupling constants is similar to the structure of the tensor of
elastic stiffness constants, in the sense that they are determined by the same
symmetry transformations. In this way, we emphasize the anisotropy of the
interaction of elastic waves with the ensemble of two-level systems in
disordered crystals. We also point to the fact that the ratio
$\gamma_l/\gamma_t$ has a much broader range of allowed values in disordered
crystals than in isotropic solids.


title: The SDSS Discovery of a Strongly Lensed Post-Starburst Galaxy at z=0.766

abstract:
  We present the first result of a survey for strong galaxy-galaxy lenses in
Sloan Digital Sky Survey (SDSS) images. SDSS J082728.70+223256.4 was selected
as a lensing candidate using selection criteria based on the color and
positions of objects in the SDSS photometric catalog. Follow-up imaging and
spectroscopy showed this object to be a lensing system. The lensing galaxy is
an elliptical at z = 0.349 in a galaxy cluster. The lensed galaxy has the
spectrum of a post-starburst galaxy at z = 0.766. The lensing galaxy has an
estimated mass of $\sim 1.2 \times 10^{12} M_{\odot}$ and the corresponding
mass to light ratio in the B-band is $\sim 26 M_{\odot}/L_{\odot}$ inside 1.1
effective radii of the lensing galaxy. Our study shows how catalogs drawn from
multi-band surveys can be used to find strong galaxy-galaxy lenses having
multiple lens images. Our strong lensing candidate selection based on
photometry-only catalogs will be useful in future multi-band imaging surveys
such as SNAP and LSST.


title:
Strictly and asymptotically scale-invariant probabilistic models of $N$
  correlated binary random variables having {\em q}--Gaussians as $N\to \infty$
  limiting distributions

abstract:
  In order to physically enlighten the relationship between {\it
$q$--independence} and {\it scale-invariance}, we introduce three types of
asymptotically scale-invariant probabilistic models with binary random
variables, namely (i) a family, characterized by an index $\nu=1,2,3,...$,
unifying the Leibnitz triangle ($\nu=1$) and the case of independent variables
($\nu\to\infty$); (ii) two slightly different discretizations of
$q$--Gaussians; (iii) a special family, characterized by the parameter $\chi$,
which generalizes the usual case of independent variables (recovered for
$\chi=1/2$). Models (i) and (iii) are in fact strictly scale-invariant. For
models (i), we analytically show that the $N \to\infty$ probability
distribution is a $q$--Gaussian with $q=(\nu -2)/(\nu-1)$. Models (ii) approach
$q$--Gaussians by construction, and we numerically show that they do so with
asymptotic scale-invariance. Models (iii), like two other strictly
scale-invariant models recently discussed by Hilhorst and Schehr (2007),
approach instead limiting distributions which are {\it not} $q$--Gaussians. The
scenario which emerges is that asymptotic (or even strict) scale-invariance is
not sufficient but it might be necessary for having strict (or asymptotic)
$q$--independence, which, in turn, mandates $q$--Gaussian attractors.


title: On certain enumeration problems in two-dimensional topology

abstract:
  We announce a solution to several enumeration problems in topology of
surfaces. This includes an enumeration of homotopy classes of sections of
locally trivial fiber bundles over surfaces and a computation of non-abelian
1-cohomology of surfaces.


title: Distributed Space-Time Block Codes for the MIMO Multiple Access Channel

abstract:
  In this work, the Multiple transmit antennas Multiple Access Channel is
considered. A construction of a family of distributed space-time codes for this
channel is proposed. No Channel Side Information at the transmitters is assumed
and users are not allowed to cooperate together. It is shown that the proposed
code achieves the Diversity Multiplexing Tradeoff of the channel. As an
example, we consider the two-user MIMO-MAC channel. Simulation results show the
significant gain offered by the new coding scheme compared to an orthogonal
transmission scheme, e.g. time sharing.


title: Remarks on a normal subgroup of GA_n

abstract:
  We show that the subgroup generated by locally finite polynomial
automorphisms of k^n is normal in GA_n. Also, some properties of normal
subgroups of GA_n containing all diagonal automorphisms are given.


