title:
The photometric evolution of star clusters and the preferential loss of
  low-mass bodies - with an application to globular clusters

abstract:
  To obtain an accurate description of broad-band photometric star cluster
evolution, certain effects should be accounted for, such as the preferential
loss of low-mass stars and the retain of stellar remnants. Moreover, the IMF
and metallicity affect photometry as well. Due to their advanced evolutionary
state, globular clusters (GCs) are interesting test cases for cluster models
describing these effects. In this paper we describe cluster models in which the
above effects are included. The photometric evolution of clusters is predicted,
and the results are applied to Galactic GCs. The presented cluster models
represent an analytical description of the evolution of the underlying stellar
mass function due to stellar evolution and dynamical cluster dissolution.
Stellar remnants are included by using initial-remnant mass relations, while
cluster photometry is computed from the Padova 1999 isochrones. Our study shows
that the preferential loss of low-mass stars, the retain of stellar remnants,
as well as IMF and metallicity variations strongly influence the magnitude,
colour and mass-to-light ratio evolution of clusters. The different effects can
be clearly separated with our models. The models are applied to the Galactic GC
population, of which the magnitude, colour and mass-to-light ratio ranges are
well reproduced. We also show that the mass-to-light ratios of clusters of
similar ages and metallicities cannot be assumed to be constant for all cluster
luminosities. Instead, mass-to-light ratio increases with cluster luminosity
and mass. These models underline the importance of detailed cluster models when
considering cluster photometry. With the analytic framework provided in this
paper, observed cluster properties can be interpreted in a more complete
perspective. (Abridged)


title: Issues in joint SZ and optical cluster finding

abstract:
  We apply simple optical and SZ cluster finders to mock galaxy catalogues and
SZ flux maps created from dark matter halos in a (1 Gpc/h)^3 dark matter
simulation, at redshifts 0.5 and 0.9. At each redshift, the two catalogues are
then combined to assess how well they can improve each other, and compared to
several variants of catalogues made using SZ flux and galaxy information
simultaneously. We use several different criteria to compare the catalogues,
and illustrate some of the tradeoffs which arise in tuning the galaxy cluster
finders with respect to these criteria. We detail many of the resulting
improvements and issues which arise in comparing and combining these two types
of data sets.


title: AGN Host Galaxy Morphologies in COSMOS

abstract:
  We use HST/ACS images and a photometric catalog of the COSMOS field to
analyze morphologies of the host galaxies of approximately 400 AGN candidates
at redshifts 0.3 < z < 1.0. We compare the AGN hosts with a sample of
non-active galaxies drawn from the COSMOS field to match the magnitude and
redshift distribution of the AGN hosts. We perform 2-D surface brightness
modeling with GALFIT to yield host galaxy and nuclear point source magnitudes.
X-ray selected AGN host galaxy morphologies span a substantial range that peaks
between those of early-type, bulge-dominated and late-type, disk-dominated
systems. We also measure the asymmetry and concentration of the host galaxies.
Unaccounted for, the nuclear point source can significantly bias results of
these measured structural parameters, so we subtract the best-fit point source
component to obtain images of the underlying host galaxies. Our concentration
measurements reinforce the findings of our 2-D morphology fits, placing X-ray
AGN hosts between early- and late-type inactive galaxies. AGN host asymmetry
distributions are consistent with those of control galaxies. Combined with a
lack of excess companion galaxies around AGN, the asymmetry distributions
indicate that strong interactions are no more prevalent among AGN than normal
galaxies. In light of recent work, these results suggest that the host galaxies
of AGN at these X-ray luminosities may be in a transition from disk-dominated
to bulge-dominated, but that this transition is not typically triggered by
major mergers.


title: Galactic dynamo action in presence of stochastic alpha and shear

abstract:
  Using a one-dimensional $\alpha\omega$-dynamo model appropriate to galaxies,
we study the possibility of dynamo action driven by a stochastic alpha effect
and shear. To determine the field evolution, one needs to examine a large
number of different realizations of the stochastic component of $\alpha$. The
net growth or decay of the field depends not only on the dynamo parameters but
also on the particular realization, the correlation time of the stochastic
$\alpha$ compared to turbulent diffusion timescale and the time over which the
system is evolved. For dynamos where both a coherent and fluctuating $\alpha$
are present, the stochasticity of $\alpha$ can help alleviate catastrophic
dynamo quenching, even in the absence of helicity fluxes. One can obtain final
field strengths up to a fraction $\sim 0.01$ of the equipartition field $
B_{eq}$ for dynamo numbers $| D| \sim 40$, while fields comparable to $ B_{eq}$
require much larger degree of $\alpha$ fluctuations or shear. This type of
dynamo may be particularly useful for amplifying fields in the central regions
of disk galaxies.


title: Massive black hole binary mergers within sub-pc scale gas discs

abstract:
  [ABRIDGED] We study supermassive black hole binary mergers driven by angular
momentum loss to small-scale gas discs. Such binaries form after major galaxy
mergers, but their fate is unclear since hardening through stellar scattering
becomes very inefficient at sub-parsec distances. Gas discs may dominate binary
dynamics on these scales, and promote mergers. Using numerical simulations, we
investigate the evolution of the orbits of binaries embedded within
geometrically thin gas discs. Our simulations directly resolve angular momentum
transport within the disc, which at the radii of interest is likely dominated
by disc self-gravity. We show that the binary decays at a rate which is in good
agreement with analytical estimates, while the eccentricity grows. Saturation
of eccentricity growth is not observed up to values e > 0.35. Accretion onto
the black holes is variable, and is roughly modulated by the binary orbital
frequency. Scaling our results, we analytically estimate the maximum rate of
binary decay that is possible without fragmentation occuring within the
surrounding gas disc, and compare that rate to an estimate of the stellar
dynamical hardening rate. For binary masses in the range 10^5 < M/Msun < 10^8
we find that decay due to gas discs may dominate for separations below a ~
0.01--0.1 pc, where the disc is optically thick. The minimum merger time scale
is shorter than the Hubble time for M < 10^7 Msun. This implies that gas discs
could commonly attend relatively low mass black hole mergers, and that a
significant population of binaries might exist at separations of a few
hundredths of a pc, where the combined decay rate is slowest. For more massive
binaries, we suggest that scattering of stars formed within a fragmenting gas
disc could act as a significant additional sink of binary angular momentum.


title:
Probing spatial spin correlations of ultracold gases by quantum noise
  spectroscopy

abstract:
  Spin noise spectroscopy with a single laser beam is demonstrated
theoretically to provide a direct probe of the spatial correlations of cold
fermionic gases. We show how the generic many-body phenomena of anti-bunching,
pairing, antiferromagnetic, and algebraic spin liquid correlations can be
revealed by measuring the spin noise as a function of laser width, temperature,
and frequency.


title:
A Derivation of the Luminosity Function of the Kuiper Belt from a Broken
  Power-Law Size Distribution

abstract:
  We have derived a model of the Kuiper belt luminosity function exhibited by a
broken power-law size distribution. This model allows direct comparison of the
observed luminosity function to the underlying size distribution. We discuss
the importance of the radial distribution model in determining the break
diameter. We determine a best-fit break-diameter of the Kuiper belt
size-distribution of 30<Db<90 km via a maximum-likelihood fit of our model to
the observed luminosity function. We also confirm that the observed luminosity
function for m(R) ~ 21-28 is consistent with a broken power-law size
distribution, and exhibits a break at m(R)=26.0+0.7-1.8.


title: The Deep SWIRE Field I. 20cm Continuum Radio Observations: A Crowded Sky

abstract:
  We present results from deep radio observations taken with the VLA at a
center frequency of 1400 MHz cover a region of the SWIRE Spitzer Legacy survey,
centered at 10 46 00, 59 01 00 (J2000). The reduction and cataloging of the
radio sources are described. The survey presented is the deepest so far in
terms of the radio source density on the sky. Perhaps surprisingly, the sources
down to the bottom of the catalog have median angular sizes greater than 1
arcsecond, like their cousins 10-100 times stronger. If the log N - log S
normalization remains constant at the lowest flux densities, there are about 6
sources per square arcminute down to 15 microJy at 20cm. Given the finite
source sizes this implies we may reach the natural confusion limit near 1
microJy.


title:
Proper Motions of Thermal Radio Sources near HH 7-11 in the NGC 1333
  Star Forming Region

abstract:
  Star forming regions are expected to show linear proper motions due to the
relative motion of the Sun with respect to the region. These proper motions
appear superposed to the proper motions expected in features associated with
mass ejection from the young stellar objects embedded in them. Therefore, it is
necessary to have a good knowledge of the proper motions of the region as a
whole in order to correctly interpret the motions associated with mass
ejection. In this paper we present the first direct measurement of proper
motions of the NGC 1333 star forming region. This region harbors one of the
most studied Herbig-Haro systems, HH 7-11, whose exciting source remains
unclear. Using VLA A configuration data at 3.6 cm taken over 10 years, we have
been able to measure the absolute proper motions of four thermal sources
embedded in NGC 1333. From our results we have derived the mean proper motions
of the NGC 1333 star forming region to be mu(alpha)cos(delta) = 9 +- 1 mas/yr
and mu(delta) = -10 +- 2 mas/yr. In this paper, we also discuss the possible
implications of our results in the identification of the outflow exciting
sources.


title: [NeII] emission line profiles from photoevaporative disc winds

abstract:
  I model profiles of the [NeII] forbidden emission line at 12.81um, emitted by
photoevaporative winds from discs around young, solar-mass stars. The predicted
line luminosities (~ 1E-6 Lsun) are consistent with recent data, and the line
profiles vary significantly with disc inclination. Edge-on discs show broad
(30-40km/s) double-peaked profiles, due to the rotation of the disc, while in
face-on discs the structure of the wind results in a narrower line (~10km/s)
and a significant blue-shift (5-10km/s). These results suggest that
observations of [NeII] line profiles can provide a direct test of models of
protoplanetary disc photoevaporation.


