title:
The C/O ratio at low metallicity: constraints on early chemical
  evolution from observations of Galactic halo stars

abstract:
  We present new measurements of the abundances of carbon and oxygen derived
from high-excitation C I and O I absorption lines in metal-poor halo stars,
with the aim of clarifying the main sources of these two elements in the early
stages of the chemical enrichment of the Galaxy. We target 15 new stars
compared to our previous study, with an emphasis on additional C/O
determinations in the crucial metallicity range -3<[Fe/H]<-2. Departures from
local thermodynamic equilibrium were accounted for in the line formation for
both carbon and oxygen. The non-LTE effects are very strong at the lowest
metallicities but, contrary to what has sometimes been assumed in the past due
to a simplified assessment, of different degrees for the two elements. In
addition, for the 28 stars with [Fe/H]<-1 previously analysed, stellar
parameters were re-derived and non-LTE corrections applied in the same fashion
as for the rest of our sample, giving consistent abundances for 43 halo stars
in total. The new observations and non-LTE calculations strengthen previous
suggestions of an upturn in C/O towards lower metallicity (particularly for
[O/H]<-2). Adopting the H collisional cross-sections estimated from the
classical Drawin formula leads to [C/O]~0 at [O/H]~-3. To remove the upturn in
C/O, near-LTE formation for O I lines would be required, which could only
happen if the H collisional efficiency with the Drawin recipe is underestimated
by factors of up to several tens of times, which we consider unlikely. The high
C/O values derived at the lowest metallicities may be revealing the
fingerprints of Population III stars or may signal rotationally-aided
nucleosynthesis in more normal Population II stars.


title: Which group velocity of light in a dispersive medium?

abstract:
  The interaction between a light pulse, traveling in air, and a generic
linear, non-absorbing and dispersive structure is analyzed. It is shown that
energy conservation imposes a constraint between the group velocities of the
transmitted and reflected light pulses. It follows that the two fields
propagate with group velocities depending on the dispersive properties of the
environment (air) and on the transmission properties of the optical structure,
and are one faster and the other slower than the incident field. In other
words, the group velocity of a light pulse in a dispersive medium is
reminiscent of previous interactions. One example is discussed in detail.


title:
All-sky LIGO Search for Periodic Gravitational Waves in the Early S5
  Data

abstract:
  We report on an all-sky search with the LIGO detectors for periodic
gravitational waves in the frequency range 50--1100 Hz and with the frequency's
time derivative in the range -5.0E-9 Hz/s to zero. Data from the first eight
months of the fifth LIGO science run (S5) have been used in this search, which
is based on a semi-coherent method (PowerFlux) of summing strain power.
Observing no evidence of periodic gravitational radiation, we report 95%
confidence-level upper limits on radiation emitted by any unknown isolated
rotating neutron stars within the search range. Strain limits below 1.E-24 are
obtained over a 200-Hz band, and the sensitivity improvement over previous
searches increases the spatial volume sampled by an average factor of about 100
over the entire search band. For a neutron star with nominal equatorial
ellipticity of 1.0E-6, the search is sensitive to distances as great as 500
pc--a range that could encompass many undiscovered neutron stars, albeit only a
tiny fraction of which would likely be rotating fast enough to be accessible to
LIGO. This ellipticity is at the upper range thought to be sustainable by
conventional neutron stars and well below the maximum sustainable by a strange
quark star.


title: Prospects for the Detection of the Deep Solar Meridional Circulation

abstract:
  We perform helioseismic holography to assess the noise in p-mode travel-time
shifts which would form the basis of inferences of large-scale flows throughout
the solar convection zone. We also derive the expected travel times from a
parameterized return (equatorward) flow component of the meridional circulation
at the base of the convection zone from forward models under the assumption of
the ray and Born approximations. From estimates of the signal-to-noise ratio
for measurements focused near the base of the convection zone, we conclude that
the helioseismic detection of the deep meridional flow including the return
component may not be possible using data spanning an interval less than a solar
cycle.


title:
Matching the Bare and MSbar Charm Quark Masses Using Weak Coupling
  Simulations

abstract:
  We provide a new determination of the charm quark mass using the Highly
Improved Staggered Quark (HISQ) action, finding m_c(3 GeV) = 0.983(23) GeV. Our
determination makes extensive use of second order lattice perturbation theory
in matching the bare lattice mass to the MSbar scheme. This matching utilises
both traditional diagrammatic perturbation theory and weak coupling
simulations. The second of these techniques allows us to extract perturbative
coefficients from Monte-Carlo simulations and the process of doing this is laid
out in some detail here.


title: STIS Imaging of the HR 4796A Circumstellar Debris Ring

abstract:
  We have obtained high spatial resolution imaging observations of the HR 4796A
circumstellar debris dust ring using the broad optical response of the Hubble
Space Telescope Imaging Spectrograph in coronagraphic mode. We use our visual
wavelength observations to improve upon the earlier measured geometrical
parameters of the ring-like disk. Two significant flux density asymmetries are
noted: (1) preferential forward scattering by the disk grains and (2) an
azimuthal surface brightness anisotropy about the morphological minor axis of
the disk with corresponding differential ansal brightness. We find the debris
ring offset from the location of the star by ~1.4 AU, a shift insufficient to
explain the differing brightnesses of the NE and SW ansae simply by the 1/$r^2$
dimmunition of starlight. The STIS data also better quantify the radial
confinement of the starlight-scattering circumstellar debris, to a
characteristic region <14 AU in photometric half-width, with a significantly
steeper inner truncation than outward falloff in radial surface brightness. The
inferred spatial distribution of the disk grains is consistent with the
possibility of one or more unseen co-orbital planetary-mass perturbers, and the
colors of the disk grains are consistent with a collisionally evolved
population of debris, possibly including ices reddened by radiation exposure to
the central star.


title:
Pressure effects on the electron-doped high Tc superconductor
  BaFe(2-x)Co(x)As(2)

abstract:
  Application of pressures or electron-doping through Co substitution into Fe
sites transforms the itinerant antiferromagnet BaFe(2)As(2) into a
superconductor with the Tc exceeding 20K. We carried out systematic transport
measurements of BaFe(2-x)Co(x)As(2) superconductors in pressures up to 2.5GPa,
and elucidate the interplay between the effects of electron-doping and
pressures. For the underdoped sample with nominal composition x = 0.08,
application of pressure strongly suppresses a magnetic instability while
enhancing Tc by nearly a factor of two from 11K to 21K. In contrast, the
optimally doped x=0.20 sample shows very little enhancement of Tc=22K under
applied pressure. Our results strongly suggest that the proximity to a magnetic
instability is the key to the mechanism of superconductivity in iron-pnictides.


title: Saturn Forms by Core Accretion in 3.4 Myr

abstract:
  We present two new in situ core accretion simulations of Saturn with planet
formation timescales of 3.37 Myr (model S0) and 3.48 Myr (model S1), consistent
with observed protostellar disk lifetimes. In model S0, we assume rapid grain
settling reduces opacity due to grains from full interstellar values (Podolak
2003). In model S1, we do not invoke grain settling, instead assigning full
interstellar opacities to grains in the envelope. Surprisingly, the two models
produce nearly identical formation timescales and core/atmosphere mass ratios.
We therefore observe a new manifestation of core accretion theory: at large
heliocentric distances, the solid core growth rate (limited by Keplerian
orbital velocity) controls the planet formation timescale. We argue that this
paradigm should apply to Uranus and Neptune as well.


title:
Correlation between microstructure and magnetotransport in organic
  semiconductor spin valve structures

abstract:
  We have studied magnetotransport in organic-inorganic hybrid multilayer
junctions. In these devices, the organic semiconductor (OSC) Alq$_3$
(tris(8-hydroxyquinoline) aluminum) formed a spacer layer between ferromagnetic
(FM) Co and Fe layers. The thickness of the Alq$_3$ layer was in the range of
50-150 nm. Positive magnetoresistance (MR) was observed at 4.2 K in a current
perpendicular to plane geometry, and these effects persisted up to room
temperature. The devices' microstructure was studied by X-ray reflectometry,
Auger electron spectroscopy and polarized neutron reflectometry (PNR). The
films show well-defined layers with modest average chemical roughness (3-5 nm)
at the interface between the Alq$_3$ and the surrounding FM layers.
Reflectometry shows that larger MR effects are associated with smaller
FM/Alq$_3$ interface width (both chemical and magnetic) and a magnetically dead
layer at the Alq$_3$/Fe interface. The PNR data also show that the Co layer,
which was deposited on top of the Alq$_3$, adopts a multi-domain magnetic
structure at low field and a perfect anti-parallel state is not obtained. The
origins of the observed MR are discussed and attributed to spin coherent
transport. A lower bound for the spin diffusion length in Alq$_3$ was estimated
as $43 \pm 5$ nm at 80 K. However, the subtle correlations between
microstructure and magnetotransport indicate the importance of interfacial
effects in these systems.


title: Calculating Quark Number Susceptibilities with Domain-Wall Fermions

abstract:
  We present results from calculations of different quark number and hadronic
susceptibilities on 2+1-flavor dynamical domain wall ensembles. We find that
the iso-spin and electric charge susceptibilities are especially well suited to
determine the transition temperature, as these quantities show only small
statistical errors. Moreover, the transition values of the coupling obtained
from iso-spin and electrical charge susceptibilities are in good agreement with
the one obtained from the chiral condensate.


title: DMTPC: a new apparatus for directional detection of Dark Matter

abstract:
  Directional detection of Dark Matter allows for unambiguous direct detection
of WIMPs as well as discrimination between various Dark Matter models in our
galaxy. The DMTPC detector is a low-pressure TPC with optical readout designed
for directional direct detection of WIMPs. By using CF4 gas as the active
material, the detector also has excellent sensitivity to spin-dependent
interactions of Dark Matter on protons.


title:
Spectroscopic evidence for preformed Cooper pairs in the pseudogap phase
  of cuprates

abstract:
  Angle-resolved photoemission on underdoped La$_{1.895}$Sr$_{0.105}$CuO$_4$
reveals that in the pseudogap phase, the dispersion has two branches located
above and below the Fermi level with a minimum at the Fermi momentum. This is
characteristic of the Bogoliubov dispersion in the superconducting state. We
also observe that the superconducting and pseudogaps have the same d-wave form
with the same amplitude. Our observations provide direct evidence for preformed
Cooper pairs, implying that the pseudogap phase is a precursor to
superconductivity.


title: Meson decay in a corrected $3^P_0$ model

abstract:
  Extensively applied to both light and heavy meson decay and standing as one
of the most successful strong decay models is the $3^P_0$ model, in which
$q\bar{q}$ pair production is the dominant mechanism. The pair production can
be obtained from the non-relativistic limit of a microscopic interaction
Hamiltonian involving Dirac quark fields. The evaluation of the decay amplitude
can be performed by a diagrammatic technique for drawing quark lines. In this
paper we use an alternative approach which consists in a mapping technique, the
Fock-Tani formalism, in order to obtain an effective Hamiltonian starting from
same microscopic interaction. An additional effect is manifest in this
formalism associated to the extended nature of mesons: bound-state corrections.
A corrected $3^P_0$ is obtained and applied, as an example, to
$b_{1}\to\omega\pi$ and $a_{1}\to\rho\pi$ decays.


