title: Spectroscopic Observations of the Mass Donor Star in SS 433

abstract:
  The microquasar SS 433 is an interacting massive binary consisting of an
evolved mass donor and a compact companion that ejects relativistic jets. The
mass donor was previously identified through spectroscopic observations of
absorption lines in the blue part of the spectrum that showed Doppler shifts
associated with orbital motion and strength variations related to the orbital
modulation of the star-to-disk flux ratio and to disk obscuration. However,
subsequent observations revealed other absorption features that lacked these
properties and that were probably formed in the disk gas outflow. We present
here follow-up observations of SS 433 at orbital and precession phases
identical to those from several previous studies with the goals of confirming
the detection of the mass donor spectrum and providing more reliable masses for
the two system components. We show that the absorption features present as well
as those previously observed almost certainly belong to the mass donor star,
and we find revised masses of 12.3 +/- 3.3 and 4.3 +/- 0.8 M(sun) for the mass
donor and compact object, respectively.


title:
Vertical Shearing Instabilities in Radially Shearing Disks: The Dustiest
  Layers of the Protoplanetary Nebula

abstract:
  Gravitational instability of a vertically thin, dusty sheet near the midplane
of a protoplanetary disk has long been proposed as a way of forming
planetesimals. Before Roche densities can be achieved, however, the dust-rich
layer, sandwiched from above and below by more slowly rotating dust-poor gas,
threatens to overturn and mix by the Kelvin-Helmholtz instability (KHI).
Whether such a threat is real has never been demonstrated: the Richardson
criterion for the KHI is derived for 2-D Cartesian shear flow and does not
account for rotational forces. Here we present 3-D numerical simulations of
gas-dust mixtures in a shearing box, accounting for the full suite of
disk-related forces: the Coriolis and centrifugal forces, and radial tidal
gravity. Dust particles are assumed small enough to be perfectly entrained in
gas; the two fluids share the same velocity field but obey separate continuity
equations. We find that the Richardson number Ri does not alone determine
stability. The critical value of Ri below which the dust layer overturns and
mixes depends on the height-integrated metallicity Z (surface density ratio of
dust to gas). Nevertheless, for Z between one and five times solar, the
critical Ri is nearly constant at 0.1. Keplerian radial shear stabilizes those
modes that would otherwise disrupt the layer at large Ri. If Z is at least 5
times greater than the solar value of 0.01, then midplane dust densities can
approach Roche densities. Such an environment might be expected to produce gas
giant planets having similarly super-solar metallicities.


title: Kondo Effect in Spin Chains

abstract:
  The free electron Kondo problem can be described by a one-dimensional (1D)
model because only the s-wave part of the electronic wave-function is affected
by the Kondo coupling. Since only the spin degrees of freedom are involved in
the Kondo interaction, and due to spin-charge separation in 1D, the universal
low energy long distance physics of the Kondo model also arises when a magnetic
impurity is coupled to the end of a gap-less antiferromagnetic J_1-J_2 spin-1/2
chain, where J_1(J_2) is the (next-)nearest neighbor coupling. Experimental
realizations of such spin chain models are possible and using various
analytical and numerical techniques, we present a detailed and quantitative
comparison between the usual free electron Kondo model and such spin chain
versions of the Kondo problem. For the gap-less J_1-J_2 spin chain two cases
are studied, with zero next nearest neighbor coupling, J_2=0, and with a
critical second neighbor coupling, J_2=J_2c. We first focus on the spin chain
impurity model at J_2c~0.2412 where a bulk marginal coupling present in the
spin chain model for J_2<J_2c vanishes. At J_2c, the usual Kondo physics is
recovered in the spin chain model in the low energy regime. We then analyze the
nearest-neighbor model (J_2=0) where a new kind of Kondo effect occurs due to
the presence of the bulk marginal coupling. This marginal coupling leads to a
slower variation of the Kondo temperature T_K with the bare Kondo coupling. In
the exact Bethe ansatz solution of this spin chain impurity model (J_2=0) Frahm
and Zvyagin noted this relation as well as the connection to the Kondo problem.
Here, we provide further evidence for the connection to Kondo physics and
present low temperature QMC results for the impurity susceptibility that
further support this connection.


title:
The M33 Metallicity Project: Resolving the Abundance Gradient
  Discrepancies in M33

abstract:
  We present a new determination of the metallicity gradient in M33, based on
Keck/LRIS measurements of oxygen abundances using the temperature-sensitive
emission line [OIII] 4363 A in 61 HII regions. These data approximately triple
the sample of direct oxygen abundances in M33. We find a central abundance of
12 + log(O/H) = 8.36+/-0.04 and a slope of -0.027+/-0.012 dex/kpc, in agreement
with infrared measurements of the neon abundance gradient but much shallower
than most previous oxygen gradient measurements. There is substantial intrinsic
scatter of 0.11 dex in the metallicity at any given radius in M33, which
imposes a fundamental limit on the accuracy of gradient measurements that rely
on small samples of objects. We also show that the ionization state of neon
does not follow the ionization state of oxygen as is commonly assumed,
suggesting that neon abundance measurements from optical emission lines require
careful treatment of the ionization corrections.


title:
Methods for Rapidly Processing Angular Masks of Next-Generation Galaxy
  Surveys

abstract:
  As galaxy surveys become larger and more complex, keeping track of the
completeness, magnitude limit, and other survey parameters as a function of
direction on the sky becomes an increasingly challenging computational task.
For example, typical angular masks of the Sloan Digital Sky Survey contain
about N=300,000 distinct spherical polygons. Managing masks with such large
numbers of polygons becomes intractably slow, particularly for tasks that run
in time O(N^2) with a naive algorithm, such as finding which polygons overlap
each other. Here we present a "divide-and-conquer" solution to this challenge:
we first split the angular mask into predefined regions called "pixels," such
that each polygon is in only one pixel, and then perform further computations,
such as checking for overlap, on the polygons within each pixel separately.
This reduces O(N^2) tasks to O(N), and also reduces the important task of
determining in which polygon(s) a point on the sky lies from O(N) to O(1),
resulting in significant computational speedup. Additionally, we present a
method to efficiently convert any angular mask to and from the popular HEALPix
format. This method can be generically applied to convert to and from any
desired spherical pixelization. We have implemented these techniques in a new
version of the mangle software package, which is freely available at
http://space.mit.edu/home/tegmark/mangle/, along with complete documentation
and example applications. These new methods should prove quite useful to the
astronomical community, and since mangle is a generic tool for managing angular
masks on a sphere, it has the potential to benefit terrestrial mapmaking
applications as well.


title: Experimental constraints on fourth generation quark masses

abstract:
  The existing bounds from CDF on the masses of the fourth generation quarks,
t' and b', are reexamined. The bound of 256 GeV on the t' mass assumes that the
primary decay of the t' is into q+W, which is not the case for a substantial
region of parameter space. The bound of 268 GeV on the b' mass assumes that the
branching ratio for b' --> b+Z is very large, which is not only not true for
much of parameter space, but is {\em never} true for b' masses above 255 GeV.
In addition, it is assumed that the heavy quarks decay within the silicon
vertex detector, and for small mixing angles this will not be the case. The
experimental bounds, including all of these effects, are found as a function of
the other heavy quark mass and the mixing angle.


title: Complete Six-Gluon Disk Amplitude in Superstring Theory

abstract:
  We evaluate all next-to-maximal helicity violating (NMHV) six-gluon
amplitudes in type I open superstring theory in four dimensions, at the disk
level, to all orders in alpha'. Although the computation utilizes
supersymmetric Ward identities, the result holds for all compactifications,
even for those that break supersymmetry and is completely model-independent.
Together with the maximally helicity violating (MHV) amplitudes presented in
the previous work, our results provide the complete six-gluon disk amplitude.


title: Kinetic Simulations of Magnetized Turbulence in Astrophysical Plasmas

abstract:
  This letter presents the first ab initio, fully electromagnetic, kinetic
simulations of magnetized turbulence in a homogeneous, weakly collisional
plasma at the scale of the ion Larmor radius (ion gyroscale). Magnetic and
electric-field energy spectra show a break at the ion gyroscale; the spectral
slopes are consistent with scaling predictions for critically balanced
turbulence of Alfven waves above the ion gyroscale (spectral index -5/3) and of
kinetic Alfven waves below the ion gyroscale (spectral indices of -7/3 for
magnetic and -1/3 for electric fluctuations). This behavior is also
qualitatively consistent with in situ measurements of turbulence in the solar
wind. Our findings support the hypothesis that the frequencies of turbulent
fluctuations in the solar wind remain well below the ion cyclotron frequency
both above and below the ion gyroscale.


title:
Transformations between 2MASS, SDSS and BVRI photometric systems:
  bridging the near infrared and optical

abstract:
  We present colour transformations for the conversion of the {\em 2MASS}
photometric system to the Johnson-Cousins $UBVRI$ system and further into the
{\em SDSS} $ugriz$ system. We have taken {\em SDSS} $gri$ magnitudes of stars
measured with the 2.5-m telescope from $SDSS$ Data Release 5 (DR5), and $BVRI$
and $JHK_{s}$ magnitudes from Stetson's catalogue and \citet{Cu03},
respectively. We matched thousands of stars in the three photometric systems by
their coordinates and obtained a homogeneous sample of 825 stars by the
following constraints, which are not used in previous transformations: 1) the
data are de-reddened, 2) giants are omitted, and 3) the sample stars selected
are of the highest quality. We give metallicity, population type, and
transformations dependent on two colours. The transformations provide absolute
magnitude and distance determinations which can be used in space density
evaluations at short distances where some or all of the {\em SDSS} $ugriz$
magnitudes are saturated. The combination of these densities with those
evaluated at larger distances using {\em SDSS} $ugriz$ photometry will supply
accurate Galactic model parameters, particularly the local space densities for
each population.


title: A note on the \alpha-invariant of the Mukai-Umemura 3-fold

abstract:
  We give an elementary argument to compute the $\alpha$-invariant of this Fano
3-fold, which implies the existence of a Kahler-Einstein metric.


title: Inertial range turbulence in kinetic plasmas

abstract:
  The transfer of turbulent energy through an inertial range from the driving
scale to dissipative scales in a kinetic plasma followed by the conversion of
this energy into heat is a fundamental plasma physics process. A theoretical
foundation for the study of this process is constructed, but the details of the
kinetic cascade are not well understood. Several important properties are
identified: (a) the conservation of a generalized energy by the cascade; (b)
the need for collisions to increase entropy and realize irreversible plasma
heating; and (c) the key role played by the entropy cascade--a dual cascade of
energy to small scales in both physical and velocity space--to convert
ultimately the turbulent energy into heat. A strategy for nonlinear numerical
simulations of kinetic turbulence is outlined. Initial numerical results are
consistent with the operation of the entropy cascade. Inertial range turbulence
arises in a broad range of space and astrophysical plasmas and may play an
important role in the thermalization of fusion energy in burning plasmas.