title:
Atomic diffusion and mixing in old stars II. Observations of stars in
  the globular cluster NGC 6397 with VLT/FLAMES-GIRAFFE

abstract:
  Evolutionary trends in the surface abundances of heavier elements have
recently been identified in the globular cluster NGC 6397 ([Fe/H]=-2),
indicating the operation of atomic diffusion in these stars. Such trends
constitute important constraints for the extent to which diffusion modifies the
internal structure and surface abundances of solar-type, metal-poor stars. We
perform an independent check of the reality and size of abundance variations
within this metal-poor globular cluster. Observational data covering a large
stellar sample, located between the cluster turn-off point and the base of the
red giant branch, are homogeneously analysed. The spectroscopic data were
obtained with the medium-high resolution spectrograph FLAMES/GIRAFFE on
VLT-UT2. We derive independent effective-temperature scales from profile
fitting of Balmer lines and by applying colour-temperature calibrations to
Str\"omgren uvby and broad-band BVI photometry. An automated spectral analysis
code is used together with a grid of MARCS model atmospheres to derive stellar
surface abundances of Mg, Ca, Ti, and Fe. We identify systematically higher
iron abundances for more evolved stars. The turn-off point stars are found to
have 0.13dex lower surface abundances of iron compared to the coolest, most
evolved stars in our sample. There is a strong indication of a similar trend in
magnesium, whereas calcium and titanium abundances are more homogeneous. Within
reasonable error limits, the obtained abundance trends are in agreement with
the predictions of stellar structure models including diffusive processes
(sedimentation, levitation), if additional turbulent mixing below the outer
convection zone is included.


title:
Superfield actions for N=8 and N=6 conformal theories in three
  dimensions

abstract:
  The manifestly supersymmetric pure spinor formulations of the
Bagger-Lambert-Gustavsson models with N=8 supersymmetry and the
Aharony-Bergman-Jafferis-Maldacena models with N=6 supersymmetry are given. The
structures of the pure spinors are investigated in both cases, and
non-degenerate measures are formed using non-minimal sets of variables,
allowing for the formulation of an action principle.


title:
A moving boundary problem motivated by electric breakdown: I. Spectrum
  of linear perturbations

abstract:
  An interfacial approximation of the streamer stage in the evolution of sparks
and lightning can be written as a Laplacian growth model regularized by a
`kinetic undercooling' boundary condition. We study the linear stability of
uniformly translating circles that solve the problem in two dimensions. In a
space of smooth perturbations of the circular shape, the stability operator is
found to have a pure point spectrum. Except for the zero eigenvalue for
infinitesimal translations, all eigenvalues are shown to have negative real
part. Therefore perturbations decay exponentially in time. We calculate the
spectrum through a combination of asymptotic and series evaluation. In the
limit of vanishing regularization parameter, all eigenvalues are found to
approach zero in a singular fashion, and this asymptotic behavior is worked out
in detail. A consideration of the eigenfunctions indicates that a strong
intermediate growth may occur for generic initial perturbations. Both the
linear and the nonlinear initial value problem are considered in a second
paper.


title:
Fluctuations of the quenched mean of a planar random walk in an i.i.d.
  random environment with forbidden direction

abstract:
  We consider an i.i.d. random environment with a strong form of transience on
the two dimensional integer lattice. Namely, the walk always moves forward in
the y-direction. We prove a functional CLT for the quenched expected position
of the random walk indexed by its level crossing times. We begin with a
variation of the Martingale Central Limit Theorem. The main part of the paper
checks the conditions of the theorem for our problem.


title: Entanglement of formation for an arbitrary two-mode Gaussian state

abstract:
  We write the optimal pure-state decomposition of any two-mode Gaussian state
and show that its entanglement of formation coincides with the Gaussian one.
This enables us to develop an insightful approach of evaluating the exact
entanglement of formation. Its additivity is finally proven.


title: Bellman Function and the $H^1-BMO$ Duality

abstract:
  A Bellman function approach to Fefferman's $H^1-BMO$ duality theorem is
presented. One Bellman-type argument is used to handle two different
one-dimensional cases, dyadic and continuous. An explicit estimate for the
constant of embedding $BMO\subset (H^1)^*$ is given in the dyadic case. The
same Bellman function is then used to establish a multi-dimensional analog.


title: Arithmetic aspects of self-similar groups

abstract:
  We prove that an irreducible lattice in a semisimple algebraic group is
virtually isomorphic to an arithmetic lattice if and only if it admits a
faithful self-similar action on a rooted tree of finite valency.


title:
Theoretical investigation of synchronous totally asymmetric exclusion
  processes on lattices with multiple-input-single-output junctions

abstract:
  In this paper, we investigate the dynamics of synchronous totally asymmetric
exclusion processes on lattices with a multiple-input single-output (MISO)
junction, which consists of m subchains for the input and one main chain for
the output. A MISO junction is a type of complex geometry that is relevant to
many biological processes as well as vehicular and pedestrian traffic flow. A
mean-field approach is developed to deal with the junction that connects the
subchains and the main chain. Theoretical results for stationary particle
currents, density profiles, and a phase diagram have been obtained. It is found
that the phase boundary moves toward the left in the phase diagram with an
increase of the number of subchains. The nonequilibrium stationary states,
stationary-state phases, and phase boundaries are determined by the boundary
conditions of the system as well as by the number of subchains. The density
profiles obtained from computer simulations show very good agreement with our
theoretical analysis.


title: Quadrivariate existence theorems and strong representability

abstract:
  In this paper, we give conditions under which we can compute the conjugate of
a convex function on the product of two Frechet spaces defined in terms of
another convex function on the product of two (possibly different) Frechet
spaces. We use this result to give simple proofs of some (both old and new)
results for Banach spaces, and deduce some (both old and new) stability results
for strongly representable multifunctions. We take as our starting point a
result on closed convex cones in the product of two Frechet spaces.


title: Nondeterministic Noiseless Linear Amplification of Quantum Systems

abstract:
  We introduce the concept of non-deterministic noiseless linear amplification.
We propose a linear optical realization of this transformation that could be
built with current technology. We discuss two applications; ideal probabilistic
cloning of coherent states and distillation of continuous variable
entanglement. For the latter example we demonstrate that highly pure
entanglement can be distilled from transmission over a lossy channel.


title:
AAOmega radial velocities rule out current membership of the planetary
  nebula NGC 2438 in the open cluster M46

abstract:
  We present new radial velocity measurements of 586 stars in a one-degree
field centered on the open cluster M46, and the planetary nebula NGC 2438
located within a nuclear radius of the cluster. The data are based on
medium-resolution optical and near-infrared spectra taken with the AAOmega
spectrograph on the Anglo-Australian Telescope. We find a velocity difference
of about 30 km/s between the cluster and the nebula, thus removing all
ambiguities about the cluster membership of the planetary nebula caused by
contradicting results in the literature. The line-of-sight velocity dispersion
of the cluster is 3.9+/-0.3 km/s, likely to be affected by a significant
population of binary stars.


title: Yang-Mills Theory in Twistor Space

abstract:
  This thesis carries out a detailed investigation of the action for pure Yang-
Mills theory which L. Mason formulated in twistor space. The rich structure of
twistor space results in greater gauge freedom compared to the theory in
ordinary space-time. One particular gauge choice, the CSW gauge, allows
simplifications to be made at both the classical and quantum level.
  The equations of motion have an interesting form in the CSW gauge, which
suggests a possible solution procedure. This is explored in three special
cases. Explicit solutions are found in each case and connections with earlier
work are examined. The equations are then reformulated in Minkowski space, in
order to deal with an initial-value, rather than boundary-value, problem. An
interesting form of the Yang-Mills equation is obtained, for which we propose
an iteration procedure.
  The quantum theory is also simplified by adopting the CSW gauge. The Feynman
rules are derived and are shown to reproduce the MHV diagram formalism
straightforwardly, once LSZ reduction is taken into account. The three-point
amplitude missing in the MHV formalism can be recovered in our theory. Finally,
relations to Mansfield's canonical transformation approach are elucidated.


title:
The Evolution of Galaxy Disks in Dense Environments - Lessons from
  Compact Galaxy Groups

abstract:
  Disk galaxies in compact galaxy groups exhibit a remarkable shortfall of
neutral hydrogen compared to both isolated spirals and spirals in more loose
groups, but the origin of this HI deficiency remains unclear. Based on a sample
of highly HI deficient compact galaxy groups, here updated to also include HCG
58 and HCG 93, we summarise the first results of a multi-wavelength campaign
aimed at understanding the processes responsible for modifying the HI content
of galaxy disks in these environments. While tidal stripping, ram pressure
stripping by hot intragroup gas, and star-formation induced strangulation could
individually be affecting the ISM in some of the group members, these processes
each face specific difficulties in explaining the inferred deficiency of HI for
the sample as a whole. A complete picture of the mechanisms driving the ISM
evolution in the disk galaxies of these groups has thus yet to emerge, but
promising avenues for further progress in this field are briefly discussed on
the basis of the present sample.


title: On orbifolds and free fermion constructions

abstract:
  This work develops the correspondence between orbifolds and free fermion
models. A complete classification is obtained for orbifolds X/G with X the
product of three elliptic curves and G an abelian extension of a group (Z_2)^2
of twists acting on X. Each such quotient X/G is shown to give a geometric
interpretation to an appropriate free fermion model, including the geometric
NAHE+ model. However, the semi-realistic NAHE free fermion model is proved to
be non-geometric: its Hodge numbers are not reproduced by any orbifold X/G. In
particular cases it is shown that X/G can agree with some Borcea-Voisin
threefolds, an orbifold limit of the Schoen threefold, and several further
orbifolds thereof. This yields free fermion models with geometric
interpretations on such special threefolds.


title: Slope filtrations in families

abstract:
  This paper concerns arithmetic families of $\varphi$-modules over reduced
affinoid spaces. For such a family, we first prove that the slope polygons is
lower semicontinuous around any rigid point. If the slope polygons are locally
constant around a rigid point, we further prove that around this point, the
family has a global slope filtration after base change to some extended Robba
ring.


title: Dynamics of alliance formation and the egalitarian revolution

abstract:
  Arguably the most influential force in human history is the formation of
social coalitions and alliances (i.e., long-lasting coalitions) and their
impact on individual power. In most great ape species, coalitions occur at
individual and group levels and among both kin and non-kin. Nonetheless, ape
societies remain essentially hierarchical, and coalitions rarely weaken social
inequality. In contrast, human hunter-gatherers show a remarkable tendency to
egalitarianism, and human coalitions and alliances occur not only among
individuals and groups, but also among groups of groups. Here, we develop a
stochastic model describing the emergence of networks of allies resulting from
within-group competition for status or mates between individuals utilizing
dyadic information. The model shows that alliances often emerge in a phase
transition-like fashion if the group size, awareness, aggressiveness, and
persuasiveness of individuals are large and the decay rate of individual
affinities is small. With cultural inheritance of social networks, a single
leveling alliance including all group members can emerge in several
generations. Our results suggest that a rapid transition from a hierarchical
society of great apes to an egalitarian society of hunter-gatherers (often
referred to as "egalitarian revolution") could indeed follow an increase in
human cognitive abilities. The establishment of stable group-wide egalitarian
alliances creates conditions promoting the origin of cultural norms favoring
the group interests over those of individuals.


