title: Quadratic maps between modules

abstract:
  We introduce a notion of $R$-quadratic maps between modules over a
commutative ring $R$ which generalizes several classical notions arising in
linear algebra and group theory. On a given module $M$ such maps are
represented by $R$-linear maps on a certain module $P^2_R(M)$. The structure of
this module is described in term of the symmetric tensor square $Sym^2_R(M)$,
the degree 2 component $\Gamma^2_R(M)$ of the divided power algebra over $M$,
and the ideal $I_2$ of $R$ generated by the elements $r^2-r$, $r\in R$. The
latter is shown to represent quadratic derivations on $R$ which arise in the
theory of modules over square rings. This allows to extend the classical notion
of nilpotent $R$-group of class 2 with coefficients in a 2-binomial ring $R$ to
any ring $R$. We provide a functorial presentation of $I_2$ and several exact
sequences embedding the modules $P^2_R(M)$ and $\Gamma^2_R(M)$.


title: Light Logics and the Call-by-Value Lambda Calculus

abstract:
  The so-called light logics have been introduced as logical systems enjoying
quite remarkable normalization properties. Designing a type assignment system
for pure lambda calculus from these logics, however, is problematic. In this
paper we show that shifting from usual call-by-name to call-by-value lambda
calculus allows regaining strong connections with the underlying logic. This
will be done in the context of Elementary Affine Logic (EAL), designing a type
system in natural deduction style assigning EAL formulae to lambda terms.


title:
Twenty-five years of multifractals in fully developed turbulence: a
  tribute to Giovanni Paladin

abstract:
  The paper {\it On the multifractal nature of fully developed turbulence and
chaotic systems}, by R. Benzi {\it et al.} published in this journal in 1984
(vol {\bf 17}, page 3521) has been a starting point of many investigations on
the different faces of selfsimilarity and intermittency in turbulent phenomena.
  Since then, the multifractal model has become a useful tool for the study of
small scale turbulence, in particular for detailed predictions of different
Eulerian and Lagrangian statistical properties. In the occasion of the 50-th
birthday of our unforgettable friend and colleague Giovanni Paladin
(1958-1996), we review here the basic concepts and some applications of the
multifractal model for turbulence.


title: Dumbbell diffusion in a spatially periodic potential

abstract:
  We present a numerical investigation of the Brownian motion and diffusion of
a dumbbell in a two-dimensional periodic potential. Its dynamics is described
by a Langevin model including the hydrodynamic interaction. With increasing
values of the amplitude of the potential we find along the modulated spatial
directions a reduction of the diffusion constant and of the impact of the
hydrodynamic interaction. For modulation amplitudes of the potential in the
range of the thermal energy the dumbbell diffusion exhibits a pronounced local
maximum at a wavelength of about 3/2 of the dumbbell extension. This is
especially emphasized for stiff springs connecting the two beads.


title:
An embedded-atom method model for liquid Co, Nb, Zr and supercooled
  binary alloys

abstract:
  The parameters of many-body potentials for Co, Nb and Zr metals, based on the
embedded-atom method, have been systematically derived. The analytical
potential scheme allows us to reproduce correctly the cohesive energies and
structural properties of the pure metals and selected alloys making use of a
small set of parameters. With a pair potential going smoothly to zero for a
sufficient cutoff radius, radial partial and bond angular distribution
functions for Co, Nb, Zr and alloys are computed using molecular dynamics
simulations that ensure good quantitative agreement with the available
experimental data up to the melting point. Atomic short range order is analysed
in the light of consecutive Gaussian function decomposition and
Honeycutt-Andersen indices.


title: Dense Error Correction via L1-Minimization

abstract:
  This paper studies the problem of recovering a non-negative sparse signal $\x
\in \Re^n$ from highly corrupted linear measurements $\y = A\x + \e \in \Re^m$,
where $\e$ is an unknown error vector whose nonzero entries may be unbounded.
Motivated by an observation from face recognition in computer vision, this
paper proves that for highly correlated (and possibly overcomplete)
dictionaries $A$, any non-negative, sufficiently sparse signal $\x$ can be
recovered by solving an $\ell^1$-minimization problem: $\min \|\x\|_1 +
\|\e\|_1 \quad {subject to} \quad \y = A\x + \e.$ More precisely, if the
fraction $\rho$ of errors is bounded away from one and the support of $\x$
grows sublinearly in the dimension $m$ of the observation, then as $m$ goes to
infinity, the above $\ell^1$-minimization succeeds for all signals $\x$ and
almost all sign-and-support patterns of $\e$. This result suggests that
accurate recovery of sparse signals is possible and computationally feasible
even with nearly 100% of the observations corrupted. The proof relies on a
careful characterization of the faces of a convex polytope spanned together by
the standard crosspolytope and a set of iid Gaussian vectors with nonzero mean
and small variance, which we call the ``cross-and-bouquet'' model. Simulations
and experimental results corroborate the findings, and suggest extensions to
the result.


title: Low-momentum effective interaction in the three-dimensional approach

abstract:
  The formulation of the low-momentum effective interaction in the model space
Lee-Suzuki and the renormalization group methods is implemented in the
three-dimensional approach. In this approach the low-momentum effective
interaction V_{low k} has been formulated as a function of the magnitude of
momentum vectors and the angle between them. As an application the spin-isospin
independent Malfliet-Tjon potential has been used into the model space
Lee-Suzuki method and it has been shown that the low-momentum effective
interaction V_{low k} reproduces the same two-body observables obtained by the
bare potential V_{NN}.


title: The absorber hypothesis of electrodynamics

abstract:
  We test the absorber hypothesis of the action-at-a-distance electrodynamics
for globally-bounded solutions of a finite-particle universe. We find that the
absorber hypothesis forbids globally-bounded motions for a universe containing
only two charged particles, otherwise the condition alone does not forbid
globally-bounded motions. We discuss the implication of our results for the
various forms of electrodynamics of point charges.


title:
Role of polarization in probing anomalous gauge interactions of the
  Higgs boson

abstract:
  We explore the use of polarized $e^+/e^-$ beams and/or the information on
final state decay lepton polarizations in probing the interaction of the Higgs
boson with a pair of vector bosons. A model independent analysis of the process
$e^+ e^- \to f \bar f H$, where $f$ is any light fermion, is carried out
through the construction of observables having identical properties under the
discrete symmetry transformations as different individual anomalous
interactions. This allows us to probe an individual anomalous term independent
of the others. We find that initial state beam polarization can significantly
improve the sensitivity to CP-odd couplings of the $Z$ boson with the Higgs
boson ($ZZH$). Moreover, an ability to isolate events with a particular $\tau$
helicity, with even 40% efficiency, can improve sensitivities to certain $ZZH$
couplings by as much as a factor of 3. In addition, the contamination from the
$ZZH$ vertex contributions present in the measurement of the trilinear
Higgs-$W$ ($WWH$) couplings can be reduced to a great extent by employing
polarised beams. The effects of initial state radiation (ISR) and
beamstrahlung, which can be relevant for higher values of the beam energy are
also included in the analysis.


title:
Surface anisotropy broadening of the energy barrier distribution in
  magnetic nanoparticles

abstract:
  The effect of surface anisotropy on the distribution of energy barriers in
magnetic fine particles of nanometer size is discussed within the framework of
the $T\ln(t/\tau_0)$ scaling approach. The comparison between the distributions
of the anisotropy energy of the particle cores, calculated by multiplying the
volume distribution by the core anisotropy, and of the total anisotropy energy,
deduced by deriving the master curve of the magnetic relaxation with respect to
the scaling variable $T\ln(t/\tau_0)$, enables the determination of the surface
anisotropy as a function of the particle size. We show that the contribution of
the particle surface to the total anisotropy energy can be well described by a
size--independent value of the surface energy per unit area which permits the
superimposition of the distributions corresponding to the particle core and
effective anisotropy energies. The method is applied to a ferrofluid composed
of non-interacting Fe$_{3-x}$O$_{4}$ particles of 4.9 nm in average size and
$x$ about 0.07. Even though the size distribution is quite narrow in this
system, a relatively small value of the effective surface anisotropy constant
$K_{s}=2.9\times 10^{-2}$ erg cm$^{-2}$ gives rise to a dramatic broadening of
the total energy distribution. The reliability of the average value of the
effective anisotropy constant, deduced from magnetic relaxation data, is
verified by comparing it to that obtained from the analysis of the shift of the
ac susceptibility peaks as a function of the frequency.


title: Heatons induced by attosecond laser pulses

abstract:
  In this paper the dynamics of the interaction of attosecond laser pulses with
matter is investigated. It will be shown that the master equation: modified
Klein-Gordon equation describes the propagation of the heatons. Heatons are the
thermal wave packets. When the duration of the laser pulses is of the order of
attosecond the heaton thermal wave packets are nondispersive objects. For
infinite time the heatons are damped with damping factor of the order of
relaxation time for thermal processes.


title:
The structure of the nilpotent cone, the Kazhdan-Lusztig map and
  algebraic group analogues of the Slodowy slices

abstract:
  We define algebraic group analogues of the Slodowy transversal slices to
adjoint orbits in a complex semisimple Lie algebra g. The new slices are
transversal to the conjugacy classes in an algebraic group G with Lie algebra
g. These slices are associated to (the conjugacy classes of) elements s of the
Weyl group W of g. For such slices we prove an analogue of the Kostant
cross-section theorem for the action of a unipotent group.


title:
VLT detection of a red supergiant progenitor of the type IIP supernova
  2008bk

abstract:
  We report the identification of a source coincident with the position of the
nearby type II-P supernova (SN) 2008bk in high quality optical and
near-infrared pre-explosion images from the ESO Very Large Telescope (VLT). The
SN position in the optical and near-infrared pre-explosion images is identified
to within about +-70 and +-40 mas, respectively, using post-explosion Ks-band
images obtained with the NAOS CONICA adaptive optics system on the VLT. The
pre-explosion source detected in four different bands is precisely coincident
with SN 2008bk and is consistent with being dominated by a single point source.
We determine the nature of the point source using the STARS stellar
evolutionary models and find that its colours and luminosity are consistent
with the source being a red supergiant progenitor of SN 2008bk with an initial
mass of 8.5 +- 1.0 Msun.