title: Chemical evolution of the Milky Way and its Satellites

abstract:
  This paper contains the lectures I delivered during the 37th Saas-Fee
Advanced Course in March 2007. It reviews all the main ingredients necessary to
build galactic chemical evolution models with particular attention to the Milky
Way and the dwarf spheroidals of the Local Group. Both analytical and numerical
models are discussed. Model results are compared to observations in order to
infer constraints on stellar nucleosynthesis and on the formation and evolution
of galaxies.Particular attention is devoted to interpret abundance ratios in
galaxies with different star formation histories. Finally, the cosmic chemical
evolution is discussed


title:
Distributed Space Time Codes for the Amplify-and-Forward Multiple-Access
  Relay Channel

abstract:
  In this work, we present a construction of a family of space-time block codes
for a Multi-Access Amplify-and- Forward Relay channel with two users and a
single half-duplex relay. It is assumed that there is no Channel Side
Information at the transmitters and that they are not allowed to cooperate
together. Using the Diversity Multiplexing Tradeoff as a tool to evaluate the
performance, we prove that the proposed scheme is optimal in some sense.
Moreover, we provide numerical results which show that the new scheme
outperforms the orthogonal transmission scheme, e. g. time sharing and offers a
significant gain.


title: Multipolar expansion of orbital angular momentum modes

abstract:
  In this letter a general method for expanding paraxial beams into multipolar
electromagnetic fields is presented. This method is applied to the expansion of
paraxial modes with orbital angular momentum (OAM), showing how the paraxial
OAM is related to the general angular momentum of an electromagnetic wave. This
method can be extended to quasi-paraxial beams, i.e. highly focused laser
beams. Some applications to the control of electronic transitions in atoms are
discussed.


title: Differential modules on p-adic polyannuli

abstract:
  We consider variational properties of some numerical invariants, measuring
convergence of local horizontal sections, associated to differential modules on
polyannuli over a nonarchimedean field of characteristic zero. This extends
prior work in the one-dimensional case of Christol, Dwork, Robba, Young, et al.
Our results do not require positive residue characteristic; thus besides their
relevance to the study of Swan conductors for isocrystals, they are germane to
the formal classification of flat meromorphic connections on complex manifolds.


title:
Continuum limits of atomistic energies allowing smooth and sharp
  interfaces in 1D Elasticity

abstract:
  In this paper we present two atomistic models for the energy of a
one-dimensional elastic crystal. We assume that the macroscopic displacement
equals the microscopic one. The energy of the first model is given by a
two-body interaction potential, and we assume that the atoms follow a
continuous and piecewise smooth macroscopic (continuum) deformation. We
calculate the first terms of the Taylor expansion (with respect to the
parameter representing the interatomic distance) of the atomistic energy, and
obtain that the coefficients of that Taylor expansion represent, respectively,
an elastic energy, a sharp-interface energy, and a smooth-interface energy. The
second atomistic model is a variant of the first one, and its Taylor expansion
predicts, in addition, a new term that accounts for the repulsion force between
two sharp interfaces.


title: Neutrino Mass, Mixing, and Flavor Change

abstract:
  The physics of neutrino oscillation is summarized, and then the results of
oscillation experiments, including the most recent results, are discussed. The
possibility that neutrinos are their own antiparticles is examined. What we
have learned so far about the neutrinos is reviewed, and the questions to be
answered through future experiments are discussed.


title:
Be phenomenon in open clusters: Results from a survey of emission-line
  stars in young open clusters

abstract:
  Emission-line stars in young open clusters are identified to study their
properties, as a function of age, spectral type and their evolutionary state.
207 open star clusters were observed using slitless spectroscopy method and 157
emission stars were identified in 42 clusters. We have found 54 new
emission-line stars in 24 open clusters, out of which 19 clusters are found to
house emission stars for the first time. About 20% clusters harbour emission
stars. The fraction of clusters housing emission stars is maximum in both the
0--10 and 20--30 Myr age bin ($\sim$ 40% each) and in the other age bins, this
fraction ranges between 10% -- 25%, upto 80 Myr. We have used optical colour
magnitude diagram (CMD) along with Near-IR Colour-Colour diagram (NIR CCDm) to
classify the emission stars into Classical Be (CBe) stars and Herbig Be (HBe)
stars. Most of the emission stars in our survey belong to CBe class ($\sim$
92%) while a few are HBe stars ($\sim$ 6%) and HAe stars ($\sim$1%). The CBe
stars are located all along the MS in the optical CMDs of clusters of all ages,
which indicates that the Be phenomenon is unlikely due to core contraction near
the turn-off. Most of the clusters which contain emission stars are found in
Cygnus, Perseus & Monoceros region of the Galaxy, which are locations of active
star formation. The distribution of CBe stars as a function of spectral type
shows peaks at B1-B2 and B6-B7. Our results indicate there could be two
mechanisms responsible for the CBe phenomenon. Some are born CBe stars (fast
rotators), as indicated by their presence in clusters younger than 10 Myr. Some
stars evolve to CBe stars, as indicates by the enhancement in the fraction of
clusters with CBe stars in the 20-30 Myr age bin.