title:
Jitter radiation images, spectra, and light curves from a relativistic
  spherical blastwave

abstract:
  We consider radiation emitted by the jitter mechanism in a Blandford-McKee
self-similar blastwave. We assume the magnetic field configuration throughout
the whole blastwave meets the condition for the emission of jitter radiation
and we compute the ensuing images, light curves and spectra. The calculations
are performed for both a uniform and a wind environment. We compare our jitter
results to synchrotron results. We show that jitter radiation produces slightly
different spectra than synchrotron, in particular between the self-absorption
and the peak frequency, where the jitter spectrum is flat, while the
synchrotron spectrum grows as \nu^{1/3}. The spectral difference is reflected
in the early decay slope of the light curves. We conclude that jitter and
synchrotron afterglows can be distinguished from each other with good quality
observations. However, it is unlikely that the difference can explain the
peculiar behavior of several recent observations, such as flat X-ray slopes and
uncorrelated optical and X-ray behavior.


title:
Pressure gradients, shell crossing singularities and acoustic
  oscillations - application to inhomogeneous cosmological models

abstract:
  Inhomogeneous cosmological models have recently become a very interesting
alternative to standard cosmology. This is because these models are able to fit
cosmological observations without the need for dark energy. However, due to
inhomogeneity and pressure-less matter content, these models can suffer from
shell crossing singularities. These singularities occur when two shell of dust
collide with each other leading to infinite values of the density. In this
Letter we show that if inhomogeneous pressure is included then these
singularities can be prevented from occurring over the period of structure
formation. Thus, a simple incorporation of a gradient of pressure allows for
more comprehensive studies of inhomogeneous cosmological models and their
application to cosmology.


title: Synergetic Application, Equations on Rule of Law and Two-Party Mechanism

abstract:
  Based on the synergetic equations and its application, we propose the
equations on the rule of law. From these equations we may prove mathematically
that a society of the rule of law cannot lack any aspect for three types of the
legislation, the administration and the judicature. Otherwise, we propose an
equation of corruption, and discuss quantitatively some threshold values for a
system into corruption. Moreover, from synergetics we obtain the Lorenz model,
which may be a visualized two-party mechanism as a type of stable structure in
democracy. A developed direction of society should be the combination from
macroscopic to microscopic order, from an actual capable handling to an ideal
pursuance.


title: Ancilla-Assisted Discrimination of Quantum Gates

abstract:
  The intrinsic idea of superdense coding is to find as many gates as possible
such that they can be perfectly discriminated. In this paper, we consider a new
scheme of discrimination of quantum gates, called ancilla-assisted
discrimination, in which a set of quantum gates on a $d-$dimensional system are
perfectly discriminated with assistance from an $r-$dimensional ancilla system.
The main contribution of the present paper is two-fold: (1) The number of
quantum gates that can be discriminated in this scheme is evaluated. We prove
that any $rd+1$ quantum gates cannot be perfectly discriminated with assistance
from the ancilla, and there exist $rd$ quantum gates which can be perfectly
discriminated with assistance from the ancilla. (2) The dimensionality of the
minimal ancilla system is estimated. We prove that there exists a constant
positive number $c$ such that for any $k\leq cr$ quantum gates, if they are
$d$-assisted discriminable, then they are also $r$-assisted discriminable, and
there are $c^{\prime}r\textrm{}(c^{\prime}>c)$ different quantum gates which
can be discriminated with a $d-$dimensional ancilla, but they cannot be
discriminated if the ancilla is reduced to an $r-$dimensional system. Thus, the
order $O(r)$ of the number of quantum gates that can be discriminated with
assistance from an $r-$dimensional ancilla is optimal. The results reported in
this paper represent a preliminary step toward understanding the role ancilla
system plays in discrimination of quantum gates as well as the power and limit
of superdense coding.


title: User Guide for the Discrete Dipole Approximation Code DDSCAT 7.0

abstract:
  DDSCAT 7.0 is an open-source Fortran-90 software package applying the
discrete dipole approximation to calculate scattering and absorption of
electromagnetic waves by targets with arbitrary geometries and complex
refractive index. The targets may be isolated entities (e.g., dust particles),
but may also be 1-d or 2-d periodic arrays of "target unit cells", allowing
calculation of absorption, scattering, and electric fields around arrays of
nanostructures.
  The theory of the DDA and its implementation in DDSCAT is presented in Draine
(1988) and Draine & Flatau (1994), and its extension to periodic structures
(and near-field calculations) in Draine & Flatau (2008). DDSCAT 7.0 includes
support for MPI, OpenMP, and the Intel Math Kernel Library (MKL). DDSCAT
supports calculations for a variety of target geometries. Target materials may
be both inhomogeneous and anisotropic. It is straightforward for the user to
"import" arbitrary target geometries into the code. DDSCAT automatically
calculates total cross sections for absorption and scattering and selected
elements of the Mueller scattering intensity matrix.
  This User Guide explains how to use DDSCAT 7.0 to carry out electromagnetic
scattering calculations. DDfield, a Fortran-90 code DDfield to calculate E and
B at user-selected locations near the target, is included in the distribution.


title:
The discrete dipole approximation for periodic targets I. theory and
  tests

abstract:
  The discrete-dipole approximation (DDA) is a powerful method for calculating
absorption and scattering by targets that have sizes smaller than or comparable
to the wavelength of the incident radiation. The DDA can be extended to targets
that are singly- or doubly-periodic. We generalize the scattering amplitude
matrix and the 4 x 4 Mueller matrix to describe scattering by singly- and
doubly-periodic targets, and show how these matrices can be calculated using
the DDA. The accuracy of DDA calculations using the open-source code DDSCAT is
demonstrated by comparison to exact results for infinite cylinders and infinite
slabs. A method for using the DDA solution to obtain fields within and near the
target is presented, with results shown for infinite slabs.


title: The Cepheid Galactic Internet

abstract:
  We propose that a sufficiently advanced civilization may employ Cepheid
variable stars as beacons to transmit all-call information throughout the
galaxy and beyond. One can construct many scenarios wherein it would be
desirable for such a civilization of star ticklers to transmit data to anyone
else within viewing range. The beauty of employing Cepheids is that these stars
can be seen from afar(we monitor them out through the Virgo cluster), and any
developing technological society would seem to be likely to closely observe
them as distance markers. Records exist of Cepheids for well over one hundred
years. We propose that these (and other regularly variable types of stars) be
searched for signs of phase modulation (in the regime of short pulse duration)
and patterns, which could be indicative of intentional signaling.


title: Radio frequency association of heteronuclear Feshbach molecules

abstract:
  We present a detailed analysis of the production efficiency of weakly bound
heteronuclear KRb-Feshbach molecules using radio frequency association in a
harmonic trap. The efficiency was measured in a wide range of temperatures,
binding energies and radio frequencies. A comprehensive analytical model is
presented, explaining the observed asymmetric spectra and achieving good
quantitative agreement with the measured production rates. This model provides
a deep understanding of the molecule association process and paves the way for
future experiments which rely on Feshbach molecules e.g. for the production of
deeply bound molecules.


title:
Orbital and superorbital variability and their coupling in X-ray
  binaries

abstract:
  We review X-ray flux modulation from X-ray binaries on time scales
corresponding to the orbital period and those at longer time scales (so called
superorbital). Those modulations provide a powerful tool to constrain geometry
of the accretion flow. The most common cause of the superorbital variability
appears to be precession. We then discuss two specific examples of discoveries
of a coupling between the two types of variability and their physical
interpretation. One is Cyg X-1, a black-hole binary with a high-mass companion,
in which case we find the presence of an accretion bulge formed by collision of
the stellar wind with the outer edge of the precessing accretion disc. The
other is 4U 1820-303, a neutron star accreting from a low-mass white dwarf, in
which case we interpret the superorbital variability as accretion rate
modulation induced by interactions in a triple stellar system. Then, the
varying accretion rate leads to changes of the size of the accretion bulge in
that system, obscuring the centrally-emitted X-rays.


title:
Search for the Wh Production Using High-pT Isolated Like-Sign Dilepton
  Events in Run-II with 1.9 /fb

abstract:
  We search for the neutral higgs production associated with the $W$ boson
using high-$p_{T}$ isolated like-sign dilepton events in $p\bar{p}$ collisions
at $\sqrt{s}$ = 1.96 TeV. The data were collected with the CDF-II detector at
the Fermilab Tevatron collider and correspond to an integrated luminosity of
1.9 ${\rm fb}^{-1}$. We examine the dilepton events on the plane of the 2nd
lepton $p_{T}$ ($p_{T2}$) versus the $ p_{T}$ of dilepton system ($p_{T12}$)
and tune the final cut to maximize the sensitivity on the plane. We set the
final cut to the 2nd lepton $p_{T}$ greater than 20 GeV/c and the $p_{T}$ of
dilepton system greater than 15 GeV/c. The expected number of signal events is
0.46 for the fermiophobic higgs of the mass 110 GeV/$c^{2}$ and 0.19 for the
mass 160 GeV/$c^{2}$ assuming the Standard Model cross section. The number of
events for the Standard Model higgs is 0.02 and 0.18 for 110 GeV/$c^2$ and 160
GeV/$c^{2}$, respectively. The expected number of backgrounds is 3.23 $\pm$
0.69, while we observed 3 events in the data. From these results, we obtain the
limits on $\sigma(p\bar{p}\to Wh) \times Br(h\to W^{+}W^{-})$ of 2.2 pb for the
higgs of 110 GeV/$c^{2}$ and 1.4 pb for 160 GeV/$c^2$ at the 95% confidence
level.


title:
Dimensional characteristics of invariant measures for circle
  diffeomorphisms

abstract:
  We consider pointwise, box, and Hausdorff dimensions of invariant measures
for circle diffeomorphisms. We discuss the cases of rational, Diophantine, and
Liouville rotation numbers. Our main result is that for any Liouville number
$\tau$ there exists a $C^\infty$ circle diffeomorphism with rotation number
$\tau$ such that the pointwise and box dimensions of its unique invariant
measure do not exist. Moreover, the lower pointwise and lower box dimensions
can equal any value $0\le \beta \le 1$.