title: VERITAS Blazar Observations - Recent Results

abstract:
  We present the discovery of very high energy (VHE) gamma-ray emission from
the high-frequency-peaked BL Lac object 1ES 0806+524 (z=0.138) and the
intermediate-frequency-peaked BL Lac object W Comae (z=0.102) with VERITAS. VHE
emission was discovered from these objects during the 2007/2008 observing
campaign, with a strong outburst from W Comae detected in mid-March, lasting a
few days. Quasi-simultaneous spectral energy distributions are presented,
incorporating optical (AAVSO), and X-ray (Swift/RXTE) observations. We also
present the energy spectrum of the distant BL Lac (z=0.182) 1ES 1218+304 which
was detected by VERITAS during the 2006/2007 observing campaign. The energy
spectrum is discussed in the context of different models of absorption from the
diffuse extragalactic background radiation. We present multiwavelength
observations of the blazar Markarian 421 (z=0.03), including a strong flare
initially detected by the Whipple 10m gamma-ray telescope. Finally we present a
broadband spectral energy distribution for 1ES 2344+514 (z=0.044) which is
successfully fit using a one zone synchrotron self-Compton model.


title: Affine and toric hyperplane arrangements

abstract:
  We extend the Billera-Ehrenborg-Readdy map between the intersection lattice
and face lattice of a central hyperplane arrangement to affine and toric
hyperplane arrangements. For arrangements on the torus, we also generalize
Zaslavsky's fundamental results on the number of regions.


title: A model for the evolutionary diversification of religions

abstract:
  We address the problem of diversification in religions by studying selection
on cultural memes that colonize humans hosts. In analogy to studying the
evolution of pathogens or symbionts colonizing animal hosts, we use models for
host-pathogen dynamics known from theoretical epidemiology. In these models,
religious memes colonize individual humans. Rates of transmission of memes
between humans, i.e., transmission of cultural content, and rates of loss of
memes (loss of faith) are determined by the phenotype of the cultural memes,
and by interactions between hosts carrying different memes. In particular,
based on the notion that religion can lead to oppression of lower classes once
a religious society has reached a certain size, we assume that the rate of loss
increases as the number of humans colonized by a particular meme phenotype
increases. This generates frequency-dependent selection on cultural memes, and
we use evolutionary theory to show that this frequency dependence can generate
the emergence of coexisting clusters of different meme types. The different
clusters correspond to different religions, and hence our model describes the
emergence of distinct descendent religions from single ancestral religions.

categories: physics.soc-ph cond-mat.other nlin.AO q-bio.PE


title: First-order action and Euclidean quantum gravity

abstract:
  We show that the on-shell path integral for asymptotically flat Euclidean
spacetimes can be given in the first-order formulation of general relativity,
without assuming the boundary to be isometrically embedded in Euclidean space
and without adding infinite counter-terms. For illustrative examples of our
approach, we evaluate the first-order action for the four-dimensional Euclidean
Schwarzschild and NUT-charged spacetimes to derive the corresponding on-shell
partition functions, and show that the correct thermodynamic quantities for the
solutions are reproduced.


title: Families of IIB duals for nonrelativistic CFTs

abstract:
  We show that the recent string theory embedding of a spacetime with
nonrelativistic Schrodinger symmetry can be generalised to a twenty one
dimensional family of solutions with that symmetry. Our solutions include IIB
backgrounds with no three form flux turned on, and arise as near horizon limits
of branewave spacetimes. We show that there is a hypersurface in the space of
these theories where an instability appears in the gravitational description,
indicating a phase transition in the nonrelativistic field theory dual. We also
present simple embeddings of duals for nonrelativistic critical points where
the dynamical critical exponent can take many values z \neq 2.


title:
Simulating hydromagnetic processes in star formation: introducing
  ambipolar diffusion into an adaptive mesh refinement code

abstract:
  Given the importance of simulating hydromagnetic processes that impact star
formation, we have earlier developed a 3D adaptive mesh approach that allows us
to include hydromagnetic processes during the formation and evolution of cores,
discs, and stars in observed regions of star formation. In this paper, we take
the next step in this program - namely - to develop a modified version of the
3D adaptive mesh refinement (AMR) code FLASH in which the ambipolar diffusion
of the magnetic field in poorly ionized molecular gas is implemented. We
approach the problem using a single-fluid approximation to simplify numerical
calculations. In this paper, we present a series of test cases including
oblique isothermal and non--isothermal C-shocks. We also present a study of the
quasi-static collapse of an initial uniform, self-gravitating, magnetized
sphere that is initially supported by its magnetic field against collapse (i.e.
magnetically subcritical). Applications to the collapse of a pre-stellar
Bonnor-Ebert sphere are presented in a companion paper.


title: Wilson twisted mass fermions in the epsilon regime

abstract:
  In this proceeding contribution we report on the ongoing effort to understand
and simulate Wilson twisted mass fermions in the so called epsilon regime.


title: VERITAS Observations of the BL Lac Object 1ES 1218+304

abstract:
  The VERITAS collaboration reports the detection of very-high-energy (VHE)
gamma-ray emission from the high-frequency-peaked BL Lac object 1ES 1218+304
located at a redshift of z=0.182. A gamma-ray signal was detected with high
statistical significance for the observations taken during several months in
the 2006-2007 observing season. The photon spectrum between ~160 GeV and ~1.8
TeV is well described by a power law with an index of Gamma = 3.08 +/-
0.34(stat) +/- 0.2(sys). The integral flux above 200 GeV corresponds to ~6% of
that of the Crab Nebula. The light curve does not show any evidence for VHE
flux variability. Using lower limits on the density of the extragalactic
background light (EBL) in the near-IR to mid-IR we are able to limit the range
of intrinsic energy spectra for 1ES 1218+304. We show that the intrinsic photon
spectrum is harder than a power law with an index of Gamma = 2.32 +/- 0.37.
When including constraints from the spectra of 1ES 1101-232 and 1ES 0229+200,
the spectrum of 1ES 1218+304 is likely to be harder than Gamma = 1.86 +/- 0.37.


title: VERITAS Observations of the Coma Cluster of Galaxies

abstract:
  Clusters of galaxies are one of the few prominent classes of objects
predicted to emit gamma rays not yet detected by satellites like EGRET or
ground-based Imaging Atmospheric Cherenkov Telescopes (IACTs). The detection of
Very High Energy (VHE, E > 100 GeV) gamma rays from galaxy clusters would
provide insight into the morphology of non-thermal particles and fields in
clusters. VERITAS, an array of four 12-meter diameter IACTs, is ideally
situated to observe the massive Coma cluster, one of the best cluster
candidates in the Northern Hemisphere. This contribution details the results of
VERITAS observations of the Coma cluster of galaxies during the 2007-2008
observing season.


title:
Constraining a matter-dominated cosmological model with bulk viscosity
  proportional to the Hubble parameter

abstract:
  We present and constrain a cosmological model where the only component is a
pressureless fluid with bulk viscosity as an explanation for the present
accelerated expansion of the universe. We study the particular model of a bulk
viscosity coefficient proportional to the Hubble parameter. The model is
constrained using the SNe Ia Gold 2006 sample, the Cosmic Microwave Background
(CMB) shift parameter R, the Baryon Acoustic Oscillation (BAO) peak A and the
Second Law of Thermodynamics (SLT). It was found that this model is in
agreement with the SLT using only the SNe Ia test. However when the model is
constrained using the three cosmological tests together (SNe+CMB+BAO) we found:
1.- The model violates the SLT, 2.- It predicts a value of H_0 \approx 53 km
sec^{-1} Mpc^{-1} for the Hubble constant, and 3.- We obtain a bad fit to data
with a \chi^2_{min} \approx 532. These results indicate that this model is
viable just if the bulk viscosity is triggered in recent times.


title: Stability of holonomicity over quasi-projective varieties

abstract:
  Let $\V$ be a mixed characteristic complete discrete valuation ring with
perfect residue field $k$. We solve Berthelot's conjectures on the stability of
the holonomicity over smooth projective formal $\V$-schemes. Then we build a
category of complexes of arithmetic $\D$-modules over quasi-projective
$k$-varieties with bounded, $F$-holonomic cohomology. We get its stability
under Grothendieck's six operations.


title: NMR measurements of intrinsic spin susceptibility in LaFeAsO(0.9)F(0.1)

abstract:
  We will probe the intrinsic behavior of spin susceptibility chi_(spin) in the
LaFeAsO(1-x)F(x) superconductor (x ~ 0.1, Tc ~ 27K) using 19-F and 75-As NMR
techniques. Our new results firmly establish the pseudo-gap behavior with
Delta_(PG)/kB ~ 140K. The estimated magnitude of chi_(spin) at 290K,
~1.8x10^(-4) [emu/mol-Fe], is approximately twice larger than that in high Tc
cuprates. We also show that chi_(spin) levels off below ~50K down to Tc.


title:
Lorentz-violating contributions of the Carroll-Field-Jackiw model to the
  CMB anisotropy

abstract:
  We study the finite temperature properties of the
Maxwell-Carroll-Field-Jackiw (MCFJ) electrodynamics for a purely spacelike
background. Starting from the associated finite temperature partition function,
a modified black body spectral distribution is obtained. We thus show that, if
the CMB radiation is described by this model, the spectrum presents an
anisotropic angular energy density distribution. We show, at leading order,
that the Lorentz-breaking contributions for the Planck's radiation law and for
the Stefan-Boltzmann's law are nonlinear in frequency and quadratic in
temperature, respectively. Using our results, we set up bounds for the
Lorentz-breaking parameter, and show that Lorentz violation in the context of
the MCFJ model is unable to yield the known CMB anisotropy (of 1 part in
$10^{5})$.


title:
Quantum switching at a mean-field instability of a Bose-Einstein
  condensate in an optical lattice

abstract:
  It is shown that bifurcations of the mean-field dynamics of a Bose-Einstein
condensate can be related with the quantum phase transitions of the original
many-body system. As an example we explore the intra-band tunneling in the
two-dimensional optical lattice. Such a system allows for easy control by the
lattice depth as well as for macroscopic visualization of the phase transition.
The system manifests switching between two selftrapping states or from a
selftrapping state to a superposition of the macroscopically populated
selftrapping states with the step-like variation of the control parameter about
the bifurcation point. We have also observed the magnification of the
microscopic difference between the even and odd number of atoms to a
macroscopically distinguishable dynamics of the system.

