title:
Multiple equilibria of nonhomogeneous Markov chains and self-validating
  web rankings

abstract:
  PageRank is a ranking of the web pages that measures how often a given web
page is visited by a random surfer on the web graph, for a simple model of web
surfing. It seems realistic that PageRank may also have an influence on the
behavior of web surfers. We propose here a simple model taking into account the
mutual influence between web ranking and web surfing. Our ranking, the
T-PageRank, is a nonlinear generalization of the PageRank. It is defined as the
limit, if it exists, of some nonlinear iterates. A positive parameter T, the
temperature, measures the confidence of the web surfer in the web ranking. We
prove that, when the temperature is large enough, the T-PageRank is unique and
the iterates converge globally on the domain. But when the temperature is
small, there may be several T-PageRanks, that may strongly depend on the
initial ranking. Our analysis uses results of nonlinear Perron-Frobenius
theory, Hilbert projective metric and Birkhoff's coefficient of ergodicity.


title: INTEGRAL and New Classes of High-Mass X-ray Binaries

abstract:
  The gamma-ray observatory INTEGRAL, launched in October 2002, produces a
wealth of discoveries and new results on compact high energy Galactic objects,
nuclear gamma-ray line emission, diffuse line and continuum emission, cosmic
background radiation, AGN and high energy transients. Two important
serendipitous discoveries made by the INTEGRAL mission are new classes of X-ray
binaries, namely the highly-obscured high-mass X-ray binaries, and the
super-giant fast transients. In this paper I will review the current status of
these discoveries.


title: About combinatorics, and observables

abstract:
  We investigate the most general "phase space" of configurations, consisting
of all possible ways of assigning elementary attributes, "energies", to
elementary positions, "cells". We discuss how this space possesses structures
that can be approximated by a quantum physics scenario. In particular, we
discuss how the Heisenberg's "Uncertainty Principle" and a "universe" with a
three-dimensional space arise, and what kind of mechanics rules it.


title:
Recombination kinetics of a dense electron-hole plasma in strontium
  titanate

abstract:
  We investigated the nanosecond-scale time decay of the blue-green light
emitted by nominally pure SrTiO$_3$ following the absorption of an intense
picosecond laser pulse generating a high density of electron-hole pairs. Two
independent components are identified in the fluorescence signal that show a
different dynamics with varying excitation intensity, and which can be
respectively modeled as a bimolecular and unimolecolar process. An
interpretation of the observed recombination kinetics in terms of interacting
electron and hole polarons is proposed.


title: The effect of isospin violation on scalar meson production

abstract:
  We investigate the isospin-violating mixing of the light scalar mesons
a0(980) and f0(980) within the unitarized chiral approach. Isospin-violating
effects are considered to leading order in the quark mass difference and
electromagnetism. In this approach both resonances are generated through
meson-meson dynamics. Our results provide a description of the mixing
phenomenon within a framework consistent with chiral symmetry and unitarity,
where these resonances are not predominantly quark-antiquark states. We discuss
in detail the reactions J/Psi to phi S, where S denotes a suitable pair of
pseudo--scalar mesons in the scalar channel, namely pi0 eta, K+K-, and K0 \bar
K^0. In this work predictions for the cross section in the kaon channels are
given for the first time with isospin violating effects included.


title: Linearly foliated Calabi-Yau n-folds I. First-order deformations

abstract:
  We consider classes of noncompact n-folds with trivial canonical bundle, that
are linear foliations on nonsingular projective varieties, in general without a
projection to the base. We obtain them as first-order deformations of total
spaces of vector bundles on those varieties.


title:
Organic versus Hybrid Coacervate Complexes : Co-Assembly and Adsorption
  Properties

abstract:
  We report the co-assembly and adsorption properties of coacervate complexes
made from polyelectrolyte-neutral block copolymers and oppositely charged
nanocolloids. The nanocolloids put under scrutiny were ionic surfactant
micelles and highly charged 7 nm cerium oxide (CeO2) nanoparticles. Static and
dynamic light scattering was used to investigate the microstructure and
stability of the organic and hybrid complexes. The microstructure of the
CeO2-based complexes was resolved using cryogenic transmission electronic
microscopy (Cryo-TEM), and it revealed that the cores were clusters made from
densely packed nanoparticles. In the concentration range of interest, c = 10-4
- 1 wt. %, the surfactant-based complexes were shown to exhibit a critical
association concentration (cac) whereas the nanoparticle-polymer hybrids did
not. The adsorption properties of the same complexes were investigated above
the cac by stagnation point adsorption reflectometry. The adsorbed amount was
measured as a function of time for polymers and complexes using anionically
charged silica and hydrophobic poly(styrene) substrates. It was found that all
complexes adsorbed readily on both types of substrates up to a level of 1 - 2
mg m-2 at stationary state. Upon rinsing however, the adsorbed layer was
removed for the surfactant-based systems, but not for the cerium oxide
clusters. As for the solution properties, these finding were interpreted in
terms of a critical association concentrations which are very different for
organic and hybrid complexes.


title: Million-Degree Plasma Pervading the Extended Orion Nebula

abstract:
  Most stars form as members of large associations within dense, very cold
(10-100 K) molecular clouds. The nearby giant molecular cloud in Orion hosts
several thousand stars of ages less than a few million years, many of which are
located in or around the famous Orion Nebula, a prominent gas structure
illuminated and ionized by a small group of massive stars (the Trapezium). We
present X-ray observations obtained with the X-ray Multi-Mirror satellite
XMM-Newton revealing that a hot plasma with a temperature of 1.7-2.1 million K
pervades the southwest extension of the nebula. The plasma, originating in the
strong stellar winds from the Trapezium, flows into the adjacent interstellar
medium. This X-ray outflow phenomenon must be widespread throughout our Galaxy.


title: An Exact Exprsssion of Pi(x)

abstract: The author states an exact expression of the distribution of primes.


title:
The second law of thermodynamics in the quantum Brownian oscillator at
  an arbitrary temperature

abstract:
  In the classical limit no work is needed to couple a system to a bath with
sufficiently weak coupling strength (or with arbitrarily finite coupling
strength for a linear system) at the same temperature. In the quantum domain
this may be expected to change due to system-bath entanglement. Here we show
analytically that the work needed to couple a single linear oscillator with
finite strength to a bath cannot be less than the work obtainable from the
oscillator when it decouples from the bath. Therefore, the quantum second law
holds for an arbitrary temperature. This is a generalization of the previous
results for zero temperature [1,2]; in the high temperature limit we recover
the classical behavior.


title:
First quintuplet frequency solution of a Blazhko variable: light curve
  analysis of RV UMa

abstract:
  RV UMa is one of the RRab stars showing regular large amplitude light curve
modulation. Extended photoelectric observations of RV UMa obtained at the
Konkoly Observatory were published by Kanyo (1976). The analysis of the data
was published by Kovacs (1995). After detecting an error in the reduction
procedure of the published Konkoly data, corrected photometric data are
presented with additional, previously unpublished measurements.
  The reanalysis of the combination of the corrected Konkoly data supplemented
with Preston & Spinrad's (1967) observations has led to the discovery that the
adequate mathematical model of the light curve is, in fact, a quintuplet,
instead of a triplet frequency solution. This finding has crucial importance in
the interpretation of the Blazhko phenomenon, as triplet (doublet) is the
preferred structure in the resonance models, quintuplet in the magnetic models.
  Period changes of both the pulsation and the modulation light variations of
RV UMa have been detected based on its century long photometric observations.
An overall anticorrelation between the pulsation and the modulation period
changes can be defined with dP_{Bl} / dP_0 = -8.6 pm 10^4 gradient, i.e., the
modulation period is longer if the pulsation period is shorter. Between 1946
and 1975 the pulsation and modulation periods showed, however, parallel
changes, which points to that there is no strict relation between the changes
in the periods of the pulsation and the modulation.


title: Hard X-ray view of Nearby Star Forming Regions

abstract:
  Chandra and XMM-Newton have surveyed several nearby star forming regions and
have greatly advanced our knowledge of X-ray emission from Young Stellar
Objects (YSOs). After briefly reviewing it I discuss the advancements in this
research field that could be possible with Simbol-X unique imaging capability
in the hard X-ray bandpass.


title: Charmed-Meson Fragmentation Functions with Finite-Mass Corrections

abstract:
  We elaborate the inclusive production of single heavy-flavored hadrons in
e^+e^- annihilation at next-to-leading order in the general-mass
variable-flavor-number scheme. In this framework, we determine non-perturbative
fragmentation functions for D^0, D^+, and D^{*+} mesons by fitting experimental
data from the Belle, CLEO, ALEPH, and OPAL Collaborations, taking dominant
electroweak corrections due to photonic initial-state radiation into account.
We assess the significance of finite-mass effects through comparisons with a
similar analysis in the zero-mass variable-flavor-number scheme. Under Belle
and CLEO experimental conditions, charmed-hadron mass effects on the phase
space turn out to be appreciable, while charm-quark mass effects on the
partonic matrix elements are less important.


title:
Abundance variations and first ionization potential trends during large
  stellar flares

abstract:
  The Solar First Ionization Potential (FIP) effect, where low-FIP elements are
enriched in the corona relative to the photosphere, while high-FIP abundances
remain unchanged, has been known for a long while. High resolution X-ray
spectroscopy has revealed that active stellar coronae show an opposite effect,
which was labeled the Inverse-FIP (IFIP) effect. The correlation found between
coronal activity and the FIP/IFIP bias suggested perhaps that flaring activity
is involved in switching from FIP to IFIP. This work aims at a more systematic
understanding of the FIP trends during stellar flares and complements an
earlier study based on Chandra alone. The eight brightest X-ray flares observed
with XMM-Newton are analyzed and compared with their respective quiescence
states. Together with six previous flares observed with Chandra, this
establishes the best currently available sample of flares. We look for
abundance variations during the flare and their correlation with FIP. For that
purpose, we define a new FIP bias measure. A trend is found where coronae that
are IFIP biased in quiescence, during flares show a FIP bias with respect to
their quiescence composition. This effect is reversed for coronae that are FIP
biased in quiescence. The observed trend is thus consistent with chromospheric
evaporation rather than with a FIP mechanism operating during flares. It also
suggests that the quiescent IFIP bias is real and that the large flares are not
the direct cause of the IFIP effect in stellar coronae.


title:
Computational Complexity of interacting electrons and fundamental
  limitations of Density Functional Theory

abstract:
  One of the central problems in quantum mechanics is to determine the ground
state properties of a system of electrons interacting via the Coulomb
potential. Since its introduction by Hohenberg, Kohn, and Sham, Density
Functional Theory (DFT) has become the most widely used and successful method
for simulating systems of interacting electrons, making their original work one
of the most cited in physics. In this letter, we show that the field of
computational complexity imposes fundamental limitations on DFT, as an
efficient description of the associated universal functional would allow to
solve any problem in the class QMA (the quantum version of NP) and thus
particularly any problem in NP in polynomial time. This follows from the fact
that finding the ground state energy of the Hubbard model in an external
magnetic field is a hard problem even for a quantum computer, while given the
universal functional it can be computed efficiently using DFT. This provides a
clear illustration how the field of quantum computing is useful even if quantum
computers would never be built.