title: On the deformation theory of pair (X, E)

abstract:
  Huybrechts and Thomas recently constructed relative obstruction theory of
objects of the derived category of coherent sheaves over smooth projective
family. In this paper, we use this construction to obtain the absolute
deformation-obstruction theory of the pair (X, E), with X smooth projective
scheme and E perfect complex, and show that the obstruction theories for E,
(X,E), and X fit into exact triangle as derived objects on the moduli space.


title: Quantitative Riemann existence theorem over a number field

abstract:
  Given a covering of the projective line with ramifications defined over a
number field, we define a plain model of the algebraic curve realizing the
Riemann existence theorem for this covering, and bound explicitly the defining
equation of this curve and its definition field.


title: Minimum-volume hyperbolic 3-manifolds

abstract:
  We enumerate the small-volume manifolds that can be obtained by Dehn filling
on Mom-2 and Mom-3 manifolds as defined by Gabai, Meyerhoff, and the author. In
so doing we complete the proof that the Weeks manifold is the minimum-volume
compact hyperbolic 3-manifold, as well as enumerating the 10 smallest
one-cusped hyperbolic 3-manifolds.


title:
Search for SM Higgs Boson Produced in Association with a Z or a W Boson
  in events with $\etmiss$ and $b$-jets

abstract:
  We present a search for the Standard Model Higgs boson produced in
association with a Z or a W boson, using data collected with the CDF II
detector at the Tevatron accelerator. A scenario where the Z decays into
neutrinos or charged leptons originating from the W-decay escape detection and
the Higgs decays into a $b\overline{b}$ pair is considered. Therefore the
expected signature is large missing transverse energy ($\etmiss$), no isolated
leptons, and two $b$-jets. We present the preliminary results in this search
using 1.7$fb^{-1}$ of data collected by CDF and the work on future improvements
to increase the sensitivity of the analysis.


title:
Topological dynamics and dynamical scaling behavior of vortices in a
  two-dimensional XY model

abstract:
  By using topological current theory we study the inner topological structure
of vortices a two-dimensional (2D) XY model and find the topological current
relating to the order parameter field. A scalar field, $\psi$, is introduced
through the topological current theory. By solving the scalar field, the
interaction energy of vortices in a 2D XY model is revisited. We study the
dynamical evolution of vortices and present the branch conditions for
generating, annihilating, crossing, splitting and merging of vortices. During
the growth or annihilation of vortices, the dynamical scaling law of relevant
length in a 2D XY model, $\xi(t)\propto(t-t^*)^{1/z}$, is obtained in the
neighborhood of the limit point, given the dynamic exponent $z=2$. This
dynamical scaling behavior is consistent with renormalization group theory,
numerical simulations, and experimental results. Furthermore, it is found that
during the crossing, splitting and merging of vortices, the dynamical scaling
law of relevant length is $\xi(t)\propto(t-t^*)$. However, if vortices are at
rest during splitting or merging, the dynamical scaling law of relevant length
is a constat.


title: Central Forests in Trees

abstract:
  A new 2-parameter family of central structures in trees, called central
forests, is introduced. Minieka's $m$-center problem and McMorris's and Reid's
central-$k$-tree can be seen as special cases of central forests in trees. A
central forest is defined as a forest $F$ of $m$ subtrees of a tree $T$, where
each subtree has $k$ nodes, which minimizes the maximum distance between nodes
not in $F$ and those in $F$. An $O(n(m+k))$ algorithm to construct such a
central forest in trees is presented, where $n$ is the number of nodes in the
tree. The algorithm either returns with a central forest, or with the largest
$k$ for which a central forest of $m$ subtrees is possible. Some of the
elementary properties of central forests are also studied.


title: Stability of superfluid Fermi gases in optical lattices

abstract:
  Critical velocities of superfluid Fermi gases in optical lattices are
theoretically investigated across the BCS-BEC crossover. We calculate the
excitation spectra in the presence of a superfluid flow in one- and
two-dimensional optical lattices. It is found that the spectrum of low-lying
Anderson-Bogoliubov (AB) mode exhibits a roton-like structure in the
short-wavelength region due to the strong charge density wave fluctuations, and
with increasing the superfluid velocity one of the roton-like minima reaches
zero before the single-particle spectrum does. This means that superfluid Fermi
gases in optical lattices are destabilized due to spontaneous emission of the
roton-like AB mode instead of due to Cooper pair breaking.


title: Taxonomy of Clifford Cl_{3,0} subgroups: Choir and band groups

abstract:
  We list the subgroups of the basis set of Cl_{3,0} and classify them
according to three criteria for construction of universal Clifford algebras:
(1) each generator squares to +1 or -1, (2) the generators within the group
anticommute, and (3) the order of the resulting group is 2^{n+1}, where n is
the number of nontrivial generators. Obedient groups we call choirs;
disobedient groups, bands. We classify choirs by modes and bands by rhythms,
based on canonical equality. Each band generator has a transposition (number of
other generators it commutes with). The band's transposition signature is the
band's chord. The sum of transpositions divided by twice the number of
generator pair combinations is the band's beat. The band's order deviation is
the band's disorder. For n less than or equal 3, we show that the Cl_{3,0}
basis set has 21 non-isomorphic subgroups consisting of 9 choirs and 12 bands.


title: Instruction sequences and non-uniform complexity theory

abstract:
  We develop theory concerning non-uniform complexity in a setting in which the
notion of single-pass instruction sequence considered in program algebra is the
central notion. We define counterparts of the complexity classes P/poly and
NP/poly and formulate a counterpart of the complexity theoretic conjecture that
NP is not included in P/poly. In addition, we define a notion of completeness
for the counterpart of NP/poly using a non-uniform reducibility relation and
formulate complexity hypotheses which concern restrictions on the instruction
sequences used for computation. We think that the theory developed opens up an
additional way of investigating issues concerning non-uniform complexity.


title: Zero-temperature Glauber dynamics on Z^d

abstract:
  We study zero-temperature Glauber dynamics on \Z^d, which is a dynamic
version of the Ising model of ferromagnetism. Spins are initially chosen
according to a Bernoulli distribution with density p, and then the states are
continuously (and randomly) updated according to the majority rule. This
corresponds to the sudden quenching of a ferromagnetic system at high
temperature with an external field, to one at zero temperature with no external
field. Define p_c(\Z^d) to be the infimum over p such that the system fixates
at '+' with probability 1. It is a folklore conjecture that p_c(\Z^d) = 1/2 for
every 2 \le d \in \N. We prove that p_c(\Z^d) \to 1/2 as d \to \infty.


title:
Numerical simulations of buoyancy instabilities in galaxy cluster
  plasmas with cosmic rays and anisotropic thermal conduction

abstract:
  In clusters of galaxies, the specific entropy of intracluster plasma
increases outwards. Nevertheless, a number of recent studies have shown that
the intracluster medium is subject to buoyancy instabilities due to the effects
of cosmic rays and anisotropic thermal conduction. In this paper, we present a
new numerical algorithm for simulating such instabilities. This numerical
method treats the cosmic rays as a fluid, accounts for the diffusion of heat
and cosmic rays along magnetic field lines, and enforces the condition that the
temperature and cosmic-ray pressure remain positive. We carry out several tests
to ensure the accuracy of the code, including the detailed matching of analytic
results for the eigenfunctions and growth rates of linear buoyancy
instabilities. This numerical scheme will be useful for simulating convection
driven by cosmic-ray buoyancy in galaxy cluster plasmas and may also be useful
for other applications, including fusion plasmas, the interstellar medium, and
supernovae remnants.


title:
Simulations between triangular and hexagonal number-conserving cellular
  automata

abstract:
  A number-conserving cellular automaton is a cellular automaton whose states
are integers and whose transition function keeps the sum of all cells constant
throughout its evolution. It can be seen as a kind of modelization of the
physical conservation laws of mass or energy. In this paper, we first propose a
necessary condition for triangular and hexagonal cellular automata to be
number-conserving. The local transition function is expressed by the sum of
arity two functions which can be regarded as 'flows' of numbers. The
sufficiency is obtained through general results on number-conserving cellular
automata. Then, using the previous flow functions, we can construct effective
number-conserving simulations between hexagonal cellular automata and
triangular cellular automata.


title: Heisenberg chains cannot mirror a state

abstract:
  Faithful exchange of quantum information can in future become a key part of
many computational algorithms. Some Authors suggest to use chains of mutually
coupled spins as channels for quantum communication. One can divide these
proposals into the groups of assisted protocols, which require some additional
action from the users, and natural ones, based on the concept of state
mirroring. We show that mirror is fundamentally not the feature chains of
spins-1/2 coupled by the Heisenberg interaction, but without local magnetic
fields. This fact has certain consequences in terms of the natural state
transfer.


title: Truncated Moments of Structure Functions

abstract:
  We present a novel new approach to study quark-hadron duality using truncated
moments of structure functions, and determine the degree to which individual
resonance regions are dominated by leading twist.


title:
Low Dimensional Description of Pedestrian-Induced Oscillation of the
  Millennium Bridge

abstract:
  When it opened to pedestrian traffic in the year 2000, London's Millennium
Bridge exhibited an unwanted, large, side-to-side oscillation which was
apparently due to a resonance between the stepping frequency of walkers and one
of the bridge modes. Models for this event, and similar events on other
bridges, have been proposed. The model most directly addressing the
synchronization mechanism of individual walkers and the resulting global
response of the bridge-pedestrian system is one developed by Eckhardt et al.
This model treats individual walkers with a phase oscillator description and is
inherently high dimensional with system dimensionality (N+2), where N is the
number of walkers. In the present work we use a method proposed by Ott and
Antonsen to reduce the model of Eckhardt et al. to a low dimensional dynamical
system, and we employ this reduced description to study the global dynamics of
the bridge/pedestrian interaction. More generally, this treatment serves as an
interesting example of the possibility of low dimensional macroscopic behavior
in large systems of coupled oscillators.


title:
Precessing planetary magnetospheres in SiO stars ? First detection of
  quasi-periodic polarization fluctuations in R Leo and V Cam

abstract:
  The origin of magnetism around AGB stars is uncertain. If these stars drive a
dynamo, it cannot be sufficient to generate a strong global field, otherwise
the observed X-ray luminosities would be higher. Other explanations for the
circular polarization of SiO masers in the atmospheres are needed. The
interaction of the AGB wind with previously ejected matter and with planets
bears complex magneto-hydrodynamic phenomena on a short time scale, such that
strong magnetic fields can be maintained locally. Here we provide observational
evidence for the corresponding magnetic fluctuations. We trace magnetic
activity with the circular polarization of the v=1, J=2-1 SiO masers, using a
correlation polarimeter. In V Cam and R Leo, we find evidence of
pseudo-periodic fluctuations of the circular polarization on a timescale of a
few hours, from which we infer magnetic fluctuations of ~1G. The phenomenon is
rare and restricted to a narrow range of velocities. It seems to be associated
with planetary wake flows suggested by VLBI maps. While scenarios involving
magnetic activity in the extended stellar atmosphere have problems to explain
all observed features, precessing Jovian magnetospheres predict all of them.
For the case of R Leo, we constrain the orbit of the planet (estimated period
5.2 years) and estimate a stellar mass of 0.7 solar masses.


