title:
Utilization of photon orbital angular momentum in the low-frequency
  radio domain

abstract:
  We show numerically that vector antenna arrays can generate radio beams which
exhibit spin and orbital angular momentum characteristics similar to those of
helical Laguerre-Gauss laser beams in paraxial optics. For low frequencies (< 1
GHz), digital techniques can be used to coherently measure the instantaneous,
local field vectors and to manipulate them in software. This opens up for new
types of experiments that go beyond those currently possible to perform in
optics, for information-rich radio physics applications such as radio
astronomy, and for novel wireless communication concepts.


title: Artificial Intelligence for Conflict Management

abstract:
  Militarised conflict is one of the risks that have a significant impact on
society. Militarised Interstate Dispute (MID) is defined as an outcome of
interstate interactions, which result on either peace or conflict. Effective
prediction of the possibility of conflict between states is an important
decision support tool for policy makers. In a previous research, neural
networks (NNs) have been implemented to predict the MID. Support Vector
Machines (SVMs) have proven to be very good prediction techniques and are
introduced for the prediction of MIDs in this study and compared to neural
networks. The results show that SVMs predict MID better than NNs while NNs give
more consistent and easy to interpret sensitivity analysis than SVMs.


title: F-thresholds of hypersurfaces

abstract:
  We continue our study of F-thresholds begun in math/0607660 by an in depth
analysis of the hypersurface case. We use the D--module theoretic description
of generalized test ideals which allows us to show that in any F--finite
regular ring the F-thresholds of hypersurfaces are discrete and rational (in
math/0607660 the finite type over a field case was shown for arbitrary ideals).
Furthermore we show that any limit of F-pure thresholds of principal ideals in
bouneded dimension is again an F-pure-threshold, hence in particular the limit
is rational. The study of the set of F-pure-thresholds leads to natural analogs
of conjectures of Shokurov and Koll\'{a}r (for log canonical thresholds) in the
case of F-pure-thresholds.


title:
Dark energy generated from a (super)string effective action with higher
  order curvature corrections and a dynamical dilaton

abstract:
  We investigate the possibility of a dark energy universe emerging from an
action with higher-order string loop corrections to Einstein gravity in the
presence of a massless dilaton. These curvature corrections (up to $R^4$ order)
are different depending upon the type of (super)string model which is
considered. We find in fact that Type II, heterotic, and bosonic strings
respond differently to dark energy. A dark energy solution is shown to exist in
the case of the bosonic string, while the other two theories do not lead to
realistic dark energy universes. Detailed analysis of the dynamical stability
of the de-Sitter solution is presented for the case of a bosonic string. A
general prescription for the construction of a de-Sitter solution for the
low-energy (super)string effective action is also indicated. Beyond the
low-energy (super)string effective action, when the higher-curvature correction
coefficients depend on the dilaton, the reconstruction of the theory from the
universe expansion history is done with a corresponding prescription for the
scalar potentials.


title:
Inter comparison of the magneto transport of La2/3Ca1/3MnO3: Ag/In
  polycrystalline composites

abstract:
  In this article, we report the synthesis, magneto transport features, and
magnetization of polycrystalline La2/3Ca1/3MnO3:Agx/Inx composites with x = 0,
0.1, 0.2, 0.3 and 0.4. In case of Ag the temperature coefficient of resistance
(TCR) near ferromagnetic (FM) transition enhances significantly with addition
of Ag. The FM transition temperature (TFM) is also increased slightly with Ag
doping. Magneto-transport measurements revealed that magneto-resistance (MR) is
found to be maximum near TFM. Very sharp TCR is seen near TFM with highest
value of up to 15 % for Ag (0.4) sample, which is an order of magnitude higher
than as for pristine sample and is the best value yet reported for any
polycrystalline LCMO compound. Increased TCR, TFM and significant above room
temperature MR of La2/3Ca1/3MnO3:Agx composites is explained on the basis of
improved grains size. Interestingly the La2/3Ca1/3MnO3:Inx composites behaved
exactly in opposite way resulting in decreased TFM, and TCR compared to
pristine LCMO compound. In fact the grains morphology of LCMO:Inx composites is
seen inferior to pristine LCMO which is opposite to the LCMO:Agx case.


title: Sch\'emas en groupes et poids de Diamond-Serre

abstract:
  This note is a correction of (statement and proof of) proposition 3.3.1 of
Toby Gee's preprint intitled *On the weights of mod p Hilbert modular forms*.
The aim is to compare Galois representations arising from extensions of some
group schemes (over the ring of integers of a p-adic field) endowed with a
descent data, and extensions of some crystalline representations with given
Hodge-Tate weights. The main tool of the proof is the theory of Breuil.


title: Control of Complex Systems Using Bayesian Networks and Genetic Algorithm

abstract:
  A method based on Bayesian neural networks and genetic algorithm is proposed
to control the fermentation process. The relationship between input and output
variables is modelled using Bayesian neural network that is trained using
hybrid Monte Carlo method. A feedback loop based on genetic algorithm is used
to change input variables so that the output variables are as close to the
desired target as possible without the loss of confidence level on the
prediction that the neural network gives. The proposed procedure is found to
reduce the distance between the desired target and measured outputs
significantly.


title: Kinematic Calibration of the Orthoglide-Type Mechanisms

abstract:
  The paper proposes a novel calibration approach for the Orthoglide-type
mechanisms based on observations of the manipulator leg parallelism during
motions between the prespecified test postures. It employs a low-cost measuring
system composed of standard comparator indicators attached to the universal
magnetic stands. They are sequentially used for measuring the deviation of the
relevant leg location while the manipulator moves the TCP along the Cartesian
axes. Using the measured differences, the developed algorithm estimates the
joint offsets that are treated as the most essential parameters to be adjusted.
The sensitivity of the measurement methods and the calibration accuracy are
also studied. Experimental results are presented that demonstrate validity of
the proposed calibration technique.


title:
Variations of Gauss-Codazzi-Ricci Equations in Kaluza-Klein Reduction
  (String Theory) and Cauchy Problem (General Relativity)

abstract:
  We find a kind of variations of Gauss-Codazzi-Ricci equations suitable for
Kaluza-Klein reduction and Cauchy problem. Especially the counterpart of
extrinsic curvature tensor has antisymmetric part as well as symmetric one. If
the dependence of metric tensor on reduced dimensions is negligible it becomes
a pure antisymmetric tensor.


title:
The Design of a Novel Prismatic Drive for a Three-DOF
  Parallel-Kinematics Machine

abstract:
  The design of a novel prismatic drive is reported in this paper. This
transmission is based on Slide-O-Cam, a cam mechanism with multiple rollers
mounted on a common translating follower. The design of Slide-O-Cam was
reported elsewhere. This drive thus provides pure-rolling motion, thereby
reducing the friction of rack-and-pinions and linear drives. Such properties
can be used to design new transmissions for parallel-kinematics machines. In
this paper, this transmission is optimized to replace ball-screws in
Orthoglide, a three-DOF parallel robot optimized for machining applications.


title: Calibration of quasi-isotropic parallel kinematic Machines: Orthoglide

abstract:
  The paper proposes a novel approach for the geometrical model calibration of
quasi-isotropic parallel kinematic mechanisms of the Orthoglide family. It is
based on the observations of the manipulator leg parallelism during motions
between the specific test postures and employs a low-cost measuring system
composed of standard comparator indicators attached to the universal magnetic
stands. They are sequentially used for measuring the deviation of the relevant
leg location while the manipulator moves the TCP along the Cartesian axes.
Using the measured differences, the developed algorithm estimates the joint
offsets and the leg lengths that are treated as the most essential parameters.
Validity of the proposed calibration technique is confirmed by the experimental
results.


title:
Analysis and Design of an Organic High Speed Digital Electro-Optic
  Switch

abstract:
  We have analyzed and designed an organic high speed digital optical switch
(DOS) based on transverse electro-optic effect. In analysis section, we
proposed a quantum photonic model (QPM) to explain linear electro-optic (EO)
effect. This model interpret this effect by photon-electron interaction in
attosecond regime. We simulate applied electric field on molecule and crystal
by Monte-Carlo method in time domain. We show how a waveguide response to an
optical signal with different wavelengths when a transverse electric field
applied to the waveguide. In design section, we configure conceptually a 2 * 2
EO switch with full adiabatic coupler. In this DOS, we use a rib waveguides
that its core has been constructed from NPP crystal. This switch is smaller at
least to one-half of similar DOS in dimensions.


title: A simple solution to Ulam's liar game with one lie

abstract:
  Ulam asked for the maximum number of questions required to determine an
integer between one and one million by asking questions whose answer is `Yes'
or `No' and where one untruthful answer is allowed. Pelc showed that the number
of questions required is 25. Here we give a simple proof of this result.


title: Ground state of a confined Yukawa plasma including correlation effects

abstract:
  The ground state of an externally confined one-component Yukawa plasma is
derived analytically using the local density approximation (LDA). In
particular, the radial density profile is computed. The results are compared
with the recently obtained mean-field (MF) density profile
\cite{henning.pre06}. While the MF results are more accurate for weak
screening, LDA with correlations included yields the proper description for
large screening. By comparison with first-principle simulations for
three-dimensional spherical Yukawa crystals we demonstrate that both
approximations complement each other. Together they accurately describe the
density profile in the full range of screening parameters.


title: Markov properties in presence of measurement noise

abstract:
  Recently, several powerful tools for the reconstruction of stochastic
differential equations from measured data sets have been proposed [e.g. Siegert
et al., Physics Letters A 243, 275 (1998); Hurn et al., Journal of Time Series
Analysis 24, 45 (2003)]. Efficient application of the methods, however,
generally requires Markov properties to be fulfilled. This constraint typically
seems to be violated on small scales, which frequently is attributed to
physical effects. On the other hand, measurement noise such as uncorrelated
measurement and discretization errors has large impacts on the statistics of
measurements on small scales. We demonstrate, that the presence of measurement
noise, likewise, spoils Markov properties of an underlying Markov processes.
This fact is promising for the further development of techniques for the
reconstruction of stochastic processes from measured data, since limitations at
small scales might stem from artificial noise sources rather than from
intrinsic properties of the dynamics of the underlying process. Measurement
noise, however, can be controlled much better than the intrinsic dynamics of
the underlying process.