title:
Hubble-type outflows of the high-excitation, poly-polar planetary nebula
  NGC 6302 -- from expansion proper motions

abstract:
  The ouflowing proper motions of fifteen knots in the dominant northwestern
lobe of the high-excitation poly-polar planetary nebula NGC 6302 have been
determined by comparing their positions relative to those of faint stars in an
image taken at the San Pedro Martir Observatory in 2007 to those in a South
African Astronomical Observatory archival plate obtained by Evans in 1956. The
Hubble-type expansion of this lobe is now directly confirmed in a model
independent way from these measurements. Furthermore, an unambiguous distance
to NGC 6302 of 1.17 +/- 0.14 kpc is now determined. Also all the velocity
vectors of the fifteen knots (and two others) point back to the central source.
An eruptive event from within the central torus, approximately 2200 years
previously must have created the high speed lobes of NGC 6302.


title: Two Higgs Models for Large Tan Beta and Heavy Second Higgs

abstract:
  We study two Higgs models for large $\tan\beta$ and relatively large second
Higgs mass. In this limit the second heavy Higgs should have small vev and
therefore couples only weakly to two gauge bosons. Furthermore, the couplings
to down type quarks can be significantly modified (so long as the second Higgs
is not overly heavy). Both these facts have significant implications for search
strategies at the LHC and ILC. We show how an effective theory and explicit
fundamental two Higgs model approach are related and consider the additional
constraints in the presence of supersymmetry or $Z_2$ flavor symmetries. We
argue that the best tests of the two Higgs doublet potential are likely to be
measurements of the light Higgs branching fractions. We show how higher
dimension operators that have recently been suggested to raise the light Higgs
mass are probably best measured and distinguished in this way.


title:
Panchromatic Spectral Energy Distributions of Dusty Galaxies with
  RADISHE. I. Predictions for Herschel: Correlating Colors with Galactic Energy
  Sources

abstract:
  We present three-dimensional, self-consistent radiative transfer solutions
with a new Monte Carlo radiative equilibrium code. The code, RADISHE
($\bf{RAD}$iative transfer $\bf{I}$n $\bf{S}$moothed particle
$\bf{H}$ydrodynamics and $\bf{E}$ulerian codes), can be applied to calculate
the emergent spectral energy distributions (SEDs) and broadband images from
optical to millimeter wavelengths of arbitrary density geometries with
distributed sources of radiation. One of the primary uses of this code has been
to interface with hydrodynamical codes to calculate emergent SEDs along a
simulation time sequence. The primary methodological focus of this paper is on
the radiative equilibrium temperature calculation. We find that an iterative
calculation of the temperature, which takes as the Monte Carlo estimator for
the mean free intensity the sum of photon flight paths, is significantly faster
than relaxation temperature calculation methods, particularly when large
numbers of grid cells are required, i.e., in modeling three-dimensional
geometries such as the dust envelopes of turbulent massive protostellar cores
or infrared bright galaxies. We present simulated color-color plots for
infrared bright galaxies at a range of redshifts, and unfold these plots as
color vs the fractional AGN luminosity, to demonstrate that $\it{Herschel}$
will be able to effectively discriminate between submillimeter galaxies where
the energy source is dominated by AGN and those where star formation dominates.
[abridged]


title:
A six-dimensional H2-H2 potential energy surface for bound state
  spectroscopy

abstract:
  We present a six-dimensional potential energy surface for the H2-H2 dimer
based on ab initio electronic structure calculations. The surface is intended
to describe accurately the bound and quasibound states of the dimers H2-H2,
D2-D2, and H2-D2 that correlate with H2 or D2 monomers in the rovibrational
levels (v, j) = (0, 0), (0, 2), (1, 0), and (1, 2). We use four experimentally
measured transition energies for these dimers to make two empirical adjustments
to the ab initio surface; the adjusted surface gives computed transition
energies for 56 experimentally observed transitions that agree with experiment
to within 0.036 cm^{-1}. For 29 of the 56 transitions, the agreement between
the computed and measured transition energies is within the quoted experimental
uncertainty. We use our potential energy surface to predict the energies of
another 34 not-yet-observed infrared and Raman transitions for the three
dimers.


title: Blue Compact Dwarf Galaxies with Spitzer: The Infrared/Radio Properties

abstract:
  We study the correlation between the radio, mid-infrared and far-infrared
properties for a sample of 28 blue compact dwarf (BCD) and low metallicity
star-forming galaxies observed by Spitzer. We find that these sources extend
the same far-infrared to radio correlation typical of star forming late type
alaxies to lower luminosities. In BCDs, the 24um (or 22um) mid-infrared to
radio correlation is similar to starburst galaxies, though there is somewhat
larger dispersion in their q_24 parameter compared to their q_FIR. No strong
correlations between the q parameter and galaxy metallicity or effective dust
temperature have been detected, though there is a hint of decreasing q_24 at
low metallicities. The two lowest metallicity dwarfs in our sample, IZw18 and
SBS0335-052E, despite their similar chemical abundance, deviate from the
average q$_{24}$ ratio in opposite manners, displaying an apparent radio excess
and dust excess respectively.


title: A parametrization of the baryon octet and decuplet masses

abstract:
  We construct a general parametrization of the baryon octet and decuplet mass
operators including the three-body terms using the unit operator and the
symmetry-breaking factors $M^d=\textrm{diag} (0,1,0)$ and $M^s=\textrm{diag}
(0,0,1)$ in conjunction with the spin operators. Our parametrization has the
minimal number of operators needed to describe all the octet and decuplet
masses. Investigating the likely size of the three-body terms, we find that
contributions of the three-body hypercharge splittings are comparable to those
from the one- and two-body isospin splittings and that contributions of the
three-body isospin splitting operators are very small. We prove that, in
dynamical calculations, one must go to three loops to get the three-body terms.
We also find that the suggested hierarchy of sizes for terms in the most
general expression for baryon masses that involve multiple factors of $M^d$
and/or $M^s$ does not hold strictly for dynamical calculations in heavy baryon
chiral perturbation theory: terms of a given order in a meson loop expansion
may appear both with the expected factors of $M^d$ and $M^s$, and with one
factor more.


title:
Coherent Control of Ultra-High Frequency Acoustic Resonances in Photonic
  Crystal Fibers

abstract:
  Ultra-high frequency acoustic resonances ($\backsim$2 GHz) trapped within the
glass core ($\backsim$1 $\mu$m diameter) of a photonic crystal fiber are
selectively excited through electrostriction using laser pulses of duration 100
ps and energy 500 pJ. Using precisely timed sequences of such driving pulses,
we achieve coherent control of the acoustic resonances by constructive or
destructive interference, demonstrating both enhancement and suppression of the
vibrations. A sequence of 27 resonantly-timed pulses provides a 100-fold
increase in the amplitude of the vibrational mode. The results are explained
and interpreted using a semi-analytical theory, and supported by precise
numerical simulations of the complex light-matter interaction.


title:
A characterization of two classes of locally truncated diagram
  geometries

abstract:
  We study locally truncated geometries that are parapolar spaces locally of
type A_{n-1,j}(K) with n>6 and j=3,4. Residually connected sheaves over these
geometries are constructed. It is proved that these geometries are residually
connected diagram geometries whose universal 2-covers are truncations of
buildings.


title:
Retired A Stars and Their Companions II: Jovian planets orbiting kappa
  Coronae Borealis and HD167042

abstract:
  We report precise Doppler measurements of two evolved stars, kappa CrB
(HD142091) and HD 167042, obtained at Lick Observatory as part of our search
for planets orbiting intermediate-mass subgiants. Periodic variations in the
radial velocities of both stars reveal the presence of substellar orbital
companions. These two stars are notably massive with stellar masses of 1.80
Msun and 1.64 Msun, indicating that they are former A-type dwarfs that have
evolved off of the main sequence and are now K-type subgiants. The planet
orbiting kappa CrB has a minimum mass Msini = 1.8 Mjup, eccentricity e = 0.146
and a 1208 day period, corresponding to a semimajor axis of 2.7 AU. The planet
around HD167042 has a minimum mass Msini = 1.7 Mjup and a 412.6 day orbit,
corresponding to a semimajor axis of 1.3 AU. The eccentricity of HD167042b is
consistent with circular (e = 0.027+/-0.04), adding to the rare class of known
exoplanets in long-period, circular orbits similar to the Solar System gas
giants. Like all of the planets previously discovered around evolved A stars,
kappa CrBb and HD167042b orbit beyond 0.8 AU.


title:
The delta method for analytic functions of random operators with
  application to functional data

abstract:
  In this paper, the asymptotic distributions of estimators for the regularized
functional canonical correlation and variates of the population are derived.
The method is based on the possibility of expressing these regularized
quantities as the maximum eigenvalue and the corresponding eigenfunctions of an
associated pair of regularized operators, similar to the Euclidean case. The
known weak convergence of the sample covariance operator, coupled with a
delta-method for analytic functions of covariance operators, yields the weak
convergence of the pair of associated operators. From the latter weak
convergence, the limiting distributions of the canonical quantities of interest
can be derived with the help of some further perturbation theory.


title: SED modeling of Young Massive Stars

abstract:
  In this contribution, I review the applications and potential limitations of
the spectral energy distribution fitting tool that I have developed, with a
strong emphasis on the limits to which this tool can be used to improve our
understanding of massive star formation. I discuss why our current grid of
models cannot be used to distinguish between the several competing theories of
massive star formation. I also discuss stellar mass determinations, artificial
correlations between parameters in the grid of models, multiplicity, confusion,
dust assumptions, and unique fits. I briefly review the improvements we intend
to carry out for our next grid of models, which will eliminate many of these
limitations. Finally, I show examples of applications of this tool to massive
young stars.


title:
A hazard of open quantum dynamics: Markov approximations encounter map
  domains

abstract:
  A Markov approximation in open quantum dynamics can give unphysical results
when a map acts on a state that is not in its domain. This is examined here in
a simple example, an open quantum dynamics for one qubit in a system of two
interacting qubits, for which the map domains have been described quite
completely. A time interval is split into two parts and the map from the exact
dynamics for the entire interval is replaced by the conjunction of that same
map for both parts. If there is any correlation between the two qubits,
unphysical results can appear as soon as the map conjunction is used, even for
infinitesimal times. If the map is repeated an unlimited number of times, every
state is at risk of being taken outside the bounds of physical meaning.
Treatment by slippage of initial conditions is discussed.


