title: A probable giant planet imaged in the Beta Pictoris disk

abstract:
  Since the discovery of its dusty disk in 1984, Beta Pictoris has become the
prototype of young early-type planetary systems, and there are now various
indications that a massive Jovian planet is orbiting the star at ~ 10 AU.
However, no planets have been detected around this star so far. Our goal was to
investigate the close environment of Beta Pic, searching for planetary
companion(s). Deep adaptive-optics L'-band images of Beta Pic were recorded
using the NaCo instrument at the Very Large Telescope. A faint point-like
signal is detected at a projected distance of ~ 8 AU from the star, within the
North-East side of the dust disk. Various tests were made to rule out with a
good confidence level possible instrumental or atmospheric artifacts. The
probability of a foreground or background contaminant is extremely low, based
in addition on the analysis of previous deep Hubble Space Telescope images. The
object L'=11.2 apparent magnitude would indicate a typical temperature of ~1500
K and a mass of ~ 8 Jovian masses. If confirmed, it could explain the main
morphological and dynamical peculiarities of the Beta Pic system. The present
detection is unique among A-stars by the proximity of the resolved planet to
its parent star. Its closeness and location inside the Beta Pic disk suggest a
formation process by core accretion or disk instabilities rather than a
binary-like formation process.


title:
Density-dependence of functional development in spiking cortical
  networks grown in vitro

abstract:
  During development, the mammalian brain differentiates into specialized
regions with distinct functional abilities. While many factors contribute to
functional specialization, we explore the effect of neuronal density on the
development of neuronal interactions in vitro. Two types of cortical networks,
dense and sparse, with 50,000 and 12,000 total cells respectively, are studied.
Activation graphs that represent pairwise neuronal interactions are constructed
using a competitive first response model. These graphs reveal that, during
development in vitro, dense networks form activation connections earlier than
sparse networks. Link entropy analysis of dense net- work activation graphs
suggests that the majority of connections between electrodes are reciprocal in
nature. Information theoretic measures reveal that early functional information
interactions (among 3 cells) are synergetic in both dense and sparse networks.
However, during later stages of development, previously synergetic
relationships become primarily redundant in dense, but not in sparse networks.
Large link entropy values in the activation graph are related to the domination
of redundant ensembles in late stages of development in dense networks. Results
demonstrate differences between dense and sparse networks in terms of
informational groups, pairwise relationships, and activation graphs. These
differences suggest that variations in cell density may result in different
functional specialization of nervous system tissue in vivo.


title: The Capacity of Ad hoc Networks under Random Packet Losses

abstract:
  We consider the problem of determining asymptotic bounds on the capacity of a
random ad hoc network. Previous approaches assumed a link layer model in which
if a transmitter-receiver pair can communicate with each other, i.e., the
Signal to Interference and Noise Ratio (SINR) is above a certain threshold,
then every transmitted packet is received error-free by the receiver thereby.
Using this model, the per node capacity of the network was shown to be
$\Theta(\frac{1}{\sqrt{n\log{n}}})$. In reality, for any finite link SINR,
there is a non-zero probability of erroneous reception of the packet. We show
that in a large network, as the packet travels an asymptotically large number
of hops from source to destination, the cumulative impact of packet losses over
intermediate links results in a per-node throughput of only $O(\frac{1}{n})$.
We then propose a new scheduling scheme to counter this effect. The proposed
scheme provides tight guarantees on end-to-end packet loss probability, and
improves the per-node throughput to $\Omega(\frac{1}{\sqrt{n}
({\log{n}})^{\frac{\alpha{{+2}}}{2(\alpha-2)}}})$ where $\alpha>2$ is the path
loss exponent.


title: Glauber - Gribov approach for DIS on nuclei in N=4 SYM

abstract:
  In this paper the Glauber-Gribov approach for deep-inelastic scattering (DIS)
with nuclei is developed in N=4 SYM. It is shown that the amplitude displays
the same general properties, such as geometrical scaling, as is the case in the
high density QCD approach. We found that the quantum effects leading to the
graviton reggeization, give rise to an imaginary part of the nucleon amplitude,
which makes the DIS in N=4 SYM almost identical to the one expected in high
density QCD. We concluded that the impact parameter dependence of the nucleon
amplitude is very essential for N=4 SYM, and the entire kinematic region can be
divided into three regions which are discussed in the paper. We revisited the
dipole description for DIS and proposed a new renormalized Lagrangian for the
shock wave formalism which reproduces the Glauber-Gribov approach in a certain
kinematic region. However the saturation momentum turns out to be independent
of energy, as it has been discussed by Albacete, Kovchegov and Taliotis. We
discuss the physical meaning of such a saturation momentum $Q_s(A)$ and argue
that one can consider only $Q>Q_s(A)$ within the shock wave approximation.


title:
Automated and accurate protein structure description: Distribution of
  Ideal Secondary Structural Units in Natural Proteins

abstract:
  A new method for the Automated Protein Structure Analysis (APSA) is derived,
which simplifies the protein backbone to a smooth curve in 3-dimensional space.
For the purpose of obtaining this smooth line each amino acid is represented by
its C$_{\alpha}$ atom, which serves as suitable anchor point for a cubic spline
fit. The backbone line is characterized by arc length $s$, curvature
$\kappa(s)$, and torsion $\tau(s)$. The $\kappa(s)$ and $\tau(s)$ diagrams of
the protein backbone suppress, because of the level of coarse graining applied,
details of the bond framework of the backbone, however reveal accurately all
secondary structure features of a protein. Advantages of APSA are its
quantitative representation and analysis of 3-dimensional structure in form of
2-dimensional curvature and torsion patterns, its easy visualization of
complicated conformational features, and its general applicability. Typical
differences between 3$_{10}$-,$\alpha$-, $\pi$-helices, and $\beta$-strands are
quantified with the help of the $\kappa(s)$ and $\tau(s)$ diagrams. For a test
set of 20 proteins, 63 % of all helical residues and 48.5 % of all extended
residues are identified to be in ideal conformational environments with the
help of APSA. APSA is compared with other methods for protein structure
analysis and its applicability to higher levels of protein structure is
discussed.


title:
Approximately dual frame pairs in Hilbert spaces and applications to
  Gabor frames

abstract:
  We discuss the concepts of pseudo-dual frames and approximately dual frames,
and illuminate their relationship to classical frames. Approximately dual
frames are easier to construct than the classical dual frames, and might be
tailored to yield almost perfect reconstruction.
  For approximately dual frames constructed via perturbation theory, we provide
a bound on the deviation from perfect reconstruction. An alternative bound is
derived for the rich class of Gabor frames, by using the Walnut representation
of the frame operator to estimate the deviation from equality in the duality
conditions.
  As illustration of the results, we construct explicit approximate duals of
Gabor frames generated by the Gaussian; these approximate duals yield almost
perfect reconstruction. Amazingly, the method applies also to certain Gabor
frames that are far from being tight.


title: Bit Commitment from Non-Signaling Correlations

abstract:
  Central cryptographic functionalities such as encryption, authentication, or
secure two-party computation cannot be realized in an information-theoretically
secure way from scratch. This serves as a motivation to study what (possibly
weak) primitives they can be based on. We consider as such starting points
general two-party input-output systems that do not allow for message
transmission, and show that they can be used for realizing unconditionally
secure bit commitment as soon as they are non-trivial, i.e., cannot be securely
realized from distributed randomness only.


title: Silica in Protoplanetary Disks

abstract:
  Mid-infrared spectra of a few T Tauri stars (TTS) taken with the Infrared
Spectrograph (IRS) on board the Spitzer Space Telescope show prominent narrow
emission features indicating silica (crystalline silicon dioxide). Silica is
not a major constituent of the interstellar medium; therefore, any silica
present in the circumstellar protoplanetary disks of TTS must be largely the
result of processing of primitive dust material in the disks surrouding these
stars. We model the silica emission features in our spectra using the opacities
of various polymorphs of silica and their amorphous versions computed from
earth-based laboratory measurements. This modeling indicates that the two
polymorphs of silica, tridymite and cristobalite, which form at successively
higher temperatures and low pressures, are the dominant forms of silica in the
TTS of our sample. These high temperature, low pressure polymorphs of silica
present in protoplanetary disks are consistent with a grain composed mostly of
tridymite named Ada found in the cometary dust samples collected from the
STARDUST mission to Comet 81P/Wild 2. The silica in these protoplanetary disks
may arise from incongruent melting of enstatite or from incongruent melting of
amorphous pyroxene, the latter being analogous to the former. The high
temperatures of 1200K-1300K and rapid cooling required to crystallize tridymite
or cristobalite set constraints on the mechanisms that could have formed the
silica in these protoplanetary disks, suggestive of processing of these grains
during the transient heating events hypothesized to create chondrules.


title: Properties of second generation stars in Globular Clusters

abstract:
  We present the first results from the analysis of GIRAFFE spectra of more
than 1200 red giants stars in 19 Galactic Globular Clusters (GCs), to study the
chemical composition of second generation stars and their link with global
cluster parameters. We confirm that the extension of the Na-O anticorrelation
(the most striking signature of polluted, second generation populations) is
strictly related to the very blue (and hot) extreme of the Horizontal Branch
(HB). Long anticorrelations seem to require large mass and large-sized,
eccentric orbits, taking the GCs far away from the central regions of the
Galaxy. We can separate three populations in each cluster (primordial,
intermediate and extreme) based on the chemical composition. In all GCs we
observe a population of primordial composition, similar to field stars of
similar metallicity. We find that in all GCs the bulk (from 50 to 70%) of stars
belong to the intermediate component. Finally, the extreme, very oxygen-poor
component is observed preferentially in massive clusters, but is not present in
all massive GCs.