title:
Combined Raman scattering and ab initio investigation of
  pressure-induced structural phase transitions in the scintillator ZnWO4

abstract:
  Room-temperature Raman scattering was measured in ZnWO4 up to 45 GPa. We
report the pressure dependence of all the Raman-active phonons of the
low-pressure wolframite phase. As pressure increases new Raman peaks appear at
30.6 GPa due to the onset of a reversible structural phase transition to a
distorted monoclinic b-fergusonite-type phase. The low- and high-pressure
phases coexist from 30.6 GPa to 36.5 GPa. In addition to the Raman measurements
we also report ab initio total-energy and lattice-dynamics calculations for the
two phases. These calculations helped us to determine the crystalline structure
of the high-pressure phase and to assign the observed Raman modes in both the
wolframite and b-fergusonite phases. Based upon the ab initio calculations we
propose the occurrence of a second phase transition at 57.6 GPa from the
b-fergusonite phase to an orthorhombic Cmca phase. The pressure evolution of
the lattice parameters and the atomic positions of wolframite ZnWO4 are also
theoretically calculated and an equation of state reported.


title: Subspace Techniques for Radio-Astronomical Data Enhancement

abstract:
  Radio astronomical observations have very poor signal to noise ratios, unlike
in other disciplines. On the other hand, it is possible to observe the object
of interest for long time intervals as well as using a wider bandwidth.
Traditionally, by averaging in time and in frequency, it has been possible to
improve the signal to noise ratio of astronomical observations to improve the
dynamic range. This is possible due to the inherent assumption that the object
of interest in the sky is invariant over time and the frequency range of
observation. However, in reality this assumption does not hold, due to
intrinsic variation of the sky as well as due to errors generated by the
instrument. In this paper, we shall discuss an alternative to averaging of
images, without ignoring subtle changes in the observed data over time and
frequency, using subspace decomposition. By separation of data to signal and
noise subspaces, not only would this improve the quality of the data, but also
enable us to detect faint artifacts due to calibration errors, interference
etc.


title:
Velocity dispersions in a cluster of stars: How fast could Usain Bolt
  have run?

abstract:
  Since that very memorable day at the Beijing 2008 Olympics, a big question on
every sports commentator's mind has been "What would the 100 meter dash world
record have been, had Usain Bolt not celebrated at the end of his race?" Glen
Mills, Bolt's coach suggested at a recent press conference that the time could
have been 9.52 seconds or better. We revisit this question by measuring Bolt's
position as a function of time using footage of the run, and then extrapolate
into the last two seconds based on two different assumptions. First, we
conservatively assume that Bolt could have maintained Richard Thompson's, the
runner-up, acceleration during the end of the race. Second, based on the race
development prior to the celebration, we assume that he could also have kept an
acceleration of 0.5 m/s^2 higher than Thompson. In these two cases, we find
that the new world record would have been 9.61 +/- 0.04 and 9.55 +/- 0.04
seconds, respectively, where the uncertainties denote 95% statistical errors.


title: An analytical formulation for phi^4 field-potential dynamics

abstract:
  An analytical model for adding a space dependent potential to the phi^4 field
is presented, by constructing a collective coordinate for solitary solution of
this model. Interaction of the $\phi^{4}$ field with a delta function potential
barrier and also delta function potential well is investigated. Most of the
characters of the interaction are derived analytically while they are
calculated by other models numerically. We will find that the behaviour of the
solitary solution is like a point particle 'living' under the influence of a
complicated potential which is a function of the field initial conditions and
the potential parameters.


title: Traveling spatially periodic forcing of phase separation

abstract:
  We present a theoretical analysis of phase separation in the presence of a
spatially periodic forcing of wavenumber q traveling with a velocity v. By an
analytical and numerical study of a suitably generalized 2d-Cahn-Hilliard model
we find as a function of the forcing amplitude and the velocity three different
regimes of phase separation. For a sufficiently large forcing amplitude a
spatially periodic phase separation of the forcing wavenumber takes place,
which is dragged by the forcing with some phase delay. These locked solutions
are only stable in a subrange of their existence and beyond their existence
range the solutions are dragged irregularly during the initial transient period
and otherwise rather regular. In the range of unstable locked solutions a
coarsening dynamics similar to the unforced case takes place. For small and
large values of the forcing wavenumber analytical approximations of the
nonlinear solutions as well as for the range of existence and stability have
been derived.


title:
Axial anomaly in quantum electro- and chromodynamics and the structure
  of the vacuum in quantum chromodynamics

abstract:
  In this report, I discuss the current state of the problem of the axial
anomaly in quantum electrodynamics (QED) and quantum chromodynamics (QCD) and
how the axial anomaly is related to the structure of the vacuum in QCD. In QCD,
the vacuum average of the axial anomaly is proportional to a new quantum number
n, the winding number. The axial anomaly condition implies that there are zero
modes of the Dirac equation for a massless quark and that there is spontaneous
breaking of chiral symmetry in QCD, which leads to the formation of a quark
condensate. The axial anomaly can be represented in the form of a sum rule the
structure function in the dispersion representation of the axial -- vector --
vector (AVV) vertex. On the basis of this sum rule, it is calculated the width
of the \pi^0\to 2\gamma decay with an accuracy of 1.5%. It is demonstrated,
that 't Hooft conjecture -- the singularities of the amplitudes calculated in
perturbative QCD on quark-gluon basis should reproduce themselves in
calculations on the hadrons basis -- is not fulfilled generally.


title:
Spatial distribution of the emission intensity in a photonic crystal:
  Self-interference of Bloch eigenwaves

abstract:
  The analysis of an angular distribution of the emission intensity of a
two-level atom (dipole) in a photonic crystal reveals an enhancement of the
emission rate in some observation directions. Such an enhancement is the result
of the bunching of many Bloch eigenwaves with different wave vectors in the
same direction due to the crystal anisotropy. If a spatial distribution of the
emission intensity is considered, the interference of these eigenwaves should
be taken into account. In this paper, the far-field emission pattern of a
two-level atom is discussed in the framework of the asymptotic analysis the
classical macroscopic Green function. Numerical example is given for a
two-dimensional square lattice of air holes in polymer. The relevance of
results for experimental observation is discussed.


title: The modulation of SiO maser polarization by Jovian planets

abstract:
  Searching for planets in the atmosphere of AGB stars is difficult, due to
confusion with the stellar wind and pulsations. The aim here is to provide a
complementary strategy for planet search in such a dense environment. The
polarization properties of SiO masers, especially their circular polarization,
are, under certain conditions, good tracers for rapid magnetospheric events. A
Jovian planet with a magnetosphere whose dipole axis is misaligned with its
rotation axis, naturally provides such conditions. Here I present several
models showing that the polarization will be periodically modulated.
Single-dish monitoring with a sufficiently dense time sampling and a carefully
calibrated polarimeter, in combination with VLBI observations, are suited to
detect and locate a periodic modulation of the circular maser polarization due
to a precessing Jovian magnetosphere. The phenomenon will be rare, because a
favourable arrangement of maser and magnetosphere is needed, otherwise the
polarization may be below the detection threshold, especially if the maser is
unsaturated. Linear polarization, though exhibiting a qualitatively similar
modulation, is likely to suffer more from confusion due to beam dilution, even
in VLBI observations.


title:
A necessary and sufficient condition for the invertibility of adapted
  perturbations of identity on the Wiener space

abstract:
  Let $(W,H,\mu)$ be the classical Wiener space, assume that $U=I_W+u$ is an
adapted perturbation of identity satisfying the Girsanov identity. Then, $U$ is
invertible if and only if the kinetic energy of $u$ is equal to the relative
entropy of the measure induced with the action of $U$ on the Wiener measure
$\mu$, in other words $U$ is invertible if and only if $$ \half
\int_W|u|_H^2d\mu=\int_W \frac{dU\mu}{d\mu}\log\frac{dU\mu}{d\mu}d\mu . $$


title: Colliding Message Pairs for 23 and 24-step SHA-512

abstract:
  Recently, Indesteege et al. [1] had described attacks against 23 and 24-step
SHA-512 at SAC '08. Their attacks are based on the differential path by Nikolic
and Biryukov [2]. The reported complexities are $2^{44.9}$ and $2^{53}$ calls
to the respective step reduced SHA-512 hash function. They provided colliding
message pairs for 23-step SHA-512 but did not provide a colliding message pair
for 24-step SHA-512. In this note we provide a colliding message pair for
23-step SHA-512 and the first colliding message pair for 24-step SHA-512. Our
attacks use the differential path first described by Sanadhya and Sarkar at
ACISP '08 [3]. The complexities of our attacks are $2^{16.5}$ and $2^{34.5}$
calls to the respective step reduced SHA-512 hash function. Complete details of
the attacks will be provided in an extended version of this note.


title:
Graphene in a Strong Magnetic Field: Massless Dirac Particles vs.
  Skyrmions

abstract:
  We discuss models for massless Dirac fermions being subject to a
perpendicular magnetic field in spherical geometry. These models are analogues
of Haldane`s spherical construction for massful charge carriers. The single
particle states constructed here are easily implemented in existing numerical
code for many-body problems in conventional quantum Hall systems. Moreover, the
many-body states of fully filled sublevels in the subspace of lowest Landau
level index are skyrmions with respect to the layer spin.


title: Dynamical tomography of gravitationally bound systems

abstract:
  We study the inverse problem of deducing the dynamical characteristics (such
as the potential field) of large systems from kinematic observations. We show
that, for a class of steady-state systems, the solution is unique even with
fragmentary data, dark matter, or selection (bias) functions. Using spherically
symmetric models for simulations, we investigate solution convergence and the
roles of data noise and regularization in the inverse problem. We also present
a method, analogous to tomography, for comparing the observed data with a model
probability distribution such that the latter can be determined.


title: Parametrization of the QCD coupling in Hard and Regge processes

abstract:
  We examine the parametrization of the QCD coupling in the Bethe-Salpeter
equations for the hard and Regge processes and determine the argument of
alpha_s of the factorized gluon. Our analysis shows that for the hard processes
alpha_s = alpha_s(k^2_T/(1- beta)) where k^2_T and beta are the longitudinal
and transverse moment of the soft parton. On the other hand, in the Regge
processes alpha_s = alpha_s(k^2_T}/beta). We have also shown that the
well-known parametrization alpha_s = alpha_s(k^2_T) in the DGLAP equations
stands only if the lowest integration limit, mu^2, over k^2_T (the starting
point of the Q^2 -evolution) obeys the relation mu >> Lambda_{QCD} exp
{(\pi/2)}, otherwise the coupling should be replaced by the more complicated
expression.


title:
Gamma-ray polarization constraints on Planck scale violations of special
  relativity

abstract:
  Using recent polarimetric observations of the Crab Nebula in the hard X-ray
band by INTEGRAL, we show that the absence of vacuum birefringence effects
constrains O(E/M) Lorentz violation in QED to the level |\xi| < 9x10^{-10} at
three sigma CL, tightening by more than three orders of magnitude previous
constraints. We show that planned X-ray polarimeters have the potential the
potential to probe |\xi|~ 10^{-16} by detecting polarization in active galaxies
at red-shift ~1.