title:
Anisotropic diffusion in continuum relaxation of stepped crystal
  surfaces

abstract:
  We study the continuum limit in 2+1 dimensions of nanoscale anisotropic
diffusion processes on crystal surfaces relaxing to become flat below
roughening. Our main result is a continuum law for the surface flux in terms of
a new continuum-scale tensor mobility. The starting point is the Burton,
Cabrera and Frank (BCF) theory, which offers a discrete scheme for atomic steps
whose motion drives surface evolution. Our derivation is based on the
separation of local space variables into fast and slow. The model includes: (i)
anisotropic diffusion of adsorbed atoms (adatoms) on terraces separating steps;
(ii) diffusion of atoms along step edges; and (iii) attachment-detachment of
atoms at step edges. We derive a parabolic fourth-order, fully nonlinear
partial differential equation (PDE) for the continuum surface height profile.
An ingredient of this PDE is the surface mobility for the adatom flux, which is
a nontrivial extension of the tensor mobility for isotropic terrace diffusion
derived previously by Margetis and Kohn. Approximate, separable solutions of
the PDE are discussed.


title: The elliptical galaxy NGC 5044: Stellar population and ionized gas

abstract:
  In this work we investigate the stellar population, metallicity distribution
and ionized gas in the elliptical galaxy NGC 5044, using long-slit spectroscopy
and a stellar population synthesis method. We found differences in the slope of
metal-line profiles along the galaxy which suggests an enhancement of alpha
elements, particularly towards the central region. The presence of a
non-thermal ionization source, such as a low-luminosity AGN and/or shock
ionization, is implied by the large values of the ratio (N II])Ha observed in
all sampled regions. However, the emission lines observed in the external
regions indicate the presence of an additional ionization source, probably hot,
post-AGB stars.


title:
Detecting the Rise and Fall of 21 cm Fluctuations with the Murchison
  Widefield Array

abstract:
  We forecast the sensitivity with which the Murchison Widefield Array (MWA)
can measure the 21 cm power spectrum of cosmic hydrogen, using radiative
transfer simulations to model reionization and the 21 cm signal. The MWA is
sensitive to roughly a decade in scale (wavenumbers of k ~ 0.1 - 1 h Mpc^{-1}),
with foreground contamination precluding measurements on larger scales, and
thermal detector noise limiting the small scale sensitivity. This amounts
primarily to constraints on two numbers: the amplitude and slope of the 21 cm
power spectrum on the scales probed. We find, however, that the redshift
evolution in these quantities can yield important information about
reionization. Although the power spectrum differs substantially across
plausible models, a generic prediction is that the amplitude of the 21 cm power
spectrum on MWA scales peaks near the epoch when the intergalactic medium (IGM)
is ~ 50% ionized. Moreover, the slope of the 21 cm power spectrum on MWA scales
flattens as the ionization fraction increases and the sizes of the HII regions
grow. Considering detection sensitivity, we show that the optimal MWA antenna
configuration for power spectrum measurements would pack all 500 antenna tiles
as close as possible in a compact core. The MWA is sensitive enough in its
optimal configuration to measure redshift evolution in the slope and amplitude
of the 21 cm power spectrum. Detecting the characteristic redshift evolution of
our models will confirm that observed 21 cm fluctuations originate from the
IGM, and not from foregrounds, and provide an indirect constraint on the
volume-filling factor of HII regions during reionization. After two years of
observations under favorable conditions, the MWA can constrain the filling
factor at an epoch when <x_i> ~ 0.5 to within roughly +/- 0.1 at 2-sigma.


title:
Upward shower rates at neutrino telescopes directly determine the
  neutrino flux

abstract:
  We show that the rate for upward showers from an isotropic cosmic neutrino
flux at neutrino telescopes like IceCube is independent of the neutrino-nucleon
cross section. For bins that span a relatively narrow range in energy, neither
scaling the cross section, nor changing its power-law energy behavior affects
the upward shower rate, which depends only on the flux. The neutrino flux can
be completely known since its spectral shape can be determined by comparing the
rates in neighboring bins. We also show that the downward shower rate varies
linearly with cross section with a proportionality constant determined by the
energy-dependence of the cross section, independent of the power-law behavior
of the flux. The normalization and energy dependence of the cross section can
be known by comparing the downward rates in neighboring bins.


title: Charm (and Beauty) Production at the Tevatron

abstract:
  We present recent results on heavy flavour production at Tevatron Run II for
typically ~1/fb of analysed proton-antiproton data at a c.m. energy of 1.96
TeV. This includes results on single and correlated open charm and bottom cross
sections, charm pair production kinematics, J/psi, psi(2S) and chi cross
sections and polarisation measurements in J/psi, psi(2S), Upsilon(1S), and
Upsilon(2S).


title: Independence-friendly cylindric set algebras

abstract:
  Independence-friendly logic is a conservative extension of first-order logic
that has the same expressive power as existential second-order logic. In her
Ph.D. thesis, Dechesne introduces a variant of independence-friendly logic
called IFG logic. We attempt to algebraize IFG logic in the same way that
Boolean algebra is the algebra of propositional logic and cylindric algebra is
the algebra of first-order logic.
  We define independence-friendly cylindric set algebras and prove two main
results. First, every independence-friendly cylindric set algebra over a
structure has an underlying Kleene algebra. Moreover, the class of such
underlying Kleene algebras generates the variety of all Kleene algebras. Hence
the equational theory of the class of Kleene algebras that underly an
independence-friendly cylindric set algebra is finitely axiomatizable. Second,
every one-dimensional independence-friendly cylindric set algebra over a
structure has an underlying monadic Kleene algebra. However, the class of such
underlying monadic Kleene algebras does not generate the variety of all monadic
Kleene algebras. Finally, we offer a conjecture about which subvariety of
monadic Kleene algebras the class of such monadic Kleene algebras does
generate.


title:
Level-dynamic approach to the excited spectra of the Jahn-Teller model -
  kink-train lattice and 'glassy' quantum phase

abstract:
  The dynamics of excited phonon spectra of the Exe Jahn-Teller (hereafter, JT)
model mapped onto the generalized Calogero-Moser (gCM) gas of pseudoparticles
implies a complex interplay between nonlinearity and fluctuations of
quasiparticle trajectories. A broad crossover appears in a pseudotime
(interaction strength) between the initial oscillator region and the nonlinear
region of the kink-train lattice as a superlattice of the kink-antikink gCM
trajectories. The local nonlinear fluctuations, nuclei (droplets) of the
growing kink phase arise at the crossover, forming a new intermediate droplet
"glassy" phase as a precursor of the kink phase. The "glassy" phase is related
to a broad maximum in the entropy of the probability distributions of
pseudoparticle accelerations, or level curvatures. The kink-train lattice phase
with multiple kink-antikink collisions is stabilised by long-range correlations
when approaching a semiclassical limit. A series of bifurcations of
nearest-level spacings were recognised as signatures of pre-chaotic behaviour
at the quantum level in the kink phase. Statistical characteristics can be seen
to confirm the coexistence within all of the spectra of both regularity and
chaoticity to a varying extent (nonuniversality). Regions are observed within
which one of the phases is dominant.


title: Worldwide R&D of Virtual Observatory

abstract:
  Virtual Observatory (VO) is a data intensive online astronomical research and
education environment, taking advantages of advanced information technologies
to achieve seamless and uniform access to astronomical information. The concept
of VO was introduced in late of 1990s to meet challenges brought up with data
avalanche in astronomy. This paper reviews current status of International
Virtual Observatory Alliance, technical highlights from world wide VO projects,
and a brief introduction of Chinese Virtual Observatory.


abstract:
  The aim of this paper is to construct the Poincare isomorphism in K-theory on
manifolds with edges. We show that the Poincare isomorphism can naturally be
constructed in the framework of noncommutative geometry. More precisely, to a
manifold with edges we assign a noncommutative algebra and construct an
isomorphism between the K-group of this algebra and the K-homology group of the
manifold with edges viewed as a compact topological space.


title: Randomness and metastability in CDMA paradigms

abstract:
  Code Division Multiple Access (CDMA) in which the signature code assignment
to users contains a random element has recently become a cornerstone of CDMA
research. The random element in the construction is particularly attractive in
that it provides robustness and flexibility in application, whilst not making
significant sacrifices in terms of multiuser efficiency. We present results for
sparse random codes of two types, with and without modulation. Simple
microscopic consideration on system samples would suggest differences in the
phase space of the two models, but we demonstrate that the thermodynamic
results and metastable states are equivalent in the minimum bit error rate
detector. We analyse marginal properties of interactions and also make
analogies to constraint satisfiability problems in order to understand
qualitative features of detection and metastable states. This may have
consequences for developing algorithmic methods to escape metastable states,
thus improving decoding performance.


title:
Geometric Frustration and Interparticle Gap Size Distributions in
  Ordered Hexagonal Polydisperse Disk Packs

abstract:
  This work analyzes the distribution and size of interparticle gaps arising in
an ensemble of hexagonal unit structures in the xy plane when packing disks
with a Gaussian distribution of radii with mean (r) and standard deviation
$\Delta r$. During the course of this investigation an equivalency is
established between gaps arising in hexagonal unit structure packs and
nine-ball billiard rack patterns. An analytic expression is derived for the
probability distribution and location of interparticle gaps of magnitude
$\Gamma$. Due to the number of variables and large number of possible
arrangements, a Monte Carlo simulation has been conducted to complement and
probe the analytic form for three very different systems: i) billiard balls
with Billiard Congress of America (BCA) specifications, ii) US pennies with
specifications of the US Mint, and iii) a hypothetical system with $r = 1.0 m$
and $\Delta r = 1x10^{-10}$ m corresponding to the scale of one atomic radius.
In each case, probability density distributions of gap sizes have been
calculated for those $\Delta r$ above, and also for 2$\Delta r$ and 0.5$\Delta
r$, respectively. A general result is presented for the probability of a
nonzero normalized ($\frac{\Gamma}{\Delta r}$) gap size arising, $P(\Gamma \geq
\alpha \Delta r)= 1-0.124\alpha$, where $\alpha$ is a constant $\leq 5.0$. This
curious result reflects the phenomenon of geometric frustration; the inability
of the system to simultaneously satisfy all geometric constraints required by a
perfect-rack sans interparticle gaps.


title: Weighted Ehrhart Theory and Orbifold Cohomology

abstract:
  We introduce the notion of a weighted $\delta$-vector of a lattice polytope.
Although the definition is motivated by motivic integration, we study weighted
$\delta$-vectors from a combinatorial perspective. We present a version of
Ehrhart Reciprocity and prove a change of variables formula. We deduce a new
geometric interpretation of the coefficients of the Ehrhart $\delta$-vector.
More specifically, they are sums of dimensions of orbifold cohomology groups of
a toric stack.


