title: Network Coding in a Multicast Switch

abstract:
  The problem of serving multicast flows in a crossbar switch is considered.
Intra-flow linear network coding is shown to achieve a larger rate region than
the case without coding. A traffic pattern is presented which is achievable
with coding but requires a switch speedup when coding is not allowed. The rate
region with coding can be characterized in a simple graph-theoretic manner, in
terms of the stable set polytope of the "enhanced conflict graph". No such
graph-theoretic characterization is known for the case of fanout splitting
without coding.
  The minimum speedup needed to achieve 100% throughput with coding is shown to
be upper bounded by the imperfection ratio of the enhanced conflict graph. When
applied to KxN switches with unicasts and broadcasts only, this gives a bound
of min{(2K-1)/K,2N/(N+1)} on the speedup. This shows that speedup, which is
usually implemented in hardware, can often be substituted by network coding,
which can be done in software.
  Computing an offline schedule (using prior knowledge of the flow rates) is
reduced to fractional weighted graph coloring. A graph-theoretic online
scheduling algorithm (using only queue occupancy information) is also proposed,
that stabilizes the queues for all rates within the rate region.


title: Gaussian Belief Propagation Solver for Systems of Linear Equations

abstract:
  The canonical problem of solving a system of linear equations arises in
numerous contexts in information theory, communication theory, and related
fields. In this contribution, we develop a solution based upon Gaussian belief
propagation (GaBP) that does not involve direct matrix inversion. The iterative
nature of our approach allows for a distributed message-passing implementation
of the solution algorithm. We also address some properties of the GaBP solver,
including convergence, exactness, its max-product version and relation to
classical solution methods. The application example of decorrelation in CDMA is
used to demonstrate the faster convergence rate of the proposed solver in
comparison to conventional linear-algebraic iterative solution methods.


title: The boundary state from open string fields

abstract:
  We construct a class of BRST-invariant closed string states for any classical
solution of open string field theory. The closed string state is a nonlinear
functional of the open string field and changes by a BRST-exact term under a
gauge transformation of the solution. As a result, its contraction with an
on-shell closed string state provides a gauge-invariant observable of open
string field theory. Unlike previously known observables, however, the
contraction with off-shell closed string states in the Fock space is well
defined and regular. Moreover, we claim that the BRST-invariant closed string
state coincides, up to a possible BRST-exact term, with the boundary state of
the boundary conformal field theory which the solution is expected to describe.
Our construction requires a choice of a propagator strip. If we choose the
Schnabl propagator strip, the BRST-invariant state becomes explicitly
calculable. We calculate it for various known analytic solutions of open string
field theory and, remarkably, we find that it precisely coincides with the
boundary state without any additional BRST-exact term. Our results imply, in
particular, that the wildly oscillatory rolling tachyon solution of open string
field theory actually describes the regular closed string physics studied by
Sen using the boundary state.


title:
Validity of Equation-of-Motion Approach to Kondo Problem in the
  Large-$N$ limit

abstract:
  The Anderson impurity model for Kondo problem is investigated for arbitrary
orbit-spin degeneracy $N$ of the magnetic impurity by the equation of motion
method (EOM). By employing a new decoupling scheme, a set self-consistent
equations for the one-particle Green function are derived and numerically
solved in the large-$N$ approximation. For the particle-hole symmetric Anderson
model with finite Coulomb interaction $U$, we show that the Kondo resonance at
the impurity site exists for all $N \geq 2$. The approach removes the pathology
in the standard EOM for N=2, and has the same level of applicability as
non-crossing approximation. For N=2, an exchange field splits the Kondo
resonance into only two peaks, consist with the result from more rigorous
numerical renormalization group (NRG) method. The temperature dependence of the
Kondo resonance peak is also discussed.


title: Examples of seismic modelling

abstract:
  Findings of a few recent asteroseismic studies of the main-sequence pulsating
stars, as performed in Wojciech Dziembowski's group in Warsaw and in Michel
Breger's group in Vienna, are briefly presented and discussed. The selected
objects are three hybrid pulsators Nu Eridani, 12 Lacertae and Gamma Pegasi,
which show both Beta Cephei and SPB type modes, and the Delta Scuti type star
44 Tauri.


title: A geometric approach to integrability conditions for Riccati equations

abstract:
  Several instances of integrable Riccati equations are analyzed from the
geometric perspective of the theory of Lie systems. This provides us a unifying
viewpoint for previous approaches.


title:
Large scale galactic turbulence: can self-gravity drive the observed HI
  velocity dispersions?

abstract:
  Observations of turbulent velocity dispersions in the HI component of
galactic disks show a characteristic floor in galaxies with low star formation
rates and within individual galaxies the dispersion profiles decline with
radius. We carry out several high resolution adaptive mesh simulations of
gaseous disks embedded within dark matter haloes to explore the roles of
cooling, star-formation, feedback, shearing motions and baryon fraction in
driving turbulent motions. In all simulations the disk slowly cools until
gravitational and thermal instabilities give rise to a multi-phase medium in
which a large population of dense self-gravitating cold clouds are embedded
within a warm gaseous phase that forms through shock heating. The diffuse gas
is highly turbulent and is an outcome of large scale driving of global
non-axisymmetric modes as well as cloud-cloud tidal interactions and merging.
At low star-formation rates these processes alone can explain the observed HI
velocity dispersion profiles and the characteristic value of ~10 km/s observed
within a wide range of disk galaxies. Supernovae feedback creates a significant
hot gaseous phase and is an important driver of turbulence in galaxies with a
star-formation rate per unit area >10^-3 M_sun/yr/kpc^2.


title: Percolation on correlated networks

abstract:
  We reconsider the problem of percolation on an equilibrium random network
with degree-degree correlations between nearest-neighboring vertices focusing
on critical singularities at a percolation threshold. We obtain criteria for
degree-degree correlations to be irrelevant for critical singularities. We
present examples of networks in which assortative and disassortative mixing
leads to unusual percolation properties and new critical exponents.


title: Applied String Theory

abstract:
  This is a review. Comments are welcome.
  The observation that the structure of string theory is rich enough to include
the standard model in rough outline is an old one, starting with the early
constructions of free field constructions, orbifold theories, and in particular
Calabi-Yau compactifications in the late 1980s and early 1990s. At the time
these constructions provided a large collection of different vacua, with
thousands of explicitly constructed Calabi-Yau manifolds, and estimates of vast
numbers of bosonic models, each one associated with its own moduli space. It
was clear even then that it would be impossible to systematically search this
string vacua landscape. This, however, is not a fundamental problem. Adopting
the point of view that any physical theory has to describe not only our
universe, but all possible consistent universes, leads to the obvious strategy
of using some phenomenological input to select viable models among the ocean of
models that obviously do not describe physics as we know it.


title: Falsifying Paradigms for Cosmic Acceleration

abstract:
  Consistency relations between growth of structure and expansion history
observables exist for any physical explanation of cosmic acceleration, be it a
cosmological constant, scalar field quintessence, or a general component of
dark energy that is smooth relative to dark matter on small scales. The
high-quality supernova sample anticipated from an experiment like SNAP and CMB
data expected from Planck thus make strong predictions for growth and expansion
observables that additional observations can test and potentially falsify. We
perform an MCMC likelihood exploration of the strength of these consistency
relations based on a complete parametrization of dark energy behavior by
principal components. For LCDM, future SN and CMB data make percent level
predictions for growth and expansion observables. For quintessence, many of the
predictions are still at a level of a few percent with most of the additional
freedom coming from curvature and early dark energy. While such freedom is
limited for quintessence where phantom equations of state are forbidden, it is
larger in the smooth dark energy class. Nevertheless, even in this general
class predictions relating growth measurements at different redshifts remain
robust, although predictions for the instantaneous growth rate do not. Finally,
if observations falsify the whole smooth dark energy class, new paradigms for
cosmic acceleration such as modified gravity or interacting dark matter and
dark energy would be required.


title:
A simple, fast and stabilized flowing finite volume method for solving
  general curve evolution equations

abstract:
  A new simple Lagrangian method with favorable stability and efficiency
properties for computing general plane curve evolutions is presented. The
method is based on the flowing finite volume discretization of the intrinsic
partial differential equation for updating the position vector of evolving
family of plane curves. A curve can be evolved in the normal direction by a
combination of fourth order terms related to the intrinsic Laplacian of the
curvature, second order terms related to the curvature, first order terms
related to anisotropy and by a given external velocity field. The evolution is
numerically stabilized by an asymptotically uniform tangential redistribution
of grid points yielding the first order intrinsic advective terms in the
governing system of equations. By using a semi-implicit in time discretization
it can be numerically approximated by a solution to linear penta-diagonal
systems of equations (in presence of the fourth order terms) or tri-diagonal
systems (in the case of the second order terms). Various numerical experiments
of plane curve evolutions, including, in particular, nonlinear, anisotropic and
regularized backward curvature flows, surface diffusion and Willmore flows, are
presented and discussed.


title: Pressure control system with nonlocal friction

abstract:
  We analyze the motion of a pressure control system described by a
differential equation with nonlocal dissipative force. This system is composed
by an oscillator, a membrane and a constant force. We consider the dissipative
memory kernel consisting of two terms. One of them is described by the Dirac
delta function which represents a local friction, whereas for the second one we
consider two types: the exponential and power-law functions which represent
nonlocal dissipative forces. For these cases, one can obtain exact solutions
for the displacement and velocity. The long-time behaviors of these quantities
are also investigated.


title: Chains on suspension spectra

abstract:
  We define and study a homological version of Sullivan's rational de Rham
complex for simplicial sets. This new functor can be generalised to simplicial
symmetric spectra and in that context it has excellent categorical properties
which promise to make a number of interesting applications much more
straightforward.


title: Rescuing the Initial Mass Function for Arp 78

abstract:
  We present deep R and narrow-band Halpha images of Arp 78 obtained with the
WIYN 3.5-m telescope on Kitt Peak. GALEX observations had shown a very extended
UV structure for this system, reaching beyond the optical radius of Arp 78 and
also beyond its previously known Halpha-radius. Our new Halpha data now show
agreement not only with the spatial extent of the near- and far-UV maps, but
also in terms of structural details. Star formation rates derived from
L(Halpha) and L(FUV) are in reasonable agreement, indicating that in this case
the upper stellar IMF in the UV-bright outer arm is relatively normal. The star
forming sites in the outer arms are younger than ~15 Myr and massive enough to
properly sample the IMF up to high masses; their low optical visibility
evidently is a property of their youth.