title: Rotational stabilization and destabilization of an optical cavity

abstract:
  We investigate the effects of rotation about the axis of an astigmatic
two-mirror cavity on its optical properties. This simple geometry is the first
example of an optical system that can be destabilized and, more surprisingly,
stabilized by rotation. As such, it has some similarity with both the Paul trap
and the gyroscope. We illustrate the effects of rotational (de)stabilization of
a cavity in terms of the spatial structure and orbital angular momentum of its
modes.


title: $B \to D^{(*)}$ Form Factors from QCD Light-Cone Sum Rules

abstract:
  We derive new QCD sum rules for $B\to D$ and $B\to D^*$ form factors. The
underlying correlation functions are expanded near the light-cone in terms of
$B$-meson distribution amplitudes defined in HQET, whereas the $c$-quark mass
is kept finite. The leading-order contributions of two- and three-particle
distribution amplitudes are taken into account. From the resulting light-cone
sum rules we calculate all $B\to \Dst $ form factors in the region of small
momentum transfer (maximal recoil). In the infinite heavy-quark mass limit the
sum rules reduce to a single expression for the Isgur-Wise function. We compare
our predictions with the form factors extracted from experimental $B\to \Dst l
\nu_l$ decay rates fitted to dispersive parameterizations.


title: Ambiguities in the HBT approach to determine the interaction regions

abstract:
  The necessary and sufficient condition for a quantity to be measurable by the
HBT method is given and discussed.


title: The Semisimplicity Conjecture for A-Motives

abstract:
  We prove the semisimplicity conjecture for A-motives over finitely generated
fields K. This conjecture states that the rational Tate modules V_p(M) of a
semisimple A-motive M are semisimple as representations of the absolute Galois
group of K. This theorem is in analogy with known results for abelian varieties
and Drinfeld modules, and has been sketched previously by Akio Tamagawa.
  We deduce two consequences of the theorem for the algebraic monodromy groups
G_p(M) associated to an A-motive M by Tannakian duality. The first requires no
semisimplicity condition on M and states that G_p(M) may be identified
naturally with the Zariski closure of the image of the absolute Galois group of
K in the automorphism group of V_p(M). The second states that the connected
component of G_p(M) is reductive if M is semisimple and has a separable
endomorphism algebra.


title: Derived categories of Fano threefolds

abstract:
  We consider the structure of the derived categories of coherent sheaves on
Fano threefolds with Picard number 1 and describe a strange relation between
derived categories of different threefolds. In the Appendix we discuss how the
ring of algebraic cycles of a smooth projective variety is related to the
Grothendieck group of its derived category.


title: A model for trimaximal lepton mixing

abstract:
  We consider trimaximal lepton mixing, defined by |U_{alpha 2}|^2 = 1/3 for
all alpha = e, mu, tau. This corresponds to a two-parameter lepton mixing
matrix U. We present a model for the lepton sector in which trimaximal mixing
is enforced by softly broken discrete symmetries; one version of the model is
based on the group Delta(27). A salient feature of our model is that no vacuum
alignment is required.


title: Beam loading in the nonlinear regime of plasma-based acceleration

abstract:
  A theory that describes how to load negative charge into a nonlinear,
three-dimensional plasma wakefield is presented. In this regime, a laser or an
electron beam blows out the plasma electrons and creates a nearly spherical ion
channel, which is modified by the presence of the beam load. Analytical
solutions for the fields and the shape of the ion channel are derived. It is
shown that very high beam-loading efficiency can be achieved, while the energy
spread of the bunch is conserved. The theoretical results are verified with the
Particle-In-Cell code OSIRIS.


title: Smart spatial incentives for market-based conservation

abstract:
  Market-based instruments such as payments, auctions or tradable permits have
been proposed as flexible and cost-effective instruments for biodiversity
conservation on private lands. Trading the service of conservation requires one
to define a metric that determines the extent to which a conserved site adds to
the regional conservation objective. Yet, while markets for conservation are
widely discussed and increasingly applied, little research has been conducted
on explicitly accounting for spatial ecological processes in the trading. In
this paper, we use a coupled ecological economic simulation model to examine
how spatial connectivity may be considered in the financial incentives created
by a market-based conservation scheme. Land use decisions, driven by changing
conservation costs and the conservation market, are simulated by an agent-based
model of land users. On top of that, a metapopulation model evaluates the
conservational success of the market. We find that optimal spatial incentives
for agents correlate with species characteristics such as the dispersal
distance, but they also depend on the spatio-temporal distribution of
conservation costs. We conclude that a combined analysis of ecological and
socio-economic conditions should be applied when designing market instruments
to protect biodiversity.


title:
Visible and near infra-red up-conversion in Tm3+/Yb3+ co-doped silica
  fibres under 980 nm excitation

abstract:
  The spectroscopic properties of Tm3+/Yb3+ co-doped silica fibers under
excitation at 980 nm are reported. Three distinct up-conversion fluorescence
bands were observed in the visible to near infra-red regions. The blue and red
fluorescence bands at 475 and 650 nm, respectively, were found to originate
from the 1G4 level of Tm3+. A three step up-conversion process was established
as the populating mechanism for these fluorescence bands. The fluorescence band
at 800 nm was found to originate from two possible transitions in Tm3+; one
being the transition from the 3H4 to 3H6 manifold which was found to dominate
at low pump powers; the other being the transition from the 1G4 to 3H6 level
which dominates at higher pump powers. The fluorescence lifetime of the 3H4 and
3F4 levels of Tm3+ and 2F5/2 level of Yb3+ were studied as a function of Yb3+
concentration, with no significant energy back transfer from Tm3+ to Yb3+
observed.


title: Entropy of semiclassical measures in dimension 2

abstract:
  We study the asymptotic properties of eigenfunctions of the Laplacian in the
case of a compact Riemannian surface of Anosov type. We show that the
Kolmogorov-Sinai entropy of a semiclassical measure for the geodesic flow is
bounded from below by half of the Ruelle upper bound


title:
L'Algebre Tropicale Comme Algebre De la Caracteristique 1 : Polynomes
  Rationnels Et Fonctions Polynomiales

abstract:
  We continue, in this second article, the study of the the algebraic tools
which play a role in tropical algebra. We especially examine here the
polynomial algebras over idempotent semi-fields. this work is motivated by the
development of tropical geometry which appears to be the algebraic geometry of
tropical algebra. In fact, the most interesting object is the image of a
polynomial algebra in its semi-field of fractions. We can thus obtain, over
good semi-fields, the analog of classical correpondences between polynomials,
and varieties of zeros... For example, we show that the algebras of polynomial
functions over a tropical curves associated to a polynomial P, is, as in
classical algebraic geometry, the quotient of the polynomial algebra by the
ideal generated by P.


title: Proof of the Orthogonal Measurement Conjecture for Qubit States

abstract:
  The accessible information of general signal states is obtained by performing
a generalized measurement. In the case that the signal alphabet consists of two
states of a qubit system, it is proved that a von Neumann (orthogonal)
measurement is sufficient to reach the accessible information.


title: Stochastic deformation of a thermodynamic symplectic structure

abstract:
  A stochastic deformation of a thermodynamic symplectic structure is studied.
The stochastic deformation procedure is analogous to the deformation of an
algebra of observables like deformation quantization, but for an imaginary
deformation parameter (the Planck constant). Gauge symmetries of thermodynamics
and corresponding stochastic mechanics, which describes fluctuations of a
thermodynamic system, are revealed and gauge fields are introduced. A physical
interpretation to the gauge transformations and gauge fields is given. An
application of the formalism to a description of systems with distributed
parameters in a local thermodynamic equilibrium is considered.


title:
Cross section measurements of $\alpha$-induced reactions on $^{92,94}$Mo
  and $^{112}$Sn for $p$-process studies

abstract:
  The $^{92}$Mo($\alpha,n$)$^{95}$Ru, $^{94}$Mo($\alpha,n$)$^{97}$Ru, and
$^{112}$Sn($\alpha,\gamma$)$^{116}$Te cross sections were measured at the upper
end of the $p$-process Gamow window between 8.2 MeV and 11.1 MeV. Our results
are slightly lower than global Hauser-Feshbach calculations from the code
NON-SMOKER, but still within the uncertainty of the prediction. The
$^{112}$Sn($\alpha,\gamma$)$^{116}$Te cross section agrees well with a recently
measured thick-target cross section in the same energy range. For the
$^{92,94}$Mo($\alpha,n$) reactions the present data close to the reaction
thresholds could eliminate previous uncertainties within a factor of 20, and we
can present now useful comparisons to statistical model calculations with
different optical potentials.


title:
Phantom dark energy and cosmological solutions without the Big Bang
  singularity

abstract:
  The hypothesis is rapidly gaining popularity that the dark energy pervading
our universe is extra-repulsive ($-p>\rho$). The density of such a
substance(usually called phantom energy) grows with the cosmological expansion
and may become infinite in a finite time producing a Big Rip. In this Letter we
analyze the late stages of the universe evolution and demonstrate that the
presence of the phantom energy in the universe is not enough in itself to
produce the Big Rip. This singularity occurrence requires the fulfillment of
some additional, rather strong conditions. A more probable outcome of the
cosmological evolution is the decay of the phantom field into 'normal' matter.
  The second, more intriguing consequence of the presence of the phantom field
is the possibility to introduce a cosmological scenario that does not contain a
Big Bang. In the framework of this model the universe eternally expands, while
its density and other physical parameters oscillate over a wide range, never
reaching the Plank values. Thus, the universe evolution has no singularities at
all.


title:
Constraints on core-collapse supernova progenitors from correlations
  with H-alpha emission

abstract:
  We present observational constraints on the nature of the different
core-collapse supernova types through an investigation of the association of
their explosion sites with recent star formation, as traced by H-alpha +[NII]
line emission. We discuss results on the analysed data of the positions of 168
core-collapse supernovae with respect to the H-alpha emission within their host
galaxies. From our analysis we find that overall the type II progenitor
population does not trace the underlying star formation. Our results are
consistent with a significant fraction of SNII arising from progenitor stars of
less than 10 solar masses. We find that the supernovae of type Ib show a higher
degree of association with HII regions than those of type II (without
accurately tracing the emission), while the type Ic population accurately
traces the H-alpha emission. This implies that the main core-collapse supernova
types form a sequence of increasing progenitor mass, from the type II, to Ib
and finally Ic. We find that the type IIn sub-class display a similar degree of
association with the line emission to the overall SNII population, implying
that at least the majority of these SNe do not arise from the most massive
stars. We also find that the small number of SN `impostors' within our sample
do not trace the star formation of their host galaxies, a result that would not
be expected if these events arise from massive Luminous Blue Variable star
progenitors.