title: Magnetic Domains and Surface Effects in Hollow Maghemite Nanoparticles

abstract:
  In the present work, we investigate the magnetic properties of ferrimagnetic
and noninteracting maghemite (g-Fe2O3) hollow nanoparticles obtained by the
Kirkendall effect. From the experimental characterization of their magnetic
behavior, we find that polycrystalline hollow maghemite nanoparticles are
characterized by low superparamagnetic-to-ferromagnetic transition
temperatures, small magnetic moments, significant coercivities and
irreversibility fields, and no magnetic saturation on external magnetic fields
up to 5 T. These results are interpreted in terms of the microstructural
parameters characterizing the maghemite shells by means of an atomistic Monte
Carlo simulation of an individual spherical shell model. The model comprises
strongly interacting crystallographic domains arranged in a spherical shell
with random orientations and anisotropy axis. The Monte Carlo simulation allows
discernment between the influence of the structure polycrystalline and its
hollow geometry, while revealing the magnetic domain arrangement in the
different temperature regimes.


title:
Implementation of higher-order absorbing boundary conditions for the
  Einstein equations

abstract:
  We present an implementation of absorbing boundary conditions for the
Einstein equations based on the recent work of Buchman and Sarbach. In this
paper, we assume that spacetime may be linearized about Minkowski space close
to the outer boundary, which is taken to be a coordinate sphere. We reformulate
the boundary conditions as conditions on the gauge-invariant
Regge-Wheeler-Zerilli scalars. Higher-order radial derivatives are eliminated
by rewriting the boundary conditions as a system of ODEs for a set of auxiliary
variables intrinsic to the boundary. From these we construct boundary data for
a set of well-posed constraint-preserving boundary conditions for the Einstein
equations in a first-order generalized harmonic formulation. This construction
has direct applications to outer boundary conditions in simulations of isolated
systems (e.g., binary black holes) as well as to the problem of
Cauchy-perturbative matching. As a test problem for our numerical
implementation, we consider linearized multipolar gravitational waves in TT
gauge, with angular momentum numbers l=2 (Teukolsky waves), 3 and 4. We
demonstrate that the perfectly absorbing boundary condition B_L of order L=l
yields no spurious reflections to linear order in perturbation theory. This is
in contrast to the lower-order absorbing boundary conditions B_L with L<l,
which include the widely used freezing-Psi_0 boundary condition that imposes
the vanishing of the Newman-Penrose scalar Psi_0.


title: Smooth and irreducible multigraded Hilbert schemes

abstract:
  The multigraded Hilbert scheme parametrizes all homogeneous ideals in a
polynomial ring graded by an abelian group with a fixed Hilbert function. We
prove that any multigraded Hilbert scheme is smooth and irreducible when the
polynomial ring is ZZ[x,y], which establishes a conjecture of Haiman and
Sturmfels.


title:
Complete homogeneous symmetric polynomials in Jucys-Murphy elements and
  the Weingarten function

abstract:
  A connection is made between complete homogeneous symmetric polynomials in
Jucys-Murphy elements and the unitary Weingarten function from random matrix
theory. In particular we show that $h_r(J_1,...,J_n),$ the complete homogeneous
symmetric polynomial of degree $r$ in the JM elements, coincides with the $r$th
term in the asymptotic expansion of the Weingarten function. We use this
connection to determine precisely which conjugacy classes occur in the class
basis resolution of $h_r(J_1,...,J_n),$ and to explicitly determine the
coefficients of the classes of minimal height when $r < n.$ These coefficients,
which turn out to be products of Catalan numbers, are governed by the Moebius
function of the non-crossing partition lattice $NC(n).$


title:
Physical Properties of Four SZE-Selected Galaxy Clusters in the Southern
  Cosmology Survey

abstract:
  We present the optical and X-ray properties of four clusters recently
discovered by the South Pole Telescope (SPT) using the Sunyaev-Zel'dovich
effect (SZE). The four clusters are located in one of the common survey areas
of the southern sky that is also being targeted by the Atacama Cosmology
Telescope (ACT) and imaged by the CTIO Blanco 4-m telescope. Based on publicly
available griz optical images and XMM-Newton and ROSAT X-ray observations we
analyse the physical properties of these clusters and obtain photometric
redshifts, luminosities, richness and mass estimates. Each cluster contains a
central elliptical whose luminosity is consistent with SDSS cluster studies.
Our mass estimates are well above the nominal detection limit of SPT and ACT;
the new SZE clusters are very likely massive systems with M>~5x10^14 M_sun.


title: Reversibility in the diffeomorphism group of the real line

abstract:
  An element of a group is said to be reversible if it is conjugate to its
inverse. We characterise the reversible elements in the group of
diffeomorphisms of the real line, and in the subgroup of order preserving
diffeomorphisms.


title:
Solid 4He and the Supersolid Phase: from Theoretical Speculation to the
  Discovery of a New State of Matter? A Review of the Past and Present Status
  of Research

abstract:
  The possibility of a supersolid state of matter, i.e., a crystalline solid
exhibiting superfluid properties, first appeared in theoretical studies about
forty years ago. After a long period of little interest due to the lack of
experimental evidence, it has attracted strong experimental and theoretical
attention in the last few years since Kim and Chan (Penn State, USA) reported
evidence for nonclassical rotational inertia effects, a typical signature of
superfluidity, in samples of solid 4He. Since this "first observation", other
experimental groups have observed such effects in the response to the rotation
of samples of crystalline helium, and it has become clear that the response of
the solid is extremely sensitive to growth conditions, annealing processes, and
3He impurities. A peak in the specific heat in the same range of temperatures
has been reported as well as anomalies in the elastic behaviour of solid 4He
with a strong resemblance to the phenomena revealed by torsional oscillator
experiments. Very recently, the observation of unusual mass transport in hcp
solid 4He has also been reported, suggesting superflow. From the theoretical
point of view, powerful simulation methods have been used to study solid 4He,
but the interpretation of the data is still rather difficult; dealing with the
question of supersolidity means that one has to face not only the problem of
the coexistence of quantum coherence phenomena and crystalline order, exploring
the realm of spontaneous symmetry breaking and quantum field theory, but also
the problem of the role of disorder, i.e., how defects, such as vacancies,
impurities, dislocations, and grain boundaries, participate in the phase
transition mechanism.


title: A second row Parking Paradox

abstract:
  We consider two variations of the discrete car parking problem where at every
vertex of the integers a car arrives with rate one, now allowing for parking in
two lines. a) The car parks in the first line whenever the vertex and all of
its nearest neighbors are not occupied yet. It can reach the first line if it
is not obstructed by cars already parked in the second line (screening). b) The
car parks according to the same rules, but parking in the first line can not be
obstructed by parked cars in the second line (no screening). In both models, a
car that can not park in the first line will attempt to park in the second
line. If it is obstructed in the second line as well, the attempt is discarded.
We show that both models are solvable in terms of finite-dimensional ODEs. We
compare numerically the limits of first and second line densities, with time
going to infinity. While it is not surprising that model a) exhibits an
increase of the density in the second line from the first line, more remarkably
this is also true for model b), albeit in a less pronounced way.


title:
The Fisher's information and quantum-classical field theory: classical
  statistics similarity

abstract:
  The classical statistics indication for the impossibility to derive quantum
mechanics from classical mechanics is proved. The formalism of the statistical
Fisher information is used. Next the Fisher information as a tool of the
construction of a self-consistent field theory, which joins the quantum theory
and classical field theory, is proposed.


title: Looking to the future: using IR interferometry to study microquasars

abstract:
  Infrared interferometry is currently in a rapid development phase, with new
instrumentation soon achieving milliarcsecond spatial resolutions for faint
sources and astrometry on the order of 10 microarcseconds. For jet studies in
particular, the next generation of instruments will bring us closer to the
event horizon of supermassive black holes such as Sgr A*, and the region where
jet launching must occur. But a new possibility to study microquasars in
general and jet physics in particular may also arise, using techniques similar
to those employed for finding faint exoplanets around stars. The compact,
steady jets observed in the hard state of X-ray binaries display a
flat/inverted spectrum from the lower radio wavelengths up through at least the
far-IR band. Somewhere above this band, a turnover is predicted where the jets
become optically thin, revealing a power-law spectrum. This break may have been
observed directly in GX339-4, but in most sources such a feature is likely
hidden under bright emission from the stellar companion or accretion disk
components. Detecting the exact location of this break would provide a new
constraint on our models of jet physics, since the break frequency is dependent
on the total power, as well as internal density and magnetic field.
Furthermore, knowing the break location combined with the spectral index of the
power-law would help constrain the amount of synchrotron emission contributed
by the jets to the X-ray bands. Along with a summary of some potential
observations requiring less optimal instrumental specifications, I will discuss
a technique which may enable us to discern the jet break, and the chances of
success based on theoretical models applied to some potential target sources.


title: Low-Memory Adaptive Prefix Coding

abstract:
  In this paper we study the adaptive prefix coding problem in cases where the
size of the input alphabet is large. We present an online prefix coding
algorithm that uses $O(\sigma^{1 / \lambda + \epsilon}) $ bits of space for any
constants $\eps>0$, $\lambda>1$, and encodes the string of symbols in $O(\log
\log \sigma)$ time per symbol \emph{in the worst case}, where $\sigma$ is the
size of the alphabet. The upper bound on the encoding length is $\lambda n H
(s) +(\lambda \ln 2 + 2 + \epsilon) n + O (\sigma^{1 / \lambda} \log^2 \sigma)$
bits.


