title:
Distance, Growth Factor, and Dark Energy Constraints from Photometric
  Baryon Acoustic Oscillation and Weak Lensing Measurements

abstract:
  Baryon acoustic oscillations (BAOs) and weak lensing (WL) are complementary
probes of cosmology. We explore the distance and growth factor measurements
from photometric BAO and WL techniques and investigate the roles of the
distance and growth factor in constraining dark energy. We find for WL that the
growth factor has a great impact on dark energy constraints but is much less
powerful than the distance. Dark energy constraints from WL are concentrated in
considerably fewer distance eigenmodes than those from BAO, with the largest
contributions from modes that are sensitive to the absolute distance. Both
techniques have some well determined distance eigenmodes that are not very
sensitive to the dark energy equation of state parameters w_0 and w_a,
suggesting that they can accommodate additional parameters for dark energy and
for the control of systematic uncertainties. A joint analysis of BAO and WL is
far more powerful than either technique alone, and the resulting constraints on
the distance and growth factor will be useful for distinguishing dark energy
and modified gravity models. The Large Synoptic Survey Telescope (LSST) will
yield both WL and angular BAO over a sample of several billion galaxies. Joint
LSST BAO and WL can yield 0.5% level precision on ten comoving distances evenly
spaced in log(1+z) between redshift 0.3 and 3 with cosmic microwave background
priors from Planck. In addition, since the angular diameter distance, which
directly affects the observables, is linked to the comoving distance solely by
the curvature radius in the Friedmann-Robertson-Walker metric solution, LSST
can achieve a pure metric constraint of 0.017 on the mean curvature parameter
Omega_k of the universe simultaneously with the constraints on the comoving
distances.


title:
Magnetization Relaxation and Collective Spin Excitations in Correlated
  Double--Exchange Ferromagnets

abstract:
  We study spin relaxation and dynamics of collective spin excitations in
correlated double--exchange ferromagnets. For this, we introduce an expansion
of the Green's functions equations of motion that treats non--perturbativerly
all correlations between a given number of spin and charge excitations and
becomes exact within a sub--space of states. Our method treats relaxation
beyond Fermi's Golden Rule while recovering previous variational results for
the spin--wave dispersion. We find that the momentum dependence of the
spin--wave dephasing rate changes qualitatively due to the on--site Coulomb
interaction, in a way that resembles experiment, and depends on its interplay
with the magnetic exchange interaction and itinerant spin lifetime. We show
that the collective spin relaxation and its dependence on the carrier
concentration depends sensitively on three--body correlations between a spin
excitation and a Fermi sea electron and hole. The above spin dynamics can be
controlled via the itinerant carrier population.


title: On the factor set of code loops

abstract:
  A Code loop on a binary linear code that is doubly even with a factor set is
shown to be a central loop, conjugacy closed loop, Burn loop and extra loop.
General forms of the identities that define the factor set of a code are
deduced.


title:
Regulation of thermal conductivity in hot galaxy clusters by MHD
  turbulence

abstract:
  The role of thermal conduction in regulating the thermal behavior of cooling
flows in galaxy clusters is reexamined. Recent investigations have shown that
the anisotropic Coulomb heat flux caused by a magnetic field in a dilute plasma
drives a dynamical instability. A long standing problem of cooling flow theory
has been to understand how thermal conduction can offset radiative core losses
without completely preventing them. In this Letter we propose that
magnetohydrodynamic turbulence driven by the heat flux instability regulates
field-line insulation and drives a reverse convective thermal flux, both of
which may mediate the stabilization of the cooling cores of hot clusters. This
model suggests that turbulent mixing should accompany strong thermal gradients
in cooling flows. This prediction seems to be supported by the spatial
distribution of metals in the central galaxies of clusters, which shows a much
stronger correlation with the ambient hot gas temperature gradient than with
the parent stellar population.


title: Photon localization and Dicke superradiance in atomic gases

abstract:
  Photon propagation in a gas of N atoms is studied using an effective
Hamiltonian describing photon mediated atomic dipolar interactions. The density
P(\Gamma) of photon escape rates is determined from the spectrum of the N x N
random matrix \Gamma_{ij} = \sin (x_{ij}) / x_{ij}, where x_{ij} is the
dimensionless random distance between any two atoms. Varying disorder and
system size, a scaling behavior is observed for the escape rates. It is
explained using microscopic calculations and a stochastic model which
emphasizes the role of cooperative effects in photon localization and provides
an interesting relation with statistical properties of "small world networks".


title: Photon and polariton fluctuations in arrays of QED-cavities

abstract:
  We propose to detect the Mott insulator-superfluid quantum phase transition
in an array of coupled cavities by studying the polariton and photon
fluctuations in a block of linear dimension M (in units of the lattice constant
of the array). We explicitly show this for a one-dimensional array; the
analysis can be however extended to higher dimensions. In the Mott phase
polariton fluctuations are independent of the block size. In the superfluid
phase they grow logarithmically with M, the prefactor being related to the
compressibility of the system. In the case of photon fluctuations, the critical
behaviour is encoded in the subleading scaling with the block dimension, while
the leading behaviour is linear in M and non-critical. Our results have been
obtained by means of the density matrix renormalization group numerical
algorithm.


title:
Extraction of finite-energy contributions to the Sivers asymmetry from
  the analysis of exclusive proton-proton scattering

abstract:
  I study the effect of scalar and spin-orbit rescattering terms, in the
production of a nonzero Sivers-like asymmetry in proton-proton collisions
(nclusive production and Drell-Yan) at moderate center of mass energies
$\sqrt{s}$ $<$ 15 GeV and transverse momentum up to 3 GeV/c. An
ultrarelativistic generalization of the Glauber formalism is here used to (i)
fit the scalar and spin-orbit interaction terms on proton-proton elastic
scattering data, including analyzing power, (ii) transfer such information to
inclusive proton-proton scattering. It is shown that the phenomenological
interactions responsible for the nonzero analyzing power in proton-proton
elastic scattering produce a relevant nonzero analyzing power in inclusive
processes associated with proton-proton collisions. This could represent a
relevant (possibly higher-twist) contribution to the Sivers asymmetry.


title:
Cosmic-ray Monte Carlo predictions for forward particle production in
  p-p, p-Pb, and Pb-Pb collisions at the LHC

abstract:
  We present and compare the predictions of various cosmic-ray Monte Carlo
models for the energy (dE/deta) and particle (dN/deta) flows in p-p, p-Pb and
Pb-Pb collisions at sqrt(s) = 14, 8.8, and 5.5 TeV respectively, in the range
covered by forward LHC detectors like CASTOR or TOTEM (5.2<|eta|<6.6) and ZDC
or LHCf (|eta|>8.1 for neutrals).


title: Space-QUEST: Experiments with quantum entanglement in space

abstract:
  The European Space Agency (ESA) has supported a range of studies in the field
of quantum physics and quantum information science in space for several years,
and consequently we have submitted the mission proposal Space-QUEST (Quantum
Entanglement for Space Experiments) to the European Life and Physical Sciences
in Space Program. We propose to perform space-to-ground quantum communication
tests from the International Space Station (ISS). We present the proposed
experiments in space as well as the design of a space based quantum
communication payload.


title:
A scheme for fast exploratory simulation of azimuthal asymmetries in
  Drell-Yan experiments at intermediate energies. The DY_AB Monte Carlo event
  generator

abstract:
  In this note I report and discuss the physical scheme and the main
approximations used by the event generator code DY\_AB. This Monte Carlo code
is aimed at preliminary simulation, during the stage of apparatus planning, of
Drell-Yan events characterized by azimuthal asymmetries, in experiments with
moderate center of mass energy $\sqrt{s}$ $<<$ 100 GeV.


title:
Angular Pseudomomentum Theory for the Generalized Nonlinear
  Schr\"{o}dinger Equation in Discrete Rotational Symmetry Media

abstract:
  We develop a complete mathematical theory for the symmetrical solutions of
the generalized nonlinear Schr\"odinger equation based on the new concept of
angular pseudomomentum. We consider the symmetric solitons of a generalized
nonlinear Schr\"odinger equation with a nonlinearity depending on the modulus
of the field. We provide a rigorous proof of a set of mathematical results
justifying that these solitons can be classified according to the irreducible
representations of a discrete group. Then we extend this theory to
non-stationary solutions and study the relationship between angular momentum
and pseudomomentum. We illustrate these theoretical results with numerical
examples. Finally, we explore the possibilities of the generalization of the
previous framework to the quantum limit.


title: Thermally Assisted Spin Hall Effect

abstract:
  The spin polarized charge transport is systematically analyzed as a thermally
driven stochastic process. The approach is based on Kramers' equation
describing the semiclassical motion under the inclusion of stochastic and
damping forces. Due to the relativistic spin-orbit coupling the damping
experiences a relativistic correction leading to an additional contribution
within the spin Hall conductivity. A further contribution to the conductivity
is originated from the averaged underlying crystal potential, the mean value of
which depends significantly on the electric field. We derive an exact
expression for the electrical conductivity. All corrections are estimated in
lowest order of a relativistic approach and in the linear response regime.


title:
Quasiperiodic oscillations in Cen X-3 and the long term intensity
  variations

abstract:
  We have investigated properties of the Quasi Periodic Oscillation (QPO)
features in the accretion powered X-ray pulsar Cen X-3 over a period of about
four years using observations carried out with the Proportional Counter Array
(PCA) of the {\it {Rossi X-ray Timing Explorer}}. The observations cover a wide
range of X-ray intensity of the source in excess of the binary intensity
modulation. We have detected QPOs in 11 out of a total 81 pointings with the
PCA with rms intensity fluctuation upto 10%. The QPO peak frequency shows
clustering around 40 and 90 mHz with the QPO frequency having no dependence on
X-ray intensity. This indicates that either (a) the observed X-ray luminosity
of the source is not related to the mass accretion rate or inner radius of the
accretion disk or (b) that the QPO generation mechanism in Cen X-3 is different
from the beat frequency model or Keplerian frequency model that is believed to
be operational in most other transient and persistent X-ray pulsars. We have
also found that, the rms variation in the 40 mHz QPO feature is not dependent
on the X-ray energy, indicating that disk absorption related origin for the QPO
is unlikely.