title: Satellite dynamics on the Laplace surface

abstract:
  The orbital dynamics of most planetary satellites is governed by the
quadrupole moment from the equatorial bulge of the host planet and the tidal
field from the Sun. On the Laplace surface, the long-term orbital evolution
driven by the combined effects of these forces is zero, so that orbits have a
fixed orientation and shape. The "classical" Laplace surface is defined for
circular orbits, and coincides with the planet's equator at small
planetocentric distances and with its orbital plane at large distances. A
dissipative circumplanetary disk should settle to this surface, and hence
satellites formed from such a disk are likely to orbit in or near the classical
Laplace surface. This paper studies the properties of Laplace surfaces. Our
principal results are: (i) if the planetary obliquity exceeds 68.875 deg there
is a range of semimajor axes in which the classical Laplace surface is
unstable; (ii) at some obliquities and planetocentric distances there is a
distinct Laplace surface consisting of nested eccentric orbits, which
bifurcates from the classical Laplace surface at the point where instability
sets in; (iii) there is also a "polar" Laplace surface perpendicular to the
line of nodes of the planetary equator on the planetary orbit; (iv) for
circular orbits, the polar Laplace surface is stable at small planetocentric
distances and unstable at large distances; (v) at the onset of instability this
polar Laplace surface bifurcates into two polar Laplace surfaces composed of
nested eccentric orbits.


title:
Abundance profiles in cooling-core clusters: a fossil record of past
  AGN-driven convection?

abstract:
  Central peaks in the iron abundance of intracluster plasma are a common
feature of cooling-core galaxy clusters. These abundance peaks have a much
broader profile than the stars of the central brightest cluster galaxy (BCG),
which produce the excess iron, indicating that metal-enriched plasma is
transported out of the BCG by some process such as turbulent diffusion. At the
same time, cooling-core clusters are likely heated by central active galactic
nuclei (AGNs) by means of jets, cosmic-ray bubbles, and convection. The recent
AGN-driven convection model of Chandran&Rasera predicts the turbulent velocity
profile in a steady-state cluster in which radiative cooling is balanced by
heating from a combination of AGN-driven convection and thermal conduction. We
use the velocity profiles as input into an advection/diffusion model for the
transport of metals in the intracluster medium, taking the iron to be injected
by the BCG. We compare the results of our model to XMM and Chandra observations
of eight clusters. Assuming a constant turbulence level over a cluster's
lifetime, the turbulent velocities in the model can explain the observed
abundance profiles in only five of the eight clusters. However, we go on to
develop an analytic fit of the turbulent velocity profile as a function of the
AGN power. We then deduce for each cluster the average AGN power (during the
past 10 Gyr) required to match the abundance profiles. The required average
values are between 10^43 and 2.10^44 erg/s, while the present AGN powers span a
much larger range from 6.10^41 (Virgo) to 2.10^44 erg/s (Hydra A). Our results
suggest that AGN-driven convection can account for the observed abundance
profiles if the AGN power varies over a cluster's lifetime between Virgo-like
and Hydra-A-like values, with average values in the above-quoted range.


title: Local control of area-preserving maps

abstract:
  We present a method of control of chaos in area-preserving maps. This method
gives an explicit expression of a control term which is added to a given
area-preserving map. The resulting controlled map which is a small and suitable
modification of the original map, is again area-preserving and has an invariant
curve whose equation is explicitly known.


title: Multiple Breakup of Higher-Order Spatial Solitons

abstract:
  The breakup of high-order spatial solitons propagating in an AlGaAs slab
waveguide is studied. We experimentally observe the breakup of such beams into
multiple fragments and identify the mechanism of this breakup as the combined
effect of two- and three-photon-absorption. We show that the multiple breakup
persists even when the value of two-photon-absorption is reduced by an order of
magnitude owing to the high value of three-photon-absorption of AlGaAs at the
half band-gap. The experimental results extend known mechanism of soliton
breakup induced by two-photon-absorption and agree well with numerical beam
propagation simulations.


title: Bayesian Analysis of Value-at-Risk with Product Partition Models

abstract:
  In this paper we propose a novel Bayesian methodology for Value-at-Risk
computation based on parametric Product Partition Models. Value-at-Risk is a
standard tool to measure and control the market risk of an asset or a
portfolio, and it is also required for regulatory purposes. Its popularity is
partly due to the fact that it is an easily understood measure of risk. The use
of Product Partition Models allows us to remain in a Normal setting even in
presence of outlying points, and to obtain a closed-form expression for
Value-at-Risk computation. We present and compare two different scenarios: a
product partition structure on the vector of means and a product partition
structure on the vector of variances. We apply our methodology to an Italian
stock market data set from Mib30. The numerical results clearly show that
Product Partition Models can be successfully exploited in order to quantify
market risk exposure. The obtained Value-at-Risk estimates are in full
agreement with Maximum Likelihood approaches, but our methodology provides
richer information about the clustering structure of the data and the presence
of outlying points.

categories: q-fin.RM physics.soc-ph q-fin.ST stat.AP stat.ME


title: Using SPICA Space Telescope to characterize Exoplanets

abstract:
  We present the 3.5m SPICA space telescope, a proposed Japanese-led JAXA-ESA
mission scheduled for launch around 2017. The actively cooled (<5 K), single
aperture telescope and monolithic mirror will operate from ~3.5 to ~210 um and
will provide superb sensitivity in the mid- and far-IR spectral domain (better
than JWST at lambda > 18 um). SPICA is one of the few space missions selected
to go to the next stage of ESA's Cosmic Vision 2015-2025 selection process. In
this White Paper we present the main specifications of the three instruments
currently baselined for SPICA: a mid-infrared (MIR) coronagraph (~3.5 to ~27
um) with photometric and spectral capabilities (R~200), a MIR wide-field camera
and high resolution spectrometer (R~30,000), and a far-infrared (FIR ~30 to
~210 um) imaging spectrometer - SAFARI - led by a European consortium. We
discuss their capabilities in the context of MIR direct observations of
exo-planets (EPs) and multiband photometry/high resolution spectroscopy
observations of transiting exo-planets. We conclude that SPICA will be able to
characterize the atmospheres of transiting exo-planets down to the super-Earth
size previously detected by ground- or space-based observatories. It will also
directly detect and characterize Jupiter/Neptune-size planets orbiting at
larger separation from their parent star (>5-10 AU), by performing quantitative
atmospheric spectroscopy and studying proto-planetary and debris disks. In
addition, SPICA will be a scientific and technological precursor for future,
more ambitious, IR space missions for exo-planet direct detection as it will,
for example, quantify the prevalence exo-zodiacal clouds in planetary systems
and test coronographic techniques, cryogenic systems and lightweight, high
quality telescopes. (abridged)


title: Dispersion compensation in atom interferometry by a Sagnac phase

abstract:
  We reanalyzed our atom interferometer measurement of the electric
polarizability of lithium now accounting for the Sagnac effect due to Earth
rotation. The resulting correction to the polarizability is very small but the
visibility as a function of the applied phase shift is now better explained.
The fact that the Sagnac and polarizability phase shifts are both proportional
to $v^{-1}$, where $v$ is the atom velocity, suggests that a phase shift of the
Sagnac type could be used as a counterphase to compensate the electric
polarizability phase shift. This exact compensation opens the way to higher
accuracy measurements of atomic polarizabilities and we discuss how this can be
practically done and the final limitations of the proposed technique.


title: Possibility of High Tc Superconductivity in doped Graphene

abstract:
  Graphene is at the forefront of condensed matter sciences, because of a
variety of interesting phenomena it supports. If graphene could support high Tc
superconductivity, after doping for example, it will make it even more
valuable. Some authors have suggested possibility of superconductivity in
graphite like systems. However, an early suggestion of one of us (Baskaran) was
unique in the sense it combined Pauling's classic idea of resonating valence
bond physics with band theory to obtain some exciting results for
superconductivity. Black-Schaffer and Doniach took this approach further and
found an unconventional d + id order parameter. To sharpen our theory and get
more convincing and reliable results for superconductivity, we introduce a
correlated variational BCS ground state wavefunction and perform extensive
Monte Carlo study of the repulsive Hubbard model on the honeycomb lattice. We
find that undoped graphene is not a superconductor, consistent with experiments
and also mean field results. Interestingly, an appreciable superconducting
order is obtained around an optimal doping. This result and a supportive slave
particle analysis together suggest the possibility of high temperature
superconductivity in doped graphene.


title: Ideals in Parabolic Subalgebras of Simple Lie Algebras

abstract:
  We study ad-nilpotent ideals of a parabolic subalgebra of a simple Lie
algebra. Any such ideal determines an antichain in a set of positive roots of
the simple Lie algebra. We give a necessary and sufficient condition for an
antichain to determine an ad-nilpotent ideal of the parabolic. We write down
all such antichains for the classical simple Lie algebras and in particular
recover the results of D. Peterson. In section 2 of the paper we study the
unique ideal in a parabolic which is irreducible as a module for the reductive
part and give several equivalent statements that are satisfied by the
corresponding subset of roots.


title:
Optimization problem for extremals of the trace inequality in domains
  with holes

abstract:
  We study the Sobolev trace constant for functions defined in a bounded domain
$\O$ that vanish in the subset $A.$ We find a formula for the first variation
of the Sobolev trace with respect to hole. As a consequence of this formula, we
prove that when $\O$ is a centered ball, the symmetric hole is critical when we
consider deformation that preserve volume but is not optimal for some case.


title: keV Warm Dark Matter via the Supersymmetric Higgs Portal

abstract:
  Warm dark matter (WDM) may resolve the possible conflict between observed
galaxy halos and the halos produced in cold dark matter (CDM) simulations. Here
we present an extension of MSSM to include WDM by adding a gauge singlet
fermion, \bar{\chi}, with a portal-like coupling to the MSSM Higgs doublets.
This model has the property that the dark matter is {\it necessarily warm}. In
the case where M_{\bar{\chi}} is mainly due to electroweak symmetry breaking,
the \bar{\chi} mass is completely determined by its relic density and the
reheating temperature, T_R. For 10^2 GeV < T_{R} < 10^{5} GeV$, the range
allowed by \bar{chi} production via thermal Higgs annihilation, the \bar{\chi}
mass is in the range 0.3-4 keV, precisely the range required for WDM. The
primordial phase-space density, Q, can directly account for that observed in
dwarf spheroidal galaxies, Q \approx 5 x 10^{6}(eV/cm^3)/(km/s)^3,, when the
reheating temperature is in the range T_R \approx 10-100 TeV, in which case
M_{\bar{\chi}} \approx 0.45 keV. The free-streaming length is in the range
0.3-4 Mpc, which can be small enough to alleviate the problems of
overproduction of galaxy substructure and low angular momentum of CDM
simulations.