title: Search for a dark matter particle in high energy cosmic rays

abstract:
  Existing data hints that high energy cosmic ray experiments may offer the
most promissing shot at finding a dark matter particle. A search in the PeV
mass range is suggested, where the discovery of such a particle might help
explain the GZK cutoff violation data.


title: Status and Perspectives of Astroparticle Physics in Europe

abstract:
  Astroparticle physics has evolved as an interdisciplinary field at the
intersection of particle physics, astronomy and cosmology. Over the last two
decades, it has moved from infancy to technological maturity and is now
envisaging projects on the 100 Million Euro scale. This price tag requires
international coordination, cooperation and convergence to a few flagship
projects. The Roadmap Committee of ApPEC (Astroparticle Physics European
Coordination) has recently released a roadmap covering the next ten years. This
talk describes status and perspectives of astroparticle physics in Europe and
reports the recommendations of the Roadmap Committee.


title:
Use of stochastic sources for the lattice determination of light quark
  physics

abstract:
  In this paper we investigate the benefits of using Z(2)xZ(2) single timeslice
stochastic sources for the calculation of light quark physics on the lattice.
Meson 2-point correlators measured using sources stochastic in only spin and
those stochastic in both spin and colour indices are compared to point source
correlators on the unit gauge and on a 16^3 x 32 Domain Wall QCD ensemble. It
is found that the use of stochastic sources gives a considerable improvement in
statistics for the same computational cost. The neutral kaon mixing matrix
element B_K is also calculated on this ensemble with stochastic sources, but we
conclude that the stochastic method offers no significant advantage over the
traditional gauge-fixed wall source approach which already offers an exact
volume average. We also discuss the application to semileptonic form factors in
conjunction with partially twisted boundary conditions.


title:
A homage to E.C.G.Sudarshan: Superluminal objects and waves (An updated
  overview of the relevant experiments)

abstract:
  This writing has been prepared on the occasion of the 75th birthday of
E.C.George Sudarshan, who (besides the originator of the V-A theory for
weak-forces, of quantum optics --the quantum representation of coherent
light--, of dynamical maps for open quantum systems, of the Zeno effect, etc.)
was a pioneer, already in the sisties, also of the theory of the so-called
"tachyons".
  This paper wishes to be a homage to E.C.G.Sudarshan, in connection with the
last-mentioned pioneering work of his. After a brief theoretical introduction
(based on the standard postulates of Special Relativity, and therefore
extending it --or rather non-restricting it-- without any violations: for
example, without any violations of the so-called Einstein causality), the main
aim of this article is an updated presentation of the status-of-the-art of the
"superluminal" experiments. In particular, we devote such a review to the
phenomena met in tunneling through quantum (and classical) barriers [e.g.,
referring to the Genelalized Hartman Effect]; and in connection with the
"Localized (nondiffracting) Solutions" of the wave equantions [e.g., of Maxwell
equations]: especially of the "X-shaped" ones.
  The interested reader is provided with an extended Bibliography.


title:
Rationality of the moduli spaces of plane curves of sufficiently large
  degree

abstract:
  We prove that the moduli space of plane curves of degree d is rational for
all sufficiently large d.


title: Is Science Nearing Its Limits ? Summarizing Dialogue

abstract:
  In 2007 an international conference engaged a reflection on the present
conditions for sciences and scientific practice, to initiate a dialogue between
science, philosophy, epistemology and sociology. Starting from many examples
taken from the history of sciences and the present status of astrophysics,
cosmology and fundamental physics, I analyze various issues such as the
possible limits of theoretical and technological advances, the paradox of
non-verifiability in string theory, incompleteness, the role of imagination in
scientific research along with educational aspects, the epistemological value
of the Ockham's razor principle for constraining theories, and our undersanding
of man's place in Creation.


title: Generating Generalized $G_{D-2}$ solutions

abstract:
  We show how one can systematically construct vacuum solutions to Einstein
field equations with $D-2$ commuting Killing vectors in $D>4$ dimensions. The
construction uses Einstein-scalar field seed solutions in 4 dimensions and is
performed both for the case when all the Killing directions are spacelike, as
well as when one of the Killing vectors is timelike. The later case corresponds
to generalizations of stationary axially symmetric solutions to higher
dimensions. Some examples representing generalizations of known higher
dimensional stationary solutions are discussed in terms of their rod structure
and horizon locations and deformations.


title:
Comment on ``Measurement of the $^3$He mass diffusion coefficient in
  superfluid $^4$He over the 0.45--0.95 K temperature range

abstract:
  The role of 3He-3He collisions in our diffusion experiment is addressed and
shown to not be relevant to the measurement of 3He diffusion against phonons in
superfluid helium.