title: On the Analysis of Intermediate-Energy Coulomb Excitation Experiments

abstract:
  In a recent publication (Bertulani et al., PLB 650 (2007) 233 and
arXiv:0704.0060v2) the validity of analysis methods used for
intermediate-energy Coulomb excitation experiments was called into question.
Applying a refined theory large corrections of results in the literature seemed
needed. We show that this is not the case and that the large deviations
observed are due to the use of the wrong experimental parameters. We
furthermore show that an approximate expression derived by Bertulani et al. is
in fact equivalent to the theory of Winther and Alder (NPA 319 (1979) 518), an
analysis method often used in the literature.


title: Operation of a Thick Gas Electron Multiplier (THGEM) in Ar, Xe and Ar-Xe

abstract:
  We present the results of our recent studies of a Thick Gaseous Electron
Multiplier (THGEM)-based detector, operated in Ar, Xe and Ar:Xe (95:5) at
various gas pressures. Avalanche-multiplication properties and energy
resolution were investigated with soft x-rays for different detector
configurations and parameters. Gains above 10E4 were reached in a double-THGEM
detector, at atmospheric pressure, in all gases, in almost all the tested
conditions; in Ar:Xe (95:5) similar gains were reached at pressures up to 2
bar. The energy resolution dependence on the gas, pressure, hole geometry and
electric fields was studied in detail, yielding in some configurations values
below 20% FWHM with 5.9 keV x-rays.


title: Halos of Unified Dark Matter Scalar Field

abstract:
  We investigate the static and spherically symmetric solutions of Einstein's
equations for a scalar field with non-canonical kinetic term, assumed to
provide both the dark matter and dark energy components of the Universe. In
particular, we give a prescription to obtain solutions (dark halos) whose
rotation curve v_c(r) is in good agreement with observational data. We show
that there exist suitable scalar field Lagrangians that allow to describe the
cosmological background evolution and the static solutions with a single dark
fluid.


title: On the streamlines and particle paths of gravitational water waves

abstract:
  We investigate steady symmetric gravity water waves on finite depth. For
non-positive vorticity it is shown that the particles display a mean forward
drift, and for a class of waves we prove that the size of this drift is
strictly increasing from bottom to surface. We also provide detailed
information concerning the streamlines and the particle trajectories. This
includes the case of particles within irrotational waves.


title:
Indirect control with quantum accessor: coherent control by initial
  state preparation

abstract:
  This is the second one in our series of papers on indirect quantum control
assisted by quantum accessor. In this paper we propose and study a new class of
indirect quantum control(IDQC) scheme based on the initial states preparation
of the accessor. In the present scheme, after the initial state of the accessor
is properly prepared, the system is controlled by repeatedly switching on and
off the interaction between the system and the accessor. This is different from
the protocol of our first paper, where we manipulate the interaction between
the controlled system and the accessor. We prove the controllability of the
controlled system for the proposed indirect control scheme. Furthermore, we
give an example with two coupled spins qubits to illustrate the scheme, the
concrete control process and the controllability.


title:
Glauber dynamics on nonamenable graphs: Boundary conditions and mixing
  time

abstract:
  We study the stochastic Ising model on finite graphs with n vertices and
bounded degree and analyze the effect of boundary conditions on the mixing
time. We show that for all low enough temperatures, the spectral gap of the
dynamics with (+)-boundary condition on a class of nonamenable graphs, is
strictly positive uniformly in n. This implies that the mixing time grows at
most linearly in n. The class of graphs we consider includes hyperbolic graphs
with sufficiently high degree, where the best upper bound on the mixing time of
the free boundary dynamics is polynomial in n, with exponent growing with the
inverse temperature. In addition, we construct a graph in this class, for which
the mixing time in the free boundary case is exponentially large in n. This
provides a first example where the mixing time jumps from exponential to linear
in n while passing from free to (+)-boundary condition. These results extend
the analysis of Martinelli, Sinclair and Weitz to a wider class of nonamenable
graphs.


title:
Diffractive vector meson electroproduction at small Bjorken $x$ within
  GPD approach

abstract:
  We study light vector meson electroproduction at small $x$ within the
generalized parton distributions (GPDs) model. The modified perturbative
approach is used, where the quark transverse degrees of freedom in the vector
meson wave function and hard subprocess are considered. Our results on the
cross section and spin observables are in good agreement with experiment


title: Zitterbewegung by Quantum Field Theory Considerations

abstract:
  The validity of the work by Lamata et al [Phys. Rev. Lett. 98, 253005 (2007)]
can be further shown by quantum field theory considerations.


title: Integral means and boundary limits of Dirichlet series

abstract:
  We study the boundary behavior of functions in the Hardy spaces HD^p for
ordinary Dirichlet series. Our main result, answering a question of H.
Hedenmalm, shows that the classical F. Carlson theorem on integral means does
not extend to the imaginary axis for functions in HD^\infty, i.e., for ordinary
Dirichlet series in H^\infty of the right half-plane. We discuss an important
embedding problem for HD^p, the solution of which is only known when p is an
even integer. Viewing HD^p as Hardy spaces of the infinite-dimensional
polydisc, we also present analogues of Fatou's theorem.


title: Linear and nonlinear tails II: exact decay rates in spherical symmetry

abstract:
  We derive the exact late-time asymptotics for small spherically symmetric
solutions of nonlinear wave equations with a potential. The dominant tail is
shown to result from the competition between linear and nonlinear effects.


title:
Sharp Spectral Asymptotics for Dirac Energy. II. Magnetic Schroedinger
  operator

abstract:
  I derive sharp semiclassical asymptotics of \int |e_h(x,y,0)|^2\omega
(x,y)dxdy where e_h(x,y,\tau) is the Schwartz kernel of the spectral projector
of Magnetic Schroedinger operator and \omega (x,y) is singular as x=y. I also
consider asymptotics of more general expressions.


title: The "fireshell" model and the "canonical" GRB scenario

abstract:
  In the "fireshell" model we define a "canonical GRB" light curve with two
sharply different components: the Proper-GRB (P-GRB), emitted when the
optically thick fireshell of electron-positron plasma originating the
phenomenon reaches transparency, and the afterglow, emitted due to the
collision between the remaining optically thin fireshell and the CircumBurst
Medium (CBM). We outline our "canonical GRB" scenario, originating from the
gravitational collapse to a black hole, with a special emphasis on the
discrimination between "genuine" and "fake" short GRBs.


title:
Near-infrared evolution of brightest cluster galaxies in the most X-ray
  luminous clusters since z=1

abstract:
  We investigate the near infrared evolution of brightest cluster galaxies
(BCGs) from a sample of rich galaxy clusters since z=1. By employing an X-ray
selection of Lx>1e44 erg s-1 we limit environmental effects by selecting BCGs
in comparably high density regions. We find a positive relationship between
X-ray and near-infrared luminosity for BCGs in clusters with Lx>5e44 erg s-1.
Applying a correction for this relation we reduce the scatter in the BCG
absolute magnitude by a factor of 30%. The near-infrared J-K colour evolution
demonstrates that the stellar population in BCGs has been in place since at
least z=2 and that we expect a shorter period of star formation than that
predicted by current hierarchical merger models. We also confirm that there is
a relationship between `blue' J-K colour and the presence of BCG emission lines
associated with star formation in cooling flows.


title: De-contamination of cosmological 21-cm maps

abstract:
  We present a method for extracting the expected cosmological 21-cm signal
from the epoch of reionization, taking into account contaminating radiations
and random instrumental noise. The method is based on the maximum a-posteriori
probability (MAP) formalism and employs the coherence of the contaminating
radiation along the line-of-sight and the three-dimensional correlations of the
cosmological signal. We test the method using a detailed and comprehensive
modeling of the cosmological 21-cm signal and the contaminating radiation. The
signal is obtained using a high resolution N-body simulation where the gas is
assumed to trace the dark matter and is reionized by stellar radiation computed
from semi-analytic galaxy formation recipes. We model contaminations to the
cosmological signal from synchrotron and free-free galactic foregrounds and
extragalactic sources including active galactic nuclei, radio haloes and
relics, synchrotron and free-free emission from star forming galaxies, and
free-free emission from dark matter haloes and the intergalactic medium. We
provide tests of the reconstruction method for several rms values of
instrumental noise from $\sigma_{N}=1$ to 250 mK. For low instrumental noise,
the recovered signal, along individual lines-of-sight, fits the true
cosmological signal with a mean rms difference of $d_{rms}\approx 1.7\pm 0.6$
for $\sigma_{N}=1$ mK, and $d_{rms}\approx 4.2\pm 0.4$ for $\sigma_{N}=5$ mK.
The one-dimensional power spectrum is nicely reconstructed for all values of
$\sigma_{N}$ considered here, while the reconstruction of the two-dimensional
power spectrum and the Minkowski functionals is good only for noise levels of
the order of few mK.


title:
Measurement of the Strong Phase in D0 -> K+pi- Using Quantum
  Correlations

abstract:
  We exploit the quantum coherence between pair-produced D0 and D0bar in
psi(3770) decays to study charm mixing and to make a first measurement of the
relative strong phase \delta between D0 -> K+pi- and D0bar -> K+pi-. Using 281
pb^-1 of e+e- collision data collected with the CLEO-c detector at E_cm=3.77
GeV, as well as branching fraction input from other experiments, we make a
preliminary determination of \cos\delta = 1.03 +- 0.19 +- 0.08, where the
uncertainties are statistical and systematic, respectively. By further
including other external mixing parameter measurements, we obtain an alternate
measurement of \cos\delta = 0.93 +- 0.32 +- 0.04, where the systematic
uncertainty from assuming x\sin\delta=0 has not been included.


title: Simrank++: Query rewriting through link analysis of the click graph

abstract:
  We focus on the problem of query rewriting for sponsored search. We base
rewrites on a historical click graph that records the ads that have been
clicked on in response to past user queries. Given a query q, we first consider
Simrank as a way to identify queries similar to q, i.e., queries whose ads a
user may be interested in. We argue that Simrank fails to properly identify
query similarities in our application, and we present two enhanced version of
Simrank: one that exploits weights on click graph edges and another that
exploits ``evidence.'' We experimentally evaluate our new schemes against
Simrank, using actual click graphs and queries form Yahoo!, and using a variety
of metrics. Our results show that the enhanced methods can yield more and
better query rewrites.