title:
Elastic constants and volume changes associated with two high-pressure
  rhombohedral phase transformations in vanadium

abstract:
  We present results from ab initio calculations of the mechanical properties
of the rhombohedral phase (beta) of vanadium metal reported in recent
experiments, and other predicted high-pressure phases (gamma and bcc), focusing
on properties relevant to dynamic experiments. We find that the volume change
associated with these transitions is small: no more than 0.15% (for beta -
gamma). Calculations of the single crystal and polycrystal elastic moduli
(stress-strain coefficients) reveal a remarkably small discontinuity in the
shear modulus and other elastic properties across the phase transitions even at
zero temperature where the transitions are first order.


title:
Creation of the X-ray Cavity Jet and its Radio Lobe in M87/Virgo with
  Cosmic Rays; Relevance to Relic Radio Sources

abstract:
  Young cavities in the X-ray emitting hot gas in galaxy clusters are often
filled with radio synchrotron emission and it is widely thought that the
cavities are inflated by these cosmic rays. At a later stage of its evolution,
when the cavity becomes buoyant, the converging flow of gas beneath the cavity
results in a filament of thermal gas, a cavity jet, that moves radially outward
at large subsonic velocities. As the cavity jet forms, the cosmic ray electrons
may diffuse through the cavity walls, filling a large volume surrounding the
cavity jet, as observed in M87/Virgo and elsewhere, sometimes referred to as
relic radio sources. We compute the combined evolution of cosmic rays, cavities
and cavity jets. The observed pattern in M87/Virgo can be reached in 100 Myrs,
matching the synchrotron age of the extended radio source. A 20-30 kpc long
cavity jet is surrounded by a quasi-spherical radio lobe 40 kpc in diameter,
but the initial cavity has disappeared. At later times the cavity jet will fall
back to the origin, leaving only the extended radio source. The combined
jet-lobe evolution in M87/Virgo requires a total cosmic ray energy that is more
than 10 times larger than that usually assumed, 4PV.


abstract:
  We define Atiyah-Bott index on stratified manifolds and express it in
topological terms. By way of example, we compute this index for geometric
operators on manifolds with edges.


title: Non-empirical pairing functional

abstract:
  The present contribution reports the first systematic finite-nucleus
calculations performed using the Energy Density Functional method and a
non-empirical pairing functional derived from low-momentum interactions. As a
first step, the effects of Coulomb and the three-body force are omitted while
only the bare two-nucleon interaction at lowest order is considered. To cope
with the finite-range and non-locality of the bare nuclear interaction, the 1S0
channel of Vlowk is mapped onto a convenient operator form. For the first time,
neutron-neutron and proton-proton pairing correlations generated in finite
nuclei by the direct term of the two-nucleon interaction are characterized in a
systematic manner. Eventually, such predictions are compared to those obtained
from empirical local functionals derived from density-dependent zero range
interactions. The characteristics of the latter are analyzed in view of that
comparison and a specific modification of their isovector density dependence is
suggested to accommodate Coulomb effects and the isovector trend of neutron
gaps at the same time.


title:
SkyMouse: A smart interface for astronomical on-line resources and
  services

abstract:
  With the development of network and the World Wide Web (WWW), the Internet
has been growing and changing dramatically. More and more on-line database
systems and different kinds of services are available for astronomy research.
How to help users find their way through the jungle of information services
becomes an important challenge. Although astronomers have been aware of the
importance of interoperability and introduced the concept of Virtual
Observatory as a uniform environment for future astronomical on-line resources
and services, transparent access to heterogeneous on-line information is still
difficult.
  SkyMouse is a lightweight interface for distributed astronomical on-line
resources and services, which is designed and developed by us, i.e., Chinese
Virtual Observatory Project. Taking advantage of screen word-capturing
technology, different kinds of information systems can be queried through
simple mouse actions, and results are returned in a uniform web page. SkyMouse
is an easy to use application, aiming to show basic information or to create a
comprehensive overview of a specific astronomical object.
  In this paper current status of on-line resources and services access is
reviewed; system architecture, features and functions of SkyMouse are
described; challenges for intelligent interface for on-line astronomical
resources and services are discussed.


title:
Contextual Information Retrieval based on Algorithmic Information Theory
  and Statistical Outlier Detection

abstract:
  The main contribution of this paper is to design an Information Retrieval
(IR) technique based on Algorithmic Information Theory (using the Normalized
Compression Distance- NCD), statistical techniques (outliers), and novel
organization of data base structure. The paper shows how they can be integrated
to retrieve information from generic databases using long (text-based) queries.
Two important problems are analyzed in the paper. On the one hand, how to
detect "false positives" when the distance among the documents is very low and
there is actual similarity. On the other hand, we propose a way to structure a
document database which similarities distance estimation depends on the length
of the selected text. Finally, the experimental evaluations that have been
carried out to study previous problems are shown.


title:
Magnetic Field Amplification and Rapid Time Variations in SNR RX
  J1713.7-3946

abstract:
  Evidence is accumulating suggesting that collisionless shocks in supernova
remnants (SNRs) can amplify the interstellar magnetic field to hundreds of
microgauss or even milli-gauss levels, as recently claimed for SNR RX
J1713.7-3946. If these fields exist, they are almost certainly created by
magnetic field amplification (MFA) associated with the efficient production of
cosmic rays by diffusive shock acceleration (DSA) and their existence
strengthens the case for SNRs being the primary source of galactic cosmic ray
ions to the `knee' and beyond. However, the high magnetic field values in SNRs
are obtained exclusively from the interpretation of observations of radiation
from relativistic electrons and if MFA via nonlinear DSA produces these fields
the magnetic field that determines the maximum ion energy will be substantially
less than the field that determines the maximum electron energy. We use results
of a steady-state Monte Carlo simulation to show how nonlinear effects from
efficient cosmic ray production and MFA reduce the maximum energy of protons
relative to what would be expected from test-particle acceleration.


title:
Finite temperature phase diagram of a spin-polarized ultracold Fermi gas
  in a highly elongated harmonic trap

abstract:
  We investigate the finite temperature properties of an ultracold atomic Fermi
gas with spin population imbalance in a highly elongated harmonic trap.
Previous studies at zero temperature showed that the gas stays in an exotic
spatially inhomogeneous Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) superfluid
state at the trap center; while moving to the edge, the system changes into
either a non-polarized Bardeen-Cooper-Schriffer superfluid ($P<P_c$) or a fully
polarized normal gas ($P>P_c$), depending on the smallness of the spin
polarization $P$, relative to a critical value $P_c$. In this work, we show how
these two phase-separation phases evolve with increasing temperature, and
thereby construct a finite temperature phase diagram. For typical interactions,
we find that the exotic FFLO phase survives below one-tenth of Fermi degeneracy
temperature, which seems to be accessible in the current experiment. The
density profile, equation of state, and specific heat of the polarized system
have been calculated and discussed in detail. Our results are useful for the
on-going experiment at Rice University on the search for FFLO states in
quasi-one-dimensional polarized Fermi gases.


title: Magnetically Arrested Disks and Origin of Poynting Jets: Numerical Study

abstract:
  The dynamics and structure of accretion disks, which accumulate the vertical
magnetic field in the centers, are investigated using two- and
three-dimensional MHD simulations. The central field can be built up to the
equipartition level and disrupts a nearly axisymmetric outer accretion disk
inside a magnetospheric radius, forming a magnetically arrested disk (MAD). In
the MAD, the mass accretes in a form of irregular dense spiral streams and the
vertical field, split into separate bundles, penetrates through the disk plane
in low-density magnetic islands. The accreting mass, when spiraling inward,
drags the field and twists it around the axis of rotation, resulting in
collimated Poynting jets in the polar directions. These jets are powered by the
accretion flow with the efficiency up to ~1.5% (in units \dot{M}c^2). The
spiral flow pattern in the MAD is dominated by modes with low azimuthal
wavenumbers m~1-5 and can be a source of quasi-periodic oscillations in the
outgoing radiation. The formation of MAD and Poynting jets can naturally
explain the observed changes of spectral states in Galactic black hole
binaries. Our study is focused on black hole accretion flows; however, the
results can also be applicable to accretion disks around nonrelativistic
objects, such as young stellar objects and stars in binary systems.


title: Integrated Harnack inequalities on Lie groups

abstract:
  We show that the logarithmic derivatives of the convolution heat kernels on a
uni-modular Lie group are exponentially integrable. This result is then used to
prove an "integrated" Harnack inequality for these heat kernels. It is shown
that this integrated Harnack inequality is equivalent to a version of Wang's
Harnack inequality. (A key feature of all of these inequalities is that they
are dimension independent.) Finally, we show these inequalities imply
quasi-invariance properties of heat kernel measures for two classes of infinite
dimensional "Lie" groups.


title: Lattice points in Minkowski sums

abstract:
  Fakhruddin has proved that for two lattice polygons P and Q any lattice point
in their Minkowski sum can be written as a sum of a lattice point in P and one
in Q, provided P is smooth and the normal fan of P is a subdivision of the
normal fan of Q. We give a shorter combinatorial proof of this fact that does
not need the smoothness assumption on P.


title: A note on a degree sum condition for long cycles in graphs

abstract:
  We conjecture that a 2-connected graph $G$ of order $n$, in which
$d(x)+d(y)\geq n-k$ for every pair of non-adjacent vertices $x$ and $y$,
contains a cycle of length $n-k$ ($k<n/2$), unless $G$ is bipartite and $n-k$
is odd. This generalizes to long cycles a well-known degree sum condition for
hamiltonicity of Ore. The conjecture is shown to hold for $k=1$.


title: Quantum transport and spin dynamics on shearless tori

abstract:
  We investigate for quantum dynamics in phase-space regions containing
``shearless tori''. We show that the properties of these peculiar classical
phase-space structures -- important to the dynamics of tokamaks -- may be
exploited for quantum information applications. In particular we show that
shearless tori permit the non-dispersive transmission of localized wavepackets.
The quantum many-body Hamiltonian of a Heisenberg ferromagnetic spin chain,
subjected to an oscillating magnetic field, can be reduced to a classical
one-body ``image'' dynamical system which is the well-studied Harper map. The
Harper map belongs to a class of Hamiltonian systems (non-twist maps) which
contain shearless tori. We show that a variant with sinusoidal time driving
``driven Harper model'' produces shearless tori which are especially suitable
for quantum state transfer. The behavior of the concurrence is investigated as
an example.