title: Multipartite secret key distillation and bound entanglement

abstract:
  Recently it has been shown that quantum cryptography beyond pure entanglement
distillation is possible and a paradigm for the associated protocols has been
established. Here we systematically generalize the whole paradigm to the
multipartite scenario. We provide constructions of new classes of multipartite
bound entangled states, i.e., those with underlying twisted GHZ structure and
nonzero distillable cryptographic key. We quantitatively estimate the key from
below with help of the privacy squeezing technique.


title:
Positive maps, majorization, entropic inequalities, and detection of
  entanglement

abstract:
  In this paper, we discuss some general connections between the notions of
positive map, weak majorization and entropic inequalities in the context of
detection of entanglement among bipartite quantum systems. First, basing on the
fact that any positive map $\Lambda:M_{d}(\mathbb{C})\to M_{d}(\mathbb{C})$ can
be written as the difference between two completely positive maps
$\Lambda=\Lambda_{1}-\Lambda_{2}$, we propose a possible way to generalize the
Nielsen--Kempe majorization criterion. Then we present two methods of
derivation of some general classes of entropic inequalities useful for the
detection of entanglement. While the first one follows from the aforementioned
generalized majorization relation and the concept of the Schur--concave
decreasing functions, the second is based on some functional inequalities. What
is important is that, contrary to the Nielsen--Kempe majorization criterion and
entropic inequalities, our criteria allow for the detection of entangled states
with positive partial transposition when using indecomposable positive maps. We
also point out that if a state with at least one maximally mixed subsystem is
detected by some necessary criterion based on the positive map $\Lambda$, then
there exist entropic inequalities derived from $\Lambda$ (by both procedures)
that also detect this state. In this sense, they are equivalent to the
necessary criterion $[I\ot\Lambda](\varrho_{AB})\geq 0$. Moreover, our
inequalities provide a way of constructing multi--copy entanglement witnesses
and therefore are promising from the experimental point of view. Finally, we
discuss some of the derived inequalities in the context of recently introduced
protocol of state merging and possibility of approximating the mean value of a
linear entanglement witness.


title: How rapidly do neutron stars spin at birth?

abstract:
  We have studied the X-ray properties of ageing historical core-collapse
supernovae in nearby galaxies, using archival data from Chandra, XMM-Newton and
Swift. We found possible evidence of a young X-ray pulsar in SN 1968D and in
few other sources, but none more luminous than ~ a few 10^{37} erg/s. We
compared the observational limits to the X-ray pulsar luminosity distribution
with the results of Monte Carlo simulations for a range of birth parameters. We
conclude that a pulsar population dominated by periods <~ 40 ms at birth is
ruled out by the data.


title: Large-scale cosmic flows and moving dark energy

abstract:
  Large-scale matter bulk flows with respect to the cosmic microwave background
have very recently been detected on scales 100 Mpc/h and 300 Mpc/h by using two
different techniques showing an excellent agreement in the motion direction.
However, the unexpectedly large measured amplitudes are difficult to understand
within the context of standard LCDM cosmology. In this work we show that the
existence of such a flow could be signaling the presence of moving dark energy
at the time when photons decoupled from matter. We also comment on the relation
between the direction of the CMB dipole and the preferred axis observed in the
quadrupole in this scenario.


title: W-like bound entangled states and secure key distillation

abstract:
  We construct multipartite entangled states with underlying W-type structure
satisfying positive partial transpose (PPT) condition under any (N-1)|1
partition. Then we show how to distill N-partite secure key form the states
using two different methods: direct application of local filtering and novel
random key distillation scheme in which we adopt the idea form recent results
on entanglement distillation. Open problems and possible implications are also
discussed.


title: Aspects of the confinement mechanism in Landau gauge QCD

abstract:
  I analyze the IR fixed point structure of Landau gauge QCD. Precisely the
fixed point with a strong kinematic singularity of the quark-gluon vertex that
proved crucial for the recently proposed confinement mechanism in the quenched
approximation is absent in dynamical QCD. Therefore, the IR singularities do
not induce asymptotic quark confinement but the long-range interaction is
screened by unquenching loops at scales of the order of the quark mass. This
provides the prerequisite for a microscopic description of deconfinement and
string breaking. The fixed points determine the qualitative form of the heavy
quark potential and may be relevant for hot and dense matter.


title: Growth of Knowledge and Entropy in Quantum Physics

abstract:
  Most attempts to argue for the second law of thermodynamics fail because (1)
they use the unviable frequency theory of probability and (2) they do not
explain why the arrow of time seen in experiments is aligned with the
thermodynamic arrow of time. I use the decision theoretic interpretation of
quantum probability from the many worlds interpretation of quantum mechanics to
solve the probability problem. I then derive a correlation between the
knowledge arrow of time and the entropy arrow of time using physical
constraints on knowledge creation imposed by Popper's evolutionary theory of
knowledge and the many worlds interpretation.


title:
Type Ia Supernova: Calculations of Turbulent Flames Using the Linear
  Eddy Model

abstract:
  The nature of carbon burning flames in Type Ia supernovae is explored as they
interact with Kolmogorov turbulence. One-dimensional calculations using the
Linear Eddy Model of Kerstein (1991) elucidate three regimes of turbulent
burning. In the simplest case, large scale turbulence folds and deforms thin
laminar flamelets to produce a flame brush with a total burning rate given
approximately by the speed of turbulent fluctuations on the integral scale,
U_L. This is the regime where the supernova explosion begins and where most of
its pre-detonation burning occurs. As the density declines, turbulence starts
to tear the individual flamelets, making broader structures that move faster.
For a brief time, these turbulent flamelets are still narrow compared to their
spacing and the concept of a flame brush moving with an overall speed of U_L
remains valid. However, the typical width of the individual flamelets, which is
given by the condition that their turnover time equals their burning time,
continues to increase as the density declines. Eventually, mixed regions almost
as large as the integral scale itself are transiently formed. At that point, a
transition to detonation can occur. The conditions for such a transition are
explored numerically and it is estimated that the transition will occur for
densities near 1 x 10**7 g/cm**3, provided the turbulent speed on the integral
scale exceeds about 15% sonic. An example calculation shows the details of a
detonation actually developing.


title:
Nucleation of interfacial shear cracks in thin films on disordered
  substrates

abstract:
  We formulate a theoretical model of the shear failure of a thin film tethered
to a rigid substrate. The interface between film and substrate is modeled as a
cohesive layer with randomly fluctuating shear strength/fracture energy. We
demonstrate that, on scales large compared with the film thickness, the
internal shear stresses acting on the interface can be approximated by a
second-order gradient of the shear displacement across the interface. The model
is used to study one-dimensional shear cracks, for which we evaluate the
stress-dependent probability of nucleation of a critical crack. This is used to
determine the interfacial shear strength as a function of film geometry and
statistical properties of the interface.


title: Photon-Photon Entanglement with a Single Trapped Atom

abstract:
  An experiment is performed where a single rubidium atom trapped within a
high-finesse optical cavity emits two independently triggered entangled
photons. The entanglement is mediated by the atom and is characterized both by
a Bell inequality violation of S=2.5, as well as full quantum-state tomography,
resulting in a fidelity exceeding F=90%. The combination of cavity-QED and
trapped atom techniques makes our protocol inherently deterministic - an
essential step for the generation of scalable entanglement between the nodes of
a distributed quantum network.


title: Solutions to the modified Poschl-Teller Potential in D-dimensions

abstract:
  An approximate solution of the $D$-dimensional Schr$\ddot{o}$dinger equation
with the modified P$\ddot{o}$schl-Teller potential is obtained with an
approximation of the centrifugal term. Solution to the corresponding
hyper-radial equation is given using the conventional Nikiforov-Uvarov method.
The normalization constants for the P$\ddot{o}$schl-Teller potential are also
computed. The expectation values $<r^{-2}>$,$<V(r)>$, are also obtained using
the Feynman-Hellmann theorem.


title: Non-LTE line formation for Pr II and Pr III in A and Ap stars

abstract:
  Non-LTE line formation for Pr II and Pr III is considered through a range of
effective temperatures between 7250 K and 9500 K. A comprehensive model atom
for Pr II/III is based on the measured and the predicted energy levels, in
total, 6708 levels of Pr II and Pr III. We describe calculations of the Pr II
energy levels and oscillator strengths for the transitions in Pr II and Pr III.
The influence of departures from LTE on Pr abundance determinations is
evaluated. At Teff >= 8000 K departures from LTE lead to overionization of Pr
II and to systematically depleted total absorption in the line and positive
abundance corrections. At the lower temperatures, different lines of Pr II may
be either weakened or amplified depending on the line strength. The non-LTE
effects strengthen the Pr III lines and lead to negative abundance corrections.
Non-LTE corrections grow with effective temperature for the Pr II lines, and,
in contrast, they decline for the Pr III lines. The Pr II/III model atom is
applied to determine the Pr abundance in the atmosphere of the roAp star HD
24712 from the lines of two ionization stages. In the chemically uniform
atmosphere with [Pr/H] = 3, the departures from LTE may explain only small part
(0.3 dex) of the difference between the LTE abundances derived from the Pr II
and Pr III lines (2 dex). We find that the lines of both ionization stages are
described for the vertical distribution of the praseodymium where the Pr
enriched layer with [Pr/H] > 4 exists in the outer atmosphere at log tau_5000 <
-4. The departures from LTE for Pr II/III are strong in the stratified
atmosphere and have the opposite sign for the Pr II and Pr III lines. Using the
revised partition function of Pr II and experimental transition probabilities,
we determine the solar non-LTE abundance of Pr as log (Pr/H) = -11.15\pm0.08.