title:
GRB 070724B: the first Gamma Ray Burst localized by SuperAGILE and its
  Swift X-ray Afterglow

abstract:
  GRB 070724B is the first Gamma Ray Burst localized by SuperAGILE, the hard
X-ray monitor aboard the AGILE satellite. The coordinates of the event were
published $\sim 19$ hours after the trigger. The Swift X-Ray Telescope pointed
at the SuperAGILE location and detected the X-ray afterglow inside the
SuperAGILE error circle. The AGILE gamma-ray Tracker and Minicalorimeter did
not detect any significant gamma ray emission associated with GRB 070724B in
the MeV and GeV range, neither prompt nor delayed. Searches of the optical
afterglow were performed by the Swift UVOT and the Palomar automated 60-inch
telescopes without any significant detection. Similarly the Very Large Array
did not detect a radio afterglow. This is the first GRB event with a firm upper
limit in the 100 MeV -- 30 GeV energy range, associated with an X-ray
afterglow.


title: A suggestion for B-10 imaging during boron neutron capture therapy

abstract:
  Selective accumulation of B-10 compound in tumour tissue is a fundamental
condition for the achievement of BNCT (Boron Neutron Capture Therapy), since
the effectiveness of therapy irradiation derives just from neutron capture
reaction of B-10. Hence, the determination of the B-10 concentration ratio,
between tumour and healthy tissue, and a control of this ratio, during the
therapy, are essential to optimise the effectiveness of the BNCT, which it is
known to be based on the selective uptake of B-10 compound. In this work,
experimental methods are proposed and evaluated for the determination in vivo
of B-10 compound in biological samples, in particular based on neutron
radiography and gammaray spectroscopy by telescopic system. Measures and Monte
Carlo calculations have been performed to investigate the possibility of
executing imaging of the 10B distribution, both by radiography with thermal
neutrons, using 6LiF/ZnS:Ag scintillator screen and a CCD camera, and by
spectroscopy, based on the revelation of gamma-ray reaction products from B-10
and the H. A rebuilding algorithm has been implemented. The present study has
been done for the standard case of B-10 uptake, as well as for proposed case in
which, to the same carrier, is also synthesized Gd-157, in the amount of is
used like a contrast agent in NMRI.


title: Photodetection in silicon beyond the band edge with surface states

abstract:
  Silicon is an extremely attractive material platform for integrated optics at
telecommunications wavelengths, particularly for integration with CMOS
circuits. Developing detectors and electrically pumped lasers at telecom
wavelengths are the two main technological hurdles before silicon can become a
comprehensive platform for integrated optics. We report on the generation of
free carriers in unimplanted SOI ridge waveguides, which we attribute to
surface state absorption. By electrically contacting the waveguides, a
photodetector with a responsivity of 36 mA/W and quantum efficiency of 2.8% is
demonstrated. The photoconductive effect is shown to have minimal falloff at
speeds of up to 60 Mhz.


title:
Flavor Changing Neutral Higgs Bosons in a Supersymmetric Extension based
  on a $Q_6$ Family Symmetry

abstract:
  A supersymmetric extension of the standard model based on the discrete $Q_6$
family symmetry is considered, and we investigate flavor-changing neutral
current (FCNC) processes, especially those mediated by heavy flavor-changing
neutral Higgs bosons. Because of the family symmetry the number of the
independent Yukawa couplings is smaller than that of the observed quantities
such as the Cabibbo-Kobayashi-Maskawa matrix and the quark masses, so that the
FCNCs can be parametrized only by the mixing angles and masses of the Higgs
fields. We focus our attention on the mass differences of the neutral $K, D$
and $B$ mesons. All the constraints including that from the ratio $\Delta
M_{B_s}/\Delta M_{B_d}$ can be satisfied, if the heavy Higgs bosons are heavier
than $\sim 1.5$ TeV. If the constraint from $\Delta M_K$ is slightly relaxed,
the heavy Higgs bosons can be as light as $\sim 0.4$ TeV, which is within the
accessible range of LHC.


title:
Microscopic Mechanism and Pairing Symmetry of Superconductivity in the
  Noncentrosymmetric Heavy Fermion Systems CeRhSI$_3$ and CeIrSi$_3$

abstract:
  We study the pairing symmetry of the noncentrosymmetric heavy fermion
superconductors CeRhSi$_3$ and CeIrSi$_3$ under pressures, which are both
antiferromagnets at ambient pressure. We solve the Eliashberg equation by means
of the random phase approximation and find that the mixed state of extended
s-wave and p-wave rather than the $d+f$ wave state could be realized by
enhanced antiferromagnetic spin fluctuations. It is elucidated that the gap
function has line nodes on the Fermi surface and the resulting density of state
in the superconducting state shows a similar character to that of usual d-wave
superconductors, resulting in the NMR relaxation rate $1/(T_1T)$ that exhibits
no coherence peak and behaves like $1/(T_1T)\propto T^2$ at low temperatures.


title: Photonic portal to the sterile world of cold dark matter

abstract:
  We assume that the cold dark matter consists of spin-1/2 and spin-0 particles
described by a bispinor field \psi and a scalar field \phi, sterile from all
Standard Model charges (in contrast, neutralinos, supersymmetric candidates for
cold dark matter, are not sterile from weak Standard Model charges). We
propose, however, that such a sterile world can contact with our Standard Model
world not only through gravity but also through a portal provided by photons
coupled to sterile particles by means of two very weak effective interactions
-(f/M^2)\phi F^{\mu\nu}\phi F_{\mu\nu} and -(f'/M^2) (\bar\psi \sigma^{\mu\nu}
\psi)\phi F_{\mu\nu}, where M is a very large mass scale and f and f' are
dimensionless coupling constants. Thus, in our picture, the electromagnetic
field F_{\mu\nu} - as the only Standard Model field - participates in both
worlds, providing a nongravitational link between them (other than the popular
supersymmetric weak interaction, active in the case of neutralinos). In
consequence, there appears a tiny quasi-magnetic correction to the conventional
electromagnetic current (described in Appendix A).


title: Seiberg--Witten Maps to All Orders

abstract:
  All order Seiberg--Witten maps of gauge parameter, gauge field and matter
fields are given as a closed recursive formula. These maps are obtained by
analyzing the order by order solutions of the gauge consistency and equivalence
conditions as well as by directly solving Seiberg-Witten differential
equations. The explicit third order non-abelian and fourth order abelian
Seiberg-Witten maps of gauge parameter and gauge field are also presented.


title: Rational Extensions of C(X) via Hausdorff Continuous Functions

abstract:
  The ring operations and the metric on $C(X)$ are extended to the set
$\mathbb{H}_{nf}(X)$ of all nearly finite Hausdorff continuous interval valued
functions and it is shown that $\mathbb{H}_{nf}(X)$ is both rationally and
topologically complete. Hence, the rings of quotients of $C(X)$ as well as
their metric completions are represented as rings of Hausdorff continuous
functions.


title:
Diffusive-Ballistic Transition in Random Walks with Long-Range
  Self-Repulsion

abstract:
  We prove that a class of random walks on $\Z^2$ with long-range
self-repulsive interactions have a diffusive-ballistic phase transition.


title:
Universal behavior of baryons and mesons transverse momentum
  distributions in the framework of percolation of strings

abstract:
  In the framework of percolation of strings, the transverse momentum
distributions in AA and hh collisions at all centralities and energies follow a
universal behavior. The width of these distributions is related to the width of
the distribution of the size of the clusters formed from the overlapping of the
produced strings. The difference between the distributions for baryons and
mesons originates in the fragmentation of clusters of several strings which
enhance the particles with higher number of constituents. The results agree
with SPS and RHIC data. The predictions for LHC show differences for baryons
compared with RHIC. At LHC energies we obtain also a high pt suppression for pp
high multiplicity events compared with pp minimum bias.


title:
A Three-Dimensional Picture of the Delayed-Detonation Model of Type Ia
  Supernovae

abstract:
  Deflagration models poorly explain the observed diversity of SNIa. Current
multidimensional simulations of SNIa predict a significant amount of, so far
unobserved, carbon and oxygen moving at low velocities. It has been proposed
that these drawbacks can be resolved if there is a sudden jump to a detonation
(delayed detonation), but this kind of models has been explored mainly in one
dimension. Here we present new three-dimensional delayed detonation models in
which the deflagraton-to-detonation transition (DDT) takes place in conditions
like those favored by one-dimensional models. We have used a SPH code adapted
to SNIa with algorithms devised to handle subsonic as well as supersonic
combustion fronts. The starting point was a C-O white dwarf of 1.38 solar
masses. When the average density on the flame surface reached 2-3x10^7 g/cm^3 a
detonation was launched. The detonation wave processed more than 0.3 solar
masses of carbon and oxygen, emptying the central regions of the ejecta of
unburned fuel and raising its kinetic energy close to the fiducial 10^51 ergs
expected from a healthy Type Ia supernova. The final amount of 56Ni synthesized
also was in the correct range. However, the mass of carbon and oxygen ejected
is still too high. The three-dimensional delayed detonation models explored
here show an improvement over pure deflagration models, but they still fail to
coincide with basic observational constraints. However, there are many aspects
of the model that are still poorly known (geometry of flame ignition, mechanism
of DDT, properties of detonation waves traversing a mixture of fuel and ashes).
Therefore, it will be worth pursuing its exploration to see if a good SNIa
model based on the three-dimensional delayed detonation scenario can be
obtained.


title:
Accurate Quantitative Spectroscopy of OB Stars: C and N abundances near
  the Main Sequence

abstract:
  We present a state-of-the-art analysis technique able to simultaneously
reproduce the entire H and He spectra of OB-type stars in the visual and the
near-IR and to derive highly accurate metal abundances (so far C and N). The
spectrum synthesis relies on a hybrid non-LTE approach involving our most
recent model atoms. Accurate atmospheric parameters, with reduced systematic
errors, are derived spectroscopically (from Stark-broadened H lines and
ionization equilibria of He I/II and C II-IV) for a sample of randomly
distributed stars in the solar vicinity. Highly consistent abundances are found
in contrast to previous reports indicating broad scatter and large
uncertainties. The improvements result from avoidance of systematic errors in
the parameter determination, which may be larger than expected in previous
work, and a critical evaluation of atomic data for the model atom construction.


title: Nested Subgraphs of Complex Networks

abstract:
  We analytically explore the scaling properties of a general class of nested
subgraphs in complex networks, which includes the $K$-core and the
$K$-scaffold, among others. We name such class of subgraphs $K$-nested
subgraphs due to the fact that they generate families of subgraphs such that
$...S_{K+1}({\cal G})\subseteq S_K({\cal G})\subseteq S_{K-1}({\cal G})...$.
Using the so-called {\em configuration model} it is shown that any family of
nested subgraphs over a network with diverging second moment and finite first
moment has infinite elements (i.e. lacking a percolation threshold). Moreover,
for a scale-free network with the above properties, we show that any nested
family of subgraphs is self-similar by looking at the degree distribution. Both
numerical simulations and real data are analyzed and display good agreement
with our theoretical predictions.