categories: cond-mat.other cond-mat.mes-hall nlin.CD quant-ph


title:
Clathration of Volatiles in the Solar Nebula and Implications for the
  Origin of Titan's atmosphere

abstract:
  We describe a scenario of Titan's formation matching the constraints imposed
by its current atmospheric composition. Assuming that the abundances of all
elements, including oxygen, are solar in the outer nebula, we show that the icy
planetesimals were agglomerated in the feeding zone of Saturn from a mixture of
clathrates with multiple guest species, so-called stochiometric hydrates such
as ammonia hydrate, and pure condensates. We also use a statistical
thermodynamic approach to constrain the composition of multiple guest
clathrates formed in the solar nebula. We then infer that krypton and xenon,
that are expected to condense in the 20-30 K temperature range in the solar
nebula, are trapped in clathrates at higher temperatures than 50 K. Once
formed, these ices either were accreted by Saturn or remained embedded in its
surrounding subnebula until they found their way into the regular satellites
growing around Saturn. In order to explain the carbon monoxide and primordial
argon deficiencies of Titan's atmosphere, we suggest that the satellite was
formed from icy planetesimals initially produced in the solar nebula and that
were partially devolatilized at a temperature not exceeding 50 K during their
migration within Saturn's subnebula. The observed deficiencies of Titan's
atmosphere in krypton and xenon could result from other processes that may have
occurred both prior or after the completion of Titan. Thus, krypton and xenon
may have been sequestrated in the form of XH3+ complexes in the solar nebula
gas phase, causing the formation of noble gas-poor planetesimals ultimately
accreted by Titan. Alternatively, krypton and xenon may have also been trapped
efficiently in clathrates located on the satellite's surface or in its
atmospheric haze.


title:
Considerations about the Aharonov-Anandan Phase for Time Independent
  Hamiltonians

abstract:
  We present a method for calculating the Aharonov-Anandan phase for
time-independent Hamiltonians that avoids the calculation of evolution
operators. We compare the generic method used to calculate the Aharonov-Anandan
phase with the method proposed here through four examples; a spin-1/2 particle
in a constant magnetic field, an arbitrary infinite-sized Hamiltonian with two
known eigenvalues, a Fabry-Perot cavity with one movable mirror and a three
mirrors cavity with a slightly transmissive movable middle mirror.


title:
On representable graphs, semi-transitive orientations, and the
  representation numbers

abstract:
  A graph $G=(V,E)$ is representable if there exists a word $W$ over the
alphabet $V$ such that letters $x$ and $y$ alternate in $W$ if and only if
$(x,y)\in E$ for each $x\neq y$. If $W$ is $k$-uniform (each letter of $W$
occurs exactly $k$ times in it) then $G$ is called $k$-representable. It was
shown that a graph is representable if and only if it is $k$-representable for
some $k$. Minimum $k$ for which a representable graph $G$ is $k$-representable
is called its representation number.
  In this paper we give a characterization of representable graphs in terms of
orientations. Namely, we show that a graph is representable if and only if it
admits an orientation into a so-called \emph{semi-transitive digraph}. This
allows us to prove a number of results about representable graphs, not the
least that 3-colorable graphs are representable. We also prove that the
representation number of a graph on $n$ nodes is at most $n$, from which one
concludes that the recognition problem for representable graphs is in NP. This
bound is tight up to a constant factor, as we present a graph whose
representation number is $n/2$.
  We also answer several questions, in particular, on representability of the
Petersen graph and local permutation representability.


title: Vertex decomposable graphs and obstructions to shellability

abstract:
  Inspired by several recent papers on the edge ideal of a graph G, we study
the equivalent notion of the independence complex of G. Using the tool of
vertex decomposability from geometric combinatorics, we show that 5-chordal
graphs with no chordless 4-cycles are shellable and sequentially
Cohen-Macaulay. We use this result to characterize the obstructions to
shellability in flag complexes, extending work of Billera, Myers, and Wachs. We
also show how vertex decomposability may be used to show that certain graph
constructions preserve shellability.


title: On the relationship between continuous- and discrete-time quantum walk

abstract:
  Quantum walk is one of the main tools for quantum algorithms. Defined by
analogy to classical random walk, a quantum walk is a time-homogeneous quantum
process on a graph. Both random and quantum walks can be defined either in
continuous or discrete time. But whereas a continuous-time random walk can be
obtained as the limit of a sequence of discrete-time random walks, the two
types of quantum walk appear fundamentally different, owing to the need for
extra degrees of freedom in the discrete-time case.
  In this article, I describe a precise correspondence between continuous- and
discrete-time quantum walks on arbitrary graphs. Using this correspondence, I
show that continuous-time quantum walk can be obtained as an appropriate limit
of discrete-time quantum walks. The correspondence also leads to a new
technique for simulating Hamiltonian dynamics, giving efficient simulations
even in cases where the Hamiltonian is not sparse. The complexity of the
simulation is linear in the total evolution time, an improvement over
simulations based on high-order approximations of the Lie product formula. As
applications, I describe a continuous-time quantum walk algorithm for element
distinctness and show how to optimally simulate continuous-time query
algorithms of a certain form in the conventional quantum query model. Finally,
I discuss limitations of the method for simulating Hamiltonians with negative
matrix elements, and present two problems that motivate attempting to
circumvent these limitations.


title:
Decrease of Entropy, Quantum Statistics and Possible Violation of Pauli
  Exclusion Principle

abstract:
  We propose that a necessary condition of decrease of entropy in isolated
system is existence of internal interactions. Then a theoretical development
and some possible examples on decrease of entropy are researched. In quantum
region, in particular for some Bose systems, decrease of entropy is more
possible. The base of violation of Pauli exclusion principle is unified quantum
statistics and attractive interactions, which corresponds also to decrease of
entropy with internal interactions. Perhaps, some basis principles have
essential relations.


title: Galactic Nonlinear Dynamic Model

abstract:
  We develop a model for spiral galaxies based on a nonlinear realization of
the Newtonian dynamics starting from the momentum and mass conservations in the
phase space. The radial solution exhibits a rotation curve in qualitative
accordance with the observational data.


title: Recent Searches for Exotic Physics at the BaBar/PEP-II B-factory

abstract:
  I present three recent results from searches for exotic physics at the
BaBar/PEP-II B-factory. These results span many of the samples produced at the
B-factory, including B mesons, tau leptons, and Upsilon(3S) mesons. We have
searched for CPT-violation in B mixing and find no significant deviation from
the no-violation hypothesis. We have also searched for lepton-flavor-violating
decays of the tau using tau- -> omega l- and tau- -> l+ l- l+ and their charge
conjugates. We find no evidence for these processes and set upper limits on
their branching fractions. Finally, we have searched for a low-mass Higgs boson
in the decay Upsilon(3S) -> gamma A0, where the Higgs decays invisibly. We find
no evidence for such a decay and set upper limits across a range of possible
Higgs masses.


title:
Detection of source inhomogeneity through event-by-event two-pion
  Bose-Einstein correlations

abstract:
  We develop a method for detecting the inhomogeneity of the pion-emitting
sources produced in ultra-relativistic heavy ion collisions, through
event-by-event two-pion Bose-Einstein correlations. The root-mean-square of the
error-inverse-weighted fluctuations between the two-pion correlation functions
of single and mixed events are useful observables for the detection. By
investigating the root-mean-square of the weighted fluctuations for different
impact parameter regions people may hopefully determine the inhomogeneity of
the particle-emitting in the coming Large Hadron Collider (LHC) heavy ion
experiments.


title: Iron Emission Lines on the Galactic Ridge Observed with Suzaku

abstract:
  In order to elucidate origin of the Galactic Ridge X-ray Emission, we
analyzed Suzaku data taken at various regions along the Galactic plane and
studied their Fe-K emission line features. Suzaku resolved the Fe line complex
into three narrow lines at ~6.4 keV,~6.7 keV and ~6.97 keV, which are K-lines
from neutral (or low-ionized), He-like, and H-like iron ions, respectively. The
6.7 keV line is clearly seen in all the observed regions and its longitudinal
distribution is consistent with that determined from previous observations. The
6.4 keV emission line was also found in various Galactic plane regions (b~0).
Differences in flux ratios of the 6.4 keV/6.7 keV and 6.97 keV/6.7 keV lines
between the Galactic plane and the Galactic center regions are studied and its
implication is discussed.


title:
On boundedness, existence and uniqueness of strong solutions of the
  Navier-Stokes Equations in 3 dimensions

abstract:
  In this paper we consider the Navier-Stokes Equations in 3 dimensions in the
vorticity formulation in the absence of the external forces. We derive upper
bounds on L_{infinity} norm of omega and use them together with the Local
Existence and Uniqueness results to show Global Existence and Uniqueness of the
solution provided that at t=0, L_{infinity} norm of omega is finite, or L_4
norm of omega is finite.


title: Spectral properties of a tractable collective Hamiltonian

abstract:
  The spectral properties of a tractable collective model Hamiltonian are
studied. The potential energy is truncated up to quartic terms in the
quadrupole deformation variables, incorporating vibrational,
$\gamma$-independent rotational and axially deformed rotational structures.
These physically significant limits are analysed in detail and confronted with
well-established approximation schemes. Furthermore, transitional Hamiltonians
in between the limits are presented and discussed. All results are obtained
within a recently presented Cartan-Weyl based framework to calculate
$SU(1,1)\times SO(5)$ embedded quadrupole collective observables.


title:
Elastic and total reaction cross sections of oxygen isotopes in Glauber
  theory

abstract:
  We systematically calculate the total reaction cross sections of oxygen
isotopes, $^{15-24}$O, on a $^{12}$C target at high energies using the Glauber
theory. The oxygen isotopes are described with Slater determinants generated
from a phenomenological mean-field potential. The agreement between theory and
experiment is generally good, but a sharp increase of the reaction cross
sections from ^{21}O to ^{23}O remains unresolved. To examine the sensitivity
of the diffraction pattern of elastic scattering to the nuclear surface, we
study the differential elastic-scattering cross sections of proton-^{20,21,23}O
at the incident energy of 300 MeV by calculating the full Glauber amplitude.


title:
A high resolution view of the jet termination shock in a hot spot of the
  nearby radio galaxy Pictor A: implications for X-ray models of radio galaxy
  hot spots

abstract:
  Images made with the VLBA have resolved the region in a nearby radio galaxy,
Pictor A, where the relativistic jet that originates at the nucleus terminates
in an interaction with the intergalactic medium, a so-called radio galaxy hot
spot. This image provides the highest spatial resolution view of such an object
to date (16 pc), more than three times better than previous VLBI observations
of similar objects. The north-west Pictor A hot spot is resolved into a complex
set of compact components, seen to coincide with the bright part of the hot
spot imaged at arcsecond-scale resolution with the VLA. In addition to a
comparison with VLA data, we compare our VLBA results with data from the HST
and Chandra telescopes, as well as new Spitzer data. The presence of pc-scale
components in the hot spot, identifying regions containing strong shocks in the
fluid flow, leads us to explore the suggestion that they represent sites of
synchrotron X-ray production, contributing to the integrated X-ray flux of the
hot spot, along with X-rays from synchrotron self-Compton scattering. This
scenario provides a natural explanation for the radio morphology of the hot
spot and its integrated X-ray emission, leading to very different predictions
for the higher energy X-ray spectrum compared to previous studies. From the
sizes of the individual pc-scale components and their angular spread, we
estimate that the jet width at the hot spot is in the range 70 - 700 pc, which
is comparable to similar estimates in PKS 2153-69, 3C 205, and 4C 41.17. The
lower limit in this range arises from the suggestion that the jet may dither in
its direction as it passes through hot spot backflow material close to the jet
termination point, creating a "dentist drill" effect on the inside of a cavity
700 pc in diameter.


