title:
Structural and Nucleosynthetic Evolution of Metal-poor and Metal-free
  Low and Intermediate Mass Stars

abstract:
  We report on an investigation into stellar evolution and nucleosynthesis in
the low and extremely low metallicity regime, including models of stars with a
pure Big Bang composition (i.e. Z=0). The metallicity range of the extremely
metal poor (EMP) models we have calculated is -6.5 < [Fe/H] < -3.0, whilst our
models are in the mass range 0.85 < M < 3.0 Msun. Many of the EMP and Z=0
models experience violent evolutionary episodes not seen at higher
metallicities. We refer to these events as `Dual Flashes' since they are
characterised by peaks in the hydrogen and helium burning luminosities
occurring at roughly the same time. Some of the material processed by these
events is later dredged up by the convective envelope, causing signifcant
surface pollution. These events have been reported by previous studies, so our
results reaffirm their occurrence -- at least in 1D stellar models. The novelty
of this study is that we have calculated the entire evolution of the Z=0 and
EMP models, from the ZAMS to the end of the TPAGB, including detailed
nucleosynthesis. We have also calculated the nucleosynthetic yields, which will
soon be available in electronic format. Although subject to many uncertainties
these are, as far as we are aware, the only yields available in this mass and
metallicity range. In this paper we briefy describe some of the results in the
context of abundance observations of EMP halo stars. This work formed part of
SWC's PhD thesis (completed in March 2007) and a series of subsequent papers
will describe the results of the study in more detail.


title: Gamma-Ray Burst high energy emission from Internal Shocks

abstract:
  In this paper we study synchrotron and synchrotron self Compton (SSC)
emission from internal shocks (IS) during the prompt and X-ray flare phases of
Gamma-Ray Bursts (GRBs). The aim is to test the IS model for the flare emission
and for whether GRBs can be GeV sources. We determine the parameters for which
the IS model can account for the observed prompt and X-ray flares emission, and
study the detectability of the high energy SSC emission by the AGILE and GLAST
satellites. We find that the detectability of the SSC emission during the
prompt phase of GRBs improves for higher values of the fireball Lorentz factor
and of the temporal variability. If IS is the mechanism responsible of the
flare emission, and the Lorentz factor of the shells producing the flare is of
the order of 100, the flare light curves are expected to present some
substructures with temporal variability of 10-100 ms which are much smaller
than the average duration of flares, and similar to those observed during the
prompt phase of GRBs. If one assumes lower Lorentz factors, such as 10-25, then
a larger temporal variaibility of 40 s can also account for the observed flare
properties. However in this case we predict that X-ray flares do not have a
counterpart at very high energies (MeV-GeV). An investigation on the
substructures of the X-ray flares light curves, and simultaneous X-ray and high
energy observations, will allow us to corroborate the hypothesis that late IS
are responsible of the X-ray flares.


title:
Diffusion-controlled death of $A$-particle and $B$-particle islands at
  propagation of the sharp annihilation front $A + B \to 0$

abstract:
  We consider the problem of diffusion-controlled evolution of the system
$A$-particle island - $B$-particle island at propagation of the sharp
annihilation front $A+B\to 0$. We show that this general problem, which
includes as particular cases the sea-sea and the island-sea problems,
demonstrates rich dynamical behavior from self-accelerating collapse of one of
the islands to synchronous exponential relaxation of the both islands. We find
a universal asymptotic regime of the sharp front propagation and reveal limits
of its applicability for the cases of mean-field and fluctuation fronts.


title: Gamma-Ray Emission from PWNe Interacting with Molecular Clouds

abstract:
  We consider a situation in which a pulsar (and its nebula) is formed inside
or close to a high density regions of a molecular cloud. We apply a recent
model for the gamma radiation of pulsar wind nebulae (PWN), which includes not
only radiation processes due to injected leptons but also processes due to
injection of relativistic hadrons, in order to calculate the expected gamma-ray
emission from such interacting PWNe. The example calculations have been
performed for two objects of this type from which directions TeV gamma-ray
sources have recently been observed (IC443 and W41). We show that the gamma-ray
emission below a few TeV can be produced by leptons accelerated in the past in
the vicinity of the pulsars. gamma-rays with energies above ~10 TeV can be
produced by hadrons interacting with the matter inside the supernova remnant
and surrounding dense clouds. In contrary to the low energy TeV emission, this
high energy TeV emission should be correlated with the location of dense clouds
able to capture hadrons due to their strong magnetic fields.


title: Einstein's Lost Battles and Neglected Achievements

abstract:
  We analyze some of Einstein's failures to accomplish tasks which he posed to
himself, notably deterministic interpretation of Quantum mechanics and
formulation of the Unified theory of physical interactions, putting them into
broader ontological and epistemological context. We highlight, on the other
hand, a number of his contributions that have been unjustly neglected by the
physical community, like the semiclassical quantization principle and the
concept of antiparticle. Finally, we mention briefly three issues, which are
related to Einstein, but are subject to controversy.


title: Measurement of Heavy Quark cross-sections at CDF

abstract:
  The measurement of heavy quark cross-sections provides important tests of the
QCD theory. This paper reviews recent measurements of single b-quark and
correlated b-quark cross-sections at CDF. Two new measurements of the single
b-quark production at CDF agree with the first result from CDF Run II. This
clarifies the experimental situation and confirms the recent agreement of
theoretical prediction with data. A new measurement of the correlated
$b\bar{b}$ cross-section with dimuon events at CDF is presented. It agrees with
theory and it does not confirm the anomalously large $b\bar{b}$ cross-section
seen in Run I by CDF and D${\not {\rm O}}$ in dimuon events.


title: Pulsating B and Be stars in the Small Magellanic Cloud

abstract:
  Context: Stellar pulsations in main-sequence B-type stars are driven by the
kappa-mechanism due to the Fe-group opacity bump. The current models do not
predict the presence of instability strips in the B spectral domain at very low
metallicities. As the metallicity of the SMC is lower than Z=0.005, it
constitutes a very suitable object to test these predictions.
  Aims: The main objective is to investigate the existence of B-type pulsators
at low metallicities, searching for short-term periodic variability in
absorption-line B and Be stars in the SMC. The analysis has been performed in a
sample of 313 B and Be stars with fundamental astrophysical parameters
accurately determined from high-resolution spectroscopy.
  Methods: Photometric light curves of the MACHO project have been analyzed
using standard Fourier techniques and linear and non-linear least squares
fitting methods. The position of the pulsating stars in the HR diagram has been
used to ascertain their nature and to map the instability regions in the SMC.
  Results: We have detected 9 absorption-line B stars showing short-period
variability, two among them being multiperiodic. One star is most likely a beta
Cephei variable and the remaining 8 are SPB stars. The SPB instability strip in
the SMC is shifted towards higher temperatures than the Galaxy. In the Be star
sample, 32 stars are short-period variables, 20 among them multiperiodic. 4.9%
of B stars and 25.3% of Be stars are pulsating stars.
  Conclusions: beta Cephei and SPB stars do exist at the SMC metallicity. The
fractions of SPB stars and pulsating Be stars in the SMC are lower than in the
Galaxy. The fraction of pulsating Be stars in the SMC is much higher than the
fraction of pulsating absorption-line B stars, as in the Galaxy.


title:
Light quark masses and pseudoscalar decay constants from Nf=2 Lattice
  QCD with twisted mass fermions

abstract:
  We present the results of a lattice QCD calculation of the average up-down
and strange quark masses and of the light meson pseudoscalar decay constants
with Nf=2 dynamical fermions. The simulation is carried out at a single value
of the lattice spacing with the twisted mass fermionic action at maximal twist,
which guarantees automatic O(a)-improvement of the physical quantities. Quark
masses are renormalized by implementing the non-perturbative RI-MOM
renormalization procedure. Our results for the light quark masses are
m_ud^{msbar}(2 GeV)= 3.85 +- 0.12 +- 0.40 MeV, m_s^{msbar}(2 GeV) = 105 +- 3 +-
9 MeV and m_s/m_ud = 27.3 +- 0.3 +- 1.2. We also obtain fK = 161.7 +- 1.2 +-
3.1 MeV and the ratio fK/fpi=1.227 +- 0.009 +- 0.024. From this ratio, by using
the experimental determination of Gamma(K-> mu nu (gamma))/Gamma(pi -> mu nu
(gamma)) and the average value of |Vud| from nuclear beta decays, we obtain
|Vus|=0.2192(5)(45), in agreement with the determination from Kl3 decays and
the unitarity constraint.


title:
Density profiles in the raise and peel model with and without a wall.
  Physics and combinatorics

abstract:
  We consider the raise and peel model of a one-dimensional fluctuating
interface in the presence of an attractive wall. The model can also describe a
pair annihilation process in a disordered unquenched media with a source at one
end of the system. For the stationary states, several density profiles are
studied using Monte Carlo simulations. We point out a deep connection between
some profiles seen in the presence of the wall and in its absence. Our results
are discussed in the context of conformal invariance ($c = 0$ theory). We
discover some unexpected values for the critical exponents, which were obtained
using combinatorial methods.
  We have solved known (Pascal's hexagon) and new (split-hexagon) bilinear
recurrence relations. The solutions of these equations are interesting on their
own since they give information on certain classes of alternating sign
matrices.


title: Confinement of Cosmic Rays in Dark Matter clumps

abstract:
  Some part of the relic Dark Matter is distributed in small-scale clumps which
survived structure formation in inflation cosmological scenario. The
annihilation of DM inside these clumps is a strong source of stable charged
particles which can have a substantial density near the clump core. The
streaming of the annihilation products from the clump can enhance
irregularities in the galactic magnetic field. This can produce small scale
variations in diffusion coefficient affecting propagation of Cosmic Rays.


title:
Sub-Kelvin Cooling of a Macroscopic Oscillator and femto-Newton Force
  Measurement

abstract:
  Measuring very small forces, particularly those of a gravitational nature,
has always been of great interest, as fundamental tests of our understanding of
the physical laws. Ultra-long period mechanical oscillators, typically used in
such measurements, will have kT/2 of thermal energy associated with each degree
of freedom, owing to the equal-partition of energy. Moreover, additional
seismic fluctuations in the low frequency band can raise this equivalent
temperature significantly to 10^5 K. Recently, various methods using
opto-mechanical forces have been reported to decrease this thermal energy for
MHz, micro-cantilever oscillators, effectively cooling them. Here we show the
direct, dynamical cooling of a gram-size, macroscopic oscillator to 300 mK in
equivalent temperature - noise reduction by a factor of 10^6. By precisely
measuring the torsional oscillator's position, we dynamically provide an
external 'viscous' damping force. Such an added, dissipative force is
essentially free of noise, resulting in rapid cooling of the oscillator.
Additionally, we observe the time-dependent cooling process, at various cooling
force parameters. This parameter dependence agrees well with a simple physical
model which we provide. We further show that the device is sensitive to forces
as small as <100 fN - a force only a few percent of that typically exerted by a
single biological molecule or that observed in a typical gravity experiment. We
also demonstrate the dynamic control of the oscillator's natural frequency,
over a span of nearly two decades. The method may find important applications
in precision measurements of very weak forces.