title: Newhouse phenomenon and homoclinic classes

abstract:
  We show that for a $C^1$ residual subset of diffeomorphisms far away from
tangency, every non-trivial chain recurrent class that is accumulated by
sources ia a homoclinic class contains periodic points with index 1 and it's
the Hausdorff limit of a family of sources.


title: Lyapunov stable chain recurrent classes

abstract:
  We show that for a $C^1$ residual subset of diffeomorphisms far away from
homoclinic tangency, the stable manifolds of periodic points cover a dense
subset of the ambient manifold. This gives a partial proof to a conjecture of
C. Bonatti.


title:
Normal Globular Cluster Systems in Massive Low Surface Brightness
  Galaxies

abstract:
  We present the results of a study of the globular cluster systems of 6
massive spiral galaxies, originally cataloged as low surface brightness
galaxies but here shown to span a wide range of central surface brightness
values, including two intermediate to low surface brightness galaxies. We used
the Advanced Camera for Surveys on board HST to obtain photometry in the F475W
and F775W bands and select sources with photometric and morphological
properties consistent with those of globular clusters. A total of 206
candidates were identified in our target galaxies. From a direct comparison
with the Galactic globular cluster system we derive specific frequency values
for each galaxy that are in the expected range for late-type galaxies. We show
that the globular cluster candidates in all galaxies have properties consistent
with globular cluster systems of previously studied galaxies in terms of
luminosity, sizes and color. We establish the presence of globular clusters in
the two intermediate to low surface brightness galaxies in our sample and show
that their properties do not have any significant deviation from the behavior
observed in the other sample galaxies. Our results are broadly consistent with
a scenario in which low surface brightness galaxies follow roughly the same
evolutionary history as normal (i.e. high surface) brightness galaxies except
at a much lower rate, but require the presence of an initial period of star
formation intense enough to allow the formation of massive star clusters.


title: Relativistic Hamiltonian Dynamics and Few-Nucleon Systems

abstract:
  We present a preliminary calculation of the electromagnetic form factors of
$^3$He and $^3$H, performed within the Light-Front Hamiltonian Dynamics.
Relativistic effects show their relevance even at the static limit, increasing
at higher values of momentum transfer, as expected.


title: Recent developments in quantum key distribution: theory and practice

abstract:
  Quantum key distribution is among the foremost applications of quantum
mechanics, both in terms of fundamental physics and as a technology on the
brink of commercial deployment. Starting from principal schemes and initial
proofs of unconditional security for perfect systems, much effort has gone into
providing secure schemes which can cope with numerous experimental
imperfections unavoidable in real world implementations. In this paper, we
provide a comparison of various schemes and protocols. We analyse their
efficiency and performance when implemented with imperfect physical components.
We consider how experimental faults are accounted for using effective
parameters. We compare various protocols and provide guidelines as to which
components propose best advances when being improved.


title:
The Tremaine-Weinberg method for pattern speeds using H-alpha emission
  from ionized gas

abstract:
  The Fabry-Perot interferometer FaNTOmM was used at the 3.6m Canada France
Hawaii Telescope and the 1.6m Mont Megantic Telescope to obtain data cubes in
H-alpha of 9 nearby spiral galaxies from which maps in integrated intensity,
velocity, and velocity dispersion were derived. We then applied the
Tremaine-Weinberg method, in which the pattern speed can be deduced from its
velocity field, by finding the integrated value of the mean velocity along a
slit parallel to the major axis weighted by the intensity and divided by the
weighted mean distance of the velocity points from the tangent point measured
along the slit. The measured variables can be used either to make separate
calculations of the pattern speed and derive a mean, or in a plot of one
against the other for all the points on all slits, from which a best fit value
can be derived. Linear fits were found for all the galaxies in the sample. For
two galaxies a clearly separate inner pattern speed with a higher value, was
also identified and measured.


title: Magnetic structure and phase diagram of TmB4

abstract:
  Magnetic structure of single crystalline TmB4 has been studied by
magnetization, magnetoresistivity and specific heat measurements. A complex
phase diagram with different antiferromagnetic (AF) phases was observed below
TN1 = 11.7 K. Besides the plateau at half-saturated magnetization (1/2 MS),
also plateaus at 1/9, 1/8 and 1/7 of MS were observed as function of applied
magnetic field B//c. From additional neutron scattering experiments on TmB4, we
suppose that those plateaus arise from a stripe structure which appears to be
coherent domain boundaries between AF ordered blocks of 7 or 9 lattice
constants. The received results suggest that the frustration among the Tm3+
magnetic ions, which maps to a geometrically frustrated Shastry-Sutherland
lattice lead to strong competition between AF and ferromagnetic (FM) order.
Thus, stripe structures in intermediate field appear to be the best way to
minimize the magnetostatic energy against other magnetic interactions between
the Tm ions combined with very strong Ising anisotropy.


title: From Quantum Universal Enveloping Algebras to Quantum Algebras

abstract:
  The ``local'' structure of a quantum group G_q is currently considered to be
an infinite-dimensional object: the corresponding quantum universal enveloping
algebra U_q(g), which is a Hopf algebra deformation of the universal enveloping
algebra of a n-dimensional Lie algebra g=Lie(G). However, we show how, by
starting from the generators of the underlying Lie bialgebra (g,\delta), the
analyticity in the deformation parameter(s) allows us to determine in a unique
way a set of n ``almost primitive'' basic objects in U_q(g), that could be
properly called the ``quantum algebra generators''. So, the analytical
prolongation (g_q,\Delta) of the Lie bialgebra (g,\delta) is proposed as the
appropriate local structure of G_q. Besides, as in this way (g,\delta) and
U_q(g) are shown to be in one-to-one correspondence, the classification of
quantum groups is reduced to the classification of Lie bialgebras. The su_q(2)
and su_q(3) cases are explicitly elaborated.


title:
Bernoulli coding map and almost sure invariance principle for
  endomorphisms of $\mathbb{P}^k$

abstract:
  Let $f$ be an holomorphic endomorphism of $\mathbb{P}^k$ and $\mu$ be its
measure of maximal entropy. We prove an Almost Sure Invariance Principle for
the systems $(\mathbb{P}^k,f,\mu)$. Our class $\cal{U}$ of observables includes
the H\"older functions and unbounded ones which present analytic singularities.
The proof is based on a geometric construction of a Bernoulli coding map
$\omega: (\Sigma, s, \nu) \to (\mathbb{P}^k,f,\mu)$. We obtain the invariance
principle for an observable $\psi$ on $(\mathbb{P}^k,f,\mu)$ by applying
Philipp-Stout's theorem for $\chi = \psi \circ \omega$ on $(\Sigma, s, \nu)$.
The invariance principle implies the Central Limit Theorem as well as several
statistical properties for the class $\cal{U}$. As an application, we give a
\emph{direct} proof of the absolute continuity of the measure $\mu$ when it
satisfies Pesin's formula. This approach relies on the Central Limit Theorem
for the unbounded observable $\log \textsf{Jac} f \in \cal{U}$.


title: K-spectral sets and intersections of disks of the Riemann sphere

abstract:
  We prove that if two closed disks X_1 and X_2 of the Riemann sphere are
spectral sets for a bounded linear operator A on a Hilbert space, then the
intersection X_1\cap X_2 is a complete (2+2/\sqrt{3})-spectral set for A. When
the intersection of X_1 and X_2 is an annulus, this result gives a positive
answer to a question of A.L. Shields (1974).


title: Early Growth of Massive Black Holes in Quasars

abstract:
  Episodic activity of quasars is driving growth of supermassive black holes
(SMBHs) via accretion of baryon gas. In this Letter, we develop a simple method
to analyse the duty cycle of quasars up to redshift $z\sim 6$ universe from
luminosity functions (LFs). We find that the duty cycle below redshift $z\sim
2$ follows the cosmic history of star formation rate (SFR) density. Beyond
$z\sim 2$, the evolutionary trends of the duty cycle are just opposite to that
of the cosmic SFR density history, implying the role of feedback from black
hole activity. With the duty cycle, we get the net lifetime of quasars ($z\le
5$) about $\sim 10^9$yrs. Based on the local SMBHs, the mean mass of SMBHs is
obtained at any redshifts and their seeds are of $10^5\sunm$ at the
reionization epoch ($z_{\rm re}$) of the universe through the conservation of
the black hole number density in comoving frame. We find that primordial black
holes ($\sim 10^3\sunm$) are able to grow up to the seeds via a moderate
super-Eddington accretion of $\sim 30$ times of the critical rate from $z=24$
to $z_{\rm re}$. Highly super-Eddington accretion onto the primordials is not
necessary.


title: The record-breaking rotational braking of the He strong CP star HD 37776

abstract:
  We study the long-term light and spectral variations in the He-strong
magnetic chemically peculiar star HD 37776 (V901 Ori) to search for changes of
its 1.5387 d period in 1976-2007. We analyze all published photometric
observations and spectrophotometry in the HeI 4026 A line. The data were
supplmented with 506 new (U)VB observations obtained during the last 2
observing seasons, 66 estimates of HeI equivalent widths on 23 CFHT
spectrograms and 35 of the 6-m Zeeman spectrograms. All the 1895 particular
observations heve been processed simultaneously. We confirm the previously
suspected increase of the period in HD 37776 which is a record-breaking among
CP stars. The mean rate of the period increase during the last 31 years is
0.541+-0.020 s per year. We interpret this ongoing period increase as the
slowing down of the star's surface rotation due to momentum loss through events
and processes in its magnetosphere.


title: Comparing Gr\"obner bases and word reversing

abstract:
  Gr\"obner bases, in their noncommutative version, and word reversing are
methods for solving the word problem of a presented monoid, and both rely on
iteratively completing the initial list of relations. Simple examples may
suggest to conjecture that both completion procedures are closely related. Here
we disprove this conjecture by exhibiting families of presentations for which
they radically differ.


title:
MSbar quark distribution and dipole scattering matrix elements at high
  energy

abstract:
  We discuss the operator relation that connects the renormalized quark
distribution in the MSbar scheme with the Wilson-line correlator representing
dipole scattering in the s-channel picture.


title:
Large deviations for return times in non-rectangle sets for axiom A
  diffeomorphisms

abstract:
  For Axiom A diffeomorphisms and equilibrium states, we prove a Large
deviations result for the sequence of successive return times into a fixed
Borel set, under some assumption on the boundary. Our result relies on and
extends the work by Chazottes and Leplaideur who considered cylinder sets of a
Markov partition.