title: Pseudo-Finslerian spacetimes and multi-refringence

abstract:
  It is reasonably well-known that birefringent crystal optics can to some
extent be described by the use of pseudo-Finslerian spacetimes (an extension of
pseudo-Riemannian spacetime). What is less commonly appreciated is that there
are two separate and quite disjoint pseudo-Finsler structures for the two
photon polarizations, and further, that there are separate tangent-space
pseudo-Finsler structures defined by the group velocity and co-tangent-space
pseudo-co-Finsler structures defined by the phase velocity. The
inter-connections between these four separate pseudo-Finsler structures are
rather subtle. One particular source of technical difficulty is the fact that
because physicists need to use pseudo-Finsler structures to describe
propagation of signals, there will be nonzero null vectors in both the tangent
and cotangent spaces -- this causes significant problems in that many of the
mathematical results normally obtained for "usual'' (Euclidean signature)
Finsler structures either do not apply, or require significant modifications to
their formulation. We shall first provide a few basic definitions, and then
present a tutorial outline of the relevant physics of birefringent optics,
explicitly demonstrating the interpretation in terms of pseudo-Finsler
spacetimes. We shall then discuss the tricky issues that arise when trying to
inter-relate the various pseudo-Finsler structures we encounter, and finish by
connecting these technical questions (which of course arise in what is a
physically a very well-understood situation) back to ongoing research into
possible extensions and modifications of general relativity.


title: Optimal Convergence Rates for Tikhonov Regularization in Besov Scales

abstract:
  In this paper we deal with linear inverse problems and convergence rates for
Tikhonov regularization. We consider regularization in a scale of Banach
spaces, namely the scale of Besov spaces. We show that regularization in Banach
scales differs from regularization in Hilbert scales in the sense that it is
possible that stronger source conditions may lead to weaker convergence rates
and vive versa. Moreover, we present optimal source conditions for
regularization in Besov scales.


title: Radiative neutrino mass generation and dark energy

abstract:
  We study the models with radiative neutrino mass generation and explore the
relation between the neutrino masses and dark energy. In these models, the
pseudo-Nambu-Goldston bosons (pNGBs) arise at two-loop level via the Majorana
neutrino masses. In particular, we demonstrate that the potential energy of the
pNGB can be the dark energy potential and the observed value of the equation of
state (EoS) parameter of the universe, $i.e.$, $w\simeq -1$, can be realized.


title:
The RMS Survey: $^{13}$CO observations of candidate massive YSOs in the
  northern Galactic plane

abstract:
  Context: The Red MSX Source (RMS) survey is an ongoing multi-wavelength
observational programme designed to return a large, high-resolution
mid-infrared colour-selected sample of massive young stellar objects.
  Aims: A critical part of our follow-up programme is to conduct 13CO molecular
line observations in order to determine kinematic distances to all of our MYSO
candidates. These distances will allow us to identify and remove nearby
low-mass YSOs and help in identifying evolved stars which are weak CO emitters.
  Method: We have used the 15 m James Clerk Maxwell Telescope (JCMT), the 13.7
m telescope of the Purple Mountain Observatory (PMO), the 20 m Onsala telescope
and the 22m Mopra telescope to conduct molecular line observations towards 508
MYSOs candidates located in the 1st and 2nd Quadrants.
  Results: We detect 13CO emission towards 780 RMS sources which corresponds to
approximately 84% of those observed (911). A total of 2595 emission components
are detected above 3sigma level (typically T^*_{\rm{A}} > 0.3K), with multiple
components being observed towards the majority of these sources -- 520 sources
(~56%) -- with an average of ~4 molecular clouds detected along each line of
sight. We have used archival CS (J=2-1) and maser velocities to resolve the
component multiplicity towards 175 sources (~20%) and have derived a criterion
which is used to identify the most likely component for a further 191 multiple
component sources. Combined with the single component detections we have
obtained unambiguous kinematic velocities for 638 of the 780 MYSOs candidates
towards which CO is detected (~80% of the detections). Using the Galactic
rotation curve we calculate kinematic distances for all detected components.


title:
Jet quenching and broadening: the transport coefficient $\hat{q}$ in an
  anisotropic plasma

abstract:
  The jet quenching parameter $\hat{q}$ is analyzed for a quark jet propagating
in an anisotropic plasma. The momentum anisotropy is calculated at high
temperature of the underlying quark-gluon plasma. $\hat{q}$ is explicitly
estimated in leading-logarithmic approximation by the broadening of the
massless quark interacting via gluon exchange. A plasma instability is present.
Strong indications are found that $\hat{q}$ is increasing with increasing
anisotropy. Possible implications for the saturation scale $Q_s$ in $A-A$
collisions are pointed out.


title:
Existence and symmetry of least energy solutions for a class of
  quasi-linear elliptic equations

abstract:
  For a general class of autonomous quasi-linear elliptic equations on R^n we
prove the existence of a least energy solution and show that all least energy
solutions do not change sign and are radially symmetric up to a translation in
R^n.


title:
A compact dual atom interferometer gyroscope based on laser-cooled
  rubidium

abstract:
  We present a compact and transportable inertial sensor for precision sensing
of rotations and accelerations. The sensor consists of a dual Mach-Zehnder-type
atom interferometer operated with laser-cooled $^{87}$Rb. Raman processes are
employed to coherently manipulate the matter waves. We describe and
characterize the experimental apparatus. A method for passing from a compact
geometry to an extended interferometer with three independent atom-light
interaction zones is proposed and investigated. The extended geometry will
enhance the sensitivity by more than two orders of magnitude which is necessary
to achieve sensitivities better than $10^{-8} $rad/s/$\sqrt{\rm Hz}$.


title: Finite-size errors in continuum quantum Monte Carlo calculations

abstract:
  We analyze the problem of eliminating finite-size errors from quantum Monte
Carlo (QMC) energy data. We demonstrate that both (i) adding a recently
proposed [S. Chiesa et al., Phys. Rev. Lett. 97, 076404 (2006)] finite-size
correction to the Ewald energy and (ii) using the model periodic Coulomb (MPC)
interaction [L. M. Fraser et al., Phys. Rev. B 53, 1814 (1996); P. R. C. Kent
et al., Phys. Rev. B 59, 1917 (1999); A. J. Williamson et al., Phys. Rev. B 55,
4851 (1997)] are good solutions to the problem of removing finite-size effects
from the interaction energy in cubic systems, provided the exchange-correlation
(XC) hole has converged with respect to system size. However, we find that the
MPC interaction distorts the XC hole in finite systems, implying that the Ewald
interaction should be used to generate the configuration distribution. The
finite-size correction of Chiesa et al. is shown to be incomplete in systems of
low symmetry. Beyond-leading-order corrections to the kinetic energy are found
to be necessary at intermediate and high densities, and we investigate the
effect of adding such corrections to QMC data for the homogeneous electron gas.
We analyze finite-size errors in two-dimensional systems and show that the
leading-order behavior differs from that which has hitherto been supposed. We
compare the efficiency of different twist-averaging methods for reducing
single-particle finite-size errors and we examine the performance of various
finite-size extrapolation formulas. Finally, we investigate the system-size
scaling of biases in diffusion QMC.


title:
Anomalous diffusion in heterogeneous glass-forming liquids:
  Temperature-dependent behavior

abstract:
  In a preceding paper, Mukhopadhyay and I studied the diffusive motion of a
tagged molecule in a heterogeneous glass-forming liquid at temperatures just
above a glass transition. Among other features of this system, we postulated a
relation between heterogeneity and stretched-exponential decay of correlations,
and we also confirmed that systems of this kind generally exhibit non-Gaussian
diffusion on intermediate length and time scales. Here I extend this analysis
to higher temperatures approaching the point where the heterogeneities
disappear and thermal activation barriers become small. I start by modifying
the continuous-time random-walk theory proposed earlier, and supplement this
analysis with an extension of the excitation-chain theory of glass dynamics. I
also use a key result from the shear-transformation-zone theory of viscous
deformation of amorphous materials. Elements of each of these theories are then
used to interpret experimental data for ortho-terphenyl, specifially, the
diffusion and viscosity coefficients and neutron scattering measurements of the
self intermediate scattering function. Reconciling the theory with these data
sets provides insights about the crossover between super-Arrhenius and
Arrhenius dynamics, length scales of spatial heterogeneities, violation of the
Stokes-Einstein relation in glass-forming liquids, and the origin of stretched
exponential decay of correlations.


title: Nuclear tetrahedral configurations at spin zero

abstract:
  The possibility of the existence of stable tetrahedral deformations at spin
zero is investigated using the Skyrme-HFBCS approach and the generator
coordinate method (GCM). The study is limited to nuclei in which the
tetrahedral mode has been predicted to be favored on the basis of non
self-consistent models. Our results indicate that a clear identification of
tetrahedral deformations is unlikely as they are strongly mixed with the axial
octupole mode. However, the excitation energies related to the tetrahedral mode
are systematically lower than those of the axial octupole mode in all the
nuclei included in this study.


title:
Energy transfer processes in Er-doped SiO2 sensitized with Si
  nanocrystals

abstract:
  We present a high-resolution photoluminescence study of Er-doped SiO2
sensitized with Si nanocrystals (Si NCs). Emission bands originating from
recombination of excitons confined in Si NCs and of internal transitions within
the 4f-electron core of Er3+ ions, and a band centered at lambda = 1200nm have
been identified. Their kinetics have been investigated in detail. Based on
these measurements, we present a comprehensive model for energy transfer
mechanisms responsible for light generation in this system. A unique picture of
energy flow between subsystems of Er3+ and Si NCs is developed, yielding truly
microscopic information on the sensitization effect and its limitations. In
particular, we show that most of the Er3+ ions available in the system are
participating in the energy exchange. The long standing problem of apparent
loss of optical activity of majority of Er dopants upon sensitization with Si
NCs is clarified and assigned to appearance of a very efficient energy exchange
mechanism between Si NCs and Er3+ ions. Application potential of SiO2:Er
sensitized by Si NCs is discussed in view of the newly acquired microscopic
insight.


title:
Location and phase segregation of ground and excited states for 2D
  Gross-Pitaevskii systems

abstract:
  We consider a system of Gross-Pitaevskii equations in R^2 modelling a mixture
of two Bose-Einstein condensates with repulsive interaction. We aim to study
the qualitative behaviour of ground and excited state solutions. We allow two
different harmonic and off-centered trapping potentials and study the spatial
patterns of the solutions within the Thomas-Fermi approximation as well as
phase segregation phenomena within the large-interaction regime.


title: X-ray time variability across the atoll source states of 4U 1636--53

abstract:
  We have studied the rapid X-ray time variability in 149 pointed observations
with the \textit{Rossi X-ray Timing Explorer} (RXTE)'s Proportional Counter
Array of the atoll source 4U~1636--53 in the banana state and, for the first
time with RXTE, in the island state. We compare the frequencies of the
variability components of 4U~1636--53 with those in other atoll and Z-sources
and find that 4U~1636--53 follows the universal scheme of correlations
previously found for other atoll sources at (sometimes much) lower
luminosities. Our results on the hectohertz QPO suggest that the mechanism that
sets its frequency differs from that for the other components, while the
amplitude setting mechanism is common. A previously proposed interpretation of
the narrow low-frequency QPO frequencies in different sources in terms of
harmonic mode switching is not supported by our data, nor by some previous data
on other sources and the frequency range that this QPO covers is found not to
be related to spin, angular momentum or luminosity.