title:
The Role of Protein Electrostatics in Facilitating the Catalysis of
  DEAD-box Proteins

abstract:
  Protein electrostatic states have been demonstrated to play crucial roles in
catalysis, ligand binding, protein stability, and in the modulation of
allosteric effects. Electrostatic states are demonstrated to appear conserved
among DEAD-box motifs and evidence is presented that the structural changes
that occur to DEAD box proteins upon ligand binding alter the DEAD-box motif
electrostatics in a way the facilitates the catalytic role of the DEAD-box
glutatmate.


title: Holographic description of asymptotically AdS_2 collapse geometries

abstract:
  The mapping between bulk supergravity fields in anti-de Sitter space and
operators in the dual boundary conformal field theory usually relies heavily on
the available global symmetries. In the present work, we study a generalization
of this mapping to time dependent situations, for the simple case of collapsing
shock waves in two spacetime dimensions. The construction makes use of
analyticity of the conformal field theory and the properties of the asymptotic
bulk geometry to reconstruct the non-analytic bulk observables. Many of the
features of this construction are expected to apply to higher dimensional
asymptotically anti-de Sitter spacetimes and their conformal field theory
duals.


title: Search for particles decaying into $Z\gamma$ at D0

abstract:
  Results on the search for particles decaying into Zgamma to llgamma are
presented. Using roughly 1 fb-1 of data, dilepton-plus-photon invariant mass
distributions have been examined for an excess over the theoretical
predictions. Having observed a good agreement between data and the standard
model prediction we set 95% C.L. upper limits on the cross section times
branching fraction (sigma x B) of the resonance Zgamma production.


title:
ESPSim: A JAVA Application for Calculating Electrostatic Potential Map
  Similarity Scores

abstract:
  ESPSim is an open source JAVA program that enables the comparisons of protein
electrostatic potential maps via the computation of an electrostatic similarity
measure. This program has been utilized to demonstrate a high degree of
electrostatic similarity among the potential maps of lysozyme proteins,
suggesting that protein electrostatic states are conserved within lysozyme
proteins. ESPSim is freely available under the AGPL License from
http://www.bioinformatics.org/project/?group_id=830


title:
Relative Spectra and Distributions of Fluences of 3He and 4He in Solar
  Energetic Particles

abstract:
  Solar Energetic Particles (SEPs) show a rich variety of spectra and relative
abundances of many ionic species and their isotopes. A long standing puzzle has
been the extreme enrichments of 3He ions. The most extreme enrichments are
observed in low fluence, the so-called impulsive, events which are believed to
be produced at the flare site in the solar corona with little scattering and
acceleration during transport to the Earth. In two earlier papers (Liu et al.
2004 and 2006) we showed how such extreme enrichments can result in the model
developed by Petrosian and Liu (2004), where ions are accelerated
stochastically by plasma waves or turbulence. In this paper we address the
relative distributions of the fluences of 3He and 4He ions presented by Ho et
al. (2005) which show that while the distribution of 4He fluence like many
other extensive characteristics of solar flare, is fairly broad, the 3He
fluence is limited to a narrow range. Moreover, the ratio of the fluences shows
a strong correlation with the 4He fluence. One of the predictions of our model
was presence of steep variation of the fluence ratio with the level of
turbulence or the rate of acceleration. We show here that this feature of the
model can reproduce the observed distribution of the fluences with very few
free parameters. The primary reason for the success of the model in both fronts
is because fully ionized 3He ion, with its unique charge to mass ratio, can
resonantly interact with more plasma modes and accelerate more readily than
4He. Essentially in most flares, all background 3He ions are accelerated to few
MeV/nucleon range, while this happens for 4He ions only in very strong events.
A much smaller fraction of 4He ions reach such energies in weaker events.


title: A Cosmic Vision Beyond Einstein

abstract:
  The acceleration of the cosmic expansion is a fundamental challenge to
standard models of particle physics and cosmology. The new physics of dark
energy may lie in the nature of gravity, the quantum vacuum, or extra
dimensions. I give a brief overview of the puzzles and possibilities of dark
energy, and discuss the confrontation of a wide variety of "beyond Einstein"
models with the latest data, showing what we currently know and what we must
seek to learn. Next generation experiments using a variety of cosmological
probes will deeply explore dark energy, dark matter, and gravitation.


title: Neutrality point of graphene with coplanar charged impurities

abstract:
  The ground-state and the transport properties of graphene subject to the
potential of in-plane charged impurities are studied. The screening of the
impurity potential is shown to be nonlinear, producing a fractal structure of
electron and hole puddles. Statistical properties of this density distribution
as well as the charge compressibility of the system are calculated in the
leading-log approximation. The conductivity depends logarithmically on
$\alpha$, the dimensionless strength of the Coulomb interaction. The theory is
asymptotically exact when $\alpha$ is small, which is the case for graphene on
a substrate with a high dielectric constant.


title: Near-Optimal Radio Use For Wireless Network Synchronization

abstract:
  We consider the model of communication where wireless devices can either
switch their radios off to save energy, or switch their radios on and engage in
communication. We distill a clean theoretical formulation of this problem of
minimizing radio use and present near-optimal solutions. Our base model ignores
issues of communication interference, although we also extend the model to
handle this requirement. We assume that nodes intend to communicate
periodically, or according to some time-based schedule. Clearly, perfectly
synchronized devices could switch their radios on for exactly the minimum
periods required by their joint schedules. The main challenge in the deployment
of wireless networks is to synchronize the devices' schedules, given that their
initial schedules may be offset relative to one another (even if their clocks
run at the same speed). We significantly improve previous results, and show
optimal use of the radio for two processors and near-optimal use of the radio
for synchronization of an arbitrary number of processors. In particular, for
two processors we prove deterministically matching $\Theta(\sqrt{n})$ upper and
lower bounds on the number of times the radio has to be on, where $n$ is the
discretized uncertainty period of the clock shift between the two processors.
(In contrast, all previous results for two processors are randomized.) For
$m=n^\beta$ processors (for any $\beta < 1$) we prove $\Omega(n^{(1-\beta)/2})$
is the lower bound on the number of times the radio has to be switched on (per
processor), and show a nearly matching (in terms of the radio use)
$\~{O}(n^{(1-\beta)/2})$ randomized upper bound per processor, with failure
probability exponentially close to 0. For $\beta \geq 1$ our algorithm runs
with at most $poly-log(n)$ radio invocations per processor. Our bounds also
hold in a radio-broadcast model where interference must be taken into account.


title: Scenario for Fractional Quantum Hall Effect in Bulk Isotropic Materials

abstract:
  We investigate the possibility of a strongly correlated Fractional Quantum
Hall (FQH) state in bulk three dimensional isotropic (not layered) materials.
We find that a FQH state can exist at low densities only if it is accompanied
by a staging transition in which the electrons re-organize themselves in
layers, perpendicular to the magnetic field, at distances of order the magnetic
length apart. The Hartree energy associated to the staging transition is
off-set by the correlation Fock energy of the 3D FQH state. We obtain the phase
diagram of bulk electrons in a magnetic field subject to Coulomb interactions
as a function of carrier density and lattice constant. At very low densities,
the 3D FQH state exhibits a transition to a 3D Wigner crystal state stabilized
by phonon correlations.


title: A Simple Comptonization Model

abstract:
  We present an empirical model of Comptonization for fitting the spectra of
X-ray binaries. This model, "simpl", has been developed as a package
implemented in XSPEC. With only two free parameters, simpl is competitive as
the simplest empirical model of Compton scattering. Unlike other empirical
models, such as the standard power-law model, simpl incorporates the basic
physics of Compton scattering of soft photons by energetic coronal electrons.
Using a simulated spectrum, we demonstrate that simpl closely matches the
behavior of physical Comptonization models which consider the effects of
optical depth, coronal electron temperature, and geometry. We present fits to
RXTE spectra of the black-hole transient H1743-322 and a BeppoSAX spectrum of
LMC X-3 using both simpl and the standard power-law model. A comparison of the
results shows that simpl gives equally good fits and a comparable spectral
index, while eliminating the troublesome divergence of the standard power-law
model at low energies. Importantly, simpl is completely flexible and can be
used self-consistently with any seed spectrum of photons. We show that simpl -
unlike the standard power law - teamed up with diskbb (the standard model of
disk accretion) gives results for the inner-disk radius that are unaffected by
strong Comptonization, a result of great importance for the determination of
black hole spin via the continuum-fitting method.


title: A lattice study of light scalar tetraquarks

abstract:
  The observed mass pattern of scalar resonances below 1 GeV gives preference
to the tetraquark assignment over the conventional $\bar qq$ assignment for
these states. We present a search for tetraquarks with isospins 0, 1/2, 1 in
lattice QCD, where the isospin channels 1/2 and 1 have not been studied before.
We determine three energy levels in each isospin channel using the variational
method. The scattering states and possible tetraquark states are distinguished
by considering the volume-dependence of spectral weights and by considering the
time-dependence of correlators near t~T/2. We find no indication for light
tetraquarks at our range of pion masses 344-576 MeV.


title:
Core instability models of giant planet accretion II: forming planetary
  systems

abstract:
  We develop a simple model for computing planetary formation based on the core
instability model for the gas accretion and the oligarchic growth regime for
the accretion of the solid core. In this model several planets can form
simultaneously in the disc, a fact that has important implications specially
for the changes in the dynamic of the planetesimals and the growth of the cores
since we consider the collision between them as a source of potential growth.
The type I and II migration of the embryos and the migration of the
planetesimals due to the interaction with the disc of gas are also taken into
account. With this model we consider different initial conditions to generate a
variety of planetary systems and analyse them statistically. We explore the
effects of using different type I migration rates on the final number of
planets formed per planetary system such as on the distribution of masses and
semimajor axis of extrasolar planets, where we also analyse the implications of
considering different gas accretion rates. A particularly interesting result is
the generation of a larger population of habitable planets when the gas
accretion rate and type I migration are slower.


title: Unbiased bases (Hadamards) for 6-level systems: Four ways from Fourier

abstract:
  In quantum mechanics some properties are maximally incompatible, such as the
position and momentum of a particle or the vertical and horizontal projections
of a 2-level spin. Given any definite state of one property the other property
is completely random, or unbiased. For N-level systems, the 6-level ones are
the smallest for which a tomographically efficient set of N+1 mutually unbiased
bases (MUBs) has not been found. To facilitate the search, we numerically
extend the classification of unbiased bases, or Hadamards, by incrementally
adjusting relative phases in a standard basis. We consider the non-unitarity
caused by small adjustments with a second order Taylor expansion, and choose
incremental steps within the 4-dimensional nullspace of the curvature. In this
way we prescribe a numerical integration of a 4-parameter set of Hadamards of
order 6.