title:
Pathwise uniqueness for stochastic heat equations with H\"older
  continuous coefficients: the white noise case

abstract:
  We prove pathwise uniqueness for solutions of parabolic stochastic pde's with
multiplicative white noise if the coefficient is H\"older continuous of index
$\gamma>3/4$. The method of proof is an infinite-dimensional version of the
Yamada-Watanabe argument for ordinary stochastic differential equations.


title:
What do stars tell us about planets? Asteroseismology of exoplanet-host
  stars

abstract:
  Studying the internal structure of exoplanet-host stars compared to that of
similar stars without detected planets is particularly important for the
understanding of planetary formation. The observed average overmetallicity of
stars with planets is an interesting point in that respect. In this framework,
asteroseismic studies represent an excellent tool to determine the structural
differences between stars with and without detected planets. It also leads to
more precise values of the stellar parameters like mass, gravity, effective
temperature, than those obtained from spectroscopy alone. Interestingly enough,
the detection of stellar oscillations is obtained with the same instruments as
used for the discovery of exoplanets, both from the ground and from space. The
time scales however are very different, as the oscillations of solar type stars
have periods around five to ten minutes, while the exoplanets orbits may go
from a few days up to many years. Here I discuss the asteroseismology of
exoplanet-host stars, with a few examples.


title:
Multiscaling behavior in the volatility return intervals of Chinese
  indices

abstract:
  We investigate the probability distribution of the return intervals $\tau$
between successive 1-min volatilities of two Chinese indices exceeding a
certain threshold $q$. The Kolmogorov-Smirnov (KS) tests show that the two
indices exhibit multiscaling behavior in the distribution of $\tau$, which
follows a stretched exponential form $f_q(\tau/< \tau >)\sim e^{- a(\tau/ <
\tau >)^{\gamma}}$ with different correlation exponent $\gamma$ for different
threshold $q$, where $<\tau>$ is the mean return interval corresponding to a
certain value of $q$. An extended self-similarity analysis of the moments
provides further evidence of multiscaling in the return intervals.


title: Control of coherence resonance in semiconductor superlattices

abstract:
  We study the effect of time-delayed feedback control and Gaussian white noise
on the spatio-temporal charge dynamics in a semiconductor superlattice. The
system is prepared in a regime where the deterministic dynamics is close to a
global bifurcation, namely a saddle-node bifurcation on a limit cycle ({\it
SNIPER}). In the absence of control, noise can induce electron charge front
motion through the entire device, and coherence resonance is observed. We show
that with appropriate selection of the time-delayed feedback parameters the
effect of coherence resonance can either be enhanced or destroyed, and the
coherence of stochastic domain motion at low noise intensity is dramatically
increased. Additionally, the purely delay-induced dynamics in the system is
investigated, and a homoclinic bifurcation of a limit cycle is found.


title: An analytical approach to initiation of propagating fronts

abstract:
  We consider the problem of initiation of a propagating wave in a
one-dimensional excitable fibre. In the Zeldovich-Frank-Kamenetsky equation,
a.k.a. Nagumo equation, the key role is played by the "critical nucleus''
solution whose stable manifold is the threshold surface separating initial
conditions leading to initiation of propagation and to decay. Approximation of
this manifold by its tangent linear space yields an analytical criterion of
initiation which is in a good agreement with direct numerical simulations.


title: Fields from a relativistic magnetic explosion

abstract:
  Following Prendergast we study the relativistically expanding electromagnetic
fields generated by an axisymmetric explosion of magnetic energy in a small
volume. The magnetic field expands uniformly either within a cone or in all
directions and it is therefore accompanied by an electric field. In the highly
conducting plasma the charges move to annul the electric field in the frame of
the moving plasma. The solutions presented are analytical and semi-analytical.
We find that the time-scale for the winding up of the initial magnetic field is
crucial, as short time-scales lead to strong radiant fields. Assuming a
magnetic field of $10^{13}Gauss$ emerging from a magnetosphere of $10^{9}cm$ we
end with a jet when confined by a pressure environment that falls more slowly
than $r^{-4}$. The jet carries energy of $10^{51}erg$, which is mostly due to
differential rotation at the base.


title: The Casimir effect in the nanoworld

abstract:
  The Casimir effect is a force arising in the macroscopic world as a result of
radiation pressure of vacuum fluctuations. It thus plays a key role in the
emerging domain of nano-electro-mechanical systems (NEMS). This role is
reviewed in the present paper, with discussions of the influence of the
material properties of the mirrors, as well as the geometry dependence of the
Casimir effect between corrugated mirrors. In particular, the lateral component
of the Casimir force and restoring torque between metal plates with misaligned
corrugations are evaluated.


title:
A broad-band spectral analysis of eight radio loud type 1 AGN selected
  in the hard X-ray band

abstract:
  Starting from a complete sample of type I AGN observed by INTEGRAL in the
20-40 keV band, we have selected a set of 8 AGN which can be classified as
radio loud objects according to their 1.4 GHz power density, radio to hard
X-ray flux flux density ratio and radio morphology. The sample contains 6 Broad
Line Radio Galaxies and 2 candidate ones. Most of the objects in our sample
display a double lobe morphology, both on small and large scales. For all the
objects, we present broad-band (1-110 keV) spectral analysis using INTEGRAL
observations together with archival XMM-Newton, Chandra, Swift/XRT and
Swift/BAT data. We constrain the primary continuum (photon index and cut-off
energy), intrinsic absorption and reprocessing features (iron line and
reflection) in most of the objects. The sources analysed here show remarkable
similarities to radio quiet type 1 AGN with respect to most of the parameters
analysed; we only find marginal evidence for weaker reprocessing features in
our objects compared to their radio quiet counterparts. Similarly we do not
find any correlation between the spectral parameters studied and the source
core dominance or radio to 20-100 keV flux density ratios, suggesting that what
makes our objects radio loud has no effect on their high energy
characteristics.


title:
New Two Dimensional Massless Field Theory from Bagger-Lambert-Gustavsson
  Model

abstract:
  By compactifying the Bagger-Lambert-Gustavsson model on $\mathbb{R}^{1,1}
\times S^1$, we obtain a new two dimensional massless field theory with
dynamical fields valued in the Lie 3-algebra $\mathcal{A}$ coupled with an
SO(1,1) scalar and vector field which are valued in the set $End(\mathcal{A})$
of the endomorphisms of the Lie 3-algebra. In the limit $g_{BLG} \to \infty$
the theory reduces to a supersymmetric Lie 3-valued generalization of the
Green-Schwarz superstring in the light-cone gauge.


title: Linear Kernelizations for Restricted 3-Hitting Set Problems

abstract:
  The 3-\textsc{Hitting Set} problem is also called the \textsc{Vertex Cover}
problem on 3-uniform hypergraphs. In this paper, we address kernelizations of
the \textsc{Vertex Cover} problem on 3-uniform hypergraphs. We show that this
problem admits a linear kernel in three classes of 3-uniform hypergraphs. We
also obtain lower and upper bounds on the kernel size for them by the
parametric duality.


title:
Does The Lattice Zero Momentum Gluon Propagator for Pure Gauge SU(3)
  Yang-Mills Theory Vanish in the Infinite Volume Limit?

abstract:
  The Cucchieri-Mendes bounds for the gluon propagator are discussed for the
four dimensional pure gauge SU(3) theory. Assuming a pure power law dependence
on the inverse of the lattice volume, the lattice data gives a vanishing zero
momentum gluon propagator in the infinite volume limit. Our investigation shows
that this result is robust against variations of the lattice volumes and
corrections to the power law. Moreover, it is consistent with the
Gribov-Zwanziger horizon condition and contradicts the SU(2) analysis, which
assumed the same type of dependence on the inverse of the volume. Our analysis
considers also more general ansatze that, although not conclusive, open the
possibility of having $D(0) \ne 0$ in the infinite volume limit. A solution to
this puzzle requires further investigations.


title:
On Duality between Local Maximum Stable Sets of a Graph and its
  Line-Graph

abstract:
  G is a Koenig-Egervary graph provided alpha(G)+ mu(G)=|V(G)|, where mu(G) is
the size of a maximum matching and alpha(G) is the cardinality of a maximum
stable set. S is a local maximum stable set of G if S is a maximum stable set
of the closed neighborhood of S. Nemhauser and Trotter Jr. proved that any
local maximum stable set is a subset of a maximum stable set of G. In this
paper we demonstrate that if S is a local maximum stable set, the subgraph H
induced by the closed neighborhood of S is a Koenig-Egervary graph, and M is a
maximum matching in H, then M is a local maximum stable set in the line graph
of G.


title: The effect of gas-dynamics on semi-analytic modeling of cluster galaxies

abstract:
  We study the degree to which non-radiative gas dynamics affects the merger
histories of haloes along with subsequent predictions from a semi-analytic
model (SAM) of galaxy formation. To this aim, we use a sample of dark matter
only and non-radiative SPH simulations of four massive clusters. The presence
of gas-dynamical processes (e.g. ram-pressure from the hot ICM) makes haloes
more fragile in the runs which include gas. This results in a 25 per cent
decrease in the total number of subhaloes at z = 0. The impact on the galaxy
population predicted by SAMs is complicated by the presence of "orphan"
galaxies, i.e. galaxies whose parent substructures are reduced below the
resolution limit of the simulation. In the model employed in our study, these
galaxies survive for a residual merging time that is computed using a variation
of the Chandrasekhar formula. Due to ram-pressure stripping, haloes in gas
simulations tend to be less massive than their counterparts in the dark matter
simulations. The resulting merging times for satellite galaxies are then longer
in these simulations. On the other hand, the presence of gas influences the
orbits of haloes making them on average more circular and therefore reducing
the estimated merging times with respect to the dark matter only simulation.
This effect is particularly significant for the most massive satellites and is
(at least in part) responsible for the fact that brightest cluster galaxies in
runs with gas have stellar masses which are about 25 per cent larger than those
obtained from dark matter only simulations. Our results show that gas-dynamics
has only a marginal impact on the statistical properties of the galaxy
population, but that its impact on the orbits and merging times of haloes
strongly influences the assembly of the most massive galaxies.