title: Description of D-branes invariant under the Poisson-Lie T-plurality

abstract:
  We write the conditions for open strings with charged endpoints in the
language of gluing matrices. We identify constraints imposed on the gluing
matrices that are essential in this setup and investigate the question of their
invariance under the Poisson-Lie T-plurality transformations. We show that the
chosen set of constraints is equivalent to the statement that the lifts of
D-branes into the Drinfel'd double are right cosets with respect to a maximally
isotropic subgroup and therefore it is invariant under the Poisson-Lie
T-plurality transformations.


title:
Two-neutrino double beta decay of deformed nuclei within QRPA with
  realistic interaction

abstract:
  A method to implement realistic nucleon-nucleon residual interaction (Bonn CD
force) based on the Brueckner G-matrix into the Quasiparticle Random Phase
Approximation (QRPA) for deformed nuclei is formulated. The two-neutrino double
decay for ground state to ground state transitions $^{76}$Ge$ \to ^{76}$Se and
$^{150}$Nd $\to ^{150}$Sm is calculated along with the Gamow-Teller strength
distributions. The effect of deformation on the observables is studied.


title: Asymptotic behavior of a thermoviscoelastic plate with memory effects

abstract:
  We consider a coupled linear system describing a thermoviscoelastic plate
with hereditary effects. The system consists of a hyperbolic
integrodifferential equation, governing the temperature, which is linearly
coupled with the partial differential equation ruling the evolution of the
vertical deflection, presenting a convolution term accounting for memory
effects. It is also assumed that the thermal power contains a memory term
characterized by a relaxation kernel. We prove that the system is exponentially
stable and we obtain a closeness estimate between the system with memory
effects and the corresponding memory-free limiting system, as the kernels fade
in a suitable sense.


title:
The action of a nilpotent group on its horofunction boundary has finite
  orbits

abstract:
  We study the action of a nilpotent group G with finite generating set S on
its horofunction boundary. We show that there is one finite orbit associated to
each facet of the polytope obtained by projecting S into the infinite component
of the abelianisation of G. We also prove that these are the only finite orbits
of Busemann points. To finish off, we examine in detail the Heisenberg group
with its usual generators.


title:
Gravitation of finite range and the accelerated expansion of the
  universe

abstract:
  In an earlier work we showed that the gravitational interaction could be
reproduced as a retarded dispersion interaction (Casimir interaction) between
particles composed of hypothetical particles having harmonic oscillator
interactions. Here we derive the modification of the force when the vacuum
modes have a small but finite temperature. The resulting interaction is of
finite range. We give the result on analytical form.


title: Theory of spin current in chiral helimagnet

abstract:
  We give detailed description of the transport spin current in the chiral
helimagnet. Under the static magnetic field applied perpendicular to the
helical axis, the magnetic kink crystal (chiral soliton lattice) is formed.
Once the kink crystal begins to move under the Galilean boost, the spin-density
accumulation occurs inside each kink and there emerges periodic arrays of the
induced magnetic dipoles carrying the transport spin current. The coherent
motion of the kink crystal dynamically generates the spontaneous
demagnetization field. This mechanism is analogous to the
D\"{o}ring-Becker-Kittel mechanism of the domain wall motion in ferromagnets.
To describe the kink crystal motion, we took account of not only the tangential
$\phi$-fluctuations but the longitudinal $\theta$-fluctuations around the
helimagnetic configuration. Based on the collective coordinate method and the
Dirac's canonical formulation for the singular Lagrangian system, we derived
the closed formulae for the mass, spin current and induced magnetic dipole
moment accompanied with the kink crystal motion. To materialize the theoretical
model presented here, symmetry-adapted material synthesis would be required,
where the interplay of crystallographic and magnetic chirality plays a key role
there.


title: On the long term spatial segregation for a competition-diffusion system

abstract:
  We investigate the long term behavior for a class of competition-diffusion
systems of Lotka-Volterra type for two competing species in the case of low
regularity assumptions on the data. Due to the coupling that we consider the
system cannot be reduced to a single equation yielding uniform estimates with
respect to the inter-specific competition rate parameter. Moreover, in the
particular but meaningful case of initial data with disjoint support and
Dirichlet boundary data which are time-independent, we prove that as the
competition rate goes to infinity the solution converges, along with suitable
sequences, to a spatially segregated state satisfying some variational
inequalities.


title:
Systematic time-scale-bridging molecular dynamics applied to flowing
  polymer melts

abstract:
  We present a novel thermodynamically guided, low-noise, time-scale bridging,
and pertinently efficient strategy for the dynamic simulation of microscopic
models for complex fluids. The systematic coarse-graining method is exemplified
for low-molecular polymeric systems subjected to homogeneous flow fields. We
use established concepts of nonequilibrium thermodynamics and an alternating
Monte-Carlo--molecular dynamics iteration scheme in order to obtain the model
equations for the slow variables. For chosen flow situations of interest, the
established model predicts structural as well as material functions beyond the
regime of linear response. As a by-product, we present the first steady state
equibiaxial simulation results for polymer melts. The method is simple to
implement and allows for the calculation of time-dependent behavior through
quantities readily available from the nonequilibrium steady states.


title:
Flowing with Time: a New Approach to Nonlinear Cosmological
  Perturbations

abstract:
  Nonlinear effects are crucial in order to compute the cosmological matter
power spectrum to the accuracy required by future generation surveys. Here, a
new approach is presented, in which the power spectrum, the bispectrum and
higher order correlations, are obtained -- at any redshift and for any momentum
scale -- by integrating a system of differential equations. The method is
similar to the familiar BBGKY hierarchy. Truncating at the level of the
trispectrum, the solution of the equations corresponds to the summation of an
infinite class of perturbative corrections. Compared to other resummation
frameworks, the scheme discussed here is particularly suited to cosmologies
other than LambdaCDM, such as those based on modifications of gravity and those
containing massive neutrinos. As a first application, we compute the Baryonic
Acoustic Oscillation feature of the power spectrum, and compare the results
with perturbation theory, the halo model, and N-body simulations. The
density-velocity and velocity-velocity power spectra are also computed, showing
that they are much less contaminated by nonlinearities than the density-density
one. The approach can be seen as a particular formulation of the
renormalization group, in which time is the flow parameter.


title: Thermal photon dispersion law and modified black-body spectra

abstract:
  Based on the postulate that photon propagation is governed by an SU(2) gauge
principle we numerically compute the one-loop dispersion for thermalized photon
propagation on the radiatively induced mass shell. Formerly, the dispersion was
addressed by assuming $p^2=0$. While this approximation turns out to be
excellent for temperatures $\le 2 T_{\tiny{CMB}}$ the exact result exhibits a
much faster (power-like) shrinking of the gap in the black-body spectral
intensity with rising temperature. Our previous statements on anomalous
large-angle CMB temperature-temperature correlations, obtained in the
approximation $p^2=0$, remain valid.


title:
Some combinatorics related to central binomial coefficients: Grand-Dyck
  paths, coloured noncrossing partitions and signed pattern avoiding
  permutations

abstract:
  We give some interpretations to certain integer sequences in terms of
parameters on Grand-Dyck paths and coloured noncrossing partitions, and we find
some new bijections relating Grand-Dyck paths and signed pattern avoiding
permutations. Next we transfer a natural distributive lattice structure on
Grand-Dyck paths to coloured noncrossing partitions and signed pattern avoiding
permutations, thus showing, in particular, that it is isomorphic to the
structure induced by the (strong) Bruhat order on a certain set of signed
pattern avoiding permutations.


title:
Universality of citation distributions: towards an objective measure of
  scientific impact

abstract:
  We study the distributions of citations received by a single publication
within several disciplines, spanning broad areas of science. We show that the
probability that an article is cited $c$ times has large variations between
different disciplines, but all distributions are rescaled on a universal curve
when the relative indicator $c_f=c/c_0$ is considered, where $c_0$ is the
average number of citations per article for the discipline. In addition we show
that the same universal behavior occurs when citation distributions of articles
published in the same field, but in different years, are compared. These
findings provide a strong validation of $c_f$ as an unbiased indicator for
citation performance across disciplines and years. Based on this indicator, we
introduce a generalization of the h-index suitable for comparing scientists
working in different fields.

categories: physics.soc-ph cond-mat.stat-mech cs.DL physics.data-an


title: Tachyon Condensation on Torus and T-duality

abstract:
  We find an exact solution, with a nonzero net D-brane charge, in the boundary
string field theory of brane-anti-brane pairs on a torus. We explicitly take
the T-dual of this configuration. The Nahm-transformation of the instantons is
derived from the tachyon condensation.


title:
Low temperature synthesis and pressure induced insulator-metal
  transition of the newly found NdFeAsO0.75

abstract:
  As low as 900 oC, iron-based layered quaternary compound NdFeAsO0.75 was
synthesized through solid state reaction method. XRD measurements illustrate
almost pure phase of tetragonal phase NdFeAsO was formed. The synthesis
temperature in our experiment is the lowest among all the reported methods
without the help of any mineralizer. After further treatment under high
pressure of 6 GPa at temperature of 1300 oC for 2 hours, the electrical
transport property of NdFeAsO0.75 was transformed from insulator-like to metal-
like behavior.


title: Nonequilibrium dynamics in an amorphous solid

abstract:
  The non-equilibrium dynamics of an amorphous solid is studied with a
soft-spin type model. We show that the aging behavior in the glassy state
follows a modified Kohlrausch-Williams-Watts (KWW) form similar to that
obtained in Phys. Rev. Lett. {\bf 95}, 055702 (2005) from analysis of the
dielectric loss data. The nature of the fluctuation-dissipation theorem (FDT)
violation is also studied in the time as well as correlation windows.


title: Twisted exterior derivatives for universal enveloping algebras I

abstract:
  Consider any representation $\phi$ of a finite-dimensional Lie algebra $g$ by
derivations of the completed symmetric algebra $\hat{S}(g^*)$ of its dual.
Consider the tensor product of $\hat{S}(g^*)$ and the exterior algebra
$\Lambda(g)$. We show that the representation $\phi$ extends canonically to the
representation $\tilde\phi$ of that tensor product algebra. We construct an
exterior derivative on that algebra, giving rise to a twisted version of the
exterior differential calculus with the enveloping algebra in the role of the
coordinate algebra. In this twisted version, the commutators between the
noncommutative differentials and coordinates are formal power series in partial
derivatives. The square of the corresponding exterior derivative is zero like
in the classical case, but the Leibniz rule is deformed.