title: Generalized Kahler geometry and gerbes

abstract:
  We introduce and study the notion of a biholomorphic gerbe with connection.
The biholomorphic gerbe provides a natural geometrical framework for
generalized Kahler geometry in a manner analogous to the way a holomorphic line
bundle is related to Kahler geometry. The relation between the gerbe and the
generalized Kahler potential is discussed.


title: A note on quantum error correction with continuous variables

abstract:
  We demonstrate that continuous-variable quantum error correction based on
Gaussian ancilla states and Gaussian operations (for encoding, syndrome
extraction, and recovery) can be very useful to suppress the effect of
non-Gaussian error channels. For a certain class of stochastic error models,
reminiscent of those typically considered in the qubit case, quantum error
correction codes designed for single-channel errors may enhance the transfer
fidelities even when errors occur in every channel employed for transmitting
the encoded state. In fact, in this case, the error-correcting capability of
the continuous-variable scheme turns out to be higher than that of its
discrete-variable analogues.


title:
Distributed Scalar Quantization for Computing: High-Resolution Analysis
  and Extensions

abstract:
  Communication of quantized information is frequently followed by a
computation. We consider situations of \emph{distributed functional scalar
quantization}: distributed scalar quantization of (possibly correlated) sources
followed by centralized computation of a function. Under smoothness conditions
on the sources and function, companding scalar quantizer designs are developed
to minimize mean-squared error (MSE) of the computed function as the quantizer
resolution is allowed to grow. Striking improvements over quantizers designed
without consideration of the function are possible and are larger in the
entropy-constrained setting than in the fixed-rate setting. As extensions to
the basic analysis, we characterize a large class of functions for which
regular quantization suffices, consider certain functions for which asymptotic
optimality is achieved without arbitrarily fine quantization, and allow limited
collaboration between source encoders. In the entropy-constrained setting, a
single bit per sample communicated between encoders can have an
arbitrarily-large effect on functional distortion. In contrast, such
communication has very little effect in the fixed-rate setting.


title:
Far-Ultraviolet Observations of Starburst Galaxies with FUSE: Galactic
  Feedback in the Local Universe

abstract:
  We have analysed FUSE far-UV spectra of a sample of 16 local starbursts.
These galaxies span ranges of almost three orders-of-magnitude in star
formation rate and over two orders-of-magnitude in stellar mass. We find that
the strongest interstellar absorption-lines are generally blueshifted relative
to the galaxy systemic velocity by ~50 to 300 km/s, implying the presence of
starburst-driven galactic outflows. The outflow velocites increase on-average
with the star formation rate and the star formation rate per unit mass. We find
that outflowing coronal-phase (T ~ several hundred thousand K) gas detected via
the OVI 1032 absorption line in nearly every galaxy. The kinematics of this
outflowing gas differs from the lower-ionization material, and agrees with
predictions for radiatively cooling gas (most likely created at the interface
between the hot outrushing gas traced by X-rays and cool ambient material).
Emission from the coronal gas is not generally detected, implying that
radiative cooling by this phase is not affecting the dynamics/energetics of the
wind. We find that the weaker interstellar absorption lines lie close to the
systemic velocity, implying that the outflowing gas has a lower column density
than the quiescent gas in the starburst. From direct observation below the
Lyman edge and from the small residual intensity at the core of the CII 1036
line, we conclude that the absolute escape fraction of ionizing radiation is
small (typically less than a few percent). This sample provides a unique window
on the global properties of local starburst galaxies and a useful comparison
sample for understanding spectra of high redshift galaxies.


title: Random Forests: some methodological insights

abstract:
  This paper examines from an experimental perspective random forests, the
increasingly used statistical method for classification and regression problems
introduced by Leo Breiman in 2001. It first aims at confirming, known but
sparse, advice for using random forests and at proposing some complementary
remarks for both standard problems as well as high dimensional ones for which
the number of variables hugely exceeds the sample size. But the main
contribution of this paper is twofold: to provide some insights about the
behavior of the variable importance index based on random forests and in
addition, to propose to investigate two classical issues of variable selection.
The first one is to find important variables for interpretation and the second
one is more restrictive and try to design a good prediction model. The strategy
involves a ranking of explanatory variables using the random forests score of
importance and a stepwise ascending variable introduction strategy.


title: Solving package dependencies: from EDOS to Mancoosi

abstract:
  Mancoosi (Managing the Complexity of the Open Source Infrastructure) is an
ongoing research project funded by the European Union for addressing some of
the challenges related to the "upgrade problem" of interdependent software
components of which Debian packages are prototypical examples. Mancoosi is the
natural continuation of the EDOS project which has already contributed tools
for distribution-wide quality assurance in Debian and other GNU/Linux
distributions. The consortium behind the project consists of several European
public and private research institutions as well as some commercial GNU/Linux
distributions from Europe and South America. Debian is represented by a small
group of Debian Developers who are working in the ranks of the involved
universities to drive and integrate back achievements into Debian. This paper
presents relevant results from EDOS in dependency management and gives an
overview of the Mancoosi project and its objectives, with a particular focus on
the prospective benefits for Debian.


title: Description of the CUDF Format

abstract:
  This document contains several related specifications, together they describe
the document formats related to the solver competition which will be organized
by Mancoosi. In particular, this document describes: - DUDF (Distribution
Upgradeability Description Format), the document format to be used to submit
upgrade problem instances from user machines to a (distribution-specific)
database of upgrade problems; - CUDF (Common Upgradeability Description
Format), the document format used to encode upgrade problems, abstracting over
distribution-specific details. Solvers taking part in the competition will be
fed with input in CUDF format.


title:
Dust Processing and Grain Growth in Protoplanetary Disks in the
  Taurus-Auriga Star-Forming Region

abstract:
  Mid-infrared spectra of 65 T Tauri stars (TTS) taken with the Infrared
Spectrograph (IRS) on board the Spitzer Space Telescope are modeled using dust
at two temperatures to probe the radial variation in dust composition in the
uppermost layers of protoplanetary disks. Most spectra indicating crystalline
silicates require Mg-rich minerals and silica, but a few suggest otherwise.
Spectra indicating abundant enstatite at higher temperatures also require
crystalline silicates at temperatures lower than those required for spectra
showing high abundance of other crystalline silicates. A few spectra show 10
micron complexes of very small equivalent width. They are fit well using
abundant crystalline silicates but very few large grains, inconsistent with the
expectation that low peak-to-continuum ratio of the 10 micron complex always
indicates grain growth. Most spectra in our sample are fit well without using
the opacities of large crystalline silicate grains. If large grains grow by
agglomeration of submicron grains of all dust types, the amorphous silicate
components of these aggregates must typically be more abundant than the
crystalline silicate components. Crystalline silicate abundances correlate
positively with other such abundances, suggesting that crystalline silicates
are processed directly from amorphous silicates and that neither forsterite,
enstatite, nor silica are intermediate steps when producing either of the other
two. Disks with more dust settling typically have greater crystalline
abundances. Large-grain abundance is somewhat correlated with greater settling
of disks. The lack of strong correlation is interpreted to mean that settling
of large grains is sensitive to individual disk properties. Lower-mass stars
have higher abundances of large grains in their inner regions.


title: Superfluid-density of the ultra-cold Fermi gas in optical lattices

abstract:
  In this paper we study the superfluid density of the two component Fermi gas
in optical lattices with population imbalance. Three different type of phases,
the BCS-state (Bardeen, Cooper, and Schrieffer), the FFLO-state (Fulde, Ferrel,
Larkin, and Ovchinnikov), and the Sarma state, are considered. We show that the
FFLO superfluid density differs from the BCS/Sarma superfluid density in an
important way. Although there are dynamical instabilities in the FFLO phase,
when the interaction is strong or densities are high, on the weak coupling
limit the FFLO phase is found to be stable.


title:
Proof of the MHV vertex expansion for all tree amplitudes in N=4 SYM
  theory

abstract:
  We prove the MHV vertex expansion for all tree amplitudes of N=4 SYM theory.
The proof uses a shift acting on all external momenta, and we show that every
N^kMHV tree amplitude falls off as 1/z^k, or faster, for large z under this
shift. The MHV vertex expansion allows us to derive compact and efficient
generating functions for all N^kMHV tree amplitudes of the theory. We also
derive an improved form of the anti-NMHV generating function. The proof leads
to a curious set of sum rules for the diagrams of the MHV vertex expansion.


title: Approximation of the acoustic radiation impedance of a cylindrical pipe

abstract:
  Useful approximation formulae for radiation impedance are given for the
reflection coefficients of both infinitely flanged and unflanged rigid-walled
cylindrical ducts. The expressions guarantee that simple but necessary physical
and mathematical principles are met, like hermitian symmetry for the reflection
coefficient (identical behaviour of positive and negative frequencies) and
causality for the impulse response. A non causal but more accurate expression
is also proposed that is suitable for frequency-domain applications. The
formulae are obtained by analytical and numerical fitting to reference results
from Levine & Schwinger for the unflanged case and extracted from the radiation
impedance matrix given by Zorumski for the infinite flanged case.


title: The Hulthen Potential in D-dimensions

abstract:
  An approximate solution of the Schrodinger equation with the
Hulth$\acute{e}$n potential is obtained in D-dimensions with an exponential
approximation of the centrifugal term. Solution to the corresponding
hyper-radial equation is given using the conventional Nikiforov-Uvarov method.
The normalization constants for the Hulth$\acute{e}$n potential are also
computed. The expectation values $<r^{-2}>$,$<V(r)>$, are also obtained using
the Feynman-Hellmann theorem.