title:
${\cal T}$-class algorithms for pseudocontractions and $\kappa$-strict
  pseudocontractions in Hilbert spaces

abstract:
  In this paper we study iterative algorithms for finding a common element of
the set of fixed points of $\kappa$-strict pseudocontractions or finding a
solution of a variational inequality problem for a monotone, Lipschitz
continuous mapping. The last problem being related to finding fixed points of
pseudocontractions. These algorithms were already studied in [G.L. Acedo, H.-K.
Xu] and [N. Nadezhkina, W. Takahashi] but our aim here is to provide the links
between these know algorithms and the general framework of ${\cal T}$-class
algorithms studied in [H.H. Bauschke, P.L. Combettes].


title: Light Hadron Spectrum in the Instanton Liquid Model

abstract:
  We review our recent study of the role played by the chiral interactions
induced by instantons, in the lowest-lying sector of the light hadron spectrum.
We discuss how the ordering of the lowest meson and baryon excitations is
explained by the structure of the instanton-induced quark-quark and gluon-gluon
interaction. We focus on the pion, nucleon, vector- and axial-vector mesons,
and on the scalar glueball. We find that all these hadrons are bound in this
model and have realistic masses.


title: Symmetry-broken crystal structure of elemental boron at low temperature

abstract:
  The crystal structure of boron is unique among chemical elements, highly
complex, and imperfectly known. Experimentalists report the beta-rhombohedral
(black) form is stable over all temperatures from absolute zero to melting.
However, early calculations found its energy to be greater than the energy of
the alpha-rhombohedral (red) form, implying beta cannot be stable at low
temperatures. Furthermore, beta exhibits partially occupied sites, seemingly in
conflict with the thermodynamic requirement that entropy vanish at low
temperature. Using electronic density functional theory methods and an
extensive search of the configuration space we find a unique, energy minimizing
pattern of occupied and vacant sites that can be stable at low temperatures but
that breaks the beta-rhombohedral symmetry. Even lower energies occur within
larger unit cells. Alternative configurations lie nearby in energy, allowing
the entropy of partial occupancy to stabilize the beta-rhombohedral structure
through a phase transition at moderate temperature.


title:
Prostate biopsies guided by three-dimensional real-time (4-D)
  transrectal ultrasonography on a phantom: comparative study versus
  two-dimensional transrectal ultrasound-guided biopsies

abstract:
  OBJECTIVE: This study evaluated the accuracy in localisation and distribution
of real-time three-dimensional (4-D) ultrasound-guided biopsies on a prostate
phantom. METHODS: A prostate phantom was created. A three-dimensional real-time
ultrasound system with a 5.9MHz probe was used, making it possible to see
several reconstructed orthogonal viewing planes in real time. Fourteen
operators performed biopsies first under 2-D then 4-D transurethral ultrasound
(TRUS) guidance (336 biopsies). The biopsy path was modelled using segmentation
in a 3-D ultrasonographic volume. Special software was used to visualise the
biopsy paths in a reference prostate and assess the sampled area. A comparative
study was performed to examine the accuracy of the entry points and target of
the needle. Distribution was assessed by measuring the volume sampled and a
redundancy ratio of the sampled prostate. RESULTS: A significant increase in
accuracy in hitting the target zone was identified using 4-D ultrasonography as
compared to 2-D. There was no increase in the sampled volume or improvement in
the biopsy distribution with 4-D ultrasonography as compared to 2-D.
CONCLUSION: The 4-D TRUS guidance appears to show, on a synthetic model, an
improvement in location accuracy and in the ability to reproduce a protocol.
The biopsy distribution does not seem improved.


title: Poincare recurrences from the perspective of transient chaos

abstract:
  We obtain a description of the Poincar\'e recurrences of chaotic systems in
terms of the ergodic theory of transient chaos. It is based on the equivalence
between the recurrence time distribution and an escape time distribution
obtained by leaking the system and taking a special initial ensemble. This
ensemble is atypical in terms of the natural measure of the leaked system, the
conditionally invariant measure. Accordingly, for general initial ensembles,
the average recurrence and escape times are different. However, we show that
the decay rate of these distributions is always the same. Our results remain
valid for Hamiltonian systems with mixed phase space and validate a split of
the chaotic saddle in hyperbolic and non-hyperbolic components.


title: Spitzer photometry of discrete sources in M33

abstract:
  Combining the relative vicinity of the Local Group spiral galaxy M33 with the
Spitzer images, we investigate the properties of infrared (IR) emission sites
and assess the reliability of the IR emission as a star formation tracer. We
compared the photometric results for several samples of three known types of
discrete sources (HII regions, supernovae remnants and planetary nebulae) with
theoretical diagnostic diagrams, and derived the spectral energy distribution
(from 3.6 to 24 microns) of each type of object. Moreover, we generated a
catalogue of 24 microns sources and inferred their nature from the observed and
theoretical colours of the known type sources. We estimated the star formation
rate in M33 both globally and locally, from the IR emission and from the Halpha
emission line.


title: Quantum thermodynamic processes: A control theory for machine cycles

abstract:
  The minimal set of thermodynamic control parameters consists of a statistical
(thermal) and a mechanical one. These suffice to introduce all the pertinent
thermodynamic variables; thermodynamic processes can then be defined as paths
on this 2-dimensional control plane. Putting aside coherence we show that for a
large class of quantum objects with discrete spectra and for the cycles
considered the Carnot efficiency applies as a universal upper bound. In the
dynamic (finite time) regime renormalized thermodynamic variables allow to
include non-equilibrium phenomena in a systematic way. The machine function
ceases to exist in the large speed limit; the way, in which this limit is
reached, depends on the type of cycle considered.


title: The Robustness of n_s < 0.95 in Racetrack Inflation

abstract:
  A spectral index n_s < 0.95 appears to be a generic prediction of racetrack
inflation models. Reducing a general racetrack model to a single-field
inflation model with a simple potential, we obtain an analytic expression for
the spectral index, which explains this result. By considering the limits of
validity of the derivation, possible ways to achieve higher values of the
spectral index are described, although these require further fine-tuning of the
potential.


title: Dynamical Influence of Bars on the Star Formation in Isolated Galaxies

abstract:
  Star formation depends strongly on both the local environment of galaxies and
the internal dynamics of the interstellar medium. To disentangle the two
effects, we obtained, in the framework of the AMIGA project, Halpha and Gunn r
photometric data for more than 200 spiral galaxies lying in very low-density
regions of the local Universe. We characterise the Halpha emission, tracing
current star formation, of the 45 largest and least inclined galaxies observed
for which we estimate the torques between the gas and the bulk of the optical
matter. We subsequently study the Halpha morphological aspect of these isolated
spiral galaxies. Using Fourier analysis, we focus on the modes of the spiral
arms and also on the strength of the bars, computing the torques between the
gas and newly formed stars (Halpha), and the bulk of the optical matter (Gunn
r).


title:
Modified spontaneous symmetry breaking pattern by brane-bulk interaction
  terms

abstract:
  We show how translational invariance can be broken by the vacuum that drives
the spontaneous symmetry breaking of extra-dimensional extensions of the
Standard Model, when delta-like interactions between brane and bulk scalar
fields are present. We explicitly build some examples of vacuum configurations,
which induce the spontaneous symmetry breaking, and have non trivial profile in
the extra coordinate.


title: Detectable Signatures of Cosmic Radiative Feedback

abstract:
  We use a semi-analytical model to study the impact of reionization, and the
associated radiative feedback, on galaxy formation. Two feedback models have
been considered: (i) a standard prescription, according to which star formation
is totally suppressed in galaxies with circular velocity below a critical
threshold (model CF06) and (ii) a characterization based on the filtering scale
(model G00), allowing for a gradual reduction of the gas available for star
formation in low-mass galaxies. In model CF06 reionization starts at z ~ 15-20,
is 85% complete by z ~ 10; at the same z, the ionized fraction is 16% in model
G00. The models match SDSS constraints on the evolution of the neutral hydrogen
fraction at z < 7, but predict different Thomson optical depths, tau_e = 0.1017
(CF06), and 0.0631 (G00); such values are within 1 sigma of the WMAP 3-yr
determination. Both models are in remarkable good agreement with additional
existing data (evolution of Lyman-limit systems, cosmic star formation history,
high-z galaxy counts, IGM thermal history), which therefore cannot be used to
discriminate among different feedback models. Deviations among radiative
feedback prescriptions emerge when considering the expected HI 21 cm background
signal, where a ~ 15 mK absorption feature in the range 75-100 MHz is present
in model G00 and a global shift of the emission feature preceding reionization
towards larger frequencies occurs in the same model. Single dish observations
with existing or forthcoming low-frequency radio telescopes can achieve mK
sensitivity, allowing the identification of these features provided that
foregrounds can be accurately subtracted.


title: Electrostatics in a wormhole geometry

abstract:
  We determine in closed form the electrostatic potential generated by a point
charge at rest in a simple model of static spherically symmetric wormhole. From
this, we deduce the electrostatic self-energy of this point charge.


title:
Impact of double-logarithmic electroweak radiative corrections on the
  non-singlet structure functions at small x

abstract:
  In the QCD context, the non-singlet structure functions of u and d -quarks
are identical, save the initial quark densities. Electroweak radiative
corrections, being flavor-dependent, bring further difference between the
non-singlets. This difference is calculated in the double-logarithmic
approximation and the impact of the electroweak corrections on the non-singlet
intercepts is estimated numerically.


title: New Construction of A Family of Quasi-Twisted Two-Weight Codes

abstract:
  Based on cyclic and consta-cyclic simplex codes, a new explicit construction
of a family of two-weight codes is presented. These two-weight codes obtained
are in the form of 2-generator quasi-cyclic, or quasi-twisted structure. Based
on this construction, new optimal binary quasi-cyclic [195, 8, 96], [210, 8,
104] and [240, 8, 120] codes, and good QC ternary [208, 6, 135] and [221, 6,
144] codes are thus obtained. It is also shown that many codes among the family
meet the Griesmer bound and thereful are optimal.


title: Killing-Yano equations and G-structures

abstract:
  We solve the Killing-Yano equation on manifolds with a $G$-structure for
$G=SO(n), U(n), SU(n), Sp(n)\cdot Sp(1), Sp(n), G_2$ and $Spin(7)$. Solutions
include nearly-K\"ahler, weak holonomy $G_2$, balanced SU(n) and holonomy $G$
manifolds. As an application, we find that particle probes on $AdS_4\times X$
compactifications of type IIA and 11-dimensional supergravity admit a ${\cal
W}$-type of symmetry generated by the fundamental forms. We also explore the
${\cal W}$-symmetries of string and particle actions in heterotic and common
sector supersymmetric backgrounds. In the heterotic case, the generators of the
${\cal W}$-symmetries completely characterize the solutions of the gravitino
Killing spinor equation, and the structure constants of the ${\cal W}$-symmetry
algebra depend on the solution of the dilatino Killing spinor equation.