title: Pruning the Tree of Life: k-core Percolation as Selection Mechanism

abstract:
  We propose a model for evolution aiming to reproduce statistical features of
fossil data, in particular the distributions of extinction events, the
distribution of species per genus and the distribution of lifetimes, all of
which are known to be of power law type. The model incorporates both
species-species interactions and ancestral relationships. The main novelty of
this work is to show the feasibility of k-core percolation as a selection
mechanism. We give theoretical predictions for the observable distributions,
confirm their validity by computer simulation and report good agreement with
the fossil data. A key feature of the proposed model is a co-evolving fitness
landscape determined by the topology of the underlying species interactions,
ecological niches emerge naturally. The predicted distributions are independent
of the rate of speciation, i.e. whether one adopts an gradualist or punctuated
view of evolution.


title:
Magnetization Relaxation and Collective Vortex Pinning in the Fe-Based
  Superconductor SmFeAsO_0.9F_0.1

abstract:
  By measuring the dynamic and traditional magnetization relaxations we
investigate the vortex dynamics of the newly discovered superconductor
SmFeAsO_0.9F_0.1 with Tc = 55K. It is found that the relaxation rate is rather
large reflecting a small characteristic pinning energy. Moreover it shows a
weak temperature dependence in wide temperature region, which resembles the
behavior of the cuprate superconductors. Combining with the resistive data
under different magnetic fields, a vortex phase diagram is obtained. Our
results strongly suggest that the model of collective vortex pinning applies to
this new superconductor very well.


title: Holographic Cosmological Models on the Braneworld

abstract:
  In this article we have studied a closed universe which a holographic energy
on the brane whose energy density is described by $\rho (H) =3c^{2}H^{2}$ and
we obtain an equation for the Hubble parameter, this equation gave us different
physical behavior depending if $c^2>1$ or $c^2<1$ against of the sign of the
brane tension.


title: Generalized parity measurements

abstract:
  Measurements play an important role in quantum computing (QC), by either
providing the nonlinearity required for two-qubit gates (linear optics QC), or
by implementing a quantum algorithm using single-qubit measurements on a highly
entangled initial state (cluster state QC). Parity measurements can be used as
building blocks for preparing arbitrary stabilizer states, and, together with
1-qubit gates are universal for quantum computing. Here we generalize parity
gates by using a higher dimensional (qudit) ancilla. This enables us to go
beyond the stabilizer/graph state formalism and prepare other types of
multi-particle entangled states. The generalized parity module introduced here
can prepare in one-shot, heralded by the outcome of the ancilla, a large class
of entangled states, including GHZ_n, W_n, Dicke states D_{n,k}, and, more
generally, certain sums of Dicke states, like G_n states used in secret
sharing. For W_n states it provides an exponential gain compared to linear
optics based methods.


title: A Comparison of Performance Measures for Online Algorithms

abstract:
  This paper provides a systematic study of several proposed measures for
online algorithms in the context of a specific problem, namely, the two server
problem on three colinear points. Even though the problem is simple, it
encapsulates a core challenge in online algorithms which is to balance
greediness and adaptability. We examine Competitive Analysis, the Max/Max
Ratio, the Random Order Ratio, Bijective Analysis and Relative Worst Order
Analysis, and determine how these measures compare the Greedy Algorithm, Double
Coverage, and Lazy Double Coverage, commonly studied algorithms in the context
of server problems. We find that by the Max/Max Ratio and Bijective Analysis,
Greedy is the best of the three algorithms. Under the other measures, Double
Coverage and Lazy Double Coverage are better, though Relative Worst Order
Analysis indicates that Greedy is sometimes better. Only Bijective Analysis and
Relative Worst Order Analysis indicate that Lazy Double Coverage is better than
Double Coverage. Our results also provide the first proof of optimality of an
algorithm under Relative Worst Order Analysis.


title:
Supersequences, rearrangements of sequences, and the spectrum of bases
  in additive number theory

abstract:
  The set A = {a_n} of nonnegative integers is an asymptotic basis of order h
if every sufficiently large integer can be represented as the sum of h elements
of A. If a_n ~ alpha n^h for some real number alpha > 0, then alpha is called
an additive eigenvalue of order h. The additive spectrum of order h is the set
N(h) consisting of all additive eigenvalues of order h. It is proved that there
is a positive number eta_h <= 1/h! such that N(h) = (0, eta_h) or N(h) = (0,
eta_h]. The proof uses results about the construction of supersequences of
sequences with prescribed asymptotic growth, and also about the asymptotics of
rearrangements of infinite sequences. For example, it is proved that there does
not exist a strictly increasing sequence of integers B = {b_n} such that b_n ~
2^n and B contains a subsequence {b_{n_k}} such that b_{n_k} ~ 3^k.


title: Revisiting Zitterbewegung

abstract:
  The Dirac wave equation for the electron soon lead to the recognition of the
Zitterbewegung. This was studied both by Schrodinger and Dirac. Later there
were further elegant and sometimes dissenting insights, from different authors.
We briefly review some of these developments. However in more recent times with
dark energy and noncommutative spacetime coming to centre stage, the earlier
studies of Zitterbewegung become questionable.


title: Remarks On A Nicolas Inequality

abstract:
  This submission has been withdrawn by arXiv admins because it contains
inappropriate, fictitious text in the acknowledgments and the final reference.


title:
Decoherence, Entanglement and Irreversibility in Quantum Dynamical
  Systems with Few Degrees of Freedom

abstract:
  This review summarizes and amplifies on recent investigations of coupled
quantum dynamical systems in the short wavelength limit. We formulate and
attempt to answer three fundamental questions: (i) What drives a dynamical
quantum system to behave classically ? (ii) What determines the rate at which
two coupled quantum--mechanical systems become entangled ? (iii) How does
irreversibility occur in quantum systems with few degrees of freedom ? We embed
these three questions in the broader context of the quantum--classical
correspondence, which motivates the use of short--wavelength approximations to
quantum mechanics such as the trajectory-based semiclassical methods and random
matrix theory. Doing so, we propose a novel investigative procedure towards
decoherence and the emergence of classicality out of quantumness in dynamical
systems coupled to external degrees of freedom. We reproduce known results
derived using master equation or Lindblad approaches but also generate novel
ones. In particular we show how local exponential instability also affects the
temporal evolution of quantum chaotic dynamical systems. We extensively rely on
numerical experiments to illustrate our findings and briefly comment on
possible extensions to more complex problems involving environments with $n \gg
1$ interacting dynamical systems, going beyond the uncoupled harmonic
oscillator model of Caldeira and Leggett.


title:
Very High Energy Gamma-Ray Observations of a Strong Flaring Activity in
  M87 in 2008 February

abstract:
  M87 is the only known non blazar radio galaxy to emit very high energy (VHE)
gamma-rays. During a monitoring program of M87, a rapid flare in VHE gamma-rays
was detected by the MAGIC telescope in early 2008. The flux was found to be
variable above 350 GeV on a timescale as short as 1 day at a significance level
of $5.6\sigma$. The highest measured flux reached 15% of the Crab Nebula flux.
We observed several substantial changes of the flux level during the 13 day
observing period. The flux at lower energies (150 -- 350 GeV), instead, is
compatible with being constant. The energy spectrum can be described by a power
law with a photon index of $2.30 \pm 0.11_\mathrm{stat} \pm
0.20_\mathrm{syst}$. The observed day-scale flux variability at VHE prefers the
M87 core as source of the emission and implies that either the emission region
is very compact (just a few Schwarzschild radii) or the Doppler factor of the
emitting blob is rather large in the case of a non expanding emission region.


title:
Independent Measurement of the Total Active 8B Solar Neutrino Flux Using
  an Array of 3He Proportional Counters at the Sudbury Neutrino Observatory

abstract:
  The Sudbury Neutrino Observatory (SNO) used an array of 3He proportional
counters to measure the rate of neutral-current interactions in heavy water and
precisely determined the total active (nu_x) 8B solar neutrino flux. This
technique is independent of previous methods employed by SNO. The total flux is
found to be 5.54(+0.33/-0.31 stat, +0.36/-0.34 syst) x 10^6 cm^-2 s^-1, in
agreement with previous measurements and standard solar models. A global
analysis of solar and reactor neutrino results yields Delta m^2 =
7.59(+0.19/-0.21) x 10^-5 eV^2 and theta = 34.4(+1.3/-1.2) degrees. The
uncertainty on the mixing angle has been reduced from SNO's previous results.


title: Excitations of attractive 1-D bosons: Binding vs. fermionization

abstract:
  The stationary states of few bosons in a one-dimensional harmonic trap are
investigated throughout the crossover from weak to strongly attractive
interactions. For sufficient attraction, three different classes of states
emerge: (i) N-body bound states, (ii) bound states of smaller fragments, and
(iii) gas-like states that fermionize, that is, map to ideal fermions in the
limit of infinite attraction. The two-body correlations and momentum spectra
characteristic of the three classes are discussed, and the results are
illustrated using the soluble two-particle model.


title: Trivial centralizers for codimension-one attractors

abstract:
  We show that if $\Lambda$ is a codimension-one hyperbolic attractor for a
$C^r$ diffeomorphism $f$, where $2\leq r\leq \infty$, and $f$ is not Anosov,
then there is a neighborhood $\mathcal{U}$ of $f$ in $\mathrm{Diff}^r(M)$ and
an open and dense set $\mathcal{V}$ of $\mathcal{U}$ such that any
$g\in\mathcal{V}$ has a trivial centralizer on the basin of attraction for
$\Lambda$.


title:
Dissipative dynamics of a two - level system resonantly coupled to a
  harmonic mode

abstract:
  We propose an approximation scheme to describe the dynamics of the spin-boson
model when the spectral density of the environment shows a peak at a
characteristic frequency $\Omega$ which can be very close (or even equal) to
the spin Zeeman frequency $\Delta$. Mapping the problem onto a two-state system
(TSS) coupled to a harmonic oscillator (HO) with frequency $\omega_0$ we show
that the representation of displaced HO states provides an appropriate basis to
truncate the Hilbert space of the TSS-HO system and therefore a better picture
of the system dynamics. We derive an effective Hamiltonian for the TSS-HO
system, and show it furnishes a very good approximation for the system dynamics
even when its two subsystems are moderately coupled. Finally, assuming the
regime of weak HO-bath coupling and low temperatures, we are able to
analytically evaluate the dissipative TSS dynamics.


title: The stochastic Hamilton-Jacobi equation

abstract:
  We extend some aspects of the Hamilton-Jacobi theory to the category of
stochastic Hamiltonian dynamical systems. More specifically, we show that the
stochastic action satisfies the Hamilton-Jacobi equation when, as in the
classical situation, it is written as a function of the configuration space
using a regular Lagrangian submanifold. Additionally, we will use a variation
of the Hamilton-Jacobi equation to characterize the generating functions of
one-parameter groups of symplectomorphisms that allow to rewrite a given
stochastic Hamiltonian system in a form whose solutions are very easy to find;
this result recovers in the stochastic context the classical solution method by
reduction to the equilibrium of a Hamiltonian system.


