title:
Rational solutions of the discrete time Toda lattice and the alternate
  discrete Painleve II equation

abstract:
  The Yablonskii-Vorob'ev polynomials $y_{n}(t)$, which are defined by a second
order bilinear differential-difference equation, provide rational solutions of
the Toda lattice. They are also polynomial tau-functions for the rational
solutions of the second Painlev\'{e} equation ($P_{II}$). Here we define
two-variable polynomials $Y_{n}(t,h)$ on a lattice with spacing $h$, by
considering rational solutions of the discrete time Toda lattice as introduced
by Suris. These polynomials are shown to have many properties that are
analogous to those of the Yablonskii-Vorob'ev polynomials, to which they reduce
when $h=0$. They also provide rational solutions for a particular
discretisation of $P_{II}$, namely the so called {\it alternate discrete}
$P_{II}$, and this connection leads to an expression in terms of the Umemura
polynomials for the third Painlev\'{e} equation ($P_{III}$). It is shown that
B\"{a}cklund transformation for the alternate discrete Painlev\'{e} equation is
a symplectic map, and the shift in time is also symplectic. Finally we present
a Lax pair for the alternate discrete $P_{II}$, which recovers Jimbo and Miwa's
Lax pair for $P_{II}$ in the continuum limit $h\to 0$.


title:
An adaptive embedded architecture for real-time Particle Image
  Velocimetry algorithms

abstract:
  Particle Image Velocimetry (PIV) is a method of im-aging and analysing fields
of flows. The PIV tech-niques compute and display all the motion vectors of the
field in a resulting image. Speeds more than thou-sand vectors per second can
be required, each speed being environment-dependent. Essence of this work is to
propose an adaptive FPGA-based system for real-time PIV algorithms. The
proposed structure is ge-neric so that this unique structure can be re-used for
any PIV applications that uses the cross-correlation technique. The major
structure remains unchanged, adaptations only concern the number of processing
operations. The required speed (corresponding to the number of vector per
second) is obtained thanks to a parallel processing strategy. The image
processing designer duplicates the processing modules to distrib-ute the
operations. The result is a FPGA-based archi-tecture, which is easily adapted
to algorithm specifica-tions without any hardware requirement. The design flow
is fast and reliable.


title: Higgs hunting with B decays

abstract:
  B physics is sensitive to the effects of Higgs bosons in the Minimal
Supersymmetric Standard Model, if the parameter tan beta is large. I briefly
summarise the role of B -> mu+ mu- and B -> tau nu in the hunt for new Higgs
effects and present new results on the decay B -> D tau nu: Using the
analyticity properties of form factors one can predict the ratio R=Br(B -> D
tau nu)/Br(B -> D l nu), l=e,mu, with small hadronic uncertainties. In the
Standard Model one finds R= 0.31 +/- 0.02, Br(B^- -> D^0 tau^- anti-nu) = (0.71
+/- 0.09)% and Br(anti-B^0 -> D^+ tau^- anti-nu)= (0.66 +/- 0.08)%, if the
vector form factor of the Heavy Flavor Averaging Group is used. B -> D tau nu
is competitive with B -> tau nu in the search for effects of charged Higgs
bosons. Especially sensitive to the latter is the differential distribution in
the decay chain anti-B -> D anti-nu tau^-[->pi- nu].


title:
A path following algorithm for Sparse Pseudo-Likelihood Inverse
  Covariance Estimation (SPLICE)

abstract:
  Given n observations of a p-dimensional random vector, the covariance matrix
and its inverse (precision matrix) are needed in a wide range of applications.
Sample covariance (e.g. its eigenstructure) can misbehave when p is comparable
to the sample size n. Regularization is often used to mitigate the problem.
  In this paper, we proposed an l1-norm penalized pseudo-likelihood estimate
for the inverse covariance matrix. This estimate is sparse due to the l1-norm
penalty, and we term this method SPLICE. Its regularization path can be
computed via an algorithm based on the homotopy/LARS-Lasso algorithm.
Simulation studies are carried out for various inverse covariance structures
for p=15 and n=20, 1000. We compare SPLICE with the l1-norm penalized
likelihood estimate and a l1-norm penalized Cholesky decomposition based
method. SPLICE gives the best overall performance in terms of three metrics on
the precision matrix and ROC curve for model selection. Moreover, our
simulation results demonstrate that the SPLICE estimates are positive-definite
for most of the regularization path even though the restriction is not
enforced.


title:
Magnetism, superconductivity, and pairing symmetry in Fe-based
  superconductors

abstract:
  We analyze antiferromagnetism and superconductivity in novel $Fe-$based
superconductors within the itinerant model of small electron and hole pockets
near $(0,0)$ and $(\pi,\pi)$. We argue that the effective interactions in both
channels logarithmically flow towards the same values at low energies, {\it
i.e.}, antiferromagnetism and superconductivity must be treated on equal
footings. The magnetic instability comes first for equal sizes of the two
pockets, but looses to superconductivity upon doping. The superconducting gap
has no nodes, but changes sign between the two Fermi surfaces (extended s-wave
symmetry). We argue that the $T$ dependencies of the spin susceptibility and
NMR relaxation rate for such state are exponential only at very low $T$, and
can be well fitted by power-laws over a wide $T$ range below $T_c$.


title: Sneutrino NLSP Scenarios in the NUHM with Gravitino Dark Matter

abstract:
  We analyze scenarios in which some flavour of sneutrino is the
next-to-lightest supersymmetric particle (NLSP), assuming that the gravitino is
the lightest supersymmetric particle (LSP) and provides the cold dark matter.
Such scenarios do not arise in the constrained supersymmetric extension of the
Standard Model (CMSSM) with universal gaugino and scalar masses input at the
GUT scale. However, models with non-universal Higgs masses (NUHM) do allow
scenarios with a sneutrino NLSP, which are quite generic. We illustrate how
such scenarios may arise, analyze the possible metastable sneutrino lifetime,
and explore the theoretical, phenomenological, experimental and cosmological
constraints on such scenarios. We also discuss the collider signatures of such
scenarios, how they may be distinguished from neutralino LSP scenarios, and how
different flavours of sneutrino NLSP may be distinguished.


title: A key role for unusual spin dynamics in ferropnictides

abstract:
  The 2008 discovery of superconducting ferropnictides with Tc~26K-56K
introduced a new family of materials into the category of high Tc
superconductors. The ongoing project of understanding the superconducting
mechanism and pairing symmetry has already revealed a complicated and often
contradictory underlying picture of the structural and magnetic properties.
There is an almost unprecedented sensitivity of the calculated magnetism and
Fermi surface to structural details that prohibits correspondence with
experiment. Furthermore, experimental probes of the order parameter symmetry
are in surprisingly strong disagreement, even considering the relative
immaturity of the field. Here we outline all of the various and seemingly
contradictory evidences, both theoretical and experimental, and show that they
can be rectified if the system is assumed to be highly magnetic with a spin
density wave that is well-defined but with magnetic twin and anti-phase
boundaries that are dynamic on the time-scale of experiments. Under this
assumption, we find that our calculations can accurately reproduce even very
fine details of the structure, and a natural explanation for the temperature
separation of structural and magnetic transitions is provided. Thus, our theory
restores agreement between experiment and theory in crucial areas, making
further cooperative progress possible on both fronts. We believe that
fluctuating magnetic domains will be an essential component of unravelling the
interplay between magnetic interactions and superconductivity in these newest
high Tc superconductors.


title: Odd-graceful labelings of trees of diameter 5

abstract:
  A difference vertex labeling of a graph G is an assignment f of labels to the
vertices of G that induces for each edge xy the weight |f(x)-f(y)|. A
difference vertex labeling f of a graph G of size n is odd-graceful if f is an
injection from V(G) to {0,1,...,2n-1} such that the induced weights are
{1,3,...,2n-1}. We show here that any forest whose components are caterpillars
is odd-graceful. We also show that every tree of diameter up to five is
odd-graceful.


title:
Transiting exoplanets from the CoRoT space mission V. CoRoT-Exo-4b:
  Stellar and planetary parameters

abstract:
  The CoRoT satellite has announced its fourth transiting planet (Aigrain et
al. 2008) with space photometry. We describe and analyse complementary
observations of this system performed to establish the planetary nature of the
transiting body and to estimate the fundamental parameters of the planet and
its parent star. We have analysed high precision radial-velocity data,
ground-based photometry, and high signal-to-noise ratio spectroscopy. The
parent star CoRoT-Exo-4 (2MASS 06484671-0040219) is a late F-type star of mass
of 1.16 Msun and radius of 1.17 Rsun. The planet has a circular orbit with a
period of 9.20205d. The planet radius is 1.19 Rjup and the mass is 0.72 Mjup.
It is a gas-giant planet with a ''normal'' internal structure of mainly H and
He. CoRoT-Exo-4b has the second longest period of the known transiting planets.
It is an important discovery since it occupies an empty area in the mass-period
diagram of transiting exoplanets.


title: Baryogenesis via Leptogenesis in Adjoint SU(5)

abstract:
  The possibility to explain the baryon asymmetry in the Universe through the
leptogenesis mechanism in the context of Adjoint SU(5) is investigated. In this
model the neutrino masses are generated through the Type I and Type III seesaw
mechanisms, and the field responsible for the Type III seesaw, called rho_3,
generates the B-L asymmetry needed to satisfy the observed value of the baryon
asymmetry in the Universe. We find that the CP asymmetry originates only from
the vertex correction, since the self-energy contribution is not present. When
neutrino masses have a normal hierarchy, successful leptogenesis is possible
for 10^{11} GeV < M_{\rho_3}^{NH} < 4 10^{14} GeV. When the neutrino hierarchy
is inverted, the allowed mass range changes to 2 10^{11} GeV < M_{\rho_3}^{IH}
< 5 10^{11} GeV. These constraints make possible to rule out a large part of
the parameter space in the theory which was allowed by the unification of gauge
interactions and the constraints coming from proton decay.


title: Theory of Superconductivity in the Cuprates

abstract:
  The quantum critical fluctuations of the time-reversal breaking order
parameter which is observed in the pseudogap regime of the Cuprates are shown
to couple to the lattice equivalent of the local angular momentum of the
fermions. Such a coupling favors scattering of fermions through angles close to
$\pm \pi/2$ which is unambiguously shown to promote d-wave pairing. The right
order of magnitude of both $T_c$ and the normalized zero temperature gap
$\Delta/T_c$ are calculated using the same fluctuations which give the
temperature, frequency and momentum dependence of the the anomalous normal
state properties for dopings near the quantum-critical value and with two
parameters extracted from fit to such experiments.