title: The Complexity of Enriched Mu-Calculi

abstract:
  The fully enriched μ-calculus is the extension of the propositional
μ-calculus with inverse programs, graded modalities, and nominals. While
satisfiability in several expressive fragments of the fully enriched
μ-calculus is known to be decidable and ExpTime-complete, it has recently
been proved that the full calculus is undecidable. In this paper, we study the
fragments of the fully enriched μ-calculus that are obtained by dropping at
least one of the additional constructs. We show that, in all fragments obtained
in this way, satisfiability is decidable and ExpTime-complete. Thus, we
identify a family of decidable logics that are maximal (and incomparable) in
expressive power. Our results are obtained by introducing two new automata
models, showing that their emptiness problems are ExpTime-complete, and then
reducing satisfiability in the relevant logics to these problems. The automata
models we introduce are two-way graded alternating parity automata over
infinite trees (2GAPTs) and fully enriched automata (FEAs) over infinite
forests. The former are a common generalization of two incomparable automata
models from the literature. The latter extend alternating automata in a similar
way as the fully enriched μ-calculus extends the standard μ-calculus.


title:
Stable magnetic equilibria and their evolution in the upper main
  sequence, white dwarfs, and neutron stars

abstract:
  [abbreviated] Long-lived, large-scale magnetic field configurations exist in
upper main sequence, white dwarf, and neutron stars. Externally, these fields
have a strong dipolar component, while their internal structure and evolution
are uncertain, but highly relevant for several problems in stellar and
high-energy astrophysics. We discuss the main properties expected for the
stable magnetic configurations in these stars from physical arguments, and how
these properties may determine the modes of decay of these configurations.
Stable magneto-hydrostatic equilibria are likely to exist in stars whenever the
matter in their interior is stably stratified (not barotropic). These
equilibria are not force-free and not required to satisfy the Grad-Shafranov
equation, but they do involve both toroidal and poloidal field components. We
argue that the main mode of decay for these configurations are processes that
lift the constraints set by stable stratification, such as heat diffusion in
main-sequence envelopes and white dwarfs, and beta decays or particle diffusion
in neutron stars. In the former, heat diffusion is not fast enough to make
these equilibria evolve over the stellar lifetime. In neutron stars, a strong
enough field might decay by overcoming the compositional stratification through
beta decays (at the highest field strengths) or through ambipolar diffusion
(for somewhat weaker fields). These processes convert magnetic energy to
thermal energy, and they occur at significant rates only once the latter is
smaller than the former, and therefore they substantially delay the cooling of
the neutron star, while slowly decreasing its magnetic energy.


title: Image of another universe being observed through a wormhole throat

abstract:
  We consider a technique of calculating deflection of the light passing
through wormholes (from one universe to another). We find fundamental and
characteristic features of electromagnetic radiation passing through the
wormholes. Making use of this, we propose new methods of observing distinctive
differences between wormholes and other objects as well as methods of
determining characteristic parameters for different wormhole models.


title:
Estimation of Cosmological Parameters from HI Observations of
  Post-reionization Epoch

abstract:
  The emission from neutral hydrogen (HI) clouds in the post-reionization era
(z < 6), too faint to be individually detected, is present as a diffuse
background in all low frequency radio observations below 1420 MHz. The angular
and frequency fluctuations of this radiation (~ 1 mK) is an important future
probe of the large scale structures in the Universe. We show that such
observations are a very effective probe of the background cosmological model
and the perturbed Universe. In our study we focus on the possibility of
determining the redshift space distortion parameter, coordinate distance and
its derivative with redshift. Using reasonable estimates for the observational
uncertainties and configurations representative of the ongoing and upcoming
radio interferometers, we predict parameter estimation at a precision
comparable with supernova Ia observations and galaxy redshift surveys, across a
wide range in redshift that is only partially accessed by other probes. Future
HI observations of the post-reionization era present a new technique,
complementing several existing one, to probe the expansion history and to
elucidate the nature of the dark energy.


title: Commensurate Quantum Oscillations in Coupled Qubits

abstract:
  We study the coupled-qubit oscillation driven by an oscillating field. When
the period of the non-resonant mode is commensurate with that of the resonant
mode of the Rabi oscillation, we show that the controlled-NOT (CNOT) gate
operation can be demonstrated. For a weak coupling the CNOT gate operation is
achievable by the commensurate oscillations, while for a sufficiently strong
coupling it can be done for arbitrary parameter values. By finely tuning the
amplitude of oscillating field it is shown that the high fidelity of the CNOT
gate can be obtained for any fixed coupling strength and qubit energy gap in
experiments.


title:
Photoluminescence spectroscopy of trions in quantum dots: a theoretical
  description

abstract:
  We present a full configuration interaction study of the spontaneous
recombination of neutral and singly charged excitons (trions) in semiconductor
quantum dots, from weak to strong coupling regimes. We find that the
enhancement of the recombination rate of neutral excitons with increasing dot
size is suppressed for negative trions, and even reversed for positive trions.
Our findings agree with recent comprehensive photoluminescence experiments in
self-assembled quantum dots [P. Dalgarno et al. Phys. Rev. B {\bf 77}, 245311
(2008)] and confirm the major role played by correlations in the valence
band.The effect of the temperature on the photoluminescence spectrum and that
of the ratio between the electron and hole wavefunction lengthscales are also
described.


title: Viscous fingering in volatile thin films

abstract:
  A thin water film on a cleaved mica substrate undergoes a first order phase
transition between two values of film thickness. By inducing a finite
evaporation rate of the water, the interface between the two phases develops a
fingering instability similar to that observed in the Saffman-Taylor problem.
We draw the connection between the two problems, and construct solutions
describing the dynamics of evaporation in this system.


title: Wave packet dynamics in a monolayer graphene

abstract:
  The dynamics of charge particles described by Gaussian wave packet in
monolayer graphene is studied analytically and numerically. We demonstrate that
the shape of wave packet at arbitrary time depends on correlation between the
initial electron amplitudes $\psi_1(\vec r,0)$ and $\psi_2(\vec r,0)$ on the
sublattices $A$ and $B$ correspondingly (i.e. pseudospin polarization). For the
transverse pseudospin polarization the motion of the center of wave packet
occurs in the direction perpendicular to the average momentum $ {\vec
p_0}=\hbar \vec{k_0}$. Moreover, in this case the initial wave packet splits
into two parts moving with opposite velocities along $ {\vec p_0}$. If the
initial direction of pseudospin coincides with average momentum the splitting
is absent and the center of wave packet is displaced at $t>0$ along the same
direction. The results of our calculations show that all types of motion
experience {\it zitterbewegung}. Besides, depending on initial polarization the
velocity of the packet center may have the constant component $v_c=uf(a)$,
where $u\approx 10^8 cm/s$ is the Fermi velocity and $f(a)$ is a function of
the parameter $a=k_0d$ ($d$ is the initial width of wave packet). As a result,
the direction of the packet motion is determined not only by the orientation of
the average momentum, but mainly by the phase difference between the up- and
low- components of the wave functions. Similar peculiarities of the dynamics of
2D electron wave packet connected with initial spin polarization should take
place in the semiconductor quantum well under the influence of the Rashba
spin-orbit coupling.


title:
Suppression of the rate of growth of dynamic heterogeneities and its
  relation to the local structure in a supercooled polydisperse liquid

abstract:
  The relationship between the microscopic arrangement of molecules in a
supercooled liquid and its slow dynamics at low temperature near glass
transition is studied by Molecular Dynamics (MD) simulations. A Lennard-Jones
liquid with polydispersity in size and mass of constituent particles is chosen
as the model system. Our studies reveal that the local structure (that varies
with polydispersity) plays a crucial role both in the slowing down of dynamics
and in the growth of the dynamic heterogeneities, besides determining the glass
forming ability (GFA) of the system. Increasing polydispersity at fixed volume
fraction is found to suppress the rate of growth of dynamic correlations, as
detected by the growth in the peak of the non-linear density response function.
The growth in dynamical correlation is manifested in a stronger than usual
breakdown of Stokes-Einstein relation at lower polydispersity at low
temperatures and also leads to a decrease in the fragility of the system with
polydispersity. We show that the suppression of the rate of growth of the
dynamic heterogeneity can be attributed to the loss of structural correlations
(as measured by the structure factor and the local bond orientational order)
with polydispersity. While a critical polydispersity is required to avoid
crystallization, we find that further increase in polydispersity lowers the
glass forming ability (GFA).


title: Geometry and arithmetic of verbal dynamical systems on simple groups

abstract:
  We study dynamical systems arising from word maps on simple groups. We
develop a geometric method based on the classical trace map for investigating
periodic points of such systems. These results lead to a new approach to the
search of Engel-like sequences of words in two variables which characterize
finite solvable groups. They also give rise to some new phenomena and concepts
in the arithmetic of dynamical systems.


title: Mass hierarchy and flavour mixing from discrete symmetries

abstract:
  We consider a class of discrete flavour symmetries for leptons based on the
group S(3) and A(4) with an hybrid breaking pattern. The aim is to construct
models in which the same flavon fields producing the mixing pattern are also
responsible for the mass hierarchy.


title: Age determinations of the open star clusters King 14 and NGC 146

abstract:
  We based on 2MASS J and Ks photometry for the open star clusters King 14 and
NGC 146, and using color magnitude diagrams with isochrones fit we have found
an age of log(age) = 7.8 (63 $\pm$8 Myr) for King 14 and log(age) = 7.5 (32
$\pm$8 Myr) for NGC 146. Our age determination is bigger than given in Lynga
[5] (log(age) = 7.2 for King 14 and log(age) = 7.1 for NGC 146) and less than
Dias [6] (log(age) = 7.9 for King 14 and log(age) = 7.8 for NGC 146)


title: Self-detecting gate-tunable nanotube paddle resonators

abstract:
  We have fabricated suspended metal paddle resonators with carbon nanotubes
functioning as self-detecting torsional springs. We observe gate-tunable
resonances, that either tune to higher or to lower frequencies when increasing
the dc voltage on the back-gate. We attribute the former modes to flexural
vibrations of the paddle resonator, while the latter ones are identified as
torsional vibrations. Compared to top-down silicon fabricated paddle
resonators, nanotube springs have smaller torsional spring constants and
provide a larger frequency tunability.