title:
Drag-Gravity torques on galaxies in clusters: radial small-scale
  alignment effects

abstract:
  We calculate the torque on galaxies in clusters due to gravity and to
dynamical friction forces in order to study the possible origin of small-scale
alignment effects as the result of interactions with their environment. The
equation of motion for the position angle of a galaxy is derived by using a ple
model. We find that weak radial alignment effects can be produced by this
mechanism involving only the most massive galaxies. We also introduce a
dependence on the cluster eccentricity to our equations in order to explore the
alignment of galaxies with the cluster's major axis. We find that in the inner
regions of high eccentricity clusters, alignments of massive galaxies with the
cluster's major axis dominate over the radial ones. This mechanism could
account for the observed alignment effects of the most massive galaxies with
the major axis of their host cluster. Our results suggest that dynamical
friction is a viable generator of alignment only for the most massive cluster
galaxies. For the observed alignments of normal galaxies a primordial origin
has to be explored.


title: The influence of gas-kinetic evolution on plasma reactions

abstract:
  Plasmas in which there is a threshold for a dominant reaction to take place
(such as recombination or attachment) will have particle distributions that
evolve as the reaction progresses. The form of the Boltzmann collision term in
such a context will cause the distribution to drift from its initial form, and
so cause for example temperature fluctuations in the plasma if the distribution
is originally Maxwellian. This behaviour will impact on the relevant reaction
rates in a feedback loop that is missing from simple chemical kinetic
descriptions since the plasma cannot be considered to be isothermal, as is the
case in the latter approach. In this article we present a simple kinetic model
that captures these essential features, showing how cumulative differences in
the instantaneous species levels can arise over the purely chemical kinetic
description, with implications for process yields and efficiencies.


title:
The QCD EoS from simulations on BlueGene L Supercomputers at LLNL and
  NYBlue

abstract:
  We present results for the QCD Equation of State (EoS) obtained using
simulations of lattice QCD at zero chemical potential. Our high statistics
results compare improved asqtad and p4fat3 staggered quarks on lattices with a
temporal extent N_tau = 6 and 8 and light quark masses approximately one fifth
and one tenth the strange quark mass. We find that the two actions give
consistent results and estimate that the trace anomaly (epsilon - 3p)/T^4
obtained on N_tau = 8 lattices represents the continuum value to better than
20% uncertainty over the temperature range 140-700 MeV. The precision in the
estimates of energy density and pressure are better, therefore, we conclude
that lattice estimates of the energy density and pressure should be used in the
phenomenological analysis of RHIC and LHC data. We also find a consistent
picture of the crossover temperature from all observables studied, with the
best estimated range to be 185-195 MeV. These calculations are being carried
out on the IBM BlueGene/L supercomputer at Lawrence Livermore National
Laboratory and at the New York Center for Computational Science (NYBlue).


title: Emergence of species in evolutionary simulated annealing

abstract:
  Which factors govern the evolution of mutation rates and emergence of
species? Here, we address this question using a first principles model of life
where population dynamics of asexual organisms is coupled to molecular
properties and interactions of proteins encoded in their genomes. Simulating
evolution of populations, we found that fitness increases in punctuated steps
via epistatic events, leading to formation of stable and functionally
interacting proteins. At low mutation rates, species - populations of organisms
with identical genotypes - form, while at higher mutation rates, species are
lost through delocalization in sequence space without an apparent loss of
fitness. However, when mutation rate was a selectable trait, the population
initially maintained high mutation rate until a high fitness level is reached,
after which organisms with low mutation rates are gradually selected, with the
population eventually reaching mutation rates comparable to those of modern
DNA-based organisms. These results provide microscopic insights into the
dynamic fitness landscape of asexual populations of unicellular organisms.


title: Reflection matrices for the $U_{q}[spo(2n|2m)]$ vertex model

abstract:
  We propose a classification of the solutions of the graded reflection
equations to the $U_{q}[spo(2n|2m)]$ vertex model. We find twelve distinct
classes of reflection matrices such that four of them are diagonal. In the
non-diagonal matrices the number of free parameters depending on the number of
bosonic ($2n$) and fermionic ($2m$) degrees of freedom while in the diagonal
ones we find solutions with at most one free parameter.


title:
High-accuracy waveforms for binary black hole inspiral, merger, and
  ringdown

abstract:
  The first spectral numerical simulations of 16 orbits, merger, and ringdown
of an equal-mass non-spinning binary black hole system are presented.
Gravitational waveforms from these simulations have accumulated numerical phase
errors through ringdown of ~0.1 radian when measured from the beginning of the
simulation, and ~0.02 radian when waveforms are time and phase shifted to agree
at the peak amplitude. The waveform seen by an observer at infinity is
determined from waveforms computed at finite radii by an extrapolation process
accurate to ~0.01 radian in phase. The phase difference between this waveform
at infinity and the waveform measured at a finite radius of r=100M is about
half a radian. The ratio of final mass to initial mass is M_f/M = 0.95162 +-
0.00002, and the final black hole spin is S_f/M_f^2=0.68646 +- 0.00004.


title: Spacelike distance from discrete causal order

abstract:
  Any discrete approach to quantum gravity must provide some prescription as to
how to deduce continuum properties from the discrete substructure. In the
causal set approach it is straightforward to deduce timelike distances, but
surprisingly difficult to extract spacelike distances, because of the unique
combination of discreteness with local Lorentz invariance in that approach. We
propose a number of methods to overcome this difficulty, one of which
reproduces the spatial distance between two points in a finite region of
Minkowski space. We provide numerical evidence that this definition can be used
to define a `spatial nearest neighbor' relation on a causal set, and conjecture
that this can be exploited to define the length of `continuous curves' in
causal sets which are approximated by curved spacetime. This provides evidence
in support of the ``Hauptvermutung'' of causal sets.


title: Rotational Line Emission from Water in Protoplanetary Disks

abstract:
  Circumstellar disks provide the material reservoir for the growth of young
stars and for planet formation. We combine a high-level radiative transfer
program with a thermal-chemical model of a typical T Tauri star disk to
investigate the diagnostic potential of the far-infrared lines of water for
probing disk structure. We discuss the observability of pure rotational H2O
lines with the Herschel Space Observatory, specifically the residual gas where
water is mainly frozen out. We find that measuring both the line profile of the
ground 110-101 ortho-H2O transition and the ratio of this line to the 312-303
and 221-212 line can provide information on the gas phase water between 5-100
AU, but not on the snow line which is expected to occur at smaller radii.


title: MAXI and GLAST Studies of Jets in Active Galaxies

abstract:
  The recent launch of Fermi / GLAST - coinciding with the MAXI workshop -
opens a new era for studies of jet-dominated active galaxies, known as blazars.
While the emission processes operating in various spectral bands in blazars are
reasonably well understood, the knowledge of the details of the structure of
the jet, location of the dissipation region with respect to the accreting black
hole, and coupling of the jet to the accretion process are known only at a
rudimentary level. Blazars are variable, and this provides an opportunity to
use the variability in various bands - and in particular, the relationship of
respective time series to each other - to explore the relative location of
regions responsible for emission in the respective bands. Observationally, this
requires well-sampled time series in as many spectral bands as possible. To
this end, with its all-sky, sensitive monitoring capability, the recently
launched GLAST, and MAXI, to be deployed in 2009, are the most promising
instruments bound to provide good sampling in respectively the energetic
gamma-ray, and the soft X-ray band. This paper highlights the inferences
regarding blazar jets that can be gleaned from such joint observations.


title:
Kondo decoherence: finding the right spin model for iron impurities in
  gold and silver

abstract:
  We exploit the decoherence of electrons due to magnetic impurities, studied
via weak localization, to resolve a longstanding question concerning the
classic Kondo systems of Fe impurities in the noble metals gold and silver:
which Kondo-type model yields a realistic description of the relevant multiple
bands, spin and orbital degrees of freedom? Previous studies suggest a fully
screened spin $S$ Kondo model, but the value of $S$ remained ambiguous. We
perform density functional theory calculations that suggest $S = 3/2$. We also
compare previous and new measurements of both the resistivity and decoherence
rate in quasi 1-dimensional wires to numerical renormalization group
predictions for $S=1/2,1$ and 3/2, finding excellent agreement for $S=3/2$.


title:
Polaron formation in the optimally doped ferromagnetic manganites
  La0.7Ba0.3MnO3 and La0.7Ba0.3MnO3

abstract:
  The nature of the polarons in the optimally doped colossal magnetoresistive
(CMR) materials La0.7Ba0.3MnO3 (LBMO) and La0.7Sr0.3MnO3 (LSMO) is studied by
elastic and inelastic neutron scattering. In both materials, dynamic nanoscale
polaron correlations develop abruptly in the ferromagnetic state. However, the
polarons are not able to lock-in to the lattice and order, in contrast to the
behavior of La0.7Ca0.3MnO3. Therefore ferromagnetic order in LBMO and LSMO
survives their formation, explaining the conventional second order nature of
the ferromagnetic--paramagnetic transition. Nevertheless, the results
demonstrate that the fundamental mechanism of polaron formation is a universal
feature of these ferromagnetic perovskite manganites.


title:
Finite Word Length Effects on Transmission Rate in Zero Forcing Linear
  Precoding for Multichannel DSL

abstract:
  Crosstalk interference is the limiting factor in transmission over copper
lines. Crosstalk cancelation techniques show great potential for enabling the
next leap in DSL transmission rates. An important issue when implementing
crosstalk cancelation techniques in hardware is the effect of finite world
length on performance. In this paper we provide an analysis of the performance
of linear zero-forcing precoders, used for crosstalk compensation, in the
presence of finite word length errors. We quantify analytically the trade off
between precoder word length and transmission rate degradation. More
specifically, we prove a simple formula for the transmission rate loss as a
function of the number of bits used for precoding, the signal to noise ratio,
and the standard line parameters. We demonstrate, through simulations on real
lines, the accuracy of our estimates. Moreover, our results are stable in the
presence of channel estimation errors. Finally, we show how to use these
estimates as a design tool for DSL linear crosstalk precoders. For example, we
show that for standard VDSL2 precoded systems, 14 bits representation of the
precoder entries results in capacity loss below 1% for lines over 300m.


title:
Values of Noncommutative Polynomials, Lie Skew-Ideals and the Tracial
  Nullstellensatz

abstract:
  A subspace of an algebra with involution is called a Lie skew-ideal if it is
closed under Lie products with skew-symmetric elements. Lie skew-ideals are
classified in central simple algebras with involution (there are eight of them
for involutions of the first kind and four for involutions of the second kind)
and this classification result is used to characterize noncommutative
polynomials via their values in these algebras. As an application, we deduce
that a polynomial is a sum of commutators and a polynomial identity of $d\times
d$ matrices if and only if all of its values in the algebra of $d\times d$
matrices have zero trace.