title: The Cuntz semigroup of some spaces of dimension at most two

abstract:
  It is shown that the Cuntz semigroup of a space with dimension at most two,
and with second cohomology of its compact subsets equal to zero, is isomorphic
to the ordered semigroup of lower semicontinuous functions on the space with
values in the natural numbers with the infinity adjoined. This computation is
then used to obtain the Cuntz semigroup of all compact surfaces. A converse to
the first computation is also proven: if the Cuntz semigroup of a separable
C*-algebra is isomorphic to the lower semicontinuous functions on a topological
space with values in the extended natural numbers, then the C*-algebra is
commutative up to stability, and its spectrum satisfies the dimensional and
cohomological conditions mentioned above.


title:
Critical Exponents and Particle Multiplicity Distributions in High
  Energy Collisions

abstract:
  Data from the L3, Tasso, Opal and Delphi collaborations are analyzed in terms
of a statistical model of high energy collisions. The model contains a power
law critical exponent tau and Levy index alpha. These data are used to study
values of tau and alpha. The very high multiplicity events in L3, Opal and
Delphi are consistent with a model based on a Feynman-Wilson gas which has a
tail exponent tau=3/2 and alpha=1/2.


title:
The forcing partial order on a family of braids forced by pseudo-Anosov
  3-braids

abstract:
  Li-York theorem tells us that a period 3 orbit for a continuous map of the
interval into itself implies the existence of a periodic orbit of every period.
This paper concerns an analogue of the theorem for homeomorphisms of the
2-dimensional disk. In this case a periodic orbit is specified by a braid type
and on the set of all braid types Boyland's dynamical partial order can be
defined. We describe the partial order on a family of braids and show that a
period 3 orbit of pseudo-Anosov braid type implies the Smale-horseshoe map
which is a factor possessing complicated chaotic dynamics.


title:
Determining the relative evolutionary stages of very young massive star
  formation regions

abstract:
  We have recently completed an observing program with the Australia Telescope
Compact Array towards massive star formation regions traced by 6.7 GHz methanol
maser emission. We found the molecular cores could be separated into groups
based on their association with/without methanol maser and 24 GHz continuum
emission. Analysis of the molecular and ionised gas properties suggested the
cores within the groups may be at different evolutionary stages. In this
contribution we derive the column densities and temperatures of the cores from
the NH3 emission and investigate if this can be used as an indicator of the
relative evolutionary stages of cores in the sample.
  The majority of cores are well fit using single-temperature large velocity
gradient models, and exhibit a range of temperatures from ~10 K to >200 K.
Under the simple but reasonable assumption that molecular gas in the cores will
heat up and become less quiescent with age due to feedback from the powering
source(s), the molecular gas kinetic temperature combined with information of
the core kinematics seems a promising probe of relative core age in the
earliest evolutionary stages of massive star formation.


title: There is a Van Douwen MAD family

abstract:
  We prove in ZFC that there is a MAD family of functions in omega^omega which
is also maximal with respect to infinite partial functions. This solves a 20
year old question of Van Douwen. We also strengthen a result of J. Steprans
stating that strongly MAD families of functions cannot be analytic. We show
that analytic MAD families of functions, if they exist, must satisfy some
strong constraints.


title: Sheaves as modules

abstract:
  We revisit sheaves on locales by placing them in the context of the theory of
quantale modules. The local homeomorphisms $p:X\to B$ are identified with the
Hilbert $B$-modules that are equipped with a natural notion of basis. The
homomorphisms of these modules are necessarily adjointable, and the resulting
self-dual category yields a description of the equivalence between local
homeomorphisms and sheaves whereby morphisms of sheaves arise as the ``operator
adjoints'' of the maps of local homeomorphisms.


title:
Viscoelasticity and primitive path analysis of entangled polymer
  liquids: From f-actin to polyethylene

abstract:
  We combine computer simulations and scaling arguments to develop a unified
view of polymer entanglement based on the primitive path analysis (PPA) of the
microscopic topological state. Our results agree with experimentally measured
plateau moduli for three different polymer classes over a wide rangeof reduced
polymer densities: (i) semi-dilute theta solutions of synthetic polymers, (ii)
the corresponding dense melts above the glass transition or crystallization
temperature, and (iii) solutions of semi-flexible (bio)polymers such as f-actin
or suspensions of rodlike viruses. Together these systems cover the entire
range from loosely to tightly entangled polymers. In particular, we argue that
the primitive path analysis renormalizes a loosely to a tightly entangled
system and provide a new explanation of the successful Lin-Noolandi packing
conjecture for polymer melts.


title: On stable numerical differentiation

abstract:
  Based on a regularized Volterra equation, two different approaches for
numerical differentiation are considered. The first approach consists of
solving a regularized Volterra equation while the second approach is based on
solving a disretized version of the regularized Volterra equation. Numerical
experiments show that these methods are efficient and compete favorably with
the variational regularization method for stable calculating the derivatives of
noisy functions.


title:
Absolutely Continuous Spectrum of a Polyharmonic Operator with a Limit
  Periodic Potential in Dimension Two

abstract:
  We consider a polyharmonic operator $H=(-\Delta)^l+V(x)$ in dimension two
with $l\geq 6$, $l$ being an integer, and a limit-periodic potential $V(x)$. We
prove that the spectrum contains a semiaxis of absolutely continuous spectrum.


title:
A Modification of the Sarkar-Wang Algorithm and an Analysis of its
  Computational Complexity

abstract:
  The Sarkar-Wang algorithm computes the hat version of the Heegaard Floer
homology of a closed oriented three manifold. This paper analyzes the
computational complexity of the Sarkar-Wang algorithm; then the algorithm is
modified to obtain a better bound. Then the computational complexity of
calculating HFK hat from a Heegaard diagram by means of the modified
Sarkar-Wang algorithm is also analyzed. Under certain assumptions it is shown
that the modified Sarkar-Wang algorithm is faster than the
Manolescu-Ozsvath-Sarkar algorithm.


title:
Optimization of Information Rate Upper and Lower Bounds for Channels
  with Memory

abstract:
  We consider the problem of minimizing upper bounds and maximizing lower
bounds on information rates of stationary and ergodic discrete-time channels
with memory. The channels we consider can have a finite number of states, such
as partial response channels, or they can have an infinite state-space, such as
time-varying fading channels. We optimize recently-proposed information rate
bounds for such channels, which make use of auxiliary finite-state machine
channels (FSMCs). Our main contribution in this paper is to provide iterative
expectation-maximization (EM) type algorithms to optimize the parameters of the
auxiliary FSMC to tighten these bounds. We provide an explicit, iterative
algorithm that improves the upper bound at each iteration. We also provide an
effective method for iteratively optimizing the lower bound. To demonstrate the
effectiveness of our algorithms, we provide several examples of partial
response and fading channels, where the proposed optimization techniques
significantly tighten the initial upper and lower bounds. Finally, we compare
our results with an improved variation of the \emph{simplex} local optimization
algorithm, called \emph{Soblex}. This comparison shows that our proposed
algorithms are superior to the Soblex method, both in terms of robustness in
finding the tightest bounds and in computational efficiency. Interestingly,
from a channel coding/decoding perspective, optimizing the lower bound is
related to increasing the achievable mismatched information rate, i.e., the
information rate of a communication system where the decoder at the receiver is
matched to the auxiliary channel, and not to the original channel.


title: Mapping Incidences

abstract:
  We show that any finite set S in a characteristic zero integral domain can be
mapped to the finite field of order p, for infinitely many primes p, preserving
all algebraic incidences in S. This can be seen as a generalization of the
well-known Freiman isomorphism lemma, and we give several combinatorial
applications (such as sum-product estimates).


title: BZ-MC-BP Model for Jet Production from Black Hole Accretion Disc

abstract:
  Three energy mechanisms invoking large-scale magnetic fields are incorporated
in a model to interpret jet production in black hole (BH) systems, i.e., the
Blandford-Znajek (BZ), the magnetic coupling (MC) and Blandford-Payne (BP)
processes. These energy mechanisms can coexist in BH accretion disc based on
the magnetic field configurations constrained by the screw instability,
provided that the BH spin and the power-law index indicating the variation of
the magnetic field at an accretion disc are greater than some critical values.
In this model the jets are driven by the BZ process in the Poynting flux regime
and by the BP process in the hydromagnetic regime, being consistent with the
spine/sheath jet structure observed in BH sources of stellar and supermassive
size.


title: Spherical functors

abstract:
  This paper has been withdrawn and replaced by arXiv:1309.5035. In this paper
we describe some examples of so called spherical functors between triangulated
categories, which generalize the notion of a spherical object. We also give
sufficient conditions for a collection of spherical functors to yield a weak
representation of the category of tangles, and prove a structure theorem for
such representations under certain restrictions.


title:
Three-Dimensional Simulations of Kelvin-Helmholtz Instability in Settled
  Dust Layers in Protoplanetary Disks

abstract:
  As dust settles in a protoplanetary disk, a vertical shear develops because
the dust-rich gas in the midplane orbits at a rate closer to true Keplerian
than the slower-moving dust-depleted gas above and below. A classical analysis
(neglecting the Coriolis force and differential rotation) predicts that
Kelvin-Helmholtz instability occurs when the Richardson number of the
stratified shear flow is below roughly one-quarter. However, earlier numerical
studies showed that the Coriolis force makes layers more unstable, whereas
horizontal shear may stabilize the layers. Simulations with a 3D spectral code
were used to investigate these opposing influences on the instability in order
to resolve whether such layers can ever reach the dense enough conditions for
the onset of gravitational instability. I confirm that the Coriolis force, in
the absence of radial shear, does indeed make dust layers more unstable,
however the instability sets in at high spatial wavenumber for thicker layers.
When radial shear is introduced, the onset of instability depends on the
amplitude of perturbations: small amplitude perturbations are sheared to high
wavenumber where further growth is damped; whereas larger amplitude
perturbations grow to magnitudes that disrupt the dust layer. However, this
critical amplitude decreases sharply for thinner, more unstable layers. In 3D
simulations of unstable layers, turbulence mixes the dust and gas, creating
thicker, more stable layers. I find that layers with minimum Richardson numbers
in the approximate range 0.2 -- 0.4 are stable in simulations with horizontal
shear.


title: Recent Results from the JLab Spin Physics Program

abstract:
  Select recent results from the Thomas Jefferson National Laboratory Spin
Physics program, along with the perspective on some upcoming experiments.


title: Stirling's formula derived simply

abstract:
  Stirling's formula, the asymptotic expansion of $n!$ for $n$ large, or of
$\Gamma(z)$ for $z\to \infty$, is derived directly from the recursion equation
$\Gamma(z+1) =z \Gamma(s)$ and the normalization condition $\Gamma ({1/2})
=\sqrt{\pi}$.