title:
Non-negative mixed finite element formulations for a tensorial diffusion
  equation

abstract:
  We consider the tensorial diffusion equation, and address the discrete
maximum-minimum principle of mixed finite element formulations. In particular,
we address non-negative solutions (which is a special case of the
maximum-minimum principle) of mixed finite element formulations. The discrete
maximum-minimum principle is the discrete version of the maximum-minimum
principle.
  In this paper we present two non-negative mixed finite element formulations
for tensorial diffusion equations based on constrained optimization techniques
(in particular, quadratic programming). These proposed mixed formulations
produce non-negative numerical solutions on arbitrary meshes for low-order
(i.e., linear, bilinear and trilinear) finite elements. The first formulation
is based on the Raviart-Thomas spaces, and is obtained by adding a non-negative
constraint to the variational statement of the Raviart-Thomas formulation. The
second non-negative formulation based on the variational multiscale
formulation.
  For the former formulation we comment on the affect of adding the
non-negative constraint on the local mass balance property of the
Raviart-Thomas formulation. We also study the performance of the active set
strategy for solving the resulting constrained optimization problems. The
overall performance of the proposed formulation is illustrated on three
canonical test problems.


title: How to measure redshift-space distortions without sample variance

abstract:
  We show how to use multiple tracers of large-scale density with different
biases to measure the redshift-space distortion parameter
beta=f/b=(dlnD/dlna)/b (where D is the growth rate and a the expansion factor),
to a much better precision than one could achieve with a single tracer, to an
arbitrary precision in the low noise limit. In combination with the power
spectrum of the tracers this allows a much more precise measurement of the
bias-free velocity divergence power spectrum, f^2 P_m - in fact, in the low
noise limit f^2 P_m can be measured as well as would be possible if velocity
divergence was observed directly, with rms improvement factor ~[5.2(beta^2+2
beta+2)/beta^2]^0.5 (e.g., ~10 times better than a single tracer for beta=0.4).
This would allow a high precision determination of f D as a function of
redshift with an error as low as 0.1%. We find up to two orders of magnitude
improvement in Figure of Merit for the Dark Energy equation of state relative
to Stage II, a factor of several better than other proposed Stage IV Dark
Energy surveys. The ratio b_2/b_1 will be determined with an even greater
precision than beta, producing, when measured as a function of scale, an
exquisitely sensitive probe of the onset of non-linear bias. We also extend in
more detail previous work on the use of the same technique to measure
non-Gaussianity. Currently planned redshift surveys are typically designed with
signal to noise of unity on scales of interest, and are not optimized for this
technique. Our results suggest that this strategy may need to be revisited as
there are large gains to be achieved from surveys with higher number densities
of galaxies.


title: Smooth varieties up to A^1-homotopy and algebraic h-cobordisms

abstract:
  We start to study the problem of classifying smooth proper varieties over a
field k from the standpoint of A^1-homotopy theory. Motivated by the
topological theory of surgery, we discuss the problem of classifying up to
isomorphism all smooth proper varieties having a specified A^1-homotopy type.
Arithmetic considerations involving the sheaf of A^1-connected components lead
us to introduce several different notions of connectedness in A^1-homotopy
theory. We provide concrete links between these notions, connectedness of
points by chains of affine lines, and various rationality properties of
algebraic varieties (e.g., rational connectedness).
  We introduce the notion of an A^1-h-cobordism, an algebro-geometric analog of
the topological notion of h-cobordism, and use it as a tool to produce
non-trivial A^1-weak equivalences of smooth proper varieties. Also, we give
explicit computations of refined A^1-homotopy invariants, such as the
A^1-fundamental sheaf of groups, for some A^1-connected varieties. We observe
that the A^1-fundamental sheaf of groups plays a central yet mysterious role in
the structure of A^1-h-cobordisms. As a consequence of these observations, we
completely solve the classification problem for rational smooth proper surfaces
over an algebraically closed field: while there exist arbitrary dimensional
moduli of such surfaces, there are only countably many A^1-homotopy types, each
uniquely determined by the isomorphism class of its A^1-fundamental sheaf of
groups.


title: On Banach Spaces containing $l_p$ or $c_0$

abstract:
  We use the Gowers block Ramsey theorem to characterize Banach spaces
containing isomorphs of $\ell_p$ (for some $1 \leq p < \infty$) or $c_0$.


title: Collision Resolution by Exploiting Symbol Misalignment

abstract:
  This paper presents CRESM, a novel collision resolution method for decoding
collided packets in random-access wireless networks. In a collision,
overlapping signals from several sources are received simultaneously at a
receiver. CRESM exploits symbol misalignment among the overlapping signals to
recover the individual packets. CRESM can be adopted in 802.11 networks without
modification of the transmitter design; only a simple DSP technique is needed
at the receiver to decode the overlapping signals. Our simulations indicate
that CRESM has better BER performance than the simplistic Successive
Interference Cancellation (SIC) technique that treats interference as noise,
for almost all SNR regimes. The implication of CRESM for random-access
networking is significant: in general, using CRESM to resolve collisions of up
to n packets, network throughput can be boosted by more than n times if the
transmitters are allowed to transmit more aggressively in the MAC protocol.


title: Wavelength-Multiplexed Entanglement Distribution over 10 km of Fiber

abstract:
  We report the first experimental demonstration of wavelength-multiplexed
entanglement distribution. 44 channels of highly-entangled photon-pairs from
one single broadband source are distributed over 10 km of fiber.


title: Efficient Defence against Misbehaving TCP Receiver DoS Attacks

abstract:
  The congestion control algorithm of TCP relies on correct feedback from the
receiver to determine the rate at which packets should be sent into the
network. Hence, correct receiver feedback (in the form of TCP acknowledgements)
is essential to the goal of sharing the scarce bandwidth resources fairly and
avoiding congestion collapse in the Internet. However, the assumption that a
TCP receiver can always be trusted (to generate feedback correctly) no longer
holds as there are plenty of incentives for a receiver to deviate from the
protocol. In fact, it has been shown that a misbehaving receiver (whose aim is
to bring about congestion collapse) can easily generate acknowledgements to
conceal packet loss, so as to drive a number of honest, innocent senders
arbitrarily fast to create a significant number of non-responsive packet flows,
leading to denial of service to other Internet users. We give the first formal
treatment to this problem. We also give an efficient, provably secure mechanism
to force a receiver to generate feedback correctly; any incorrect
acknowledgement will be detected at the sender and cheating TCP receivers would
be identified. The idea is as follows: for each packet sent, the sender
generates a tag using a secret key (known to himself only); the receiver could
generate a proof using the packet and the tag alone, and send it to the sender;
the sender can then verify the proof using the secret key; an incorrect proof
would indicate a cheating receiver. The scheme is very efficient in the sense
that the TCP sender does not need to store the packet or the tag, and the
proofs for multiple packets can be aggregated at the receiver. The scheme is
based on an aggregate authenticator. In addition, the proposed solution can be
applied to network-layer rate-limiting architectures requiring correct
feedback.


title:
Large-N phase transitions in the spectrum of products of complex
  matrices

abstract:
  It is shown that the simplest multiplicative random complex matrix model
generalizes the large-N phase structure found in the unitary case: A
perturbative regime is joined to a nonperturbative regime at a point of
nonanalyticity.


title:
Improved Seed Methods for Symmetric Positive Definite Linear Equations
  with Multiple Right-hand Sides

abstract:
  We consider symmetric positive definite systems of linear equations with
multiple right-hand sides. The seed conjugate gradient method solves one
right-hand side with the conjugate gradient method and simultaneously projects
over the Krylov subspace thus developed for the other right-hand sides. Then
the next system is solved and used to seed the remaining ones. Rounding error
in the conjugate gradient method limits how much the seeding can improve
convergence. We propose three changes to the seed conjugate gradient method:
only the first right-hand side is used for seeding, this system is solved past
convergence, and the roundoff error is controlled with some
reorthogonalization. We will show that results are actually better with only
one seeding, even in the case of related right-hand sides. Controlling rounding
error gives the potential for rapid convergence for the second and subsequent
right-hand sides.


title:
Comment on "Electron screening and excitonic condensation in
  double-layer graphene systems"

abstract:
  The influence of screening on the condensed state of bilayer graphene is
studied within the framework of the Thomas Fermi approximation. We find that
screening has little effect on the Kosterlitz-Thouless temperature in the
strongly interacting regime. Furthermore, we predict that the phase transition
to the condensed state is first order.


title: Enhanced Integrated Scoring for Cleaning Dirty Texts

abstract:
  An increasing number of approaches for ontology engineering from text are
gearing towards the use of online sources such as company intranet and the
World Wide Web. Despite such rise, not much work can be found in aspects of
preprocessing and cleaning dirty texts from online sources. This paper presents
an enhancement of an Integrated Scoring for Spelling error correction,
Abbreviation expansion and Case restoration (ISSAC). ISSAC is implemented as
part of a text preprocessing phase in an ontology engineering system. New
evaluations performed on the enhanced ISSAC using 700 chat records reveal an
improved accuracy of 98% as compared to 96.5% and 71% based on the use of only
basic ISSAC and of Aspell, respectively.


title:
Effect of many-body quantum fluctuations on matrix Berry phases of a
  two-dimensional n-type semiconductor quantum dot

abstract:
  In the presence of spin-orbit coupling and inversion symmetry of the lateral
confinement potential a single electron does not exhibit matrix Berry phases in
quasi-two-dimensional semiconductor quantum dots. In such a system we
investigate whether many-body correlation effects can lead to finite matrix
Berry phases. We find that the transformation properties of many-electron
wavefunctions under two-dimensional inversion operation do not allow finite
matrix Berry phases. This effect is exact and is independent of the form of
electron-electron interactions. On the other hand, quasi-two-dimensional
semiconductor quantum dots with lateral confinement potential without inversion
symmetry can have finite matrix Berry phases. We find that many-body quantum
fluctuations can change matrix Berry phases significantly in such systems.