title: Impact of Ion Clearing Electrodes on Beam Dynamics in DAFNE

abstract:
  Presently clearing electrodes are being considered as a possible cure of
e-cloud driven problems in existing and future colliders. 'Invisible'
electrodes, made of a thin highly resistive layer pasted on a dielectric plate,
have been proposed as one of design solutions for the e-cloud clearing. For the
first time such electrodes were successfully used in the electron-positron
accumulator (EPA) of LEP. Similar electrodes had been using for a long time for
ion clearing purposes in the DAFNE electron ring. Theoretical considerations
and experimental measurements at DAFNE have revealed a substantial contribution
of the ion clearing electrodes (ICE) to the machine broad-band impedance giving
rise to several harmful effects degrading the collider performance. In this
paper we discuss the impact of the electrodes on DAFNE beam dynamics, show the
results of ICE wake field and impedance calculations and compare them with
available experimental data. We also describe the procedure of ICE removal from
the wiggler sections of the electron ring that has resulted in remarkable
improvements in terms of beam dynamics and geometric luminosity.


title: Fluctuations of eigenvalues and second order Poincar\'e inequalities

abstract:
  Linear statistics of eigenvalues in many familiar classes of random matrices
are known to obey gaussian central limit theorems. The proofs of such results
are usually rather difficult, involving hard computations specific to the model
in question. In this article we attempt to formulate a unified technique for
deriving such results via relatively soft arguments. In the process, we
introduce a notion of `second order Poincar\'e inequalities': just as ordinary
Poincar\'e inequalities give variance bounds, second order Poincar\'e
inequalities give central limit theorems. The proof of the main result employs
Stein's method of normal approximation. A number of examples are worked out,
some of which are new. One of the new results is a CLT for the spectrum of
gaussian Toeplitz matrices.


title:
Hawking radiation from the Schwarzschild black hole with a global
  monopole via gravitational anomaly

abstract:
  Hawking flux from the Schwarzschild black hole with a global monopole is
obtained by using Robinson and Wilczek's method. Adopting a dimension reduction
technique, the effective quantum field in the (3+1)--dimensional global
monopole background can be described by an infinite collection of the
(1+1)--dimensional massless fields if neglecting the ingoing modes near the
horizon, where the gravitational anomaly can be cancelled by the
(1+1)--dimensional black body radiation at the Hawking temperature.


title:
A semi-classical field method for the equilibrium Bose gas and
  application to thermal vortices in two dimensions

abstract:
  We develop a semi-classical field method for the study of the weakly
interacting Bose gas at finite temperature, which, contrarily to the usual
classical field model, does not suffer from an ultraviolet cut-off dependence.
We apply the method to the study of thermal vortices in spatially homogeneous,
two-dimensional systems. We present numerical results for the vortex density
and the vortex pair distribution function. Insight in the physics of the system
is obtained by comparing the numerical results with the predictions of simple
analytical models. In particular, we calculate the activation energy required
to form a vortex pair at low temperature.


title:
Rate Adaptation for Cognitive Radio under Interference from Primary
  Spectrum User

abstract:
  A cognitive radio can operate as a secondary system in a given spectrum. This
operation should use limited power in order not to disturb the communication by
primary spectrum user. Under such conditions, in this paper we investigate how
to maximize the spectral efficiency in the secondary system. A secondary
receiver observes a multiple access channel of two users, the secondary and the
primary transmitter, respectively. We show that, for spectrally-efficient
operation, the secondary system should apply Opportunistic Interference
Cancellation (OIC). With OIC, the secondary system decodes the primary signal
when such an opportunity is created by the primary rate and the power received
from the primary system. For such an operation, we derive the achievable data
rate in the secondary system. When the primary signal is decodable, we devise a
method, based on superposition coding, by which the secondary system can
achieve the maximal possible rate. Finally, we investigate the power allocation
in the secondary system when multiple channels are used. We show that the
optimal power allocation with OIC can be achieved through intercepted
water-filling instead of the conventional water-filling. The results show a
significant gain for the rate achieved through an opportunistic interference
cancellation.


title: Massless interacting particles

abstract:
  We show that classical electrodynamics of massless charged particles and the
Yang--Mills theory of massless quarks do not experience rearranging their
initial degrees of freedom into dressed particles and radiation. Massless
particles do not radiate. We consider a version of the direct interparticle
action theory for these systems following the general strategy of Wheeler and
Feynman.


title: Diluted Graphene Antiferromagnet

abstract:
  We study RKKY interactions between local magnetic moments for both doped and
undoped graphene. We find in both cases that the interactions are primarily
ferromagnetic for moments on the same sublattice, and antiferromagnetic for
moments on opposite sublattices. This suggests that at sufficiently low
temperatures dilute magnetic moments embedded in graphene can order into a
state analogous to that of a dilute antiferromagnet. We find that in the
undoped case one expects no net magnetic moment, and demonstrate numerically
that this effect generalizes to ribbons where the magnetic response is
strongest at the edge, suggesting the possibility of an unusual spin-transfer
device. For doped graphene we find that moments at definite lattice sites
interact over longer distances than those placed in interstitial sites of the
lattice ($1/R^2$ vs. $1/R^3$) because the former support a Kohn anomaly that is
suppressed in the latter due to the absence of backscattering.


title:
Direct calculation of interfacial tensions from computer simulation:
  Results for freely jointed tangent hard sphere chains

abstract:
  We develop a methodology for the calculation of surface free energies based
on the probability distribution of a wandering interface. Using a simple
extension of the NpT sampling, we allow the interface area to randomly probe
the available space and evaluate the surface free energy from histogram
analysis and the corresponding average. The method is suitable for studying
systems with either continuous or discontinuous potentials, as it does not
require explicit evaluation of the virial. The proposed algorithm is compared
with known results for the surface tension of Lennard--Jones and Square Well
fluid, as well as for the interface tension of a bead--spring polymer model and
good agreement is found. We also calculate interfacial tensions of freely
jointed tangent hard sphere chains on athermal walls for a wide range of chain
lengths and densities. The results are compared with three different
theoretical approaches, Scaled Particle Theory, the Yu and Wu density
functional theory and an analytical approximation based on the latter approach.
Whereas SPT only yields qualitative results, the last two approaches are found
to yield very good agreement with simulations.


title:
The outburst of the eruptive young star OO Serpentis between 1995 and
  2006

abstract:
  OO Serpentis is a deeply embedded pre-main sequence star that went into
outburst in 1995 and gradually faded afterwards. Its eruption resembled the
well-known FU Orionis-type or EX Lupi-type outbursts. Since very few such
events have ever been documented at infrared wavelengths, our aim is to study
the temporal evolution of OO Ser in the infrared. OO Ser was monitored with the
Infrared Space Observatory starting 4 months after peak brightness and covering
20 months. In 2004-2006 we again observed OO Ser from the ground and
complemented this dataset with archival Spitzer obsevations also from 2004. We
analysed these data with special attention to source confusion and constructed
light curves at 10 different wavelengths as well as spectral energy
distributions. The outburst caused brightening in the whole infrared regime.
According to the infrared light curves, OO Ser started a wavelength-independent
fading after peak brightness. Later the flux decay became slower but stayed
wavelength-independent. The fading is still ongoing, and current fading rates
indicate that OO Ser will not return to quiescent state before 2011. The
outburst timescale of OO Ser seems to be shorter than that of FUors, but longer
than that of EXors. The outburst timescale and the moderate luminosity suggest
that OO Ser is different from both FUors and EXors, and shows similarities to
the recently erupted young star V1647 Ori. Based on its spectral energy
distribution and bolometric temperature, OO Ser seems to be an early class I
object, with an age of < 10^5 yr. The object is probably surrounded by an
accretion disc and a dense envelope. Due to the shorter outburst timescales,
the viscosity in the circumstellar disc of OO Ser is probably an order of
magnitude higher than usual for FUors.


title: Nontrivial quantum effects in biology: A skeptical physicists' view

abstract:
  Invited contribution to "Quantum Aspects of Life", D. Abbott Ed. (World
Scientific, Singapore, 2007).


title: Pseudo-Complex Field Theory

abstract:
  A new formulation of field theory is presented, based on a pseudo-complex
description. An extended group structure is introduced, implying a minimal
scalar length, rendering the theory regularized a la Pauli-Villars. Cross
sections are calculated for the scattering of an electron at an external
Coulomb field and the Compton scattering. Deviations due to a smallest scalar
length are determined. The theory also permits a modification of the minimal
coupling scheme, resulting in a generalized dispersion relation. A shift of the
Greisen-Zatsepin-Kuzmin-limit (GZK) of the cosmic ray spectrum is the
consequence.


title: Early Time Dynamics in Heavy Ion Collisions from AdS/CFT Correspondence

abstract:
  We study the matter produced in heavy ion collisions assuming that this
matter is strongly interacting and employing AdS/CFT correspondence to
investigate its dynamics. At late proper times we show that Bjorken
hydrodynamics solution, obtained recently by Janik and Peschanski using
gauge-gravity duality [hep-th/0512162], can be singled out by simply requiring
that the metric tensor is a real and single-valued function of the coordinates
everywhere in the bulk, without imposing any constraints on the curvature
invariant. At early proper times we use similar strategy to show that the
energy density approaches a constant as proper time goes to zero. We therefore
demonstrate that the strong coupling dynamics incorporates the isotropization
transition in heavy ion collisions. By matching our early-time regime with the
late-time one of Janik and Peschanski we estimate the isotropization time at
RHIC to be approximately 0.3 fm/c, in good agreement with results of
hydrodynamic simulations.


title: Statistical minimax approach of the Hausdorff moment problem

abstract:
  The purpose of this paper is to study the problem of estimating a compactly
supported density of probability from noisy observations of its moments. In
fact, we provide a statistical approach to the famous Hausdorff classical
moment problem. We prove an upper bound and a lower bound on the rate of
convergence of the mean squared error showing that the considered estimator
attains minimax rate over the corresponding smoothness classes.


title:
Radiation trapping in 1D using the Markov chain formalism: A
  computational physics project

abstract:
  A computational model study for complete frequency redistribution linear
incoherent two-level atomic radiation trapping in optically dense media using
the multiple scattering representation is presented. This model study discuss
at length the influence of the spectral distributions, overall opacity and
emission quantum yield to trapping distorted ensemble quantities stressing
physical insight and with a non-specialist audience in mind. Macroscopic
reemission yield, lifetime, steady state spectra and spatial distributions are
calculated as a function of intrinsic emission yield, opacity and external
excitation mode for Doppler, Lorentz and Voigt lineshapes. The work could
constitute the basis for a final undergraduate or beginning graduate project in
computational physics instruction and implements the analytical developments of
the previous instalment of this contribution.