title:
A giant radio jet ejected by an ultramassive black hole in a
  single-lobed radio galaxy

abstract:
  We report the discovery of a very unusual, highly asymmetric radio galaxy
whose radio jet, the largest yet detected, emits strongly polarized synchrotron
radiation and can be traced all the way from the galactic nucleus to the hot
spot located ~440 kpc away. This jet emanates from an extremely massive black
hole (>10^9 solar mass) and forms a strikingly compact radio lobe. No radio
lobe is detected on the side of the counterjet, even though it is similar to
the main jet in brightness up to a scale of tens of kiloparsecs. Thus, contrary
to the nearly universal trend, the brightness asymmetry in this radio galaxy
increases with distance from the nucleus. With several unusual properties,
including a predominantly toroidal magnetic field, this Fanaroff-Riley type II
megajet is an exceptionally useful laboratory for testing the role of magnetic
field in jet stabilization and radio lobe formation.


title: Wigner-Cusp in Kaon Decays and Determination of pi pi Scattering Lengths

abstract:
  In the last few years it has become possible to study low energy pi pi
scattering in kaon decays to three pions, thanks to the high statistics
measurement of K+- -> pi+- pi0 pi0 decays performed by the NA48/2 experiment at
the CERN SPS. At the pi+ pi- threshold, the pi0 pi0 mass spectrum exhibits a
Wigner-cusp, from which the S-wave pi pi scattering lengths are extracted with
high precision. This measurement is complementary to the extraction of the
scattering lengths from K_e4 decays, which is also performed by the NA48/2
experiment.


title: Regulative Differentiation as Bifurcation of Interacting Cell Population

abstract:
  In multicellular organisms, several cell states coexist. For determining each
cell type, cell-cell interactions are often essential, in addition to
intracellular gene expression dynamics. Based on dynamical systems theory, we
propose a mechanism for cell differentiation with regulation of populations of
each cell type by taking simple cell models with gene expression dynamics. By
incorporating several interaction kinetics, we found that the cell models with
a single intracellular positive-feedback loop exhibit a cell fate switching,
with a change in the total number of cells. The number of a given cell type or
the population ratio of each cell type is preserved against the change in the
total number of cells, depending on the form of cell-cell interaction. The
differentiation is a result of bifurcation of cell states via the intercellular
interactions, while the population regulation is explained by self-consistent
determination of the bifurcation parameter through cell-cell interactions. The
relevance of this mechanism to development and differentiation in several
multicellular systems is discussed.


title:
Low-Energy Effective Theory, Unitarity, and Non-Decoupling Behavior in a
  Model with Heavy Higgs-Triplet Fields

abstract:
  We discuss the properties of a model incorporating both a scalar electroweak
Higgs doublet and an electroweak Higgs triplet. We construct the low-energy
effective theory for the light Higgs-doublet in the limit of small (but
nonzero) deviations in the rho parameter from one, a limit in which the triplet
states become heavy. For small deviations in the rho parameter from one,
perturbative unitarity of WW scattering breaks down at a scale inversely
proportional to the renormalized vacuum expectation value of the triplet field
(or, equivalently, inversely proportional to the square-root of the deviation
of the rho parameter from one). This result imposes an upper limit on the
mass-scale of the heavy triplet bosons in a perturbative theory; we show that
this upper bound is consistent with dimensional analysis in the low-energy
effective theory. Recent articles have shown that the triplet bosons do not
decouple, in the sense that deviations in the rho parameter from one do not
necessarily vanish at one-loop in the limit of large triplet mass. We clarify
that, despite the non-decoupling behavior of the Higgs-triplet, this model does
not violate the decoupling theorem since it incorporates a large dimensionful
coupling. Nonetheless, we show that if the triplet-Higgs boson masses are of
order the GUT scale, perturbative consistency of the theory requires the
(properly renormalized) Higgs-triplet vacuum expectation value to be so small
as to be irrelevant for electroweak phenomenology.


title:
On the role of the far fields and of cosmology for the theory of
  gravitation and for the dark matter problem

abstract:
  We give an estimate of the gravitational field of force exerted on a test
particle by the far galaxies, in the frame of the weak field approximation. In
virtue of Hubble's law, the action of the far matter turns out to be non
negligible, and even the dominant one. An extremely simplified cosmological
model is considered. A nonvanishing contribution is obtained only if the
discrete and fractal nature of the matter distribution is taken into account.
The force per unit mass acting on a test particle is found to be of the order
of $0.2 cH_0$, where $c$ is the speed of light and $H_0$ the present value of
Hubble's constant.


title:
Microwave excitations associated with a wavy angular dependence of the
  spin transfer torque : model and experiments

abstract:
  The spin transfer torque (STT) can lead to steady precession of magnetization
without any external applied field in magnetic spin valve where the magnetic
layer have very different spin diffusion length. This effect is associated with
an unusual angular dependence of the STT, called "wavy" (WAD-STT), predicted in
the frame of diffusive models of spin transfer. In this article, we present a
complete experimental characterization of the magnetization dynamics in the
presence of a WAD-STT. The results are compared to the prediction of the
magnetization dynamics obtained by single domain magnetic simulations
(macrospin approximation). The macrospin simulations well reproduced the main
static and dynamical experimental features (phase diagram, R(I) curves,
dependence of frequency with current and field) and suggest that the dynamical
excitations observed experimentally are associated with a large angle
out-of-plane precession mode. The present work validates the diffusive models
of the spin transfer and underlines the role of the spin accumulation and the
spin relaxation effects on the STT.


title: Asymptotic analysis of the Skyrmed monopole

abstract:
  We consider a variant of the Georgi Glashow model in the BPS limit, augmented
by a higher derivative Skyrme-like term, which is the simplest YMH model that
can support monopole bound states. The spherically symetric solutions are
studied with a combination of analytic and numerical techniques, which strongly
suggest that the solutions converge to a finite energy configuration in the
limit of infinite coupling of the Skyrme-like term.


title:
GRB970228 and the class of GRBs with an initial spikelike emission: do
  they follow the Amati relation?

abstract:
  On the basis of the recent understanding of GRB050315 and GRB060218, we
return to GRB970228, the first Gamma-Ray Burst (GRB) with detected afterglow.
We proposed it as the prototype for a new class of GRBs with "an occasional
softer extended emission lasting tenths of seconds after an initial spikelike
emission". Detailed theoretical computation of the GRB970228 light curves in
selected energy bands for the prompt emission are presented and compared with
observational BeppoSAX data. From our analysis we conclude that GRB970228 and
likely the ones of the above mentioned new class of GRBs are "canonical GRBs"
have only one peculiarity: they exploded in a galactic environment, possibly
the halo, with a very low value of CBM density. Here we investigate how
GRB970228 unveils another peculiarity of this class of GRBs: they do not
fulfill the "Amati relation". We provide a theoretical explanation within the
fireshell model for the apparent absence of such correlation for the GRBs
belonging to this new class.


title: Diffusion in the Markovian limit of the spatio-temporal colored noise

abstract:
  We explore the diffusion process in the non-Markovian spatio-temporal
noise.%the escape rate problem in the non-Markovian spatio-temporal random
noise. There is a non-trivial short memory regime, i.e., the Markovian limit
characterized by a scaling relation between the spatial and temporal
correlation lengths. In this regime, a Fokker-Planck equation is derived by
expanding the trajectory around the systematic motion and the non-Markovian
nature amounts to the systematic reduction of the potential. For a system with
the potential barrier, this fact leads to the renormalization of both the
barrier height and collisional prefactor in the Kramers escape rate, with the
resultant rate showing a maximum at some scaling limit.


title: A simplified multidimensional integral

abstract:
  We present a simplified integral of functions of several variables. Although
less general than the Riemann integral, most functions of practical interest
are still integrable. On the other hand, the basic integral theorems can be
obtained more quickly. We also give a characterization of the integrable
functions and their primitives.


title:
Origin of the Structure of the Kuiper Belt during a Dynamical
  Instability in the Orbits of Uranus and Neptune

abstract:
  We explore the origin and orbital evolution of the Kuiper belt in the
framework of a recent model of the dynamical evolution of the giant planets,
sometimes known as the Nice model. This model is characterized by a short, but
violent, instability phase, during which the planets were on large eccentricity
orbits. One characteristic of this model is that the proto-planetary disk must
have been truncated at roughly 30 to 35 AU so that Neptune would stop migrating
at its currently observed location. As a result, the Kuiper belt would have
initially been empty. In this paper we present a new dynamical mechanism which
can deliver objects from the region interior to ~35 AU to the Kuiper belt
without excessive inclination excitation. Assuming that the last encounter with
Uranus delivered Neptune onto a low-inclination orbit with a semi-major axis of
~27 AU and an eccentricity of ~0.3, and that subsequently Neptune's
eccentricity damped in ~1 My, our simulations reproduce the main observed
properties of the Kuiper belt at an unprecedented level.


title: Spanners of Complete $k$-Partite Geometric Graphs

abstract:
  We address the following problem: Given a complete $k$-partite geometric
graph $K$ whose vertex set is a set of $n$ points in $\mathbb{R}^d$, compute a
spanner of $K$ that has a ``small'' stretch factor and ``few'' edges. We
present two algorithms for this problem. The first algorithm computes a
$(5+\epsilon)$-spanner of $K$ with O(n) edges in $O(n \log n)$ time. The second
algorithm computes a $(3+\epsilon)$-spanner of $K$ with $O(n \log n)$ edges in
$O(n \log n)$ time. The latter result is optimal: We show that for any $2 \leq
k \leq n - \Theta(\sqrt{n \log n})$, spanners with $O(n \log n)$ edges and
stretch factor less than 3 do not exist for all complete $k$-partite geometric
graphs.


title: Photometrically simply behaving mCP stars

abstract:
  We analyzed uvby and Hp light curves of 19 well observed magnetic CP stars
selected from the "On-line database of photometric observations of mCP stars"
of which light curves in all the five colours were similar. We assumed that
among these photometrically simply behaving (PSB) stars could be found such
ones which have a single photometric spot. The insight into such simple
situations would help us to comprehend more complicated cases. Light curves of
the 19 PSB mCP stars proved to be generally nearly symmetric but surprisingly
diverse. The analysis shows that only in the case of HD 110956B, HD 188041, and
perhaps HD 193722 we are able to explain their photometric behaviour by a
simple one-spot model. Consequently, occurrence of more than one photometric
spot on an mCP star is typical.


title: Fragmenting random permutations

abstract:
  Problem 1.5.7 from Pitman's Saint-Flour lecture notes: Does there exist for
each n a fragmentation process (\Pi_{n,k}, 1 \leq k \leq n) taking values in
the space of partitions of {1,2,...,n} such that \Pi_{n,k} is distributed like
the partition generated by cycles of a uniform random permutation of
{1,2,...,n} conditioned to have k cycles? We show that the answer is yes. We
also give a partial extension to general exchangeable Gibbs partitions.