title: Nonlinear aspects of astrobiological research

abstract:
  Several aspects of mathematical astrobiology are discussed. It is argued that
around the time of the origin of life the handedness of biomolecules must have
established itself through an instability. Possible pathways of producing a
certain handedness include mechanisms involving either autocatalysis or,
alternatively, epimerization as governing effects. Concepts for establishing
hereditary information are discussed in terms of the theory of hypercycles.
Instabilities toward parasites and possible remedies by invoking spatial extent
are reviewed. Finally, some effects of early life are discussed that
contributed to modifying and regulating atmosphere and climate of the Earth,
and that could have contributed to the highly oxidized state of its crust.


title:
Replica overlap and covering time for the Wiener sausages among
  Poissonian obstacles

abstract:
  We study two objects concerning the Wiener sausage among Poissonian
obstacles. The first is the asymptotics for the \textit{replica overlap}, which
is the intersection of two independent Wiener sausages. We show that it is
asymptotically equal to their union. This result confirms that the localizing
effect of the media is so strong as to completely determine the motional range
of particles. The second is an estimate on the \textit{covering time}. It is
known that the Wiener sausage avoiding Poissonian obstacles up to time $t$ is
confined in some `clearing' ball near the origin and almost fills it. We prove
here that the time needed to fill the confinement ball has the same order as
its volume.


title: CP violating phases in mu-e conversion

abstract:
  Experiments are planned to improve the sensitivity of mu-e conversion from
the current ~ 10^{-12} to 10^{-16} - 10^{-18}. If the muon (bound to the
nucleus) could be polarised, a spin asymmetry of the final state electron is
sensitive to CP violating phases on lepton flavour violating operators. This is
similar to extracting phases from asymmetries in the final state spin and phase
space distributions of mu to 3e and mu to e gamma.


title: Quantum Bases in Uq(g)

abstract:
  This paper is devoted to analize inside the infinitely many possible bases of
Uq(g), same that can be considered "more equal then others". The element of
selection has been a privileged relation with the bialgebra. A new parameter z'
has been found that determines the commutation relations, independent from the
z=log(q) that defines Uq(g). Both z and z' are necessary to fix the relations
between the basic set and its coproducts. Three cases are particularly
relevant: the analytical set with z'=z, the Lie set with Lie-like commutation
relations (for z'=0) and the canonical/crystal basis with z' infinity. To
simplify the exposition, we discuss in details the easy generalizable case of
Uq(su(2)).


title:
A large stellar evolution database for population synthesis studies. IV.
  Integrated properties and spectra

abstract:
  This paper is the 4th in a series describing the latest additions to the
BaSTI stellar evolution database, which consists of a large set of homogeneous
models and tools for population synthesis studies. Here we present a new set of
low and high resolution synthetic spectra based on the BaSTI stellar models,
covering a large range of simple stellar populations (SSPs) for both scaled
solar and alpha-enhanced metal mixtures. This enables a completely consistent
study of the photometric and spectroscopic properties of both resolved and
unresolved stellar populations, and allows us to make detailed tests on their
integrated properties. Our low resolution spectra are suitable for deriving
broadband magnitudes and colors in any photometric system. These spectra cover
the full wavelength range (9-160000nm) and include all evolutionary stages up
to the end of AGB evolution. Our high resolution spectra are suitable for
studying the behaviour of line indices and we have tested them against a large
sample of Galactic globular clusters. We find that the range of ages, iron
abundances [Fe/H], and degree of alpha-enhancement predicted by the models
matches observed values very well. We have also tested the global consistency
of the BaSTI models by making detailed comparisons between ages and
metallicities derived from isochrone fitting to observed CMDs, and from line
index strengths, for the Galactic globular cluster 47Tuc and the open cluster
M67. For 47Tuc we find reasonable agreement between the 2 methods, within the
estimated errors. From the comparison with M67 we find non-negligible effects
on derived line indices caused by statistical fluctuations, which are a result
of the specific method used to populate an isochrone and assign appropriate
spectra to individual stars. (abridged)


title: Electromagnetic Light in Medium of Polarized Atoms $^3$He

abstract:
  First, it is predicted that polarized atoms $^3$He increase a value of speed
electromagnetic waves. This reasoning implies that the velocity of
electromagnetic waves into gas consisting of polarized atoms $^3$He is rather
than one in vacuum.


title:
Chern classes, K-theory and Landweber exactness over nonregular base
  schemes

abstract:
  The purpose of this paper is twofold. First, we use the motivic Landweber
exact functor theorem to deduce that the Bott inverted infinite projective
space is homotopy algebraic $K$-theory. The argument is considerably shorther
than any other known proofs and serves well as an illustration of the
effectiveness of Landweber exactness. Second, we dispense with the regularity
assumption on the base scheme which is often implicitly required in the notion
of oriented motivic ring spectra. The latter allows us to verify the motivic
Landweber exact functor theorem and the universal property of the algebraic
cobordism spectrum for every noetherian base scheme of finite Krull dimension.


title:
Systematic uncertainties in MonteCarlo simulations of the atmospheric
  muon flux in the 5-line ANTARES detector

abstract:
  The ANTARES detector was operated in a configuration with 5 lines for a
period of 10 months from February until November 2007. The duty cycle was
better than 80% during this period and almost 2*10**7 atmospheric muon triggers
were collected. This large sample was used to test Monte Carlo simulation
programs and to evaluate possible systematic effects due to uncertainties on
environmental parameters and detector description. First results are presented
and discussed.


title: Large-scale magnetic topologies of early M dwarfs

abstract:
  We present here additional results of a spectropolarimetric survey of a small
sample of stars ranging from spectral type M0 to M8 aimed at investigating
observationally how dynamo processes operate in stars on both sides of the full
convection threshold (spectral type M4).
  The present paper focuses on early M stars (M0--M3), i.e. above the full
convection threshold. Applying tomographic imaging techniques to time series of
rotationally modulated circularly polarised profiles collected with the NARVAL
spectropolarimeter, we determine the rotation period and reconstruct the
large-scale magnetic topologies of 6 early M dwarfs. We find that early-M stars
preferentially host large-scale fields with dominantly toroidal and
non-axisymmetric poloidal configurations, along with significant differential
rotation (and long-term variability); only the lowest-mass star of our
subsample is found to host an almost fully poloidal, mainly axisymmetric
large-scale field ressembling those found in mid-M dwarfs.
  This abrupt change in the large-scale magnetic topologies of M dwarfs
(occuring at spectral type M3) has no related signature on X-ray luminosities
(measuring the total amount of magnetic flux); it thus suggests that underlying
dynamo processes become more efficient at producing large-scale fields (despite
producing the same flux) at spectral types later than M3. We suspect that this
change relates to the rapid decrease in the radiative cores of low-mass stars
and to the simultaneous sharp increase of the convective turnover times (with
decreasing stellar mass) that models predict to occur at M3; it may also be (at
least partly) responsible for the reduced magnetic braking reported for
fully-convective stars.


title:
Linearizing non-linear inverse problems and an application to inverse
  backscattering

abstract:
  We propose an abstract approach to prove local uniqueness and conditional
H\"older stability to non-linear inverse problems by linearization. The main
condition is that, in addition to the injectivity of the linearization $A$, we
need a stability estimate for $A$ as well. That condition is satisfied in
particular, if $A^*A$ is an elliptic pseudo-differential operator. We apply
this scheme to show uniqueness and H\"older stability for the inverse
backscattering problem for the acoustic equation near a constant sound speed.


title:
Randomised Variable Neighbourhood Search for Multi Objective
  Optimisation

abstract:
  Various local search approaches have recently been applied to machine
scheduling problems under multiple objectives. Their foremost consideration is
the identification of the set of Pareto optimal alternatives. An important
aspect of successfully solving these problems lies in the definition of an
appropriate neighbourhood structure. Unclear in this context remains, how
interdependencies within the fitness landscape affect the resolution of the
problem.
  The paper presents a study of neighbourhood search operators for multiple
objective flow shop scheduling. Experiments have been carried out with twelve
different combinations of criteria. To derive exact conclusions, small problem
instances, for which the optimal solutions are known, have been chosen.
Statistical tests show that no single neighbourhood operator is able to equally
identify all Pareto optimal alternatives. Significant improvements however have
been obtained by hybridising the solution algorithm using a randomised variable
neighbourhood search technique.


title: Monopolium production from photon fusion at the Large Hadron Collider

abstract:
  Magnetic monopoles have attracted the attention of physicists since the
founding of the electromagnetic theory. Their search has been a constant
endeavor which was intensified when Dirac established the relation between the
existence of monopoles and charge quantization. However, these searches have
been unsuccessful. We have recently proposed that monopolium, a
monopole-antimonopole bound state, so strongly bound that it has a relatively
small mass, could be easier to find and become an indirect but clear signature
for the existence of magnetic monopoles. In here we extend our previous
analysis for its production to two photon fusion at LHC energies.


title: All-sky search of NAUTILUS data

abstract:
  A search for periodic gravitational-wave signals from isolated neutron stars
in the NAUTILUS detector data is presented. We have analyzed half a year of
data over the frequency band $<922.2; 923.2>$ Hz, the spindown range
$<-1.463\times10^{-8}; 0>$ Hz/s and over the entire sky. We have divided the
data into 2 day stretches and we have analyzed each stretch coherently using
matched filtering. We have imposed a low threshold for the optimal detection
statistic to obtain a set of candidates that are further examined for
coincidences among various data stretches. For some candidates we have also
investigated the change of the signal-to-noise ratio when we increase the
observation time from two to four days. Our analysis has not revealed any
gravitational-wave signals. Therefore we have imposed upper limits on the
dimensionless gravitational-wave amplitude over the parameter space that we
have searched. Depending on frequency, our upper limit ranges from $3.4 \times
10^{-23}$ to $1.3 \times 10^{-22}$. We have attempted a statistical
verification of the hypotheses leading to our conclusions. We estimate that our
upper limit is accurate to within 18%.


title: Flavour-Oscillation Clocks and the Geometricity of General Relativity

abstract:
  I look at the 'flavour-oscillation clocks' proposed by D.V. Ahluwalia, and
two arguments of his suggesting that such clocks might behave in a way that
threatens the geometricity of general relativity (GR). The first argument
states that the behaviour of these clocks in the vicinity of a rotating
gravitational source implies a non-geometric element of gravity. I argue that
the phenomenon is best seen as an instance of violation of the 'clock
hypothesis', and therefore does not threaten the geometrical nature of
gravitation. Ahluwalia's second argument, for the 'incompleteness' of general
relativity, involves the idea that flavour-oscillation clocks can detect
constant gravitational potentials. I argue that the purported
'incompleteness-establishing' result is in fact one that applies to all clocks.
It is entirely derivable from GR, does not result in the observability of the
potential, and is not at odds with any of GR's foundations.