title:
Towards an Accurate Determination of Parameters for Very Massive Stars:
  the Eclipsing Binary LMC-SC1-105

abstract:
  This paper presents a photometric and spectroscopic study of the bright blue
eclipsing binary LMC-SC1-105, selected from the OGLE catalog as a candidate
host of very massive stars (>=30Mo). The system is found to be a double-lined
spectroscopic binary, which indeed contains massive stars. The masses and radii
of the components are M1= 30.9+/-1.0 Mo, M2= 13.0+/-0.7 Mo, and R1= 15.1+/-0.2
Ro, R2= 11.9+/-0.2 Ro, respectively. The less massive star is found to be
filling its Roche lobe, indicating the system has undergone mass-transfer. The
spectra of LMC-SC1-105 display the Struve-Sahade effect, with the HeI lines of
the secondary appearing stronger when it is receding and causing the spectral
types to change with phase (O8+O8 to O7+O8.5). This effect could be related to
the mass-transfer in this system. To date, accurate (<=10%) fundamental
parameters have only been measured for 15 stars with masses greater than 30 Mo,
with the reported measurements contributing valuable data on the fundamental
parameters of very massive stars at low metallicity. The results of this work
demonstrate that the strategy of targeting the brightest blue stars in
eclipsing binaries is an effective way of studying very massive stars.


title: Symmetry Energy I: Semi-Infinite Matter

abstract:
  Energy for a nucleus is considered in macroscopic limit, in terms of nucleon
numbers. Further considered for a nuclear system is the Hohenberg-Kohn energy
functional, in terms of proton and neutron densities. Finally,
Skyrme-Hartree-Fock calculations are carried out for a half-infinite
particle-stable nuclear-matter. In each case, the attention is focused on the
role of neutron-proton asymmetry and on the nuclear symmetry energy. We extend
the considerations on the symmetry term from an energy formula to the
respective term in the Hohenberg-Kohn functional. We show, in particular, that
in the limit of an analytic functional, and subject to possible Coulomb
corrections, it is possible to construct isoscalar and isovector densities out
of the proton and neutron densities, that retain a universal relation to each
other, approximately independent of asymmetry. In the so-called local
approximation, the isovector density is inversely proportional to the symmetry
energy in uniform matter at the local isoscalar density. Generalized symmetry
coefficient of a nuclear system is related, in the analytic limit of a
functional, to an integral of the isovector density. We test the relations,
inferred from the Hohenberg-Kohn functional, in the Skyrme-Hartree-Fock
calculations of half-infinite matter. Within the calculations, we obtain
surface symmetry coefficients and parameters characterizing the densities, for
the majority of Skyrme parameterizations proposed in the literature. The
volume-to-surface symmetry-coefficient ratio and the displacement of nuclear
isovector relative to isoscalar surfaces both strongly increase as the slope of
symmetry energy in the vicinity of normal density increases.


title: Age Determination of Six Intermediate-age SMC Star Clusters with HST/ACS

abstract:
  We present a photometric analysis of the star clusters Lindsay 1, Kron 3,
NGC339, NGC416, Lindsay 38, and NGC419 in the Small Magellanic Cloud (SMC),
observed with the Hubble Space Telescope Advanced Camera for Surveys (ACS) in
the F555W and F814W filters. Our color magnitude diagrams (CMDs) extend ~3.5
mag deeper than the main-sequence turnoff points, deeper than any previous
data. Cluster ages were derived using three different isochrone models: Padova,
Teramo, and Dartmouth, which are all available in the ACS photometric system.
Fitting observed ridgelines for each cluster, we provide a homogeneous and
unique set of low-metallicity, single-age fiducial isochrones. The cluster CMDs
are best approximated by the Dartmouth isochrones for all clusters, except for
NGC419 where the Padova isochrones provided the best fit. The CMD of NGC419
shows several main-sequence turn-offs, which belong to the cluster and to the
SMC field. We thus derive an age range of 1.2-1.6 Gyr for NGC419.
Interestingly, our intermediate-age star clusters have a metallicity spread of
~0.6 dex, which demonstrates that the SMC does not have a smooth, monotonic
age-metallicity relation. We find an indication for centrally concentrated blue
straggler star candidates in NGC416, while for the other clusters these are not
present. Using the red clump magnitudes, we find that the closest cluster,
NGC419 (~50kpc), and the farthest cluster, Lindsay 38 (~67kpc), have a relative
distance of ~17kpc, which confirms the large depth of the SMC.


title:
Fine-tuning criteria for inflation and the search for primordial
  gravitational waves

abstract:
  We revisit arguments that simple models of inflation with a small red tilt in
the scalar power spectrum generically yield an observable tensor spectrum. We
show that criteria for fine-tuning based upon the algebraic simplicity of the
potential depend strongly upon the explicit assumptions they incorporate,
particularly regarding the end of inflation. In addition, some models with
algebraically simple potentials require carefully tuned initial field
configurations, and not all types of fine-tuning are identifiable via the
algebraic simplicity of the potential. Conversely, in the absence of a strong
prior on the mechanism that ends inflation, we demonstrate the existence of
potentials with vanishingly small tensor amplitudes which are natural in terms
of both their algebraic form and initial conditions. We thus argue that
proposed experiments (CMBPol or BBO) which make highly sensitive measurements
of the tensor amplitude cannot definitively rule out the inflationary paradigm.


title: T-Lyr1-17236: A Long-Period Low-Mass Eclipsing Binary

abstract:
  We describe the discovery of a 0.68+0.52 solar mass eclipsing binary (EB)
with an 8.4-day orbital period, found through a systematic search of ten fields
of the Trans-atlantic Exoplanet Survey (TrES). Such long-period low-mass EBs
constitute critical test cases for resolving the long standing discrepancy
between the theoretical and observational mass-radius relations at the bottom
of the main sequence. It has been suggested that this discrepancy may be
related to strong stellar magnetic fields, which are not properly accounted for
in current theoretical models. All previously well-characterized low-mass main
sequence EBs have periods of a few days or less, and their components are
therefore expected to be rotating rapidly as a result of tidal synchronization,
thus generating strong magnetic fields. In contrast, the binary system
described here has a period that is over three times longer than previously
characterized low-mass main sequence EBs, and its components rotate relatively
slowly. It is therefore expected to have a weaker magnetic field and to better
match the assumptions of theoretical stellar models. Our follow-up observations
of this EB yield preliminary stellar properties that suggest it is indeed
consistent with current models. If further observations confirm a low level of
activity in this system, these determinations would provide support for the
hypothesis that the mass-radius discrepancy is at least partly due to magnetic
activity.


title: The Stellar Populations of Stripped Spiral Galaxies in the Virgo Cluster

abstract:
  (Abridged) We present an analysis of the stellar populations of the
gas-stripped outer disks of ten Virgo Cluster spiral galaxies, utilizing
SparsePak integral field spectroscopy on the WIYN 3.5m telescope and GALEX UV
photometry. The galaxies in our sample show evidence for being gas-stripped
spiral galaxies, with star formation within a truncation radius, and a passive
population beyond the truncation radius. We find that all of the galaxies with
spatially truncated star formation have outer disk stellar populations
consistent with star formation ending within the last 500 Myr. The synthesis of
optical spectroscopy and GALEX observations demonstrate that star formation was
relatively constant until the quenching time, after which the galaxies
passively evolved. Large starbursts at the time of quenching are excluded for
all galaxies. For approximately half of our galaxies, timescales derived from
our observations are consistent with galaxies being stripped in or near the
cluster core, where simple ram-pressure estimates can explain the stripping.
However, the other half of our sample galaxies were clearly stripped outside
the cluster core. Such galaxies provide evidence that the intra-cluster medium
is not static and smooth. For three of our sample galaxies, our stripping
timescales agree with those from the gas stripping simulations, suggesting that
star formation is quenched near the time of peak pressure. While the stripping
of star-forming gas in the outer disk creates a passive population in our
galaxies, there is still normal star formation in the center of our sample
galaxies. It may be that Virgo is not massive enough to completely strip these
spiral galaxies and, in a more dynamically active cluster or a cluster with a
higher density ICM, such a process would lead to passive spirals and/or S0s.


title:
The effect of photo-ionization on the cooling rates of enriched,
  astrophysical plasmas

abstract:
  Radiative cooling is central to a wide range of astrophysical problems.
Despite its importance, cooling rates are generally computed using very
restrictive assumptions, such as collisional ionization equilibrium and solar
relative abundances. We simultaneously relax both assumptions and investigate
the effects of photo-ionization of heavy elements by the meta-galactic UV/X-ray
background and of variations in relative abundances on the cooling rates of
optically thin gas in ionization equilibrium. We find that photo-ionization by
the meta-galactic background radiation reduces the net cooling rates by up to
an order of magnitude for gas densities and temperatures typical of the
shock-heated intergalactic medium and proto-galaxies. In addition,
photo-ionization changes the relative contributions of different elements to
the cooling rates. We conclude that photo-ionization by the ionizing background
and heavy elements both need to be taken into account in order for the cooling
rates to be correct to order of magnitude. Moreover, if the rates need to be
known to better than a factor of a few, then departures of the relative
abundances from solar need to be taken into account. We propose a method to
compute cooling rates on an element-by-element basis by interpolating
pre-computed tables that take photo-ionization into account. We provide such
tables for a popular model of the evolving UV/X-ray background radiation,
computed using the photo-ionization package CLOUDY.


title: Multifractality of self-avoiding walks on percolation clusters

abstract:
  We consider self-avoiding walks (SAWs) on the backbone of percolation
clusters in space dimensions d=2, 3, 4. Applying numerical simulations, we show
that the whole multifractal spectrum of singularities emerges in exploring the
peculiarities of the model. We obtain estimates for the set of critical
exponents, that govern scaling laws of higher moments of the distribution of
percolation cluster sites visited by SAWs, in a good correspondence with an
appropriately summed field-theoretical \varepsilon=6-d-expansion (H.-K. Janssen
and O. Stenull, Phys. Rev. E 75, 020801(R) (2007)).


title:
Mott and Wigner-Mott transitions in doped correlated electron systems:
  effects of superlattice potential and inter-site correlation

abstract:
  We introduce the notion of superstructure Mottness to describe the Mott and
Wigner-Mott transition in doped strongly correlated electron systems at
commensurate filling fractions away from one electron per site. We show that
superstructure Mottness emerges in an inhomogeneous electron system when the
superstructure contains an odd number of electrons per supercell. We argue that
superstructure Mottness exists even in the absence of translation symmetry
breaking by a superlattice, provided that the extended or intersite Coulomb
interaction is strong. In the latter case, superstructure Mottness offers a
unifying framework for the Mott and Wigner physics and a nonperturbative,
strong coupling description of the Wigner-Mott transition. We support our
proposal by studying a minimal single-band ionic Hubbard $t$-$U$-$V$-$\Delta$
model with nearest neighbor Coulomb repulsion $V$ and a two-sublattice ionic
potential $\Delta$. The model is mapped onto a Hubbard model with two effective
``orbitals'' representing the two sites within the supercell, the intra and
interorbital Coulomb repulsion $U$ and $U^\prime \sim V$, and a crystal field
splitting $\Delta$. Charge order on the original lattice corresponds to orbital
order. Developing a cluster Gutzwiller approximation, we study the effects and
the interplay between $V$ and $\Delta$ on the Mott and Wigner-Mott transitions
at quarter-filling. We provide the mechanism by which the superlattice
potential enhances the correlation effects and the tendency towards local
moment formation, construct and elucidate the phase diagram in the unifying
framework of superstructure Mottness.