title:
The neighborhood of the Standard Model: mixing angles and quark-lepton
  complementarity for three generations of non-degenerate coupled fermions

abstract:
  We investigate the potential (small) deviations from the unitarity of the
mixing matrix that are expected to occur, because of mass splittings, in the
Quantum Field Theory of non-degenerate coupled systems. We extend our previous
analysis concerning mixing angles, which led to a precise determination of the
Cabibbo angle, to the case of three generations of fermions. We show that the
same condition for neutral currents of mass eigenstates, i.e. that universality
of diagonal currents is violated with the same strength as the absence of
non-diagonal ones, is satisfied: on one hand, by the three CKM mixing angles
with a precision higher than the experimental uncertainty; on the other hand,
by a neutrino-like mixing pattern in which theta_{23} is maximal, and tan (2
theta_{12})=2. This last pattern turns out to satisfy exactly the "quark-lepton
complementarity condition" theta_c + theta_{12}= pi/4. Moreover, among all
solutions, two values for the third neutrino mixing angle arise which satisfy
the bound sin^2(theta_{13}) < 0.1: theta_{13} = +/- 5.7 10^{-3} and theta_{13}
= +/- 0.2717. The so-called "Neighborhood of the Standard Model" is thus
confirmed to exhibit special patterns which presumably originate in physics
"Beyond the Standard Model".


title: Geometry of non-supersymmetric three-charge bound states

abstract:
  We study the smooth non-supersymmetric three-charge microstates of Jejjala,
Madden, Ross and Titchener [hep-th/0504181] using Kaluza-Klein reductions of
the solutions to five and four dimensions. Our aim is to improve our
understanding of the relation between these non-supersymmetric solutions and
the well-studied supersymmetric cases. We find some surprising qualitative
differences. In the five-dimensional description, the solution has orbifold
fixed points which break supersymmetry locally, so the geometries cannot be
thought of as made up of separate half-BPS centers. In the four-dimensional
description, the two singularities in the geometry are connected by a conical
singularity, which makes it impossible to treat them independently and assign
unambiguous brane charges to these centers.


title:
Stray-fields-based magnetoresistance mechanism in Ni80Fe20-Nb-Ni80Fe20
  trilayers

abstract:
  We report on the transport and magnetic properties of hybrid trilayers and
bilayers that consist of low spin-polarized Ni80Fe20 exhibiting in-plane but no
uniaxial anisotropy and low-Tc Nb. We reveal a magnetoresistance effect that is
pronounced. In our trilayers the magnetoresistance exhibits an increase of two
orders of magnitude when the superconducting state is reached: from the
conventional normal-state values 0.6 % it goes up to 1000 % for temperatures
below Tc. In contrast, in the bilayers the effect is only minor since from 3%
in the normal state increases only to 70 % for temperatures below Tc.
Magnetization data of both the longitudinal and transverse magnetic components
are presented. Most importantly, we present data not only for the normal state
of Nb but also in its superconducting state. Strikingly, these data show that
below its Tc SC the Nb interlayer under the influence of the outer Ni80Fe20
layers attains a magnetization component transverse to the external field. By
comparing the transport and magnetization data we propose a candidate mechanism
that could motivate the pronounced magnetoresistance effect observed in the
trilayers. Adequate magnetostatic coupling of the outer Ni80Fe20 layers is
motivated by stray fields that emerge naturally in their whole surface due to
the multidomain magnetic structure that they attain near coercivity. Atomic
force microscopy is employed in order to examine the possibility that such
magnetostatic coupling could be promoted by interface roughness. Referring to
the bilayers, although out-of-plane rotation of the magnetization of the single
Ni80Fe20 layer is still observed, in these structures magnetostatic coupling
does not occur due to the absence of a second Ni80Fe20 one so that the observed
magnetoresistance peaks are only modest.


title: Quark-nova explosion inside a collapsar: application to Gamma Ray Bursts

abstract:
  If a quark-nova occurs inside a collapsar, the interaction between the
quark-nova ejecta (relativistic iron-rich chunks) and the collapsar envelope,
leads to features indicative of those observed in Gamma Ray Bursts. The
quark-nova ejecta collides with the stellar envelope creating an outward moving
cap
  (Gamma ~ 1-10) above the polar funnel. Prompt gamma-ray burst emission from
internal shocks in relativistic jets (following accretion onto the quark star)
become visible after the cap becomes optically thin. Model features include:
(i) precursor activity (optical, X-ray, gamma-ray), (ii) prompt gamma-ray
emission, and (iii) afterglow emission. We discuss SN-less long duration GRBs,
short hard GRBs (including association and non-association with star forming
regions), dark GRBs, the energetic X-ray flares detected in Swift GRBs, and the
near-simultaneous optical and gamma-ray prompt emission observed in GRBs in the
context of our model.


title: Percolation in a Class of Band Structured Random Matrices

abstract:
  We define a class of random matrix ensembles that pertain to random looped
polymers. Such random looped polymers are a possible model for bio-polymers
such as chromatin in the cell nucleus. It is shown that the distribution of the
largest eigenvalue $\lambda_{max}$ depends on a percolation transition in the
entries of the random matrices. Below the percolation threshold the
distribution is multi-peaked and changes above the threshold to the Tracy-Widom
distribution. We also show that the distribution of the eigenvalues is neither
of the Wigner form nor gaussian.


title:
Stochastic Absorption of the Light of Background Sources due to
  Intergalactic Neutral Hydrogen I. Testing different line-number evolution
  models via the cosmic flux decrement

abstract:
  [Abridged] We test the accuracy of different models of the attenuation of
light due to resonant scattering by intergalactic neutral hydrogen by comparing
their predictions of the evolution of the mean cosmic flux decrement, D_A, to
measurements of this quantity based on observations. To this end, we use data
available in the literature and our own measurements of the cosmic flux
decrement for 25 quasars in the redshift range 2.71 < z < 5.41 taken from the
SDSS Data Release 5. In order to perform the measurements of D_A, we fit a
power-law to the continuum redward of the Lya emission line, and extrapolate
this fit to region blueward of it, where the flux is severely affected by
absorption due to intervening HI absorbers. We compute, using numerical
simulations, the redshift evolution of D_A accounting for the presence of Lya
Forest absorbers and Lyman limit systems randomly distributed along the
line-of-sight, and compute its intrinsic scatter at the 1-, 2-, and 3-sigma
level due to fluctuations in the absorber properties (column density, Doppler
parameter, redshift) along different lines-of-sight. The numerical simulations
consist of Monte Carlo realizations of distributions of the absorber properties
constrained from observations. The results from the models considered here
confirm our theoretical expectation that the distribution of D_A at any given
redshift be well described by a lognormal distribution function. This implies
that the effective optical depth, usually defined as the negative logarithm of
the average flux, 1 - D_A, is very accurately Gaussian distributed, in contrast
to previous studies. This result is independent to the form of the input
distribution functions, and rather insensitive to the presence of high-column
density absorbers, such as the Lyman limit systems.


title: Crown theory for the upper halfplane

abstract: I exemplify part of my recent work on the upper halfplane.


title: Evolving Symbolic Controllers

abstract:
  The idea of symbolic controllers tries to bridge the gap between the top-down
manual design of the controller architecture, as advocated in Brooks'
subsumption architecture, and the bottom-up designer-free approach that is now
standard within the Evolutionary Robotics community. The designer provides a
set of elementary behavior, and evolution is given the goal of assembling them
to solve complex tasks. Two experiments are presented, demonstrating the
efficiency and showing the recursiveness of this approach. In particular, the
sensitivity with respect to the proposed elementary behaviors, and the
robustness w.r.t. generalization of the resulting controllers are studied in
detail.


title: Microlocalization of rational Cherednik algebras

abstract:
  We construct a microlocalization of the rational Cherednik algebras $H$ of
type $S_n$. This is achieved by a quantization of the Hilbert scheme
$\Hilb^n\C^2$ of $n$ points in $\C^2$. We then prove the equivalence of the
category of $H$-modules and the one of modules over its microlocalization under
certain conditions on the parameter.


title:
The Position of High Frequency Waves with Respect to the Granulation
  Pattern

abstract:
  High frequency velocity oscillations were observed in the spectral lines Fe I
543.45nm and 543.29nm, using 2D spectroscopy with a Fabry- Perot and speckle
reconstruction, at the VTT in Tenerife. We investigate the radial component of
waves with frequencies in the range 8 - 22mHz in the internetwork, network and
a pore. We find that the occurrence of waves do not show any preference on
location and are equally distributed over down-flows and up-flows, regardless
of the activity of the observed area in the line of Fe I 543.45nm. The waves
observed in the lower formed line of Fe I 543.29nm seem to appear
preferentially over down-flows.


title: Stochastic interacting particle systems out of equilibrium

abstract:
  This paper provides an introduction to some stochastic models of lattice
gases out of equilibrium and a discussion of results of various kinds obtained
in recent years. Although these models are different in their microscopic
features, a unified picture is emerging at the macroscopic level, applicable,
in our view, to real phenomena where diffusion is the dominating physical
mechanism. We rely mainly on an approach developed by the authors based on the
study of dynamical large fluctuations in stationary states of open systems. The
outcome of this approach is a theory connecting the non equilibrium
thermodynamics to the transport coefficients via a variational principle. This
leads ultimately to a functional derivative equation of Hamilton-Jacobi type
for the non equilibrium free energy in which local thermodynamic variables are
the independent arguments. In the first part of the paper we give a detailed
introduction to the microscopic dynamics considered, while the second part,
devoted to the macroscopic properties, illustrates many consequences of the
Hamilton-Jacobi equation. In both parts several novelties are included.


title: L'Univers en expansion et probl\`emes d'\'energie

abstract:
  In this paper we first construct a mathematical model for the Universe
expansion that started up with the original Big Bang. Next, we discuss the
problematic of the mechanical and physical laws invariance regarding the
spatial frame exchanges. We then prove the (theoretical) existence of a
variable metric $g_t$, depending on time and satisfying to a simplified
Einstein equation, so that all free ordinary trajectories are geodesics. This
is done by considering the classical Galileo-Newtonian space and time relation,
by using generalized Newtonian principles and adding the approved physical new
ones (as covariance principle, Mach principle, the Einstein equivalence
principle ...) in order to establish a new cosmological model of the dynamical
Universe as being $(U(t))_{t\geq 0}=(B_e(O,t),g_t)_{t\geq 0}$, where $B_e(O,t)$
is the Euclidean ball of radius $t$ in $\mathbb R^3$. The cosmological metric
$g_t$ is totally determined, at time $t$, by the mass energy distribution
$E_t(X)$ on $B_e(O,t)$. We study also the black holes phenomenon and we prove
that the total and global cosmological energy distribution $E_t(X)$ satisfies
to the wave equation whose solutions are characterized by pseudo-frequencies
depending on time and related to the spectrum of the Dirichlet problem on the
unit ball $B_e(O,1)$ for the Laplace-Beltrami operator -$\Delta$. Our model is
consistent in the sense that all Newtonian and classical physical laws are
valid as particular cases in classical situations. Then, we show that all basic
results of Modern Physics are still valid without using the second postulate of
special relativity nor the uncertainty principle.