title: On the Nature of Precursors in the Radio Pulsar Profiles

abstract:
  In the average profiles of several radio pulsars, the main pulse is
accompanied by the preceding component. This so called precursor is known for
its distinctive polarization, spectral, and fluctuation properties. Recent
single-pulse observations hint that the sporadic activity at the extreme
leading edge of the pulse may be prevalent in pulsars. We for the first time
propose a physical mechanism of this phenomenon. It is based on the induced
scattering of the main pulse radiation into the background. We show that the
scattered component is directed approximately along the ambient magnetic field
and, because of rotational aberration in the scattering region, appears in the
pulse profile as a precursor to the main pulse. Our model naturally explains
high linear polarization of the precursor emission, its spectral and
fluctuation peculiarities as well as suggests a specific connection between the
precursor and the main pulse at widely spaced frequencies. This is believed to
stimulate multifrequency single-pulse studies of intensity modulation in
different pulsars.


title: Classification problems of toric manifolds via topology

abstract:
  We propose some problems on the classification of toric manifolds from the
viewpoint of topology and survey related results.


title:
Influence of mechanical properties on mixing and segregation of granular
  material

abstract:
  Processes of mixing and segregation in a packed bed of granular material
stirred by a periodically moving rectangular bar are simulated by the discrete
element method (DEM). Influence of mechanical properties of the particle
material (dynamic friction coefficient, density, elastic modulus) on the
segregation intensity is researched. Dynamic friction coefficient was found to
have the most noticeable influence to the segregation intensity.


title: Detecting a Lorentz-Violating Field in Cosmology

abstract:
  We consider cosmology in the Einstein-aether theory (the generally covariant
theory of gravitation coupled to a dynamical timelike Lorentz-violating vector
field) with a linear aether-Lagrangian. The 3+1 spacetime splitting approach is
used to derive covariant and gauge invariant perturbation equations which are
valid for a general class of Lagrangians. Restricting attention to the
parameter space of these theories which is consistent with local gravity
experiments, we show that there are tracking behaviors for the aether field,
both in the background cosmology and at linear perturbation level. The
primordial power-spectrum of scalar perturbations in this model is shown to be
the same that predicted by standard general relativity. However, the
power-spectrum of tensor perturbation is different from that in general
relativity, but has a smaller amplitude and so cannot be detected at present.
We also study the implications for late-time cosmology and find that the
evolution of photon and neutrino anisotropic stresses can source the aether
field perturbation during the radiation and matter dominated epochs, and as a
result the CMB and matter power spectra are modified. However these effects are
degenerate with respect to other cosmological parameters, such as neutrino
masses and the bias parameter in the observed galaxy spectrum.


title: Dynamical Chirally Improved Quarks: First Results for Hadron Masses

abstract:
  We present first results for a study with two mass-degenerate dynamical
Chirally Improved (CI) fermions on lattices of spatial extent 2.4 fm. The CI
Dirac operator obeys the Ginsparg-Wilson condition in good approximation. The
pion mass we use is still large O(470 MeV) for the 16**3*32 lattices with
lattice spacing of 0.15 fm. The hadron masses are obtained with the variational
technique and the results compared with earlier quenched calculations with
similar lattice parameters. We find indications for the isovector, scalar meson
a0(980) near the experimental value, in contradistinction to quenched results
which always produced a mass value compatible with the first excitation
a0(1450).


title:
Chiral effective-field theory in the Delta(1232) region: II. radiative
  pion photoproduction

abstract:
  We present a theoretical study of the radiative pion photoproduction on the
nucleon ($\gamma N \to \pi N \gamma'$) in the $\De$-resonance region, with the
aim to determine the magnetic dipole moment (MDM) of the $\Delta^+(1232)$. The
study is done within the framework of chiral effective-field theory where the
expansion is performed (to next-to-leading order) in the $\delta$
power-counting scheme which is an extension of chiral perturbation theory to
the $\Delta$-resonance energy region. We present the results for the absorptive
part of the $\Delta$ MDM, as well as perform a sensitivity study of the
dependence of $\gamma N \to \pi N \gamma'$ observables on the real part of the
$\Delta$ MDM. We find that an asymmetry for circular polarization of the photon
beam may provide a model-independent way to measure the $\Delta$ MDM.


title:
New constraints on the Mid-IR EBL from the HESS discovery of VHE gamma
  rays from 1ES 0229+200

abstract:
  AIMS: To investigate the very high energy (VHE: >100 GeV) gamma-ray emission
from the high-frequency peaked BL Lac 1ES 0229+200.
  METHODS: Observations of 1ES 0229+200 at energies above 580 GeV were
performed with the High Energy Stereoscopic System (HESS) in 2005 and 2006.
  RESULTS: 1ES 0229+200 is discovered by HESS to be an emitter of VHE photons.
A signal is detected at the 6.6 sigma level in the HESS observations (41.8 h
live time). The integral flux above 580 GeV is (9.4 +- 1.5 {stat} +- 1.9
{syst}) x 10^{-13} cm^{-2} s^{-1}, corresponding to ~1.8% of the flux observed
from the Crab Nebula. The data show no evidence for significant variability on
any time scale. The observed spectrum is characterized by a hard power law
(Gamma = 2.50 +- 0.19 {stat} +- 0.10 {syst}) from 500 GeV to ~15 TeV.
  CONCLUSIONS: The high-energy range and hardness of the observed spectrum,
coupled with the object's relatively large redshift (z=0.1396), enable the
strongest constraints so far on the density of the Extragalactic Background
Light (EBL) in the mid-infrared band. Assuming that the emitted spectrum is not
harder than Gamma_{int} ~ 1.5, the HESS data support an EBL spectrum ~
lambda^{-1} and density close to the lower limit from source counts measured by
Spitzer, confirming the previous indications from the HEGRA data of 1ES
1426+428 (z=0.129). Irrespective of the EBL models used, the intrinsic spectrum
of 1ES 0229+200 is hard, thus locating the high-energy peak of its spectral
energy distribution above a few TeV.


title: Coulomb gauge studies of SU(3) Yang-Mills theory on the lattice

abstract:
  We study the infrared behaviour of lattice SU(3) Yang-Mills theory in Coulomb
gauge in terms of the ghost propagator, the Coulomb potential and the
transversal and the time-time component of the equal-time gluon propagator. In
particular, we focus on the Gribov problem and its impact on the observables.
We observe that the simulated annealing method is advantageous for fixing the
Coulomb gauge in large volumes. We study finite size and discretization
effects. While finite size effects can be controlled by the cone cut, and the
ghost propagator and the Coulomb potential become scaling functions with the
cylinder cut, the equal-time gluon propagator does not show scaling in the
considered range of the inverse coupling constant. The ghost propagator is
infrared enhanced. The Coulomb potential is now extended to considerably lower
momenta and shows a more complicated infrared regime. The Coulomb string
tension satisfies Zwanziger's inequality, but its estimate can be considered
only preliminary because of the systematic Gribov effect that is particularly
strong for the Coulomb potential.


title: Scalar Curvature Estimates by Parallel Alternating Torsion

abstract:
  We generalize Llarull's scalar curvature comparison to Riemannian manifolds
admitting metric connections with parallel and alternating torsion and having a
nonnegative curvature operator on 2-vectors. As a byproduct, we show that Euler
number and signature of such manifolds are determined by their global holonomy
representation. Our result holds in particular for all quotients of compact Lie
groups of equal rank, equipped with a normal homogeneous metric.
  We also correct a mistake in the treatment of odd-dimensional spaces in
arXiv:math/0010199 and arXiv:0705.0500


title: Quadratic equations and monodromy evolving deformations

abstract:
  We give a basic theory on monodromy evolving deformations. proposed by
Chakravarty and Ablowitz in 1996. We show that Halphen's second quadratic
system can be described by monodromy evolving deformations. Our result is a
generalization of the work on the DH-V system by Chakravarty and Ablowitz.


title: m-Mode Regularization Scheme for the Self Force in Kerr Spacetime

abstract:
  We present a new, simple method for calculating the scalar, electromagnetic,
and gravitational self forces acting on particles in orbit around a Kerr black
hole. The standard ``mode-sum regularization'' approach for self-force
calculations relies on a decomposition of the full (retarded) perturbation
field into multipole modes, followed by the application of a certain
mode-by-mode regularization procedure. In recent years several groups have
developed numerical codes for calculating black hole perturbations directly in
2+1 dimensions (i.e., decomposing the azimuthal dependence into $m$-modes, but
refraining from a full multipole decomposition). Here we formulate a practical
scheme for constructing the self force directly from the 2+1-dimensional
$m$-modes. While the standard mode-sum method is serving well in calculations
of the self force in Schwarzschild geometry, the new scheme should allow a more
efficient treatment of the Kerr problem.


title:
All-electric detectors of the polarization state of terahertz laser
  radiation (extended version)

abstract:
  Two types of room temperature detectors of terahertz laser radiation have
been developed which allow in an all-electric manner to determine the plane of
polarization of linearly polarized radiation and the ellipticity of
elliptically polarized radiation, respectively. The operation of the detectors
is based on photogalvanic effects in semiconductor quantum well structures of
low symmetry. The photogalvanic effects have sub-nanosecond time constants at
room temperature making a high time resolution of the polarization detectors
possible.


title: Measurements of the CKM angle gamma at BABAR

abstract:
  We present a short review of the measurements of the CKM angle gamma
performed by the babar experiment. We focus on methods using charged B decays,
which give a direct access to gamma and provide the best constraints so far.


title:
Theoretical study of molecular electronic excitations and optical
  transitions of C60

abstract:
  We report results on ab initio calculations of excited states of the
fullerene molecule by using configuration interaction (CI) approach with singly
excited determinants (SCI). We have used both the experimental geometry and the
one optimized by the density functional method and worked with basis sets at
the cc-pVTZ and aug-cc-pVTZ level. Contrary to the early SCI semiempirical
calculations, we find that two lowest $^1 T_{1u} \leftarrow {}^1 A_g$ electron
optical lines are situated at relatively high energies of ~5.8 eV (214 nm) and
~6.3 eV (197 nm). These two lines originate from two $^1 T_{1u} \leftarrow {}^1
A_g$ transitions: from HOMO to (LUMO+1) ($6h_u \to 3t_{1g}$) and from (HOMO--1)
to LUMO ($10h_g \to 7t_{1u}$). The lowest molecular excitation, which is the $1
^3 T_{2g}$ level, is found at ~2.5 eV. Inclusion of doubly excited determinants
(SDCI) leads only to minor corrections to this picture. We discuss possible
assignment of absorption bands at energies smaller than 5.8 eV (or $\lambda$
larger than 214 nm).