title:
Security of Binary Modulated Continuous Variable Quantum Key
  Distribution under Collective Attacks

abstract:
  We give an achievable secret key rate of a binary modulated continuous
variable quantum key distribution schemes in the collective attack scenario
considering quantum channels that impose arbitrary noise on the exchanged
signals. Bob performs homodyne measurements on the received states and the two
honest parties employ a reverse reconciliation procedure in the classical
post-processing step of the protocol.


title:
A Spectroscopic and Photometric Study of the Metal-Poor, Pulsating,
  Post-AGB Binary HD 46703

abstract:
  The metal-poor post-AGB star HD 46703 is shown to be a single-line
spectroscopic binary with a period of 600 days, a high velocity of -94 km/s,
and an orbital eccentricity of 0.3. Light curve studies show that it also
pulsates with a period of 29 days. High-resolution, high signal-to-noise
spectra were used for a new abundance study. The atmospheric model determined
is T(eff) = 6250 K, log(g) = 1.0, V(t) = 3.0 km/s, and a metal abundance of
[M/H] = -1.5. A low carbon abundance and lack of s-process element enhancement
indicate that the star has not experienced third dredge-up on the AGB. The
sulfur and zinc abundances are high compared with iron, and the chemical
abundances show a clear anti-correlation with condensation temperature. The
abundance depletion pattern is similar to that seen in other post-AGB binaries,
and, like them, is attributed to the chemical fractionation of refractory
elements onto dust stored in a circumbinary disk and the re-accretion of
volatiles in the stellar atmosphere. The infrared excess is small but the
excess energy distribution is very similar to what can expected from a disk. HD
46703 joins the growing list of depleted, post-AGB stars which are likely
surrounded by a dusty and stable circumbinary disk.


title: Non-commutative quadrics

abstract:
  In this paper we describe non-commutative versions of $\PP^1\times \PP^1$.
These contain the class of non-commutative deformations of $\PP^1\times \PP^1$.


title:
The last stages of evolution of close binaries composed of compact
  companions

abstract:
  Gamma-ray bursts (GRB) are the most powerful transient phenomena in the
Universe. Nowadays dozens of speculations on the origin of GRB were undertaken,
but so far a single model for the origin of, in particular, short GRBs does not
exist. The black hole (BH) - neutron star (NS) coalescence is a promising
candidate source for short GRBs. Most of binary mergers numerical simulations
were carried out with the purpose of investigating the emission of
gravitational waves. Such a scenario consists of an inspiral, merging and
ringdown phase. In this paper we present the comparison of the observational
results and analytical predictions for a test particle in a quasicircular orbit
around the BH. The emission of gravitational waves causes a rapid decrease of
the orbital radius and a rise of a {\it chirp} of radiation. Matter orbiting
the black hole would be expected to produce high-frequency oscillations (HFO).
Timescales of the coalescence process are of the order of milliseconds and
oscillation frequencies of hundreds Hz for a system with a solar mass BH
companion. We report on the detection of HFO in two short gamma-ray bursts in
this paper. The frequencies and durations of the oscillations are in agreement
with the predicted values. A {\it chirp} phenomenon is identified also. We
therefore argue in favor of BH-NS mergers as a scenario for the production of
short gamma-ray bursts.


title: Approximating Document Frequency with Term Count Values

abstract:
  For bounded datasets such as the TREC Web Track (WT10g) the computation of
term frequency (TF) and inverse document frequency (IDF) is not difficult.
However, when the corpus is the entire web, direct IDF calculation is
impossible and values must instead be estimated. Most available datasets
provide values for term count (TC) meaning the number of times a certain term
occurs in the entire corpus. Intuitively this value is different from document
frequency (DF), the number of documents (e.g., web pages) a certain term occurs
in. We conduct a comparison study between TC and DF values within the Web as
Corpus (WaC). We found a very strong correlation with Spearman's rho >0.8
(p<0.005) which makes us confident in claiming that for such recently created
corpora the TC and DF values can be used interchangeably to compute IDF values.
These results are useful for the generation of accurate lexical signatures
based on the TF-IDF scheme.


title: Generalized Cantor manifolds and homogeneity

abstract:
  A classical theorem of Alexandroff states that every $n$-dimensional
compactum $X$ contains an $n$-dimensional Cantor manifold. This theorem has a
number of generalizations obtained by various authors. We consider
extension-dimensional and infinite dimensional analogs of strong Cantor
manifolds, Mazurkiewicz manifolds, and $V^n$-continua, and prove corresponding
versions of the above theorem. We apply our results to show that each
homogeneous metrizable continuum which is not in a given class $\mathcal C$ is
a strong Cantor manifold (or at least a Cantor manifold) with respect to
$\mathcal C$. Here, the class $\mathcal C$ is one of four classes that are
defined in terms of dimension-like invariants.
  A class of spaces having bases of neighborhoods satisfying certain special
conditions is also considered.


title: Inclusive chi_bJ(nP) Decays to D0 X

abstract:
  Using Upsilon(2S) and Upsilon(3S) data collected with the CLEO III detector
we have searched for decays of chi_bJ to final states with open charm. We fully
reconstruct D0 mesons with p_D0 > 2.5 GeV/c in three decay modes (K-pi+,
K-pi+pi0, and K-pi-pi+pi+) in coincidence with radiative transition photons
that tag the production of one of the chi_bJ(nP) states. We obtain significant
signals for the two J=1 states. Recent NRQCD calculations of chi_{bJ}(nP) --> c
cbar X depend on one non-perturbative parameter per chi_bJ triplet. The
extrapolation from the observed D0 X rate over a limited momentum range to a
full c cbar X rate also depends on these same parameters. Using our data to fit
for these parameters, we extract results which agree well with NRQCD
predictions, confirming the expectation that charm production is largest for
the J=1 states. In particular, for J=1, our results are consistent with c cbar
g accounting for about one-quarter of all hadronic decays.


title: Searching direction dependent daily modulation in dark matter detectors

abstract:
  Channeling of recoil ions in various crystals strongly depends on their
direction. This, along with the WIMP wind due to the rotation of the galactic
disc generates {\it daily} modulations of the channeling. Since channeling
affect the characteristics of the WIMP induced recoil events these modulations
may be observed in single crystal detectors and serve as a WIMP signature. We
suggest in particular searching for such modulations in the DAMA scintillation
data.


title: Modular Invariants and Twisted Equivariant K-theory

abstract:
  Freed-Hopkins-Teleman expressed the Verlinde algebra as twisted equivariant
K-theory. We study how to recover the full system (fusion algebra of defect
lines), nimrep (cylindrical partition function), etc of modular invariant
partition functions of conformal field theories associated to loop groups. We
work out several examples corresponding to conformal embeddings and orbifolds.
We identify a new aspect of the A-D-E pattern of SU(2) modular invariants.


title:
Air Fluorescence Relevant for Cosmic-Ray Detection - Summary of the 5th
  Fluorescence Workshop, El Escorial 2007

abstract:
  High-energy cosmic rays with energies exceeding $10^{17}$ eV are frequently
observed by measurements of the fluorescence light induced by air showers. A
major contribution to the systematic uncertainties of the absolute energy scale
of such experiments is the insufficient knowledge of the fluorescence light
yield of electrons in air. The aim of the 5th Fluorescence Workshop was to
bring together experimental and theoretical expertise to discuss the latest
progress on the investigations of the fluorescence light yield. The results of
the workshop will be reviewed as well as the present status of knowledge in
this field. Emphasis is given to the fluorescence light yield important for air
shower observations and its dependence on atmospheric parameters, like
pressure, temperature, and humidity. The effects of the latest results on the
light observed from air showers will be discussed.


title: On a generalized Jones conjecture

abstract:
  We solve the Jones conjecture, which states that the exponent sum in a
minimal braid representation of a knot in S^3 is a knot invariant, by proving a
generalized version of the original one. We apply contact geometry to study
this problem in knot theory.


title:
The Size Distributions of Asteroid Families in the SDSS Moving Object
  Catalog 4

abstract:
  Asteroid families, traditionally defined as clusters of objects in orbital
parameter space, often have distinctive optical colors. We show that the
separation of family members from background interlopers can be improved with
the aid of SDSS colors as a qualifier for family membership. Based on an
~88,000 object subset of the Sloan Digital Sky Survey Moving Object Catalog 4
with available proper orbital elements, we define 37 statistically robust
asteroid families with at least 100 members using a simple Gaussian
distribution model in both orbital and color space. The interloper rejection
rate based on colors is typically ~10% for a given orbital family definition,
with four families that can be reliably isolated only with the aid of colors.
About 50% of all objects in this data set belong to families, and this fraction
varies from about 35% for objects brighter than an H magnitude of 13 and rises
to 60% for objects fainter than this. The fraction of C-type objects in
families decreases with increasing H magnitude for H > 13, while the fraction
of S-type objects above this limit remains effectively constant. This suggests
that S-type objects require a shorter timescale for equilibrating the
background and family size distributions via collisional processing. The size
distributions for 15 families display a well-defined change of slope and can be
modeled as a "broken" double power-law. Such "broken" size distributions are
twice as likely for S-type familes than for C-type families, and are dominated
by dynamically old families. The remaining families with size distributions
that can be modeled as a single power law are dominated by young families. When
size distribution requires a double power-law model, the two slopes are
correlated and are steeper for S-type families.


title:
Single-valley high-mobility (110) AlAs quantum wells with anisotropic
  mass

abstract:
  We studied a doping series of (110)-oriented AlAs quantum wells (QWs) and
observed transport evidence of single anisotropic-mass valley occupancy for the
electrons in a 150 \AA wide QW. Our calculations of strain and quantum
confinement for these samples predict single anisotropic-mass valley occupancy
for well widths $W$ greater than 53 \AA. Below this, double-valley occupation
is predicted such that the longitudinal mass axes are collinear. We observed
mobility anisotropy in the electronic transport along the crystallographic
directions in the ratio of 2.8, attributed to the mass anisotropy as well as
anisotropic scattering of the electrons in the X-valley of AlAs.