title: IGR J17254-3257, a new bursting neutron star

abstract:
  The study of the observational properties of uncommonly long bursts from low
luminosity sources with extended decay times up to several tens of minutes is
important when investigating the transition from a hydrogen-rich bursting
regime to a pure helium regime and from helium burning to carbon burning as
predicted by current burst theories. IGR J17254-3257 is a recently discovered
X-ray burster of which only two bursts have been recorded: an ordinary short
type I X-ray burst, and a 15 min long burst. An upper limit to its distance is
estimated to about 14.5 kpc. The broad-band spectrum of the persistent emission
in the 0.3-100 keV energy band obtained using contemporaneous INTEGRAL and
XMM-Newton data indicates a bolometric flux of 1.1x10^-10 erg/cm2/s
corresponding, at the canonical distance of 8 kpc, to a luminosity about
8.4x10^35 erg/s between 0.1-100 keV, which translates to a mean accretion rate
of about 7x10^-11 solar masses per year. The low X-ray persistent luminosity of
IGR J17254-3257 seems to indicate the source may be in a state of low accretion
rate usually associated with a hard spectrum in the X-ray range. The nuclear
burning regime may be intermediate between pure He and mixed H/He burning. The
long burst is the result of the accumulation of a thick He layer, while the
short one is a prematurate H-triggered He burning burst at a slightly lower
accretion rate.


title: Persistence of a Rouse polymer chain under transverse shear flow

abstract:
  We consider a single Rouse polymer chain in two dimensions in presence of a
transverse shear flow along the $x$ direction and calculate the persistence
probability $P_0(t)$ that the $x$ coordinate of a bead in the bulk of the chain
does not return to its initial position up to time $t$. We show that the
persistence decays at late times as a power law, $P_0(t)\sim t^{-\theta}$ with
a nontrivial exponent $\theta$. The analytical estimate of $\theta=0.359...$
obtained using an independent interval approximation is in excellent agreement
with the numerical value $\theta\approx 0.360\pm 0.001$.


title: Diagonalizing the Frobenius

abstract:
  Over a Noetherian, local ring R of prime characteristic p, the Frobenius
functor F induces a diagonalizable map on certain quotients of rational
Grothendieck groups. This leads to an explicit formula for the Dutta
multiplicity, and it is shown that a weaker version of Serre's vanishing
conjecture holds if only chi(F(X)) = p^{dim R}chi(X) for all bounded complexes
X of finitely generated, projective modules with finite length homology.


title: The Tasaki-Crooks quantum fluctuation theorem

abstract:
  Starting out from the recently established quantum correlation function
expression of the characteristic function for the work performed by a force
protocol on the system [cond-mat/0703213] the quantum version of the Crooks
fluctuation theorem is shown to emerge almost immediately by the mere
application of an inverse Fourier transformation.


title: Dualities and intersection multiplicities

abstract:
  Let R be a commutative, noetherian, local ring. Topological Q-vector spaces
modelled on full subcategories of the derived category of R are constructed in
order to study intersection multiplicities.


abstract:
  An implicit numerical algorithm general relativistic hydrodynamics This
article has been replaced by arXiv:0801.1017


title: Controllable Adiabatic Manipulation of the Qubit State

abstract:
  We propose a scheme which implements a controllable change of the state of
the target spin qubit in such a way that both the control and the target spin
qubits remain in their ground states. The interaction between the two spins is
mediated by an auxiliary spin, which can transfer to its excited state. Our
scheme suggests a possible relationship between the gate and adiabatic quantum
computation.


title: Memory-built-in quantum teleportation with photonic and atomic qubits

abstract:
  The combination of quantum teleportation and quantum memory of photonic
qubits is essential for future implementations of large-scale quantum
communication and measurement-based quantum computation. Both steps have been
achieved separately in many proof-of-principle experiments, but the
demonstration of memory-built-in teleportation of photonic qubits remains an
experimental challenge. Here, we demonstrate teleportation between photonic
(flying) and atomic (stationary) qubits. In our experiment, an unknown
polarization state of a single photon is teleported over 7 m onto a remote
atomic qubit that also serves as a quantum memory. The teleported state can be
stored and successfully read out for up to 8 micro-second. Besides being of
fundamental interest, teleportation between photonic and atomic qubits with the
direct inclusion of a readable quantum memory represents a step towards an
efficient and scalable quantum network.


title:
Spatial motion of the magnetic avalanches associated to the CO-AFM to
  CD-FM transition in La$_{0.225}$Pr$\_{0.40}$Ca$\_{0.375}$MnO$\_{3}$ manganite

abstract:
  Very fast magnetic avalanches in (La, Pr)-based manganites are the signature
of a phase transition from an insulating blocked charge-ordered (CO-AFM) state
to a charge delocalized ferromagnetic (CD-FM) state. We report here the
experimental observation that this transition does not occur neither
simultaneously nor randomly in the whole sample but there is instead a spatial
propagation with a velocity of the order of tens of m/s. Our results show that
avalanches are originated in the inside of the sample, move to the outside and
occur at values of the applied magnetic field that depend on the CD-FM fraction
in the sample. Moreover, a change in the gradient of the magnetic field along
the sample shifts the point where the avalanches are ignited.


title:
A method of state-selective transfer of atoms between microtraps based
  on the Franck-Condon Principle

abstract:
  We present a method of transferring a cold atom between spatially separated
microtraps by means of a Raman transition between the ground motional states of
the two traps. The intermediate states for the Raman transition are the
vibrational levels of a third microtrap, and we determine the experimental
conditions for which the overlap of the wave functions leads to an efficient
transfer. There is a close analogy with the Franck-Condon principle in the
spectroscopy of molecules. Spin-dependent manipulation of neutral atoms in
microtraps has important applications in quantum information processing. We
also show that starting with several atoms, precisely one atom can be
transferred to the final potential well hence giving deterministic preparation
of single atoms.


title:
Towards a measurement of the two-photon decay width of the Higgs boson
  at a Photon Collider

abstract:
  A study of the measurement of the two photon decay width times the branching
ratio of a Higgs boson with the mass of 120 GeV in photon - photon collisions
is presented, assuming a gamma-gamma integrated luminosity of 80 fb^-1 in the
high energy part of the spectrum. The analysis is based on the reconstruction
of the Higgs events produced in the gamma gamma --> H process, followed by the
decay of the Higgs into a bbbar pair. A statistical error of the measurement of
the two-photon width times the branching ratio of the Higgs boson decaying into
b-quarks is found to be 2.1% for one year of data taking.


title: Quantum-like Representation of Extensive Form Games: Wine Testing Game

abstract:
  We consider an application of the mathematical formalism of quantum mechanics
(QM) outside physics, namely, to game theory. We present a simple game between
macroscopic players, say Alice and Bob (or in a more complex form - Alice, Bob
and Cecilia), which can be represented in the quantum-like (QL) way -- by using
a complex probability amplitude (game's ``wave function'') and noncommutative
operators. The crucial point is that games under consideration are so called
extensive form games. Here the order of actions of players is important, such a
game can be represented by the tree of actions. The QL probabilistic behavior
of players is a consequence of incomplete information which is available to
e.g. Bob about the previous action of Alice. In general one could not construct
a classical probability space underlying a QL-game. This can happen even in a
QL-game with two players. In a QL-game with three players Bell's inequality can
be violated. The most natural probabilistic description is given by so called
contextual probability theory completed by the frequency definition of
probability.


title: Theory of spatial mode competition in a fiber amplifier

abstract:
  Theory of monochromatic wave field amplification in a waveguide array based
on expansion of the wave field in terms of guided array modes is developed.
Equations for the expansion coefficients include cross-modal gain, which
completely changes behavior of the amplified wave field. Analysis of two-mode
amplification reveals new unusual features in characteristics of two-mode
amplifier. Instead of unlimited growth of both modes for incoherent fields, one
of the modes grows with no limit and suppresses the lower-power mode. Effects
associated with the cross-modal gain are illustrated analytically on a system
of two thin parallel planar waveguides. Conditions are found when a mode with
lower gain can become the dominant one at the output of amplifier.


title:
Extremal first Dirichlet eigenvalue of doubly connected plane domains
  and dihedral symmetry

abstract:
  We deal with the following eigenvalue optimization problem: Given a bounded
domain $D\subset \R^2$, how to place an obstacle $B$ of fixed shape within $D$
so as to maximize or minimize the fundamental eigenvalue $\lambda_1$ of the
Dirichlet Laplacian on $D\setminus B$. This means that we want to extremize the
function $\rho\mapsto \lambda_1(D\setminus \rho (B))$, where $\rho$ runs over
the set of rigid motions such that $\rho (B)\subset D$. We answer this problem
in the case where both $D$ and $B$ are invariant under the action of a dihedral
group $\mathbb{D}_n$, $n\ge2$, and where the distance from the origin to the
boundary is monotonous as a function of the argument between two axes of
symmetry. The extremal configurations correspond to the cases where the axes of
symmetry of $B$ coincide with those of $D$.


title:
Domain deformations and eigenvalues of the Dirichlet Laplacian in a
  Riemannian manifold

abstract:
  For any bounded regular domain $\Omega$ of a real analytic Riemannian
manifold $M$, we denote by $\lambda_{k}(\Omega)$ the $k$-th eigenvalue of the
Dirichlet Laplacian of $\Omega$. In this paper, we consider $\lambda_k$ and as
a functional upon the set of domains of fixed volume in $M$. We introduce and
investigate a natural notion of critical domain for this functional. In
particular, we obtain necessary and sufficient conditions for a domain to be
critical, locally minimizing or locally maximizing for $\lambda_k$. These
results rely on Hadamard type variational formulae that we establish in this
general setting.