title: The isomorphism conjecture in L-theory: graphs of groups

abstract:
  We study the Fibered Isomorphism Conjecture of Farrell and Jones in L-theory
for groups acting on trees. In several cases we prove the conjecture. This
includes wreath products of abelian groups and free metabelian groups. We also
deduce the conjecture in pseudoisotopy theory for these groups. Finally in B of
Theorem 1.1 we prove the L-theory version of [[7], Theorem 1.2].


title: Gamma Ray Spectrum from Gravitino Dark Matter Decay

abstract:
  Gravitinos are very promising candidates for the cold dark matter of the
Universe. Interestingly, to achieve a sufficiently long gravitino lifetime,
R-parity conservation is not required, thus preventing any dangerous
cosmological influence of the next-to-lightest supersymmetric particle. When
R-parity is violated, gravitinos decay into photons and other particles with a
lifetime much longer than the age of the Universe, producing a diffuse gamma
ray flux with a characteristic spectrum that could be measured in future
experiments, like GLAST or AMS-02. In this letter we compute the energy
spectrum of photons from gravitino decay and discuss its main qualitative
features.


title: Flows of Spin(7)-structures

abstract:
  We consider flows of Spin(7)-structures. We use local coordinates to describe
the torsion tensor of a Spin(7)-structure and derive the evolution equations
for a general flow of a Spin(7)-structure on an 8-manifold M. Specifically, we
compute the evolution of the metric and the torsion tensor. We also give an
explicit description of the decomposition of the space of forms on a manifold
with Spin(7)-structure, and derive an analogue of the second Bianchi identity
in Spin(7)-geometry. This identity yields an explicit formula for the Ricci
tensor and part of the Riemann curvature tensor in terms of the torsion.


title: Worldline Approach to Chiral Fermions

abstract:
  We propose to apply ``worldline numerics'' to a numerical calculation of
quark determinants. The Gross-Neveu model with a U(1) chiral symmetry is
considered as a first test. The worldline approach allows for an analytic
renormalisation, and only finite parts of the determinant require a numerical
calculation. It is shown that the discretisation of the worldlines, which is
central to the numerical treatment, preserves chiral symmetry exactly.
Numerical results for a kink configuration as a scalar background field are
shown and compared with analytical results. The case of finite fermion chemical
potential is also briefly discussed.


title: Ground state fidelity from tensor network representations

abstract:
  For any D-dimensional quantum lattice system, the fidelity between two ground
state many-body wave functions is mapped onto the partition function of a
D-dimensional classical statistical vertex lattice model with the same lattice
geometry. The fidelity per lattice site, analogous to the free energy per site,
is well-defined in the thermodynamic limit and can be used to characterize the
phase diagram of the model. We explain how to compute the fidelity per site in
the context of tensor network algorithms, and demonstrate the approach by
analyzing the two-dimensional quantum Ising model with transverse and parallel
magnetic fields.


title: Some Aspects of Intermediate mass black holes

abstract:
  There is a lot of current astrophysical evidence and interest in intermediate
mass black holes, ranging from a few hundred to several thousand solar masses.
The active galaxy M82 and the globular cluster in M31, for example, are known
to host such objects. Here we discuss several aspects of intermediate mass
black holes such as their expected luminosity, spectral nature of radiation,
associated jets, etc. We also discuss possible scenarios for their formation
including the effects of dynamical friction, gravitational radiation, etc. We
also consider their formation in the early universe and also discuss the
possibility of supermassive black holes forming from mergers of several
intermediate mass black holes and compare the relevant time scales involved
with other scenarios.


title: Upper Limits from HESS Observations of AGN in 2005-2007

abstract:
  Very high energy (VHE; >100 GeV) observations of a sample of selected active
galactic nuclei (AGN) were performed between January 2005 and April 2007 with
the High Energy Stereoscopic System (HESS), an array of imaging
atmospheric-Cherenkov telescopes. Significant detections are reported elsewhere
for many of these objects. Here, integral flux upper limits for twelve
candidate very high energy (VHE; >100 GeV) gamma-ray emitters are presented. In
addition, results from HESS observations of four known VHE-bright AGN are given
although no significant signal is measured. For three of these AGN (1ES
1101-232, 1ES 1218+304, and Mkn 501) simultaneous data were taken with the
Suzaku X-ray satellite.


title:
Braided differential structure on Weyl groups, quadratic algebras and
  elliptic functions

abstract:
  We discuss a class of generalized divided difference operators which give
rise to a representation of Nichols-Woronowicz algebras associated to Weyl
groups. For the root system of type $A,$ we also study the condition for the
deformations of the Fomin-Kirillov quadratic algebra, which is a quadratic lift
of the Nichols-Woronowicz algebra, to admit a representation given by
generalized divided difference operators. The relations satisfied by the
mutually commuting elements called Dunkl elements in the deformed
Fomin-Kirillov algebra are determined. The Dunkl elements correspond to the
truncated elliptic Dunkl operators via the representation given by the
generalized divided difference operators.


title:
Twisted Hopf symmetries of canonical noncommutative spacetimes and the
  no-pure-boost principle

abstract:
  We study the twisted-Hopf-algebra symmetries of observer-independent
canonical spacetime noncommutativity, for which the commutators of the
spacetime coordinates take the form [x^{mu},x^{nu}]=i theta^{mu nu} with
observer-independent (and coordinate-independent) theta^{mu nu}. We find that
it is necessary to introduce nontrivial commutators between transformation
parameters and spacetime coordinates, and that the form of these commutators
implies that all symmetry transformations must include a translation component.
We show that with our noncommutative transformation parameters the Noether
analysis of the symmetries is straightforward, and we compare our
canonical-noncommutativity results with the structure of the conserved charges
and the "no-pure-boost" requirement derived in a previous study of
kappa-Minkowski noncommutativity. We also verify that, while at intermediate
stages of the analysis we do find terms that depend on the ordering convention
adopted in setting up the Weyl map, the final result for the conserved charges
is reassuringly independent of the choice of Weyl map and (the corresponding
choice of) star product.


title:
Multiple stellar populations in Globular Clusters: collection of
  information from the Horizontal Branch

abstract:
  The majority of the inhomogeneities in the chemical composition of Globular
Cluster (GC) stars appear due to primordial enrichment by hot-CNO cycled
material processed in stars belonging to a first stellar generation. Either
massive AGB envelopes subject to hot bottom burning, or the envelopes of
massive fastly rotating stars could be the progenitors. In both cases, the
stars showing chemical anomalies must have also enhanced helium abundance, and
we have proposed that this higher helium could be at the basis of the many
different morphologies of GC horizontal branches (HB) for similar ages and
metallicities. The helium variations have been beautifully confirmed by the
splitting of the main sequence in the clusters omega Cen and NGC 2808, but this
effect can show up only for somewhat extreme helium abundances. Therefore it is
important to go on using the HB morphology to infer the number ratio of the
first to the second generation in as many clusters as possible. We exemplify
how it is possible to infer the presence of a He-rich stellar component in
different clusters thanks to different HB features (gaps, RR Lyr periods and
period distribution, ratio of blue to red stars, blue tails). In many clusters
at least 50% of the stars belong to the second stellar generation, and in some
cases we suspect that the stars might all belong to the second generation. We
shortly examine the problem of the initial mass function required to achieve
the observed number ratios and conclude that: 1) the initial cluster must have
been much more massive than today's cluster, and 2) formation of the second
stellar generation mainly in the central regions of the cluster may help in
obtaining the desired values.


title: Multi-wavelength Observations of PG 1553+113 with HESS

abstract:
  Very high energy (VHE; >100 GeV) gamma-ray observations of PG 1553+113 were
made with the High Energy Stereoscopic System (HESS) in 2005 and 2006. A strong
signal, ~10 standard deviations, is detected by HESS during the 2 years of
observations (24.8 hours live time). The time-averaged energy spectrum,
measured between 225 GeV to ~1.3 TeV, is characterized by a very steep power
law (photon index of Gamma = (4.5 +- 0.3 {stat} +- 0.1 {syst}). The integral
flux above 300 GeV is ~3.4% of the Crab Nebula flux and shows no evidence for
any variations, on any time scale. H+K (1.45-2.45 micron) spectroscopy of PG
1553+113 was performed in March 2006 with SINFONI, an integral field
spectrometer of the ESO Very Large Telescope (VLT) in Chile. The redshift of PG
1553+113 is still unknown, as no absorption or emission lines were found.


title:
Action Principle and Modification of the Faddeev-Popov Factor in Gauge
  Theories

abstract:
  The quantum action (dynamical) principle is exploited to investigate the
nature and origin of the Faddeev-Popov (FP) factor in gauge theories without
recourse to path integrals. Gauge invariant as well as gauge non-invariant
interactions are considered to show that the FP factor needs to be modified in
more general cases and expressions for these modifications are derived. In
particular we show that a gauge invariant theory does not necessarily imply the
familiar FP factor for proper quantization.


title: Relativistic analysis of an earth-satellite time transfer

abstract:
  Analytical treatment of time transfer problem for Earth-Satellite system is
presented. The development was made in a complete relativistic framework. In
accordance with modern clock precision and for low altitude orbits, we neglect
the other bodies and consider only the 1/c^2 Earth potential developed up to
the J_2 term in spherical harmonics.


title: Superconformal spaces and implications for superstrings

abstract:
  We clarify some properties of projective superspace by using a manifestly
superconformal notation. In particular, we analyze the N=2 scalar multiplet in
detail, including its action, and the propagator and its super-Schwinger
parameters. The internal symmetry is taken to be noncompact (after Wick
rotation), allowing boundary conditions that preserve it off shell.
Generalization to N=4 suggests the coset superspace PSU(2,2|4)/OSp(4|4) for the
AdS/CFT superstring.


title:
A photometric study of Be stars located in the seismology fields of
  COROT

abstract:
  Context: In preparation for the COROT mission, an exhaustive photometric
study of Be stars located in the seismology fields of the COROT mission has
been performed. The very precise and long-time-spanned photometric observations
gathered by the COROT satellite will give important clues of the origin of the
Be phenomenon.
  Aims: The aim of this work is to find short-period variable Be stars located
in the seismology fields of COROT and to study and characterise their
pulsational properties.
  Methods: Light curves obtained at the Observatorio de Sierra Nevada together
with data from Hipparcos and ASAS-3 of a total of 84 Be stars have been
analysed in order to search for short-term variations. We have applied standard
Fourier techniques and non-linear least-square fitting to the time series.
  Results: We have found 7 multiperiodic, 21 mono-periodic and 26 non-variable
Be stars. Short-term variability has been detected in 74% of early-type Be
stars and in 31% of mid- to late-type Be stars. We have shown that non-radial
pulsations are most frequent among Be stars than in slow-rotating B stars of
the same spectral range.