title: Interpenetration as a Mechanism for Liquid-Liquid Phase Transitions

abstract:
  We study simple lattice systems to demonstrate the influence of
interpenetrating bond networks on phase behavior. We promote interpenetration
by using a Hamiltonian with a weakly repulsive interaction with nearest
neighbors and an attractive interaction with second-nearest neighbors. In this
way, bond networks will form between second-nearest neighbors, allowing for two
(locally) distinct networks to form. We obtain the phase behavior from analytic
solution in the mean-field approximation and exact solution on the Bethe
lattice. We compare these results with exact numerical results for the phase
behavior from grand canonical Monte Carlo simulations on square, cubic, and
tetrahedral lattices. All results show that these simple systems exhibit rich
phase diagrams with two fluid-fluid critical points and three thermodynamically
distinct phases. We also consider including third-nearest-neighbor
interactions, which give rise to a phase diagram with four critical points and
five thermodynamically distinct phases. Thus the interpenetration mechanism
provides a simple route to generate multiple liquid phases in single-component
systems, such as hypothesized in water and observed in several model and
experimental systems. Additionally, interpenetration of many such networks
appears plausible in a recently considered material made from nanoparticles
functionalized by single strands of DNA.


title:
High-dimensional covariance estimation by minimizing $\ell_1$-penalized
  log-determinant divergence

abstract:
  Given i.i.d. observations of a random vector $X \in \mathbb{R}^p$, we study
the problem of estimating both its covariance matrix $\Sigma^*$, and its
inverse covariance or concentration matrix {$\Theta^* = (\Sigma^*)^{-1}$.} We
estimate $\Theta^*$ by minimizing an $\ell_1$-penalized log-determinant Bregman
divergence; in the multivariate Gaussian case, this approach corresponds to
$\ell_1$-penalized maximum likelihood, and the structure of $\Theta^*$ is
specified by the graph of an associated Gaussian Markov random field. We
analyze the performance of this estimator under high-dimensional scaling, in
which the number of nodes in the graph $p$, the number of edges $s$ and the
maximum node degree $d$, are allowed to grow as a function of the sample size
$n$. In addition to the parameters $(p,s,d)$, our analysis identifies other key
quantities covariance matrix $\Sigma^*$; and (b) the $\ell_\infty$ operator
norm of the sub-matrix $\Gamma^*_{S S}$, where $S$ indexes the graph edges, and
$\Gamma^* = (\Theta^*)^{-1} \otimes (\Theta^*)^{-1}$; and (c) a mutual
incoherence or irrepresentability measure on the matrix $\Gamma^*$ and (d) the
rate of decay $1/f(n,\delta)$ on the probabilities $ \{|\hat{\Sigma}^n_{ij}-
\Sigma^*_{ij}| > \delta \}$, where $\hat{\Sigma}^n$ is the sample covariance
based on $n$ samples. Our first result establishes consistency of our estimate
$\hat{\Theta}$ in the elementwise maximum-norm. This in turn allows us to
derive convergence rates in Frobenius and spectral norms, with improvements
upon existing results for graphs with maximum node degrees $d = o(\sqrt{s})$.
In our second result, we show that with probability converging to one, the
estimate $\hat{\Theta}$ correctly specifies the zero pattern of the
concentration matrix $\Theta^*$.


title: Characterising the Gravitational Instability in Cooling Accretion Discs

abstract:
  We perform numerical analyses of the structure induced by gravitational
instabilities in cooling gaseous accretion discs. For low enough cooling rates
a quasi-steady configuration is reached, with the instability saturating at a
finite amplitude in a marginally stable disc. We find that the saturation
amplitude scales with the inverse square root of the cooling parameter beta =
t_cool / t_dyn, which indicates that the heating rate induced by the
instability is proportional to the energy density of the induced density waves.
We find that at saturation the energy dissipated per dynamical time by weak
shocks due is of the order of 20 per cent of the wave energy. From Fourier
analysis of the disc structure we find that while the azimuthal wavenumber is
roughly constant with radius, the mean radial wavenumber increases with radius,
with the dominant mode corresponding to the locally most unstable wavelength.
We demonstrate that the density waves excited in relatively low mass discs are
always close to co-rotation, deviating from it by approximately 10 per cent.
This can be understood in terms of the flow Doppler-shifted phase Mach number
-- the pattern speed self-adjusts so that the flow into spiral arms is always
sonic. This has profound effects on the degree to which transport through
self-gravity can be modelled as a viscous process. Our results thus provide (a)
a detailed description of how the self-regulation mechanism is established for
low cooling rates, (b) a clarification of the conditions required for
describing the transport induced by self-gravity through an effective
viscosity, (c) an estimate of the maximum amplitude of the density perturbation
before fragmentation occurs, and (d) a simple recipe to estimate the density
perturbation in different thermal regimes.


title:
Geodesic dynamo chaotic flows and non-Anosov maps in twisted magnetic
  flux tubes

abstract:
  Recently Tang and Boozer [{\textbf{Phys. Plasmas (2000)}}], have investigated
the anisotropies in magnetic field dynamo evolution, from local Lyapunov
exponents, giving rise to a metric tensor, in the Alfven twist in magnetic flux
tubes (MFTs). Thiffeault and Boozer [\textbf{Chaos}(2001)] have investigated
the how the vanishing of Riemann curvature constrained the Lyapunov exponential
stretching of chaotic flows. In this paper, Tang-Boozer-Thiffeault differential
geometric framework is used to investigate effects of twisted magnetic flux
tube filled with helical chaotic flows on the Riemann curvature tensor. When
Frenet torsion is positive, the Riemann curvature is unstable, while the
negative torsion induces an stability when time $t\to{\infty}$. This enhances
the dynamo action inside the MFTs. The Riemann metric, depends on the radial
random flows along the poloidal and toroidal directions. The Anosov flows has
been applied by Arnold, Zeldovich, Ruzmaikin and Sokoloff [\textbf{JETP
(1982)}] to build a uniformly stretched dynamo flow solution, based on Arnold's
Cat Map. It is easy to show that when the random radial flow vanishes, the
magnetic field vanishes, since the exponential Lyapunov stretches vanishes.
This is an example of the application of the Vishik's anti-fast dynamo theorem
in the magnetic flux tubes. Geodesic flows of both Arnold and twisted MFT
dynamos are investigated. It is shown that a constant random radial flow can be
obtained from the geodesic equation. Throughout the paper one assumes, the
reasonable plasma astrophysical hypothesis of the weak torsion. Pseudo-Anosov
dynamo flows and maps have also been addressed by Gilbert [\textbf{Proc Roy Soc
A London (1993)}


title:
Pion cloud and sea quark flavor asymmetry in the impact parameter
  representation

abstract:
  We study large-distance contributions to the nucleon parton densities in the
transverse coordinate (impact parameter) representation based on generalized
parton distributions (GPDs). Chiral dynamics generates a distinct component of
the partonic structure, located at momentum fractions x ~< M_pi/M_N and
transverse distances b ~ 1/M_pi. We analyze the phenomenological "pion cloud"
model of the flavor asymmetry dbar(x) - ubar(x) and quantify what fraction of
the calculated asymmetry results from the universal large-distance region. Our
findings indicate that a two-component picture of the nucleon's partonic
structure, with a "core" antiquark distribution at b < b_core ~= 0.55 fm which
vanishes at x -> 0 and the universal large-distance pion cloud, could naturally
account for the x-dependence of the measured asymmetry.


title: Influence of Dimensionality on Thermoelectric Device Performance

abstract:
  The role of dimensionality on the electronic performance of thermoelectric
devices is clarified using the Landauer formalism, which shows that the
thermoelectric coefficients are related to the transmission, T(E), and how the
conducing channels, M(E), are distributed in energy. The Landauer formalism
applies from the ballistic to diffusive limits and provides a clear way to
compare performance in different dimensions. It also provides a physical
interpretation of the "transport distribution," a quantity that arises in the
Boltzmann transport equation approach. Quantitative comparison of
thermoelectric coefficients in one, two, and three dimension shows that the
channels may be utilized more effectively in lower-dimensions. To realize the
advantage of lower dimensionality, however, the packing density must be very
high, so the thicknesses of the quantum wells or wires must be small. The
potential benefits of engineering M(E) into a delta-function are also
investigated. When compared to a bulk semiconductor, we find the potential for
~50 % improvement in performance. The shape of M(E) improves as dimensionality
decreases, but lower dimensionality itself does not guarantee better
performance because it is controlled by both the shape and the magnitude of
M(E). The benefits of engineering the shape of M(E) appear to be modest, but
approaches to increase the magnitude of M(E) could pay large dividends.


title:
Rapidly-Varying Speed of Sound, Scale Invariance and Non-Gaussian
  Signatures

abstract:
  We show that curvature perturbations acquire a scale invariant spectrum for
any constant equation of state, provided the fluid has a suitably
time-dependent sound speed. In order for modes to exit the physical horizon,
and in order to solve the usual problems of standard big bang cosmology, we
argue that the only allowed possibilities are inflationary (albeit not
necessarily slow-roll) expansion or ekpyrotic contraction. Non-Gaussianities
offer many distinguish features. As usual with a small sound speed,
non-Gaussianity can be relatively large, around current sensitivity levels. For
DBI-like lagrangians, the amplitude is negative in the inflationary branch, and
can be either negative or positive in the ekpyrotic branch. Unlike the power
spectrum, the three-point amplitude displays a large tilt that, in the
expanding case, peaks on smallest scales. While the shape is predominantly of
the equilateral type in the inflationary branch, as in DBI inflation, it is of
the local form in the ekpyrotic branch. The tensor spectrum is also generically
far from scale invariant. In the contracting case, for instance, tensors are
strongly blue tilted, resulting in an unmeasurably small gravity wave amplitude
on cosmic microwave background scales.