title:
The generalized second law of thermodynamics in the accelerating
  universe

abstract:
  We show that in the accelerating universe the generalized second law of
thermodynamics holds only in the case where the enveloping surface is the
apparent horizon, but not in the case of the event horizon. The present
analysis relies on the most recent SNe Ia events, being model independent. Our
study might suggest that event horizon is not a physical boundary from the
point of view of thermodynamics.


title:
A noncommutative Bohnenblust-Spitzer identity for Rota-Baxter algebras
  solves Bogoliubov's recursion

abstract:
  The Bogoliubov recursion is a particular procedure appearing in the process
of renormalization in perturbative quantum field theory. It provides convergent
expressions for otherwise divergent integrals. We develop here a theory of
functional identities for noncommutative Rota-Baxter algebras which is shown to
encode, among others, this process in the context of Connes-Kreimer's Hopf
algebra of renormalization. Our results generalize the seminal Cartier-Rota
theory of classical Spitzer-type identities for commutative Rota-Baxter
algebras. In the classical, commutative, case, these identities can be
understood as deriving from the theory of symmetric functions. Here, we show
that an analogous property holds for noncommutative Rota-Baxter algebras. That
is, we show that functional identities in the noncommutative setting can be
derived from the theory of noncommutative symmetric functions. Lie idempotents,
and particularly the Dynkin idempotent play a crucial role in the process.
Their action on the pro-unipotent groups such as those of perturbative
renormalization is described in detail along the way.


title: Tracer diffusion in colloidal gels

abstract:
  Computer simulations were done of the mean square displacement (MSD) of
tracer particles in colloidal gels formed by diffusion or reaction limited
aggregation of hard spheres. The diffusion coefficient was found to be
determined by the volume fraction accessible to the spherical tracers
($\phi_a$) independent of the gel structure or the tracer size. In all cases,
critical slowing down was observed at $\phi_a\approx 0.03$ and was
characterized by the same scaling laws reported earlier for tracer diffusion in
a Lorentz gas. Strong heterogeneity of the MSD was observed at small $\phi_a$
and was related to the size distribution of pores.


title: RBS1423 - a new QSO with relativistic reflection from an ionised disk

abstract:
  We present the analysis and results of a 20 ks XMM-Newton observation of
RBS1423. X-ray spectral analysis is used to establish a significantly broadened
relativistic iron K-alpha line from a highly ionised disk. A QSO at z=2.262 was
considered to be the optical counterpart of this ROSAT Bright Survey X-ray
source. Based on the improved XMM-Newton source position we identified a
z=0.208 QSO as optical counterpart to RBS1423. The 0.2-12 keV X-ray luminosity
of this radio-quiet QSO is 6x10^{44} erg/s. The XMM-EPIC spectra are well
described by a power law with a significantly broadened iron K-alpha line. Disk
line models for both Schwarzschild and Kerr black holes require hydrogen-like
iron ions to fit the measured line profile. Significant ionisation of the
reflection disk is confirmed by model fits with ionised disk models, resulting
in an ionisation parameter xi~2000.


title:
Diffusion covariation and co-jumps in bidimensional asset price
  processes with stochastic volatility and infinite activity Levy jumps

abstract:
  In this paper we consider two processes driven by diffusions and jumps. The
jump components are Levy processes and they can both have finite activity and
infinite activity. Given discrete observations we estimate the covariation
between the two diffusion parts and the co-jumps. The detection of the co-jumps
allows to gain insight in the dependence structure of the jump components and
has important applications in finance. Our estimators are based on a threshold
principle allowing to isolate the jumps. This work follows Gobbi and Mancini
(2006) where the asymptotic normality for the estimator of the covariation,
with convergence speed given by the squared root of h, was obtained when the
jump components have finite activity. Here we show that the speed is the
squared root of h only when the activity of the jump components is moderate.


title:
Dipolar Poisson-Boltzmann Equation: Ions and Dipoles Close to Charged
  Surfaces

abstract:
  We present an extension to the Poisson-Boltzmann model where the dipolar
features of solvent molecules are taken explicitly into account. The
formulation is derived at mean-field level and can be extended to any order in
a systematic expansion. It is applied to a two-plate system with oppositely
charged surfaces. The ion distribution and profiles in the dipolar order
parameter are calculated and can result in a large correction to the
inter-plate pressure.


title:
Causal inference in longitudinal studies with history-restricted
  marginal structural models

abstract:
  A new class of Marginal Structural Models (MSMs), History-Restricted MSMs
(HRMSMs), was recently introduced for longitudinal data for the purpose of
defining causal parameters which may often be better suited for public health
research or at least more practicable than MSMs \citejoffe,feldman. HRMSMs
allow investigators to analyze the causal effect of a treatment on an outcome
based on a fixed, shorter and user-specified history of exposure compared to
MSMs. By default, the latter represent the treatment causal effect of interest
based on a treatment history defined by the treatments assigned between the
study's start and outcome collection. We lay out in this article the formal
statistical framework behind HRMSMs. Beyond allowing a more flexible causal
analysis, HRMSMs improve computational tractability and mitigate statistical
power concerns when designing longitudinal studies. We also develop three
consistent estimators of HRMSM parameters under sufficient model assumptions:
the Inverse Probability of Treatment Weighted (IPTW), G-computation and Double
Robust (DR) estimators. In addition, we show that the assumptions commonly
adopted for identification and consistent estimation of MSM parameters
(existence of counterfactuals, consistency, time-ordering and sequential
randomization assumptions) also lead to identification and consistent
estimation of HRMSM parameters.


title:
Design of a 3 Axis Parallel Machine Tool for High Speed Machining: The
  Orthoglide

abstract:
  The Orthoglide project aims at designing a new 3-axis machine tool for High
Speed Machining. Basis kinematics is a 3 degree-of-freedom translational
parallel mechanism. This basis was submitted to isotropic and manipulability
constraints that allowed the optmization of its kinematic architecture and legs
architecture. Thus, several leg morphologies are convenient for the chosen
mechanism. We explain the process that led us to the choice we made for the
Orthoglide. A static study is presented to show how singular configurations of
the legs can cause stiffness problems.


title: The Isoconditioning Loci of Planar Three-DOF Parallel Manipulators

abstract:
  The subject of this paper is a special class of parallel manipulators. First,
we analyze a family of three-degree-of-freedom manipulators. Two Jacobian
matrices appear in the kinematic relations between the joint-rate and the
Cartesian-velocity vectors, which are called the "inverse kinematics" and the
"direct kinematics" matrices. The singular configurations of these matrices are
studied. The isotropic configurations are then studied based on the
characteristic length of this manipulator. The isoconditioning loci of all
Jacobian matrices are computed to define a global performance index to compare
the different working modes.


title: On regularity of SLE_8 curves

abstract:
  This paper has been withdrawn by the author due to essential mistakes in some
previous versions.


title: Generation and amplification of Raman Stokes and anti-Stokes waves

abstract:
  We present general analytical expressions of Stokes and anti-Stokes spectral
photon-flux densities that are spontaneously generated by a single
monochromatic pump wave propagating in a single-mode optical fiber. We validate
our results by comparing them with experimental data. Limiting cases of the
general expressions corresponding to interesting physical situations are
discussed.


title:
Weakly-Interacting Bosons in a Trap within Approximate Second
  Quantization Approach

abstract:
  The theory of Bogoliubov is generalized for the case of a weakly-interacting
Bose-gas in harmonic trap. A set of nonlinear matrix equations is obtained to
make the diagonalization of Hamiltonian possible. Its perturbative solution is
used for the calculation of the energy and the condensate fraction of the model
system to show the applicability of the method.


title: Subadditivity of q-entropies for q>1

abstract:
  I prove a basic inequality for Schatten q-norms of quantum states on a
finite-dimensional bipartite Hilbert space H_1\otimes H_2: 1+||\rho||_q \ge
||\trace_1\rho||_q + ||\trace_2\rho||_q. This leads to a proof--in the finite
dimensional case--of Raggio's conjecture (G.A. Raggio, J. Math. Phys.\
\textbf{36}, 4785--4791 (1995)) that the q-entropies
S_q(\rho)=(1-\trace[\rho^q])/(q-1) are subadditive for q > 1; that is, for any
state \rho, S_q(\rho) is not greater than the sum of the S_q of its reductions,
S_q(\rho) \le S_q(\trace_1\rho)+S_q(\trace_2\rho).


title:
Strongly Interacting Low Viscosity Matter Created in Heavy Ion
  Collisions

abstract:
  Substantial collective flow is observed in collisions between large nuclei at
high energy, as evidenced by single-particle transverse momentum distributions
and by azimuthal correlations among the produced particles. The data are
well-reproduced by perfect fluid dynamics. In a separate development,
calculation of the dimensionless ratio of shear viscosity eta to entropy
density s by Kovtun, Son and Starinets within AdS/CFT yields eta/s = 1/4pi, and
they conjectured that this is a lower bound for any physical system. It is
shown that the transition from hadrons to quarks and gluons has behavior
similar to helium, nitrogen, and water at and near their phase transitions in
the ratio eta/s. Therefore it is possible that experimental measurements can
pinpoint the location of this transition or rapid crossover in QCD via the
viscosity to entropy ratio in addition to and independently of the equation of
state.


title:
Multiwavelength Study of X-ray Selected Star Forming Galaxies within the
  Chandra Deep Field South

abstract:
  We have combined multi-wavelength observations of a selected sample of
starforming galaxies with galaxy evolution models in order to compare the
results obtained for different SFR tracers and to study the effect that the
evolution of the starforming regions has on them. We also aimed at obtaining a
better understanding of the corrections due to extinction and nuclear activity
on the derivation of the SFR. We selected the sample from Chandra data for the
well studied region Chandra Deep Field South (CDFS) and chose the objects that
also have UV and IR data from GALEX and GOODS-Spitzer respectively.
  Our main finding is that there is good agreement between the extinction
corrected SFR(UV) and the SFR(X), and we confirm the use of X-ray luminosities
as a trustful tracer of recent star formation activity. Nevertheless, at
SFR(UV) larger than about 5Msol/year there are several galaxies with an excess
of SFR(X) suggesting the presence of an obscured AGN not detected in the
optical spectra. We conclude that the IR luminosity is driven by recent star
formation even in those galaxies where the SFR(X) is an order of magnitude
higher than the SFR(UV) and therefore may harbour an AGN. One object shows
SFR(X) much lower than expected based on the SFR(UV); this SFR(X) `deficit' may
be due to an early transient phase before most of the massive X-ray binaries
were formed. An X-ray deficit could be used to select extremely young bursts in
an early phase just after the explosion of the first supernovae associated with
massive stars and before the onset of massive X-ray binaries.