title: Predictability of the large relaxations in a cellular automaton model

abstract:
  A simple one-dimensional cellular automaton model with threshold dynamics is
introduced. The cumulative distribution of the size of the relaxations is
analytically computed and behaves as a power law with an exponent equal to -1.
This coincides with the phenomenological Gutenberg-Richter behavior observed in
Seismology for the cumulative statistics of earthquakes at the regional or
global scale. The key point of the model is the zero-load state of the system
after the occurrence of any relaxation, no matter what its size. This leads to
an equipartition of probability between all possible load configurations in the
system during the successive loading cycles. Each cycle ends with the
occurrence of the greatest -or characteristic- relaxation in the system. The
duration of the cycles in the model is statistically distributed with a
coefficient of variation ranging from 0.5 to 1. The predictability of the
characteristic relaxations is evaluated by means of error diagrams. This model
illustrates the value of taking into account the refractory periods to obtain a
considerable gain in the quality of the predictions.


title: On an identity of Ky Fan

abstract:
  We give several applications of an identity for sums of weakly stationary
sequences due to Ky Fan.


title:
The rationality of the moduli space of curves of genus 3 after P.
  Katsylo

abstract:
  This article is a survey of P. Katsylo's proof that the moduli space of
smooth projective complex curves of genus 3 is rational. We hope to make the
argument more comprehensible and transparent by emphasizing the underlying
geometry in the proof and its key structural features.


title:
Stationary Oscillations in a Damped Wave Equation from Isospectral
  Bessel Functions

abstract:
  Using the isospectral partners of the Bessel functions derived by Reyes et
al., we find, on one hand, that these functions show non-typical supersymmetric
(SUSY) behavior and, on the other, that the isospectral partner of the
classical wave equation is equivalent to that of a damped system whose
oscillations do not vanish in time, but show a non-harmonic shape.


title:
Time- and Spacelike Nucleon Electromagnetic Form Factors beyond
  Relativistic Constituent Quark Models

abstract:
  For the first time, a phenomenological analysis of the experimental
electromagnetic form factors of the nucleon, both in the timelike and spacelike
regions, is performed by taking into account the effects of nonvalence
components in the nucleon state, within a light-front framework. Our model,
based on suitable Ansatzes for the nucleon Bethe-Salpeter amplitude and a
microscopic version of the well-known Vector Meson Dominance model, has only
four free parameters (determined by the spacelike data with $\chi^2/datum \sim
1.7$), and yields a nice description of the experimental electromagnetic form
factors in the physical region in the range $-30 (GeV/c)^2 < q^2 < 20
(GeV/c)^2$, except for the neutron one in the timelike region. Valuable
information can be gained in the timelike region on possible missing Vector
Mesons around $q^2 \sim 4.5 (GeV/c)^2$ and $q^2 \sim 8.0 (GeV/c)^2$


title:
Optical Weights and Waterfalls in Doped Charge Transfer Insulators: an
  LDA+DMFTStudy of LSCO

abstract:
  We use the Local Density Approximation in combination with the Dynamical Mean
Field Theory to investigate intermediate energy properties of the copper
oxides. We identify coherent and incoherent spectral features that results from
doping a charge transfer insulator, namely quasiparticles, Zhang-Rice singlet
band, and the upper and lower Hubbard bands. Angle resolving these features, we
identify a \emphasize{waterfall} like feature, between the quasiparticle part
and the incoherent part of the Zhang-Rice band. We investigate the assymetry
between particle and hole doping. On the hole doped side, there is a very rapid
transfer of spectral weight upon doping in the one particle spectra. The
optical spectral weight increases superlinearly on the hole doped side in
agreement with experiments.


title: Geometry of whips and chains

abstract:
  We study the geometry of the inextensible string (the whip) and its discrete
approximation (the chain). In the absence of gravity, both motions represent
geodesic motions on certain manifolds. We show how the motion of the chain
converges to that of a whip, and how the curvature of the chain's configuration
space converges to that of the whip's configuration space. Finally we speculate
on the analogous approximation of an incompressible fluid by a discrete system.


title:
Time-dependent current-density-functional theory of spin-charge
  separation and spin drag in one-dimensional ultracold Fermi gases

abstract:
  Motivated by the large interest in the non-equilibrium dynamics of
low-dimensional quantum many-body systems, we present a fully-microscopic
theoretical and numerical study of the "charge" and "spin" dynamics in a
one-dimensional ultracold Fermi gas following a quench. Our approach, which is
based on time-dependent current-density-functional theory, is applicable well
beyond the linear-response regime and produces both spin-charge separation and
spin-drag-induced broadening of the spin packets.