title:
Accurate Microwave Control and Real-Time Diagnostics of Neutral Atom
  Qubits

abstract:
  We demonstrate accurate single-qubit control in an ensemble of atomic qubits
trapped in an optical lattice. The qubits are driven with microwave radiation,
and their dynamics tracked by optical probe polarimetry. Real-time diagnostics
is crucial to minimize systematic errors and optimize the performance of
single-qubit gates, leading to fidelities of 0.99 for single-qubit pi
rotations. We show that increased robustness to large, deliberately introduced
errors can be achieved through the use of composite rotations. However, during
normal operation the combination of very small intrinsic errors and additional
decoherence during the longer pulse sequences precludes any significant
performance gain in our current experiment.


title:
Gravity with Perturbative Constraints: Dark Energy Without New Degrees
  of Freedom

abstract:
  Major observational efforts in the coming decade are designed to probe the
equation of state of dark energy. Measuring a deviation of the
equation-of-state parameter w from -1 would indicate a dark energy that cannot
be represented solely by a cosmological constant. While it is commonly assumed
that any implied modification to the LambdaCDM model amounts to the addition of
new dynamical fields, we propose here a framework for investigating whether or
not such new fields are required when cosmological observations are combined
with a set of minimal assumptions about the nature of gravitational physics. In
our approach, we treat the additional degrees of freedom as perturbatively
constrained and calculate a number of observable quantities, such as the Hubble
expansion rate and the cosmic acceleration, for a homogeneous Universe. We show
that current observations place our Universe within the perturbative validity
of our framework and allow for the presence of non-dynamical gravitational
degrees of freedom at cosmological scales.


title:
The Optical Gravitational Lensing Experiment. The OGLE-III Catalog of
  Variable Stars. II. Type II Cepheids and Anomalous Cepheids in the Large
  Magellanic Cloud

abstract:
  In the second part of the OGLE-III Catalog of Variable Stars (OIII-CVS) we
present 197 type II Cepheids and 83 anomalous Cepheids in the Large Magellanic
Cloud (LMC). The sample of type II Cepheids consists of 64 BL Her stars, 96 W
Vir stars and 37 RV Tau stars. Anomalous Cepheids are divided into 62
fundamental-mode and 21 first-overtone pulsators. These are the largest samples
of such types of variable stars detected anywhere outside the Galaxy.
  We present the period-luminosity and color-magnitude diagrams of stars in the
sample. If the boundary period between BL Her and W Vir stars is adopted at 4
days, both groups differ significantly in (V-I) colors. We identify a group of
16 peculiar W Vir stars with different appearance of the light curves, brighter
and bluer than ordinary stars of that type. Four of these peculiar W Vir stars
show additional eclipsing modulation superimposed on the pulsation light
curves. Four other stars of that type show long-period secondary variations
which may be ellipsoidal modulations. It suggests that peculiar W Vir subgroup
may be related to binarity. In total, we identified seven type II Cepheids
simultaneously exhibiting eclipsing variations which is a very large fraction
compared to classical Cepheids in the LMC. We discuss diagrams showing Fourier
parameters of the light curve decomposition against periods. Three sharp
features interpreted as an effect of resonances between radial modes are
detectable in these diagrams for type II Cepheids.


title:
Two soliton solutions to the three dimensional gravitational Hartree
  equation

abstract:
  We construct non dispersive two soliton solutions to the three dimensional
gravitational Hartree equation whose trajectories asymptotically reproduce the
nontrapped dynamics of the gravitational two body problem.


title:
Three-Dimensional Relativistic MHD Simulations of the Kelvin-Helmholtz
  Instability: Magnetic Field Amplification by a Turbulent Dynamo

abstract:
  Magnetic field strengths inferred for relativistic outflows including
gamma-ray bursts (GRB) and active galactic nuclei (AGN) are larger than naively
expected by orders of magnitude. We present three-dimensional relativistic
magnetohydrodynamics (MHD) simulations demonstrating amplification and
saturation of magnetic field by a macroscopic turbulent dynamo triggered by the
Kelvin-Helmholtz shear instability. We find rapid growth of electromagnetic
energy due to the stretching and folding of field lines in the turbulent
velocity field resulting from non-linear development of the instability. Using
conditions relevant for GRB internal shocks and late phases of GRB afterglow,
we obtain amplification of the electromagnetic energy fraction to $\epsilon_B
\sim 5 \times 10^{-3}$. This value decays slowly after the shear is dissipated
and appears to be largely independent of the initial field strength. The
conditions required for operation of the dynamo are the presence of velocity
shear and some seed magnetization both of which are expected to be commonplace.
We also find that the turbulent kinetic energy spectrum for the case studied
obeys Kolmogorov's 5/3 law and that the electromagnetic energy spectrum is
essentially flat with the bulk of the electromagnetic energy at small scales.


title: Zero-state Markov switching count-data models: an empirical assessment

abstract:
  In this study, a two-state Markov switching count-data model is proposed as
an alternative to zero-inflated models to account for the preponderance of
zeros sometimes observed in transportation count data, such as the number of
accidents occurring on a roadway segment over some period of time. For this
accident-frequency case, zero-inflated models assume the existence of two
states: one of the states is a zero-accident count state, in which accident
probabilities are so low that they cannot be statistically distinguished from
zero, and the other state is a normal count state, in which counts can be
non-negative integers that are generated by some counting process, for example,
a Poisson or negative binomial. In contrast to zero-inflated models, Markov
switching models allow specific roadway segments to switch between the two
states over time. An important advantage of this Markov switching approach is
that it allows for the direct statistical estimation of the specific
roadway-segment state (i.e., zero or count state) whereas traditional
zero-inflated models do not. To demonstrate the applicability of this approach,
a two-state Markov switching negative binomial model (estimated with Bayesian
inference) and standard zero-inflated negative binomial models are estimated
using five-year accident frequencies on Indiana interstate highway segments. It
is shown that the Markov switching model is a viable alternative and results in
a superior statistical fit relative to the zero-inflated models.


title:
The B -> pi l nu semileptonic form factor from three-flavor lattice QCD:
  A model-independent determination of |V(ub)|

abstract:
  We calculate the form factor f_+(q^2) for B-meson semileptonic decay in
unquenched lattice QCD with 2+1 flavors of light sea quarks. We use
Asqtad-improved staggered light quarks and a Fermilab bottom quark on gauge
configurations generated by the MILC Collaboration. We simulate with several
light quark masses and at two lattice spacings, and extrapolate to the physical
quark mass and continuum limit using heavy-light meson staggered chiral
perturbation theory. We then fit the lattice result for f_+(q^2) simultaneously
with that measured by the BABAR experiment using a parameterization of the form
factor shape in q^2 which relies only on analyticity and unitarity in order to
determine the CKM matrix element |V(ub)|. This approach reduces the total
uncertainty in |V(ub)| by combining the lattice and experimental information in
an optimal, model-independent manner. We find a value of |V(ub)| x 10^3 = 3.38
+/- 0.36.


title:
The Case for a 700+ GeV WIMP: Cosmic Ray Spectra from PAMELA, Fermi and
  ATIC

abstract:
  Multiple lines of evidence indicate an anomalous injection of high-energy e+-
in the Galactic halo. The recent $e^+$ fraction spectrum from the Payload for
Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) shows a
sharp rise up to 100 GeV. The Fermi Gamma-ray Space Telescope has found a
significant hardening of the e+e- cosmic ray spectrum above 100 GeV, with a
break, confirmed by HESS at around 1 TeV. The Advanced Thin Ionization
Calorimeter (ATIC) has also detected detected a similar excess, falling back to
the expected spectrum at 1 TeV and above. Excess microwaves towards the
galactic center in the WMAP data are consistent with hard synchrotron radiation
from a population of 10-100 GeV e+- (the WMAP ``Haze''). We argue that dark
matter annihilations can provide a consistent explanation of all of these data,
focusing on dominantly leptonic modes, either directly or through a new light
boson. Normalizing the signal to the highest energy evidence (Fermi and HESS),
we find that similar cross sections provide good fits to PAMELA and the Haze,
and that both the required cross section and annihilation modes are achievable
in models with Sommerfeld-enhanced annihilation. These models naturally predict
significant production of gamma rays in the galactic center via a variety of
mechanisms. Most notably, there is a robust inverse-Compton scattered (ICS)
gamma-ray signal arising from the energetic electrons and positrons, detectable
at Fermi/GLAST energies, which should provide smoking gun evidence for this
production.


title: NLO Evolution of Color Dipoles in N = 4 SYM

abstract:
  The small-$x_B$ deep inelastic scattering in the saturation region is
governed by the non-linear evolution of Wilson-line operators. In the leading
logarithmic approximation it is given by the BK equation for the evolution of
color dipoles. I discuss recent calculation of the next-to-leading order
evolution of color dipoles in QCD and ${\cal N}=4$ SYM.


title:
Internal space structure generalization of the quintom cosmological
  scenario

abstract:
  We introduce the Lagrangian for a multi-scalar field configuration in a
$N$-dimensional internal space endowed with a constant metric $Q_{ik}$ and
generalize the quintom cosmological scenario. We find the energy momentum
tensor of the model and show that the set of dual transformations, that
preserve the form of the Einstein equations in the Friedmann-Robertson-Walker
(FRW) cosmology, is enlarged. We show that the stability of the power law
solutions leads to an exponential potential which is invariant under linear
transformations in the internal space. Moreover, we obtain the general exact
solution of the Einstein-Klein-Gordon equations for that potential. There exist
solutions that cross the phantom divide and solutions that blow up at a finite
time, exhibiting a superaccelerated behavior and ending in a big rip. We show
that the quintom model with a separable potential can be identified with a
mixture of several fluids. This framework includes the $\Lambda$CDM model, a
bouncing model, and a setting sourced by a cosmic string network plus a
cosmological constant. The we concentrate on the case where the dimension of
the internal quintessence sector $N_{q}$ exceeds the dimension of the internal
phantom sector $N_{ph}$. For $(N_q,N_{ph})=(2,1)$ the dark energy density
derived from the 3-scalar field crosses the phantom divide and its negative
component plays the role of the negative part of a classical Dirac Field.