title:
Local Well-posedness and a priori bounds for the modified Benjamin-Ono
  equation without using a gauge transformation

abstract:
  We prove that the complex-valued modified Benjamin-Ono (mBO) equation is
locally wellposed if the initial data $\phi$ belongs to $H^s$ for $s\geq 1/2$
with $\norm{\phi}_{L^2}$ sufficiently small without performing a gauge
transformation. Hence the real-valued mBO equation is globally wellposed for
those initial datas, which is contained in the results of C. Kenig and H.
Takaoka \cite{KenigT} where the smallness condition is not needed. We also
prove that the real-valued $H^\infty$ solutions to mBO equation satisfy a
priori local in time $H^s$ bounds in terms of the $H^s$ size of the initial
data for $s>1/4$.


title:
N-body + Magnetohydrodynamical Simulations of Merging Clusters of
  Galaxies: Characteristic Magnetic Field Structures Generated by Bulk Flow
  Motion

abstract:
  We present results from N-body + magnetohydrodynamical simulations of merging
clusters of galaxies. We find that cluster mergers cause various characteristic
magnetic field structures because of the strong bulk flows in the intracluster
medium. The moving substructures result in cool regions surrounded by the
magnetic field. These will be recognized as magnetized cold fronts in the
observational point of view. A relatively ordered magnetic field structure is
generated just behind the moving substructure. Eddy-like field configurations
are also formed by Kelvin-Helmholtz instabilities. These features are similarly
seen even in off-center mergers though the detailed structures change slightly.
The above-mentioned characteristic magnetic field structures are partly
recognized in Faraday rotation measure maps. The higher absolute values of the
rotation measure are expected when observed along the collision axis, because
of the elongated density distribution and relatively ordered field structure
along the axis. The rotation measure maps on the cosmic microwave background
radiation, which covers clusters entirely, could be useful probes of not only
the magnetic field structures but also the internal dynamics of the
intracluster medium.


title: On the unipotent characters of the Ree groups of type G_2

abstract:
  This note is concerned with the unipotent characters of the Ree groups of
type G_2. We determine the roots of unity associated by Lusztig and
Digne-Michel to unipotent characters of ^2G_2(3^{2n+1}) and we prove that the
Fourier matrix of ^2G_2(3^{2n+1}) defined by Geck and Malle satisfies a
conjecture of Digne-Michel. Our main tool is the Shintani descent of Ree groups
of type G_2.


title:
Transiting exoplanets from the CoRoT space mission IV: CoRoT-Exo-4b: A
  transiting planet in a 9.2 day synchronous orbit

abstract:
  CoRoT, the first space-based transit search, provides ultra-high precision
light curves with continuous time-sampling over periods, of up to 5 months.
This allows the detection of transiting planets with relatively long periods,
and the simultaneous study of the host star's photometric variability. In this
letter, we report on the discovery of the transiting giant planet CoRoT-Exo-4b
and use the CoRoT light curve to perform a detailed analysis of the transit and
to determine the stellar rotation period. The CoRoT light curve was
pre-processed to remove outliers and correct for orbital residuals and
artefacts due to hot pixels on the detector. After removing stellar variability
around each transit, the transit light curve was analysed to determine the
transit parameters. A discrete auto-correlation function method was used to
derive the rotation period of the star from the out-of-transit light curve. We
derive periods for the planet's orbit and star's rotation of 9.20205 +/-
0.00037 and 8.87 +/- 1.12 days respectively, consistent with a synchronised
system. We also derive the inclination, i = 90.00 -0.085 +0.000 in degrees, the
ratio of the orbital distance to the stellar radius, a/R_s = 17.36 -0.25 +0.05,
and the planet to star radius ratio R_p/R_s = 0.1047 -0.0022 +0.0041. We
discuss briefly the coincidence between the orbital period of the planet and
the stellar rotation period and its possible implications for the system's
migration and star-planet interaction history.


title:
Dynamic Data Compression with Distortion Constraints for Wireless
  Transmission over a Fading Channel

abstract:
  We consider a wireless node that randomly receives data from different sensor
units. The arriving data must be compressed, stored, and transmitted over a
wireless link, where both the compression and transmission operations consume
power. Specifically, the controller must choose from one of multiple
compression options every timeslot. Each option requires a different amount of
power and has different compression ratio properties. Further, the wireless
link has potentially time-varying channels, and transmission rates depend on
current channel states and transmission power allocations. We design a dynamic
algorithm for joint compression and transmission, and prove that it comes
arbitrarily close to minimizing average power expenditure, with an explicit
tradeoff in average delay. Our approach uses stochastic network optimization
together with a concept of place holder bits to provide efficient energy-delay
performance. The algorithm is simple to implement and does not require
knowledge of probability distributions for packet arrivals or channel states.
Extensions that treat distortion constraints are also considered.


title: Dark Matter Annihilation and Primordial Star Formation

abstract:
  We investigate the effects of weakly-interacting massive particle (WIMP) dark
matter annihilation on the formation of Population III.1 stars, which are
theorized to form from the collapse of gas cores at the centers of dark matter
minihalos. We consider the relative importance of cooling due to baryonic
radiative processes and heating due to WIMP annihilation. We analyze the dark
matter and gas profiles of several halos formed in cosmological-scale numerical
simulations. The heating rate depends sensitively on the dark matter density
profile, which we approximate with a power law rho_chi ~ r^{-alpha_chi}, in the
numerically unresolved inner regions of the halo. If we assume a self-similar
structure so that alpha_chi ~= 1.5 as measured on the resolved scales ~1pc,
then for a fiducial WIMP mass of 100GeV, the heating rate is typically much
smaller (<10^{-3}) than the cooling rate for densities up to
n_H=10^{17}cm^{-3}. In one case, where alpha_chi=1.65, the heating rate becomes
similar to the cooling rate by a density of n_H=10^{15}cm^{-3}. The dark matter
density profile is expected to steepen in the central baryon-dominated region
<~1pc due to adiabatic contraction, and we observe this effect (though with
relatively low resolution) in our numerical models. From these we estimate
alpha_chi~=2.0. The heating now dominates cooling above n_H~=10^{14}cm^{-3}, in
agreement with the previous study of Spolyar, Freese & Gondolo. We expect this
leads to the formation of an equilibrium structure with a baryonic and dark
matter density distribution exhibiting a flattened central core. Examining such
equilibria, we find total luminosities due to WIMP annihilation are relatively
constant and ~10^3 L_sun, set by the radiative luminosity of the baryonic core.
We discuss the implications for Pop III.1 star formation... (abridged)


title:
General Rule and Materials Design of Negative Effective U System for
  High-T_c Superconductivity

abstract:
  Based on the microscopic mechanisms of (1) charge-excitation-induced negative
effective U in s^1 or d^9 electronic configurations, and (2)
exchange-correlation-induced negative effective U in d^4 or d^6 electronic
configurations, we propose a general rule and materials design of negative
effective U system in itinerant (ionic and metallic) system for the realization
of high-T_c superconductors. We design a T_c-enhancing layer (or clusters) of
charge-excitation-induced negative effective $U$ connecting the superconducting
layers for the realistic systems.


title:
Astrometry of the Dynamical Ejection of the Becklin-Neugebauer Object
  from theta^1 Ori C

abstract:
  We show that the proper motion of the Becklin-Neugebauer (BN) object is
consistent with its dynamical ejection from the theta^1 Ori C binary, contrary
to recent claims by Gomez et al. Continued radio observations of BN and future
precise astrometric observations of theta^1 Ori C with SIM and the Orion Nebula
Cluster with GAIA can constrain the properties of this ejection event, with
implications for theories of how the nearest example of massive star formation
is proceeding.


title: Reactive Rayleigh-Taylor Turbulence

abstract:
  The Rayleigh-Taylor (RT) instability develops and leads to turbulence when a
heavy fluid falls under the action of gravity through a light one. We consider
this phenomenon accompanied by a reactive transformation between the fluids,
and study with Direct Numerical Simulations (DNS) how the reaction (flame)
affects the turbulent mixing in the Boussinesq approximation. We discuss "slow"
reactions where the characteristic reaction time exceeds the temporal scale of
the RT instability. In the early turbulent stage, effects of the flame are
distributed over a maturing mixing zone, whose development is weakly influenced
by the reaction. At later times, the fully mixed zone transforms into a
conglomerate of pure-fluid patches of sizes proportional to the mixing zone
width. In this "stirred flame'' regime, temperature fluctuations are consumed
by reactions in the regions separating the pure-fluid patches. This DNS-based
qualitative description is followed by a phenomenology suggesting that thin
turbulent flame is of a single-fractal character, and thus distribution of the
temperature field is strongly intermittent.


title: Synchrotron Self-Compton Model for PKS 2155-304

abstract:
  H.E.S.S. observed TeV blazar PKS 2155--304 in a strong flare state in 2006
July. The TeV flux varied on timescale as short as a few minutes, which sets
strong constraints on the properties of the emission region. By use of the
synchrotron self-Compton model, we found that models with the bulk Lorentz
factor $\sim 100$, the size of the emission region $\sim 10^{15}$ cm, and
magnetic field $\sim 0.1$ G explain the observed spectral energy distribution
and the flare timescale $\sim$ a few minutes. This model with a large value of
$\Gamma$ accounts for the emission spectrum not only in the TeV band but also
in the X-ray band. The major cooling process of electrons/positrons in the jet
is inverse Compton scattering off synchrotron photons. The energy content of
the jet is highly dominated by particle kinetic energy over magnetic energy.


title: The MagE Spectrograph

abstract:
  The Magellan Echellette (MagE) spectrograph is a single-object optical
echellette spectrograph for the Magellan Clay telescope. MagE has been designed
to have high throughput in the blue; the peak throughput is 22% at 5600 A
including the telescope. The wavelength coverage includes the entire optical
window (3100 A - 1 micron). The spectral resolution for a 1" slit is R~4100.
MagE is a very simple spectrograph with only four moving parts, prism
cross-dispersion, and a vacuum Schmidt camera. The instrument saw first light
in November 2007 and is now routinely taking science observations.


title: Looking up at seesaw and GUT scales from TeV

abstract:
  In this talk, I discuss how we may approach physics at the seesaw- and
GUT-scales using data from the TeV scale. Even though we cannot hope to
directly reach these energy scales using particle accelerators, we may get
convinced of grand unification and seesaw mechanism based on experimental data
if Nature is kind to us. In addition, we may find compelling reason to believe
in leptogenesis based on experimental data. This cannot be achieved by a single
experiment, but rather a collection of them, based on LHC, ILC, neutrino
oscillation, neutrinoless double beta decay, direct dark matter detection, CMB
power spectrum and its tensor mode.


title:
Band structure asymmetry of bilayer graphene revealed by infrared
  spectroscopy

abstract:
  We report on infrared spectroscopy of bilayer graphene integrated in gated
structures. We observed a significant asymmetry in the optical conductivity
upon electrostatic doping of electrons and holes. We show that this finding
arises from a marked asymmetry between the valence and conduction bands, which
is mainly due to the inequivalence of the two sublattices within the graphene
layer. From the conductivity data, the energy difference of the two sublattices
is determined.