title: The longest minimum-weight path in a complete graph

abstract:
  We consider the minimum-weight path between any pair of nodes of the n-vertex
complete graph in which the weights of the edges are i.i.d. exponentially
distributed random variables. We show that the longest of these minimum-weight
paths has about \alpha^* \log n$ edges where \alpha^* ~ 3.5911 is the unique
solution of the equation $alpha log(alpha) - \alpha =1. This answers a question
posed by Janson (1999).


title:
A Bayesian approach to power-spectrum significance estimation, with
  application to solar neutrino data

abstract:
  The usual procedure for estimating the significance of a peak in a power
spectrum is to calculate the probability of obtaining that value or a larger
value by chance, on the assumption that the time series contains only noise
(e.g. that the measurements were derived from random samplings of a Gaussian
distribution). However, it is known that one should regard this P-Value
approach with caution. As an alternative, we here examine a Bayesian approach
to estimating the significance of a peak in a power spectrum. This approach
requires that we consider explicitly the hypothesis that the time series
contains a periodic signal as well as noise. The challenge is to identify a
probability distribution function for the power that is appropriate for this
hypothesis. We propose what seem to be reasonable conditions to require of this
function, and then propose a simple function that meets these requirements. We
also propose a consistency condition, and check to see that our function
satisfies this condition. We find that the Bayesian significance estimates are
considerably more conservative than the conventional estimates. We apply this
procedure to three recent analyses of solar neutrino data: (a) bimodality of
GALLEX data; (b) power spectrum analysis of Super-Kamiokande data; and (c) the
combined analysis of radiochemical neutrino data and irradiance data.


title:
Structural stability of attractor-repellor endomorphisms with
  singularities

abstract:
  We prove a theorem on structural stability of smooth attractor-repellor
endomorphisms of compact manifolds, with singularities. By attractor-repellor,
we mean that the non-wandering set of the dynamics $f$ is the disjoint union of
a repulsive compact subset with a hyperbolic attractor on which $f$ acts
bijectively. The statement of this result is both infinitesimal and dynamical.
Up to our knowledge, this is the first in this hybrid direction. Our results
generalize also a Mather's theorem in singularity theory which states that
infinitesimal stability implies structural stability for composed mappings, to
the larger category of laminations.


title:
Theoretical modeling of propagation of magneto-acoustic waves in
  magnetic regions below sunspots

abstract:
  We use 2D numerical simulations and eikonal approximation, to study
properties of MHD waves traveling below the solar surface through the magnetic
structure of sunspots. We consider a series of magnetostatic models of sunspots
of different magnetic field strengths, from 10 Mm below the photosphere to the
low chromosphere. The purpose of these studies is to quantify the effect of the
magnetic field on local helioseismology measurements by modeling waves excited
by sub-photospheric sources. Time-distance propagation diagrams and wave travel
times are calculated for models of various field strength and compared to the
non-magnetic case. The results clearly indicate that the observed time-distance
helioseismology signals in sunspot regions correspond to fast MHD waves. The
slow MHD waves form a distinctly different pattern in the time-distance
diagram, which has not been detected in observations. The numerical results are
in good agreement with the solution in the short-wavelength (eikonal)
approximation, providing its validation. The frequency dependence of the travel
times is in a good qualitative agreement with observations.


title: Competing risks within shock models

abstract:
  We consider a competing risks model, in which system failures are due to one
out of two mutually exclusive causes, formulated within the framework of shock
models driven by bivariate Poisson process. We obtain the failure densities and
the survival functions as well as other related quantities under three
different schemes. Namely, system failures are assumed to occur at the first
instant in which a random constant threshold is reached by (a) the sum of
received shocks, (b) the minimum of shocks, (c) the maximum of shocks.


title: Does negative refraction make a perfect lens?

abstract:
  A discussion of a question, studied earlier by V.Veselago in 1967 and by J.
Pendry in 2000, is given. The question is: can a slab of the material with
negative refraction make a perfect lens? Pendry's conclusion was: yes, it can.
Our conclusion is: no, in practice it cannot, because of the fluctuations of
the refraction coefficient of the slab. Resolution ability of linear
isoplanatic optical instruments is discussed.


title: Correlation function in Field - Feynman hadronization model

abstract:
  Very successful hadronization model for the production of mesons in the jets
of initial quarks was proposed thirty years ago by Field and Feynman. The model
is used so far in the design of experiments and for comparison with the
experimental data. In this work it is shown that correlation function in that
model, as a function of the energies of two final hadrons has interesting
properties (energies are taken in fractions of initial quark energy, and equal
$z_{1}$ and $z_{2}$, respectively). In particular, for some pairs of mesons
there are kinematic regions over variable $z_{2}$ (at fixed values of $z_{1}$),
where it is positive and unexpectedly large. The experimental investigation of
the correlation functions in these kinematic regions has twofold interest, from
one side it can help to investigate some delicate properties of quark jets and
from the other side can help to verify the physical suppositions of model, and
to obtain more precise values of parameters.


title: Fermion-Fermion Bound State Condition for Scalar Exchanges

abstract:
  The condition for the existence of a bound state between two fermions
exchanging massive scalars is derived. For low scalar mass, we reproduce the
scalar field model result. The high scalar mass result exhibits a somewhat
different inequality condition.


title:
Competition between antiferromagnetic instability and frustrations in
  Fe-Se

abstract:
  Using linear-response density-functional theory, we obtain the magnetic
interactions in the several iron pnictides. The ground state has been found to
be non-collinear in FeSe, with a large continuum of nearly degenerate states
lying very close to the magnetic "striped" structure. The presence of
non-collinearity also seems to be a generic feature of iron pnictides when the
Fe moment is small. At small R_{Fe-Se} the system is itinerant: strong
frustration give rise to excess of spin entropy, long ranged interactions
create incommensurate orderings and strong biquadratic (or ring) couplings
violate the applicability of Heisenberg model. There is a smooth transition to
more localized behavior as R_{Fe-Se} increases: stable magnetic orbital order
develops which favor long range AFM stripe ordering with strongly anisotropic
in-plane exchange couplings. The stabilization of the stripe magnetic order is
accompanied by the inversion of the exchange coupling.


title: A Full 24-Parameter MSSM Exploration

abstract:
  Up until now a complete scan in all phenomenologically relevant directions of
the MSSM at the TeV scale for performing global fit has not been done. Given
the imminent start of operation of the LHC, this is a major gap on our quest to
discovering and understanding the physical implications of low energy
supersymmetry. The main reason for this is the large number of parameters
involved that makes it computationally extremely expensive using the
traditional methods. In this talk I demonstrate that with advanced sampling
techniques the problem is solvable. The results from the explored 24-parameter
TeV scale MSSM (phenoMSSM) are remarkably distinct from previous studies and
are independent of models for supersymmetry breaking and mediation mechanisms.
Hence they are a more robust guide to searches for supersymmetry and dark
matter.


title: Simulated self-organisation of death by inherited mutations

abstract:
  An agent-based computer simulation of death by inheritable mutations in a
changing environment shows a maximal population, or avoids extinction, at so
intermediate mutation rate of the individuals. Thus death seems needed to al
for evolution of the fittest, as required by a changing environment.


title: Preparing materials with a desired refraction coefficient

abstract:
  A recipe is given for creating material with a desired refraction coefficient
by embedding many small particles in a given material. To implement practically
this recipe, some technological problems are to be solved. These problems are
formulated.


title:
The Hodge--Poincar\'e polynomial of the moduli spaces of stable vector
  bundles over an algebraic curve

abstract:
  Let X be a nonsingular complex projective variety that is acted on by a
reductive group $G$ and such that $X^{ss} \neq X_{(0)}^{s}\neq \emptyset$. We
give formulae for the Hodge--Poincar\'e series of the quotient $X_{(0)}^s/G$.
We use these computations to obtain the corresponding formulae for the
Hodge--Poincar\'e polynomial of the moduli space of properly stable vector
bundles when the rank and the degree are not coprime. We compute explicitly the
case in which the rank equals 2 and the degree is even.


title:
Dynamic optical lattices: two-dimensional rotating and accordion
  lattices for ultracold atoms

abstract:
  We demonstrate a novel experimental arrangement which rotates a 2D optical
lattice at frequencies up to several kilohertz. Ultracold atoms in such a
rotating lattice can be used for the direct quantum simulation of strongly
correlated systems under large effective magnetic fields, allowing
investigation of phenomena such as the fractional quantum Hall effect. Our
arrangement also allows the periodicity of a 2D optical lattice to be varied
dynamically, producing a 2D accordion lattice.


title: Modelling Richardson orbits for SO_N via Delta-filtered modules

abstract:
  We study the Delta-filtered modules for the Auslander algebra of
k[T]/T^n\rtimes C_2 where C_2 is the cyclic group of order two. The motivation
for this is the bijection between parabolic orbits in the nilradical of a
parabolic subgroup of SL_n and certain Delta-filtered modules for the Auslander
algebra of k[T]/T^n as found by Hille and Roehrle and Bruestle et al. Under
this bijection, the Richardson orbit (i.e. the dense orbit) corresponds to the
Delta-filtered module without self-extensions. It has remained an open problem
to describe such a correspondence for other classical groups.
  In this paper, we establish the Auslander algebra of k[T]/T^n\rtimes C_2 as
the right candidate for the orthogonal groups. In particular, for any parabolic
subgroup of an orthogonal group we construct a map from parabolic orbits to
Delta-filtered modules and show that in the case of the Richardson orbit, the
result has no self-extensions. One of the consequences of our work is that we
are able to describe the extensions between special classes of Delta-filtered
modules. In particular, we show that these extensions can grow arbitrarily
large.


title:
What are scientific leaders? The introduction of a normalized impact
  factor

abstract:
  We define a normalized impact factor suitable to assess in a simple way both
the strength of scientific communities and the research influence of
individuals. We define those ones with $NIF \geq 1$ as being scientific leaders
since they would influence their peers at least as much as they are influenced
by them. The NIF is distinguished because (a) this has a clear and universal
meaning being applicable with equal efficiency to individuals belonging to
scientific communities with quite different publication and citation traditions
and (b) this is robust against self-citation expedient. This is eventually
applied to a community derived from the list of outstanding referees recognized
by the American Physical Society in 2008.