title: Giant flexoelectric effect in two-dimensional boron-nitride sheets

abstract:
  We find, with the use of first-principles calculations, that a
single-atom-thick boron-nitride (BN) sheet exhibits an unusual nonlinear
electromechanical effect: it becomes macroscopically polarized when bent
out-of-plane. The direction of the induced polarization is in the plane of the
film and it depends non-analitically on the corrugation wave vector k. The
magnitude of the polarization can reach very high values in spite of being at
least quadratic in atomic displacements due to BN sheets being able to tolerate
large mechanical strains. The discovered effect can find many applications, in
particular, in a new type of efficient and reliable nanogenerators.


title: Timelike Killing Fields and Relativistic Statistical Mechanics

abstract:
  For spacetimes with timelike Killing fields, we introduce a
"Fermi-Walker-Killing" coordinate system and use it to prove a Liouville
Theorem for an appropriate volume element of phase space for a statistical
mechanical system of particles. We derive an exact relativistic formula for the
Helmholtz free energy of an ideal gas and compare it, for a class of
spacetimes, to its Newtonian analog, derived both independently and as the
Newtonian limit of our formula. We also find the relativistic thermodynamic
equation of state. Specific examples are given in Kerr spacetime.


title:
Large and Flat Graphene Flakes Produced by Epoxy Bonding and Reverse
  Exfoliation of Highly Oriented Pyrolitic Graphite

abstract:
  We present a fabrication method producing large and flat graphene flakes that
have a few layers down to a single layer based on substrate bonding of a thick
sample of highly oriented pyrolytic graphite (HOPG), followed by its controlled
exfoliation down to the few to single graphene atomic layers. As the graphite
underlayer is intimately bonded to the substrate during the exfoliation
process, the obtained graphene flakes are remarkably large and flat and present
very few folds and pleats. The high occurrence of single layered graphene
sheets having tens of micron wide in lateral dimensions is assessed by
complementary probes including spatially resolved Micro-Raman Spectroscopy,
Atomic Force Microscopy and Electrostatic Force Microscopy. This versatile
method opens the way of deposition of graphene on any substrates including
flexible ones.


title:
Asymptotic stability of small solitons in the discrete nonlinear
  Schrodinger equation in one dimension

abstract:
  Asymptotic stability of small solitons in one dimension is proved in the
framework of a discrete nonlinear Schrodinger equation with septic and higher
power-law nonlinearities and an external potential supporting a simple isolated
eigenvalue. The analysis relies on the dispersive decay estimates from
Pelinovsky & Stefanov (2008) and the arguments of Mizumachi (2008) for a
continuous nonlinear Schrodinger equation in one dimension. Numerical
simulations suggest that the actual decay rate of perturbations near the
asymptotically stable solitons is higher than the one used in the analysis.


title: Hypersurfaces of Constant Curvature in Hyperbolic Space I

abstract:
  We investigate the problem of finding complete strictly convex hypersurfaces
of constant curvature in hyperbolic space with a prescribed asymptotic boundary
at infinity for a general class of curvature functions.


title:
New period-luminosity and period-color relations of classical Cepheids:
  III. Cepheids in SMC

abstract:
  The photometric data for 460 classical, fundamental-mode Cepheids in the SMC
with log P > 0.4 measured by Udalski et al. have been analyzed for their P-C
and P-L relations, and for the variation of amplitude across the instability
strip in a similar way that was done in Papers I and II of this series. The SMC
Cepheids are bluer in (B-V) at a given period than for both the Galaxy and the
LMC. Their P-C relation in (B-V) is best fit by two lines intersecting at P=10
d. Their break must necessarily exist also in the P-L relations in B and/or V,
but remains hidden in the magnitude scatter. An additional pronounced break of
the P-L relations in B, V, and I occurs at P=2.5 d. The observed slope of the
lines of constant period in the HR diagram agrees with the theoretical
expectation from the pulsation equation. The largest amplitude Cepheids for
periods less than 13 days occur near the blue edge of the instability strip.
The sense is reversed in the period interval from 13 to 20 days, as in the
Galaxy and the LMC. The SMC P-L relation is significantly flatter than that for
the Galaxy, NGC 3351, 4321, M31, all of which have nearly the same steep slope.
The SMC P-L slope is intermediate between that of these steep slope cases and
the very shallow slope of Cepheids in the lower metallicity galaxies of NGC
3109 and Sextans A/B, consistent with the premise that the Cepheid P-L relation
varies from galaxy-to-galaxy as function of metallicity. Failure to take into
account the slope differences in the P-L relation as a function of metallicity
using Cepheids as distance indicators results in incorrect Cepheid distances.
Part of the 15% difference between our long distance scale - now independently
supported by TRGB distances - and that of the HST Key Project short scale is
due to the effect of using an inappropriate P-L relation.


title: Hypersurfaces of Constant Curvature in Hyperbolic Space II

abstract:
  We find complete hypersurfaces of constant curvature in hyperbolic space with
a prescribed asymptotic boundary at infinity for a general class of (elliptic)
curvature functions which includes the higher order mean curvatures and their
curvature quotients.


title:
Properties of Axial-vector Mesons and Charmless B Decays: B -> VV, VA,
  AA

abstract:
  I introduce the properties of the light axial-vector mesons. The branching
ratios, longitudinal fractions and direct CP asymmetries of the related
charmless two-body B decays into final states involving two axial-vector mesons
($AA$) or one vector and one axial-vector meson ($VA$) are discussed within the
framework of QCD factorization.


title: Scattering of low Reynolds number swimmers

abstract:
  We describe the consequences of time reversal invariance of the Stokes'
equations for the hydrodynamic scattering of two low Reynolds number swimmers.
For swimmers that are related to each other by a time reversal transformation
this leads to the striking result that the angle between the two swimmers is
preserved by the scattering. The result is illustrated for the particular case
of a linked-sphere model swimmer. For more general pairs of swimmers, not
related to each other by time reversal, we find hydrodynamic scattering can
alter the angle between their trajectories by several tens of degrees. For two
identical contractile swimmers this can lead to the formation of a bound state.


title: The stable moduli space of flat connections over a surface

abstract:
  We compute the homotopy type of the moduli space of flat, unitary connections
over aspherical surfaces, after stabilizing with respect to the rank of the
underlying bundle. Over the orientable surface M^g, we show that this space has
the homotopy type of the infinite symmetric product of M^g, generalizing a
well-known fact for the torus. Over a non-orientable surface, we show that this
space is homotopy equivalent to a disjoint union of two tori, whose common
dimension corresponds to the rank of the first (co)homology group of the
surface. Similar calculations are provided for products of surfaces, and show a
close analogy with the Quillen-Lichtenbaum conjectures in algebraic K-theory.
The proofs utilize Tyler Lawson's work in deformation K-theory, and rely
heavily on Yang-Mills theory and gauge theory.


title: A homotopy-theoretic view of Bott-Taubes integrals and knot spaces

abstract:
  We construct cohomology classes in the space of knots by considering a bundle
over this space and "integrating along the fiber" classes coming from the
cohomology of configuration spaces using a Pontrjagin-Thom construction. The
bundle we consider is essentially the one considered by Bott and Taubes, who
integrated differential forms along the fiber to get knot invariants. By doing
this "integration" homotopy-theoretically, we are able to produce integral
cohomology classes. We then show how this integration is compatible with the
homology operations on the space of long knots, as studied by Budney and Cohen.
In particular we derive a product formula for evaluations of cohomology classes
on homology classes, with respect to connect-sum of knots.


title:
Lateral Casimir forces on parallel plates and concentric cylinders with
  corugations

abstract:
  In this paper we are giving a quantitative description of two different
configurations for noncontact gears. We consider the solutions from a
perturbative calculation for two semitransparent parallel plates and concentric
cylinders both with corrugations on the inner surfaces. In the case of
corrugated parallel plates we discuss results from first- and second-order
perturbation calculation in the corrugation amplitudes and we will concentrate
on the first-order perturbation for the case of the corrugated concentric
cylinders (the second order calculation is under study), both for the weak and
strong couplings. We compare the perturbative results with the results from the
PFA and an exact weak coupling calculation.


title:
Leading- and next-to-leading-order lateral Casimir force on corrugated
  surfaces

abstract:
  We derive explicit analytic expressions for the lateral force for two
different configurations with corrugations, parallel plates and concentric
cylinders. By making use of the multiple scattering formalism, we calculate the
force for a scalar field under the influence of a delta-function potential that
has sinusoidal dependence in one direction simulating the corrugations. By
making a perturbative expansion in the amplitude of the corrugation we find the
leading order for the corrugated concentric cylinders and the next-to-leading
order for the corrugated parallel plates.


title:
Junctions of Spin-Incoherent Luttinger Liquids with Ferromagnets and
  Superconductors

abstract:
  We discuss the properties of a strongly interacting spin-charge separated one
dimensional system coupled to ferromagnets and/or superconductors. Our results
are valid for arbitrary temperatures with respect to the spin energy, but
require temperature be small compared to the charge energy. We focus mainly on
the spin-incoherent regime where temperature is large compared to the spin
energy, but small compared to the charge energy. In the case of a ferromagnet
we study spin pumping and the renormalized dynamics of a precessing magnetic
order parameter. We find the interaction-dependent temperature dependence of
the spin pumping can be qualitatively different in the spin-incoherent regime
from the Luttinger liquid regime, allowing an identification of the former.
Likewise, the temperature dependence of the renormlized magnetization dynamics
can be used to identify spin-incoherent physics. For the case of a
spin-incoherent Luttinger liquid coupled to two superconductors, we compute the
ac and dc Josephson current for a wire geometry in the limit of tunnel coupled
superconductors. Both the ac and dc response contain "smoking gun" signatures
that can be used to identify spin-incoherent behavior. Experimental
requirements for the observation of these effects are laid out.


title: Spectral Theory of Elliptic Operators in Exterior Domains

abstract:
  We consider various closed (and self-adjoint) extensions of elliptic
differential expressions of the type $\cA=\sum_{0\le |\alpha|,|\beta|\le
m}(-1)^\alpha D^\alpha a_{\alpha, \beta}(x)D^\beta$, $a_{\alpha,
\beta}(\cdot)\in C^{\infty}({\overline\Omega})$, on smooth (bounded or
unbounded) domains in $\bbR^n$ with compact boundary. Using the concept of
boundary triples and operator-valued Weyl-Titchmarsh functions, we prove
various trace ideal properties of powers of resolvent differences of these
closed realizations of $\cA$ and derive estimates on eigenvalues of certain
self-adjoint realizations in spectral gaps of the Dirichlet realization.
  Our results extend classical theorems due to Visik, Povzner, Birman, and
Grubb.