title: The FourStar Infrared Camera

abstract:
  The FourStar infrared camera is a 1.0-2.5 micron (JHKs) near infrared camera
for the Magellan Baade 6.5m telescope at Las Campanas Observatory (Chile). It
is being built by Carnegie Observatories and the Instrument Development Group
at Johns Hopkins and is scheduled for completion in 2009. The instrument uses
four Teledyne HAWAII-2RG arrays that produce a 10.9 x 10.9 arcmin field of
view. The outstanding seeing at the Las Campanas site coupled with FourStar's
high sensitivity and large field of view will enable many new survey and
targeted science programs.


title: Newtonian limit of nonlocal cosmology

abstract:
  We study the consequences of the $f(R/\Box)$ gravity models for the Solar
system and the large scale structure of the universe. The spherically symmetric
solutions can be used to obtain bounds on the constant and the linear parts of
the correction terms. The evolution of cosmological matter structures is shown
to be governed by an effective time dependent Newton's constant. We also
analyze the propagation of the perturbation modes. Tensor and vector modes are
only slightly modified, but two new scalar degrees of freedom are present.
Their causality and stability is demonstrated, and their formal ghost
conditions are related to a singularity of the cosmological background. In
general, the Newtonian limit of these models has no apparent conflicts with
observations but can provide useful constraints.


title: Contest based on a directed polymer in a random medium

abstract:
  We introduce a simple one-parameter game derived from a model describing the
properties of a directed polymer in a random medium. At his turn, each of the
two players picks a move among two alternatives in order to maximize his final
score, and minimize opponent's return. For a game of length $n$, we find that
the probability distribution of the final score $S_n$ develops a traveling wave
form, ${\rm Prob}(S_n=m)=f(m-v n)$, with the wave profile $f(z)$ unusually
decaying as a double exponential for large positive and negative $z$. In
addition, as the only parameter in the game is varied, we find a transition
where one player is able to get his maximum theoretical score. By extending
this model, we suggest that the front velocity $v$ is selected by the nonlinear
marginal stability mechanism arising in some traveling wave problems for which
the profile decays exponentially, and for which standard traveling wave theory
applies.


title: Dirac charge dynamics in graphene by infrared spectroscopy

abstract:
  A remarkable manifestation of the quantum character of electrons in matter is
offered by graphene, a single atomic layer of graphite. Unlike conventional
solids where electrons are described with the Schrodinger equation, electronic
excitations in graphene are governed by the Dirac Hamiltonian. Some of the
intriguing electronic properties of graphene, such as massless Dirac
quasiparticles with linear energy-momentum dispersion, have been confirmed by
recent observations. Here we report an infrared (IR) spectromicroscopy study of
charge dynamics in graphene integrated in gated devices. Our measurements
verify the expected characteristics of graphene and, owing to the previously
unattainable accuracy of IR experiments, also uncover significant departures of
the quasiparticle dynamics from predictions made for Dirac fermions in
idealized, free standing graphene. Several observations, including a marked
deviation of the energy bands from the simple linear dispersion, point to the
relevance of many body interactions to the rather exotic electromagnetic
response in graphene.


title:
Evidence for Strong Itinerant Spin Fluctuations in the Normal State of
  CeFeAsO(0.89)F(0.11) Iron-Oxypnictides

abstract:
  The electronic structure in the normal state of CeFeAsO0.89F0.11 oxypnictide
superconductors has been investigated with x-ray absorption and photoemission
spectroscopy. All the data exhibit signatures of Fe d-electron itinerancy.
Exchange multiplets appearing in the Fe 3s core level indicate the presence of
itinerant spin fluctuations. These findings suggest that the underlying physics
and the origin of superconductivity in these materials are likely to be quite
different from those of the cuprate high-temperature superconductors. These
materials provide opportunities for elucidating the role of magnetic
fluctuations in high-temperature superconductivity.


title:
Adiabatic limit, Bismut-Freed connection, and the real analytic torsion
  form

abstract:
  For a complex flat vector bundle over a fibered manifold, we consider the
1-parameter family of certain deformed sub-signature operators introduced by
Ma-Zhang. We compute the adiabatic limit of the Bismut-Freed connection
associated to this family and show that the Bismut-Lott analytic torsion form
shows up naturally under this procedure.


title:
Helioseismic analysis of the solar flare-induced sunquake of 2005
  January 15. II: A magneto-seismic study

abstract:
  On 2005 January 15, the active region AR10720 produced an X1.2 solar flare
that induced high levels of seismicity into the photospheric layers. The
seismic source was detected using helioseismic holography and analysed in
detail in Paper I. Egression power maps at 6 mHz with a 2 mHz bandwidth
revealed a compact acoustic source strongly correlated with the footpoints of
the coronal loop that hosted the flare. We present a magneto-seismic study of
this active region in order to understand, for the first time, the magnetic
topological structure of a coronal field that hosts an acoustically active
solar flare. The accompanying analysis attempts to answer questions such as:
Can the magnetic field act as a barrier and prevent seismic waves from
spreading away from the focus of the sunquake? And, what is the most efficient
magnetic structure that would facilitate the development of a strong seismic
source in the photosphere?


title:
The Quantum Hall Transition in Real Space: From Localized to Extended
  States

abstract:
  Using scanning tunneling spectroscopy in ultra-high vacuum at low temperature
(T = 0.3 K) and high magnetic fields (B < 12 T), we directly probe electronic
wave functions across an integer quantum Hall transition. In accordance with
theoretical predictions, we observe the evolution from localized drift states
in the insulating phases to branched extended drift states at the quantum
critical point. The observed microscopic behavior close to the extended state
indicates points of localized quantum tunneling, which are considered to be
decisive for a quantitative description of the transition.


title: Mach's relativity of rotation in light of contemporary physics

abstract:
  Mach argued for a relational rather than an absolute notion of space,
insisting that centrifugal forces inside a rotating object such as a bucket can
be reproduced by keeping the bucket fixed and rotating the universe. In
response to a paper of ours denying the validity of Mach's views, Bhadra and
Das elaborate on Mach's position. We address several of their arguments and
show that Mach's relational notion of space is wrong-headed. Special and
general relativity distinguish between a bucket (i.e. any system) rotating in a
fixed universe and a bucket fixed in a rotating universe and between a
non-rotating bucket in a non-rotating universe and a co-rotating bucket in a
rotating universe, distinctions that go against Mach's relational theory of
space. Even when taken on its own terms, Mach's theory can apply only to single
point-like buckets rotating at infinitesimal angular velocities.


title:
Fishtail effect and the vortex phase diagram of single crystal
  Ba0.6K0.4Fe2As2

abstract:
  By measuring the magnetization hysteresis loops of superconducting
Ba0.6K0.4Fe2As2 single crystals, we obtained the high upper critical field and
large current carrying ability, which point to optimistic applications. The
fishtail (or second peak) effect is also found in the material, and the
position of the vortex pinning force shows a maximum at 1/3 of the reduced
field, being consistent with the picture of vortex pinning by small size normal
cores in the sample. Together with the resistive measurements, for the first
time the vortex phase diagram is obtained for superconductor Ba0.6K0.4Fe2As2.


title:
The branch processes of vortex filaments and Hopf Invariant Constraint
  on Scroll Wave

abstract:
  In this paper, by making use of Duan's topological current theory, the
evolution of the vortex filaments in excitable media is discussed in detail.
The vortex filaments are found generating or annihilating at the limit points
and encountering, splitting, or merging at the bifurcation points of a complex
function $Z(\vec{x},t)$. It is also shown that the Hopf invariant of knotted
scroll wave filaments is preserved in the branch processes (splitting, merging,
or encountering) during the evolution of these knotted scroll wave filaments.
Furthermore, it also revealed that the "exclusion principle" in some chemical
media is just the special case of the Hopf invariant constraint, and during the
branch processes the "exclusion principle" is also protected by topology.


title:
First Order Phase Transition and Superconductivity in BaNi2As2 Single
  Crystals

abstract:
  We report the synthesis and physical properties of single crystals of
stoichiometric BaNi2As2 that crystalizes in the ThCr2Si2 structure with lattice
parameters a = 4.112(4) \AA and c = 11.54(2) \AA. Resistivity and heat capacity
show a first order phase transition at T_0 = 130 K with a thermal hysteresis of
7 K. The Hall coefficient is weakly temperature dependent from room temperature
to 2 K where it has a value of -4x10^{-10} \Omega-cm/Oe. Resistivity,
ac-susceptibility, and heat capacity find evidence for bulk superconductivity
at T_c = 0.7 K. The Sommerfeld coefficient at T_c is 11.6 \pm 0.9 mJ/molK^2.
The upper critical field is anisotropic with initial slopes of dH_{c2}^{c}/dT =
-0.19 T/K and dH_{c2}^{ab}/dT = -0.40 T/K, as determined by resistivity.


title:
Nature of Stripes in the Generalized t-J Model Applied to The Cuprate
  Superconductors

abstract:
  Recent transport properties on the stripe phase in
La$_{\text{1.875}}$Ba$_{\text{01.25}}$CuO$_{\text{4}}$ by Li \textit{et al.}
found 2-dimensional superconductivity over a wide temperature range including a
Berezinski-Kosterlitz-Thouless transition at a temperature T=16K, with
3-dimensional superconducting (SC) ordering only at T=4K. These results
contradict the long standing belief that the onset of superconductivity is
suppressed by stripe ordering and suggest coexistence of stripe and SC phases.
The lack of 3-D superconducting order above T=4K requires an antiphase ordering
in the SC state to suppress the interlayer Josephson coupling as proposed by
Berg \textit{et al.}. Here we use a renormalized mean field theory for a
generalized t-J model to examine in detail the energetics of the spin and
charge stripe ordered SC states including possible antiphase domains in the SC
order. We find that the energies of these modulated states are very close to
each other and that the anisotropy present in the low temperature tetragonal
crystal structure favors stripe resonating valence bond states. The stripe
antiphase SC states are found to have energies very close,but always above, the
ground state energy which suggests additional physical effects are responsible
for their stability.


title:
Nonlinear Quantum Neuro-Psycho-Dynamics with Topological Phase
  Transitions

abstract:
  We have proposed a novel model of general quantum, stochastic and chaotic
psychodynamics. The model is based on the previously developed Life-Space Foam
(LSF) framework to motivational and cognitive dynamics. The present model
extends the LSF-approach by incorporating chaotic and topological
non-equilibrium phase transitions. Such extended LSF-model is applied for
rigorous description of multi-agent joint action. The present model is related
to Haken-Kelso-Bunz model of self-organization in the human motor system
(including: multi-stability, phase transitions and hysteresis effects,
presenting a contrary view to the purely feedback driven neural systems), as
well as the entropy-approach to adaptation in human goal-directed motor
control.
  Keywords: Quantum probability, Life-Space Foam, noisy decision making, chaos,
topological phase transitions, multi-agent joint action, goal-directed motor
control


title:
Low energy theorem for virtual Compton scattering and generalized sum
  rules of the nucleon

abstract:
  We formulate the low energy theorem for virtual Compton scattering off a
nucleon and examine its consequences for generalized nucleon polarizabilites.
As a result of a new, model independent definition of the low energy limit for
VVCS reaction, all generalized sum rules of the nucleon have continuous limit
for real photons and obtain contributions from the $t$-channel that were not
included previously.