title:
High-statistics study of neutral-pion pair production in two-photon
  collisions

abstract:
  The differential cross section for the process $\gamma \gamma \to \pi^0
\pi^0$ has been measured in the kinematic range 0.6 GeV $< W < 4.1$ GeV, $|\cos
\theta^*|<0.8$ in energy and pion scattering angle, respectively, in the
$\gamma\gamma$ center-of-mass system. The results are based on a 223 fb$^{-1}$
data sample collected with the Belle detector at the KEKB $e^+ e^-$ collider.
Using the data with $W > 1.4$ GeV, we obtain results on light-quark resonances
and charmonia. We also compare the observed angular dependence and ratios of
cross sections for neutral-pair and charged-pair production to QCD models.
Differential cross sections are fitted in the energy region, $1.4 \GeV < W <
2.2 \GeV$, with a simple model where partial waves consist of resonances such
as $f_2'(1525)$, $f_2(1950)$ and $f_4(2050)$ and smooth backgrounds. In the
higher energy region, we observe production of the $\chi_{c0}$ charmonium state
and obtain the product of its two-photon decay width and the branching fraction
to $\pi^0\pi^0$. The energy and angular dependences above 3.1 GeV are
compatible with those measured in the $\pi^+\pi^-$ channel, and in addition we
find that the cross section ratio, $\sigma(\pi^0\pi^0)/\sigma(\pi^+\pi^-)$, is
$0.32 \pm 0.03 \pm 0.05$ on average in the 3.1-4.1 GeV region.


title:
Measurement of the Differential Branching Fraction and Forward-Backward
  Asymmetry for B->K(*)l+l-

abstract:
  We study B->K(*)l+l- decays based on a large data sample of 657 million BB
pairs collected with the Belle detector at the KEKB e+e- collider. The
differential branching fraction, the isospin asymmetry, the K* polarization,
and the forward-backward asymmetry (A_FB) as functions of q^2 are reported. The
fitted A_FB spectrum tends to be shifted toward the positive side from the SM
expectation. The measured branching fractions and lepton flavor ratios
(electron/muon) are B(B->K*l+l-)=(10.8+1.1-1.0+-0.9)*10^-7,
B(B->Kl+l-)=(4.8+0.5-0.4+-0.3)*10^-7, R_K*=1.21+-0.25+-0.08, and
R_K=0.97+-0.18+-0.06, respectively.


title: Efficient photon sorter in a high-dimensional Hilbert space

abstract:
  An increase in the dimension of state space for quantum key distribution
(QKD) can decrease its fidelity requirements while also increasing its
bandwidth. A significant obstacle for QKD with qudits (d>2) has been an
efficient and practical quantum state sorter for photons whose complex fields
are modulated in both amplitude and phase. We propose such a sorter based on a
multiplexed thick hologram, constructed e.g. from photo-thermal refractive
(PTR) glass. We validate this approach using coupled-mode theory with
parameters consistent with PTR glass to simulate a holographic sorter. The
model assumes a three-dimensional state space spanned by three tilted
planewaves. The utility of such a sorter for broader quantum information
processing applications can be substantial.


title:
Derivation of the fundamental equations of continuum thermodynamics from
  statistical mechanics

abstract:
  Assuming a classical statistical system of point particles the fundamental
equations of continuum thermomechanics (continuity equation, equation of
motion, and energy equation) shall be derived exactly. The macroscopic state
functions (density, velocity, stress, energy density, heat flux) are
interpreted as expected values.


title: An equivariant index formula for almost-CR manifolds

abstract:
  We consider a consider the case of a compact manifold M, together with the
following data: the action of a compact Lie group H and a smooth H-invariant
distribution E, such that the H-orbits are transverse to E. These data
determine a natural equivariant differential form with generalized coefficients
J(E,X) whose properties we describe.
  When E is equipped with a complex structure, we define a class of symbol
mappings in terms of the resulting almost-CR structure that are H-transversally
elliptic whenever the action of H is transverse to E. We determine a formula
for the H-equivariant index of such symbols that involves only J(E,X) and
standard equivariant characteristic classes. This formula generalizes the
formula given in arXiv:0712.2431 for the case of a contact manifold.


title:
Quasiclassical calculations of BBR-induced depopulation rates and
  effective lifetimes of Rydberg nS, nP and nD alkali-metal atoms with n < 80

abstract:
  Rates of depopulation by blackbody radiation (BBR) and effective lifetimes of
alkali-metal \textit{nS}, \textit{n}P and \textit{nD} Rydberg states have been
calculated in a wide range of principal quantum numbers $n \le 80$ at the
ambient temperatures of 77, 300 and 600 K. Quasiclassical formulas were used to
calculate the radial matrix elements of the dipole transitions from Rydberg
states. Good agreement of our numerical results with the available theoretical
and experimental data has been found. We have also obtained simple analytical
formulas for estimates of effective lifetimes and BBR-induced depopulation
rates, which well agree with the numerical data.


title:
Exactly solvable pairing model for superconductors with a p+ip-wave
  symmetry

abstract:
  We present the exact Bethe ansatz solution for the two-dimensional BCS
pairing Hamiltonian with p_x + i p_y symmetry. Using both mean-field theory and
the exact solution we obtain the ground-state phase diagram parameterized by
the filling fraction and the coupling constant. It consists of three phases
denoted weak coupling BCS, weak pairing, and strong pairing. The first two
phases are separated by a topologically protected line where the exact ground
state is given by the Moore-Read pfaffian state. In the thermodynamic limit the
ground-state energy is discontinuous on this line. The other two phases are
separated by the critical line, also topologically protected, previously found
by Read and Green. We establish a duality relation between the weak and strong
pairing phases, whereby ground states of the weak phase are "dressed" versions
of the ground states of the strong phase by zero energy (Moore-Read) pairs and
characterized by a topological order parameter.

categories: cond-mat.supr-con hep-th nucl-th quant-ph


title:
Multi-Conjugate Adaptive Optics VLT imaging of the distant old open
  cluster FSR1415

abstract:
  We employ the recently installed near infrared Multi-Conjugate Adaptive
optics demonstrator (MAD) to determine basic properties of a newly identified,
old and distant, Galactic open cluster (FSR1415). The MAD facility remarkably
approaches the diffraction limit, reaching a resolution of 0.07 arcsec (in K),
that is also uniform in a field of ~1.8 arcmin in diameter.
  The MAD facility provides photometry that is 50% complete at K~19. This
corresponds to about ~2.5 mag below the cluster main sequence turn-off. This
high quality data set allows us to derive an accurate heliocentric distance of
~8.6 kpc, a metallicity close to solar, and an age of ~2.5 Gyr. On the other
hand, the deepness of the data allow us to reconstruct (completeness-corrected)
mass functions indicating a relatively massive cluster, with a flat core MF.
The VLT/MAD capabilities will therefore provide fundamental data in
identifying/analyzing other faint and distant open clusters in the Galaxy III
and IV quadrants.


title: A chain complex and Quadrilaterals for normal surfaces

abstract:
  We interpret a normal surface in a (singular) three-manifold in terms of the
homology of a chain complex. This allows us to study the relation between
normal surfaces and their quadrilateral co-ordinates. Specifically, we give a
proof of an (unpublished) observation independently given by Casson and
Rubinstein saying that quadrilaterals determine a normal surface up to vertex
linking spheres. We also characterise the quadrilateral coordinates that
correspond to a normal surface in a (possibly ideal) triangulation.


title:
Novel critical exponent of magnetization curves near the ferromagnetic
  quantum phase transitions of Sr1-xAxRuO3 (A = Ca, La0.5Na0.5, and La)

abstract:
  We report a novel critical exponent delta=3/2 of magnetization curves
M=H^{1/delta} near the ferromagnetic quantum phase transitions of Sr1-xAxRuO3
(A = Ca, La0.5Na0.5, and La), which the mean field theory of the
Ginzburg-Landau-Wilson type fails to reproduce. The effect of dirty
ferromagnetic spin fluctuations might be a key.


title: Undergraduate Lecture Notes in Topological Quantum Field Theory

abstract:
  These third-year lecture notes are designed for a 1-semester course in
topological quantum field theory (TQFT). Assumed background in mathematics and
physics are only standard second-year subjects: multivariable calculus,
introduction to quantum mechanics and basic electromagnetism.
  Keywords: quantum mechanics/field theory, path integral, Hodge decomposition,
Chern-Simons and Yang-Mills gauge theories, conformal field theory


title: Non-cyclic graph associated with a group

abstract:
  We associate a graph $\mathcal{C}_G$ to a non locally cyclic group $G$
(called the non-cyclic graph of $G$) as follows: take $G\backslash Cyc(G)$ as
vertex set, where $Cyc(G)=\{x\in G | < x,y> \text{is cyclic for all} y\in G\}$
is called the cyclicizer of $G$, and join two vertices if they do not generate
a cyclic subgroup.
  For a simple graph $\Gamma$, $w(\Gamma)$ denotes the clique number of
$\Gamma$, which is the maximum size (if it exists) of a complete subgraph of
$\Gamma$. In this paper we characterize groups whose non-cyclic graphs have
clique numbers at most 4. We prove that a non-cyclic group $G$ is solvable
whenever $w(\mathcal{C}_G)<31$ and the equality for a non-solvable group $G$
holds if and only if $G/Cyc(G)\cong A_5$ or $S_5$.


title: Eight-dimensional Ricci-flat space related with the KP equation

abstract:
  Eight-dimensional the Ricci-flat space defined by solutions of the
Kadomtsev-Petviashvili equatin is presented. Its properties are discussed


title: Interacting multi-class transmissions in large stochastic networks

abstract:
  The mean-field limit of a Markovian model describing the interaction of
several classes of permanent connections in a network is analyzed. Each of the
connections has a self-adaptive behavior in that its transmission rate along
its route depends on the level of congestion of the nodes of the route. Since
several classes of connections going through the nodes of the network are
considered, an original mean-field result in a multi-class context is
established. It is shown that, as the number of connections goes to infinity,
the behavior of the different classes of connections can be represented by the
solution of an unusual nonlinear stochastic differential equation depending not
only on the sample paths of the process, but also on its distribution.
Existence and uniqueness results for the solutions of these equations are
derived. Properties of their invariant distributions are investigated and it is
shown that, under some natural assumptions, they are determined by the
solutions of a fixed-point equation in a finite-dimensional space.