title:
On properties of the space of quantum states and their application to
  construction of entanglement monotones

abstract:
  We consider two properties of the set of quantum states as a convex
topological space and some their implications concerning the notions of a
convex hull and of a convex roof of a function defined on a subset of quantum
states.
  By using these results we analyze two infinite-dimensional versions (discrete
and continuous) of the convex roof construction of entanglement monotones,
which is widely used in finite dimensions. It is shown that the discrete
version may be 'false' in the sense that the resulting functions may not
possess the main property of entanglement monotones while the continuous
version can be considered as a 'true' generalized convex roof construction. We
give several examples of entanglement monotones produced by this construction.
In particular, we consider an infinite-dimensional generalization of the notion
of Entanglement of Formation and study its properties.


title: Unraveling the "Pressure-Effect" in Nucleation

abstract:
  The influence of the pressure of a chemically inert carrier-gas on the
nucleation rate is one of the biggest puzzles in the research of gas-liquid
nucleation. Different experiments can show a positive effect, a negative
effect, or no effect at all. The same experiment may show both trends for the
same substance depending on temperature, or for different substances at the
same temperature. We show how this ambiguous effect naturally arises from the
competition of two contributions: nonisothermal effects and pressure-volume
work. Our model clarifies seemingly contradictory experimental results and
quantifies the variation of the nucleation ability of a substance in the
presence of an ambient gas. Our findings are corroborated by results from
molecular dynamics simulation and might have important implications since
nucleation in experiments, technical applications, and nature practically
always occurs in the presence of an ambient gas.


title:
The evolution of the galaxy Red Sequence in simulated clusters and
  groups

abstract:
  N-body + hydrodynamical simulations of the formation and evolution of galaxy
groups and clusters in a LambdaCDM cosmology are used in order to follow the
building-up of the colour-magnitude relation in two clusters and in 12 groups.
We have found that galaxies, starting from the more massive, move to the Red
Sequence (RS) as they get aged over times and eventually set upon a ``dead
sequence'' (DS) once they have stopped their bulk star formation activity.
Fainter galaxies keep having significant star formation out to very recent
epochs and lie broader around the RS.
  Environment plays a role as galaxies in groups and cluster outskirts hold
star formation activity longer than the central cluster regions. However
galaxies experiencing infall from the outskirts to the central parts keep star
formation on until they settle on to the DS of the core galaxies. Merging
contributes to mass assembly until z~1, after which major events only involve
the brightest cluster galaxies.
  The emerging scenario is that the evolution of the colour-magnitude
properties of galaxies within the hierarchical framework is mainly driven by
star formation activity during dark matter halos assembly. Galaxies
progressively quenching their star formation settle to a very sharp ``red and
dead'' sequence, which turns out to be universal, its slope and scatter being
almost independent of the redshift (since at least z~1.5) and environment.
  Differently from the DS, the operatively defined RS evolves more evidently
with z, the epoch when it changes its slope being closely corresponding to that
at which the passive galaxies population takes over the star forming one: this
goes from z~1 in clusters down to 0.4 in normal groups.


title:
Pre-main sequence stars, emission stars and recent star formation in the
  Cygnus Region

abstract:
  The recent star formation history in the Cygnus region is studied using 5
clusters (IC 4996, NGC 6910, Berkeley 87, Biurakan 2 and Berkeley 86). The
optical data from the literature are combined with the 2MASS data to identify
the pre-main sequence (pre-MS) stars as stars with near IR excess. We
identified 93 pre-MS stars and 9 stars with H$_\alpha$ emission spectra. The
identified pre-MS stars are used to estimate the turn-on age of the clusters.
The duration of star formation was estimated as the difference between the
turn-on and the turn-off age. We find that, NGC 6910 and IC 4996 have been
forming stars continuously for the last 6 -- 7 Myr, Berkeley 86 and Biurakan 2
for 5 Myr and Berkeley 87 for the last 2 Myr. This indicates that the Cygnus
region has been actively forming stars for the last 7 Myr, depending on the
location. 9 emission line stars were identified in 4 clusters, using slit-less
spectra (Be 87 - 4 stars; Be 86 - 2 stars, NGC 6910 - 2 stars and IC 4996 - 1
star). The individual spectra were obtained and analysed to estimate stellar as
well as disk properties. All the emission stars are in the MS, well below the
turn-off, in the core hydrogen burning phase. These stars are likely to be
Classical Be (CBe) stars. Thus CBe phenomenon can be found in very young MS
stars which are just a few (2 -- 7) Myrs old. This is an indication that CBe
phenomenon need not be an evolutionary effect.