title: Radio-Loud QSOs and Sub-Millimeter Galaxies: Space Distributions

abstract:
  A picture has emerged connecting QSOs with Sub-Millimetre Galaxies (SMGs)
through an evolutionary sequence in which forming galaxies are initially
FIR-luminous but X-ray weak, similar to known SMGs. As the black hole and
spheroid grow with time, the central QSO becomes powerful enough to terminate
star formation and eject much of the fuel supply. The unobscured QSO activity
subsequently declines to leave a quiescent spheroidal galaxy. Here I describe
parallel investigations of space density, one for a sample of radio-loud QSOs
(RQSOs), and a second for SMGs. Each class shows both cosmic down-sizing and a
redshift cutoff. The coincidence in apparent epoch of creation is marked; if it
does not prove a causal connection, it is at least circumstantial evidence that
the foregoing sequence is correct.


title: Theoretical calculations for solid oxygen under high pressure

abstract:
  The crystal structure of solid oxygen at low temperatures and at pressures up
to 7 GPa is studied by theoretical calculations. In the calculations, the
adiabatic potential of the crystal is approximated by a superposition of
pair-potentials between oxygen molecules calculated by an ab-initio method. The
monoclinic alpha structure is stable up to 6 GPa and calculated lattice
parameters agree well with experiments. The origin of a distortion and that of
an anisotropic lattice compressibility of the basal plane of alpha-O2 are
clearly demonstrated. In the pressure range from 6 to 7 GPa, two kinds of
structures are proposed by X-ray diffraction experiments: the alpha and
orthorhombic delta structures. It is found that the energy difference between
these structures becomes very small in this pressure range. The relation
between this trend and the incompatible results of X-ray diffraction
experiments is discussed.


title:
A multi-site campaign to measure solar-like oscillations in Procyon. I.
  Observations, Data Reduction and Slow Variations

abstract:
  We have carried out a multi-site campaign to measure oscillations in the F5
star Procyon A. We obtained high-precision velocity observations over more than
three weeks with eleven telescopes, with almost continuous coverage for the
central ten days. This represents the most extensive campaign so far organized
on any solar-type oscillator. We describe in detail the methods we used for
processing and combining the data. These involved calculating weights for the
velocity time series from the measurement uncertainties and adjusting them in
order to minimize the noise level of the combined data. The time series of
velocities for Procyon shows the clear signature of oscillations, with a
plateau of excess power that is centred at 0.9 mHz and is broader than has been
seen for other stars. The mean amplitude of the radial modes is 38.1 +/- 1.3
cm/s (2.0 times solar), which is consistent with previous detections from the
ground and by the WIRE spacecraft, and also with the upper limit set by the
MOST spacecraft. The variation of the amplitude during the observing campaign
allows us to estimate the mode lifetime to be 1.5 d (+1.9/-0.8 d). We also find
a slow variation in the radial velocity of Procyon, with good agreement between
different telescopes. These variations are remarkably similar to those seen in
the Sun, and we interpret them as being due to rotational modulation from
active regions on the stellar surface. The variations appear to have a period
of about 10 days, which presumably equals the stellar rotation period or,
perhaps, half of it. The amount of power in these slow variations indicates
that the fractional area of Procyon covered by active regions is slightly
higher than for the Sun.


title: Relational Lattice Axioms

abstract:
  Relational lattice is a formal mathematical model for Relational algebra. It
reduces the set of six classic relational algebra operators to two: natural
join and inner union. We continue to investigate Relational lattice properties
with emphasis onto axiomatic definition. New results include additional axioms,
equational definition for set difference (more generally anti-join), and case
study demonstrating application of the relational lattice theory for query
transformations.


title:
Spectral, Spatial, and Time properties of the hydrogen nebula around
  exoplanet HD209458b

abstract:
  All far ultraviolet observations of HD209458 tend to support a scenario in
which the inflated hydrogen atmosphere of its planetary companion strongly
absorbs the stellar \lya flux during transit. However, it was not clear how the
transit absorption depends on the selected wavelength range in the stellar line
profile, nor how the atomic hydrogen cloud was distributed spatially around
HD209458b. Here we report a sensitivity study of observed time and spectral
variations of the stellar flux. In particular, the sensitivity of the
absorption depth during transit to the assumed spectral range in the stellar
line profile is shown to be very weak, leading to a transit depth in the range
$(8.4-8.9)%\pm 2.0%$ for all possible wavelength ranges, and thereby confirming
our initially-reported absorption rate. Taking the ratio of the line profile
during transit to the unperturbed line profile, we also show that the spectral
signature of the absorption by the exoplanetary hydrogen nebula is symmetric
and typical of a Lorentzian, optically thick medium. Our results question the
adequacy of models that require a huge absorption and/or a strong asymmetry
between the blue and red side of the absorption line during transit as no such
features could be detected in the HST FUV absorption profile. Finally, we show
that standard atmospheric models of HD209458b provide a good fit to the
observed absorption profile during transit. Other hybrid models assuming a
standard model with a thin layer of superthermal hydrogen on top remain
possible.


title: A Holographic Dual of Bjorken Flow

abstract:
  We propose a consistent setup for a holographic dual of Bjorken flow of
strongly coupled large-Nc N=4 SYM-theory plasma. We employ
Eddington-Finkelstein type coordinates for the dual geometry, and we propose a
late-time expansion there. We construct the dual geometry order by order, and
we show that the transport coefficients are determined by the regularity of the
geometry. We also show that the dual geometry has an apparent horizon hence an
event horizon, which covers the singularity at the origin. We prove that the
dual geometry is regular at all orders under an appropriate choice of the
transport coefficients. Our model is a concrete well-defined example of
time-dependent AdS/CFT.


title: Multiple-Retrapping Process in High-$T_c$ Intrinsic Josephson Junctions

abstract:
  We report measurements of switching-current distribution (SWCD) from a
phase-diffusion branch to a quasiparticle-tunneling branch as a function of
temperature in a cuprate-based intrinsic Josephson junction. Contrary to the
thermal-activation model, the width of the SWCD increases with decreasing
temperature, down to 1.5 K. Based on the multiple-retrapping model, we
quantitatively demonstrate that the quality factor of the junction in the
phase-diffusion regime determines the observed temperature dependence of the
SWCD.


title: A New Glauber Theory based on Multiple Scattering Theory

abstract:
  Glauber theory for nucleus-nucleus scattering at high incident energies is
reformulated so as to become applicable also for the scattering at intermediate
energies. We test validity of the eikonal and adiabatic approximations used in
the formulation, and discuss the relation between the present theory and the
conventional Glauber calculations with either the empirical nucleon-nucleon
profile function or the modified one including the in-medium effect.


title: What drives mutual fund asset concentration?

abstract:
  Is the large influence that mutual funds assert on the U.S. financial system
spread across many funds, or is it is concentrated in only a few? We argue that
the dominant economic factor that determines this is market efficiency, which
dictates that fund performance is size independent and fund growth is
essentially random. The random process is characterized by entry, exit and
growth. We present a new time-dependent solution for the standard equations
used in the industrial organization literature and show that relaxation to the
steady-state solution is extremely slow. Thus, even if these processes were
stationary (which they are not), the steady-state solution, which is a very
heavy-tailed power law, is not relevant. The distribution is instead
well-approximated by a less heavy-tailed log-normal. We perform an empirical
analysis of the growth of mutual funds, propose a new, more accurate
size-dependent model, and show that it makes a good prediction of the
empirically observed size distribution. While mutual funds are in many respects
like other firms, market efficiency introduces effects that make their growth
process distinctly different. Our work shows that a simple model based on
market efficiency provides a good explanation of the concentration of assets,
suggesting that other effects, such as transaction costs or the behavioral
aspects of investor choice, play a smaller role.


title:
Problems of Star Formation Theory and Prospects of Submillimeter
  Observations

abstract:
  We consider current state of star formation theory and requirements to
observations in millimeter and submillimeter ranges which are necessary for
resolution of the most actual problems of the physics of star formation. Two
key features of star-forming regions which define observational requirements to
their studies, are relatively low energy of processes that take place there and
smallness of corresponding spatial scales. This is especially true for the
objects in the latest stages of ``pre-stellar'' evolution, that is, hot cores,
hyper- and ultracompact HII regions, and protoplanetary disks. Angular
resolution, sensitivity, and spectral coverage in existing projects of
ground-based and space telescopes of submillimeter and millimeter range are not
completely adequate to necessary requirements. To obtain detailed information
on star-forming regions as well as on individual protostars it is necessary to
employ a space-based interferometer.


title:
Reionization - A probe for the stellar population and the physics of the
  early universe

abstract:
  We calculate the reionization history for different models of the stellar
population and explore the effects of primordial magnetic fields, dark matter
decay and dark matter annihilation on reionization. We find that stellar
populations based on a Scalo-type initial mass function for Population II stars
can be ruled out as sole sources for reionization, unless star formation
efficiencies of more than 10% or very high photon escape fractions from the
parental halo are adopted. When considering primordial magnetic fields, we find
that the additional heat injection from ambipolar diffusion and decaying MHD
turbulence has significant impact on the thermal evolution and the ionization
history of the post-recombination universe and on structure formation. The
magnetic Jeans mass changes the typical mass scale of the star forming halos,
and depending on the adopted stellar model we derive upper limits to the
magnetic field strength between 0.7 and $5 $nG (comoving). For dark matter
annihilation, we find an upper limit to the thermally averaged mass-weighted
cross section of $10^{-33} \mathrm{cm}^3\mathrm{/s/eV}$. For dark matter decay,
our calculations yield a lower limit to the lifetime of dark matter particles
of $3\times10^{23}$ s. These limits are in agreement with constraints from
recombination and the X-ray background and provide an independent confirmation
at a much later epoch.