title:
H2 Energetics in Galaxy-wide Shocks: Insights in Starburst Triggering
  and Galaxy Formation

abstract:
  Spitzer space telescope observations led to the surprising detection of a
diverse set of extragalactic sources whose infrared spectra are dominated by
line emission of molecular hydrogen (H2). The absence or relative weakness of
typical signs of star formation (like dust features, lines of ionized gas)
suggest the presence of large quantities of H2 gas with no (or very little)
associated star formation. We use the Stephan's Quintet (SQ) galaxy collision
to define a physical framework to describe the H2 formation and emission in
galaxy-wide shocks. SQ observations show that exceptionally turbulent H2 gas is
coexisting with a hot, X-ray emitting plasma. The extreme mid-IR H2 emission
from the shock exceeds that of the X-rays. These observations set a new light
on the contribution of H2 to the cooling of the interstellar medium, on the
relation between molecular gas and star formation, and on the energetics of
galaxy formation.
  These observations can be interpreted by considering that the shock is moving
through an inhomogeneous medium. They suggest that most of the shock energy is
transferred to bulk kinetic energy of the H2 gas. The turbulent energy of the
post-shock gas drives a mass cycle across the different gas phases where H2 is
forming out of the hot/warm gas. This interpretation puts the H2 emission into
a broader context including optical and X-ray observations. We propose that the
turbulence in the clouds is powered by a slow energy and momentum transfer from
the bulk motion of the gas and that the dissipation of this turbulent energy in
turn is powering the H2 emission.


title:
The R.I. Pimenov unified gravitation and electromagnetism field theory
  as semi-Riemannian geometry

abstract:
  More then forty years ago R.I. Pimenov introduced a new geometry --
semi-Riemannian one -- as a set of geometrical objects consistent with a
fibering $ pr: M_n \to M_m.$ He suggested the heuristic principle according to
which the physically different quantities (meter, second, coulomb etc.) are
geometrically modelled as space coordinates that are not superposed by
automorphisms. As there is only one type of coordinates in Riemannian geometry
and only three types of coordinates in pseudo-Riemannian one, a multiple
fibered semi-Riemannian geometry is the most appropriate one for the treatment
of more then three different physical quantities as unified geometrical field
theory.
  Semi-Euclidean geometry $^{3}R_5^4$ with 1-dimensional fiber $x^5$ and
4-dimensional Minkowski space-time as a base is naturally interpreted as
classical electrodynamics. Semi-Riemannian geometry $^{3}V_5^4$ with the
general relativity pseudo-Riemannian space-time $^{3}V^4,$ and 1-dimensional
fiber $x^5,$ responsible for the electromagnetism, provides the unified field
theory of gravitation and electromagnetism. Unlike Kaluza-Klein theories, where
the 5-th coordinate appears in nondegenerate Riemannian or pseudo-Riemannian
geometry, the theory based on semi-Riemannian geometry is free from defects of
the former. In particular, scalar field does not arise.
  PACS: 04.50.Cd, 02.40.-k, 11.10.Kk


title: Carrier doping to pseudo-low-dimensional compound La2RuO5

abstract:
  Hole carrier doping has been tried to pseudo-low-dimensional material La2RuO5
by substituting La3+ with Cd2+. Single phased samples of La2-xCdxRuO5 with x up
to 0.5 have been successfully obtained and also high pressure O2 annealing has
been performed to the x=0.5 sample. Although the formal ionic state of Ru is
expected to increase from 4+ (at x=0) to 4.5+ (at x=0.5), the magnetic and
electrical properties show no significant changes in as-sintered samples. In
contrast, high pressure O2 annealed x=0.5 samples show a little reduction of
electrical resistivity and the decrease of thermoelectric power at 260 K. From
these results, it can be speculated that the doped carriers are mostly
compensated by oxygen deficiency in as-sintered samples.


title:
SU(2) and SU(3) chiral perturbation theory analyses on meson and baryon
  masses in 2+1 flavor lattice QCD

abstract:
  We investigate the quark mass dependence of meson and baryon masses obtained
from 2+1 flavor dynamical quark simulations performed by the PACS-CS
Collaboration. With the use of SU(2) and SU(3) chiral perturbation theories up
to NLO, we examine the chiral behavior of the pseudoscalar meson masses and the
decay constants in terms of the degenerate up-down quark mass ranging form 3
MeV to 24 MeV and two choices of the strange quark mass around the physical
value. We discuss the convergence of the SU(2) and SU(3) chiral expansions and
present the results for the low energy constants. We find that the SU(3)
expansion is not convergent at NLO for the physical strange quark mass. The
chiral behavior of the nucleon mass is also discussed based on the SU(2) heavy
baryon chiral perturbation theory up to NNLO. Our results show that the
expansion is well behaved only up to m_pi^2 ~ 0.2 GeV^2.


title: Finitely presented algebras and groups defined by permutation relations

abstract:
  The class of finitely presented algebras over a field $K$ with a set of
generators $a_{1},..., a_{n}$ and defined by homogeneous relations of the form
$a_{1}a_{2}... a_{n} =a_{\sigma (a)} a_{\sigma (2)} ... a_{\sigma (n)}$, where
$\sigma$ runs through a subset $H$ of the symmetric group $\Sym_{n}$ of degree
$n$, is introduced. The emphasis is on the case of a cyclic subgroup $H$ of
$\Sym_{n}$ of order $n$. A normal form of elements of the algebra is obtained.
It is shown that the underlying monoid, defined by the same (monoid)
presentation, has a group of fractions and this group is described. Properties
of the algebra are derived. In particular, it follows that the algebra is a
semiprimitive domain. Problems concerning the groups and algebras defined by
arbitrary subgroups $H$ of $\Sym_{n}$ are proposed.


title:
Solving the two-center nuclear shell-model problem with
  arbitrarily-orientated deformed potentials

abstract:
  A general new technique to solve the two-center problem with
arbitrarily-orientated deformed realistic potentials is demonstrated, which is
based on the powerful potential separable expansion method. As an example,
molecular single-particle spectra for $^{12}$C + $^{12}$C $\to$ $^{24}$Mg are
calculated using deformed Woods-Saxon potentials. These clearly show that
non-axial symmetric configurations play a crucial role in molecular resonances
observed in reaction processes for this system at low energy.


title: Arithmetic infinite Grassmannians and the induced central extensions

abstract:
  The construction of families of Sato Grassmannians, their determinant line
bundles and the extensions induced by them are given. The base scheme is an
arbitrary scheme.


title:
Comparative study of the rovibrational properties of heteronuclear
  alkali dimers in electric fields

abstract:
  A comparative study of the effect of a static homogeneous electric field on
the rovibrational spectra of several polar dimers in their
$\textrm{X}^1\Sigma^+$ electronic ground state is performed. Focusing upon the
rotational ground state within each vibrational band, results for energies and
various expectation values are presented. For moderate field strengths the
electric field-induced energy shifts, orientation, alignment, and angular
motion hybridization are analyzed up to high vibrational excitations close to
the dissociation threshold.


title: Dissipative quantum dynamics in low-energy collisions of complex nuclei

abstract:
  Model calculations that include the effects of irreversible, environmental
couplings on top of a coupled-channels dynamical description of the collision
of two complex nuclei are presented. The Liouville-von Neumann equation for the
time-evolution of the density matrix of a dissipative system is solved
numerically providing a consistent transition from coherent to decoherent (and
dissipative) dynamics during the collision. Quantum decoherence and dissipation
are clearly manifested in the model calculations. Energy dissipation, due to
the irreversible decay of giant-dipole vibrational states of the colliding
nuclei, is shown to result in a hindrance of quantum tunneling and fusion.


title: Orientations of very faint galaxies in the Coma cluster

abstract:
  We have then searched for preferential orientations of faint galaxies in the
Coma cluster (down I_Vega~-11.5). By applying a deconvolution method to deep u*
and I band images of the Coma cluster, we were able to recover orientations
down to faint magnitudes. No preferential orientations are found in more than
95% of the cluster, and the brighter the galaxies, the fewer preferential
orientations. The minor axes of late type galaxies are radially oriented along
a northeast -southwest direction and are oriented north-south in the western
X-ray sub- structures. For early type galaxies, in the western regions showing
significant preferential orientations, galaxy major axes are oriented
perpendicularly to the north-south direction. In the eastern significant region
and close to NGC 4889, galaxy major axes also point toward the 2 cluster
dominant galaxies. In the southern significant regions, galaxy planes are
tangential with respect to the clustercentric direction, except close to
(alpha=194.8, delta=27.65) where the orientation is close to -15deg. Part of
the orientations of the minor axes of late type galaxies and of the major axes
of early type galaxies can be explained by a tidal torque model applied to
cosmological filaments and local merging directions. Another part (close to
NGC4889) can be accounted for by collimated infalls. For early type galaxies,
the (alpha=194.8, delta=27.65) region shows orientations that probably result
from processes involving induced star formation.


title: Study of the $B\to X(3872)(\to D^{*0}\bar D^0)K$ decay

abstract:
  We present a study of $B\to X(3872)K$ with X(3872) decaying to $D^{*0}\bar
D^0$ using a sample of 657 million $B\bar B$ pairs recorded at the
$\Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy
$e^+e^-$ collider. Both $D^{*0}\to D^0\gamma$ and $D^{*0}\to D^0\pi^0$ decay
modes are used. We find a peak of $50.1^{+14.8}_{-11.1}$ events with a mass of
$(3872.9^{+0.6 +0.4}_{-0.4 -0.5}){\rm MeV}/c^2$, a width of $(3.9^{+2.8
+0.2}_{-1.4 -1.1}){\rm MeV}/c^2$ and a product branching fraction ${\cal
B}(B\to X(3872)K)\times{\cal B}(X(3872)\to D^{*0}\bar
D^0)=(0.80\pm0.20\pm0.10)\times10^{-4}$, where the first errors are statistical
and the second ones are systematic. The significance of the signal is
$6.4\sigma$. The difference between the fitted mass and the $D^{*0}\bar D^0$
threshold is calculated to be $(1.1^{+0.6 +0.1}_{-0.4 -0.3}){\rm MeV}/c^2$. We
also obtain an upper limit on the product of branching fractions ${\cal B}(B\to
Y(3940)K)\times{\cal B}(Y(3940)\to D^{*0}\bar D^0)$ of $0.67\times10^{-4}$ at
90% CL.


title:
Commutative rings in which every finitely generated ideal is
  quasi-projective

abstract:
  This paper studies the multiplicative ideal structure of commutative rings in
which every finitely generated ideal is quasi-projective. Section 2 provides
some preliminaries on quasi-projective modules over commutative rings. Section
3 investigates the correlation with well-known Prufer conditions; namely, we
prove that this class of rings stands strictly between the two classes of
arithmetical rings and Gaussian rings. Thereby, we generalize Osofsky's theorem
on the weak global dimension of arithmetical rings and partially resolve
Bazzoni-Glaz's related conjecture on Gaussian rings. We also establish an
analogue of Bazzoni-Glaz results on the transfer of Prufer conditions between a
ring and its total ring of quotients. Section 4 examines various contexts of
trivial ring extensions in order to build new and original examples of rings
where all finitely generated ideals are subject to quasi-projectivity, marking
their distinction from related classes of Prufer rings.