title:
A novel characterization of the Iwasawa decomposition of a simple Lie
  group

abstract: It is about the uniqueness of the Iwasawa decomposition.


title:
A Novel method for the design of 2-DOF Parallel mechanisms for machining
  applications

abstract:
  Parallel Kinematic Mechanisms (PKM) are interesting alternative designs for
machine tools. A design method based on velocity amplification factors analysis
is presented in this paper. The comparative study of two simple
two-degree-of-freedom PKM dedicated to machining applications is led through
this method: the common desired properties are the largest square Cartesian
workspace for given kinetostatic performances. The orientation and position of
the Cartesian workspace are chosen to avoid singularities and to produce the
best ratio between Cartesian workspace size and mechanism size. The machine
size of each resulting design is used as a comparative criterion.


title: Viscous potential free-surface flows in a fluid layer of finite depth

abstract:
  It is shown how to model weakly dissipative free-surface flows using the
classical potential flow approach. The Helmholtz-Leray decomposition is applied
to the linearized 3D Navier-Stokes equations. The governing equations are
treated using Fourier--Laplace transforms. We show how to express the vortical
component of the velocity only in terms of the potential and free-surface
elevation. A new predominant nonlocal viscous term is derived in the bottom
kinematic boundary condition. The resulting formulation is simple and does not
involve any correction procedure as in previous viscous potential flow theories
[Joseph2004]. Corresponding long wave model equations are derived.

categories: physics.ao-ph math-ph math.MP nlin.SI physics.class-ph physics.flu-dyn physics.gen-ph


title:
Design of a Three-Axis Isotropic Parallel Manipulator for Machining
  Applications: The Orthoglide

abstract:
  The orthoglide is a 3-DOF parallel mechanism designed at IRCCyN for machining
applications. It features three fixed parallel linear joints which are mounted
orthogonally and a mobile platform which moves in the Cartesian x-y-z space
with fixed orientation. The orthoglide has been designed as function of a
prescribed Cartesian workspace with prescribed kinetostatic performances. The
interesting features of the orthoglide are a regular Cartesian workspace shape,
uniform performances in all directions and good compactness. A small-scale
prototype of the orthoglide under development is presented at the end of this
paper.


title:
Cs CPT magnetometer for cardio-signal detection in unshielded
  environment

abstract:
  We present first, encouraging results obtained with an experimental apparatus
based on Coherent Population Trapping and aimed at detecting biological
(cardiac) magnetic field in magnetically compensated, but unshielded volume.
The work includes magnetic-field and magnetic-field-gradient compensation and
uses differential detection for cancellation of (common mode) magnetic noise.
Synchronous data acquisition with a reference (electro-cardiographic or
pulse-oximetric) signal allows for improving the S/N in an off-line averaging.
The set-up has the relevant advantages of working at room temperature with a
small-size head, and of allowing for fast adjustments of the dc bias magnetic
field, which results in making the sensor suitable for detecting the
bio-magnetic signal at any orientation with respect to the heart axis and in
any position around the patient chest, which is not the case with other kinds
of magnetometers.


title: Workspace Analysis of the Orthoglide using Interval Analysis

abstract:
  This paper addresses the workspace analysis of the orthoglide, a 3-DOF
parallel mechanism designed for machining applications. This machine features
three fixed parallel linear joints which are mounted orthogonally and a mobile
platform which moves in the Cartesian x-y-z space with fixed orientation. The
workspace analysis is conducted on the bases of prescribed kinetostatic
performances. The interesting features of the orthoglide are a regular
Cartesian workspace shape, uniform performances in all directions and good
compactness. Interval analysis based methods for computing the dextrous
workspace and the largest cube enclosed in this workspace are presented.


title:
P\'eriph\'eriques haptiques et simulation d'objets, de robots et de
  mannequins dans un environnement de CAO-Robotique : eM-Virtual Desktop

abstract:
  This paper presents the development of a new software in order to manage
objects, robots and mannequins in using the possibilities given by the haptic
feedback of the Phantom desktop devices. The haptic device provides 6
positional degree of freedom sensing but three degrees force feedback. This
software called eM-Virtual Desktop is integrated in the Tecnomatix's solution
called eM-Workplace. The eM-Workplace provides powerful solutions for planning
and designing of complex assembly facilities, lines and workplaces. In the
digital mockup context, the haptic interfaces can be used to reduce the
development cycle of products. Three different loops are used to manage the
graphic, the collision detection and the haptic feedback according to theirs
own frequencies. The developed software is currently tested in industrial
context by a European automotive constructor.


title: On Power Stable Ideals

abstract:
  We define the notion of a power stable ideal in a polynomial ring $ R[X]$
over an integral domain $ R $. It is proved that a maximal ideal $\chi$ $ M $
in $ R[X]$ is power stable if and only if $ P^t $ is $ P$- primary for all $
t\geq 1 $ for the prime ideal $ P = M \cap R $. Using this we prove that for a
Hilbert domain $R$ any radical ideal in $R[X]$ which is a finite intersection
G-ideals is power stable. Further, we prove that if $ R $ is a Noetherian
integral domain of dimension 1 then any radical ideal in $ R[X] $ is power
stable. Finally, it is proved that if every ideal in $ R[X]$ is power stable
then $ R $ is a field.


title: Uniform random sampling of planar graphs in linear time

abstract:
  This article introduces new algorithms for the uniform random generation of
labelled planar graphs. Its principles rely on Boltzmann samplers, as recently
developed by Duchon, Flajolet, Louchard, and Schaeffer. It combines the
Boltzmann framework, a suitable use of rejection, a new combinatorial bijection
found by Fusy, Poulalhon and Schaeffer, as well as a precise analytic
description of the generating functions counting planar graphs, which was
recently obtained by Gim\'enez and Noy. This gives rise to an extremely
efficient algorithm for the random generation of planar graphs. There is a
preprocessing step of some fixed small cost. Then, the expected time complexity
of generation is quadratic for exact-size uniform sampling and linear for
approximate-size sampling. This greatly improves on the best previously known
time complexity for exact-size uniform sampling of planar graphs with $n$
vertices, which was a little over $O(n^7)$.


title: Predicting the Presence of Internet Worms using Novelty Detection

abstract:
  Internet worms cause billions of dollars in damage yearly, affecting millions
of users worldwide. For countermeasures to be deployed timeously, it is
necessary to use an automated system to detect the spread of a worm. This paper
discusses a method of determining the presence of a worm, based on routing
information currently available from Internet routers. An autoencoder, which is
a specialized type of neural network, was used to detect anomalies in normal
routing behavior. The autoencoder was trained using information from a single
router, and was able to detect both global instability caused by worms as well
as localized routing instability.


title: Discrete Thermodynamics of Lasers

abstract:
  The paper offers a discrete thermodynamic model of lasers. Laser is an open
system; its equilibrium is based on a balance of two thermodynamic forces, one
related to the incoming pumping power and another to the emitted light. The
basic expression for such equilibrium is a logistic map, graphical solutions to
which are pitchfork bifurcation diagrams. As pumping force increases, the
relative populations on the ground and lasing branches tend to zero and unity
correspondingly. An interesting feature of this model is the line spectrum of
the up and down transitions between the branches beyond bifurcation point. Even
in a simple case of 2-level laser with only 2 possible transition types (up and
down), the spectra look like sets of the line packets, starting well before the
population inversion. This effect is an independent confirmation of the
Einstein's prohibition on practical realization of 2-level laser. Multilevel
lasers may be approached by employing the idea of thermodynamic activity for
the emitting atoms. Considering coefficient of thermodynamic activity of the
lasing level atoms to be proportional to the ratio of life times on the upper
and lasing (the 3d) levels, one can derive a new basic map for the multilevel
laser system. For a modest ratio only of 0.01, spontaneous transitions between
levels are pushed to the area beyond population inversion, opening a space for
the functioning of laser.


title: Landscape Implications of Extended Higgs Models

abstract:
  From several points of view it is strongly suggested that the current
universe is unstable and will ultimately decay to one that is exactly
supersymmetric (susy). The possibility that atoms and molecules form in this
future universe requires that the degenerate electron/selectron mass is
non-zero and hence that electroweak symmetry breaking (EWSB) survives the phase
transition to exact susy. However, the minimal supersymmetric standard model
(MSSM) and several of its extensions have no EWSB in the susy limit. Among the
extended higgs models that have been discussed one stands out in this regard.
The higgs sector that is revealed at the Large Hadron Collider (LHC) will
therefore have implications for the future universe. We also address the
question as to whether the transition to the exact susy phase with EWSB is
exothermic.


title: Spinodal decomposition of low-density asymmetric nuclear matter

abstract:
  We investigate the dynamical properties of asymmetric nuclear matter at low
density. The occurrence of new instabilities, that lead the system to a
dynamical fragment formation, is illustrated, discussing in particular the
charge symmetry dependence of the structure of the most important unstable
modes. We observe that instabilities are reduced by charge asymmetry, leading
to larger size and time scales in the fragmentation process. Configurations
with less asymmetric fragments surrounded by a more asymmetric gas are
favoured. Interesting variances with respect to a pure thermodynamical
prediction are revealed, that can be checked experimentally. All these features
are deeply related to the structure of the symmetry term in the nuclear
Equation of State (EOS) and could be used to extract information on the low
density part of the EOS.


title: Improved estimation of Fokker-Planck equations through optimisation

abstract:
  An improved method for the description of hierarchical complex systems by
means of a Fokker-Planck equation is presented. In particular the
limited-memory Broyden-Fletcher-Goldfarb-Shanno algorithm for constraint
problems (L-BFGS-B) is used to minimize the distance between the numerical
solutions of the Fokker-Planck equation and the empirical probability density
functions and thus to estimate properly the drift and diffusion term of the
Fokker-Planck equation. The optimisation routine is applied to a time series of
velocity measurements obtained from a turbulent helium gas jet in order to
demonstrate the benefits and to quantify the improvements of this new
optimisation routine.


title: Some result on K-algebras

abstract:
  We give a new proof of the classical result due to Rodney Y. Sharp and Peter
Vamos on the dimension of tensor product of a finite number of field extensions
of a given field.