title: $N+1$ formalism in Einstein-Gauss-Bonnet gravity

abstract:
  Towards the investigation of the full dynamics in higher-dimensional and/or
stringy gravitational model, we present the basic equations of the
Einstein-Gauss-Bonnet gravity theory. We show $(N+1)$-dimensional version of
the ADM decomposition including Gauss-Bonnet terms, which shall be the standard
approach to treat the space-time as a Cauchy problem. Due to the quasi-linear
property of the Gauss-Bonnet gravity, we find that the evolution equations can
be in a treatable form in numerics. We also show the conformally-transformed
constraint equations for constructing an initial data. We discuss how the
constraints can be simplified by tuning the powers of conformal factors. Our
equations can be used both for timelike and spacelike foliations.


title:
Novel Quantum Criticality in CeRu$_2$Si$_2$ near Absolute Zero Observed
  by Thermal Expansion and Magnetostriction

abstract:
  We report linear thermal expansion and magnetostriction measurements for
CeRu$_2$Si$_2$ in magnetic fields up to 52.6 mT and at temperatures down to 1
mK. At high temperatures, this compound showed Landau-Fermi-liquid behavior:
The linear thermal expansion coefficient and the magnetostriction coefficient
were proportional to the temperature and magnetic field, respectively. In
contrast, a pronounced non-Fermi-liquid effect was found below 50 mK. The
negative contribution of thermal expansion and magnetostriction suggests the
existence of an additional quantum critical point.


title: Volume dependence of Fisher's zeros

abstract:
  We study the location of the partition function zeros in the complex beta
plane (Fisher's Zeros) for SU(2) lattice gauge theory on L^4 lattices. We
discuss recent attempts to locate complex zeros for L=4 and 6. We compare
results obtained using various polynomial approximations of the logarithm of
the density of states and a straightforward MC reweighting. We conclude that
the method based on a combination of discrete Chebyshev orthogonality and
patching plaquette distributions at different beta provides the more reliable
estimates.


title:
On connectivity of fibers with positive marginals in multiple logistic
  regression

abstract:
  In this paper we consider exact tests of a multiple logistic regression,
where the levels of covariates are equally spaced, via Markov beses. In usual
application of multiple logistic regression, the sample size is positive for
each combination of levels of the covariates. In this case we do not need a
whole Markov basis, which guarantees connectivity of all fibers. We first give
an explicit Markov basis for multiple Poisson regression. By the Lawrence
lifting of this basis, in the case of bivariate logistic regression, we show a
simple subset of the Markov basis which connects all fibers with a positive
sample size for each combination of levels of covariates.


title: Bounds on the roots of the Steiner polynomial

abstract:
  We consider the Steiner polynomial of a C^2 convex body K in R^n (n \leq 5).
The opposites of the real parts of the roots of the Steiner polynomial are
bounded below by the minimum value and above by the maximum value of the
principal radii of curvature of the boundary of K.


title:
Coherent control of localization, entanglement, and state superpositions
  in a double quantum dot with two electrons

abstract:
  We have recently proposed a quantum control method based on the knowledge of
the energy spectrum as a function of an external control parameter [Phys. Rev.
Lett. {\bf 99}, 036806 (2007)]. So far, our method has been applied to connect
the ground state to target states that were in all cases energy eigenstates. In
this paper we extend that method in order to obtain more general target states,
working, for concreteness, with a system of two interacting electrons confined
in semiconductor double quantum wells. Namely, we have shown that the same
basic method can be employed to obtain localization, entanglement, and general
superpositions of eigenstates of the system.


title:
The Non-universal behaviour of Cold Fermi Condensates with Narrow
  Feshbach Resonances

abstract:
  In this paper we construct an effective field theory for a condensate of cold
Fermi atoms whose scattering is controlled by a narrow Feshbach resonance. We
show how, from first principles, it permits a hydrodynamic description of the
BEC-BCS crossover from which the equation of state, intimately related to the
speed of sound, can be derived. Specifically, we stress the non-universal
behaviour of the equation of state at the unitary limit of infinite scattering
length that arises when either, or both, of the range of the inter-atomic force
and the scale of the molecular field become large.


title: The magnetohydrodynamics model of twin kilohertz QPOs in LMXBs

abstract:
  We suggest an explanation for the twin kilohertz quasi-periodic oscillations
(kHz QPOs) in low-mass X-ray binaries (LMXBs) based on magnetohydrodynamics
(MHD) oscillation modes in neutron star magnetospheres. Including the effect of
the neutron star spin, we derive several MHD wave modes by solving the
dispersion equations, and propose that the coupling of the two resonant MHD
modes may lead to the twin kHz QPOs. This model naturally relates the upper,
lower kHz QPO frequencies with the spin frequencies of the neutron stars, and
can well account for the measured data of six LMXBs.


title: Visualization System for Burrowing Organisms in Granular Substrates

abstract:
  This fluid dynamics video demonstrates the capabilities of an experimental
setup to visualize organisms burrowing in granular substrates. The setup
consists of a tank filled with 1mm soda-lime glass beads, backlit by halogen
lights. The walls can be moved such that the space bound by them can expand or
contract to fit various organisms. A recirculation system oxygenates and cools
the salt water that flows through the substrate. The video shows the burrowing
behavior of a razor clam (Ensis directus) and a quahog (Mercenaria mercenaria).
Both animals inflate their foot with blood, making the foot a terminal anchor
against which they pull their shell downwards. Deformation of the granular
substrate can be seen around the animals as they advance downwards.


title: Self-mapping degrees of torus bundles and torus semi-bundles

abstract:
  Each closed oriented 3-manifold $M$ is naturally associated with a set of
integers $D(M)$, the degrees of all self-maps on $M$. $D(M)$ is determined for
each torus bundle and torus semi-bundle $M$. The structure of torus semi-bundle
is studied in detail. The paper is a part of a project to determine $D(M)$ for
all 3-manifolds in Thurston's picture.


title: The bounce-splash of a viscoelastic drop

abstract:
  This is an entry for the Gallery of Fluid Motion of the 61st Annual Meeting
of the APS-DFD (fluid dynamics videos). This video shows the collision and
rebound of viscoelastic drops against a solid wall. Using a high speed camera,
the process of approach, contact and rebound of drops of a viscoelastic liquid
is observed. We found that these drops first splash, similar to what is
observed in Newtonian colliding drops; after a few instants, the liquid
recoils, recovering its original drop shape and bounce off the wall.


title: Self-mapping Degrees of 3-Manifolds

abstract:
  For each closed oriented 3-manifold $M$ in Thurston's picture, the set of
degrees of self-maps on $M$ is given.


title:
Electroproduction of electron-positron pair in oriented crystal at high
  energy

abstract:
  The process of electroproduction of the electron-positron pair by high energy
electron in an oriented single crystal is investigated. Two contributions are
considered: the direct (one-step) process via the virtual intermediate photon
and the cascade(two-step) process when the electron emits the real photon
moving in the field of axis and afterwards the photon converts into the pair.
The spectrum of created positron(electron) is found. It is shown that the
probability of the process is strongly enhanced comparing with the
corresponding amorphous medium.


title: GOLF: a new proxy for solar magnetism

abstract:
  Solar magnetism is measured with different indexes: for instance the MPSI and
the MWSI, number of sunspots, radio flux at 10.7 cm, Ca II K, Mg II K, EUV, He
I or L_alpha. Bachmann & White (1994) had compared these indicators of the
solar activity showing a hysteresis of the solar cycle variations and a time
lag between these indices not related to instrumental effects. Later on, Ozguc
& Atac (2001) extended this study of hysteresis phenomenon between Flare index
and other solar indices (mean magnetic field, coronal index). In its original
working configuration, GOLF/SoHO was able to measure during 26 days the solar
mean magnetic field (Garcia et al. 1999). We check here if the velocity data
could be used as another solar magnetism proxy with the advantage of having a
duty cycle >95% during the last 12 years. We will compare the GOLF data with
some of the above-mentioned solar activity indexes.


title: Noncommutative resolution, F-blowups and D-modules

abstract:
  We explain the isomorphism between the $G$-Hilbert scheme and the F-blowup
from the noncommutative viewpoint after Van den Bergh. In doing this, we
immediately and naturally arrive at the notion of $D$-modules. We also find, as
a byproduct, a canonical way to construct a noncommutative resolution at least
for a few classes of singularities in positive characteristic.


title: Constraints on spin observables

abstract:
  Positivity constrains the allowed domain for sets of spin observables in
exclusive or inclusive reactions. Examples are given for strangeness-echange
reactions and photoproduction.


title: Analysis of the normal state magnetotransport in CeIrIn${_5}$

abstract:
  We present an analysis of the normal state magnetotransport in the heavy
fermion superconductor CeIrIn${_5}$. The Hall effect and the transverse
magnetoresistance in this material do not appear to be uniquely correlated, as
inferred from the field dependence of the current ratio ($R_{\sigma} =
\sigma_{xy} / \sigma_{xx}^2 H$). The Hall coefficient is seen to satisfy a
scaling equation of the form $R_H = f [H / (a + b T^c)]$. These results are
compared to those observed earlier in CeCoIn$_5$, and are discussed in terms of
the contrasting phase diagram which the CeIrIn$_5$ system exhibits in relation
to its Co counterpart.


title: Test vectors for trilinear forms : the case of two principal series

abstract:
  Let F be a finite extension of Qp and G be GL(2,F). When V is the tensor
product of three admissible, irreducible, finite dimensional representations of
G, the space of G-invariant linear forms has dimension at most one. When a non
zero linear form exists, one wants to find an element of V which is not in its
kernel: this is a test vector. Gross and Prasad found explicit test vectors
when the three representations are unramified principal series, and when they
are all unramified twists of the Steinberg representation. In this paper we
decribe explicit test vectors when two of the representations are principal
series.