title:
Kinetics of the Phase Separation Transition in Cold-Atom Boson-Fermion
  Mixtures

abstract:
  We study the kinetics of the first order phase separation transition in
boson-fermion cold-atom mixtures. At sufficiently low temperatures such a
transition is driven by quantum fluctuations responsible for the formation of
critical nuclei of a stable phase. Based on a microscopic description of
interacting boson-fermion mixtures we derive an effective action for the
critical droplet and obtain an asymptotic expression for the nucleation rate in
the vicinity of the phase transition and near the spinodal instability of the
mixed phase. We also discuss effects of dissipation which play a dominant role
close to the transition point, and identify the regimes where quantum
nucleation can be experimentally observed in cold-atom systems.


title:
Quivers, Geometric Invariant Theory, and Moduli of Linear Dynamical
  Systems

abstract:
  We use geometric invariant theory and the language of quivers to study
compactifications of moduli spaces of linear dynamical systems. A general
approach to this problem is presented and applied to two well known cases: We
show how both Lomadze's and Helmke's compactification arises naturally as a
geometric invariant theory quotient. Both moduli spaces are proven to be smooth
projective manifolds. Furthermore, a description of Lomadze's compactification
as a Quot scheme is given, whereas Helmke's compactification is shown to be an
algebraic Grassmann bundle over a Quot scheme. This gives an algebro-geometric
description of both compactifications. As an application, we determine the
cohomology ring of Helmke's compactification and prove that the two
compactifications are not isomorphic when the number of outputs is positive.


title:
Signature of the Overhauser field on the coherent spin dynamics of
  donor-bound electron in a single CdTe quantum well

abstract:
  We have studied the coherent spin dynamics in an oblique magnetic field of
electrons localized on donors and placed in the middle of a single CdTe quantum
well, by using a time-resolved optical technique: the photo-induced Faraday
rotation. We showed that this dynamics is affected by a weak Overhauser field
created via the hyperfine interaction of optically spin-polarized donor-bound
electrons with the surrounding nuclear isotopes carrying non-zero spins. We
have measured this nuclear field, which is on the order of a few mT and can
reach a maximum experimental value of 9.4 mT. This value represents 13 % of the
maximal nuclear polarization, and corresponds also to 13 % of maximal
electronic polarization.


title: Differential Equations in Metric Spaces with Applications

abstract:
  This paper proves the local well posedness of differential equations in
metric spaces under assumptions that allow to comprise several different
applications. We consider below a system of balance laws with a dissipative non
local source, the Hille-Yosida Theorem, a generalization of a recent result on
nonlinear operator splitting, an extension of Trotter formula for linear
semigroups and the heat equation.


title:
Exposing metal and silicate charges to electrical discharges: Did
  chondrules form by nebular lightning?

abstract:
  In order to investigate the hypothesis that dust aggregates were transformed
to meteoritic chondrules by nebular lightning, we exposed silicatic and
metallic dust samples to electric discharges with energies of 120 to 500 J in
air at pressures between 10 and 10^5 Pa. The target charges consisted of
powders of micrometer-sized particles and had dimensions of mm. The dust
samples generally fragmented leaving the major fraction thermally unprocessed.
A minor part formed sintered aggregates of 50 to 500 micrometer. In a few
experiments melt spherules having sizes smaller than 180 micrometer in diameter
(and, generally, interior voids) were formed; the highest spherule fraction was
obtained with metallic Ni. Our experiments indicate that chondrule formation by
electric current or by particle bombardment inside a discharge channel is
unlikely.


title: Investigating electron interacting dark matter

abstract:
  Some extensions of the Standard Model provide Dark Matter candidate particles
which can have a dominant coupling with the lepton sector of the ordinary
matter. Thus, such Dark Matter candidate particles ($\chi^{0}$) can be directly
detected only through their interaction with electrons in the detectors of a
suitable experiment, while they are lost by experiments based on the rejection
of the electromagnetic component of the experimental counting rate. These
candidates can also offer a possible source of the 511 keV photons observed
from the galactic bulge. In this paper this scenario is investigated. Some
theoretical arguments are developed and related phenomenological aspects are
discussed. Allowed intervals and regions for the characteristic
phenomenological parameters of the considered model and of the possible
mediator of the interaction are also derived considering the DAMA/NaI data.


title: Fragmentation of the fireball and how to observe it

abstract:
  We argue that fragmentation at hadronisation is likely scenario in
ultrarelativistic nuclear collisions. In case of crossover phase transition it
is driven by a singularity of the bulk viscosity. We claim that such a scenario
can explain the ``HBT puzzle'' and can be identified by non-statistical
differences between event-wise rapidity distributions and by proton-proton
rapidity correlations.


title: Magnetostructure of MnAs on GaAs revisited

abstract:
  The ferromagnetic to nonferromagnetic (α-β) phase transition in
epitaxial MnAs layers on GaAs(100) is studied by x-ray magnetic circular
dichroism and x-ray magnetic linear dichroism photoemission electron microscopy
in order to elucidate the nature of the controversial nonferromagnetic state of
β-MnAs. In the coexistence region of the two phases the β phase shows
a clear XMLD signal characteristic of antiferromagnetism. The nature and the
possible causes of the elusiveness of this magnetic state are discussed.


title: Le Chatelier-Braun principle in cosmological physics

abstract:
  Assuming that dark energy may be treated as a fluid with a well defined
temperature, close to equilibrium, we argue that if nowadays there is a
transfer of energy between dark energy and dark matter, it must be such that
the latter gains energy from the former and not the other way around.


title:
Dirac-Coulomb scattering with plane wave energy eigenspinors on de
  Sitter expanding universe

abstract:
  The lowest order contribution of the amplitude of Dirac-Coulomb scattering in
de Sitter spacetime is calculated assuming that the initial and final states of
the Dirac field are described by exact solutions of the free Dirac equation on
de Sitter spacetime with a given energy and helicity. We find that the total
energy is conserved in the scattering process.


title: GRB 060218 and the binaries as progenitors of GRB-SN systems

abstract:
  (shortened) We study the Gamma-Ray Burst (GRB) 060218: a particularly close
source at z=0.033 with an extremely long duration, namely T_{90} ~ 2000 s,
related to SN 2006aj. [...] I present the fitting time consuming procedure. In
order to show its sensitivity I also present two examples of fits with the same
value of B and different value of E_{e^\pm}^{tot}. We fit the X- and \gamma-ray
observations by Swift of GRB 060218 in the 0.1-150 keV energy band during the
entire time of observations from 0 all the way to 10^6 s within a unified
theoretical model. The free parameters of our theory are only three, namely the
total energy E_{e\pm}^{tot} of the e^\pm plasma, its baryon loading B \equiv
M_Bc^2/E_{e\pm}^{tot}, as well as the CircumBurst Medium (CBM) distribution. We
justify the extremely long duration of this GRB by a total energy
E_{e\pm}^{tot} = 2.32\times 10^{50} erg, a very high value of the baryon
loading B=1.0\times 10^{-2} and the effective CircumBurst Medium (CBM) density
which shows a radial dependence n_{cbm} \propto r^{-\alpha} with 1.0 \leq
\alpha \leq 1.7 and monotonically decreases from 1 to $10^{-6}$
particles/cm$^3$. We recall that this value of the $B$ parameter is the highest
among the sources we have analyzed and it is very close to its absolute upper
limit expected. [...] We also think that the smallest possible black hole,
formed by the gravitational collapse of a neutron star in a binary system, is
consistent with the especially low energetics of the class of GRBs associated
with SNe Ib/c.


title: Recent results on unintegrated parton distributions

abstract:
  We summarize recent results on i) the use of u-pdf's in the Monte-Carlo
simulation of hadronic final states at high-energy colliders, and ii) attempts
to characterize u-pdf's with precision in terms of nonlocal operator matrix
elements.


title:
Commensurability and QI classification of free products of finitely
  generated abelian groups

abstract:
  Suppose a group $G$ is quasi-isometric to a free product of a finite set $S$
of finitely generated abelian groups; let $S'$ denote the set of ranks of the
free abelian parts of the groups in $S$. Then $G$ is commensurable with the
free product of $\Z$ with a $\Z^n$ for each $n$ occurring in $S'$.


title: Resolving the instability of the Savvidy vacuum by dynamical gluon mass

abstract:
  In this paper we apply the formalism of local composite operators as
developed by Verschelde et al. in combination with a constant chromomagnetic
field as considered in the seventies by Savvidy and others. We find that a
nonzero <A_\mu^2> minimizes the vacuum energy, as in the case with no
chromomagnetic field, and that the chromomagnetic field itself is near-to zero.
The Nielsen-Olesen instability, caused by the imaginary part in the action,
also vanishes. We further investigate the effect of an external chromomagnetic
field on the value of <A_\mu^2>, finding that this condensate is destroyed by
sufficiently strong fields. The inverse scenario, where <A_\mu^2> is considered
as external, results in analogous findings: when this condensate is
sufficiently large, the induced chromomagnetic field is lowered to a
perturbative value slightly below the applied <A_\mu^2>.


title: Eternal Inflation, past and future

abstract:
  Cosmological inflation, if it occurred, radically alters the picture of the
`big bang', which would merely point to reheating at the end of inflation.
Moreover, this reheating may be only local, so that inflation continues
elsewhere and forever, continually spawning big-bang-like regions. This chapter
reviews this idea of `eternal inflation', then focuses on what this may mean
for the ultimate beginning of the universe. In particular, I will argue that
given eternal inflation, the universe may be free of a cosmological initial
singularity, might be eternal (and eternally inflating) to the past, and might
obey an interesting sort of cosmological time-symmetry.


title: A dispersive approach to pion photo- and electroproduction

abstract:
  The relativistic amplitudes of pion photo- and electroproduction are
calculated by dispersion relations at constant t. Several sum rules and
low-energy theorems for the threshold amplitudes are investigated within this
technique. The continuation of the amplitudes to sub-threshold kinematics is
shown to provide a unique framework to derive the low-energy constants of
chiral perturbation theory by global properties of the excitation spectrum.


title: A Modern Fareytail

abstract:
  We revisit the "fareytail expansions" of elliptic genera which have been used
in discussions of the AdS_3/CFT_2 correspondence and the OSV conjecture. We
show how to write such expansions without the use of the problematic "fareytail
transform." In particular, we show how to write a general vector-valued modular
form of non-positive weight as a convergent sum over cosets of SL(2,Z). This
sum suggests a new regularization of the gravity path integral in AdS_3,
resolves the puzzles associated with the "fareytail transform," and leads to
several new insights. We discuss constraints on the polar coefficients of
negative weight modular forms arising from modular invariance, showing how
these are related to Fourier coefficients of positive weight cusp forms. In
addition, we discuss the appearance of holomorphic anomalies in the context of
the fareytail.