title: Motion of Spin 1/2 Massive Particle in a Curved Spacetime

abstract:
  Quasi-classical picture of motion of spin 1/2 massive particle in a curved
spacetime is built on base of simple Lagrangian model. The one is constructed
due to analogy with Lagrangian of massive vector particle. Equations of motion
and spin propagation coincide with Papapetrou equations describing dynamic of
classical spinning particle in a curved spacetime.


title: A Spectacular VHE Gamma-Ray Outburst from PKS 2155-304 in 2006

abstract:
  Since 2002 the VHE (>100 GeV) gamma-ray flux of the high-frequency peaked BL
Lac PKS 2155-304 has been monitored with the High Energy Stereoscopic System
(HESS). An extreme gamma-ray outburst was detected in the early hours of July
28, 2006 (MJD 53944). The average flux above 200 GeV observed during this
outburst is ~7 times the flux observed from the Crab Nebula above the same
threshold. Peak fluxes are measured with one-minute time scale resolution at
more than twice this average value. Variability is seen up to ~600 s in the
Fourier power spectrum, and well-resolved bursts varying on time scales of ~200
seconds are observed. There are no strong indications for spectral variability
within the data. Assuming the emission region has a size comparable to the
Schwarzschild radius of a ~10^9 solar mass black hole, Doppler factors greater
than 100 are required to accommodate the observed variability time scales.


title: Super-Tonks-Girardeau regime in trapped one-dimensional dipolar gases

abstract:
  Possible signatures of a super-Tonks-Girardeau gas in bosonic systems of
trapped quasi-one-dimensional dipoles are discussed at zero temperature. We
provide estimation of the frequency of the lowest compressional mode and
compare it to analytical results derived using harmonic approach in the high
density regime. We construct an exact mapping of the ground-state wave function
of one-dimensional dipolar system of bosons, fermions and Bose-Fermi mixture
and conclude that local properties and energy are the same at zero temperature.
A question of to which extent the dipolar potential can be treated long- or
short- range is discussed.


title: Minisuperspace dynamics in a generalized uncertainty principle framework

abstract:
  The minisuperspace dynamics of the Friedmann-Robertson-Walker (FRW) and of
the Taub Universes in the context of a Generalized Uncertainty Principle is
analyzed in detail. In particular, the motion of the wave packets is
investigated and, in both the models, the classical singularity appear to be
probabilistic suppressed. Moreover, the FRW wave packets approach the Planckian
region in a stationary way and no evidences for a Big-Bounce, as predicted in
Loop Quantum Cosmology, appear. On the other hand, the Taub wave packets
provide the right behavior in predicting an isotropic Universe.


title: Quantum and classical integrable sine-Gordon model with defect

abstract:
  Defects which are predominant in a realistic model, usually spoil its
integrability or solvability. We on the other hand show the exact integrability
of a known sine-Gordon field model with a defect (DSG), at the classical as
well as at the quantum level based on the Yang-Baxter equation. We find the
associated classical and quantum R-matrices and the underlying q-algebraic
structures, analyzing the exact lattice regularized model. We derive
algorithmically all higher conserved quantities $C_n, n=1,2,...$ of this
integrable DSG model, focusing explicitly on the contribution of the defect
point to each $C_n$. The bridging condition across the defect, defined through
the B\"acklund transformation is found to induce creation or annihilation of a
soliton by the defect point or its preservation with a phase shift.

categories: hep-th cond-mat.stat-mech math-ph math.DS math.MP nlin.SI


title: Wavelet transform modulus maxima based fractal correlation analysis

abstract:
  The wavelet transform modulus maxima (WTMM) used in the singularity analysis
of one fractal function is extended to study the fractal correlation of two
multifractal functions. The technique is developed in the framework of joint
partition function analysis (JPFA) proposed by Meneveau et al. [1] and is shown
to be equally effective. In addition, we show that another leading approach
developed for the same purpose, namely, relative multifractal analysis, can be
considered as a special case of JPFA at a particular parameter setting.


title: Asteroseismology and Interferometry

abstract:
  Asteroseismology provides us with a unique opportunity to improve our
understanding of stellar structure and evolution. Recent developments,
including the first systematic studies of solar-like pulsators, have boosted
the impact of this field of research within Astrophysics and have led to a
significant increase in the size of the research community. In the present
paper we start by reviewing the basic observational and theoretical properties
of classical and solar-like pulsators and present results from some of the most
recent and outstanding studies of these stars. We centre our review on those
classes of pulsators for which interferometric studies are expected to provide
a significant input. We discuss current limitations to asteroseismic studies,
including difficulties in mode identification and in the accurate determination
of global parameters of pulsating stars, and, after a brief review of those
aspects of interferometry that are most relevant in this context, anticipate
how interferometric observations may contribute to overcome these limitations.
Moreover, we present results of recent pilot studies of pulsating stars
involving both asteroseismic and interferometric constraints and look into the
future, summarizing ongoing efforts concerning the development of future
instruments and satellite missions which are expected to have an impact in this
field of research.


title: Galaxy Bulges at Mid and High-Redshift

abstract:
  Bulges are a major galaxy component in the nearby universe, and are one of
the primary features that differentiates and defines galaxies. The origin of
bulges can be directly probed in part by examining distant galaxies to search
for high redshift bulges, and to study the properties of bulges in formation.
We review the evidence for bulges at high redshift in this article, and how by
studying bulges through a variety of approaches, including morphological,
colour, and stellar mass selection, we can determine when and how these systems
assembled. We argue that the majority of the most massive 'classical' bulges
are in place by z ~ 1.5 - 2, and likely formed very early through major
mergers. Other, likely lower mass, bulges form through a secular process along
with their disks. Direct observations suggest that these two formation
processes are occurring, as spheroids are commonly seen at z > 1, as are disks
and spiral galaxies in the form of luminous diffuse objects, clump-clusters,
and chain galaxies. However, bulge+disk systems are relatively rare until z ~
1, suggesting that this structural assembly occurred relatively late.


title:
Comment on ``Passage Times for Unbiased Polymer Translocation through a
  Narrow Pore''

abstract:
  One of the most fundamental quantities associated with polymer translocation
through a nanopore is the translocation time $\tau$ and its dependence on the
chain length $N$. Our simulation results based on both the bond fluctuation
Monte Carlo and Molecular Dynamics methods confirm the original prediction
$\tau\sim N^{2\nu+1}$, which scales in the same manner as the Rouse relaxation
time of the chain except for a larger prefactor, and invalidates other scaling
claims.


title: Charm

abstract:
  New results on properties and decays of open charm and charmonium states are
reviewed. The emphasis is on examples that illustrate the various aspects
through which studies of charm physics impact the field.


title:
$C^*$-pseudo-Kac systems and duality for coactions of concrete Hopf
  $C^*$-bimodules

abstract:
  We study coactions of concrete Hopf $C^{*}$-bimodules in the framework of
(weak) $C^{*}$-pseudo-Kac systems, define reduced crossed products and dual
coactions, and prove an analogue of Baaj-Skandalis duality.


title: The deformation of the Whitham systems in the almost linear case

abstract:
  We consider the deformation of the Whitham systems in the case when the
initial system is close to linear one. It appears that the deformation
procedure should be modified in this special case to make all the constructions
stable in the linear limit. We suggest here the special deformation scheme
which gives the stable deformation of the Whitham system for the almost linear
initial systems.


title:
Gauge-invariant coherent states for Loop Quantum Gravity I: Abelian
  gauge groups

abstract:
  In this paper we investigate the properties of gauge-invariant coherent
states for Loop Quantum Gravity, for the gauge group U(1). This is done by
projecting the corresponding complexifier coherent states, which have been
applied in numerous occasions to investigate the semiclassical limit of the
kinematical sector, to the gauge-invariant Hilbert space. This being the first
step to construct physical coherent states, we arrive at a set of
gauge-invariant states that approximate well the gauge-invariant degrees of
freedom of abelian LQG. Furthermore, these states turn out to encode explicit
information about the graph topology, and show the same pleasant peakedness
properties known from the gauge-variant complexifier coherent states.


title:
Mott transition in one dimension: Benchmarking dynamical cluster
  approaches

abstract:
  The variational cluster approach (VCA) is applied to the one-dimensional
Hubbard model at zero temperature using clusters (chains) of up to ten sites
with full diagonalization and the Lanczos method as cluster solver. Within the
framework of the self-energy-functional theory (SFT), different cluster
reference systems with and without bath degrees of freedom, in different
topologies and with different sets of variational parameters are considered.
Static and one-particle dynamical quantities are calculated for half-filling as
a function of U as well as for fixed U as a function of the chemical potential
to study the interaction- and filling-dependent metal-insulator (Mott)
transition. The recently developed Q-matrix technique is used to compute the
SFT grand potential. For benchmarking purposes we compare the VCA results with
exact results available from the Bethe ansatz, with essentially exact dynamical
DMRG data, with (cellular) dynamical mean-field theory and full diagonalization
of isolated Hubbard chains. Several issues are discussed including convergence
of the results with cluster size, the ability of cluster approaches to access
the critical regime of the Mott transition, efficiency in the optimization of
correlated-site vs. bath-site parameters and of multi-dimensional parameter
optimization. We also study the role of bath sites for the description of
excitation properties and as charge reservoirs for the description of filling
dependencies. The VCA turns out to be a computationally cheap method which is
competitive with established cluster approaches.


title: H.E.S.S. observations of the supernova remnant RX J0852.0-4622

abstract:
  The shell-type supernova remnant RX J0852.0-4622 was detected in 2004 and
re-observed between December 2004 and May 2005 with the High Energy
Stereoscopic System (H.E.S.S.), an array of four Imaging Cherenkov Telescopes
located in Namibia and dedicated to the observations of gamma-rays above 100
GeV. The angular resolution of <0.1 degree and the large field of view of
H.E.S.S. (5 degrees diameter) are well adapted to studying the morphology of
the object in very high energy gamma-rays, which exhibits a remarkably thin
shell very similar to the features observed in the radio range and in X-rays.
The spectral analysis of the source from 300 GeV to 20 TeV will be presented.
Finally, the possible origins of the very high energy gamma-ray emission
(Inverse Compton scattering by electrons or the decay of neutral pions produced
by proton interactions) will be discussed, on the basis of morphological and
spectral features obtained at different wavelengths.