title:
Strongly localized quantum crystalline states and behavior of the dilute
  jellium model

abstract:
  We name strongly localized quantum crystalline state (SLQCS) a determinantal
wave-function of the single-particle wave-functions obtained by crystalline
translations of a wave-function different from zero only within a primitive
cell of the considered quantum crystalline phase. SLQCSs accurately reproduce
the low density behaviour of the quantum crystals that, as Wigner's crystalline
phase of the jellium model, can become very dilute. Our analysis explicitly
deals with this system. We show that the SLQCS energy per particle at large
dilution ($r_s$) behaves as $-M_{dl,\sigma}/r_s+C_{\sigma}/{r_s}^{3/2}$, where
$M_{dl,\sigma}$ turns out to be the Madelung constant of the considered cubic
symmetry $\sigma$ and $C_{\sigma}$ is a positive constant only numerically
determined. Moreover, as the density gets smaller and smaller, each electron
becomes more and more confined to the centre of its cell.


title: Searching for Higgs Decaying to H->WW->mu + tau and H->WW->ee at DO

abstract:
  A search for the Higgs boson in H->WW->ee and H->WW->mu+tau decays in ppbar
collisions at a center-of-mass energy of sqrt(s)=1.96 TeV is presented. The
data have been collected by the Run II DO detector. In order to maximize the
sensitivity multivariate techniques such as artificial neural networks (NN),
matrix element methods and likelihoods are used. No excess above the Standard
Model background is observed and limits on the production cross section times
branching ratio for Higgs masses between 115 and 200 GeV are set.


title:
Spontaneous periodic travelling waves in oscillatory systems with
  cross-diffusion

abstract:
  We identify a new type of pattern formation in spatially distributed active
systems. We simulate one-dimensional two-component systems with predator-prey
local interaction and pursuit-evasion taxis between the components. In a
sufficiently large domain, spatially uniform oscillations in such systems are
unstable with respect to small perturbations. This instability, through a
transient regime appearing as spontanous focal sources, leads to establishment
of periodic traveling waves. The traveling waves regime is established even if
boundary conditions do not favor such solutions. The stable wavelength are
within a range bounded both from above and from below, and this range does not
coincide with instability bands of the spatially uniform oscillations.


title: Short-range nucleon correlations and neutrino emission by neutron stars

abstract:
  We argue that significant probability of protons with momenta above their
Fermi surface leads for proton concentrations p/n > 1/8 to the enhancement of
termally excited direct and modified URCA processes within a cold neutron star,
and to a nonzero probability of direct URCA processes for small proton
concentrations (p/n < 1/8). We evaluate high momentum tails of neutron, proton
and electrons distributions within a neutron star. We expect also significantly
faster neutrino cooling of hyperon stars.


title: The signal of $Z^\pm(4430)$ in nucleon-antinucleon scattering

abstract:
  We study the production of $Z^\pm(4430)$ at a nucleon-antinucleon scattering
experiment. Considering the PANDA experiment to be an ideal platform to explore
the production of the charmonium and charmonim-like states, we suggest the
forthcoming PANDA experiment to pay attention to the production of
$Z^\pm(4430)$.


title: The gauge theory of dislocations: conservation and balance laws

abstract:
  We derive conservation and balance laws for the translational gauge theory of
dislocations by applying Noether's theorem. We present an improved
translational gauge theory of dislocations including the dislocation density
tensor and the dislocation current tensor. The invariance of the variational
principle under the continuous group of transformations is studied. Through
Lie's-infinitesimal invariance criterion we obtain conserved translational and
rotational currents for the total Lagrangian made up of an elastic and
dislocation part. We calculate the broken scaling current. Looking only on one
part of the whole system, the conservation laws are changed into balance laws.
Because of the lack of translational, rotational and dilatation invariance for
each part, a configurational force, moment and power appears. The corresponding
J, L and M integrals are obtained. Only isotropic and homogeneous materials are
considered and we restrict ourselves to a linear theory. We choose constitutive
laws for the most general linear form of material isotropy. Also we give the
conservation and balance laws corresponding to the gauge symmetry and the
addition of solutions. From the addition of solutions we derive a reciprocity
theorem for the gauge theory of dislocations. Also, we derive the conservation
laws for stress-free states of dislocations.


title: Ueber die Geometrie der alten Aegypter

abstract:
  Lecture given before the Royal Academy Vienna that summarizes the state of
knowledge about the mathematics of the ancient Egyptians, up to 1884. Contains
all relevant references to classical Greek texts, and the 'latest' archeology
results. Later published as booklet. A list with completed bibliographic
references is appended.
  -----
  Vortrag vor der k.u.k. Akademie der Wissenschaften in Wien, 1884, ueber den
damaligen Wissensstand zur Mathematik der Aegypter, mit Referenzen zu den
klassischen griechischen Texten und damalige 'neue' Erkenntnisse der
Archaeologie. Spaeter als Heftchen gedruckt. Hinzugefiegt wurden komplette
bibliografische Referenzen fuer diejenigen, die im Text unvollstaendig
angegeben wurden.


title: Does Ten Have a Friend?

abstract:
  Any positive integer $n$ other than 10 with abundancy index 9/5 must be a
square with at least 6 distinct prime factors, the smallest being 5. Further,
at least one of the prime factors must be congruent to 1 modulo 3 and appear
with an exponent congruent to 2 modulo 6 in the prime power factorization of
$n$.


title: A transient radio jet in an erupting dwarf nova

abstract:
  Astrophysical jets seem to occur in nearly all types of accreting objects:
from supermassive black holes to young stellar objects. Based on X-ray
binaries, a unified scenario describing the disc/jet coupling has evolved and
extended to many accreting objects. The only major exceptions are thought to be
cataclysmic variables: Dwarf novae, weakly accreting white dwarfs, show similar
outburst behaviour as X-ray binaries but no jet has yet been detected. Here we
present radio observations of a dwarf nova in outburst showing variable
flat-spectrum radio emission that is best explained as synchrotron emission
originating in a transient jet. Both the inferred jet power and the relation to
the outburst cycle are analogous to those seen in X-ray binaries, suggesting
that the disc/jet coupling mechanism is ubiquitous.


title:
Correlation Between Phase Competition and the Nucleation of a Griffiths
  Phase in (La1-yPry)0.7Ca0.3Mn16/18O3

abstract:
  Detailed analyses of the temperature-dependent zero field ac susceptibility
of prototypical phase-separated (La1-yPry)0.7Ca0.3Mn16/18O3, 0 < y < 1, reveal
features consistent with the presence of a Griffiths phase (GP), viz., an
inverse susceptibility characterized by power law with 0.05 < lamda < 0.33 as y
decreases towards yc < 0.85. Beyond yc = 0.85, the GP is suppressed. These
data, combined with previous neutron diffraction measurements, enable a phase
diagram summarizing the evolution of the GP with composition to be constructed
for this system; in particular, it shows that the disorder relevant for the
establishment of such a phase is linked closely to the relative volume
fractions of the phase separated antiferromagnetic and ferromagnetic
components, even when the recently estimated double exchange (DE) linked
percolation threshold is exceeded. The influence of electron-phonon coupling
can also be seen through oxygen isotope effects.


title: Analytic structure of many-body Coulombic wave functions

abstract:
  We investigate the analytic structure of solutions of non-relativistic
Schr"odinger equations describing Coulombic many-particle systems. We prove the
following: Let psi(x) with x=(x_1,...,x_N) in R^{3N} denote an N-electron
wavefunction of such a system with one nucleus fixed at the origin. Then in a
neighbourhood of a coalescence point, for which x_1=0 and the other electron
coordinates do not coincide, and differ from 0, psi can be represented locally
as psi(x) = psi^(1)(x) + |x_1|psi^(2)(x) with psi^(1), psi^(2) real analytic. A
similar representation holds near two-electron coalescence points. The
Kustaanheimo-Stiefel transform and analytic hypoellipticity play an essential
role in the proof.


title:
Viscous damping of r-mode oscillations in compact stars with quark
  matter

abstract:
  We determine characteristic timescales for the viscous damping of r-mode
oscillations in rapidly rotating compact stars that contain quark matter. We
present results for the color-flavor-locked (CFL) phase of dense quark matter,
in which the up, down and strange quarks are gapped, as well as the normal
(ungapped) quark phase. While the ungapped quark phase supports a temperature
window between 10^8 K and 5x10^9 K where the r-mode is damped even for rapid
rotation, the r-mode in a rapidly rotating pure CFL star is not damped in the
temperature range 10^10 K - 10^11 K. Rotating hybrid stars with quark matter
cores display an instability window whose width is determined by the amount of
quark matter present, and they can have large spin frequencies outside this
window. Except at high temperatures T > 10^10 K, the presence of a quark phase
allows for larger critical frequencies and smaller spin-periods compared to
rotating neutron stars. If low-mass X-ray binaries contain a large amount of
ungapped or CFL quark matter, then our estimates of the r-mode instability
suggest that there should be a population of rapidly rotating binaries at
frequencies greater than 1000 Hz which have not yet been observed.


title: The VO-Neural project: recent developments and some applications

abstract:
  VO-Neural is the natural evolution of the Astroneural project which was
started in 1994 with the aim to implement a suite of neural tools for data
mining in astronomical massive data sets. At a difference with its ancestor,
which was implemented under Matlab, VO-Neural is written in C++, object
oriented, and it is specifically tailored to work in distributed computing
architectures. We discuss the current status of implementation of VO-Neural,
present an application to the classification of Active Galactic Nuclei, and
outline the ongoing work to improve the functionalities of the package.


title:
Competition between Discrete Random Variables, with Applications to
  Occupancy Problems

abstract:
  Consider $n$ players whose "scores" are independent and identically
distributed values $\{X_i\}_{i=1}^n$ from some discrete distribution $F$. We
pay special attention to the cases where (i) $F$ is geometric with parameter
$p\to0$ and (ii) $F$ is uniform on $\{1,2,...,N\}$; the latter case clearly
corresponds to the classical occupancy problem. The quantities of interest to
us are, first, the $U$-statistic $W$ which counts the number of "ties" between
pairs $i,j$; second, the univariate statistic $Y_r$, which counts the number of
strict $r$-way ties between contestants, i.e., episodes of the form
${X_i}_1={X_i}_2=...={X_i}_r$; $X_j\ne {X_i}_1;j\ne i_1,i_2,...,i_r$; and, last
but not least, the multivariate vector $Z_{AB}=(Y_A,Y_{A+1},...,Y_B)$. We
provide Poisson approximations for the distributions of $W$, $Y_r$ and $Z_{AB}$
under some general conditions. New results on the joint distribution of cell
counts in the occupancy problem are derived as a corollary.