title:
On a class of rational matrices and interpolating polynomials related to
  the discrete Laplace operator

abstract:
  Let $\dlap$ be the discrete Laplace operator acting on functions (or rational
matrices) $f:\mathbf{Q}_L\to\mathbb{Q}$, where $\mathbf{Q}_L$ is the two
dimensional lattice of size $L$ embedded in $\mathbb{Z}_2$. Consider a rational
$L\times L$ matrix $\mathcal{H}$, whose inner entries $\mathcal{H}_{ij}$
satisfy $\dlap\mathcal{H}_{ij}=0$. The matrix $\mathcal{H}$ is thus the
classical finite difference five-points approximation of the Laplace operator
in two variables. We give a constructive proof that $\mathcal{H}$ is the
restriction to $\mathbf{Q}_L$ of a discrete harmonic polynomial in two
variables for any $L>2$. This result proves a conjecture formulated in the
context of deterministic fixed-energy sandpile models in statistical mechanics.


title:
Violation of the `Zero-Force Theorem' in the time-dependent
  Krieger-Li-Iafrate approximation

abstract:
  We demonstrate that the time-dependent Krieger-Li-Iafrate approximation in
combination with the exchange-only functional violates the `Zero-Force
Theorem'. By analyzing the time-dependent dipole moment of Na5 and Na9+, we
furthermore show that this can lead to an unphysical self-excitation of the
system depending on the system properties and the excitation strength.
Analytical aspects, especially the connection between the `Zero-Force Theorem'
and the `Generalized-Translation Invariance' of the potential, are discussed.


title: Several new actions of $p$-branes based on bulk scalar fields

abstract:
  Generally, $p$-branes play central roles in revealing the nonperturbative
structures of the string/M-theory. In this paper, through a topological tensor
current constructed in terms of a bulk scalar field, we first show some
topological properties of $p$-branes, and then mainly discuss the construction
of several new actions of $p$-branes. We show that the actions we construct
which can be reduced to the Nambu-Goto action or some other simple actions, are
all defined naturally in the bulk spacetime, preserving the full spacetime
Lorentz invariance and satisfying a self-dual condition.


title:
Pricing Life Insurance under Stochastic Mortality via the Instantaneous
  Sharpe Ratio: Theorems and Proofs

abstract:
  We develop a pricing rule for life insurance under stochastic mortality in an
incomplete market by assuming that the insurance company requires compensation
for its risk in the form of a pre-specified instantaneous Sharpe ratio. Our
valuation formula satisfies a number of desirable properties, many of which it
shares with the standard deviation premium principle. The major result of the
paper is that the price per contract solves a linear partial differential
equation as the number of contracts approaches infinity. One can interpret the
limiting price as an expectation with respect to an equivalent martingale
measure. Another important result is that if the hazard rate is stochastic,
then the risk-adjusted premium is greater than the net premium, even as the
number of contracts approaches infinity. We present a numerical example to
illustrate our results, along with the corresponding algorithms.


title: Mykyta the Fox and networks of language

abstract:
  The results of quantitative analysis of word distribution in two fables in
Ukrainian by Ivan Franko: "Mykyta the Fox" and "Abu-Kasym's slippers" are
reported. Our study consists of two parts: the analysis of frequency-rank
distributions and the application of complex networks theory. The analysis of
frequency-rank distributions shows that the text sizes are enough to observe
statistical properties. The power-law character of these distributions (Zipf's
law) holds in the region of rank variable r=20 - 3000 with an exponent
$\alpha\simeq 1$. This substantiates the choice of the above texts to analyse
typical properties of the language complex network on their basis. Besides, an
applicability of the Simon model to describe non-asymptotic properties of word
distributions is evaluated.
  In describing language as a complex network, usually the words are associated
with nodes, whereas one may give different meanings to the network links. This
results in different network representations. In the second part of the paper,
we give different representations of the language network and perform
comparative analysis of their characteristics. Our results demonstrate that the
language network of Ukrainian is a strongly correlated scale-free small world.
Empirical data obtained may be useful for theoretical description of language
evolution.


title: Ultracold Rydberg Atoms in a Ioffe-Pritchard Trap

abstract:
  We discuss the properties of ultracold Rydberg atoms in a Ioffe-Pritchard
magnetic field configuration. The derived two-body Hamiltonian unveils how the
large size of Rydberg atoms affects their coupling to the inhomogeneous
magnetic field. The properties of the compound electronic and center of mass
quantum states are thoroughly analyzed. We find very tight confinement of the
center of mass motion in two dimensions to be achievable while barely changing
the electronic structure compared to the field free case. This paves the way
for generating a one-dimensional ultracold quantum Rydberg gas.


title: Domino Tiling Congruence Modulo 4

abstract:
  The number of domino tilings of a region with reflective symmetry across a
line is combinatorially shown to depend on the number of domino tilings of
particular subregions, modulo 4. This expands upon previous congruency results
for domino tilings, modulo 2, and leads to a variety of corollaries, including
that the number of domino tilings of a k x 2k rectangle is congruent to 1 mod
4.


title: Massive gravity and structure formation

abstract:
  We study the growth of cosmological perturbations in the model of
Lorentz-violating massive gravity. The Friedman equation in this model acquires
an unconventional term due to the Lorentz-breaking condensates which has the
equation of state w = -1 / (3 gamma) with gamma being a free parameter taking
values outside of the range [0,1/3]. Apart from the standard contributions, the
perturbations above the Friedmann background contain an extra piece which is
proportional to an arbitrary function theta(x) of the space coordinates. This
function appears as an integration constant and corresponds to a
non-propagating scalar mode which may, however, become dynamical with the
account of the higher-derivative corrections. For -1 < gamma < 0 and gamma = 1
the ``anomalous'' perturbations grow slower than the standard ones and thus the
model is compatible with observations. Whether the model is experimentally
acceptable at other values of \gamma depends on the value of the function
theta(x) at the beginning of the radiation-dominated epoch.


title:
Financial Valuation of Mortality Risk via the Instantaneous Sharpe
  Ratio: Applications to Pricing Pure Endowments

abstract:
  We develop a theory for pricing non-diversifiable mortality risk in an
incomplete market. We do this by assuming that the company issuing a
mortality-contingent claim requires compensation for this risk in the form of a
pre-specified instantaneous Sharpe ratio. We prove that our ensuing valuation
formula satisfies a number of desirable properties. For example, we show that
it is subadditive in the number of contracts sold. A key result is that if the
hazard rate is stochastic, then the risk-adjusted survival probability is
greater than the physical survival probability, even as the number of contracts
approaches infinity.


title:
Interplay of size and Landau quantizations in the de Haas-van Alphen
  oscillations of metallic nanowires

abstract:
  We examine the interplay between size quantization and Landau quantization in
the De Haas-Van Alphen oscillations of clean, metallic nanowires in a
longitudinal magnetic field for `hard' boundary conditions, i.e. those of an
infinite round well, as opposed to the `soft' parabolically confined boundary
conditions previously treated in Alexandrov and Kabanov (Phys. Rev. Lett. {\bf
95}, 076601 (2005) (AK)). We find that there exist {\em two} fundamental
frequencies as opposed to the one found in bulk systems and the three
frequencies found by AK with soft boundary counditions. In addition, we find
that the additional `magic resonances' of AK may be also observed in the
infinite well case, though they are now damped. We also compare the numerically
generated energy spectrum of the infinite well potential with that of our
analytic approximation, and compare calculations of the oscillatory portions of
the thermodynamic quantities for both models.


title: E(11) and the Embedding Tensor

abstract:
  We show how, using different decompositions of E(11), one can calculate the
representations under the duality group of the so--called "de-form" potentials.
Evidence is presented that these potentials are in one-to-one correspondence to
the embedding tensors that classify the gaugings of all maximal gauged
supergravities. We supply the computer program underlying our calculations.


title: Analysis of a power grid using the Kuramoto-like model

abstract:
  We show that there is a link between the Kuramoto paradigm and another system
of synchronized oscillators, namely an electrical power distribution grid of
generators and consumers. The purpose of this work is to show both the formal
analogy and some practical consequences. The mapping can be made quantitative,
and under some necessary approximations a class of Kuramoto-like models, those
with bimodal distribution of the frequencies, is most appropriate for the
power-grid. In fact in the power-grid there are two kinds of oscillators: the
'sources' delivering power to the 'consumers'.


title: Observational Constraints on Interstellar Grain Alignment

abstract:
  We present new multicolor photo-polarimetry of stars behind the Southern
Coalsack. Analyzed together with multiband polarization data from the
literature, probing the Chamaeleon I, Musca, rho Opiuchus, R CrA and Taurus
clouds, we show that the wavelength of maximum polarization (lambda_max) is
linearly correlated with the radiation environment of the grains. Using
Far-Infrared emission data, we show that the large scatter seen in previous
studies of lambda_max as a function of A_V is primarily due to line of sight
effects causing some A_V measurements to not be a good tracer of the extinction
(radiation field strength) seen by the grains being probed. The derived slopes
in lambda_max vs. A_V, for the individual clouds, are consistent with a common
value, while the zero intercepts scale with the average values of the ratios of
total-to-selective extinction (R_V) for the individual clouds. Within each
cloud we do not find direct correlations between lambda_max and R_V. The
positive slope in consistent with recent developments in theory and indicating
alignment driven by the radiation field. The present data cannot conclusively
differentiate between direct radiative torques and alignment driven by H_2
formation. However, the small values of lambda_max(A_V=0), seen in several
clouds, suggest a role for the latter, at least at the cloud surfaces. The
scatter in the lambda_max vs. A_V relation is found to be associated with the
characteristics of the embedded Young Stellar Objects (YSO) in the clouds. We
propose that this is partially due to locally increased plasma damping of the
grain rotation caused by X-rays from the YSOs.


title:
Controlling posture using a plantar pressure-based, tongue-placed
  tactile biofeedback system

abstract:
  The present paper introduces an original biofeedback system for improving
human balance control, whose underlying principle consists in providing
additional sensory information related to foot sole pressure distribution to
the user through a tongue-placed tactile output device. To assess the effect of
this biofeedback system on postural control during quiet standing, ten young
healthy adults were asked to stand as immobile as possible with their eyes
closed in two conditions of No-biofeedback and Biofeedback. Centre of foot
pressure (CoP) displacements were recorded using a force platform. Results
showed reduced CoP displacements in the Biofeedback relative to the
No-biofeedback condition. The present findings evidenced the ability of the
central nervous system to efficiently integrate an artificial plantar-based,
tongue-placed tactile biofeedback for controlling control posture during quiet
standing.