title:
Large deviations for local time fractional Brownian motion and
  applications

abstract:
  Let $W^H=\{W^H(t), t \in \rr\}$ be a fractional Brownian motion of Hurst
index $H \in (0, 1)$ with values in $\rr$, and let $L = \{L_t, t \ge 0\}$ be
the local time process at zero of a strictly stable L\'evy process $X=\{X_t, t
\ge 0\}$ of index $1<\alpha\leq 2$ independent of $W^H$. The $\a$-stable local
time fractional Brownian motion $Z^H=\{Z^H(t), t \ge 0\}$ is defined by $Z^H(t)
= W^H(L_t)$. The process $Z^H$ is self-similar with self-similarity index $H(1
- \frac 1 \alpha)$ and is related to the scaling limit of a continuous time
random walk with heavy-tailed waiting times between jumps
(\cite{coupleCTRW,limitCTRW}). However, $Z^H$ does not have stationary
increments and is non-Gaussian.
  In this paper we establish large deviation results for the process $Z^H$. As
applications we derive upper bounds for the uniform modulus of continuity and
the laws of the iterated logarithm for $Z^H$.


title:
Voltage rectification effects in mesoscopic superconducting triangles:
  experiment and modelling

abstract:
  The interaction of externally applied currents with persistent currents
induced by magnetic field in a mesoscopic triangle is investigated. As a
consequence of the superposition of these currents, clear voltage rectification
effects are observed. We demonstrate that the amplitude of the rectified signal
strongly depends on the configurations of the current leads with the lowest
signal obtained when the contacts are aligned along a median of the triangle.
When the contacts are aligned off-centered compared to the geometrical center,
the voltage response shows oscillations as a function of the applied field,
whose sign can be controlled by shifting the contacts. These results are in
full agreement with theoretical predictions for an analogous system consisting
of a closed loop with a finite number of identical Josephson junctions.


title:
Inverse problems for regular variation of linear filters, a cancellation
  property for $\sigma$-finite measures and identification of stable laws

abstract:
  In this paper, we consider certain $\sigma$-finite measures which can be
interpreted as the output of a linear filter. We assume that these measures
have regularly varying tails and study whether the input to the linear filter
must have regularly varying tails as well. This turns out to be related to the
presence of a particular cancellation property in $\sigma$-finite measures,
which in turn, is related to the uniqueness of the solution of certain
functional equations. The techniques we develop are applied to weighted sums of
i.i.d. random variables, to products of independent random variables, and to
stochastic integrals with respect to L\'evy motions.


title: Kerr Geometry as Space-Time Structure of the Dirac Electron

abstract:
  The combined Dirac-Kerr model of electron is suggested, in which electron has
extended space-time structure of Kerr geometry, and the Dirac equation plays
the role of a master equation controlling polarization of the Kerr congruence.
The source contains a spinning disk bounded by a closed singular string of
Compton size. It is conjectured that this Compton structure may be observed for
polarized electrons under a very soft coherent scattering.


title: The infrared JHK light curves of RR Lyr

abstract:
  We present infrared JHK time series photometry of the variable star RR Lyr,
that allow us to construct the first complete and accurate infrared light
curves for this star. The derived mean magnitudes are <J>=6.74 +/- 0.02,
<H>=6.60 +/- 0.03 and <K>=6.50 +/- 0.02. The <K> magnitude is used to estimate
the reddening, the mass, the mean luminosity and temperature of this variable
star. The use of these RR Lyr data provide a more accurate absolute calibration
of the P-L_K-[Fe/H] relation, and a distance modulus (m-M)_0=18.48 +/- 0.11 to
the globular cluster Reticulum in the LMC.


title: Kinematics of a hot massive accretion disk candidate

abstract:
  Characterizing rotation, infall and accretion disks around high-mass
protostars is an important topic in massive star formation research. With the
Australia Telescope Compact Array and the Very Large Array we studied a massive
disk candidate at high angular resolution in ammonia (NH3(4,4) & (5,5)) tracing
the warm disk but not the envelope. The observations resolved at ~0.4''
resolution (corresponding to ~1400AU) a velocity gradient indicative of
rotation perpendicular to the molecular outflow. Assuming a Keplerian accretion
disk, the estimated protostar-disk mass would be high, similar to the
protostellar mass. Furthermore, the position-velocity diagram exhibits
additional deviation from a Keplerian rotation profile which may be caused by
infalling gas and/or a self-gravitating disk. Moreover, a large fraction of the
rotating gas is at temperatures >100K, markedly different to typical low-mass
accretion disks. In addition, we resolve a central double-lobe cm continuum
structure perpendicular to the rotation. We identify this with an ionized,
optically thick jet.


title: Stochastic FitzHugh-Nagumo equations on networks with impulsive noise

abstract:
  We consider a system of nonlinear partial differential equations with
stochastic dynamical boundary conditions that arises in models of
neurophysiology for the diffusion of electrical potentials through a finite
network of neurons. Motivated by the discussion in the biological literature,
we impose a general diffusion equation on each edge through a generalized
version of the FitzHugh-Nagumo model, while the noise acting on the boundary is
described by a generalized stochastic Kirchhoff law on the nodes. In the
abstract framework of matrix operators theory, we rewrite this stochastic
boundary value problem as a stochastic evolution equation in infinite
dimensions with a power-type nonlinearity, driven by an additive L\'evy noise.
We prove global well-posedness in the mild sense for such stochastic partial
differential equation by monotonicity methods.


title: Gesture analysis for physics education researchers

abstract:
  Systematic observations of student gestures can not only fill in gaps in
students' verbal expressions, but can also offer valuable information about
student ideas, including their source, their novelty to the speaker, and their
construction in real time. This paper provides a review of the research in
gesture analysis that is most relevant to physics education researchers and
illustrates gesture analysis for the purpose of better understanding student
thinking about physics.


title:
Evidence of enhanced star formation efficiency in luminous and
  ultraluminous infrared galaxies

abstract:
  We present new observations made with the IRAM 30m telescope of the J=1-0 and
3-2 lines of HCN and HCO^+ used to probe the dense molecular gas content in a
sample of 17 local luminous and ultraluminous infrared galaxies (LIRGs and
ULIRGs). These observations have allowed us to derive an updated version of the
power law describing the correlation between the FIR luminosity (L_FIR) and the
HCN(1-0) luminosity (L'_HCN(1-0)) of local and high-redshift galaxies. We
present the first clear observational evidence that the star formation
efficiency of the dense gas (SFE_dense), measured as the L_FIR/L'_HCN(1-0)
ratio, is significantly higher in LIRGs and ULIRGs than in normal galaxies, a
result that has also been found recently in high-redshift galaxies. This may
imply a statistically significant turn upward in the Kennicutt-Schmidt law
derived for the dense gas at L_FIR >= 10^11 L_sun. We have used a one-phase
Large Velocity Gradient (LVG) radiative transfer code to fit the three
independent line ratios derived from our observations. The results of this
analysis indicate that the [HCN]/[HCO^+] abundance ratios could be up to one
order of magnitude higher than normal in a significant number of LIRGs and
ULIRGs of our sample. An overabundance of HCN at high L_FIR implies that the
reported trend in the L_FIR/L'_HCN ratio as a function of L_FIR would be
underestimating a potentially more dramatic change of the SFE_dense. Results
obtained with two-phase LVG models corroborate that the L'_HCN(1-0)-to-M_dense
conversion factor must be lowered at high L_FIR. We discuss the implications of
these findings for the use of HCN as a tracer of the dense molecular gas in
local and high-redshift luminous infrared galaxies.


title: Enhanced delay to Bifurcation

abstract:
  This article provides an example of fast-slow system such that most orbits
remain as close as possible to the unstable manifold of the fast dynamics for
an arbitrarily long time.


title: Cardinal sequences of LCS spaces under GCH

abstract:
  We give full characterization of the sequences of regular cardinals that may
arise as cardinal sequences of locally compact scattered spaces under GCH.
  The proofs are based on constructions of universal locally compact scattered
spaces.


title:
Non group-theoretical semisimple Hopf algebras from group actions on
  fusion categories

abstract:
  Given an action of a finite group G on a fusion category C we give a
criterion for the category of G-equivariant objects in C to be
group-theoretical, i.e., to be categorically Morita equivalent to a category of
group-graded vector spaces. We use this criterion to answer affirmatively the
question about existence of non group-theoretical semisimple Hopf algebras
asked by P. Etingof, V. Ostrik, and the author in math/0203060. Namely, we show
that certain Z/2Z-equivariantizations of fusion categories constructed by D.
Tambara and S. Yamagami are equivalent to representation categories of non
group-theoretical semisimple Hopf algebras. We describe these Hopf algebras as
extensions and show that they are upper and lower semisolvable.


title:
Harmonic emission from cluster nanoplasmas subject to intense short
  laser pulses

abstract:
  Harmonic emission from cluster nanoplasmas subject to short intense infrared
laser pulses is studied. In a previous publication [M. Kundu et al., Phys. Rev.
A 76, 033201 (2007)] we reported particle-in-cell simulation results showing
resonant enhancements of low-order harmonics when the Mie plasma frequency of
the ionizing and expanding cluster resonates with the respective harmonic
frequency. Simultaneously we found that high-order harmonics were barely
present in the spectrum, even at high intensities. The current paper is focused
on the analytical modeling of the process. We show that dynamical stochasticity
owing to nonlinear resonance inhibits the emission of high order harmonics.


title:
First excitations in two- and three-dimensional random-field Ising
  systems

abstract:
  We present results on the first excited states for the random-field Ising
model. These are based on an exact algorithm, with which we study the
excitation energies and the excitation sizes for two- and three-dimensional
random-field Ising systems with a Gaussian distribution of the random fields.
Our algorithm is based on an approach of Frontera and Vives which, in some
cases, does not yield the true first excited states. Using the corrected
algorithm, we find that the order-disorder phase transition for three
dimensions is visible via crossings of the excitations-energy curves for
different system sizes, while in two-dimensions these crossings converge to
zero disorder. Furthermore, we obtain in three dimensions a fractal dimension
of the excitations cluster of d_s=2.42(2). We also provide analytical droplet
arguments to understand the behavior of the excitation energies for small and
large disorder as well as close to the critical point.


title:
SZ and CMB reconstruction using Generalized Morphological Component
  Analysis

abstract:
  In the last decade, the study of cosmic microwave background (CMB) data has
become one of the most powerful tools to study and understand the Universe.
More precisely, measuring the CMB power spectrum leads to the estimation of
most cosmological parameters. Nevertheless, accessing such precious physical
information requires extracting several different astrophysical components from
the data. Recovering those astrophysical sources (CMB, Sunyaev-Zel'dovich
clusters, galactic dust) thus amounts to a component separation problem which
has already led to an intense activity in the field of CMB studies. In this
paper, we introduce a new sparsity-based component separation method coined
Generalized Morphological Component Analysis (GMCA). The GMCA approach is
formulated in a Bayesian maximum a posteriori (MAP) framework. Numerical
results show that this new source recovery technique performs well compared to
state-of-the-art component separation methods already applied to CMB data.