title:
Rigidity at the boundary for conformal structures and other Cartan
  geometries

abstract:
  In this paper, we consider the problem of building a conformal boundary,
embedding a pseudo-Riamnnian manifold as an open subset of a bigger one. We get
first results about conformal maximality. We also show that in dimension $\geq
3$, there are rigidity properties for the topological boundary of such a
conformal embedding. We get results of the same kind about general Cartan
geometries.


title: PPM-Extended (PPMX) - a catalogue of positions and proper motions

abstract:
  Aims: We build a catalogue PPM-Extended (PPMX) on the ICRS system which is
complete down to a well-defined limiting magnitude and contains the best
presently available proper motions to be suited for kinematical studies in the
Galaxy.
  Methods: We perform a rigorous weighted least-squares adjustment of
individual observations, spread over more than a century, to determine mean
positions and proper motions. The stellar content of PPMX is taken from GSC 1.2
supplemented by catalogues like ARIHIP, PPM and Tycho-2 at the bright end. All
observations have been weighted according to their individual accuracy. The
catalogue has been screened towards rejecting false entries in the various
source catalogues.
  Results: PPM-Extended (PPMX) is a catalogue of 18,088,920 stars containing
astrometric and photometric information. Its limiting magnitude is about 15.2
in the GSC photometric system. PPMX consists of three parts: a) a survey
complete down to R_U = 12.8 in the magnitude system of UCAC2; b) additional
stars of high-precision proper motions, and c) all other stars from GSC 1.2
identified in 2MASS. The typical accuracy of the proper motions is 2mas/y for
66 percent of the survey stars (a) and the high-precision stars (b), and about
10 mas/y for all other stars. PPMX contains photometric information from
ASCC-2.5 and 2MASS.


title: The Fractional Langevin Equation: Brownian Motion Revisited

abstract:
  We have revisited the Brownian motion on the basis of the fractional Langevin
equation which turns out to be a particular case of the generalized Langevin
equation introduced by Kubo on 1966. The importance of our approach is to model
the Brownian motion more realistically than the usual one based on the
classical Langevin equation, in that it takes into account also the retarding
effects due to hydrodynamic backflow, i.e. the added mass and the Basset memory
drag. On the basis of the two fluctuation-dissipation theorems and of the
techniques of the Fractional Calculus we have provided the analytical
expressions of the correlation functions (both for the random force and the
particle velocity) and of the mean squared particle displacement. The random
force has been shown to be represented by a superposition of the usual white
noise with a "fractional" noise. The velocity correlation function is no longer
expressed by a simple exponential but exhibits a slower decay, proportional to
$t^{-3/2}$ as $t \to \infty$, which indeed is more realistic. Finally, the mean
squared displacement has been shown to maintain, for sufficiently long times,
the linear behaviour which is typical of normal diffusion, with the same
diffusion coefficient of the classical case. However, the Basset history force
induces a retarding effect in the establishing of the linear behaviour, which
in some cases could appear as a manifestation of anomalous diffusion to be
correctly interpreted in experimental measurements.

categories: math-ph cond-mat.stat-mech math.MP math.PR


title:
Quantum trigonometric Calogero-Sutherland model and irreducible
  characters for the exceptional algebra E8

abstract:
  We express the Hamiltonian of the quantum trigonometric Calogero-Sutherland
model for the Lie algebra E8 and coupling constant k=1 by using the fundamental
irreducible characters of the algebra as dynamical independent variables. Then,
we compute the second order characters of the algebra and some higher order
characters.


title:
Negative Entropy, Zero temperature and stationary Markov Chains on the
  interval

abstract:
  We analyze some properties of maximizing stationary Markov probabilities on
the Bernoulli space $[0,1]^\mathbb{N}$, More precisely, we consider ergodic
optimization for a continuous potential $A$, where $A: [0,1]^\mathbb{N}\to
\mathbb{R}$ which depends only on the two first coordinates. We are interested
in finding stationary Markov probabilities $\mu_\infty$ on $ [0,1]^\mathbb{N}$
that maximize the value $ \int A d \mu,$ among all stationary Markov
probabilities $\mu$ on $[0,1]^\mathbb{N}$. This problem correspond in
Statistical Mechanics to the zero temperature case for the interaction
described by the potential $A$. The main purpose of this paper is to show,
under the hypothesis of uniqueness of the maximizing probability, a Large
Deviation Principle for a family of absolutely continuous Markov probabilities
$\mu_\beta$ which weakly converges to $\mu_\infty$. The probabilities
$\mu_\beta$ are obtained via an information we get from a Perron operator and
they satisfy a variational principle similar to the pressure. Under the
hypothesis of $A$ being $C^2$ and the twist condition, that is,
$\frac{\partial^2 A}{\partial_x \partial_y} (x,y) \neq 0$, for all $(x,y) \in
[0,1]^2$, we show the graph property.


title: Heavy flavor in heavy-ion collisions at RHIC and RHIC II

abstract:
  In the initial years of operation, experiments at the Relativistic Heavy Ion
Collider (RHIC) have identified a new form of matter formed in nuclei-nuclei
collisions at energy densities more than 100 times that of a cold atomic
nucleus. Measurements and comparison with relativistic hydrodynamic models
indicate that the matter thermalizes in an unexpectedly short time, has an
energy density at least 15 times larger than needed for color deconfinement,
has a temperature about twice the critical temperature predicted by lattice
QCD, and appears to exhibit collective motion with ideal hydrodynamic
properties - a "perfect liquid" that appears to flow with a near-zero viscosity
to entropy ratio - lower than any previously observed fluid and perhaps close
to a universal lower bound. However, a fundamental understanding of the medium
seen in heavy-ion collisions at RHIC does not yet exist. The most important
scientific challenge for the field in the next decade is the quantitative
exploration of the new state of nuclear matter. That will require new data that
will, in turn, require enhanced capabilities of the RHIC detectors and
accelerator. In this report we discuss the scientific opportunities for an
upgraded RHIC facility - RHIC II - in conjunction with improved capabilities of
the two large RHIC detectors, PHENIX and STAR. We focus solely on heavy flavor
probes. Their production rates are calculable using the well-established
techniques of perturbative QCD and their sizable interactions with the hot QCD
medium provide unique and sensitive measurements of its crucial properties
making them one of the key diagnostic tools available to us.


title: Magnetic fields in star-forming galaxies at high and low redshift

abstract:
  As part of an ongoing series of deep GMRT surveys we have observed the
Spitzer extragalactic First Look Survey field, producing the deepest wide-field
610-MHz survey published to date. We reach an rms noise of 30 microJy/beam
before primary beam correction, with a resolution of ~6 arcsec over an area of
~4 square degrees. By combining these observations with the existing 1.4-GHz
VLA survey produced by Condon et al. (2003), along with infrared data in up to
seven wavebands from the Spitzer Space Telescope, optical photometry from SDSS
and a range of spectroscopic redshift surveys, we are able to study the
relationship between radio luminosity and star formation rate in star-forming
galaxies up to z ~ 1. The large amount of multi-wavelength data available
allows accurate k-corrections to be performed in the radio due to the knowledge
of the radio spectral index, and in the infrared through the use of a
semi-empirical radiative transfer model which models star-forming regions, warm
dust surrounding these regions, and diffuse interstellar dust, taking into
account the star formation rate, star formation history and hydrogen column
density within each galaxy. A strong correlation is seen between radio
luminosity and infrared-derived star formation rates, which is best fit by a
slightly non-linear power-law. We look for cosmic evolution in the comparative
radio brightness of star-forming galaxies by searching for deviations away from
the global relationship. Any such deviation would indicate a systematic
variation in one or more of the properties controlling synchrotron radiation,
in particular an increase in the magnetic field strengths of star-forming
galaxies. The data shows no evidence for such an effect, suggesting that there
has been little evolution in the magnetic fields of galaxies since z ~ 1.


title: Hyperbolic Groups Which Fiber in Infinitely Many Ways

abstract:
  We construct examples of free-by-cyclic hyperbolic groups which fiber in
infinitely many ways over Z. The construction involves adding a specialized
square 2-cell to a non-positively curved, squared 2-complex defined by labeled
oriented graphs. The fundamental groups of the resulting complexes are
hyperbolic, free-by-cyclic and can be mapped onto Z in infinitely many ways.


title:
Action approach to cosmological perturbations: the 2nd order metric in
  matter dominance

abstract:
  We study nonlinear cosmological perturbations during the post-inflationary
evolution, using the equivalence between a perfect barotropic fluid and a
derivatively coupled scalar field with Lagrangian [-(\partial
\phi)^2]^[(1+w)/2w]. Since this Lagrangian is just a special case of
k-inflation, this approach is analogous to the one employed in the study of
non-Gaussianities from inflation. We use this method to derive the second order
metric during matter dominance in the comoving gauge directly as function of
the primordial inflationary perturbation \zeta. Going to Poisson gauge, we
recover the metric previously derived in the literature.


title: Gorenstein rings through face rings of manifolds

abstract:
  The face ring of a homology manifold (without boundary) modulo a generic
system of parameters is studied. Its socle is computed and it is verified that
a particular quotient of this ring is Gorenstein. This fact is used to prove
that the sphere $g$-conjecture implies all enumerative consequences of its far
reaching generalization (due to Kalai) to manifolds. A special case of Kalai's
manifold $g$-conjecture is established for homology manifolds that have a
codimension-two face whose link contains many vertices.


title: Hamiltonian thermodynamics of three-dimensional dilatonic black holes

abstract:
  The action for a class of three-dimensional dilaton-gravity theories with a
cosmological constant can be recast in a Brans-Dicke type action, with its free
$\omega$ parameter. These theories have static spherically symmetric black
holes. Those with well formulated asymptotics are studied through a Hamiltonian
formalism, and their thermodynamical properties are found out. The theories
studied are general relativity ($\omega\to\infty$), a dimensionally reduced
cylindrical four-dimensional general relativity theory ($\omega=0$), and a
theory representing a class of theories ($\omega=-3$). The Hamiltonian
formalism is setup in three dimensions through foliations on the right region
of the Carter-Penrose diagram, with the bifurcation 1-sphere as the left
boundary, and anti-de Sitter infinity as the right boundary. The metric
functions on the foliated hypersurfaces are the canonical coordinates. The
Hamiltonian action is written, the Hamiltonian being a sum of constraints. One
finds a new action which yields an unconstrained theory with one pair of
canonical coordinates $\{M,P_M\}$, $M$ being the mass parameter and $P_M$ its
conjugate momenta The resulting Hamiltonian is a sum of boundary terms only. A
quantization of the theory is performed. The Schr\"odinger evolution operator
is constructed, the trace is taken, and the partition function of the canonical
ensemble is obtained. The black hole entropies differ, in general, from the
usual quarter of the horizon area due to the dilaton.