title: Dynamics and Hadronization at intermediate transverse momentum at RHIC

abstract:
  The ultra-relativistic heavy-ion program at RHIC has shown that at
intermediate transverse momenta ($p_T \simeq 2$-6 GeV) standard (independent)
parton fragmentation can neither describe the observed baryon-to-meson ratios
nor the empirical scaling of the hadronic elliptic flow ($v_2$) according to
the number of valence quarks. Both aspects find instead a natural explanation
in a coalescence plus fragmentation approach to hadronization. After a brief
review of the main results for light quarks, we focus on heavy quarks showing
that a combined fragmentation and quark-coalescence framework is relevant also
here. Moreover, within relativistic Langevin simulations we find evidence for
the importance of heavy-light resonances in the Quark-Gluon Plasma (QGP) to
explain the strong energy loss and collective flow of heavy-quark spectra as
inferred from non-photonic electron observables. Such heavy-light resonances
can pave the way to a unified understanding of the microscopic structure of the
QGP and its subsequent hadronization by coalescence.


title: Low energy polarization sensitivity of the Gas Pixel Detector

abstract:
  An X-ray photoelectric polarimeter based on the Gas Pixel Detector has been
proposed to be included in many upcoming space missions to fill the gap of
about 30 years from the first (and to date only) positive measurement of
polarized X-ray emission from an astrophysical source. The estimated
sensitivity of the current prototype peaks at an energy of about 3 keV, but the
lack of readily available polarized sources in this energy range has prevented
the measurement of detector polarimetric performances.
  In this paper we present the measurement of the Gas Pixel Detector
polarimetric sensitivity at energies of a few keV and the new, light, compact
and transportable polarized source that was devised and built to this aim.
Polarized photons are produced, from unpolarized radiation generated with an
X-ray tube, by means of Bragg diffraction at nearly 45 degrees.
  The employment of mosaic graphite and flat aluminum crystals allow the
production of nearly completely polarized photons at 2.6, 3.7 and 5.2 keV from
the diffraction of unpolarized continuum or line emission. The measured
modulation factor of the Gas Pixel Detector at these energies is in good
agreement with the estimates derived from a Monte Carlo software, which was up
to now employed for driving the development of the instrument and for
estimating its low energy sensitivity. In this paper we present the excellent
polarimetric performance of the Gas Pixel Detector at energies where the peak
sensitivity is expected. These measurements not only support our previous
claims of high sensitivity but confirm the feasibility of astrophysical X-ray
photoelectric polarimetry.


title:
Leptogenesis with exclusively low-energy CP Violation in the Context of
  Minimal Lepton Flavour Violation

abstract:
  We analyze lepton flavour violation (LFV) and the generation of the observed
baryon-antibaryon asymmetry of the Universe (BAU) within a generalized minimal
lepton flavour violation framework with three quasi-degenerate heavy Majorana
neutrinos. The BAU which is obtained through radiative resonant leptogenesis
can successfully be generated widely independent of the Majorana scale in this
scenario and flavour effects are found to be relevant. Then we discuss the
specific case in which CP violation is exclusively present at low-energies (a
real R matrix) in the flavour sensitive temperature regime. Successful
leptogenesis in this case leads to strong constraints on low-energy neutrino
parameters.


title: Transversity Measurements at COMPASS

abstract:
  The measurement of transverse spin effects in semi-inclusive deep-inelastic
scattering is an important part of the COMPASS physics program. From the
analysis of the 2002-2004 data, new results for the transverse target spin
asymmetry of z-ordered identified pion and kaon pairs are presented. In
addition, a first result for the transverse target spin asymmetry of
exclusively produced rho^0 mesons on the deuteron is shown.


title:
Global regularity for a Birkhoff-Rott-alpha approximation of the
  dynamics of vortex sheets of the 2D Euler equations

abstract:
  We present an alpha-regularization of the Birkhoff-Rott equation, induced by
the two-dimensional Euler-alpha equations, for the vortex sheet dynamics. We
show that initially smooth self-avoiding vortex sheet remains smooth for all
times under the alpha-regularized dynamics, provided the initial density of
vorticity is an integrable function over the curve with respect to the
arc-length measure.


title:
Statistical analysis of neutrino events from SN1987A neutrino burst:
  estimation of the electron antineutrino mass

abstract:
  The method of the statistical sample moments was used for the analysis of
neutrino events from SN1987A burst in Cherenkov detectors. In particular the
coefficients of correlation $Q(E,t)$ between the energies $E$ of electron
antineutrinos $\bar \nu_e$ emitted by star and the ejection instants $t$ of
$\bar \nu_e$ for neutrino events recorded by Cherenkov water detectors of KII
and IMB collaborations were calculated. $Q(E,t)$ values depend on the assumed
mass of $\bar \nu_e$. Modern model of the gravitational stellar core collapse
with an accretion phase predicts the low level of such correlation $<Q(E,t)>$
averaged with respect to neutrino burst. On condition that empirical $Q(E,t)$
values equal the theoretical model quantities $<Q(E,t)>$ one can obtain
$22\pm10 eV/c^{2}$ as an estimate of the nonzero $\bar \nu_e$ mass. The error
of this estimate implies that $\bar \nu_e$ mass less than $2 eV/c^2$ is
unlikely. The laboratry data of the tritium $\beta$-decay agree adequately with
the presented astrophysical estimate provided that the anomalous structure near
the end point of $\beta$-spectrum is taken into account.


title: Precision Lattice Calculation of D and Ds decay constants

abstract:
  We present a determination of the decay constants of the $D$ and $D_s$ mesons
from lattice QCD, each with a total error of about 2%, approximately a factor
of three better than previous calculations. We have been able to achieve this
through the use of a highly improved discretization of QCD for charm quarks,
coupled to gauge configurations generated by the MILC collaboration that
include the full effect of sea u, d, and s quarks. We have results for a range
of u/d masses down to m_s/5 and three values of the lattice spacing, which
allow us to perform accurate continuum and chiral extrapolations. We fix the
charm quark mass to give the experimental value of the \eta_c mass, and then a
stringent test of our approach is the fact that we obtain correct (and
accurate) values for the mass of the D and D_s mesons. We compare f_D and
f_{D_s} with f_K and f_\pi, and using experiment determine corresponding CKM
elements with good precision.


title: Scanning tunneling spectroscopy with superconducting tips of Al

abstract:
  We present Scanning Tunneling Spectroscopy measurements at 0.1 K using tips
made of Al. At zero field, the atomic lattice and charge density wave of
2HNbSe2 are observed, and under magnetic fields the peculiar electronic surface
properties of vortices are precisely resolved. The tip density of states is
influenced by the local magnetic field of the vortex, providing for a new probe
of the magnetic field at nanometric sizes.


title: Domain-wall and overlap fermions at nonzero quark chemical potential

abstract:
  We have recently given a construction of the overlap Dirac operator at
nonzero quark chemical potential. Here, we introduce a quark chemical potential
in the domain-wall fermion formalism and show that our earlier result is
reproduced if the extent of the fifth dimension is taken to infinity and its
lattice spacing is taken to zero. We also extend this result to include a bare
quark mass, consider its continuum limit, and prove a number of properties of
the overlap operator at nonzero quark chemical potential. In particular, we
show that the relation between the anomaly and the index of the overlap
operator remains valid.


title:
Dynamics of the triple contact line on a non-isothermal heater at
  partial wetting

abstract:
  The dynamics of the triple gas-liquid-solid contact line is analysed for the
case where the gas is the saturated vapour corresponding to the liquid, like in
the vapour bubble in boiling. It is shown that even small superheating (with
respect to the saturation temperature) causes evaporation of the adsorption
liquid film and the true triple contact is established. It is shown that the
hydrodynamic contact line singularity cannot be relaxed with the Navier slip
condition under such circumstances. Augmented with the second derivative slip
condition is proposed to be applied. For the partial wetting conditions, a
non-stationary contact line problem where the contact line motion is caused by
evaporation or condensation is treated in the lubrication approximation in the
vicinity of the contact line. High heat fluxes in this region require the
transient heat conduction inside the heater to be accounted for. Two 2D
problems, those of drop retraction with no phase change and of drop evaporation
are solved and analysed as illustrations of the proposed approach.


title: N=1 4D Supermembrane from 11D

abstract:
  The action of the 11D supermembrane with nontrivial central charges
compactified on a 7D toroidal manifold is obtained. It describes a
supermembrane evolving in a 4d Minkowski space-time. The action is invariant
under additional symmetries in comparison to the supermembrane on a Minkowski
target space. The hamiltonian in the LCG is invariant under conformal
transformations on the Riemann surface base manifold. The spectrum of the
regularized hamiltonian is discrete with finite multiplicity. Its resolvent is
compact. Susy is spontaneously broken, due to the topological central charge
condition, to four supersymmetries in 4D, the vacuum belongs to an N=1
supermultiplet. When assuming the target-space to be an isotropic 7-tori, the
potential does not contain any flat direction, it is stable on the moduli space
of parameters.


title:
SUSY Associated Vector Coherent States and Generalized Landau Levels
  Arising From 2-dimensional SUSY

abstract:
  We describe a method for constructing vector coherent states for quantum
supersymmetric partner Hamiltonians. The method is then applied to such partner
Hamiltonians arising from a generalization of the fractional quantum Hall
effect. Explicit examples are worked out.


title: Lepton mass effects in weak CC single pion production

abstract:
  Different approaches to take into account nonzero lepton mass in the
Rein-Sehgal model are compared. Modification of the axial current due to pion
pole term are included and it is shown that they lead to large reduction of
antineutrino cross section and a change of the shape of $d\sigma/dQ^2$.


title: Color superconductivity in dense quark matter

abstract:
  Matter at high density and low temperature is expected to be a color
superconductor, which is a degenerate Fermi gas of quarks with a condensate of
Cooper pairs near the Fermi surface that induces color Meissner effects. At the
highest densities, where the QCD coupling is weak, rigorous calculations are
possible, and the ground state is a particularly symmetric state, the
color-flavor locked (CFL) phase. The CFL phase is a superfluid, an
electromagnetic insulator, and breaks chiral symmetry. The effective theory of
the low-energy excitations in the CFL phase is known and can be used, even at
more moderate densities, to describe its physical properties. At lower
densities the CFL phase may be disfavored by stresses that seek to separate the
Fermi surfaces of the different flavors, and comparison with the competing
alternative phases, which may break translation and/or rotation invariance, is
done using phenomenological models. We review the calculations that underlie
these results, and then discuss transport properties of several
color-superconducting phases and their consequences for signatures of color
superconductivity in neutron stars.

categories: hep-ph astro-ph cond-mat.supr-con nucl-th


title:
Gauge-invariant coherent states for Loop Quantum Gravity II: Non-abelian
  gauge groups

abstract:
  This is the second paper concerning gauge-invariant coherent states for Loop
Quantum Gravity. Here, we deal with the gauge group SU(2), this being a
significant complication compared to the abelian U(1) case encountered in the
previous article. We study gauge-invariant coherent states on certain special
graphs by analytical and numerical methods. We find that their overlap is
Gauss-peaked in gauge-invariant quantities, as long as states are not labeled
by degenerate gauge orbits, i.e. points where the gauge-invariant configuration
space has singularities. In these cases the overlaps are still concentrated
around these points, but the peak profile exhibits a plateau structure. This
shows how the semiclassical properties of the states are influenced by the
geometry of the gauge-invariant phase space.