title:
A Central Limit Theorem for the SINR at the LMMSE Estimator Output for
  Large Dimensional Signals

abstract:
  This paper is devoted to the performance study of the Linear Minimum Mean
Squared Error estimator for multidimensional signals in the large dimension
regime. Such an estimator is frequently encountered in wireless communications
and in array processing, and the Signal to Interference and Noise Ratio (SINR)
at its output is a popular performance index. The SINR can be modeled as a
random quadratic form which can be studied with the help of large random matrix
theory, if one assumes that the dimension of the received and transmitted
signals go to infinity at the same pace. This paper considers the asymptotic
behavior of the SINR for a wide class of multidimensional signal models that
includes general multi-antenna as well as spread spectrum transmission models.
  The expression of the deterministic approximation of the SINR in the large
dimension regime is recalled and the SINR fluctuations around this
deterministic approximation are studied. These fluctuations are shown to
converge in distribution to the Gaussian law in the large dimension regime, and
their variance is shown to decrease as the inverse of the signal dimension.


title:
On Fick's first law and the equations of quasi-static motion governing
  the molecular diffusion

abstract:
  The problem of the molecular diffusion in a biphasic fluid mixture is studied
here from the two complementary points of view of Continuum Mechanics - in a
somewhat different manner from Truesdell in "Mechanical basis of diffusion" (J.
Chem. Physics (U.S.), 37 (1962) 2336-2344) - and that of Thermodynamics. It is
established that the force involved in the 'diffusive drag', i.e. in the
inter-constituent viscous friction, is necessarily linked to the relative
diffusion velocity of one constituent with respect to the other. We also end up
with Fick's first law, which appears to be a sufficient condition for the
dissipated power associated with the diffusive motions to be positive.


title:
The effect of undrained heating on a fluid-saturated hardened cement
  paste

abstract:
  The effect of undrained heating on volume change and induced pore pressure
increase is an important point to properly understand the behaviour and
evaluate the integrity of an oil well cement sheath submitted to rapid
temperature changes. This thermal pressurization of the pore fluid is due to
the discrepancy between the thermal expansion coefficients of the pore fluid
and of the solid matrix. The equations governing the undrained
thermo-hydro-mechanical response of a porous material are presented and the
effect of undrained heating is studied experimentally for a saturated hardened
cement paste. The measured value of the thermal pressurization coefficient is
equal to 0.6MPa/°C. The drained and undrained thermal expansion
coefficients of the hardened cement paste are also measured in the heating
tests. The anomalous thermal behaviour of cement pore fluid is back analysed
from the results of the undrained heating test.


title:
Comparison of strong coupling regimes in bulk GaAs, GaN and ZnO
  semiconductor microcavities

abstract:
  Wide bandgap semiconductors are attractive candidates for polariton-based
devices operating at room temperature. We present numerical simulations of
reflectivity, transmission and absorption spectra of bulk GaAs, GaN and ZnO
microcavities, in order to compare the particularities of the strong coupling
regime in each system. Indeed the intrinsic properties of the excitons in these
materials result in a different hierarchy of energies between the valence-band
splitting, the effective Rydberg and the Rabi energy, defining the
characteristics of the exciton-polariton states independently of the quality
factor of the cavity. The knowledge of the composition of the polariton
eigenstates is central to optimize such systems. We demonstrate that, in ZnO
bulk microcavities, only the lower polaritons are good eigenstates and all
other resonances are damped, whereas upper polaritons can be properly defined
in GaAs and GaN microcavities.


title:
Magnetotransport in the CeIrIn${_5}$ system: The influence of
  antiferromagnetic fluctuations

abstract:
  We present an overview of magnetotransport measurements on the heavy-fermion
superconductor CeIrIn$_5$. Sensitive measurements of the Hall effect and
magnetoresistance (MR) are used to elucidate the low temperature phase diagram
of this system. The normal-state magnetotransport is highly anomalous, and
experimental signatures of a pseudogap-like precursor state to
superconductivity as well as evidence for two distinct scattering times
governing the Hall effect and the MR are observed. Our observations point out
the influence of antiferromagnetic fluctuations on the magnetotransport in this
class of materials. The implications of these findings, both in the context of
unconventional superconductivity in heavy-fermion systems as well as in
relation to the high temperature superconducting cuprates are discussed.


title:
Implications of Ultra-High-Energy Cosmic Rays for Transient Sources in
  the Auger Era

abstract:
  We study about ultra-high-energy cosmic rays (UHECRs) from transient sources,
propagating in the Galactic and intergalactic space. Based on the recent
observational results, we also estimate upper and lower bounds on the rate of
transient UHECR sources and required isotropic cosmic-ray energy input per
burst as 0.1 Gpc^-3 yr^-1 < rho_0 < 10^3.5 Gpc^-3 yr^-1 and 10^49.5 ergs <
E_HECR^iso < 10^54 ergs, through constraining the apparent burst duration,
i.e., dispersion in arrival times of UHECRs. Based on these bounds, we discuss
implications for proposed candidates such as gamma-ray bursts and active
galactic nuclei.


title:
On systems of Hecke eigenvalues in cohomology of certain subgroups of
  GL_n(F)

abstract:
  We show how there is a natural action on the cohomology groups attached to
certain subgroups of GL_n(F) of the Hecke operators defined as elements in an
adelic double coset algebra.
  Our main result is, that if a system of eigenvalues for Hecke operators occur
in the cohomology groups with coefficients in certain modules, then by changing
the groups the system also occur in the cohomology groups with coefficients in
a 1-dimensional module.


title:
Fourth-Order Perturbation Expansion for Hubbard Model on a
  Two-Dimensional Square Lattice

abstract:
  We investigate the Hubbard model on a two-dimensional square lattice by the
perturbation expansion to the fourth order in the on-site Coulomb repulsion U.
Numerically calculating all diagrams up to the fourth order in self-energy, we
examine the convergence of perturbation series in the lattice system. We
indicate that the coefficient of each order term rapidly decreases as in the
impurity Anderson model for T > 0.1t in the half-filled case, but it holds in
the doped case even at lower temperatures. Thus, we can expect that the
convergence of perturbation expansion in U is very good in a wide parameter
region also in the lattice system, except for T < 0.1t in the half-filled case.
We next calculate the density of states in the fourth-order perturbation. In
the half-filled case, the shape in a moderate correlation regime is quite
different from the three peak structure in the second-order perturbation.
Remarkable upper and lower Hubbard bands locate at w = +(-)U/2, and a pseudogap
appears at the Fermi level w=0. This is considered as the precursor of the
Mott-Hubbard antiferromagnetic structure. In the doped case, quasiparticles
with very heavy mass are formed at the Fermi level. Thus, we conclude that the
fourth-order perturbation theory overall well explain the asymptotic behaviors
in a strong correlation regime.


title:
The problem of analytical calculation of barrier crossing
  characteristics for Levy flights

abstract:
  By using the backward fractional Fokker-Planck equation we investigate the
barrier crossing event in the presence of Levy noise. After shortly review
recent results obtained with different approaches on the time characteristics
of the barrier crossing, we derive a general differential equation useful to
calculate the nonlinear relaxation time. We obtain analytically the nonlinear
relaxation time for free Levy flights and a closed expression in quadrature of
the same characteristics for cubic potential.


title: Holomorphic Functions on Bundles Over Annuli

abstract:
  We consider a family E_m(D,M) of holomorphic bundles constructed as follows:
to any given M in GL_n(Z), we associate a "multiplicative automorphism" f of
(C*)^n. Now let D be a f-invariant Stein Reinhardt domain in (C*)^n. Then
E_m(D,M) is defined as the flat bundle over the annulus of modulus m>0, with
fiber D, and monodromy f. We show that the function theory on E_m(D,M) depends
nontrivially on the parameters m, M and D. Our main result is that
  E_m(D,M) is Stein if and only if m log(r(M)) <= 2 \pi^2, where r(M) denotes
the max of the spectral radii of M and its inverse. As corollaries, we: --
obtain a classification result for Reinhardt domains in all dimensions; --
establish a similarity between two known counterexamples to a question of J.-P.
Serre; -- suggest a potential reformulation of a disproved conjecture of Siu
Y.-T.


title:
Two superconducting gaps in LaFeAsO0.92F0.08 revealed by 75As nuclear
  quadrupole resonance

abstract:
  We report $^{75}$As nuclear quadrupole resonance (NQR) studies on
superconducting oxypnictide LaFeAsO$_{0.92}$F$_{0.08}$ ($T_{\rm c}$ = 23 K).
The temperature dependence of the spin lattice relaxation rate (1/$T_1$)
decreases below $T_{\rm c}$ without a coherence (Hebel-Slichter) peak and shows
a temperature dependence that is not simple power-law nor exponential. We show
that the result can be understood in terms of two superconducting gaps of
either $d$- or ${\pm}s$-wave symmetry, with the larger gap $\Delta_1\sim 4
k_{\rm B}T_{\rm c}$ and the smaller one $\Delta_2 \sim 1.5 k_{\rm B}T_{\rm c}$.
Our result suggests that the multiple-gaps feature is universal in the
oxypnictides superconductors, which is probably associated with the multiple
electronic bands structure in this new class of materials. We also find that
1/$T_1T$ above $T_{\rm c}$ increases with decreasing temperature, which
suggests weak magnetic fluctuations in the normal state.


title:
Non-standard conserved Hamiltonian structures in dissipative/damped
  systems : Nonlinear generalizations of damped harmonic oscillator

abstract:
  In this paper we point out the existence of a remarkable nonlocal
transformation between the damped harmonic oscillator and a modified Emden type
nonlinear oscillator equation with linear forcing, $\ddot{x}+\alpha
x\dot{x}+\beta x^3+\gamma x=0,$ which preserves the form of the time
independent integral, conservative Hamiltonian and the equation of motion.
Generalizing this transformation we prove the existence of non-standard
conservative Hamiltonian structure for a general class of damped nonlinear
oscillators including Li\'enard type systems. Further, using the above
Hamiltonian structure for a specific example namely the generalized modified
Emden equation $\ddot{x}+\alpha x^q\dot{x}+\beta x^{2q+1}=0$, where $\alpha$,
$\beta$ and $q$ are arbitrary parameters, the general solution is obtained
through appropriate canonical transformations. We also present the conservative
Hamiltonian structure of the damped Mathews-Lakshmanan oscillator equation. The
associated Lagrangian description for all the above systems is also briefly
discussed.


title:
Orbital-limiting and modulation induced by missing parity in
  non-centrosymmetric superconductors

abstract:
  We examine the depairing field $H_{c2}(T)$ of non-centrosymmetric
superconductors with a spin-orbit coupling larger than the Zeeman energy at
$H_{c2}(0)$ by taking account of the mixing of spin-singlet and triplet pairing
states due to the missing parity. When the singlet and triplet pairing
components are mixed with an equal weight in a cubic non-centrosymmetric
system, the paramagnetic depairing effect is significantly suppressed so that
$H_{c2}(T)$ approaches its orbital-limited value. A similar event also occurs
in a quasi two-dimensional Rashba non-centrosymmetric system. The present
results are relevant to the $H$-$T$ phase diagrams of CePt$_3$Si and the
families of Li$_2$Pd$_{3-x}$Pt$_x$B.