title:
Markov switching multinomial logit model: an application to accident
  injury severities

abstract:
  In this study, two-state Markov switching multinomial logit models are
proposed for statistical modeling of accident injury severities. These models
assume Markov switching in time between two unobserved states of roadway
safety. The states are distinct, in the sense that in different states accident
severity outcomes are generated by separate multinomial logit processes. To
demonstrate the applicability of the approach presented herein, two-state
Markov switching multinomial logit models are estimated for severity outcomes
of accidents occurring on Indiana roads over a four-year time interval.
Bayesian inference methods and Markov Chain Monte Carlo (MCMC) simulations are
used for model estimation. The estimated Markov switching models result in a
superior statistical fit relative to the standard (single-state) multinomial
logit models. It is found that the more frequent state of roadway safety is
correlated with better weather conditions. The less frequent state is found to
be correlated with adverse weather conditions.


title: Discontinuities at the DNA supercoiling transition

abstract:
  While slowly turning the ends of a single molecule of DNA at constant applied
force, a discontinuity was recently observed at the supercoiling transition,
when a small plectoneme is suddenly formed. This can be understood as an abrupt
transition into a state in which stretched and plectonemic DNA coexist. We
argue that there should be discontinuities in both the extension and the torque
at the transition, and provide experimental evidence for both. To predict the
sizes of these discontinuities and how they change with the overall length of
DNA, we organize a theory for the coexisting plectonemic state in terms of four
length-independent parameters. We also test plectoneme theories, including our
own elastic rod simulation, finding discrepancies with experiment that can be
understood in terms of the four coexisting state parameters.


title: On the geometry of string duals with backreacting flavors

abstract:
  Making use of generalized calibrated geometry and G-structures we put the
problem of finding string-duals with smeared backreacting flavor branes in a
more mathematical setting. This more formal treatment of the problem allows us
to easily smear branes without good coordinate representations, establish
constraints on the smearing form and identify a topological central charge in
the SUSY algebra. After exhibiting our methods for a series of well known
examples, we apply them to the problem of flavoring a supergravity-dual to a
d=2+1 dimensional N=2 super Yang-Mills-like theory. We find new solutions to
both the flavored and unflavored systems. Interpretating these turns out to be
difficult.


title:
Upper critical field study in the organic superconductor
  $\beta''$-(ET)$_{2}$SF$_{5}$CH$_{2}$CF$_{2}$SO$_{3}$ : Possibility of
  Fulde-Ferrell-Larkin-Ovchinnikov state

abstract:
  We report upper critical field measurements in the metal-free-all-organic
superconductor $\beta''$-(ET)$_{2}$SF$_{5}$CH$_{2}$CF$_{2}$SO$_{3}$ obtained
from measuring the in-plane penetration depth using the tunnel diode oscillator
technique. For magnetic field applied parallel to the conducting planes the low
temperature upper critical fields are found to exceed the Pauli limiting field
calculated by using a semi-empirical method. Furthermore, we found a signature
that could be the phase transition between the superconducting vortex state and
the Fulde-Ferrell-Larkin-Ovchinnikov state in the form of a kink just below the
upper critical field and only at temperatures below 1.23 K.


title: Revisiting Norm Estimation in Data Streams

abstract:
  The problem of estimating the pth moment F_p (p nonnegative and real) in data
streams is as follows. There is a vector x which starts at 0, and many updates
of the form x_i <-- x_i + v come sequentially in a stream. The algorithm also
receives an error parameter 0 < eps < 1. The goal is then to output an
approximation with relative error at most eps to F_p = ||x||_p^p.
  Previously, it was known that polylogarithmic space (in the vector length n)
was achievable if and only if p <= 2. We make several new contributions in this
regime, including:
  (*) An optimal space algorithm for 0 < p < 2, which, unlike previous
algorithms which had optimal dependence on 1/eps but sub-optimal dependence on
n, does not rely on a generic pseudorandom generator.
  (*) A near-optimal space algorithm for p = 0 with optimal update and query
time.
  (*) A near-optimal space algorithm for the "distinct elements" problem (p = 0
and all updates have v = 1) with optimal update and query time.
  (*) Improved L_2 --> L_2 dimensionality reduction in a stream.
  (*) New 1-pass lower bounds to show optimality and near-optimality of our
algorithms, as well as of some previous algorithms (the "AMS sketch" for p = 2,
and the L_1-difference algorithm of Feigenbaum et al.).
  As corollaries of our work, we also obtain a few separations in the
complexity of moment estimation problems: F_0 in 1 pass vs. 2 passes, p = 0 vs.
p > 0, and F_0 with strictly positive updates vs. arbitrary updates.


title:
Traces of high powers of the Frobenius class in the hyperelliptic
  ensemble

abstract:
  The zeta function of a curve over a finite field may be expressed in terms of
the characteristic polynomial of a unitary symplectic matrix, called the
Frobenius class of the curve. We compute the expected value of the trace of the
n-th power of the Frobenius class for an ensemble of hyperelliptic curves of
genus g over a fixed finite field in the limit of large genus, and compare the
results to the corresponding averages over the unitary symplectic group
USp(2g). We are able to compute the averages for powers n almost up to 4g,
finding agreement with the Random Matrix results except for small n and for
n=2g. As an application we compute the one-level density of zeros of the zeta
function of the curves, including lower-order terms, for test functions whose
Fourier transform is supported in (-2,2). The results confirm in part a
conjecture of Katz and Sarnak, that to leading order the low-lying zeros for
this ensemble have symplectic statistics.


title: Isoperimetric problems on time scales with nabla derivatives

abstract:
  We prove a necessary optimality condition for isoperimetric problems under
nabla-differentiable curves. As a consequence, the recent results of [M.R.
Caputo, A unified view of ostensibly disparate isoperimetric variational
problems, Appl. Math. Lett. (2008), doi:10.1016/j.aml.2008.04.004], that put
together seemingly dissimilar optimal control problems in economics and
physics, are extended to a generic time scale. We end with an illustrative
example of application of our main result to a dynamic optimization problem
from economics.


title:
Influence of higher-order harmonics on the saturation of the tearing
  mode

abstract:
  The nonlinear saturation of the tearing mode is revisited in slab geometry by
taking into account higher-order harmonics in the outer solution. The general
formalism for tackling this problem in the case of a vanishing current gradient
at the resonant surface is derived. It is shown that, although the higher-order
harmonics lead to corrections in the final saturation equation, they are of
higher order in the perturbation parameter, which provides a formal proof that
the standard one-harmonic approach is asymptotically correct.


title: Polynomial Coefficient Enumeration

abstract:
  Let $f(x_1,...,x_k)$ be a polynomial over a field $K$. This paper considers
such questions as the enumeration of the number of nonzero coefficients of $f$
or of the number of coefficients equal to $\alpha\in K^*$. For instance, if
$K=\ff_q$ then a matrix formula is obtained for the number of coefficients of
$f^n$ that are equal to $\alpha\in \ff_q^*$, as a function of $n$. Many
additional results are obtained related to such areas as lattice path
enumeration and the enumeration of integer points in convex polytopes.


title: A Fundamentally New Perspective on the Origin and Evolution of Life

abstract:
  Darwin's hypothesis that all extant life forms are descendants of a last
common ancestor cell and diversification of life forms results from gradual
mutation plus natural selection represents a mainstream view that has
influenced biology and even society for over a century. However, this Darwinian
view on life is contradicted by many observations and lacks a plausible
physico-chemical explanation. Strong evidence suggests that the common ancestor
cell hypothesis is the most fundamental flaw of Darwinism. By contrast, a
totally different perspective on origin and evolution of life claims that
cellular life forms were descendants of already diversified acellular life
forms. Independently originated life forms evolve largely in some parallel ways
even though they also interact with each other. Some evolutionary "gaps"
naturally exist among evolutionary lines. Similarity may not be the only result
of phylogenetic inheritance but may be a result of a convergent mechanism of
origin and evolution. Evolution is not a random process but follows some basic
physico-chemical principles as a result of the interplay of both energy and
entropy on matter.


title:
Chandra observations of the galaxy group AWM 5: cool core re-heating and
  thermal conduction suppression

abstract:
  We present an analysis of a 40 ksec Chandra observation of the galaxy group
AWM 5. It has a small ($\sim8$ kpc) dense cool core with a temperature of
$\sim1.2$ keV and the temperature profile decreases at larger radii, from
$\sim3.5$ keV just outside the core to $\sim2$ keV at $\sim300$ kpc from the
center. The abundance distribution shows a "hole" in the central $\sim10$ kpc,
where the temperature declines sharply. An abundance of at least a few times
solar is observed $\sim15-20$ kpc from the center. The deprojected electron
density profile shows a break in slope at $\sim13$ kpc and can be fit by two
$\beta$-models, with $\beta=0.72_{-0.11}^{+0.16}$ and $r_c=5.7_{-1.5}^{+1.8}$
kpc, for the inner part, and $\beta=0.34\pm0.01$ and $r_c=31.3_{-5.5}^{+5.8}$
kpc, for the outer part. The mass fraction of hot gas is fairly flat in the
center and increases for $r>30$ kpc up to a maximum of $\sim6.5%$ at $r\sim380$
kpc. The gas cooling time within the central 30 kpc is smaller than a Hubble
time, although the temperature only declines in the central $\sim8$ kpc region.
This discrepancy suggests that an existing cooling core has been partially
re-heated. In particular, thermal conduction could have been a significant
source of re-heating. In order for heating due to conduction to balance cooling
due to emission of X-rays, the conductivity must be suppressed by a large
factor (at least $\sim100$). Past AGN activity (still visible as a radio source
in the center of the group) is however the most likely source that re-heated
the central regions of AWM 5.