title: Quantum Convolutional Coding with Shared Entanglement: General Structure

abstract:
  We present a general theory of entanglement-assisted quantum convolutional
coding. The codes have a convolutional or memory structure, they assume that
the sender and receiver share noiseless entanglement prior to quantum
communication, and they are not restricted to possess the
Calderbank-Shor-Steane structure as in previous work. We provide two
significant advances for quantum convolutional coding theory. We first show how
to "expand" a given set of quantum convolutional generators. This expansion
step acts as a preprocessor for a polynomial symplectic Gram-Schmidt
orthogonalization procedure that simplifies the commutation relations of the
expanded generators to be the same as those of entangled Bell states (ebits)
and ancilla qubits. The above two steps produce a set of generators with
equivalent error-correcting properties to those of the original generators. We
then demonstrate how to perform online encoding and decoding for a stream of
information qubits, halves of ebits, and ancilla qubits. The upshot of our
theory is that the quantum code designer can engineer quantum convolutional
codes with desirable error-correcting properties without having to worry about
the commutation relations of these generators.


title: Wave-like Solutions for Bianchi type-I cosmologies in 5D

abstract:
  We derive exact solutions to the vacuum Einstein field equations in 5D, under
the assumption that (i) the line element in 5D possesses self-similar symmetry,
in the classical understanding of Sedov, Taub and Zeldovich, and that (ii) the
metric tensor is diagonal and independent of the coordinates for ordinary 3D
space. These assumptions lead to three different types of self-similarity in
5D: homothetic, conformal and "wave-like". In this work we present the most
general wave-like solutions to the 5D field equations. Using the standard
technique based on Campbell's theorem, they generate a large number of
anisotropic cosmological models of Bianchi type-I, which can be applied to our
universe after the big-bang, when anisotropies could have played an important
role. We present a complete review of all possible cases of self-similar
anisotropic cosmologies in 5D. Our analysis extends a number of previous
studies on wave-like solutions in 5D with spatial spherical symmetry.


title: Vector Currents of Massive Neutrinos of an Electroweak Nature

abstract:
  The mass of an electroweakly interacting neutrino consists of the electric
and weak parts responsible for the existence of its charge, charge radius, and
magnetic moment. Such connections explain the formation of paraneutrinos, for
example, at the polarized neutrino electroweak scattering by spinless nuclei.
We derive the structural equations that relate the self-components of mass to
charge, charge radius, and magnetic moment of each neutrino as a consequence of
unification of fermions of a definite flavor. They indicate the availability of
neutrino universality and require following its logic in a constancy law
dependence of the size implied from the multiplication of a weak mass of
neutrino by its electric mass. According to this principle, all Dirac neutrinos
of a vector nature, regardless of the difference in their masses, have the same
charge, an identical charge radius, as well as an equal magnetic moment.
Thereby, the possibility appears of establishing the laboratory limits of weak
masses of the investigated types of neutrinos. Finding estimates show clearly
that the earlier measured properties of these particles may testify in favor of
the unified mass structure of their interaction with any of the corresponding
types of gauge fields.


title: On the Rate of Channel Polarization

abstract:
  It is shown that for any binary-input discrete memoryless channel $W$ with
symmetric capacity $I(W)$ and any rate $R <I(W)$, the probability of block
decoding error for polar coding under successive cancellation decoding
satisfies $P_e \le 2^{-N^\beta}$ for any $\beta<\frac12$ when the block-length
$N$ is large enough.


title: Quintom Cosmology with General Potentials

abstract:
  We investigate the phase-space structure of the quintom paradigm in the
framework of a spatially flat, open, or closed isotropic and homogeneous
universe. We examine the dynamical evolution under the assumption of late-time
dark energy domination, without specifying the explicit quintom potential form.
The obtained cosmological behavior is qualitatively different than that
acquired from the single phantom model.


title: Neutrino Mass Hierarchies in a Mass Matrix Form Versus its Inverse Form

abstract:
  A neutrino mass matrix model M_\nu with M_\nu^T =M_\nu and a model with its
inverse matrix form \widetilde{M}_\nu = m_0^2 (M_\nu^*)^{-1} can be
diagonalized by the same mixing matrix U_\nu. It is investigated whether a
scenario which provides a matrix model M_\nu with normal mass hierarchy can
also give a model with an inverted mass hierarchy by considering a model with
an inverse form of M_\nu.


title: Pinwheel stabilization by ocular dominance segregation

abstract:
  We present an analytical approach for studying the coupled development of
ocular dominance and orientation preference columns. Using this approach we
demonstrate that ocular dominance segregation can induce the stabilization and
even the production of pinwheels by their crystallization in two types of
periodic lattices. Pinwheel crystallization depends on the overall dominance of
one eye over the other, a condition that is fulfilled during early cortical
development. Increasing the strength of inter-map coupling induces a transition
from pinwheel-free stripe solutions to intermediate and high pinwheel density
states.


title:
On derivation of Euler-Lagrange Equations for incompressible
  energy-minimizers

abstract:
  We prove that any distribution $q$ satisfying the equation $\nabla q=\div{\bf
f}$ for some tensor ${\bf f}=(f^i_j), f^i_j\in h^r(U)$ ($1\leq r<\infty$) -the
{\it local Hardy space}, $q$ is in $h^r$, and is locally represented by the sum
of singular integrals of $f^i_j$ with Calder\'on-Zygmund kernel. As a
consequence, we prove the existence and the local representation of the
hydrostatic pressure $p$ (modulo constant) associated with incompressible
elastic energy-minimizing deformation ${\bf u}$ satisfying $|\nabla {\bf u}|^2,
|{\rm cof}\nabla{\bf u}|^2\in h^1$. We also derive the system of Euler-Lagrange
equations for incompressible local minimizers ${\bf u}$ that are in the space
$K^{1,3}_{\rm loc}$; partially resolving a long standing problem. For H\"older
continuous pressure $p$, we obtain partial regularity of area-preserving
minimizers.


title: Entanglement-redistribution boxes

abstract:
  We establish a framework to study the classical-communication properties of
primitive local operations assisted by classical communication which realize
various redistributions of entanglement, like, e.g., entanglement swapping. On
the one hand, we analyze what local operations and how much classical
communication are needed to perform them. On the other hand, we investigate
whether and to what extent such primitives can help to establish classical
communication when they are used in the form of black boxes available to
spatially-separated users. In particular, we find that entanglement swapping
costs more communication than it can signal; in this sense, entanglement
swapping is a weaker primitive than quantum teleportation.


title:
Perturbation theory of computing QCD jet cross sections beyond NLO
  accuracy

abstract:
  We discuss the problems that arise when one wishes to extend the existing
general methods of computing radiative corrections to QCD jet cross sections to
beyond next-to-leading order. Then we present a subtraction scheme that can be
defined at any order in perturbation theory. We give a status report of the
implementation of the method to computing jet cross sections in
electron-positron annihilation at the next-to-next-to-leading order accuracy.


title: Non-Gaussianity in Island Cosmology

abstract:
  In this paper we fully calculate the non-Gaussianity of primordial curvature
perturbation of island universe by using the second order perturbation
equation. We find that for the spectral index $n_s\simeq 0.96$, which is
favored by current observations, the non-Gaussianity level $f_{NL}$ seen in
island will generally lie between 30 $\sim$ 60, which may be tested by the
coming observations. In the landscape, the island universe is one of
anthropically acceptable cosmological histories. Thus the results obtained in
some sense means the coming observations, especially the measurement of
non-Gaussianity, will be significant to make clear how our position in the
landscape is populated.


title:
Interdisciplinarity in Socio-economics, mathematical analysis and
  predictability of complex systems

abstract:
  In this essay, I attempt to provide supporting evidence as well as some
balance for the thesis on `Transforming socio-economics with a new
epistemology' presented by Hollingworth and Mueller (2008). First, I review a
personal highlight of my own scientific path that illustrates the power of
interdisciplinarity as well as unity of the mathematical description of natural
and social processes. I also argue against the claim that complex systems are
in general `not susceptible to mathematical analysis, but must be understood by
letting them evolve over time or with simulation analysis'. Moreover, I present
evidence of the limits of the claim that scientists working within Science II
do not make predictions about the future because it is too complex. I stress
the potentials for a third `Quantum Science' and its associated conceptual and
philosophical revolutions, and finally point out some limits of the `new'
theory of networks.


title: Small exotic Stein manifolds

abstract:
  It is known that the only Stein filling of the standard contact structure on
S^3 is B^4. In this paper, we construct simply connected exotic compact Stein
4-manifold pairs for any Betti number $b_2 \geq 1$; we do this by enlarging
corks and plugs.


title: Reflection principle and Ocone martingales

abstract:
  Let $M =(M_t)_{t\geq 0}$ be any continuous real-valued stochastic process. We
prove that if there exists a sequence $(a_n)_{n\geq 1}$ of real numbers which
converges to 0 and such that $M$ satisfies the reflection property at all
levels $a_n$ and $2a_n$ with $n\geq 1$, then $M$ is an Ocone local martingale
with respect to its natural filtration. We state the subsequent open question:
is this result still true when the property only holds at levels $a_n$? Then we
prove that the later question is equivalent to the fact that for Brownian
motion, the $\sigma$-field of the invariant events by all reflections at levels
$a_n$, $n\ge1$ is trivial. We establish similar results for skip free
$\mathbb{Z}$-valued processes and use them for the proof in continuous time,
via a discretisation in space.


title:
Rotational velocities of the giants in symbiotic stars: III. Evidence of
  fast rotation in S-type symbiotics

abstract:
  We have measured the projected rotational velocities (vsini) in a number of
symbiotic stars and M giants using high resolution spectroscopic observations.
On the basis of our measurements and data from the literature, we compare the
rotation of mass-donors in symbiotics with vsini of field giants and find that:
  (1) the K giants in S-type symbiotics rotate at vsini>4.5 km/s, which is 2-4
times faster than the field K giants;
  (2) the M giants in S-type symbiotics rotate on average 1.5 times faster than
the field M giants. Statistical tests show that these differences are highly
significant: p-value < 0.001 in the spectral type bins K2III-K5III,
M0III-M6III, and M2III-M5III;
  (3) our new observations of D'-type symbiotics also confirm that they are
fast rotators.
  As a result of the rapid rotation, the cool giants in symbiotics should have
3-30 times larger mass loss rates. Our results suggest also that bipolar
ejections in symbiotics seem to happen in objects where the mass donors rotate
faster than the orbital period.
  All spectra used in our series of papers can be obtained upon request from
the authors.


title: Comment on 'A neutrino's wobble?'

abstract:
  Comment on P. Walker, Nature 453 (2008) 864,
http://www.nature.com/nature/journal/v453/n7197/full/453864a.html


title:
Nonequilibrium Green's function method for phonon-phonon interaction and
  ballistic-diffusive thermal transport

abstract:
  Phonon-phonon interaction is systematically studied by nonequilibrium Green's
function (NEGF) formulism in momentum space at finite temperatures. Within the
quasi-particle approximation, phonon frequency shift and lifetime are obtained
from the retarded self-energy. The lowest order NEGF provides the same phonon
lifetime as Fermi's golden rule. Thermal conductance is predicted by the
Landauer formula with a phenomenological transmission function. The main
advantage of our method is that it covers both ballistic and diffusive limits
and thermal conductance of different system sizes can be easily obtained once
the mode-dependent phonon mean free path is calculated by NEGF. As an
illustration, the method is applied to two one-dimensional atom chain models
(the FPU-\beta model and the \phi^4 model) with an additional harmonic on-site
potential. The obtained thermal conductance is compared with that from a
quasi-classical molecular dynamics method. The harmonic on-site potential is
shown to remove the divergence of thermal conductivity in the FPU-\beta model.