title: SU(4)_C X SU(2)_L X SU(2)_R Models With C-parity

abstract:
  We construct supersymmetric SU(4)_C X SU(2)_L X SU(2)_R models with
spontaneously broken left-right symmetry (C-parity). The minimal supersymmetric
standard model (MSSM) can be recovered at low scales by exploiting the missing
partner mechanism. The field content is compatible with realistic fermion
masses and mixings, proton lifetime is close to or exceeds the current
experimental bounds, and supersymmetric hybrid inflation can be implemented to
take care of C-parity domain walls as well as magnetic monopoles, and to
realize the observed baryon asymmetry via non-thermal leptogenesis.


title:
Multiparticle SUSY simulations at LHC & ILC: Off-Shell effects,
  interferences and radiative corrections

abstract:
  The interesting but difficult phenomenology of supersymmetric models at the
LHC and ILC demands a corresponding complexity and maturity from simulation
tools. This includes multi-particle final states, reducible and irreducible
backgrounds, spin correlations, real emission of photons and gluons, virtual
corrections etc. Most of these topics are included in the multi-particle Monte
Carlo (MC) Event generators Madgraph, WHIZARD and Sherpa. A comparison of these
codes is shown, with a special focus on the new release of WHIZARD. I show
examples for the necessity of considering full matrix elements with all
off-shell effects and interferences for multi-particle final states in
supersymmetric models and give a status report on ongoing projects for
simulations of SUSY processes at the LHC with these codes, including all of the
abovementioned corrections.


title:
Hadronic loop contributions to $J/\psi$ and $\psi^\prime$ radiative
  decays into $\gamma\eta_c$ or $\gamma\eta_c^\prime$

abstract:
  Intermediate hadronic meson loop contributions to $J/\psi$, $\psi^\prime \to
\gamma\eta_c$ ($\gamma\eta_c^\prime$) are studied apart from the dominant M1
transitions in an effective Lagrangian approach. Due to the property of the
unique antisymmetric tensor coupling in $V\to VP$, the hadronic loop
transitions provide explicit corrections to the M1 transition amplitudes
derived from the naive "quenched" $c\bar{c}$ transitions via the coupling form
factors. This mechanism interfering with the M1 transition amplitudes naturally
accounts for the deviations from the Godfrey-Isgur model predictions in
$J/\psi$ and $\psi^\prime\to \gamma\eta_c$. It also predicts a small branching
ratio of $\psi^\prime\to \gamma\eta_c^\prime$, which can be examined by
experimental measurements at BES and CLEO-c.


title:
Two populations are better than one: Short gamma-ray bursts from SGR
  giant flares and NS-NS mergers

abstract:
  With a peak luminosity of ~10^47 erg/s, the December 27th 2004 giant flare
from SGR1806-20 would have been visible by BATSE (the Burst and Transient
Source Experiment) out to ~50 Mpc. It is thus plausible that some fraction of
the short duration Gamma-Ray Bursts (sGRBs) in the BATSE catalogue were due to
extragalactic magnetar giant flares. According to the most widely accepted
current models, the remaining BATSE sGRBs were most likely produced by compact
object (neutron star-neutron star or neutron star-black hole) mergers with
intrinsically higher luminosities. Previously, by examining correlations on the
sky between BATSE sGRBs and galaxies within 155 Mpc, we placed limits on the
proportion of nearby sGRBs. Here, we examine the redshift distribution of sGRBs
produced by assuming both one and two populations of progenitor with separate
Luminosity Functions (LFs). Using the local Galactic SGR giant flare rate and
theoretical NS-NS merger rates evolved according to well-known Star Formation
Rate parameterisations, we constrain the predicted distributions by BATSE sGRB
overall number counts. We show that only a dual population consisting of both
SGR giant flares and NS-NS mergers can reproduce the likely local distribution
of sGRBs as well as the overall number counts. In addition, the best fit LF
parameters of both sub-populations are in good agreement with observed
luminosities.


title: Adiabaticity and spectral splits in collective neutrino transformations

abstract:
  Neutrinos streaming off a supernova core transform collectively by
neutrino-neutrino interactions, leading to "spectral splits" where an energy
E_split divides the transformed spectrum sharply into parts of almost pure but
different flavors. We present a detailed description of the spectral split
phenomenon which is conceptually and quantitatively understood in an adiabatic
treatment of neutrino-neutrino effects. Central to this theory is a
self-consistency condition in the form of two sum rules (integrals over the
neutrino spectra that must equal certain conserved quantities). We provide
explicit analytic and numerical solutions for various neutrino spectra. We
introduce the concept of the adiabatic reference frame and elaborate on the
relative adiabatic evolution. Violating adiabaticity leads to the spectral
split being "washed out". The sharpness of the split appears to be represented
by a surprisingly universal function.


title: Multipartite entanglement in four-qubit cluster-class states

abstract:
  Based on quantitative complementarity relations (QCRs), we analyze the
multipartite correlations in four-qubit cluster-class states. It is proven
analytically that the average multipartite correlation $E_{ms}$ is entanglement
monotone. Moreover, it is also shown that the mixed three-tangle is a
correlation measure compatible with the QCRs in this kind of quantum states.
More arrestingly, with the aid of the QCRs, a set of hierarchy entanglement
measures is obtained rigorously in the present system.


title:
Periodic solutions of periodically perturbed planar autonomous systems:
  A topological approach

abstract:
  Aim of this paper is to investigate the existence of periodic solutions of a
nonlinear planar autonomous system having a limit cycle x_0 of least period
T_0>0 when it is perturbed by a small parameter, T_1-periodic, perturbation. In
the case when T_0/T_1 is a rational number l/k, with l, k prime numbers, we
provide conditions to guarantee, for the parameter perturbation e>0
sufficiently small, the existence of klT_0-periodic solutions x_e of the
perturbed system which converge to the trajectory x_1 of the limit cycle as
e->0. Moreover, we state conditions under which T=klT_0 is the least period of
the periodic solutions x_e. We also suggest a simple criterion which ensures
that these conditions are verified. Finally, in the case when T_0/T_1 is an
irrational number we show the nonexistence, whenever T>0 and e>0, of T-periodic
solutions x_e of the perturbed system converging to x_1. The employed methods
are based on the topological degree theory.


title:
Conditional preparation of states containing a definite number of
  photons

abstract:
  A technique for conditionally creating single- or multimode photon-number
states is analyzed using Bayesian theory. We consider the heralded N-photon
states created from the photons produced by an unseeded optical parametric
amplifier when the heralding detector is the time-multiplexed
photon-number-resolving detector recently demonstrated by Fitch, et al. [Phys.
Rev. A 68, 043814 (2003).] and simultaneously by Achilles, et al. [Opt. Lett.
28, 2387 (2003).]. We find that even with significant loss in the heralding
detector, fields with sub-Poissonian photon-number distributions can be
created. We also show that heralded multimode fields created using this
technique are more robust against detector loss than are single-mode fields.


title: Contracting Endomorphisms and Gorenstein Modules

abstract:
  We characterize Gorenstein modules over those local rings that admit a finite
contracting endomorphism.


title: Positve Entropy Geodesic Flows on Nilmanifolds

abstract:
  Let T be the nilpotent group of 4 x 4 real upper triangular matrices. In this
note we show that the Euler equations of certain left-invariant riemannian
metrics on T have a horseshoe. We also show, with the aid of a numerical
computation of a Melnikov-type integral, that the Euler equations of the
sub-riemannian Carnot metric on T has a horseshoe. This sharpens an earlier
result of Montgomery, Shapiro and Stolin who had shown that the equations are
algebraically non-integrable.


title:
Electrostatics in Periodic Boundary Conditions and Real-space
  Corrections

abstract:
  We address periodic-image errors arising from the use of periodic boundary
conditions to describe systems that do not exhibit full three-dimensional
periodicity. The difference between the periodic potential, as
straightforwardly obtained from a Fourier transform, and the potential
satisfying any other boundary conditions can be characterized analytically. In
light of this observation, we present an efficient real-space method to correct
periodic-image errors, based on a multigrid solver for the potential
difference, and demonstrate that exponential convergence of the energy with
respect to cell size can be achieved in practical calculations. Additionally,
we derive rapidly convergent expansions for determining the Madelung constants
of point-charge assemblies in one, two, and three dimensions.


title:
Spectral properties of the non-hermitian Wilson-Dirac operator in the
  Schroedinger functional

abstract:
  We report on some preparatory investigations for the simulation of the QCD
Schroedinger functional with a non-hermitian polynomial hybrid Monte Carlo
algorithm. The complex spectrum of the non-hermitean free operator with SF
boundary condititons is computed semianalytically. Then it is shown how one can
obtain relevant information on the boundary of the spectral domain also in the
presence of nontrivial gaugefields by monitoring the behavior of polynomials in
the Wilson operator applied on random vectors.


title: Factorizations of one dimensional classical systems

abstract:
  A class of one dimensional classical systems is characterized from an
algebraic point of view. The Hamiltonians of these systems are factorized in
terms of two functions that together with the Hamiltonian itself close a
Poisson algebra. These two functions lead directly to two time-dependent
integrals of motion from which the phase motions are derived algebraically. The
systems so obtained constitute the classical analogues of the well known
factorizable one dimensional quantum mechanical systems.


title: CP Violation and Neutrino Masses and Mixings from Quark Mass Hierarchies

abstract:
  We study the connection between quark and lepton mass matrices in a
supersymmetric SO(10) GUT model in six dimensions, compactified on an orbifold.
The physical quarks and leptons are mixtures of brane and bulk states. This
leads to a characteristic pattern of mass matrices and high-energy CP violating
phases. The hierarchy of up and down quark masses determines the CKM matrix and
most charged lepton and neutrino masses and mixings. The small hierarchy of
neutrino masses is a consequence of the mismatch of the up and down quark mass
hierarchies. The effective CP violating phases in the quark sector, neutrino
oscillations and leptogenesis are unrelated. In the neutrino sector we can
accomodate naturally $\sin \theta_{23} \sim 1$, $\sin \theta_{13} \lesssim 0.1$
and $m_1 \lesssim m_2 \sim \sqrt{\Delta m^2_\text{sol}} < m_3 \sim \sqrt{\Delta
m^2_\text{atm}}$.


title:
Comment on "Is There a "Most Perfect Fluid" Consistent with Quantum
  Field Theory?"

abstract: This is a comment on hep-th/0702136


title:
Asymmetry of rotational catalysis of single membrane-bound F0F1-ATP
  synthase

abstract: Erroneous submission in violation of copyright removed by arXiv admin.