title: Special scrolls whose base curve has general moduli

abstract:
  In this paper we study the Hilbert scheme of smooth, linearly normal, special
scrolls under suitable assumptions on degree, genus and speciality.


title:
Impurity Effects in Sign Reversing Fully-Gapped Superconductors:
  Analysis of FeAs Superconductors

abstract:
  To understand the impurity effect on Tc in FeAs superconductors, we analyze a
simple two-band BCS model with repulsive interband interaction. The realized
fully-gapped superconducting state with sign reversal, which is predicted by
spin fluctuation theories in this compound, is suppressed by impurities due to
the interband hopping of Cooper pairs, if the interband impurity scattering
$I'$ is equal to the intraband one $I$. When $|I'/I| < 1$, in highly contrast,
Tc is almost unchanged by strong impurity scattering since the interband
scattering is almost prohibited by the multiple scattering effect. Since
$|I'/I| \sim 0.5$ is expected, the robustness of superconductivity against
impurities in FeAs superconductors is naturally understood in term of the sign
reversing fully-gapped state.


title: Cosmological tachyon condensation

abstract:
  We consider the prospects for dark matter/energy unification in k-essence
type theories. General mappings are established between the k-essence scalar
field, the hydrodynamic and braneworld descriptions. We develop an extension of
the general relativistic dust model that incorporates the effects of both
pressure and the associated acoustic horizon. Applying this to a tachyon model,
we show that this inhomogeneous "variable Chaplygin gas" does evolve into a
mixed system containing cold dark matter like gravitational condensate in
significant quantities. Our methods can be applied to any dark energy model as
well as to mixtures of dark energy and traditional dark matter.


title:
Subleading-color contributions to gluon-gluon scattering in N=4 SYM
  theory and relations to N=8 supergravity

abstract:
  We study the subleading-color (nonplanar) contributions to the four-gluon
scattering amplitudes in N=4 supersymmetric SU(N) Yang-Mills theory. Using the
formalisms of Catani and of Sterman and Tejeda-Yeomans, we develop explicit
expressions for the infrared-divergent contributions of all the
subleading-color L-loop amplitudes up to three loops, and make some conjectures
for the IR behavior for arbitrary L. We also derive several intriguing
relations between the subleading-color one- and two-loop four-gluon amplitudes
and the four-graviton amplitudes of N=8 supergravity. The exact one- and
two-loop N=8 supergravity amplitudes can be expressed in terms of the one- and
two-loop N-independent N=4 SYM amplitudes respectively, but the natural
generalization to higher loops fails, despite having a simple interpretation in
terms of the 't Hooft picture. We also find that, at least through two loops,
the subleading-color amplitudes of N=4 SYM theory have uniform
transcendentality (as do the leading-color amplitudes). Moreover, the N=4 SYM
Catani operators, which express the IR-divergent contributions of loop
amplitudes in terms of lower-loop amplitudes, are also shown to have uniform
transcendentality, and to be the maximum transcendentality piece of the QCD
Catani operators.


title:
Role of Third-Order Structure Function in Studying
  Two-Dimensionalisation of Turbulence

abstract:
  We look at various correlation functions, which include those that involve
both the velocity and the vorticity fields, in two-dimensional (2D) isotropic
homogeneous unforced turbulence. We adopt the more intuitive approach due to
Kolmogorov (and subsequently, Landau in his text on fluid dynamics) and show
that how the 2D turbulence's results, obtainable using other methods, may be
established in a simpler way. Same method is used to calculate some third-order
structure functions for quasi-geostrophic (QG) turbulence for the forward
cascade of pseudo-potential enstrophy and the inverse energy cascade in
quasi-geostrophic turbulence. These results motivate us to study the two-point
third order structure function in the context of the two-dimensionalisation
effect. Consequent studies enable us to give a reason for the inverse energy
cascade in the two-dimensionalised rapidly rotating three dimensional (3D)
incompressible turbulence. For such a system, literature shows a possibility of
the exponent of wavenumber in the energy spectrum's relation to lie between -2
and -3. We argue the existence of a stricter range of -2 to -7/3 for the
exponent in the case of rapidly rotating turbulence which is in accordance with
the recent experiments. Also, a derivation for the two point third order
structure function has been provided helping one to argue that even with slow
rotation one gets, although dominated, a spectrum with the exponent -2.87,
thereby hinting at the initiation of the two-dimensionalisation effect with
rotation. Moreover, using the Gledzer-Ohkitani-Yamada (GOY) shell model,
modified for rotation, these signatures of two-dimensionalisation effect have
been verified.


title:
Natural Transfer of Viable Microbes in Space from Planets in the
  Extra-Solar Systems to a Planet in our Solar System and Vice-Versa

abstract:
  We investigate whether it is possible that viable microbes could have been
transported to Earth from the planets in extra-solar systems by means of
natural vehicles such as ejecta expelled by comet or asteroid impacts on such
planets. The probabilities of close encounters with other solar systems are
taken into account as well as the limitations of bacterial survival times
inside ejecta in space, caused by radiation and DNA decay. The conclusion is
that no potentially DNA/RNA life-carrying ejecta from another solar system in
the general Galactic star field landed on Earth before life already existed on
Earth, not even if microbial survival time in space is as long as tens of
millions of years. However, if the Sun formed initially as a part of a star
cluster, as is commonly assumed, we cannot rule out the possibility of transfer
of life from one of the sister systems to us. Likewise, there is a possibility
that some extra-solar planets carry life that originated in our solar system.
It will be of great interest to identify the members of the Sun's birth cluster
of stars and study them for evidence for planets and life on the planets. The
former step may be accomplished by the GAIA mission, the latter step by the SIM
and DARWIN missions. Therefore it may not be too long until we have
experimental knowledge on the question whether the natural transfer of life
from one solar system to another has actually taken place.


title: Multipliers of periodic orbits in spaces of rational maps

abstract:
  Given a polynomial or a rational map f we associate to it a space of maps. We
introduce local coordinates in this space, which are essentially the set of
critical values of the map. Then we consider an arbitrary periodic orbit of f
with multiplier \rho\not=1 as a function of the local coordinates, and
establish a simple connection between the dynamical plane of f and the function
\rho in the space associated to f. The proof is based on the theory of
quasiconformal deformations of rational maps. As a corollary, we show that
multipliers of non-repelling periodic orbits are also local coordinates in the
space.


title: D-brane worlds and the cosmological constant

abstract:
  The cosmological constant on a D-brane is analyzed. This D-brane is in the
background produced by the p-brane solutions. The energy-momentum tensor in
this model has been found and the form of the cosmological constant has been
derived. This energy-momentum tensor is interpreted as an energy-momentum
tensor for a perfect fluid on the D-brane. The energy density and the pressure
for this fluid have been derived. As it turned out the pressure is negative but
the speed of sound is real.


title: A proposal for M2-brane-anti-M2-brane action

abstract:
  We propose a manifestly SO(8) invariant BF type Lagrangian for describing the
dynamics of M2-brane-anti-M2-brane system in flat spacetime. When one of the
scalars which satisfies a free-scalar equation takes a large expectation value,
the M2-brane-anti-M2-brane action reduces to the tachyon DBI action of
D2-brane-anti-D2-brane system in flat spacetime.


title:
Error calculus and regularity of Poisson functionals : the lent particle
  method

abstract:
  We propose a new method to apply the Lipschitz functional calculus of local
Dirichlet forms to Poisson random measures.


title:
Statistical Global Modeling of Beta-Decay Halflives Systematics Using
  Multilayer Feedforward Neural Networks and Support Vector Machines

abstract:
  In this work, the beta-decay halflives problem is dealt as a nonlinear
optimization problem, which is resolved in the statistical framework of Machine
Learning (LM). Continuing past similar approaches, we have constructed
sophisticated Artificial Neural Networks (ANNs) and Support Vector Regression
Machines (SVMs) for each class with even-odd character in Z and N to global
model the systematics of nuclei that decay 100% by the beta-minus-mode in their
ground states. The arising large-scale lifetime calculations generated by both
types of machines are discussed and compared with each other, with the
available experimental data, with previous results obtained with neural
networks, as well as with estimates coming from traditional global nuclear
models. Particular attention is paid on the estimates for exotic and halo
nuclei and we focus to those nuclides that are involved in the r-process
nucleosynthesis. It is found that statistical models based on LM can at least
match or even surpass the predictive performance of the best conventional
models of beta-decay systematics and can complement the latter.


title: Reflection groups acting on their hyperplanes

abstract:
  After having established elementary results on the relationship between a
finite complex (pseudo-)reflection group W < GL(V) and its reflection
arrangement A, we prove that the action of W on A is canonically related with
other natural representations of W, through a `periodic' family of
representations of its braid group. We also prove that, when W is irreducible,
then the squares of defining linear forms for A span the quadratic forms on V,
which imply |A| >= n(n+1)/2 for n = dim V, and relate the W-equivariance of the
corresponding map with the period of our family.


title: Temporal self-restoration of compressed optical filaments

abstract:
  We numerically investigate the propagation of a self-compressed optical
filament through a gas-glass-gas interface. Few-cycle light pulses survive a
sudden and short order-of-magnitude increase of nonlinearity and dispersion,
even when all conservative estimates predict temporal spreading or spatial
breakup. Spatio-temporal distortions are shown to self-heal upon further
propagation when the pulse refocuses in the second gas. This self-healing
mechanism has important implications for pulse compression techniques handled
by filamentation and explains the robustness of such sources.


title: Multiplicative Diophantine Exponents of Hyperplanes

abstract:
  We study multiplicative Diophantine approximation property of vectors and
compute Diophantine exponents of hyperplanes via dynamics.


title: A flexible Bayesian method for adaptive measurement in psychophysics

abstract:
  In psychophysical experiments time and the limited goodwill of participants
is usually a major constraint. This has been the main motivation behind the
early development of adaptive methods for the measurements of psychometric
thresholds. More recently methods have been developed to measure whole
psychometric functions in an adaptive way. Here we describe a Bayesian method
to measure adaptively any aspect of a psychophysical function, taking
inspiration from Kontsevich and Tyler's optimal Bayesian measurement method.
Our method is implemented in a complete and easy-to-use MATLAB package.