title: Radiation Damage in Polarized Ammonia Solids

abstract:
  Solid NH3 and ND3 provide a highly polarizable, radiation resistant source of
polarized protons and deuterons and have been used extensively in high
luminosity experiments investigating the spin structure of the nucleon. Over
the past twenty years, the UVA polarized target group has been instrumental in
producing and polarizing much of the material used in these studies, and many
practical considerations have been learned in this time. In this discussion, we
analyze the polarization performance of the solid ammonia targets used during
the recent JLab Eg4 run. Topics include the rate of polarization decay with
accumulated charge, the annealing procedure for radiation damaged targets to
recover polarization, and the radiation induced change in optimum microwave
frequency used to polarize the sample. We also discuss the success we have had
in implementing frequency modulation of the polarizing microwave frequency.


title:
Exploiting Multi-Antennas for Opportunistic Spectrum Sharing in
  Cognitive Radio Networks

abstract:
  In cognitive radio (CR) networks, there are scenarios where the secondary
(lower priority) users intend to communicate with each other by
opportunistically utilizing the transmit spectrum originally allocated to the
existing primary (higher priority) users. For such a scenario, a secondary user
usually has to trade off between two conflicting goals at the same time: one is
to maximize its own transmit throughput; and the other is to minimize the
amount of interference it produces at each primary receiver. In this paper, we
study this fundamental tradeoff from an information-theoretic perspective by
characterizing the secondary user's channel capacity under both its own
transmit-power constraint as well as a set of interference-power constraints
each imposed at one of the primary receivers. In particular, this paper
exploits multi-antennas at the secondary transmitter to effectively balance
between spatial multiplexing for the secondary transmission and interference
avoidance at the primary receivers. Convex optimization techniques are used to
design algorithms for the optimal secondary transmit spatial spectrum that
achieves the capacity of the secondary transmission. Suboptimal solutions for
ease of implementation are also presented and their performances are compared
with the optimal solution. Furthermore, algorithms developed for the
single-channel transmission are also extended to the case of multi-channel
transmission whereby the secondary user is able to achieve opportunistic
spectrum sharing via transmit adaptations not only in space, but in time and
frequency domains as well.


title: Static exteriors for nonstatic braneworld stars

abstract:
  We study possible static non-Schwarzschild exteriors for nonstatic
spherically symmetric stars in a Randall $&$ Sundrum type II braneworld
scenario. Thus, the vacuum region outside the surface of a star is assumed to
be a static solution to the equation $^{(4)}R = 0$, where $^{(4)}R $ is the
scalar curvature of the 4-dimensional Ricci tensor with spherical symmetry.
Firstly, we show that for nonstatic spheres the standard matching conditions
are much more restrictive than for static ones; they lead to a specific
requirement on the vacuum region outside of a nonstatic star, that is absent in
the case of static stars. Secondly, without making any assumption about the
bulk, or the material medium inside the star, we prove the following theorem on
the brane: for {\it any} nonstatic spherical star, without rotation, there are
only two possible static exteriors; these are the Schwarzschild and the
"Reissner-Nordstr{\"o}m-like" exteriors. This is quite distinct from the case
of stars in hydrostatic equilibrium which admit a much larger family of
non-Schwarzschild static exteriors.


title: Emergent spacetimes

abstract:
  We discuss the possibility that spacetime geometry may be an emergent
phenomenon. This idea has been motivated by the Analogue Gravity programme.
These are systems where the kinematics of small perturbations are dominated by
an effective gravitational field. In these models there is no obvious
connection between the "gravitational" field tensor and the Einstein equations,
as the emergent spacetime geometry arises as a consequence of linearising
around some classical field. After a brief introduction on this topic, we
present our recent contributions to the field.


title: Dalitz Plot Analysis of the Decay B0(B0bar) --> K+/- pi-/+ pi0

abstract:
  We report a Dalitz-plot analysis of the charmless hadronic decays of neutral
B mesons to K^+/- pi^-/+ pi^0. With a sample of (231.8+/-2.6) 10^6 Upsilon(4S)
to B Bbar decays collected by the BABAR detector at the PEP-II
asymmetric-energy B Factory at SLAC, we measure the magnitudes and phases of
the intermediate resonant and nonresonant amplitudes for B0 and B0bar decays
and determine the corresponding CP-averaged branching fractions and charge
asymmetries. The inclusive branching fraction and CP-violating charge asymmetry
are measured to be BF(B0 --> K+ pi^- pi0)=(35.7-1.5+2.6 +/-2.2)10^(-6), and
A_CP=-0.030+0.045-0.051 +/-0.055 where the first errors are statistical and the
second systematic. We observe the decay B0 --> K^{*0}(892) pi^0 with the
branching fraction BF(B0 --> K^{*0}(892) pi^0)=(3.6_{-0.8}^{+0.7} +/-0.4)
10^{-6}. This measurement differs from zero by 5.6 standard deviations
(including the systematic uncertainties). The selected sample also contains B0
--> D^0bar pi^0 decays where D^0bar --> K+ pi-, and we measure BF(B0 --> D0bar
pi^0)=(2.93 +/- 0.17 +/-0.18) 10^{-4}.


title: A pumped atom laser

abstract:
  We present the experimental realization of a pumped atom laser. We
demonstrate the pumping through measurements of the source and laser-mode atom
numbers, making a rate equation study of the pumping process.


title: Non-trivalent graph cocycle and cohomology of the long knot space

abstract:
  In this paper we show that via the configuration space integral construction
a non-trivalent graph cocycle can also yield a non-zero cohomology class of the
space of higher (and even) codimensional long knots. This simultaneously proves
that the Browder operation induced by the operad action defined by R. Budney is
not trivial.


title: Accreting neutron star spins and the equation of state

abstract:
  X-ray timing of neutron stars in low-mass X-ray binaries (LMXBs) with RXTE
has since 1996 revealed several distinct high-frequency phenomena. Among these
are oscillations during thermonuclear (type-I) bursts, which (in addition to
persistent X-ray pulsations) are thought to trace the neutron star spin. Recent
discoveries bring the total number of measured LMXB spin rates to 22. An open
question is why the majority of the ~100 known neutron stars in LMXBs show
neither pulsations nor burst oscillations.
  Recent observations suggest that persistent pulsations may be more common
than previously thought, although detectable intermittently, and in some cases
at very low duty cycles. For example, the 377.3 Hz pulsations in HETE
J1900.1-2455 were only present in the first few months of it's outburst, and
have been absent since (although X-ray activity continues). Intermittent
(persistent) pulsations have since been detected in a further two sources. In
two of these three systems the pulsations appear to be related to the
thermonuclear burst activity, but in the third (Aql X-1) they are not. This
phenomenon offers new opportunities for spin measurements in known systems.
  Such measurements can constrain the poorly-known neutron star equation of
state, and neutron stars in LMXBs offer observational advantages over
rotation-powered pulsars which make the detection of more rapidly-spinning
examples more likely. Even so, spin rates of at least 50% faster than the
present maximum appear necessary to give constraints stringent enough to
discriminate between the various models. Although the future prospects for such
rapidly-spinning objects do not appear optimistic, several additional
observational approaches are possible for LMXBs.


title: Sequestering CP Violation and GIM-Violation with Warped Extra Dimensions

abstract:
  We propose a model of spontaneous CP violation to address the strong CP
problem in warped extra dimensions that relies on sequestering flavor and CP
violation. We assume that brane-localized Higgs Yukawa interactions respect a
U(3) flavor symmetry that is broken only by bulk fermion mass and Yukawa terms.
All CP violation arises from the vev of a CP-odd scalar field localized in the
bulk. To suppress radiative corrections to theta-bar, the doublet quarks in
this model are localized on the IR brane. We calculate constraints from
flavor-changing neutral currents (FCNCs), precision electroweak measurements,
CKM unitarity, and the electric dipole moments in this model and predict
theta-bar to be at least about 10^-12.


title: Rotating Black Holes in Einstein-Maxwell-Dilaton Gravity

abstract:
  We present a new class of slowly rotating black hole solutions in
$(n+1)$-dimensional $(n\geq3)$ Einstein-Maxwell-dilaton gravity in the presence
of Liouville-type potential for the dilaton field and an arbitrary value of the
dilaton coupling constant. Because of the presence of the dilaton field, the
asymptotic behaviour of these solutions are neither flat nor (A)dS. In the
absence of a dilaton field, our solution reduces to the $(n+1)$-dimensional
Kerr-Newman modification thereof for small rotation parameter \cite{Aliev2}. We
also compute the angular momentum and the gyromagnetic ratio of these rotating
dilaton black holes.


title: Hawking-Moss Tunneling in Noncommutative Eternal Inflation

abstract:
  The quantum behavior of noncommutative eternal inflation is quite different
from the usual knowledge. Unlike the usual eternal inflation, the quantum
fluctuation of noncommutative eternal inflation is suppressed by the Hubble
parameter. Due to this, we need to reconsider many conceptions of eternal
inflation. In this paper we study the Hawking-Moss tunneling in noncommutative
eternal inflation using the stochastic approach. We obtain a brand-new form of
the tunneling probability for this process and find that the Hawking-Moss
tunneling is more unlikely to take place in the noncommutative case than in the
usual one. We also conclude that the lifetime of a metastable de-Sitter (dS)
vacuum in the noncommutative spacetime is longer than that in the commutative
case.


title:
Bright-dark solitons and their collisions in mixed N-coupled nonlinear
  Schr\"odinger equations

abstract:
  Mixed type (bright-dark) soliton solutions of the integrable N-coupled
nonlinear Schr{\"o}dinger (CNLS) equations with mixed signs of focusing and
defocusing type nonlinearity coefficients are obtained by using Hirota's
bilinearization method. Generally, for the mixed N-CNLS equations the bright
and dark solitons can be split up in $(N-1)$ ways. By analysing the collision
dynamics of these coupled bright and dark solitons systematically we point out
that for $N>2$, if the bright solitons appear in at least two components,
non-trivial effects like onset of intensity redistribution, amplitude dependent
phase-shift and change in relative separation distance take place in the bright
solitons during collision. However their counterparts, the dark solitons,
undergo elastic collision but experience the same amplitude dependent
phase-shift as that of bright solitons. Thus in the mixed CNLS system there
co-exist shape changing collision of bright solitons and elastic collision of
dark solitons with amplitude dependent phase-shift, thereby influencing each
other mutually in an intricate way.