title: On superstatistical multiplicative-noise processes

abstract:
  In this manuscript we analyse the long-term probability density function of
non-stationary dynamical processes which are enclosed inward the Feller class
of processes with time varying exponents for multiplicative noise. The update
in the value of the exponent occurs in the same conditions presented by Beck
and Cohen for superstatistics. Moreover, we are able to provide a dynamical
scenario for the emergence of a generalisation of the Weibull distribution
previously introduced.


title: Deuteron Momentum Distribution in KD2HPO4

abstract:
  The momentum distribution in KD2PO4(DKDP) has been measured using neutron
Compton scattering above and below the weakly first order
paraelectric-ferroelectric phase transition(T=229K). There is very litte
difference between the two distributions, and no sign of the coherence over two
locations for the proton observed in the paraelectric phase, as in KH2PO4(KDP).
We conclude that the tunnel splitting must be much less than 20mev. The width
of the distribution indicates that the effective potential for DKDP is
significantly softer than that for KDP. As electronic structure calculations
indicate that the stiffness of the potential increases with the size of the
coherent region locally undergoing soft mode fluctuations, we conclude that
there is a mass dependent quantum coherence length in both systems.


title: Mining for trees in a graph is NP-complete

abstract: Mining for trees in a graph is shown to be NP-complete.


title:
Nonextensive statistical mechanics and central limit theorems I -
  Convolution of independent random variables and q-product

abstract:
  In this article we review the standard versions of the Central and of the
Levy-Gnedenko Limit Theorems, and illustrate their application to the
convolution of independent random variables associated with the distribution
known as q-Gaussian. This distribution emerges upon extremisation of the
nonadditive entropy, basis of nonextensive statistical mechanics. It has a
finite variance for q < 5/3, and an infinite one for q > 5/3. We exhibit that,
in the case of (standard) independence, the q-Gaussian has either the Gaussian
(if q < 5/3) or the a-stable Levy distributions (if q > 5/3) as its attractor
in probability space. Moreover, we review a generalisation of the product, the
q-product, which plays a central role in the approach of the specially
correlated variables emerging within the nonextensive theory.


title: Power-law Behavior of High Energy String Scatterings in Compact Spaces

abstract:
  We calculate high energy massive scattering amplitudes of closed bosonic
string compactified on the torus. We obtain infinite linear relations among
high energy scattering amplitudes. For some kinematic regimes, we discover that
some linear relations break down and, simultaneously, the amplitudes enhance to
power-law behavior due to the space-time T-duality symmetry in the compact
direction. This result is consistent with the coexistence of the linear
relations and the softer exponential fall-off behavior of high energy string
scattering amplitudes as we pointed out prevously. It is also reminiscent of
hard (power-law) string scatterings in warped spacetime proposed by Polchinski
and Strassler.


title: Structure Factor of the 3D Random Field XY Model

abstract:
  We have performed Monte Carlo studies of the 3D random field XY model on $L
\times L \times L$ simple cubic lattices, with random field strengths of $h_r$
= 1 and 2. We present results for the angle-averaged magnetic structure factor,
$S (k)$ at $L = 64$. Our results appear to indicate a phase transition into a
ferromagnetic state. This is made possible by the existence of a Griffiths
singularity. It appears that at the phase transition $M^2$ jumps to zero
discontinuously, with a latent heat which is probably subextensive.


title:
Stellar Populations Found in the Central kpc of Four Luminous Compact
  Blue Galaxies at Intermediate Redshift

abstract:
  We investigate the star formation history of the central regions of four
Luminous Compact Blue Galaxies (LCBGs). LCBGs are blue (B-V<0.6), compact
(MU_B<21.5 mag arcsec^-2) galaxies with absolute magnitudes M_B brighter than
-17.5. The LCBGs analyzed here are located at 0.436<z<0.525. They are among the
most luminous (M_B < -20.5), blue (B-V < 0.4) and high surface brightness (MU_B
< 19.0 mag arcsec^-2) of this population. The observational data used were
obtained with the HST/STIS spectrograph, the HST/WF/PC-2 camera and the
HST/NICMOS first camera. We find evidence for multiple stellar populations. One
of them is identified as the ionizing population, and the other one corresponds
to the underlying stellar generation.
  The estimated masses of the inferred populations are compatible with the
dynamical masses, which are typically 2--10x 10^9 M_sun. Our models also
indicate that the first episodes of star formation the presented LCBGs
underwent happened between 5 and 7 Gyr ago.
  We compare the stellar populations found in LCBGs with the stellar
populations present in bright, local HII galaxies, nearby spheroidal systems
and Blue Compact Dwarf Galaxies. It turns out that the underlying stellar
populations of LCBGs are similar yet bluer to those of local HII galaxies. It
is also the case that the passive color evolution of the LCBGs could convert
them into local Spheroidal galaxies if no further episode of star formation
takes place. Our results help to impose constraints on evolutionary scenarios
for the population of LCBGs found commonly at intermediate redshifts.


title: Operating molecular transistors as heat pumps

abstract:
  We study heat transport in transistor-like devices composed of two reservoirs
and a gate electrode, with a ballistic electronic one-dimensional system
connected between the two reservoirs and interacting with a laser field. We
derive in a simple way an equation for the heat flux in terms of the
Floquet-Green operator of the system. As a case example, we investigate a
two-level transistor and find that the laser field can produce a net heat flow
out of either one of the reservoirs. The direction of this flow is determined
by the gate voltage. We study numerically the dependence of this heat-pump on
the relevant parameters of the system and show that there is a minimum
temperature below which it does not operate.


title:
Nonextensive statistical mechanics and central limit theorems II -
  Convolution of q-independent random variables

abstract:
  In this article we review recent generalisations of the central limit theorem
for the sum of specially correlated (or q-independent) variables, focusing on q
greater or equal than 1. Specifically, this kind of correlation turns the
probability density function known as q-Gaussian, which emerges upon
maximisation of the entropy Sq, into an attractor in probability space.
Moreover, we also discuss a q-generalisation of a-stable Levy distributions
which can as well be stable for this special kind of correlation.Within this
context, we verify the emergence of a triplet of entropic indices which relate
the form of the attractor, the correlation, and the scaling rate, similar to
the q-triplet that connects the entropic indices characterising the sensitivity
to initial conditions, the stationary state, and relaxation to the stationary
state in anomalous systems.


title: Spectroscopy of new c,b-mesons

abstract:
  Masses of the lowest multiplets of c,b-mesons in S- and P-wave states with
quantum numbers JPC: 0-+, 1--, 0++, 1+-, 1++, 2++ are obtained with the help of
dispersion N/D method of heavy quark effective theory. The results are in a
good agreement with experimental data. Radiative decay widths for some states
mentioned above were calculated.


title: Electron coherence at low temperatures: The role of magnetic impurities

abstract:
  We review recent experimental progress on the saturation problem in metallic
quantum wires. In particular, we address the influence of magnetic impurities
on the electron phase coherence time. We also present new measurements of the
phase coherence time in ultra-clean gold and silver wires and analyse the
saturation of \tauphi in these samples, cognizant of the role of magnetic
scattering. For the cleanest samples, Kondo temperatures below 1 mK and
extremely-small magnetic-impurity concentration levels of less than 0.08 ppm
have to be assumed to attribute the observed saturation to the presence of
magnetic impurities.


title:
An asymptotic-numerical approach for examining global solutions to an
  ordinary differential equation

abstract:
  Purely numerical methods do not always provide an accurate way to find all
the global solutions to nonlinear ODE on infinite intervals. For example,
finite-difference methods fail to capture the asymptotic behavior of solutions,
which might be critical for ensuring global existence. We first show, by way of
a detailed example, how asymptotic information alone provides significant
insight into the structure of global solutions to a nonlinear ODE. Then we
propose a method for providing this missing asymptotic data to a numerical
solver, and show how the combined approach provides more detailed results than
either method alone.


title: New Dual Conformally Invariant Off-Shell Integrals

abstract:
  Evidence has recently emerged for a hidden symmetry of scattering amplitudes
in N=4 super Yang-Mills theory called dual conformal symmetry. At weak coupling
the presence of this symmetry has been observed through five loops, while at
strong coupling the symmetry has been shown to have a natural interpretation in
terms of a T-dualized AdS_5. In this paper we study dual conformally invariant
off-shell four-point Feynman diagrams. We classify all such diagrams through
four loops and evaluate 10 new off-shell integrals in terms of Mellin-Barnes
representations, also finding explicit expressions for their infrared
singularities.


title:
Low Temperature Shear Modulus Changes in Solid 4-He and Connection to
  Supersolidity

abstract:
  Superfluidity, liquid flow without friction, is familiar in helium. The first
evidence for "supersolidity", its analogue in quantum solids, came from recent
torsional oscillator (TO) measurements involving 4-He. At temperatures below
200 mK, TO frequencies increased, suggesting that some of the solid decoupled
from the oscillator. This behavior has been replicated by several groups but
solid 4-He does not respond to pressure differences and persistent currents and
other signatures of superflow have not been seen. Both experiments and theory
indicate that defects are involved. These should also affect the solid's
mechanical behavior and so we have measured the shear modulus of solid 4-He at
low frequencies and strains. We observe large increases below 200 mK, with the
same dependence on measurement amplitude, 3-He impurity concentration and
annealing as the decoupling seen in TO experiments. This unusual elastic
behavior is explained in terms of a dislocation network which is pinned by 3-He
at the lowest temperatures but becomes mobile above 100 mK. The frequency
changes in TO experiments appear to be related to the motion of these
dislocations, perhaps by disrupting a possible supersolid state.


title: The Distance and Age of the SNR Kes 73 and AXP 1E 1841-045

abstract:
  We provide a new distance estimate to the supernova remnant (SNR) Kes 73 and
its associated anomalous X-ray pulsar (AXP) 1E 1841-045. 21 cm HI images and HI
absorption/ emission spectra from new VLA observations, and 13CO emission
spectra of Kes 73 and two adjacent compact HII regions (G27.276+0.148 and
G27.491+0.189) are analyzed. The HI images show prominent absorption features
associated with Kes 73 and the HII regions. The absorption appears up to the
tangent point velocity giving a lower distance limit to Kes 73 of 7.5 kpc,
which has previously been given as the upper limit. Also, G27.276+0.148 and
G27.491+0.189 are at the far kinematic distances of their radio recombination
line velocities. There is prominent HI emission in the range 80--90 km/s for
all three objects. The two HII regions show HI absorption at ~ 84 km/s, but
there is no absorption in the Kes 73 absorption spectrum. This implies an upper
distance limit of ~ 9.8 kpc to Kes 73. This corrected larger distance to Kes
73/ AXP 1E 1841-045 system leads to a refined age of the SNR of 500 to 1000 yr,
and a ~ 50% larger AXP X-ray luminosity.