title:
Dependence of S-Process Nucleosynthesis in Massive Stars on Triple-Alpha
  and 12C(a,g)16O Reaction Rate Uncertainties

abstract:
  We have studied the sensitivity of s-process nucleosynthesis in massive stars
to +/- 2 sigma variations in the rates of the triple alpha and 12C(a,g)16O
reactions. We simulated the evolution of massive stars from H-burning through
Fe-core collapse, followed by a supernova explosion. We found that: the
production factors of s-process nuclides between 58Fe and 96Zr change strongly
with changes in the He burning reaction rates; using the Lodders (2003) solar
abundances rather than those of Anders and Grevesse (1989) reduces s-process
nucleosynthesis; later burning phases beyond core He burning and the shell C
burning have a significant effect on post-explosive production factors. We also
discuss the implications of the uncertainties in the helium burning rates for
evidence of a new primary neutron capture process (LEPP) in massive stars.


title: Millimeter interferometry of W3 IRS5: A Trapezium in the making

abstract:
  Although most young massive stars appear to be part of multiple systems, it
is poorly understood how this multiplicity influences the formation of massive
stars. The high-mass star-forming region W3 IRS5 is a prime example of a young
massive cluster where the cluster center is resolved into multiple subsources
at cm and infrared wavelengths, a potential proto-Trapezium system. The region
W3 IRS5 was mapped with the PdBI at 1.4mm and 3.4mm in the AB configurations,
observing shock-tracing SiO and SO_2 emission. In the continuum we detect five
sources, one of them for the first time, while counterparts were detected in
the NIR, MIR or at radio wavelengths for the remaining four sources. Three of
the detected sources are within the inner 2100AU, where the protostellar number
density exceeds 10^6 protostars pc^-3 assuming spherical symmetry. Lower limits
for the circumstellar masses of the detected sources were calculated, although
they were strongly affected by the spatial filtering of the interferometer.
However, the projected separations of the sources ranging between ~750 and
~4700AU indicate a multiple, Trapezium-like system. We detected five molecular
outflows in SiO, two of them nearly in the line of sight direction, which
allowed us to see the collapsing protostars in the NIR through the cavities
carved by the outflows. The SO_2 velocity structure indicates a rotating, bound
system, and we find tentative signatures of converging flows as predicted by
the gravoturbulent star formation and converging flow theories. The obtained
data strongly indicate that the clustered environment has a major influence on
the formation of high-mass stars; however, our data do not clearly allow us to
distinguish whether the ongoing star-forming process follows a monolithic
collapse or a competitive accretion mechanism.


title: Modelling radiation damage to ESA's Gaia satellite CCDs

abstract:
  The Gaia satellite is a high-precision astrometry, photometry and
spectroscopic ESA cornerstone mission, currently scheduled for launch in late
2011. Its primary science drivers are the composition, formation and evolution
of the Galaxy. Gaia will achieve its scientific requirements with detailed
calibration and correction for radiation damage. Microscopic models of Gaia's
CCDs are being developed to simulate the charge trapping effect of radiation
damage, which causes charge transfer inefficiency. The key to calculating the
probability of a photoelectron being captured by a trap is the 3D electron
density within each CCD pixel. However, this has not been physically modelled
for Gaia CCD pixels. In this paper, the first of a series, we motivate the need
for such specialised 3D device modelling and outline how its future results
will fit into Gaia's overall radiation calibration strategy.


title:
Chaos synchronization in a hyperbolic dynamical system with long-range
  interactions

abstract:
  We show that the threshold of complete synchronization in a lattice of
coupled non-smooth chaotic maps is determined by linear stability along the
directions transversal to the synchronization subspace. As a result, the
numerically determined synchronization threshold agree with the analytical
results previously obtained [C. Anteneodo et al., Phys. Rev. E 68, 045202(R)
(2003)] for this class of systems. We present both careful numerical
experiments and a rigorous mathematical explanation confirming this fact,
allowing for a generalization involving hyperbolic coupled map lattices.


title: Correlation Functions of Winding Strings in AdS_3

abstract:
  We review certain results for amplitudes of spectral flowed operators in
string theory on AdS_3. We present the modified Knizhnik-Zamolodchikov and null
vector equations to be satisfied by correlators including w=1 operators. We
then discuss the three point function of two w=1 and one w=0 operators in the
x-basis, and perform a consistency check on the definition of the w=1 operator.
We finally exhibit the steps in the calculation of the winding conserving four
point functions for operators in arbitrary spectral flowed sectors, both in the
m- and x-basis, under the only assumption that at least one of the operators is
in the spectral flowed image of the highest weight discrete representation.


title:
Search for High-Mass Resonances Decaying into Leptons of Different
  Flavor ($e\mu$, $e\tau$, $\mu\tau$)

abstract:
  We present a search for high-mass resonances decaying into two leptons of
different flavor: $e\mu$, $e\tau$ and $\mu\tau$. These resonances are predicted
by several models for Physics Beyond the Standard Model, such as
R-parity-violating MSSM. The search is based on 1 ${\rm fb^{-1}}$ of Tevatron
Run II data collected with the CDF detector at $\sqrt{s}$ = 1.96 TeV in proton
anti-proton collisions.


title:
Quasinormal modes of plane-symmetric black holes according to the
  AdS/CFT correspondence

abstract:
  The electromagnetic and gravitational quasinormal spectra of
$(3+1)$-dimensional plane-symmetric anti-de Sitter black holes are analyzed in
the context of the AdS/CFT correspondence. According to such a correspondence,
the electromagnetic and gravitational quasinormal frequencies of these black
holes are associated respectively to the poles of retarded correlation
functions of $R$-symmetry currents and stress-energy tensor in the
holographically dual conformal field theory: the $(2+1)$-dimensional
$\mathcal{N}=8$ super-Yang-Mills theory. The connection between AdS black holes
and the corresponding field theory is used to unambiguously fix the boundary
conditions that enter the proper definition of quasinormal modes. Such a
procedure also helps one to decide, among the various different possibilities,
what are the appropriate gauge-invariant quantities one should use in order to
correctly describe the electromagnetic and gravitational blackhole
perturbations. These choices imply in different dispersion relations for the
quasinormal modes when compared to some of the results in the literature. In
particular, the long-distance, low-frequency limit of dispersion relations
presents the characteristic hydrodynamic behavior of a conformal field theory
with the presence of diffusion, shear, and sound wave modes. There is also a
family of purely damped electromagnetic modes which tend to the bosonic
Matsubara frequencies in the long-wavelength regime.


title:
Tropical Algebraic Geometry in Maple, a preprocessing algorithm for
  finding common factors to multivariate polynomials with approximate
  coefficients

abstract:
  Finding a common factor of two multivariate polynomials with approximate
coefficients is a problem in symbolic-numeric computing. Taking a tropical view
on this problem leads to efficient preprocessing techniques, applying
polyhedral methods on the exact exponents with numerical techniques on the
approximate coefficients. With Maple we will illustrate our use of tropical
algebraic geometry.


title: Reversible-equivariant systems and matricial equations

abstract:
  This paper uses tools in group theory and symbolic computing to give a
classification of the representations of finite groups with order lower than 9
that can be derived from the study of local reversible-equivariant vector
fields in $\rn{4}$. The results are obtained by solving algebraically matricial
equations. In particular, we exhibit the involutions used in a local study of
reversible-equivariant vector fields. Based on such approach we present, for
each element in this class, a simplified Belitiskii normal form.


title: Affine buildings for dihedral groups

abstract:
  We construct rank 2 thick nondiscrete affine buildings associated with an
arbitrary finite dihedral group.


title:
Esscher transform and the duality principle for multidimensional
  semimartingales

abstract:
  The duality principle in option pricing aims at simplifying valuation
problems that depend on several variables by associating them to the
corresponding dual option pricing problem. Here, we analyze the duality
principle for options that depend on several assets. The asset price processes
are driven by general semimartingales, and the dual measures are constructed
via an Esscher transformation. As an application, we can relate swap and quanto
options to standard call and put options. Explicit calculations for jump models
are also provided.


title: Non-Equilibrium Dynamics of Single polymer Adsorption to Solid Surfaces

abstract:
  Adsorption of polymers to surfaces is crucial for understanding many
fundamental processes in nature. Recent experimental studies indicate that the
adsorption dynamics is dominated by non-equilibrium effects. We investigate the
adsorption of a single polymer of length $N$ to a planar solid surface in the
absence of hydrodynamic interactions. We find that for weak adsorption energies
the adsorption time scales $ \sim N^{(1+2\nu)/(1+\nu)}$, where $\nu$ is the
Flory exponent for the polymer. We argue that in this regime the single chain
adsorption is closely related to a field-driven polymer translocation through
narrow pores. Surprisingly, for high adsorption energies the adsorption time
becomes longer, as it scales $\sim N^{(1+\nu)}$, which is explained by strong
stretching of the unadsorbed part of the polymer close to the adsorbing
surface. These two dynamic regimes are separated by an energy scale that is
characterised by non-equilibrium contributions during the adsorption process.


title: PYTHIA 8 Status Report

abstract:
  Pythia 8, the C++ rewrite of the commonly-used Pythia event generator, is now
available in a first full-fledged version 8.1. The older Pythia 6.4 generator
in Fortran 77 is still maintained, for now, but users are strongly recommended
to try out and move to the new version as soon as feasible.


title: Towards a spin foam model description of black hole entropy

abstract:
  We propose a way to describe the origin of black hole entropy in the spin
foam models of quantum gravity. This stimulates a new way to study the relation
of spin foam models and loop quantum gravity.


title: Branes and Quantization

abstract:
  The problem of quantizing a symplectic manifold (M,\omega) can be formulated
in terms of the A-model of a complexification of M. This leads to an
interesting new perspective on quantization. From this point of view, the
Hilbert space obtained by quantization of (M,\omega) is the space of (Bcc,B')
strings, where Bcc and B' are two A-branes; B' is an ordinary Lagrangian
A-brane, and Bcc is a space-filling coisotropic A-brane. B' is supported on M,
and the choice of \omega is encoded in the choice of Bcc. As an example, we
describe from this point of view the representations of the group SL(2,R).
Another application is to Chern-Simons gauge theory.


title:
On Bounded Approximate Identities and Existence of Dense Ideals in Real
  Locally C*- and Locally JB-Algebras

abstract:
  It has been established by Inoue that a complex locally C*-algebra with a
dense ideal posesses a bounded approximate identity which belonges to that
ideal. It has been shown by Fritzsche that if a unital complex locally
C*-algebra has an unbounded element then it also has a dense one-sided ideal.
In the present paper we obtain analogues of the aforementioned results of Inoue
and Fritzsche for real locally C*-algebras (projective limits of projective
families of real C*-algebras), and for locally JB-algebras (projective limits
of projective families of JB-algebras).