title:
The Causal Structure of QED in Curved Spacetime: Analyticity and the
  Refractive Index

abstract:
  The effect of vacuum polarization on the propagation of photons in curved
spacetime is studied in scalar QED. A compact formula is given for the full
frequency dependence of the refractive index for any background in terms of the
Van Vleck-Morette matrix for its Penrose limit and it is shown how the
superluminal propagation found in the low-energy effective action is reconciled
with causality. The geometry of null geodesic congruences is found to imply a
novel analytic structure for the refractive index and Green functions of QED in
curved spacetime, which preserves their causal nature but violates familiar
axioms of S-matrix theory and dispersion relations. The general formalism is
illustrated in a number of examples, in some of which it is found that the
refractive index develops a negative imaginary part, implying an amplification
of photons as an electromagnetic wave propagates through curved spacetime.


title:
A simple model to interpret the ultraviolet, optical and infrared
  emission from galaxies

abstract:
  We present a simple, largely empirical but physically motivated model to
interpret the mid- and far-infrared spectral energy distributions of galaxies
consistently with the emission at ultraviolet, optical and near-infrared
wavelengths. Our model relies on an existing angle-averaged prescription to
compute the absorption of starlight by dust in stellar birth clouds and in the
ambient ISM in galaxies. We compute the spectral energy distribution of the
power reradiated by dust in stellar birth clouds as the sum of three
components: a component of PAHs; a mid-IR continuum characterising the emission
from hot grains; and a component of warm grains in thermal equilibrium with
adjustable temperature. In the ambient ISM, we fix for simplicity the relative
proportions of these three components to reproduce the spectral shape of
diffuse cirrus emission in the Milky Way, and we include a component of cold
grains in thermal equilibrium with adjustable temperature. Our model can be
used to derive statistical constraints on the star formation histories and dust
contents of large samples of galaxies using UV, optical and IR observations. We
illustrate this by deriving median-likelihood estimates of the star formation
rates, stellar masses, effective dust optical depths, dust masses, and relative
strengths of different dust components of 66 well-studied nearby star- forming
galaxies from the Spitzer Infrared Nearby Galaxy Survey (SINGS). From this
analysis, we conclude that the mid- and far-IR colours of galaxies correlate
strongly with the specific star formation rate, as well as with other
galaxy-wide quantities connected to this parameter. Our model can be
straightforwardly applied to interpret UV, optical and IR spectral energy
distributions from any galaxy sample. [abridged]


title: Supersymmetry of the chiral de Rham complex II: Commuting Sectors

abstract:
  We construct two commuting N=2 structures on the space of sections of the
chiral de Rham complex (CDR) of a Calabi-Yau manifold. We use this extra
supersymmetry to construct a non-linear automorphism of CDR preserving these
N=2 structures. Finally, we show how to extend these results to construct a
commuting pair of N=4 super-vertex algebras in the Hyper-Kahler case.


title:
Equivalence and Disintegration Theorems for Fell Bundles and their
  C*-algebras

abstract:
  We study the C*-algebras of Fell bundles. In particular, we prove the
analogue of Renault's disintegration theorem for groupoids. As in the groupoid
case, this result is the key step in proving a deep equivalence theorem for the
C*-algebras of Fell bundles.


title:
Electroweak constraints on see-saw messengers and their implications for
  LHC

abstract:
  We review the present electroweak precision data constraints on the mediators
of the three types of see-saw mechanisms. Except in the see-saw mechanism of
type I, with the heavy neutrino singlets being mainly produced through their
mixing with the Standard Model leptons, LHC will be able to discover or put
limits on new scalar (see-saw of type II) and lepton (see-saw of type III)
triplets near the TeV. If discovered, it may be possible in the simplest models
to measure the light neutrino mass and mixing properties that neutrino
oscillation experiments are insensitive to.


title:
Anisotropy of superconducting single crystal SmFeAsO_(0.8)F_(0.2)
  studied by torque magnetometry

abstract:
  Single crystals of the oxypnictide superconductor SmFeAsO_(0.8)F_(0.2) with
T_c=45(1) K were investigated by torque magnetometry. The crystals of mass~0.1
mug were grown by a high-pressure cubic anvil technique. The use of a
high-sensitive piezoresistive torque sensor made it possible to study the
anisotropic magnetic properties of these tiny crystals. The anisotropy
parameter was found to be field independent, but varies strongly with
temperature ranging from 8 at T=T_c to 23 at T=0.4T_c. This unusual behavior
signals unconventional superconductivity.


title: About composition of Toeplitz operators in Segal-Bargmann Space

abstract:
  Some positive results about the composition of Toeplitz operators on the
Segal-Bargmann space are presented. A Wick symbol where it is not possible to
construct its associated Toeplitz operator is given.


title:
Higher derivative corrections to R-charged AdS_5 black holes and field
  redefinitions

abstract:
  We consider four-derivative corrections to the bosonic sector of
five-dimensional N=2 gauged supergravity. Since this theory includes the N=2
graviphoton, we consider both curvature and graviphoton field-strength terms
that show up at the four-derivative level. We construct, to linear order, the
higher-derivative corrections to the non-rotating R-charged AdS_5 black hole
and demonstrate how this solution transforms under field redefinitions.


title: On the Initial-Value Problem to the Quantum Dual BBGKY Hierarchy

abstract:
  We develop a rigorous formalism for the description of the evolution of
observables in quantum systems of particles. We construct a solution of the
initial-value problem to the quantum dual BBGKY hierarchy of equations as an
expansion over particle clusters whose evolution are governed by the
corresponding-order dual cumulant (dual semi-invariant) of the evolution
operators of finitely many particles. For initial data from the space of
sequences of bounded operators the existence and uniqueness theorem is proved.

categories: math-ph cond-mat.stat-mech math.DS math.MP


title:
Intrinsic and extrinsic corrugation of monolayer graphene deposited on
  SiO2

abstract:
  Using scanning tunneling microscopy (STM) in ultra high vacuum and atomic
force microscopy, we investigate the corrugation of graphene flakes deposited
by exfoliation on a Si/SiO2 (300 nm) surface. While the corrugation on SiO2 is
long-range with a correlation length of about 25 nm, some of the graphene
monolayers exhibit an additional corrugation with a preferential wave length of
about 15 nm. A detailed analysis shows that the long range corrugation of the
substrate is also visible on graphene, but with a reduced amplitude, leading to
the conclusion that the graphene is partly freely suspended between hills of
the substrate. Thus, the intrinsic rippling observed previously on artificially
suspended graphene can exist as well, if graphene is deposited on SiO2.


title: Group theory of icosahedral virus capsids: a dynamical top-down approach

abstract:
  We explore the use of a top-down approach to analyse the dynamics of
icosahedral virus capsids and complement the information obtained from
bottom-up studies of viral vibrations available in the literature. A normal
mode analysis based on protein association energies is used to study the
frequency spectrum, in which we reveal a universal plateau of low-frequency
modes shared by a large class of Caspar-Klug capsids. These modes break
icosahedral symmetry and are potentially relevant to the genome release
mechanism. We comment on the role of viral tiling theory in such dynamical
considerations.


title: Survival time of random walk in random environment among soft obstacles

abstract:
  We consider a Random Walk in Random Environment (RWRE) moving in an i.i.d.\
random field of obstacles. When the particle hits an obstacle, it disappears
with a positive probability. We obtain quenched and annealed bounds on the
tails of the survival time in the general $d$-dimensional case. We then
consider a simplified one-dimensional model (where transition probabilities and
obstacles are independent and the RWRE only moves to neighbour sites), and
obtain finer results for the tail of the survival time. In addition, we study
also the "mixed" probability measures (quenched with respect to the obstacles
and annealed with respect to the transition probabilities and vice-versa) and
give results for tails of the survival time with respect to these probability
measures. Further, we apply the same methods to obtain bounds for the tails of
hitting times of Branching Random Walks in Random Environment (BRWRE).


title: Proton lifetime bounds from chirally symmetric lattice QCD

abstract:
  We present results for the matrix elements relevant for proton decay in Grand
Unified Theories (GUTs). The calculation is performed at a fixed lattice
spacing a^{-1}=1.73(3) GeV using 2+1 flavors of domain wall fermions on
lattices of size 16^3\times32 and 24^3\times64 with a fifth dimension of length
16. We use the indirect method which relies on an effective field theory
description of proton decay, where we need to estimate the low energy
constants, \alpha = -0.0112(25) GeV^3 and \beta = 0.0120(26) GeV^3. We relate
these low energy constants to the proton decay matrix elements using leading
order chiral perturbation theory. These can then be combined with experimental
bounds on the proton lifetime to bound parameters of individual GUTs.


title:
State Tomography of a Chain of Qubits Embedded in a Spin Field-Effect
  Transistor via Repeated Spin-Blockade Measurements on the Edge Qubit

abstract:
  As a possible physical realization of a quantum information processor, a
system with stacked self-assembled InAs quantum dots buried in GaAs in adjacent
to the channel of a spin field-effect transistor has been proposed. In this
system, only one of the stacked qubits, i.e. the edge qubit (the qubit closest
to the channel), is measurable via "spin-blockade measurement." It is shown
that the state tomography of the whole chain of the qubits is still possible
even under such a restricted accessibility. The idea is to make use of the
entangling dynamics of the qubits. A recipe for the two-qubit system is
explicitly constructed and the effect of an imperfect fidelity of the
measurement is clarified. A general scheme for multiple qubits based on
repeated measurements is also presented.


title: Frobenius Amplitude, Ultraproducts, and Vanishing on Singular Spaces

abstract:
  When X is a singular complex projective variety, we prove a Kodaira type
vanishing theorem generalizing results of Navarro Aznar and others. This is
proved by extending the Deligne-Illusie decomposition to the Du Bois complex.
We also give a new definition of Frobenius amplitude (introduced in
math.AG/0202129) using ultraproducts.


title:
Analysis of a procedure for inserting steganographic data into VoIP
  calls

abstract:
  The paper concerns performance analysis of a steganographic method, dedicated
primarily for VoIP, which was recently filed for patenting under the name LACK.
The performance of the method depends on the procedure of inserting covert data
into the stream of audio packets. After a brief presentation of the LACK
method, the paper focuses on analysis of the dependence of the insertion
procedure on the probability distribution of VoIP call duration.


title:
Spectral analysis of transport equations with bounce-back boundary
  conditions

abstract:
  We investigate the spectral properties of the time-dependent linear transport
equation with bounce-back boundary conditions. A fine analysis of the spectrum
of the streaming operator is given and the explicit expression of the strongly
continuous streaming semigroup is derived. Next, making use of a recent result
from M. Sbihi \cite{Sbihi}, we prove, via a compactness argument, that the
essential spectrum of the transport semigroup and that of the streaming
semigroup coincide on all $L^p$-spaces with $1<p<\infty$.