title:
Absolute Dimensions and Apsidal Motion of the Eccentric Binary V731
  Cephei

abstract:
  A detailed analysis of new and existing photometric, spectroscopic and
spatial distribution data of the eccentric binary V731 Cep was performed.
Spectroscopic orbital elements of the system were obtained by means of
cross-correlation technique. According to the solution of radial velocities
with UBVRcIc light curves, V731 Cep consists of two main-sequence stars with
masses M$_{1}$=2.577 (0.098) M$_{\odot}$, M$_{2}$=2.017 (0.084) M$_{\odot}$,
radii R$_{1}$=1.823 (0.030) R$_{\odot}$, R$_{2}$=1.717 (0.025) R$_{\odot}$, and
temperatures T$_{eff1}$=10700 (200) K, T$_{eff2}$=9265 (220) K separated from
each other by a=23.27 (0.29) R$_{\odot}$ in an orbit with inclination of
88$^{\circ}$.70 (0.03). Analysis of the O--C residuals yielded a rather long
apsidal motion period of U=10000(2500) yr compared to the observational history
of the system. The relativistic contribution to the observed rates of apsidal
motion for V731 Cep is significant (76%). The combination of the absolute
dimensions and the apsidal motion properties of the system yielded consistent
observed internal structure parameter (log$\bar{k}_{2,obs}$=-2.36) compared to
the theory (log$\bar{k}_{2,theo}$=-2.32). Evolutionary investigation of the
binary by two methods (Bayesian and evolutionary tracks) shows that the system
is t=133(26) Myr old and has a metallicity of [M/H]=-0.04(0.02) dex. The
similarities in the spatial distribution and evolutionary properties of V731
Cep with the nearby ($\rho\sim3^{\circ}$.9) open cluster NGC 7762 suggests that
V731 Cep could have been evaporated from NGC 7762.


title:
The SIDE dual VIS-NIR fiber fed spectrograph for the 10.4 m Gran
  Telescopio Canarias

abstract:
  SIDE (Super Ifu Deployable Experiment) is proposed as second-generation,
common-user instrument for the GTC. It will be a low and intermediate
resolution fiber fed spectrograph, highly efficient in multi-object and 3D
spectroscopy. The low resolution part (R = 1500, 4000) is called Dual VIS-NIR
because it will observe in the VIS and NIR bands (0.4 ~V 1.7 microns)
simultaneously. Because of the large number of fibers, a set of ~10 identical
spectrographs is needed, each with a mirror collimator, a dichroic and two
refractive cameras. The cameras are optimized for 0.4 - 0.95 microns (VIS) and
0.95 - 1.7 microns (NIR) respectively.


title:
Effects of Macroion Geometry and Charge Discretization in Charge
  Reversal

abstract:
  The effects of discrete macroion surface charge distribution and valences of
these surface charges and counterions on charge reversal have been studied for
macroions of three different geometries and compared with those of continuous
surface charge distributions. The geometry of the macroion has been observed to
play an important role in overcharging in these cases. The interplay of
valences of discrete microions and counterions have noticeable effects on
overcharging efficiency. For some valence combinations overcharging the
macroion with discrete surface charge is seen to be more efficient than those
with continuous charge distribution. The calculations have been performed using
a previously developed energy minimization simulation technique. For comparison
purposes the corresponding continuous charge distribution cases together with
an analytical model derived from modified Scatchard approach (for continuous
charge distribution) have been evaluated.


title: Phase diagram of a generalized Winfree model

abstract:
  We study the phase diagram of a generalized Winfree model. The modification
is such that the coupling depends on the fraction of synchronized oscillators,
a situation which has been noted in some experiments on coupled Josephson
junctions and mechanical systems. We let the global coupling k be a function of
the Kuramoto order parameter r through an exponent z such that z=1 corresponds
to the standard Winfree model, z<1 strengthens the coupling at low r (low
amount of synchronization) and, at z>1, the coupling is weakened for low r.
Using both analytical and numerical approaches, we find that z controls the
size of the incoherent phase region, and one may make the incoherent behavior
less typical by choosing z<1. We also find that the original Winfree model is a
rather special case, indeed the partial locked behavior disappears for z>1. At
fixed k and varying gamma, the stability boundary of the locked phase
corresponds to a transition that is continuous for z<1 and first-order for z>1.
This change in the nature of the transition is in accordance with a previous
study on a similarly modified Kuramoto model.


title:
Displacement-noise-free gravitational-wave detection with two
  Fabry-Perot cavities

abstract:
  We propose two detuned Fabry-Perot cavities, each pumped through both the
mirrors, positioned in line as a toy model of the gravitational-wave (GW)
detector free from displacement noise of the test masses. It is demonstrated
that the noise of cavity mirrors can be completely excluded in a proper linear
combination of the cavities output signals. This model is illustrated by a
simplified round trip model (without Fabry-Perot cavities). We show that in
low-frequency region the obtained displacement-noise-free response signal is
stronger than the one of the interferometer recently proposed by S.Kawamura and
Y.Chen.


title:
Generalized Conformal Symmetry and Recovery of SO(8) in Multiple M2 and
  D2 Branes

abstract:
  We investigate conformal symmetries of the Aharony-Bergman-Jafferis-Maldacena
(ABJM) theory for multiple M2 branes and the Lorentzian
Bagger-Lambert-Gustavsson (L-BLG) theory which can be obtained by taking a
scaling limit k (>>N) -> \infty of the ABJM theory. The conformal symmetry is
maintained in the L-BLG by considering general space-time varying solutions to
the constraint equations. The dual geometry is reduced to d=10 AdS4 x CP3 in
the scaling limit and has the same conformal symmetry. The curvature radius R
satisfies l_{11p} << l_{10p} << R << l_s (l_{dp} and l_s are the d-dimensional
Planck lengths and the string scale), and the theory is in a region where an
\alpha' expansion is not valid. We also study how the SO(8) covariance is
recovered in the AdS4 x CP3 geometry by taking the scaling limit.


title: QCD Contributions to the Froissart bound for the total cross-section

abstract:
  We discuss the effect of infrared soft gluons on the asymptotic behaviour of
the total cross-section. We use a singular but integrable expression for the
strong coupling constant in the infrared limit and relate its behaviour to the
satisfaction of the Froissart bound, giving a specific phenomenological
example.


title: Hopf images and inner faithful representations

abstract:
  We develop a general theory of Hopf image of a Hopf algebra representation,
with the associated concept of inner faithful representation, modelled on the
notion of faithful representation of a discrete group. We study several
examples, including group algebras, enveloping algebras of Lie algebras,
pointed Hopf algebras, function algebras, twistings and cotwistings, and we
present a Tannaka duality formulation of the notion of Hopf image.


title:
Hypocenter interval statistics between successive earthquakes in the
  two-dimensional Burridge-Knopoff model

abstract:
  We study statistical properties of spatial distances between successive
earthquakes, the so-called hypocenter intervals, produced by a two-dimensional
(2D) Burridge-Knopoff model involving stick-slip behavior. It is found that
cumulative distributions of hypocenter intervals can be described by the
$q$-exponential distributions with $q<1$, which is also observed in nature. The
statistics depend on a friction and stiffness parameters characterizing the
model and a threshold of magnitude. The conjecture which states that $q_t+q_r
\sim 2$, where $q_t$ and $q_r$ are an entropy index of time intervals and
spatial intervals, respectively, can be reproduced semi-quantitatively. It is
concluded that we provide a new perspective on the Burridge-Knopoff model which
addresses that the model can be recognized as a realistic one in view of the
reproduction of the spatio-temporal interval statistics of earthquakes on the
basis of nonextensive statistical mechanics.


title: The SDSS-UKIDSS Fundamental Plane of Early-type Galaxies

abstract:
  We derive the Fundamental Plane (FP) relation for a sample of 1430 early-type
galaxies in the optical (r band) and the near-infrared (K band), by combining
SDSS and UKIDSS data. With such a large, homogeneous dataset, we are able to
assess the dependence of the FP on the waveband. Our analysis indicates that
the FP of luminous early-type galaxies is essentially waveband independent,
with its coefficients increasing at most by 8% from the optical to the NIR.
This finding fits well into a consistent picture where the tilt of the FP is
not driven by stellar populations, but results from other effects, such as
non-homology. In this framework, the optical and NIR FPs require more massive
galaxies to be slightly more metal rich than less massive ones, and to have
highly synchronized ages, with an age variation per decade in mass smaller than
a few percent.


title: Borel resummation of transverse momentum distributions

abstract:
  We present a new prescription for the resummation of contributions due to
soft gluon emission to the trasverse momentum distribution of processes such as
Drell-Yan production in hadronic collisions. We show that familiar difficulties
in obtaining resummed results as a function of transverse momentum starting
from impact-parameter space resummation are related to the divergence of the
perturbative expansion of the momentum-space result. We construct a resummed
expression by Borel resummation of this divergent series, removing the
divergence in the Borel inversion through the inclusion of a suitable higher
twist term. The ensuing resummation prescription is free of numerical
instabilities, is stable upon the inclusion of subleading terms, and the
original divergent perturbative series is asymptotic to it. We compare our
results to those obtained using alternative prescriptions, and discuss the
ambiguities related to the resummation procedure.


title: The Galactic Disk-Halo transition - Evidence from Stellar Abundances

abstract:
  New information on the relations between the Galactic disks, the halo, and
satellite galaxies is being obtained from elemental abundances of stars having
metallicities in the range -1.5 < [Fe/H] < -0.5. The first results for a sample
of 26 halo stars and 13 thick-disk stars observed with the ESO VLT/UVES
spectrograph are presented. The halo stars fall in two distinct groups: One
group (9 stars) has [alpha/Fe]= 0.30 +-0.03 like the thick-disk stars. The
other group (17 stars) shows a clearly deviating trend ranging from [alpha/Fe]=
0.20 at [Fe/H]= -1.3 to [alpha/Fe]= 0.08 at [Fe/H]= -0.8. The kinematics of the
stars are discussed and the abundance ratios Na/Fe, Ni/Fe, Cu/Fe and Ba/Y are
applied to see if the low-alpha stars are connected to the thin disk or to
Milky Way satellite galaxies. Furthermore, we compare our data with simulations
of chemical abundance distributions in hierarchically formed stellar halos in a
LambdaCDM Universe.