title:
Dynamics of a Completely Integrable $N$-Coupled Li\'enard Type Nonlinear
  Oscillator

abstract:
  We present a system of $N$-coupled Li\'enard type nonlinear oscillators which
is completely integrable and possesses explicit $N$ time-independent and $N$
time-dependent integrals. In a special case, it becomes maximally
superintegrable and admits $(2N-1)$ time-independent integrals. The results are
illustrated for the N=2 and arbitrary number cases. General explicit periodic
(with frequency independent of amplitude) and quasiperiodic solutions as well
as decaying type/frontlike solutions are presented, depending on the signs and
magnitudes of the system parameters. Though the system is of a nonlinear damped
type, our investigations show that it possesses a Hamiltonian structure and
that under a contact transformation it is transformable to a system of
uncoupled harmonic oscillators.


title: Quantum entanglement at the psi(3770) and Upsilon(4S)

abstract:
  We review results which explicitly depend on the entanglement of neutral
meson pairs produced at the psi(3770) and Upsilon(4S). Time-dependent
CP-violation analyses at the B-factories use the flavour-singlet final state at
the Upsilon(4S), but by assuming its quantum-mechanical evolution; Belle on the
other hand has tested the time-dependent flavour correlation of the B-mesons,
comparing predictions of quantum mechanics, spontaneous disentanglement, and
Pompili-Selleri models. At the psi(3770), decay rates are modulated by various
combinations of the charm mixing parameters: this has been exploited by CLEO-c
to provide the first effective constraint on the strong-phase difference delta.
Finally, the goal of a "model-independent" phi_3/Dalitz analysis is now within
reach, using D-mesons from the psi(3770) to constrain the D0 -> K_S pi+ pi-
decay amplitude. Manifestly entangled events psi(3770) -> (K_S pi+pi-)_D (K_S
pi+ pi-)_D, rather than just "CP-tagged" decays, turn out to be crucial.


title:
Split decomposition and graph-labelled trees: characterizations and
  fully-dynamic algorithms for totally decomposable graphs

abstract:
  In this paper, we revisit the split decomposition of graphs and give new
combinatorial and algorithmic results for the class of totally decomposable
graphs, also known as the distance hereditary graphs, and for two non-trivial
subclasses, namely the cographs and the 3-leaf power graphs. Precisely, we give
strutural and incremental characterizations, leading to optimal fully-dynamic
recognition algorithms for vertex and edge modifications, for each of these
classes. These results rely on a new framework to represent the split
decomposition, namely the graph-labelled trees, which also captures the modular
decomposition of graphs and thereby unify these two decompositions techniques.
The point of the paper is to use bijections between these graph classes and
trees whose nodes are labelled by cliques and stars. Doing so, we are also able
to derive an intersection model for distance hereditary graphs, which answers
an open problem.


title: Rough Volterra equations 2: convolutional generalized integrals

abstract:
  We define and solve Volterra equations driven by an irregular signal, by
means of a variant of the rough path theory allowing to handle generalized
integrals weighted by an exponential coefficient. The results are applied to
the fractional Brownian motion with Hurst coefficient greater than 1/3


title: Hydrodynamic View of Wave-Packet Interference: Quantum Caves

abstract:
  Wave-packet interference is investigated within the complex quantum
Hamilton-Jacobi formalism using a hydrodynamic description. Quantum
interference leads to the formation of the topological structure of quantum
caves in space-time Argand plots. These caves consist of the vortical and
stagnation tubes originating from the isosurfaces of the amplitude of the wave
function and its first derivative. Complex quantum trajectories display
counterclockwise helical wrapping around the stagnation tubes and hyperbolic
deflection near the vortical tubes. The string of alternating stagnation and
vortical tubes is sufficient to generate divergent trajectories. Moreover, the
average wrapping time for trajectories and the rotational rate of the nodal
line in the complex plane can be used to define the lifetime for interference
features.


title: Two-bath model for activated surface diffusion of interacting adsorbates

abstract:
  The diffusion and low vibrational motions of adsorbates on surfaces can be
well described by a purely stochastic model, the so-called interacting single
adsorbate model, for low-moderate coverages (\theta \lesssim 0.12). Within this
model, the effects of thermal surface phonons and adsorbate-adsorbate
collisions are accounted for by two uncorrelated noise functions which arise in
a natural way from a two-bath model based on a generalization of the one-bath
Caldeira-Leggett Hamiltonian. As an illustration, the model is applied to the
diffusion of Na atoms on a Cu(001) surface with different coverages.


title: Bose Einstein condensation in a gas of the Fibonacci oscillators

abstract:
  We consider a system of the two-parameter deformed boson oscillators whose
spectrum is given by a generalized Fibonacci sequence. In order to obtain the
role of the deformation parameters (q1,q2) on the thermostatistics of the
system, we calculate several thermostatistical functions in the thermodynamical
limit and investigate the low-temperature behavior of the system. In this
framework, we show that the thermostatistics of the (q1,q2)-bosons can be
studied by the formalism of Fibonacci calculus which generalizes the recently
proposed formalism of q-calculus. We also discuss the conditions under which
the Bose-Einstein condensation would occur in the present two-parameter
generalized boson gas. However, the ordinary boson gas results can be obtained
by applying the limit q1=q2=1.


title:
Pseudogap and Superconductivity in Iron-Based Layered Superconductor
  studied by Fluctuation-Exchange Approximation

abstract:
  We investigate interplay between magnetic fluctuations and superconductivity
in the effective five-band Hubbard model for iron-oxypnictide superconductors
on the basis of the fluctuation-exchange approximation. As for the normal-state
properties, we find the pseudogap behavior in the NMR relaxation rate and the
spectral weight in the electron-doped region, while we cannot find such
behavior in the hole-doped region. The pseudogap behavior originates from the
band structure effect, that is, existence of high density of states just below
the Fermi level.
  Solving the superconducting Eliashberg equation, we find that the most
probable candidate for the pairing symmetry is the sign-changed s-wave
spin-singlet state. For small Hund's coupling J, the eigenvalue is not so
sensitive to carrier doping, and seems to be irrelevant with antiferromagnetic
(AF) spin fluctuation. We suggest that correlation between spin and
spin-quadrupole is important as the pairing mechanism as well as the AF
fluctuation.


title:
Representation of solutions of the Gauss hypergeometric equation by the
  multiple polylogarithms, functional relations of the multiple polylogarithms
  and relations of the multiple zeta values

abstract:
  In this article, we express solutions of the Gauss hypergeometric equation as
a series of the multiple polylogarithms by using iterated integral. This
representation is the most simple case of a semisimple representation of
solutions of the formal KZ equation. Moreover, combining this representation
with the connection relations of solutions of the Gauss hypergeometric
equation, we obtain various relations of the multiple polylogarithms of one
variable and the multiple zeta values.


title: Thermal transport in isotopically disordered carbon nanotubes

abstract:
  We present a study of the phononic thermal conductivity of isotopically
disordered carbon nanotubes. In particular, the behavior of the thermal
conductivity as a function of the system length is investigated, using Green's
function techniques to compute the transmission across the system. The method
is implemented using linear scaling algorithms, which allows us to reach
systems of lengths up to $L=2.5\mu$m (with up to 400,000 atoms). As for 1D
systems, it is observed that the conductivity diverges with the system size
$L$. We also observe a dramatic decrease of the thermal conductance for systems
of experimental sizes (roughly 80% at room temperature for $L = 2.5$ $\mu$m),
when a large fraction of isotopic disorder is introduced. The results obtained
with Green's function techniques are compared to results obtained with a
Boltzmann description of thermal transport. There is a good agreement between
both approaches for systems of experimental sizes, even in presence of Anderson
localization. This is particularly interesting since the computation of the
transmission using Boltzmann's equation is much less computationally expensive,
so that larger systems may be studied with this method.


title:
Quantum Ratchets on Maximally Uniform States in Phase Space:
  Semiclassical Full-Chaos Regime

abstract:
  A generic kind of quantum chaotic ratchet is introduced, based on initial
states that are \emph{uniform} in phase space with the \emph{maximal possible}
resolution of one Planck cell. Unlike a classical phase-space uniform density,
such a state usually carries a \emph{nonzero} ratchet current, even in
\emph{symmetric} systems. This quantum ratchet effect basically emerges from
the generic asymmetry of the state quasicoordinates in the Planck cell. It is
shown, on the basis of exact results, general arguments, and extensive
numerical evidence, that in a semiclassical full-chaos regime the variance of
the current over all the states is nearly proportional to the chaotic-diffusion
rate and to the square of the scaled Planck constant. Experimental realizations
are suggested.


title: Properties of $Q\bar Q$ mesons in non-relativistic QCD formalism

abstract:
  The decay rates of $Q \bar Q$ mesons ($Q \varepsilon {c, b}$) are studied in
the NRQCD formalism in terms of their short distance and long distance
coefficients. The long distance coefficients are obtained through
phenomenological potential model description of the mesons. The model
parameters that reproduces the mass spectrum of the $c \bar c$, $b \bar b$ and
$c \bar b$ mesons are employed to study the decay widths of these mesons. We
extract the mass spectrum as well as the reproduces the respective radial wave
functions from the different potential models as well as from non-relativistic
phenomenological quark antiquark potential of the type
$V(r)=-\frac{\alpha_c}{r}+A r^{\nu}$, with $\nu$ varying from 0.5 to 2. The
spin hyperfine and spin-orbit interactions are employed to obtain the masses of
the pseudoscalar and vector mesons. The decay constants with QCD corrections
are computed in this model as well as in the case of other potential models for
comparison. The digamma and dileptonic decays of $c \bar c$, and $b \bar b$
mesons are investigated using some of the known potential models without and
with radiative corrections up to the lowest order. These decay width are also
computed within the NRQCD formalism up to $O(v^4)$ by making uses of the
respective spectroscopic parameters of the models. Our theoretical predictions
of the decays of the $c \bar c$, and $b \bar b$ mesons and the results obtained
from some of the other potential schemes are compared with the experimental
values. The partial widths and life time of the $B_c$ meson are also computed
using the model parameters and are found to be in good accordance with the
experimental values.