title: Wave Equations on Lorentzian Manifolds and Quantization

abstract:
  This book provides a detailed introduction to linear wave equations on
Lorentzian manifolds (for vector-bundle valued fields). After a collection of
preliminary material in the first chapter one finds in the second chapter the
construction of local fundamental solutions together with their Hadamard
expansion. The third chapter establishes the existence and uniqueness of global
fundamental solutions on globally hyperbolic spacetimes and discusses Green's
operators and well-posedness of the Cauchy problem. The last chapter is devoted
to field quantization in the sense of algebraic quantum field theory. The
necessary basics on C*-algebras and CCR-representations are developed in full
detail.
  The text provides a self-contained introduction to these topics addressed to
graduate students in mathematics and physics. At the same time it is intended
as a reference for researchers in global analysis, general relativity, and
quantum field theory.


title:
Comparisons of eccentric binary black hole simulations with
  post-Newtonian models

abstract:
  We present the first comparison between numerical relativity (NR) simulations
of an eccentric binary black hole system with corresponding post-Newtonian (PN)
results. We evolve an equal-mass, non-spinning configuration with an initial
eccentricity e ~ 0.1 for 21 gravitational wave cycles before merger, and find
agreement in the gravitational wave phase with an adiabatic eccentric PN model
with 2 PN radiation reaction within 0.1 radians for 10 cycles. The NR and PN
phase difference grows to 0.7 radians by 5 cycles before merger. We find that
these results can be obtained by expanding the eccentric PN expressions in
terms of the frequency-related variable x = (omega M)^{2/3} with M the total
mass of the binary. When using instead the mean motion n = 2 \pi /P, where P is
the orbital period, the comparison leads to significant disagreements with NR.


title:
The group of order preserving automorphisms of the ring of differential
  operators on Laurent polynomial algebra in prime characteristic

abstract:
  Let $K$ be a field of characteristic $p>0$. It is proved that the group
$\Aut_{ord}(\CD (L_n))$ of order preserving automorphisms of the ring $\CD
(L_n)$ of differential operators on a Laurent polynomial algebra $L_n:=
K[x_1^{\pm 1}, ..., x_n^{\pm 1}]$ is isomorphic to a skew direct product of
groups $\Zp^n \rtimes \Aut_K(L_n)$ where $\Zp$ is the ring of $p$-adic
integers. Moreover, the group $\Aut_{ord}(\CD (L_n))$ is found explicitly.
Similarly, $\Aut_{ord}(\CDPn)\simeq \Aut_K(P_n)$ where $P_n: =K[x_1, ..., x_n]$
is a polynomial algebra.


title:
Electronic Signature of the Intermediate Phase in Ge_xSe_{1-x} Glasses:
  A Joint Theoretical and Experimental Study

abstract:
  Raman and calorimetric studies on Ge_xSe_{1-x} glasses have provided evidence
for the existence of the intermediate phase (IP) in chalcogenide and other
glasses. Here, we present X-Ray Absorption Near Edge Structure (XANES)
measurements on germanium selenide glasses in the IP composition range, and
detect an electronic signature of the IP. Ab initio molecular dynamics (MD)
based models of these glasses are discussed, and an atomistic picture of the
IP, based upon the models and available experiments is presented. We show that
these models reproduce detailed composition-dependent structure in the XANES
measurements, and otherwise appear to properly represent the structure of the
GeSe glasses near the IP.


title: An upper bound on the multiplicative energy

abstract:
  We prove that the sumset or the productset of any finite set of real numbers,
$A,$ is at least $|A|^{4/3-\epsilon},$ improving earlier bounds. Our main tool
is a new upper bound on the multiplicative energy, $E(A,A).$


title: 3-connected Planar Graph Isomorphism is in Log-space

abstract:
  We show that the isomorphism of 3-connected planar graphs can be decided in
deterministic log-space. This improves the previously known bound UL$\cap$coUL
of Thierauf and Wagner.


title: Linear Representations and Isospectrality with Boundary Conditions

abstract:
  We present a method for constructing families of isospectral systems, using
linear representations of finite groups. We focus on quantum graphs, for which
we give a complete treatment. However, the method presented can be applied to
other systems such as manifolds and two-dimensional drums. This is demonstrated
by reproducing some known isospectral drums, and new examples are obtained as
well. In particular, Sunada's method is a special case of the one presented.


title:
Magnetic and structural transitions in layered FeAs systems: AFe2As2
  versus RFeAsO compounds

abstract:
  Resistivity, specific heat and magnetic susceptibility measurements performed
on SrFe2As2 samples evidence a behavior very similar to that observed in
LaFeAsO and BaFe2As2 with the difference that the formation of the SDW and the
lattice deformation occur in a pronounced first order transition at T_0=205K.
Comparing further data evidences that the Fe-magnetism is stronger in SrFe2As2
and in EuFe2As2 than in the other layered FeAs systems investigated up to now.
Full potential LDA band structure calculations confirm the large similarity
between the compounds, especially for the relevant low energy Fe 3d states. The
relation between structural details and magnetic order is analyzed.


title:
The ternary invariant differential operators acting on the spaces of
  weighted densities

abstract:
  Over n-dimensional manifolds, I classify ternary differential operators
acting on the spaces of weighted densities and invariant with respect to the
Lie algebra of vector fields. For n=1, some of these operators can be expressed
in terms of the de Rham exterior differential, the Poisson bracket, the Grozman
operator and the Feigin-Fuchs anti-symmetric operators; four of the operators
are new, up to dualizations and permutations. For n>1, I list multidimensional
conformal tranvectors, i.e.,operators acting on the spaces of weighted
densities and invariant with respect to o(p+1,q+1), where p+q=n. Except for the
scalar operator, these conformally invariant operators are not invariant with
respect to the whole Lie algebra of vector fields.


title:
Driven and Decaying Turbulence Simulations of Low-Mass Star Formation:
  From Clumps to Cores to Protostars

abstract:
  Molecular clouds are observed to be turbulent, but the origin of this
turbulence is not well understood. As a result, there are two different
approaches to simulating molecular clouds, one in which the turbulence is
allowed to decay after it is initialized, and one in which it is driven. We use
the adaptive mesh refinement (AMR) code, Orion, to perform high-resolution
simulations of molecular cloud cores and protostars in environments with both
driven and decaying turbulence. We include self-gravity, use a barotropic
equation of state, and represent regions exceeding the maximum grid resolution
with sink particles. We analyze the properties of bound cores such as size,
shape, linewidth, and rotational energy, and we find reasonable agreement with
observation. At high resolution, the different rates of core accretion in the
two cases have a significant effect on protostellar system development. Clumps
forming in a decaying turbulence environment produce high-multiplicity
protostellar systems with Toomre-Q unstable disks that exhibit characteristics
of the competitive accretion model for star formation. In contrast, cores
forming in the context of continuously driven turbulence and virial equilibrium
form smaller protostellar systems with fewer low-mass members. Our simulations
of driven and decaying turbulence show some statistically significant
differences, particularly in the production of brown dwarfs and core rotation,
but the uncertainties are large enough that we are not able to conclude whether
observations favor one or the other.


title:
Primordial non-gaussianity, statistics of collapsed objects, and the
  Integrated Sachs-Wolfe effect

abstract:
  Any hint of non-gaussianity in the cosmological initial conditions will
provide us with a unique window into the physics of early universe. We show
that the impact of a small local primordial non-gaussianity (generated on
super-horizon scales) on the statistics of collapsed objects (such as galaxies
or clusters) can be approximated by using slightly modified, but gaussian,
initial conditions, which we describe through simple analytic expressions.
Given that numerical simulations with gaussian initial conditions are
relatively well-studied, this equivalence provides us with a simple tool to
predict signatures of primordial non-gaussianity in the statistics of collapsed
objects. In particular, we describe the predictions for non-gaussian mass
function, and also confirm the recent discovery of a non-local bias on large
scales (arXiv:0710.4560, arXiv:0801.4826) as a signature of primordial
non-gaussianity. We then study the potential of galaxy surveys to constrain
non-gaussianity using their auto-correlation and cross-correlation with the CMB
(due to the Integrated Sachs-Wolfe effect), as a function of survey
characteristics, and predict that they will eventually yield an accuracy of
Delta f_{NL} ~ 0.1 and 3 respectively, which will be better than or competitive
with (but independent of) the best predicted constraints from the CMB.
Interestingly, the cross-correlation of CMB and NVSS galaxy survey already
shows a hint of a large local primordial non-gaussianity: f_{NL} = 236 +/- 127.


title: Toy models for wrapping effects

abstract:
  The anomalous dimensions of local single trace gauge invariant operators in
N=4 supersymmetric Yang-Mills theory can be computed by diagonalizing a long
range integrable Hamiltonian by means of perturbative asymptotic Bethe ansatz.
This formalism breaks down when the number of fields of the composite operator
is smaller than the range of the Hamiltonian which coincides with the order in
perturbation theory at study. We analyze two spin chain toy models which might
shed some light on the physics behind these wrapping effects. One of them, the
Hubbard model, is known to be closely related to N=4 SYM. In this example, we
find that the knowledge of the effective spin chain description is insufficient
to reconstruct the finite size effects of the underlying electron theory. We
compute the wrapping corrections for generic states and relate them to a
Luscher like approach. The second toy models are long range integrable
Hamiltonians built from the standard algebraic Bethe anstatz formalism. This
construction is valid for any symmetry group. In particular, for non-compact
groups it exhibits an interesting relation between wrapping interactions and
transcendentality.


title: Spin squeezing and entanglement

abstract:
  What is the relation between spin squeezing and entanglement? To clarify
this, we derive the full set of generalized spin squeezing inequalities for the
detection of entanglement. These are inequalities for the mean values and
variances of the collective angular momentum components J_k. They can be used
for the experimental detection of entanglement in a system of spin-1/2
particles in which the spins cannot be individually addressed. We present
various sets of inequalities that can detect all entangled states that can be
detected based on the knowledge of: (i) the mean values and variances of J_k in
three orthogonal directions, or (ii) the variances of J_k in three orthogonal
directions, or (iii) the mean values of J_k^2 in three orthogonal directions or
(iv) the mean values and variances of J_k in arbitrary directions. We compare
our inequalities to known spin squeezing entanglement criteria and discuss to
which extent spin squeezing is related to entanglement in the reduced two-qubit
states. Finally, we apply our criteria for the detection of entanglement in
spin models, showing that they can be used to detect bound entanglement in
these systems.


title: Dijet Searches for Supersymmetry at the LHC

abstract:
  We present several strategies for searching for supersymmetry in dijet
channels that do not explicitly invoke missing energy. Preliminary
investigations suggest that signal-to-background ratios of at least 4--5 should
be achievable at the LHC, with discovery possible for squarks as heavy as ~ 1.7
TeV.