title:
On the origin of the anomalous behaviour of 2+ excitation energies in
  the neutron-rich Cd isotopes

abstract:
  Recent experimental results obtained using $\beta$ decay and isomer
spectroscopy indicate an unusual behaviour of the energies of the first excited
2$^{+}$ states in neutron-rich Cd isotopes approaching the N=82 shell closure.
To explain the unexpected trend, changes of the nuclear structure far-off
stability have been suggested, namely a quenching of the N=82 shell gap already
in $^{130}$Cd, only two proton holes away from doubly magic $^{132}$Sn. We
study the behaviour of the 2$^+$ energies in the Cd isotopes from N=50 to N=82,
i.e. across the entire span of a major neutron shell using modern beyond mean
field techniques and the Gogny force. We demonstrate that the observed low
2$^+$ excitation energy in $^{128}$Cd close to the N=82 shell closure is a
consequence of the doubly magic character of this nucleus for oblate
deformation favoring thereby prolate configurations rather than spherical ones.


title:
Domain walls, fusion rules and conformal field theory in the quantum
  Hall regime

abstract:
  We provide a simple way to obtain the fusion rules associated with elementary
quasi-holes over quantum Hall wave functions, in terms of domain walls. The
knowledge of the fusion rules is helpful in the identification of the
underlying conformal field theory describing the wave functions. We obtain the
fusion rules, and explicitly give a conformal field theory description, for a
two-parameter family (k,r) of wave functions. These include the Laughlin,
Moore-Read and Read-Rezayi states when r=2. The `gaffnian' wave function is the
prototypical example for r>2, in which case the conformal field theory is
non-unitary.


title: Weighing black holes from zero to high redshift

abstract:
  The application of the virial theorem provides a tool to estimate
supermassive black hole (BH) masses in large samples of active galactic nuclei
(AGN) with broad emission lines at all redshifts and luminosities, if the broad
line region (BLR) is gravitationally bound. In this paper we discuss the
importance of radiation forces on BLR clouds arising from the deposition of
momentum by ionizing photons. Such radiation forces counteract gravitational
ones and, if not taken into account, BH masses can be severely underestimated.
We provide virial relations corrected for the effect of radiation pressure and
we discuss their physical meaning and application. If these corrections to
virial masses, calibrated with low luminosity objects, are extrapolated to high
luminosities then the BLRs of most quasars might be gravitationally unbound.
The importance of radiation forces in high luminosity objects must be
thoroughly investigated to assess the reliability of quasar BH masses.


title: Survival benefits in mimicry: a quantitative framework

abstract:
  Mimicry is a resemblance between species that benefits at least one of the
species. It is a ubiquitous evolutionary phenomenon particularly common among
prey species, in which case the advantage involves better protection from
predation. We formulate a mathematical description of mimicry among prey
species, to investigate benefits and disadvantages of mimicry. The basic setup
involves differential equations for quantities representing predator behavior,
namely, the probabilities for attacking prey at the next encounter. Using this
framework, we present new quantitative results, and also provide a unified
description of a significant fraction of the quantitative mimicry literature.
The new results include `temporary' mutualism between prey species, and an
optimal density at which the survival benefit is greatest for the mimic. The
formalism leads naturally to extensions in several directions, such as the
evolution of mimicry, the interplay of mimicry with population dynamics, etc.
We demonstrate this extensibility by presenting some explorations on
spatiotemporal pattern dynamics.


title: VLA observations of the "water fountain" IRAS 16552-3050

abstract:
  We present Very Large Array (VLA) observations of the water maser emission
towards IRAS 16552-3050. The maser emission shows a velocity spread of ~170
km/s, and a bipolar distribution with a separation between the red and
blueshifted groups of ~0.08". These observations and the likely post-AGB nature
of the source indicate that IRAS 16552-3050 can be considered as a member of
the "water fountain" class of sources (evolved stars showing H2O maser emission
with a velocity spread $\ga$ 100 km/s, probably tracing collimated jets). The
water maser emission in IRAS 16552-3050 does not seem to be associated with
with any known optical counterpart. Moreover, this source does not have a
near-IR 2MASS counterpart, as it happens in about half of the water fountains
known. This suggests that these sources tend to be heavily obscured objects,
probably with massive precursors ($\ga 4-5$ M$_\odot$). We suggest that the
water maser emission in IRAS 16552-3050 could be tracing a rapidly precessing
bipolar jet.


title:
Uniform convergence for convexification of dominated pointwise
  convergent continuous functions

abstract:
  The Lebesgue dominated convergence theorem of the measure theory implies that
the Riemann integral of a bounded sequence of continuous functions over the
interval [ 0,1] pointwise converging to zero, also converges to zero. The
validity of this result is independent of measure theory, on the other hand,
this result together with only elementary functional analysis, can generate
measure theory itself. The mentioned result was also known before the
appearance of measure theory, but the original proof was very complicated. For
this reason this result, when presented in teaching, is generally obtained
based on measure theory. Later, Eberlein gave an elementary, but still
relatively complicated proof, and there were other simpler proofs but burdened
with complicated concepts, like measure theory. In this paper we give a short
and elementary proof even for the following strenghened form of the mentioned
result: a bounded sequence of continuous functions defined on a compact
topological space K pointwise converging to zero, has a suitable
convexification converging also uniformly to zero on $K,$ thus, e.g., the
original sequence converges weakly to zero in C(K). This fact can also be used
in the proof of the Krein-Smulian theorem. The usual proof beyond the simple
tools of the functional analysis, uses heavy embedding theorems and the Riesz'
representation theorem with the whole apparatus of measure theory. Our main
result, however, reduces the cited proof to a form in which we need abstract
tools only, namely the Hahn-Banach separation theorem and Alaoglu's theorem,
without Riesz' representation or any statement of measure theory.


title: Dyonic Non-Abelian Vortices

abstract:
  We study three-dimensional Yang-Mills-Higgs theories with and without a
Chern-Simons interaction. We find that these theories admit a rich spectrum of
vortex solitons carrying both a topological charge and a global flavour charge.
We further derive a low-energy description of the vortex dynamics from a gauged
linear sigma model on the vortex worldline.


title:
Parametrically-stimulated recovery of a microwave signal using standing
  spin-wave modes of a magnetic film

abstract:
  The phenomenon of storage and parametrically-stimulated recovery of a
microwave signal in a ferrite film has been studied both experimentally and
theoretically. The microwave signal is stored in the form of standing spin-wave
modes existing in the film due to its finite thickness. Signal recovery is
performed by means of frequency-selective amplification of one of these
standing modes by double- requency parametric pumping process. The time of
recovery, as well as the duration and magnitude of the recovered signal, depend
on the timing and amplitudes of both the input and pumping pulses. A mean-field
theory of the recovery process based on the competitive interaction of the
signal-induced standing spin-wave mode and thermal magnons with the parametric
pumping field is developed and compared to the experimental data.


title: The formation of planetary disks and winds: an ultraviolet view

abstract:
  Planetary systems are angular momentum reservoirs generated during star
formation. This accretion process produces very powerful engines able to drive
the optical jets and the molecular outflows. A fraction of the engine energy is
released into heating thus the temperature of the engine ranges from the 3000K
of the inner disk material to the 10MK in the areas where magnetic reconnection
occurs. There are important unsolved problems concerning the nature of the
engine, its evolution and the impact of the engine in the chemical evolution of
the inner disk. Of special relevance is the understanding of the shear layer
between the stellar photosphere and the disk; this layer controls a significant
fraction of the magnetic field building up and the subsequent dissipative
processes ougth to be studied in the UV.
  This contribution focus on describing the connections between 1 Myr old suns
and the Sun and the requirements for new UV instrumentation to address their
evolution during this period. Two types of observations are shown to be needed:
monitoring programmes and high resolution imaging down to, at least,
milliarsecond scales.


title:
Hamiltonian Structures and Reciprocal Transformations for the $r$-KdV-CH
  Hierarchy

abstract:
  The $r$-KdV-CH hierarchy is a generalization of the Korteweg-de Vries and
Camassa-Holm hierarchies parametrized by $r+1$ constants. In this paper we
clarify some properties of its multi-Hamiltonian structures, prove the
semisimplicity of the associated bihamiltonian structures and the formula for
their central invariants. By introducing a class of generalized Hamiltonian
structures, we give in a natural way the transformation formulae of the
Hamiltonian structures of the hierarchy under certain reciprocal
transformation, and prove the formulae at the level of its dispersionless
limit. We also consider relations of the associated bihamiltonian structures to
Frobenius manifolds.


title:
Dynamical Correlations of the Spin-1/2 Heisenberg XXZ Chain in a
  Staggered Field

abstract:
  We consider the easy-plane anisotropic spin-1/2 Heisenberg chain in combined
uniform longitudinal and transverse staggered magnetic fields. The low-energy
limit of his model is described by the sine-Gordon quantum field theory. Using
methods of integrable quantum field theory we determine the various components
of the dynamical structure factor. To do so, we derive explicit expressions for
all matrix elements of the low-energy projections of the spin operators
involving at most two particles. We discuss applications of our results to
experiments on one-dimensional quantum magnets.


title: A vapor cell based on dispensers for laser spectroscopy

abstract:
  We describe a simple strontium vapor cell for laser spectroscopy experiments.
Strontium vapor is produced using an electrically heated commercial dispenser
source. The sealed cell operates at room temperature, and without a buffer gas
or vacuum pump. The cell was characterised using laser spectroscopy, and was
found to offer stable and robust operation, with an estimated lifetime of
>10,000 hours. By changing the dispenser, this technique can be readily
extended to other alkali and alkaline earth elements.


title: Canonical Coin Systems for Change-Making Problems

abstract:
  The Change-Making Problem is to represent a given value with the fewest coins
under a given coin system. As a variation of the knapsack problem, it is known
to be NP-hard. Nevertheless, in most real money systems, the greedy algorithm
yields optimal solutions. In this paper, we study what type of coin systems
that guarantee the optimality of the greedy algorithm. We provide new proofs
for a sufficient and necessary condition for the so-called \emph{canonical}
coin systems with four or five types of coins, and a sufficient condition for
non-canonical coin systems, respectively. Moreover, we present an $O(m^2)$
algorithm that decides whether a tight coin system is canonical.