title:
Consequences of the Gross/Zagier formulae: Stability of average
  L-values, subconvexity, and non-vanishing mod p

abstract:
  In this paper we investigate some consequences of the Gross/Zagier types of
formulae which were introduced by Gross and Zagier, and were then generalized
in various directions by Hatcher, Zhang, Kudla and several other people.
Working in the classical context of central values of L-series of holomorphic
forms of prime level, we deduce an exact average formula for suitable twists of
such L-values, with a relation to the class number of associated imaginary
quadratic fieds, thereby strengthening a result of Duke. One also obtains a
stability result, as well as subconvexity (in this setting), and certian
non-vanishing assertions. This article is dedicated to the memory of Serge
Lang.


title: The Extended Edit Distance Metric

abstract:
  Similarity search is an important problem in information retrieval. This
similarity is based on a distance. Symbolic representation of time series has
attracted many researchers recently, since it reduces the dimensionality of
these high dimensional data objects. We propose a new distance metric that is
applied to symbolic data objects and we test it on time series data bases in a
classification task. We compare it to other distances that are well known in
the literature for symbolic data objects. We also prove, mathematically, that
our distance is metric.


title: Search for Lorentz and CPT Violation Effects in Muon Spin Precession

abstract:
  The spin precession frequency of muons stored in the $(g-2)$ storage ring has
been analyzed for evidence of Lorentz and CPT violation. Two Lorentz and CPT
violation signatures were searched for: a nonzero $\Delta\omega_{a}$
(=$\omega_{a}^{\mu^{+}}-\omega_{a}^{\mu^{-}}$); and a sidereal variation of
$\omega_{a}^{\mu^{\pm}}$. No significant effect is found, and the following
limits on the standard-model extension parameters are obtained: $b_{Z} =-(1.0
\pm 1.1)\times 10^{-23}$ GeV; $(m_{\mu}d_{Z0}+H_{XY}) = (1.8 \pm 6.0 \times
10^{-23})$ GeV; and the 95% confidence level limits
$\check{b}_{\perp}^{\mu^{+}}< 1.4 \times 10^{-24}$ GeV and
$\check{b}_{\perp}^{\mu^{-}} < 2.6 \times 10^{-24}$ GeV.


title:
Secrecy Capacity Region of a Multi-Antenna Gaussian Broadcast Channel
  with Confidential Messages

abstract:
  In wireless data networks, communication is particularly susceptible to
eavesdropping due to its broadcast nature. Security and privacy systems have
become critical for wireless providers and enterprise networks. This paper
considers the problem of secret communication over the Gaussian broadcast
channel, where a multi-antenna transmitter sends independent confidential
messages to two users with information-theoretic secrecy. That is, each user
would like to obtain its own confidential message in a reliable and safe
manner. This communication model is referred to as the multi-antenna Gaussian
broadcast channel with confidential messages (MGBC-CM). Under this
communication scenario, a secret dirty-paper coding scheme and the
corresponding achievable secrecy rate region are first developed based on
Gaussian codebooks. Next, a computable Sato-type outer bound on the secrecy
capacity region is provided for the MGBC-CM. Furthermore, the Sato-type outer
bound prove to be consistent with the boundary of the secret dirty-paper coding
achievable rate region, and hence, the secrecy capacity region of the MGBC-CM
is established. Finally, two numerical examples demonstrate that both users can
achieve positive rates simultaneously under the information-theoretic secrecy
requirement.


title:
Einstein, Sciascia, Majorana, Amaldi, e il Rapporto tra Intellettuali e
  Potere (Einstein, Sciascia, Majorana, Amaldi, and the Relationship of
  Intellectuals with the Power)

abstract:
  In Europe (e.g., in Italy), and in the States, the opinion is widely
spreading that the negative consequences of modern progress are the fault of
"Science". A lively debate on this topic took place among the famous writer
Leonardo Sciascia and Italian physicists like Edoardo Amaldi and Emilio Segre',
when Sciascia wrote his known book about the disappearance of Ettore Majorana,
a book that presented Majorana (a very reserved theoretical physicist) as an
example of the scientist that keeps his discoveries secret when afraid of
possible evil applications. We wish to contribute now to such a question, since
many special meetings did recently return to it, while celebrating the
centenary of Majorana's birth (2006), or 30 years (2005) from Sciascia's book
publication. It appeared natural to us to start with the figure of Einstein,
who, even if extremely peaceable, supported the atomic bomb construction by his
letter to Roosvelt. We discuss first the significance of part of Einsteins's
scientific work (which flourished in particular one century ago): We seize this
opportunity for presenting a derivation of the "twins paradox", so simple that
it has been taught to Senior High School last-year students or University
undergraduate students; all the present work, more in general, is addressed
mainly to them. In the second part of this paper, we analyse the general
meaning of Einstein's contributions to philosophy and pedagogy. The third part
is entirely devoted to our main subject, i.e., to discussing the
"Responsibility of the Intellectuals". The reader interested chiefly in this
last part, can find it re-expounded in a self-contained way in the Appendix.
More information in the Contents of this article.


title: D-branes, obstructed curves, and minimal model superpotentials

abstract:
  In this short note we apply methods of Aspinwall-Katz to compute
superpotentials of D-branes wrapped on more general obstructed rational curves
in Calabi-Yau threefolds. We find an a priori unexpected match between
superpotentials from certain such curves and the superpotentials of
Landau-Ginzburg models corresponding to minimal models.


title:
Possible way out of the Hawking paradox: Erasing the information at the
  horizon

abstract:
  We show that small deviations from spherical symmetry, described by means of
exact solutions to Einstein equations, provide a mechanism to "bleach" the
information about the collapsing body as it falls through the aparent horizon,
thereby resolving the information loss paradox. The resulting picture and its
implication related to the Landauer's principle in the presence of a
gravitational field, is discussed.


title:
Measurement of the ac Stark shift with a guided matter-wave
  interferometer

abstract:
  We demonstrate the effectiveness of a guided-wave Bose-Einstein condensate
interferometer for practical measurements. Taking advantage of the large arm
separations obtainable in our interferometer, the energy levels of the 87Rb
atoms in one arm of the interferometer are shifted by a calibrated laser beam.
The resulting phase shifts are used to determine the ac polarizability at a
range of frequencies near and at the atomic resonance. The measured values are
in good agreement with theoretical expectations. However, we observe a
broadening of the transition near the resonance, an indication of collective
light scattering effects. This nonlinearity may prove useful for the production
and control of squeezed quantum states.


title: Binomial Coefficients and the Distribution of the Primes

abstract:
  Let omega(n) be the number of distinct prime factors dividing n and m > n
natural numbers. We calculate a formula showing which prime numbers in which
intervals divide a given binomial coefficient. From this formula we get an
identity omega(binom(nk)(mk))=sum_i (pi(k/b(i))- pi(k/a(i))) + O(sqrt(k)).
Erdoes mentioned that omega(binom(nk)(mk))= log n^n/(m^m (n-m)^(n-m)) k/log k +
o(k/log k).
  As an application of the above identities, we conclude some well-known facts
about the distribution of the primes and deduce for all natural numbers k an
expression (also well-known) log k = sum_i a_k(i) which generalizes log 2 =
sum_i^(infty) (-1)^(j+1) / j.


title:
A continuation principle for a class of periodically perturbed
  autonomous systems

abstract:
  In this paper we evaluate the topological index of periodic solutions otained
via the Malkin-Loud bifurcation result. Incidentally, we do not assume that the
perturbation is differentiale.


title: The Dirichlet Markov Ensemble

abstract:
  We equip the polytope of $n\times n$ Markov matrices with the normalized
trace of the Lebesgue measure of $\mathbb{R}^{n^2}$. This probability space
provides random Markov matrices, with i.i.d. rows following the Dirichlet
distribution of mean $(1/n,...,1/n)$. We show that if $\bM$ is such a random
matrix, then the empirical distribution built from the singular values
of$\sqrt{n} \bM$ tends as $n\to\infty$ to a Wigner quarter--circle
distribution. Some computer simulations reveal striking asymptotic spectral
properties of such random matrices, still waiting for a rigorous mathematical
analysis. In particular, we believe that with probability one, the empirical
distribution of the complex spectrum of $\sqrt{n} \bM$ tends as $n\to\infty$ to
the uniform distribution on the unit disc of the complex plane, and that
moreover, the spectral gap of $\bM$ is of order $1-1/\sqrt{n}$ when $n$ is
large.


title:
Periodic bifurcation from families of periodic solutions for semilinear
  differential equations with Lipschitzian perturbations in Banach spaces

abstract:
  Let A:D(A)\to E be an infinitesimal generator either of an analytic compact
semigroup or of a contractive C_0-semigroup of linear operators acting in a
Banach space E. In this paper we give both necessary and sufficient conditions
for bifurcation of $T$-periodic solutions for the equation x'=Ax+f(t,x)+e
g(t,x,e) from a k-parameterized family of T-periodic solutions of the
unperturbed equation corresponding to e=0. We show that by means of a suitable
modification of the classical Mel'nikov approach we can construct a bifurcation
function and to formulate the conditions for the existence of bifurcation in
terms of the topological index of the bifurcation function. To do this, since
the perturbation term g is only Lipschitzian we need to extend the classical
Lyapunov-Schmidt reduction to the present nonsmooth case.


title: Parameter Tuning of Three-Flavor Dynamical Anisotropic Clover Action

abstract:
  In this work, we perform parameter tuning with dynamical anisotropic clover
lattices using the Schr\"odinger functional and stout-smearing in the fermion
field. We find that $\xi_R/\xi_0$ is relatively close to 1 in our parameter
search, which allows us to fix $\xi_0$ in our runs. We proposed to determine
the gauge and fermion anisotropy in a Schr\"odinger-background small box using
Wilson loop ratios and PCAC masses. We demonstrate that these ideas are
equivalent to but more efficient than the conventional meson dispersion
approach. The spatial and temporal clover coefficients are fixed to the
tree-level tadpole-improved clover values, and we demonstrate that they satisfy
the nonperturbative condition determined by Schr\"odinger functional method.


title: Regularity theory for fully nonlinear integro-differential equations

abstract:
  We consider nonlinear integro-differential equations, like the ones that
arise from stochastic control problems with purely jump L\`evy processes. We
obtain a nonlocal version of the ABP estimate, Harnack inequality, and interior
$C^{1,\alpha}$ regularity for general fully nonlinear integro-differential
equations. Our estimates remain uniform as the degree of the equation
approaches two, so they can be seen as a natural extension of the regularity
theory for elliptic partial differential equations.


title: Gravitational waves

abstract:
  These lectures are envisioned to be an introductory, basic course in
gravitational-wave physics.


title: Moduli Stabilization in Stringy ISS Models

abstract:
  We present a stringy realization of the ISS metastable SUSY breaking model
with moduli stabilization. The mass moduli of the ISS model is stabilized by
gauging of a U(1) symmetry and its D-term potential. The SUSY is broken both by
F-terms and D-terms. It is possible to obtain de-Sitter vacua with a
vanishingly small cosmological constant by an appropriate fine-tuning of flux
parameters.