title:
Sensitivity of protein rigidity analysis to small structural variations:
  a large-scale comparative analysis

abstract:
  Rigidity analysis using the "pebble game" can usefully be applied to protein
crystal structures to obtain information on protein folding, assembly and the
structure-function relationship. However, previous work using this technique
has not made clear how sensitive rigidity analysis is to small structural
variations. We present a comparative study in which rigidity analysis is
applied to multiple structures, derived from different organisms and different
conditions of crystallisation, for each of several different proteins. We find
that rigidity analysis is best used as a comparative tool to highlight the
effects of structural variation. Our use of multiple protein structures brings
out a previously unnoticed peculiarity in the rigidity of trypsin.


title:
Interrelationship Between Protein Electrostatics and Evolution in HCV
  and HIV Replicative Proteins

abstract:
  Protein electrostatics have been demonstrated to play a vital role in protein
functionality, with many functionally important amino acid residues exhibiting
an electrostatic state that is altered from that of a normal amino acid
residue. Residues with altered electrostatic states can be identified by the
presence of a pKa value that is perturbed by 2 or more pK units, and such
residues have been demonstrated to play critical roles in catalysis, ligand
binding, and protein stability. Within the HCV helicase and polymerase, as well
as the HIV reverse transcriptase, highly conserved regions were demonstrated to
possess a greater number and magnitude of perturbations than lesser conserved
regions, suggesting that there is an interrelationship present between protein
electrostatics and evolution.


title: VERITAS Distant Laser Calibration and Atmospheric Monitoring

abstract:
  As a calibrated laser pulse propagates through the atmosphere, the intensity
of the Rayleigh scattered light arriving at the VERITAS telescopes can be
calculated precisely. This allows for absolute calibration of imaging
atmospheric Cherenkov telescopes (IACT) to be simple and straightforward. In
these proceedings, we present the comparison between laser data and simulation
to estimate the light collection efficiencies of the VERITAS telescopes, and
the analysis of multiple laser data sets taken in different months for
atmospheric monitoring purpose.


title: Further X-ray detections of Herbig stars

abstract:
  The interpretation of X-ray detections from Herbig Ae/Be stars is disputed as
it is not clear if these intermediate-mass pre-main sequence stars are able to
drive a dynamo and ensuing phenomena of magnetic activity. Alternative X-ray
production mechanisms, related to stellar winds, star-disk magnetospheres, or
unresolved late-type T Tauri star companions have been proposed. In a series of
papers we have been investigating high-resolution X-ray Chandra images of
Herbig Ae/Be and main-sequence B-type stars to test the T Tauri hypothesis by
spatially resolving known visual companions from the primaries. Here we report
on six as yet unpublished Chandra exposures from our X-ray survey of Herbig
stars. The target list comprises six Herbig stars with known cool companions,
and three further A/B-type stars that are serendipitously in the Chandra
field-of-view. In this sample we record a detection rate of 100%, i.e. all
A/B-type stars display X-ray emission at levels of log(L_x/L_bol) ~ -5...-7.
The analysis of hardness ratios confirms that HAeBe's have hotter and/or more
absorbed X-ray emitting plasma than more evolved B-type stars. Radiative winds
are ruled out as exclusive emission mechanism on basis of the high X-ray
temperatures. Confirming earlier results, the X-ray properties of Herbig Ae/Be
stars are not vastly different from those of their late-type companion stars
(if such are known). The diagnostics provided by the presently available data
leave open if the hard X-ray emission of Herbig stars is due to young age or
indicative of further coronally active low-mass companion stars. In the latter
case, our detection statistics imply a high fraction of higher-order multiple
systems among Herbig stars.


title: The role of lubricant molecular shape in microscopic friction

abstract:
  With the help of a simple two-dimensional model we simulate the tribological
properties of a thin lubricant film consisting of linear (chain) molecules in
the ordinary soft-lubricant regime. We find that friction generally increases
with chain length, in agreement with their larger bulk viscosity. When
comparing the tribological properties of molecules which stick bodily to the
substrates with others carrying a single sticking termination, we find that the
latter generally yield a larger friction than the former.


title:
Beyond ideal MHD: towards a more realistic modeling of relativistic
  astrophysical plasmas

abstract:
  Many astrophysical processes involving magnetic fields and quasi-stationary
processes are well described when assuming the fluid as a perfect conductor.
For these systems, the ideal-magnetohydrodynamics (MHD) description captures
the dynamics effectively and a number of well-tested techniques exist for its
numerical solution. Yet, there are several astrophysical processes involving
magnetic fields which are highly dynamical and for which resistive effects can
play an important role. The numerical modeling of such non-ideal MHD flows is
significantly more challenging as the resistivity is expected to change of
several orders of magnitude across the flow and the equations are then either
of hyperbolic-parabolic nature or hyperbolic with stiff terms. We here present
a novel approach for the solution of these relativistic resistive MHD equations
exploiting the properties of implicit-explicit (IMEX) Runge Kutta methods. By
examining a number of tests we illustrate the accuracy of our approach under a
variety of conditions and highlight its robustness when compared with
alternative methods, such as the Strang-splitting. Most importantly, we show
that our approach allows one to treat, within a unified framework, both those
regions of the flow which are fluid-pressure dominated (such as in the interior
of compact objects) and those which are instead magnetic-pressure dominated
(such as in their magnetospheres)


title: Global entanglement and coherent states in an N-partite system

abstract:
  We consider a quantum system consisting of N parts, each of which is a
"quKit" described by a K dimensional Hilbert space. We prove that in the
symmetric subspace, S, a pure state is not globally entangled, if and only if
it is a coherent state. It is also shown that in the orthogonal complement all
states are globally entangled.


title: A basic set for the alternating group

abstract:
  This article concerns the $p$-basic set existence problem in the
representation theory of finite groups. We show that, for any odd prime $p$,
the alternating group $\A_n$ has a $p$-basic set. More precisely, we prove that
the symmetric group $\sym_n$ has a $p$-basic set with some additional
properties, allowing us to deduce a $p$-basic set for $\A_n$. Our main tool is
the generalized perfect isometries introduced by K\"ulshammer, Olsson and
Robinson. As a consequence we obtain some results on the decomposition number
of $\A_n$.


title:
Neutral Kaon Mixing Beyond the Standard Model from 2+1 Flavour Domain
  Wall QCD

abstract:
  We present preliminary results of a study of Delta S = 2 matrix elements
originating from physics beyond the Standard Model. Using 2+1 flavour Domain
Wall Fermions we obtain the non-perturbative renormalisation (mixing) matrix in
the RI scheme. We also discuss plans for the chiral extrapolation of the
renormalised matrix elements in a partially quenched set-up.


title: Design and construction of the Mini-Calorimeter of the AGILE satellite

abstract:
  AGILE is a small space mission of the Italian Space Agency (ASI) devoted to
gamma-ray and hard-X astrophysics, successfully launched on April 23 2007. The
AGILE Payload is composed of three instruments: a gamma-ray imager based on a
tungsten-silicon tracker (ST), for observations in the gamma ray energy range
30MeV - 50GeV, a Silicon based X-ray detector, SuperAGILE (SA), for imaging in
the range 18keV - 60keV and a CsI(Tl) Mini-Calorimeter (MCAL) that detects
gamma rays or charged particles energy loss in the range 300keV - 100MeV. MCAL
is composed of 30 CsI(Tl) scintillator bars with photodiode readout at both
ends, arranged in two orthogonal layers. MCAL can work both as a slave of the
ST and as an independent gamma-ray detector for transients and gamma-ray bursts
detection. In this paper a detailed description of MCAL is presented together
with its performance.


title: The static-light meson spectrum from twisted mass lattice QCD

abstract:
  We compute the static-light meson spectrum with N_f = 2 flavours of sea
quarks using Wilson twisted mass lattice QCD. We consider five different values
for the light quark mass corresponding to 300 MeV < m_PS < 600 MeV and we
present results for angular momentum j = 1/2, j = 3/2 and j = 5/2 and for
parity P = + and P = -. We extrapolate our results to physical quark masses and
make predictions regarding the spectrum of B and B_s mesons.


title: INTEGRAL/IBIS and Swift/XRT observations of hard cataclysmic variables

abstract:
  The analysis of the third INTEGRAL/IBIS survey has revealed several new
cataclysmic variables, most of which turned out to be intermediate polars, thus
confirming that these objects are strong emitters in hard X-rays. Here we
present high energy spectra of all 22 cataclysmic variables detected in the 3rd
IBIS survey and provide the first average spectrum over the 20-100 keV band for
this class. Our analysis indicates that the best-fit model is a thermal
bremsstrahlung with an average temperature of <kT> ~22 keV. Recently, eleven
(ten intermediate polars and one polar) of these systems have been followed-up
by Swift/XRT (operating in the 0.3-10 keV energy band), thus allowing us to
investigate their spectral behaviour over the range ~0.3-100 keV. Thanks to
this wide energy coverage, it was possible for these sources to simultaneously
measure the soft and hard components and estimate their temperatures. The soft
emission, thought to originate in the irradiated poles of the white dwarf
atmosphere, is well described by a blackbody model with temperatures in the
range ~60-120 eV. The hard emission, which is supposed to be originated from
optically thin plasma in the post-shock region above the magnetic poles, is
indeed well modelled with a bremsstrahlung model with temperatures in the range
~16-33 keV, similar to the values obtained from the INTEGRAL data alone. In
several cases we also find the presence of a complex absorber: one totally
(with NH ~(0.4-28) x 10^{21} cm^{-2}) and one partially (with NH ~(0.7-9) x
10^{23} cm^{-2}) covering the source. Only in four cases (V709 Cas, GK Per, IGR
J06253+7334 and IGR J17303-0601), we find evidence for the presence of an iron
line at 6.4 keV. We discuss our findings in the light of the systems parameters
and cataclysmic variables/intermediate polars modelling scenario.


title: Precision $B_c$ and $B_s$ mass calculations

abstract:
  We give improved results for B meson masses using NRQCD $b$ quarks and HISQ
light valence quarks for a range of lattice spacings and sea quark masses
enabling controlled extrapolation to the physical point.


title:
Calculation of Anderson localization criterium for a one dimensional
  chain with diagonal disorder

abstract:
  For a one dimensional half-infinite chain with diagonal disorder we
calculated the ultimate at $t\to\infty$ value of the average excitation density
at the edge site $D$ if at $t=0$ the excitation was localised at the edge site
(Anderson' s creterium). We obtained the following results: i) for the binary
disordered chain we derived the close expression for $D$ which is exact in the
limit of low concentration of defects and is valid for an arbitrary energy of
defects $\varepsilon$. In this case $D$ demonstrated the non analytical
dependence on $\varepsilon$. ii) The close expression for $D$ is obtained for
the case of an arbitrary small disorder. iii) The relative contribution of
states with specified energy to $D$ is calculated. All the results obtained are
in complete agreement with computer simulation.