title: Quantify Entanglement for Multipartite Quantum States

abstract:
  In this paper, we consider the problem of how to quantify entanglement for
any multipartite quantum states. For bipartite pure states partial entropy is a
good entanglement measure. By using partial entropy, we firstly introduce the
Combinatorial Entropy of Fully entangled states (CEF) which can be used to
quantify entanglement for any fully entangled pure states. In order to quantify
entanglement for any multipartite states we also need another concept the
Entanglement Combination (EC) which can be used to completely describe the
entanglement between any parties of the given quantum states. Combining CEF
with EC, we define the Combinatorial Entropy (CE) for any multipartite pure
states and present some nice properties which indicate CE is a good
entanglement measure. Finally, we point out the feasibility of extending these
three concepts to mixed quantum states.


title: Robust Multi-Cellular Developmental Design

abstract:
  This paper introduces a continuous model for Multi-cellular Developmental
Design. The cells are fixed on a 2D grid and exchange "chemicals" with their
neighbors during the growth process. The quantity of chemicals that a cell
produces, as well as the differentiation value of the cell in the phenotype,
are controlled by a Neural Network (the genotype) that takes as inputs the
chemicals produced by the neighboring cells at the previous time step. In the
proposed model, the number of iterations of the growth process is not
pre-determined, but emerges during evolution: only organisms for which the
growth process stabilizes give a phenotype (the stable state), others are
declared nonviable. The optimization of the controller is done using the NEAT
algorithm, that optimizes both the topology and the weights of the Neural
Networks. Though each cell only receives local information from its neighbors,
the experimental results of the proposed approach on the 'flags' problems (the
phenotype must match a given 2D pattern) are almost as good as those of a
direct regression approach using the same model with global information.
Moreover, the resulting multi-cellular organisms exhibit almost perfect
self-healing characteristics.


title: A General Fredholm Theory II: Implicit Function Theorems

abstract:
  This is the revised version of the second paper in a series introducing a
generalized Fredholm theory in a new class of smooth spaces called polyfolds.
The theory will be illustrated in upcoming papers by applications to Floer
Theory, Gromov-Witten Theory and Symplectic Field Theory.
  Some proofs have been improved and a glossary added.


title:
Galaxy clustering constraints on deviations from Newtonian gravity at
  cosmological scales II: Perturbative and numerical analyses of power spectrum
  and bispectrum

abstract:
  We explore observational constraints on possible deviations from Newtonian
gravity by means of large-scale clustering of galaxies. We measure the power
spectrum and the bispectrum of Sloan Digital Sky Survey galaxies and compare
the result with predictions in an empirical model of modified gravity. Our
model assumes an additional Yukawa-like term with two parameters that
characterize the amplitude and the length scale of the modified gravity. The
model predictions are calculated using two methods; the second-order
perturbation theory and direct N-body simulations. These methods allow us to
study non-linear evolution of large-scale structure. Using the simulation
results, we find that perturbation theory provides reliable estimates for the
power spectrum and the bispectrum in the modified Newtonian model. We also
construct mock galaxy catalogues from the simulations, and derive constraints
on the amplitude and the length scale of deviations from Newtonian gravity. The
resulting constraints from power spectrum are consistent with those obtained in
our earlier work, indicating the validity of the previous empirical modeling of
gravitational nonlinearity in the modified Newtonian model. If linear biasing
is adopted, the bispectrum of the SDSS galaxies yields constraints very similar
to those from the power spectrum. If we allow for the nonlinear biasing
instead, we find that the ratio of the quadratic to linear biasing
coefficients, b_2/b_1, should satisfy -0.4 < b_2/b_1<0.3 in the modified
Newtonian model.


title: Tidal Dynamics in Cosmological Spacetimes

abstract:
  We study the relative motion of nearby free test particles in cosmological
spacetimes, such as the FLRW and LTB models. In particular, the influence of
spatial inhomogeneities on local tidal accelerations is investigated. The
implications of our results for the dynamics of the solar system are briefly
discussed. That is, on the basis of the models studied in this paper, we
estimate the tidal influence of the cosmic gravitational field on the orbit of
the Earth around the Sun and show that the corresponding temporal rate of
variation of the astronomical unit is negligibly small.


title:
Study of $^{64}$Ni+$^{132}$Sn Fusion with Density Constrained TDHF
  Formalism

abstract:
  We study fusion reactions of the $^{64}$Ni+$^{132}$Sn system using the
recently introduced density constrained time-dependent Hartree-Fock formalism.
In this formalism the fusion barriers are directly obtained from TDHF dynamics.
In addition, we incorporate the entrance channel alignment of the deformed
(oblate) $^{64}$Ni nucleus due to dynamical Coulomb excitation. We discuss the
influence of particle transfer and other dynamical effects on the fusion cross
sections. Calculated cross sections are in very good agreement with data and
other calculations.


title: VO: A Strongly Correlated Metal Close to a Mott- Hubbard Transition

abstract:
  Here we present experimental and computational evidences to support that
rock-salt cubic VO is a strongly correlated metal with Non-Fermi-Liquid
thermodynamics and an unusually strong spin-lattice coupling. An unexpected
change of sign of metallic thermopower with composition is tentatively ascribed
to the presence of a pseudogap in the density of states. These properties are
discussed as signatures of the proximity to a magnetic quantum phase
transition. The results are summarized in a new electronic phase diagram for
the 3d monoxides, which resembles that of other strongly correlated systems.
The structural and electronic simplicity of 3d monoxides make them ideal
candidates to progress in the understanding of highly correlated electron
systems.


title: Multi-year search for a diffuse flux of muon neutrinos with AMANDA-II

abstract:
  A search for TeV - PeV muon neutrinos from unresolved sources was performed
on AMANDA-II data collected between 2000 and 2003 with an equivalent livetime
of 807 days. This diffuse analysis sought to find an extraterrestrial neutrino
flux from sources with non-thermal components. The signal is expected to have a
harder spectrum than the atmospheric muon and neutrino backgrounds. Since no
excess of events was seen in the data over the expected background, an upper
limit of E^{2}\Phi_{90% C.L.} < 7.4 x 10^{-8} GeV cm^{-2} s^{-1} sr^{-1} is
placed on the diffuse flux of muon neutrinos with a \Phi \propto E^{-2}
spectrum in the energy range 16 TeV to 2.5 PeV. This is currently the most
sensitive \Phi \propto E^{-2} diffuse astrophysical neutrino limit. We also set
upper limits for astrophysical and prompt neutrino models, all of which have
spectra different than \Phi \propto E^{-2}.


title: Novikov algebras and Novikov structures on Lie algebras

abstract:
  We study ideals of Novikov algebras and Novikov structures on
finite-dimensional Lie algebras. We present the first example of a three-step
nilpotent Lie algebra which does not admit a Novikov structure. On the other
hand we show that any free three-step nilpotent Lie algebra admits a Novikov
structure. We study the existence question also for Lie algebras of triangular
matrices. Finally we show that there are families of Lie algebras of arbitrary
high solvability class which admit Novikov structures.


title: Cosmic microwave background dipole, peculiar velocity and Hubble flow

abstract:
  Two types of cosmology are discussed and their implications for the observed
cmb (cosmic microwave background radiation) dipole are described. Theorems
useful for understanding the cause for a cmb dipole are presented. Since the
present peculiar velocity of the solar system relative to the GA (Great
Attracter) cannot explain the observed cmb dipole, the author presents the
possibility of Hubble flow of the GA as a cause in one case and a further
peculiar velocity of the GA in the other case.


title: Supersymmetry and Nuclear Pairing

abstract:
  We show that nuclear pairing Hamiltonian exhibits supersymmetry in the
strong-coupling limit. The underlying supersymmetric quantum mechanical
structure explains the degeneracies between the energies of the N and Nmax-N+1
pair eigenstates. The supersymmetry transformations connecting these states are
given.


title: Low-lying magnetic loops in the solar internetwork

abstract:
  The aim of this work is to study the structure of the magnetic field vector
in the internetwork and search for the presence of small-scale loops. We invert
1.56 micron spectropolarimetric observations of internetwork regions at disc
centre by applying the SIR code. This allows us to recover the atmospheric
parameters that play a role in the formation of these spectral lines. We are
mainly interested in the structure of the magnetic field vector. We find that
many opposite polarity elements of the internetwork are connected by short
(2-6''), low-lying (photospheric) loops. These loops connect at least the 10-20
% of the internetwork flux visible in our data. Also we have some evidence that
points towards a dynamic scenario which can be produced by the emergence of
internetwork magnetic flux.


title: Finite-size scaling of directed percolation in the steady state

abstract:
  Recently, considerable progress has been made in understanding finite-size
scaling in equilibrium systems. Here, we study finite-size scaling in
non-equilibrium systems at the instance of directed percolation (DP), which has
become the paradigm of non-equilibrium phase transitions into absorbing states,
above, at and below the upper critical dimension. We investigate the
finite-size scaling behavior of DP analytically and numerically by considering
its steady state generated by a homogeneous constant external source on a
d-dimensional hypercube of finite edge length L with periodic boundary
conditions near the bulk critical point. In particular, we study the order
parameter and its higher moments using renormalized field theory. We derive
finite-size scaling forms of the moments in a one-loop calculation. Moreover,
we introduce and calculate a ratio of the order parameter moments that plays a
similar role in the analysis of finite size scaling in absorbing nonequilibrium
processes as the famous Binder cumulant in equilibrium systems and that, in
particular, provides a new signature of the DP universality class. To
complement our analytical work, we perform Monte Carlo simulations which
confirm our analytical results.


title: Mutant knots with symmetry

abstract:
  Mutant knots, in the sense of Conway, are known to share the same Homfly
polynomial. Their 2-string satellites also share the same Homfly polynomial,
but in general their m-string satellites can have different Homfly polynomials
for m>2. We show that, under conditions of extra symmetry on the constituent
2-tangles, the directed m-string satellites of mutants share the same Homfly
polynomial for m<6 in general, and for all choices of m when the satellite is
based on a cable knot pattern.
  We give examples of mutants with extra symmetry whose Homfly polynomials of
some 6-string satellites are different, by comparing their quantum sl(3)
invariants.


title:
Algebraic approach to multiple defects on the line and application to
  Casimir force

abstract:
  An algebraic framework for quantization in presence of arbitrary number of
point-like defects on the line is developed. We consider a scalar field which
interacts with the defects and freely propagates away of them. As an
application we compute the Casimir force both at zero and finite temperature.
We derive also the charge density in the Gibbs state of a complex scalar field
with defects. The example of two delta-defects is treated in detail.