title:
Positive and negative effective mass of classical particles in
  oscillatory and static fields

abstract:
  A classical particle oscillating in an arbitrary high-frequency or static
field effectively exhibits a modified rest mass m_eff derived from the particle
averaged Lagrangian. Relativistic ponderomotive and diamagnetic forces, as well
as magnetic drifts, are obtained from the m_eff dependence on the guiding
center location and velocity. The effective mass is not necessarily positive
and can result in backward acceleration when an additional perturbation force
is applied. As an example, adiabatic dynamics with m_|| > 0 and m_|| < 0 is
demonstrated for a wave-driven particle along a dc magnetic field, m_|| being
the effective longitudinal mass derived from m_eff. Multiple energy states are
realized in this case, yielding up to three branches of m_|| for a given
magnetic moment and parallel velocity.


title:
On the cycle structure of hamiltonian k-regular bipartite graphs of
  order 4k

abstract:
  It is shown that a hamiltonian $n/2$-regular bipartite graph $G$ of order
$2n>8$ contains a cycle of length $2n-2$. Moreover, if such a cycle can be
chosen to omit a pair of adjacent vertices, then $G$ is bipancyclic.


title: Szemeredi-Trotter type theorem and sum-product estimate in finite fields

abstract:
  We study a Szemer\'edi-Trotter type theorem in finite fields. We then use
this theorem to obtain an improved sum-product estimate in finite fields.


title:
Relativistic corrections to transition frequencies of Fe I and search
  for variation of the fine structure constant

abstract:
  Relativistic energy shifts of the low energy levels of Fe have been
calculated using the Dirac-Hartree-Fock and configuration interaction
techniques. The results are to be used in the search for the space-time
variation of the fine structure constant in quasar absorption spectra. The
values of the shifts are the largest among those used in the analysis so far.
This makes Fe a good candidate for the inclusion into the analysis.


title:
How do diquark fluctuations and chiral soft modes affect di-lepton
  production in the deconfined phase?

abstract:
  We examine diquark fluctuations and chiral soft modes existing in the
precritical region of color superconductivity and chiral transition,
respectively, at finite temperature and density. We evaluate how they
contribute to anomalous di-lepton production; although there appear peaks in
the spectral function owing to the existence of the soft modes, the enhancement
of the production rate may not be so prominent to be a clear signal of the
phsase transitions.


title: Nanomechanical Spin-Polarizer

abstract:
  Torsional oscillations of a free-standing semiconductor beam are shown to
cause spin-dependent oscillating potentials that spin-polarize an applied
charge current in the presence of intentional or disorder scattering
potentials. We propose several realizations of mechanical spin generators and
manipulators based on this piezo-spintronic effect.


title: The clustering of SDSS galaxy groups: mass and color dependence

abstract:
  We use a sample of galaxy groups selected from the SDSS DR 4 with an adaptive
halo-based group finder to probe how the clustering strength of groups depends
on their masses and colors. In particular, we determine the relative biases of
groups of different masses, as well as that of groups with the same mass but
with different colors. In agreement with previous studies, we find that more
massive groups are more strongly clustered, and the inferred mass dependence of
the halo bias is in good agreement with predictions for the $\Lambda$CDM
cosmology. Regarding the color dependence, we find that groups with red
centrals are more strongly clustered than groups of the same mass but with blue
centrals. Similar results are obtained when the color of a group is defined to
be the total color of its member galaxies. The color dependence is more
prominent in less massive groups and becomes insignificant in groups with
masses $\gta 10^{14}\msunh$. We construct a mock galaxy redshift survey
constructed from the large Millenium simulation that is populated with galaxies
according to the semi-analytical model of Croton et al. Applying our group
finder to this mock survey, and analyzing the mock data in exactly the same way
as the true data, we are able to accurately recover the intrinsic mass and
color dependencies of the halo bias in the model. This suggests that our group
finding algorithm and our method of assigning group masses do not induce
spurious mass and/or color dependencies in the group-galaxy correlation
function. The semi-analytical model reveals the same color dependence of the
halo bias as we find in our group catalogue. In halos with $M\sim
10^{12}\msunh$, though, the strength of the color dependence is much stronger
in the model than in the data.


title:
Generalized Christoffel-Darboux formula for classical skew-orthogonal
  polynomials

abstract:
  We show that skew-orthogonal functions, defined with respect to Jacobi weight
$w_{a,b}(x)={(1-x)}^a{(1+x)}^b$, $a$, $b>-1$, including the limiting cases of
Laguerre ($w_{a}(x)=x^{a}e^{-x}$, $a > -1$) and Gaussian weight
($w(x)=e^{-x^2}$), satisfy three-term recursion relation in the quaternion
space. From this, we derive generalized Christoffel-Darboux (GCD) formul\ae\
for kernel functions arising in the study of the corresponding orthogonal and
symplectic ensembles of random $2N\times 2N$ matrices. Using the GCD formul\ae
we calculate the level-densities and prove that in the bulk of the spectrum,
under appropriate scaling, the eigenvalue correlations are universal. We also
provide evidence to show that there exists a mapping between skew-orthogonal
functions arising in the study of orthogonal and symplectic ensembles of random
matrices.


title: The Architecture of a Novel Weighted Network: Knowledge Network

abstract:
  Networked structure emerged from a wide range of fields such as biological
systems, World Wide Web and technological infrastructure. A deeply insight into
the topological complexity of these networks has been gained. Some works start
to pay attention to the weighted network, like the world-wide airport network
and the collaboration network, where links are not binary, but have
intensities. Here, we construct a novel knowledge network, through which we
take the first step to uncover the topological structure of the knowledge
system. Furthermore, the network is extended to the weighted one by assigning
weights to the edges. Thus, we also investigate the relationship between the
intensity of edges and the topological structure. These results provide a novel
description to understand the hierarchies and organizational principles in
knowledge system, and the interaction between the intensity of edges and
topological structure. This system also provides a good paradigm to study
weighted networks.


title: The stability and free expansion of a dipolar Fermi gas

abstract:
  We investigate the stability and the free expansion of a trapped dipolar
Fermi gas. We show that stabilizing the system relying on tuning the trap
geometry is generally inefficient. We further show that the expanded density
profile always gets stretched along the attractive direction of dipolar
interaction. We also point out that by switching off the dipolar interaction
simultaneously with the trapping potential, the deformation of momentum
distribution can be directly observed.


title: Translating solitons to symplectic and Lagrangian mean curvature flows

abstract:
  In this paper, we construct finite blow-up examples for symplectic mean
curvature flows and we study properties of symplectic translating solitons. We
prove that, the K\"ahler angle $\alpha$ of a symplectic translating soliton
with $\max |A|=1$ satisfies that $\sup |\alpha|>\frac{\pi}{4}\frac{|T|}{|T|+1}$
where $T$ is the direction in which the surface transltes.


title: Tate-Shafarevich groups and K3 surfaces

abstract:
  Following (and elaborating on) a method of Logan and van Luijk, we exhibit
explicit genus-2 curves whose Jacobians have nontrivial 2-torsion in their
Tate-Shafarevich groups.


title: Weierstrass's criterion and compact solitary waves

abstract:
  Weierstrass's theory is a standard qualitative tool for single degree of
freedom equations, used in classical mechanics and in many textbooks. In this
Brief Report we show how a simple generalization of this tool makes it possible
to identify some differential equations for which compact and even semicompact
traveling solitary waves exist. In the framework of continuum mechanics, these
differential equations correspond to bulk shear waves for a special class of
constitutive laws.


title:
Acoustic waves at the interface of a pre-stressed incompressible elastic
  solid and a viscous fluid

abstract:
  We analyse the influence of pre-stress on the propagation of interfacial
waves along the boundary of an incompressible hyperelastic half-space that is
in contact with a viscous fluid extending to infinity in the adjoining
half-space. One aim is to derive rigorously the incremental boundary conditions
at the interface; this derivation is delicate because of the interplay between
the Lagrangian and the Eulerian descriptions but is crucial for numerous
problems concerned with the interaction between a compliant wall and a viscous
fluid. A second aim of this work is to model the ultrasonic waves used in the
assessment of aortic aneurysms, and here we find that for this purpose the
half-space idealization is justified at high frequencies. A third goal is to
shed some light on the stability behaviour in compression of the solid
half-space, as compared with the situation in the absence of fluid; we find
that the usual technique of seeking standing waves solutions is not appropriate
when the half-space is in contact with a fluid; in fact, a correct analysis
reveals that the presence of a viscous fluid makes a compressed neo-Hookean
half-space slightly more stable. For a wave travelling in a direction of
principal strain, we obtain results for the case of a general (incompressible
isotropic) strain-energy function. For a wave travelling parallel to the
interface and in an arbitrary direction in a plane of principal strain, we
specialize the analysis to the neo-Hookean strain-energy function.


title: Piezoelectric Love waves on rotated Y-cut mm2 substrates

abstract:
  Consider a layer made of a m3m insulator crystal, with faces cut parallel to
a symmetry plane. Then bond it onto a semi-infinite mm2 piezoelectric
substrate. For a X- or Y -cut of the substrate, a Love wave can propagate in
the resulting structure and the corresponding dispersion equation is derived
analytically. It turns out that a fully explicit treatment can also be
conducted in the case of a Y -cut rotated about Z. In the case of a germanium
layer over a potassium niobate substrate, the wave exists at any wavelength for
X- and Y -cuts but this ceases to be the case for rotated cuts, with the
appearance of forbidden ranges. By playing on the cut angle, the Love wave can
be made to travel faster than, or slower than, or at the same speed as, the
shear bulk wave of the layer. A by-product of the analysis is the derivation of
the explicit secular equation for the Bleustein-Gulyaev wave in the substrate
alone, which corresponds to an asymptotic behavior of the Love wave.


title:
Holomorphic functions and regular quaternionic functions on the
  hyperk\"ahler space H

abstract:
  Let H be the space of quaternions, with its standard hypercomplex structure.
Let R(D) be the module of regular functions on D. For every unitary vector p in
S^2, R(D) contains the space of holomorphic functions w.r.t. the complex
structure J_p induced by p. We prove the existence, on any bounded domain D, of
regular functions that are not J_p-holomorphic for any p. Our starting point is
a result of Chen and Li concerning maps between hyperkaehler manifolds, where a
similar result is obtained for a less restricted class of quaternionic maps. We
give a criterion, based on the energy-minimizing property of holomorphic maps,
that distinguishes J_p-holomorphic functions among regular functions.