title:
Semilinear response for the heating rate of cold atoms in vibrating
  traps

abstract:
  The calculation of the heating rate of cold atoms in vibrating traps requires
a theory that goes beyond the Kubo linear response formulation. If a strong
"quantum chaos" assumption does not hold, the analysis of transitions shows
similarities with a percolation problem in energy space. We show how the
texture and the sparsity of the perturbation matrix, as determined by the
geometry of the system, dictate the result. An improved sparse random matrix
model is introduced: it captures the essential ingredients of the problem, and
leads to a generalized variable range hopping picture.


title: Metallic conduction at organic charge-transfer interfaces

abstract:
  The electronic properties of interfaces between two different solids can
differ strikingly from those of the constituent materials. For instance,
metallic conductivity, and even superconductivity, have been recently
discovered at interfaces formed by insulating transition metal oxides. Here we
investigate interfaces between crystals of conjugated organic molecules, which
are large gap undoped semiconductors, i.e. essentially insulators. We find that
highly conducting interfaces can be realized with resistivity ranging from 1 to
30 kOhm square, and that, for the best samples, the temperature dependence of
the conductivity is metallic. The observed electrical conduction originates
from a large transfer of charge between the two crystals that takes place at
the interface, on a molecular scale. As the interface assembly process is
simple and can be applied to crystals of virtually any conjugated molecule, the
conducting interfaces described here represent the first examples of a new
class of electronic systems.


title:
Renormalized theory of the ion cyclotron turbulence in magnetic
  field--aligned plasma shear flow

abstract:
  The analytical treatment of nonlinear evolution of the shear-flow-modified
current driven ion cyclotron instability and shear-flow-driven ion cyclotron
kinetic instabilities of magnetic field--aligned plasma shear flow is
presented. Analysis is performed on the base of the nonlinear dispersion
equation, which accounts for a new combined effect of plasma turbulence and
shear flow. It consists in turbulent scattering of ions across the shear flow
with their convection by shear flow and results in enhanced nonlinear
broadening of ion cyclotron resonances. This effect is found to lead to the
saturation of ion cyclotron instabilities as well as to the development of
nonlinear shear flow driven ion cyclotron instability. 52.35.Ra


title: Space-time dimensionality from brane collisions

abstract:
  Collisions and subsequent decays of higher dimensional branes leave behind
three-dimensional branes and anti-branes, one of which could play the role of
our universe. This process also leads to the production of one-dimensional
branes and anti-branes, however their number is expected to be suppressed.
Brane collisions may also lead to the formation of bound states of branes.
Their existence does not alter this result, it just allows for the existence of
one-dimensional branes captured within the three-dimensional ones.


title:
Robust Asymptotic Stabilization of Nonlinear Systems with Non-Hyperbolic
  Zero Dynamics

abstract:
  In this paper we present a general tool to handle the presence of zero
dynamics which are asymptotically but not locally exponentially stable in
problems of robust nonlinear stabilization by output feedback. We show how it
is possible to design locally Lipschitz stabilizers under conditions which only
rely upon a partial detectability assumption on the controlled plant, by
obtaining a robust stabilizing paradigm which is not based on design of
observers and separation principles. The main design idea comes from recent
achievements in the field of output regulation and specifically in the design
of nonlinear internal models.


title: On o-minimal homotopy groups

abstract:
  We work over an o-minimal expansion of a real closed field. The o-minimal
homotopy groups of a definable set are defined naturally using definable
continuous maps. We prove that any two semialgebraic maps which are definably
homotopic are also semialgebraically homotopic. This result together with the
study of semialgebraic homotopy done by H. Delfs and M. Knebusch allows us to
develop an o-minimal homotopy theory. In particular, we obtain o-minimal
versions of the Hurewicz theorems and the Whitehead theorem.


title:
Single eta production in heavy quarkonia: breakdown of multipole
  expansion

abstract:
  The $\eta$ production in the $(n,n')$ bottomonium transitions $\Upsilon (n)
\to \Upsilon (n') \eta, $ is studied in the method used before for dipion heavy
quarkonia transitions. The widths $\Gamma_\eta(n,n')$ are calculated without
fitting parameters for $n=2,3,4,5, n'=1$. Resulting $\Gamma_\eta(4,1)$ is found
to be large in agreement with recent data. Multipole expansion method is shown
to be inadequate for large size systems considered.


title:
Motion of influential players can support cooperation in Prisoner's
  Dilemma

abstract:
  We study a spatial Prisoner's dilemma game with two types (A and B) of
players located on a square lattice. Players following either cooperator or
defector strategies play Prisoner's Dilemma games with their 24 nearest
neighbors. The players are allowed to adopt one of their neighbor's strategy
with a probability dependent on the payoff difference and type of the given
neighbor. Players A and B have different efficiency in the transfer of their
own strategy therefore the strategy adoption probability is reduced by a
multiplicative factor (w < 1) from the players of type B. We report that the
motion of the influential payers (type A) can improve remarkably the
maintenance of cooperation even for their low densities.


title: Isometric action of SL(2,R) on homogeneous spaces

abstract:
  We investigate the SL(2,R) invariant geodesic curves with the as- sociated
invariant distance function in parabolic geometry. Parabolic geom- etry
naturally occurs in the study of SL(2,R) and is placed in between the elliptic
and the hyperbolic (also known as the Lobachevsky half-plane and 2- dimensional
Minkowski half-plane space-time) geometries. Initially we attempt to use
standard methods of finding geodesics but they lead to degeneracy in this
setup. Instead, by studying closely the two related elliptic and hyperbolic
geometries we discover a unified approach to a more exotic and less obvious
parabolic case. With aid of common invariants we describe the possible dis-
tance functions that turn out to have some unexpected, interesting properties.


title:
Evidence for dielectric aging due to progressive 180 domain wall pinning
  in polydomain Pb(Zr0.45Ti0.55)O3 thin films

abstract:
  An evidence that the dielectric ageing in the polydomain Pb(Zr0.45Ti0.55)O3
thin films is controlled by progressive pinning of 180 domain walls is
presented. To provide such a conclusion, we use a general method, which is
based on the study of the time evolution of the nonlinear, but anhysteretic,
dielectric response of the ferroelectric to a weak electric field. A
thermodynamic model of the ferroelectric system where the dielectric response
is controlled by bending movements of pinned 180 domain walls is developed.
Within this model, the nonlinear permittivity of the ferroelectric is expressed
as a function of the microstructural parameters of the domain pattern. It is
shown that using the analysis of the time evolution of the nonlinear
permittivity, it is possible to estimate changes in the concentration of the
pinning centers that block the movements of the 180 domain walls during aging
in polydomain perovskite ferroelectrics.


title:
Nonequilibrium Fluctuation Relation for Sheared Micellar Gel in a Jammed
  State

abstract:
  We show that the shear rate at a fixed shear stress in a micellar gel in a
jammed state exhibits large fluctuations, showing positive and negative values,
with the mean shear rate being positive. The resulting probability distribution
functions (PDF's) of the global power flux to the system vary from Gaussian to
non-Gaussian, depending on the driving stress and in all cases show similar
symmetry properties as predicted by Gallavotti-Cohen steady state fluctuation
relation. The fluctuation relation allows us to determine an effective
temperature related to the structural constraints of the jammed state. We have
measured the stress dependence of the effective temperature. Further,
experiments reveal that the effective temperature and the standard deviation of
the shear rate fluctuations increase with the decrease of the system size.


title: The luminosity of GRB afterglows as distance estimator

abstract:
  We investigate the clustering of afterglow light curves observed at X-ray and
optical wavelengths. We have constructed a sample of 61 bursts with known
distance and X-ray afterglow. GRB sources can be divided in three classes,
namely optical and X-ray bright afterglows, optical and X-ray dim one s, and
optically bright -X-ray dim ones. We argue that this clustering is related to
the fireball total energy, the external medium density, the fraction of
fireball energy going in relativistic electrons and magnetic fields. We propose
a method for the estimation of the GRB source redshift based on the observe d
X-ray flux one day after the burst and optical properties. We tested this
method on three recently detected SWIFT GRBs with known redshift, and found it
i n good agreement with the reported distance from optical spectroscopy.


title:
Optimizing Binary Code Produced by Valgrind (Project Report on Virtual
  Execution Environments Course - AVExe)

abstract:
  Valgrind is a widely used framework for dynamic binary instrumentation and
its mostly known by its memcheck tool. Valgrind's code generation module is far
from producing optimal code. In addition it has many backends for different CPU
architectures, which difficults code optimization in an architecture
independent way. Our work focused on identifying sub-optimal code produced by
Valgrind and optimizing it.


title: Optomechanical Stochastic Resonance in a Macroscopic Torsion Oscillator

abstract:
  Linear mechanical oscillators have been applied to measure very small forces,
mostly with the help of noise suppression. In contrast, adding noise to
non-linear oscillators can improve the measurement conditions. Here, this
effect of stochastic resonance is demonstrated in a macroscopic torsion
oscillator, for an optomechanical non-linear potential. The signal output is
enhanced for a sub-threshold electronic signal. This non-linear oscillator
serves as a model system for the enhancement of signal-to-noise ratio in high
precision optomechanical experiments.


title: Lattice QCD thermodynamic results with improved staggered fermions

abstract:
  We present results on the QCD equation of state, obtained with two different
improved dynamical staggered fermion actions and almost physical quark masses.
Lattice cut-off effect are discussed in detail as results for three different
lattice spacings are available now, i.e. results have been obtained on lattices
with temporal extent of $N_\tau=4,6$ and 8. Furthermore we discuss the Taylor
expansion approach to non-zero baryon chemical potential and present the
isentropic equation of state on lines of constant entropy per baryon number.


title:
Non-zero density QCD by the Taylor expansion method: The isentropic
  equation of state, hadronic fluctuations and more

abstract:
  We discuss the Taylor expansion approach to non-zero baryon chemical
potential ($\mu_B$) and present results on expanion coefficients of the
pressure and energy density up to the 6-th order in $\mu_B$. Calculations have
been performed with (2+1)-flavor of improved staggerd fermions (p4fat3) and
almost physical masses on lattices with temporal extent of four and six time
slices. We use the expansion coefficients to construct the isentropic equation
of state on lines of constant entropy per baryon number and various different
hadronic fluctuations. Furthermore, we estimate the radius of convegence of our
expansion, which can be seen as a method to analyze the structure of the QCD
phase diagram.