title:
The Lee-Yang and P\'olya-Schur Programs. I. Linear Operators Preserving
  Stability

abstract:
  In 1952 Lee and Yang proposed the program of analyzing phase transitions in
terms of zeros of partition functions. Linear operators preserving
non-vanishing properties are essential in this program and various contexts in
complex analysis, probability theory, combinatorics, and matrix theory. We
characterize all linear operators on finite or infinite-dimensional spaces of
multivariate polynomials preserving the property of being non-vanishing
whenever the variables are in prescribed open circular domains. In particular,
this solves the higher dimensional counterpart of a long-standing
classification problem originating from classical works of Hermite, Laguerre,
Hurwitz and P\'olya-Schur on univariate polynomials with such properties.

categories: math.CV cond-mat.stat-mech math-ph math.CO math.MP


title: Supersingular representations of GL_2(Q_p) and (phi,Gamma)-modules

abstract:
  The purpose of this note is to give a direct proof of the fact that if one
applies Colmez' functor to a two dimensional irreducible F_p^bar-representation
of Gal(Q_p^bar/Q_p), one gets the restriction to the Borel subgroup of
GL_2(Q_p) of a supersingular representation.


title:
The death of massive stars - I. Observational constraints on the
  progenitors of type II-P supernovae

abstract:
  We present the results of a 10.5 yr, volume limited (28 Mpc) search for
supernova (SN) progenitor stars. We compile all SNe discovered within this
volume (132, of which 27% are type Ia) and determine the relative rates of each
sub-type from literature studies : II-P (59%), Ib/c (29%), IIb (5%), IIn (4%)
and II-L (3%). Twenty II-P SNe have high quality optical or near-IR
pre-explosion images that allow a meaningful search for the progenitor stars.
In five cases they are clearly red supergiants, one case is unconstrained, two
fall on compact coeval star clusters and the other twelve have no progenitor
detected. We review and update all the available data for the host galaxies
(distance, metallicity and extinction) and determine masses and upper mass
estimates using the STARS stellar evolutionary code and a single consistent
homogeneous method. A maximum likelihood calculation suggests that the minimum
stellar mass for a type II-P to form is m(min)=8.5 +1/-1.5 Msol and the maximum
mass for II-P progenitors is m(max)=16.5 +/- 1.5 Msol, assuming a Salpeter
initial mass function (in the range Gamma = -1.35 +0.3/-0.7). The minimum mass
is consistent with current estimates for white dwarf progenitor masses, but the
maximum mass does not appear consistent with massive star populations. Red
supergiants in the Local Group have masses up to 25Msol and the minimum mass to
produce a Wolf-Rayet star in single star evolution (between solar and LMC
metallicity) is similarly 25-30 Msol. We term this discrepancy the "red
supergiant problem" and speculate that these stars could have core masses high
enough to form black holes and SNe which are too faint to have been detected.
Low luminosity SNe with low 56Ni production seem to arise from explosions of
low mass progenitors near the mass threshold for core-collapse. (abridged).


title:
Spin dependent Fermi Liquid parameters and properties of polarized quark
  matter

abstract:
  We calculate the spin dependent Fermi liquid parameters (FLPs), single
particle energies and energy densities of various spin states of polarized
quark matter. The expressions for the incompressibility($K$) and sound velocity
($c_1$) in terms of the spin dependent FLPs and polarization parameter $(\xi)$
are derived. Estimated values of $K$ and $c_1$ reveal that the equation of
state (EOS) of the polarized matter is stiffer than the unpolarized one.
Finally we investigate the possibility of the spin polarization
(ferromagnetism) phase transition.


title: CME liftoff with high-frequency fragmented type II burst emission

abstract:
  Aims: Solar radio type II bursts are rarely seen at frequencies higher than a
few hundred MHz. Since metric type II bursts are thought to be signatures of
propagating shock waves, it is of interest to know how these shocks, and the
type II bursts, are formed. In particular, how are high-frequency, fragmented
type II bursts created? Are there differences in shock acceleration or in the
surrounding medium that could explain the differences to the "typical" metric
type IIs? Methods: We analyse one unusual metric type II event in detail, with
comparison to white-light, EUV, and X-ray observations. As the radio event was
associated with a flare and a coronal mass ejection (CME), we investigate their
connection. We then utilize numerical MHD simulations to study the shock
structure induced by an erupting CME in a model corona including dense loops.
Results: Our simulations show that the fragmented part of the type II burst can
be formed when a coronal shock driven by a mass ejection passes through a
system of dense loops overlying the active region.To produce fragmented
emission, the conditions for plasma emission have to be more favourable inside
the loop than in the interloop area. The obvious hypothesis, consistent with
our simulation model, is that the shock strength decreases significantly in the
space between the denser loops. The later, more typical type II burst appears
when the shock exits the dense loop system and finally, outside the active
region, the type II burst dies out when the changing geometry no longer favours
the electron shock-acceleration.


title: Foundations of the Pareto Iterated Local Search Metaheuristic

abstract:
  The paper describes the proposition and application of a local search
metaheuristic for multi-objective optimization problems. It is based on two
main principles of heuristic search, intensification through variable
neighborhoods, and diversification through perturbations and successive
iterations in favorable regions of the search space. The concept is
successfully tested on permutation flow shop scheduling problems under multiple
objectives. While the obtained results are encouraging in terms of their
quality, another positive attribute of the approach is its' simplicity as it
does require the setting of only very few parameters. The implementation of the
Pareto Iterated Local Search metaheuristic is based on the MOOPPS computer
system of local search heuristics for multi-objective scheduling which has been
awarded the European Academic Software Award 2002 in Ronneby, Sweden
(http://www.easa-award.net/, http://www.bth.se/llab/easa_2002.nsf)


title: The Nearest OB Association: Scorpius-Centaurus (Sco OB2)

abstract:
  We summarize observational results on the stellar population and star
formation history of the Scorpius-Centaurus OB Association (Sco OB2), the
nearest region of recent massive star formation. It consists of three
subgroups, Upper Scorpius (US), Upper Centaurus-Lupus (UCL), and Lower
Centaurus-Crux (LCC) which have ages of about 5, 17, and 16 Myr. In Upper
Scorpius, numerous studies have recently revealed hundreds of low-mass
association members, including dozens of brown dwarfs. The empirical mass
function could be established over the full stellar mass range from 0.1 M_sun
up to 20 M_sun, and was found to be consistent with recent determinations of
the field initial mass function. A narrow range of ages around 5 Myr was found
for the low-mass stars, the same age as had previously (and independently) been
derived for the high-mass members. This supports earlier indications that the
star formation process in US was triggered, and agrees with previous
conjectures that the triggering event was a supernova- and wind-driven
shock-wave originating from the nearby UCL group. In the older UCL and LCC
regions, large numbers of low-mass members have recently been identified among
X-ray and proper-motion selected candidates. In both subgroups, low-mass
members have also been serendipitously discovered through investigations of
X-ray sources in the vicinity of better known regions (primarily the Lupus and
TW Hya associations). While both subgroups appear to have mean ages of ~16 Myr,
they both show signs of having substructure. Their star-formation histories may
be more complex than that of the younger, more compact US group. ... (abstract
abbreviated; see paper for full abstract).


title: The charge conjugation quantum number in multiquark systems

abstract:
  We discuss the charge conjugation quantum number for tetraquarks or
meson-meson molecules, seen as possible interpretations of the newly found
$XYZ$ charmonium-like resonances.


title: Optical Spectroscopy of the ULX-Associated Nebula MF16

abstract:
  We present the results of optical panoramic and long-slit spectroscopy of the
nebula MF16 associated with the Ultraluminous X-ray Source NGC6946 ULX-1. More
than 20 new emission lines are identified in the spectra. Using characteristic
line ratios we find the electron density n_e ~ 600cm^{-3}, electron temperature
in the range from ~9000K to ~20 000K (for different diagnostic lines) and the
total emitting gas mass M ~ 900 Msolar. We also estimate the interstellar
extinction towards the nebula as A_V = 1.m54 somewhat higher than the Galactic
absorption. Observed line luminosities and ratios appear to be inconsistent
with excitation and ionization by shock waves so we propose the central object
responsible for powering the nebula. We estimate the parameters of the ionizing
source using photon number estimates and Cloudy modelling. Required EUV
luminosity ($\sim 10^{40}$\ergl) is high even if compared with the X-ray
luminosity. We argue that independently of their physical nature ULXs are
likely to be bright UV and EUV sources. It is shown that the UV flux expected
in the GALEX spectral range (1000-3000Angstroms) is quite reachable for UV
photometry. Measuring the luminosities and spectral slopes in the UV range may
help to distinguish between the two most popular ULX models.


title:
A Computational Study of Genetic Crossover Operators for Multi-Objective
  Vehicle Routing Problem with Soft Time Windows

abstract:
  The article describes an investigation of the effectiveness of genetic
algorithms for multi-objective combinatorial optimization (MOCO) by presenting
an application for the vehicle routing problem with soft time windows. The work
is motivated by the question, if and how the problem structure influences the
effectiveness of different configurations of the genetic algorithm.
Computational results are presented for different classes of vehicle routing
problems, varying in their coverage with time windows, time window size,
distribution and number of customers. The results are compared with a simple,
but effective local search approach for multi-objective combinatorial
optimization problems.


title:
Revised fits to $\Delta\alpha/\alpha$ in consistency with the
  accelerating universe

abstract:
  An attempt is made for a new type of analysis of the time-variability of the
fine-structure constant trying to fit the most recent result from the
laboratory measurements, the Oklo constraint and the data from the QSO
absorption lines all in consistency with the accelerating universe.


title: Pion Scattering in Wilson Chiral Perturbation Theory

abstract:
  We compute the scattering amplitude in Wilson Chiral Perturbation Theory for
two flavors. The lattice spacing effects due to the explicit chiral symmetry
breaking are kept through O(a^2), and we consider the regime where the quark
mass m is of order a^2 Lambda_^3. Analytic expressions for the scattering
lengths in different isospin channels are given. As a result of the O(a^2)
terms the scattering lengths do not vanish in the chiral limit. Moreover,
additional chiral logarithms proportional to a^2 ln M_pi^2 are present in the
one-loop results. These contributions can obscure the continuum chiral
logarithms and the determination of low-energy constants from numerical lattice
simulations.


title: Collective Motion due to escape and pursuit response

abstract:
  Recent studies suggest that non-cooperative behavior such as cannibalism may
also be a driving mechanism of collective motion. Motivated by these novel
results we introduce a simple model of Brownian particles interacting by
pursuit and escape interactions. We show the onset of collective motion due to
escape and pursuit response of individuals and demonstrate how experimentally
accessible macroscopic observables depend strongly on the ratio of the escape
and pursuit strength. We analyze the different impact of the escape and pursuit
response on the motion statistics and determine the scaling of the migration
speed with model parameters.