title: Bleustein-Gulyaev waves in some functionally graded materials

abstract:
  Functionally Graded Materials are inhomogeneous elastic bodies whose
properties vary continuously with space. Hence consider a half-space (x_2>0)
occupied by a special Functionally Graded Material made of an hexagonal (6 mm)
piezoelectric crystal for which the elastic stiffness c44, the piezoelectric
constant e15, the dielectric constant epsilon11, and the mass density, all vary
proportionally to the same "inhomogeneity function" f(x_2), say. Then consider
the problem of a piezoacoustic shear-horizontal surface wave which leaves the
interface (x_2=0) free of mechanical tractions and vanishes as x_2 goes to
infinity (the Bleustein-Gulyaev wave). It turns out that for some choices of
the function f, this problem can be solved exactly for the usual boundary
conditions, such as metalized surface or free surface. Several such functions
f(x_2) are derived here, such as exp($\pm 2\beta x_2) (\beta is a constant)
which is often encountered in geophysics, or other functions which are periodic
or which vanish as x_2 tends to infinity; one final example presents the
advantage of describing a layered half-space which becomes asymptotically
homogeneous away from the interface. Special attention is given to the
influence of the different inhomogeneity functions upon the characteristics of
the Bleustein-Gulyaev wave (speed, dispersion, attenuation factors, depth
profiles, electromechanical coupling factor, etc.)


title:
Recurrent extensions of self-similar Markov processes and Cram\'er's
  condition II

abstract:
  We prove that a positive self-similar Markov process $(X,\mathbb{P})$ that
hits 0 in a finite time admits a self-similar recurrent extension that leaves 0
continuously if and only if the underlying L\'{e}vy process satisfies
Cram\'{e}r's condition.


title: Nuclear effects in F_3 structure function of nucleon

abstract:
  We study nuclear effects in the $F^A_3(x)$ structure function in the deep
inelastic neutrino reactions on iron by using a relativistic framework to
describe the nucleon spectral functions in the nucleus.
  The results for the ratio $R(x,Q^2)=\frac{F^A_3(x,Q^2)}{AF^N_3(x, Q^2)}$ and
the Gross-Llewellyn Smith(GLS) integral $G(x,Q^2)=\int_x^1 dx F^A_3(x,Q^2)$ in
nuclei are discussed and compared with the recent results available in
literature from theoretical and phenomenological analyses of experimental data.


title:
Building the Tangent and Adjoint codes of the Ocean General Circulation
  Model OPA with the Automatic Differentiation tool TAPENADE

abstract:
  The ocean general circulation model OPA is developed by the LODYC team at
Paris VI university. OPA has recently undergone a major rewriting, migrating to
FORTRAN95, and its adjoint code needs to be rebuilt. For earlier versions, the
adjoint of OPA was written by hand at a high development cost. We use the
Automatic Differentiation tool TAPENADE to build mechanicaly the tangent and
adjoint codes of OPA. We validate the differentiated codes by comparison with
divided differences, and also with an identical twin experiment. We apply
state-of-the-art methods to improve the performance of the adjoint code. In
particular we implement the Griewank and Walther's binomial checkpointing
algorithm which gives us an optimal trade-off between time and memory
consumption. We apply a specific strategy to differentiate the iterative linear
solver that comes from the implicit time stepping scheme


title:
Two-mode Bose-Einstein condensate in a high-frequency driving field that
  directly couples the two modes

abstract:
  A two-mode Bose-Einstein condensate coupled by a high-frequency modulation
field is found to display rich features. An effective stationary Hamiltonian
approach reveals the emergence of additional degenerate eigenstates as well as
new topological structures of the spectrum. Possible applications, such as the
suppression of nonlinear Landau-Zener tunneling, are discussed. An interesting
phenomenon, which we call "deterministic symmetry-breaking trapping" associated
with separatrix crossing, is also found in an adiabatic process.


title: Quasi-bound states of quantum dots in single and bilayer graphene

abstract:
  Dirac fermions interacting with a cylindrically symmetric quantum dot
potential created in single and bilayer graphene are not confined but form
quasi-bound states. The broadening of these quasi-bound states (i. e. the
inverse of their lifetimes) decreases (increases) with the orbital momentum of
the electron in the case of graphene (bilayer). Quasi-bound states with energy
below (above) the barrier height are dominantly electron(hole)-like. A
remarkable decrease of the energy level broadening is predicted for electron
energies close to the barrier height, which are a consequence of the total
internal reflection of the electronic wave at the dot edge.


title: On the symmetric square. Unstable Twisted Characters

abstract:
  We provide a purely local computation of the (elliptic) twisted (by
"transpose-inverse") character of the representation \pi=I(\1) of PGL(3) over a
p-adic field induced from the trivial representation of the maximal parabolic
subgroup. This computation is independent of the theory of the symmetric square
lifting of [IV] of automorphic and admissible representations of SL(2) to
PGL(3). It leads to a proof of the (unstable) fundamental lemma in the theory
of the symmetric square lifting, namely that corresponding spherical functions
(on PGL(2) and PGL(3)) are matching: they have matching orbital integrals.


title: Natural mu and Bmu in gauge mediation

abstract:
  We propose a natural solution to the mu problem in gauge mediation. It relies
on the logarithmic dependence of the effective Kahler potential on the
messenger threshold superfield X. Thus, mu and Bmu naturally arise at one and
two loops, respectively. Moreover B has the same phase as the gaugino mass and
the supersymmetric CP problem is solved as well.


title: Fitting function for asymmetric peaks

abstract:
  In the paper a new fitting function is suggested, which can essentially
increase the existing instrumentation for fitting of asymmetric peaks with the
only maximum.


title: Uniformization of \mathcal{G}-bundles

abstract:
  We show some of the conjectures of Pappas and Rapoport concerning the moduli
stack of $\mathcal{G}$-torsors on a curve C, where $\mathcal{G}$ is a
semisimple Bruhat-Tits group scheme on C. In particular we prove the analog of
the uniformization theorem of Drinfeld-Simpson in this setting. Furthermore we
apply this to compute the connected components of these moduli stacks and to
calculate the Picard group of the stack of torsors in case $\mathcal{G}$ is
simply connected.


title: Fundamental properties of low-mass stars

abstract:
  Numerous investigations on the fundamental properties of low-mass stars using
eclipsing binaries indicate a strong discrepancy between theory and
observations that is still awaiting explanation. Current models seem to predict
radii for stars less massive than the Sun that are some 10% smaller than
observed, while their effective temperatures are some 5% larger. Here we
discuss recent new observational data that are relevant to this issue and
review the progress made in understanding the origin of the important
differences with theoretical calculations. Notably, we provide evidence that
stellar activity may be responsible for the mismatch between observations and
theory through two different channels: inhibition of convection or effects of a
significant starspot coverage. The activity hypothesis is put to a test with
observational diagnostics and some of the consequences of the large starspot
coverage are evaluated. We conclude that stellar activity likely plays a key
role in defining the properties of active low-mass stars and that this should
be properly taken into account when investigating young, active stars in
clusters or star-forming regions.


title: Covariance and PCA for Categorical Variables

abstract:
  Covariances from categorical variables are defined using a regular simplex
expression for categories. The method follows the variance definition by Gini,
and it gives the covariance as a solution of simultaneous equations. The
calculated results give reasonable values for test data. A method of principal
component analysis (RS-PCA) is also proposed using regular simplex expressions,
which allows easy interpretation of the principal components. The proposed
methods apply to variable selection problem of categorical data USCensus1990
data. The proposed methods give appropriate criterion for the variable
selection problem of categorical


title: Singular elliptic genus of normal surfaces

abstract:
  We define the singular elliptic genus for arbitrary normal surfaces, prove
that it is a birational invariant, and show that it generalizes the singular
elliptic genus of Borisov and Libgober and the stringy $\chi_y$ genus of
Batyrev and Veys.


title: Non-LTE line formation for heavy elements in four very metal-poor stars

abstract:
  Stellar parameters and abundances of Na, Mg, Al, K, Ca, Sr, Ba, and Eu are
determined for four very metal-poor stars (-2.66 < [Fe/H] < -2.15) based on
non-LTE line formation and analysis of high-resolution (R ~60000 and 90000)
high signal-to-noise (S/N > 200) observed spectra. A model atom for H I is
presented. An effective temperature was obtained from the Balmer Halpha and
Hbeta line wing fits, the surface gravity from the Hipparcos parallax if
available and the non-LTE ionization balance between Ca I and Ca II. Based on
the hyperfine structure affecting the Ba II resonance line, the fractional
abundance of the odd isotopes of Ba was derived for HD 84937 and HD 122563 from
a requirement that Ba abundances from the resonance line and subordinate lines
of Ba II must be equal. For each star, non-LTE leads to a consistency of Teff
from two Balmer lines and to a higher temperature compared to the LTE case, by
up to 60 K. Non-LTE effects are important in spectroscopic determination of
surface gravity from Ca I/Ca II. For each star with a known trigonometric
gravity, non-LTE abundances from the lines of two ionization stages agree
within the error bars, while a difference in the LTE abundances consists of
0.23 dex to 0.40 dex for different stars. Departures from LTE are found to be
significant for the investigated atoms, and they strongly depend on stellar
parameters. For HD 84937, the Eu/Ba ratio is consistent with the relative solar
system r-process abundances, and the fraction of the odd isotopes of Ba, f_odd,
equals 0.43+-0.14. The latter can serve as a constraint on r-process models.
The lower Eu/Ba ratio and f_odd = 0.22+-0.15 found for HD 122563 suggest that
the s-process or the unknown process has contributed significantly to the Ba
abundance in this star.


title:
Long standing problem of 210Bi and the realistic neutron-proton
  effective interaction

abstract:
  The odd-odd nucleus 210Bi is studied within the framework of the shell model
using effective two-body matrix elements derived from the CD-Bonn
nucleon-nucleon potential. The experimental energies of the proton-neutron
multiplet ph9/2 ng9/2 are remarkably well reproduced by the theory, which
accounts for the 1- state being the ground state instead of the 0- predicted by
the Nordheim strong coupling rule. It is shown that the core-polarization
effects are crucial to produce this inversion. The similarity between
neutron-proton multiplets in the 132Sn and 208Pb regions is discussed in
connection with the effective interaction.


title: A Direct Proof of the Theorem on Formal Functions

abstract:
  We give a direct and elementary proof of the theorem on formal functions by
studying the behaviour of the Godement resolution of a sheaf of modules under
completion.


title:
Bounds for the covariance of functions of infinite variance stable
  random variables with applications to central limit theorems and
  wavelet-based estimation

abstract:
  We establish bounds for the covariance of a large class of functions of
infinite variance stable random variables, including unbounded functions such
as the power function and the logarithm. These bounds involve measures of
dependence between the stable variables, some of which are new. The bounds are
also used to deduce the central limit theorem for unbounded functions of stable
moving average time series. This result extends the earlier results of Tailen
Hsing and the authors on central limit theorems for bounded functions of stable
moving averages. It can be used to show asymptotic normality of wavelet-based
estimators of the self-similarity parameter in fractional stable motions.