title:
The Delicate Electronic and Magnetic Structure of the LaOFePn System (Pn
  = pnictogen)

abstract:
  The occurrence of high temperature superconductivity, and the competition
with magnetism, in stoichiometric and doped LaOFeAs and isostructural
iron-oxypnictides is raising many fundamental questions about the electronic
structure and magnetic interactions in this class of materials. There are now
sufficient experimental data that it may be possible to identify the important
issues whose resolution will lead to the understanding of this system. In this
paper we address a number of the important issues. One important characteristic
is the Fe-As distance (or more abstractly the pnictogen (Pn) height $z$(Pn));
we present results for the effect of $z$(Pn) on the electronic structure,
energetics, and Fe magnetic moment. We also study LaOFeAs under pressure, and
investigate the effects of both electron and hole doping within the virtual
crystal approximation. The electric field gradients for all atoms in the
LaOFeAs compound are presented (undoped and doped) and compared with available
data. The observed $(\pi,\pi,\pi)$ magnetic order is studied and compared with
the computationally simpler $(\pi,\pi,0)$ order which is probably a very good
model in most respects. We investigate the crucial role of the pnictogen atom
in this class, and predict the structures and properties of the N and Sb
counterparts that have not yet been reported experimentally. At a certain
volume a gap opens at the Fermi level in LaOFeN, separating bonding from
antibonding bands and suggesting directions for a better simple understanding
of the seemingly intricate electronic structure of this system. Finally, we
address briefly on the possible effects of post-lanthanum rare earths, which
have been observed to enhance the superconducting critical temperature
substantially.


title: A Topologically Massive Gauge Theory with 32 Supercharges

abstract:
  We construct a novel topologically massive abelian Chern-Simons gauge theory
with 32 global supersymmetries in three spacetime dimensions. In spite of the
32 supercharges, the theory exhibits massive excitations only up to spin 1. The
possibility of such a multiplet shortening is due to the presence of
non-central R-symmetry generators in the Poincare superalgebra, whose
supermultiplets are determined.


title:
Drastic changes in the molecular absorption at redshift z=0.89 toward
  the quasar PKS 1830-211

abstract:
  A 12 year-long monitoring of the absorption caused by a z=0.89 spiral galaxy
on the line of sight to the radio-loud gravitationally lensed quasar PKS
1830-211 reveals spectacular changes in the HCO+ and HCN (2-1) line profiles.
The depth of the absorption toward the quasar NE image increased by a factor of
~3 in 1998-1999 and subsequently decreased by a factor >=6 between 2003 and
2006. These changes were echoed by similar variations in the absorption line
wings toward the SW image. Most likely, these variations result from a motion
of the quasar images with respect to the foreground galaxy, which could be due
to a sporadic ejection of bright plasmons by the background quasar. VLBA
observations have shown that the separation between the NE and SW images
changed in 1997 by as much as 0.2 mas within a few months. Assuming that
motions of similar amplitude occurred in 1999 and 2003, we argue that the
clouds responsible for the NE absorption and the broad wings of the SW
absorption should be sparse and have characteristic sizes of 0.5-1 pc.


title:
Crystallization and gelation in colloidal systems with short-ranged
  attractive interactions

abstract:
  We systematically study the relationship between equilibrium and
non-equilibrium phase diagrams of a system of short-ranged attractive colloids.
Using Monte Carlo and Brownian dynamics simulations we find a window of
enhanced crystallization that is limited at high interaction strength by a
slowing down of the dynamics and at low interaction strength by the high
nucleation barrier. We find that the crystallization is enhanced by the
metastable gas-liquid binodal by means of a two-stage crystallization process.
First, the formation of a dense liquid is observed and second the crystal
nucleates within the dense fluid. In addition, we find at low colloid packing
fractions a fluid of clusters, and at higher colloid packing fractions a
percolating network due to an arrested gas-liquid phase separation that we
identify with gelation. We find that this arrest is due to crystallization at
low interaction energy and it is caused by a slowing down of the dynamics at
high interaction strength. Likewise, we observe that the clusters which are
formed at low colloid packing fractions are crystalline at low interaction
energy, but glassy at high interaction energy. The clusters coalesce upon
encounter.


title: Exclusive processes at HERA

abstract:
  An increased precision of HERA data allows studies of exclusive processes in
their transition from soft to hard interactions as well as in the pQCD domain.
The recent measurements of vector meson production and Deeply Virtual Compton
Scattering (DVCS) performed by the H1 and ZEUS experiments are reported and
compared to pQCD expectations.


title: The CMS Electromagnetic Calorimeter at the LHC

abstract:
  The CMS detector at the LHC is in the final stages of preparation. The high
resolution Electromagnetic Calorimeter, which consists of nearly 76000 lead
tungstate crystals, will play a crucial role in the coming physics searches
undertaken by CMS. The design, status, and initial performance of the
calorimeter, in test beams and with cosmic rays, will be reviewed.


title: On the field intersection problem of generic polynomials: a survey

abstract:
  Let $k$ be a field of characteristic $\neq 2$. We survey a general method of
the field intersection problem of generic polynomials via formal Tschirnhausen
transformation. We announce some of our recent results of cubic, quartic and
quintic cases the details of which are to appear elsewhere. In this note, we
give an explicit answer to the problem in the cases of cubic and dihedral
quintic by using multi-resolvent polynomials.


title:
A Lindemann-Weierstrass theorem for semiabelian varieties over function
  fields

abstract:
  We prove an analogue of the Lindemann-Weierstrass theorem (that the
exponentials of Q-linearly independent algebraic numbers are algebraically
independent) for commutative algebraic groups G without unipotent quotients,
over function fields. We concentrate on solutions to the the differential
algebraic relations satisfied by exp from LG to G.


title:
Periodic forcing in a three level cellular automata model for a vector
  transmitted disease

abstract:
  The transmission of vector infectious diseases, which produces complex
spatiotemporal patterns, is analyzed by a periodically forced two-dimensional
cellular automata model. The system, which comprises three population levels,
is introduced to describe complex features of the dynamics of the vector
transmitted dengue epidemics, known to be very sensitive to seasonal variables.
The three coupled levels represent the human, the adult and immature vector
populations. The dynamics includes external seasonality forcing (rainfall
intensity data), human and mosquito mobility, and vector control effects. The
model parameters, even if bounded to well defined intervals obtained from
reported data, can be selected to reproduce specific epidemic outbursts. In the
current study, explicit results are obtained by comparison with actual data
retrieved from the time-series of dengue epidemics in two cities in Brazil. The
results show fluctuations that are not captured by mean-field models. It also
reveals the qualitative behavior of the spatiotemporal patterns of the
epidemics. In the extreme situation of absence of external periodic drive, the
model predicts completely distinct long time evolution. The model is robust in
the sense that it is able to reproduce the time series of dengue epidemics of
different cities, provided the forcing term takes into account the local
rainfall modulation. Finally, the dependence between epidemics threshold and
vector control undergoes a transition from power law to stretched exponential
behavior due to human mobility effect.


title:
Radio Astronomy Data Model for Single-Dish Multiple-Feed Telescopes, and
  Robledo Archive Architecture

abstract:
  All the effort that the astrophysical community has put into the development
of the Virtual Observatory (VO) has surpassed the non-return point: the VO is a
reality today, and an initiative that will self-sustain, and to which all
archival projects must adhere. We have started the design of the scientific
archive for the DSS-63 70-m antenna at NASA's DSN station in Robledo de Chavela
(Madrid). Here we show how we can use all VO proposed data models to build a
VO-compliant single-dish, multiple-feed, radio astronomical archive data model
(RADAMS) suitable for the archival needs of the antenna. We also propose an
exhaustive list of Universal Content Descriptors (UCDs) and FITS keywords for
all relevant metadata. We will further refine this data model with the
experience that we will gain from that implementation.


title:
Absolute versus convective helical magnetorotational instability in a
  Taylor-Couette flow

abstract:
  We analyze numerically the magnetorotational instability of a Taylor-Couette
flow in a helical magnetic field (HMRI) using the inductionless approximation
defined by a zero magnetic Prandtl number (Pm=0). The Chebyshev collocation
method is used to calculate the eigenvalue spectrum for small amplitude
perturbations. First, we carry out a detailed conventional linear stability
analysis with respect to perturbations in the form of Fourier modes that
corresponds to the convective instability which is not in general
self-sustained. The helical magnetic field is found to extend the instability
to a relatively narrow range beyond its purely hydrodynamic limit defined by
the Rayleigh line. There is not only a lower critical threshold at which HMRI
appears but also an upper one at which it disappears again. The latter
distinguishes the HMRI from a magnetically-modified Taylor vortex flow. Second,
we find an absolute instability threshold as well. In the hydrodynamically
unstable regime before the Rayleigh line, the threshold of absolute instability
is just slightly above the convective one although the critical wave length of
the former is noticeably shorter than that of the latter. Beyond the Rayleigh
line the lower threshold of absolute instability rises significantly above the
corresponding convective one while the upper one descends significantly below
its convective counterpart. As a result, the extension of the absolute HMRI
beyond the Rayleigh line is considerably shorter than that of the convective
instability. The absolute HMRI is supposed to be self-sustained and, thus,
experimentally observable without any external excitation in a system of
sufficiently large axial extension.


title: Time Averaged VHE Spectrum of Mrk 421 in 2005

abstract:
  The blazar Mrk421 was observed independently, but contemporaneously, in 2005
at TeV energies by MAGIC, the Whipple 10m telescope, and by a single VERITAS
telescope during the construction phase of operations. A comparison of the time
averaged spectra, in what was a relatively quiescent state, demonstrates the
level of agreement between instruments. In addition, the increased sensitivity
of the new generation instruments, and ever decreasing energy thresholds,
questions how best to compare new observational data with archival results.


title: Pointwise estimates for the Bergman kernel of the weighted Fock space

abstract:
  We prove upper pointwise estimates for the Bergman kernel of the weighted
Fock space of entire functions in $L^2(e^{-2\phi})$ where $\phi$ is a
subharmonic function with $\Delta \phi$ a doubling measure. We derive estimates
for the canonical solution operator to the inhomogeneous Cauchy-Riemann
equation and we characterize the compactness of this operator in terms of
$\Delta \phi$.


title:
Voltage controlled inversion of magnetic anisotropy in a ferromagnetic
  thin film at room temperature

abstract:
  The control of magnetic properties by means of an electric field is an
important aspect in magnetism and magnetoelectronics. We here utilize
magnetoelastic coupling in ferromagnetic/piezoelectric hybrids to realize a
voltage control of magnetization orientation at room temperature. The samples
consist of polycrystalline nickel thin films evaporated onto piezoelectric
actuators. The magnetic properties of these multifunctional hybrids are
investigated at room temperature as a function of the voltage controlled stress
exerted by the actuator on the Ni film. Ferromagnetic resonance spectroscopy
shows that the magnetic easy axis in the Ni film plane is rotated by 90 degree
upon changing the polarity of the voltage Vp applied to the actuator. In other
words, the in-plane uniaxial magnetic anisotropy of the Ni film can be inverted
via the application of an appropriate voltage Vp. Using SQUID magnetometry, the
evolution of the magnetization vector is recorded as a function of Vp and of
the external magnetic field. Changing Vp allows to reversibly adjust the
magnetization orientation in the Ni film plane within a range of approximately
70 degree. All magnetometry data can be quantitatively understood in terms of
the magnetic free energy determined from the ferromagnetic resonance
experiments. These results demonstrate that magnetoelastic coupling in hybrid
structures indeed is a viable option to control magnetization orientation in
technologically relevant ferromagnetic thin films at room temperature.