title: A generalization of the Strong Castelnuovo Lemma

abstract:
  We consider a set $X$ of distinct points in the $n$-dimensional projective
space over an algebraically closed field $k$. Let $A$ denote the coordinate
ring of $X$, and let $a_i(X)=\dim_k [{\rm Tor}_i^R(A,k)]_{i+1}$. Green's Strong
Castelnuovo Lemma (SCL) shows that if the points are in general position, then
$a_{n-1}(X)\neq 0$ if and only if the points are on a rational normal curve.
Cavaliere, Rossi and Valla conjectured that if the points are not necessarily
in general position the possible extension of the SCL should be the following:
$a_{n-1}(X)\neq 0$ if and only if either the points are on a rational normal
curve or in the union of two linear subspaces whose dimensions add up to $n$.
In this work we prove the conjecture.


title: Ferrotoroidic Moment as a Quantum Geometric Phase

abstract:
  We present a geometric characterization of the ferrotoroidic moment in terms
of a set of Abelian Berry phases. We also introduce a fundamental complex
quantity which provides an alternative way to calculate the ferrotoroidic
moment and its moments, and is derived from a second order tensor. This
geometric framework defines a natural computational approach for density
functional and many-body theories.


title: General Mechanisms for Inverted Biomass Pyramids in Ecosystems

abstract:
  Although the existence of robust inverted biomass pyramids seem paradoxical,
they have been observed in planktonic communities, and more recently, in
pristine coral reefs. Understanding the underlying mechanisms which produce
inverted biomass pyramids provides new ecological insights, and for coral
reefs, may help mitigate or restore damaged reefs. We present three classes of
predator-prey models which elucidate mechanisms that generate robust inverted
biomass pyramids. The first class of models exploits well-mixing of predators
and prey, the second class has a refuge (with explicit size) for the prey to
hide, and the third class incorporates the immigration of prey. Our models
indicate that inverted biomass pyramids occur when the prey growth rate, prey
carrying capacity, biomass conversion efficiency, the predator life span, or
the immigration rate of prey fish is sufficiently large. In the second class,
we discuss three hypotheses on how refuge size can impact the amount of prey
available to predators. By explicitly incorporating a refuge size, these can
more realistically model predator-prey interactions than refgue models with
implicit refuge size.


title:
Quantum phase transitions in a two-dimensional quantum XYX model:
  Ground-state fidelity and entanglement

abstract:
  A systematic analysis is performed for quantum phase transitions in a
two-dimensional anisotropic spin 1/2 anti-ferromagnetic XYX model in an
external magnetic field. With the help of an innovative tensor network
algorithm, we compute the fidelity per lattice site to demonstrate that the
field-induced quantum phase transition is unambiguously characterized by a
pinch point on the fidelity surface, marking a continuous phase transition. We
also compute an entanglement estimator, defined as a ratio between the
one-tangle and the sum of squared concurrences, to identify both the
factorizing field and the critical point, resulting in a quantitative agreement
with quantum Monte Carlo simulation. In addition, the local order parameter is
"derived" from the tensor network representation of the system's ground state
wave functions.


title: Computational Biomechanics, Stochastic Motion and Team Sports

abstract:
  The objective of the present study is to present a computational model of the
motion of a single athlete in a team and to compare the resulting trajectory
with experimental data obtained in the field during competitions by match
analysis software. To this purpose, some results related to a paths ensemble of
a single player are discussed. Between each interaction it is assumed that he
follows a straight line and his motion is characterized by viscous, pushing and
pedestrian like force. A random force is supposed to influence only the
trajectory direction after each interaction. Furthermore it is assumed that the
time step between each interaction is a random variable belonging to a Gaussian
distribution. The main criteria is a selection of a function correlated to the
strategy of the player, around which, in a necessarily randomly way, a tactic
function should be added. The strategy depends on the players role: for the
numerical simulations in this paper, a forward player was selected, with the
average target to score. So it is straightforward to assume that the line
direction joining the player position and a point related to the goal, would be
the main strategy objective function around which a random angle A rand,
expression of the tactic objective function, influencing the direction selected
by the player until a next interaction could be introduced. The comparison
between both single and multiple experimental paths and figures obtained by the
numerical methodology proposed in this paper are very interesting, showing
common Brownian path structures.


title: The Consumption of Reference Resources

abstract:
  Under the operational restriction of the U(1)-superselection rule, states
that contain coherences between eigenstates of particle number constitute a
resource. Such resources can be used to facilitate operations upon systems that
otherwise cannot be performed. However, the process of doing this consumes
reference resources. We show this explicitly for an example of a unitary
operation that is forbidden by the U(1)-superselection rule.


title: Weakly infinite dimensional subsets of R^N

abstract:
  The Continuum Hypothesis implies an Erd\"os-Sierpi\'nski like duality between
the ideal of first category subsets of $\reals^{\naturals}$, and the ideal of
countable dimensional subsets of $\reals^{\naturals}$. The algebraic sum of a
Hurewicz subset - a dimension theoretic analogue of Sierpinski sets and Lusin
sets - of $\reals^{\naturals}$ with any compactly countable dimensional subset
of $\reals^{\naturals}$ has first category.


title: Low-mass lepton pair production at large transverse momentum

abstract:
  We study the transverse momentum distribution of low-mass lepton pairs
produced in hadronic scattering, using the perturbative QCD factorization
approach. We argue that the distribution at large transverse momentum, $Q_T \gg
Q$, with the pair's invariant mass $Q$ as low as $Q \sim
\Lambda_{\mathrm{QCD}}$, can be systematically factorized into universal
parton-to-lepton pair fragmentation functions, parton distributions, and
perturbatively calculable partonic hard parts evaluated at a short distance
scale $\sim {\cal O}(1/Q_T)$. We introduce a model for the input lepton pair
fragmentation functions at a scale $\mu_0\sim 1$ GeV, which are then evolved
perturbatively to scales relevant at RHIC. Using the evolved fragmentation
functions, we calculate the transverse momentum distributions in hadron-hadron,
hadron-nucleus, and nucleus-nucleus collisions at RHIC. We also discuss the
sensitivity of the transverse momentum distribution of low-mass lepton pairs to
the gluon distribution.


title: On a Diophantine problem with two primes and s powers of two

abstract:
  We refine a recent result of Parsell on the values of the form $\lambda_1p_1
+ \lambda_2p_2 + \mu_1 2^{m_1} + ...m + \mu_s 2^{m_s}, $ where $p_1,p_2$ are
prime numbers, $m_1,...c, m_s$ are positive integers, $\lambda_1 / \lambda_2$
is negative and irrational and $\lambda_1 / \mu_1$, $\lambda_2/\mu_2 \in \Q$.


title:
Dynamics of postcritically bounded polynomial semigroups I: connected
  components of the Julia sets

abstract:
  We investigate the dynamics of semigroups generated by a family of polynomial
maps on the Riemann sphere such that the postcritical set in the complex plane
is bounded. The Julia set of such a semigroup may not be connected in general.
We show that for such a polynomial semigroup, if $A$ and $B$ are two connected
components of the Julia set, then one of $A$ and $B$ surrounds the other. From
this, it is shown that each connected component of the Fatou set is either
simply or doubly connected. Moreover, we show that the Julia set of such a
semigroup is uniformly perfect. An upper estimate of the cardinality of the set
of all connected components of the Julia set of such a semigroup is given. By
using this, we give a criterion for the Julia set to be connected. Moreover, we
show that for any $n\in \Bbb{N} \cup \{\aleph_{0}\} ,$ there exists a finitely
generated polynomial semigroup with bounded planar postcritical set such that
the cardinality of the set of all connected components of the Julia set is
equal to $n.$ Many new phenomena of polynomial semigroups that do not occur in
the usual dynamics of polynomials are found and systematically investigated.


title:
Time-dependent Dalitz Plot Measurement of CP Parameters in B0 --> Ks Pi+
  Pi- Decays

abstract:
  We present a time-dependent Dalitz plot measurement of CP violation
parameters in B0 --> Ks Pi+ Pi- decays. These results are obtained from a large
data sample that contains 657 million BBbar pairs collected at the Y(4S)
resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider.
For the CP violation parameters, we obtain two consistent solutions that
describe the data well. The first of these solutions may be preferred by
external information from other measurements. There is no evidence for direct
CP violation in B0 --> rho0(770) Ks, B0 --> f0(980) Ks and B0 --> K*+(892) Pi-,
while measurements of mixing-induced CP violation in B0 --> rho0(770) Ks, B0
--> f0(980) Ks decays are consistent with that of b --> c cbar s decays. We
also measured the phase difference between B0 --> K*+(892) Pi- and B0B -->
K*-(892) Pi+ which may be used to extract phi3.


title: A characteristic subgroup for fusion systems

abstract:
  As a counterpart for the prime 2 to Glauberman's $ZJ$-theorem, Stellmacher
proves that any nontrivial 2-group $S$ has a nontrivial characteristic subgroup
$W(S)$ with the following property. For any finite $\Sigma_4$-free group $G$,
with $S$ a Sylow 2-subgroup of $G$ and with $O_2(G)$ self-centralizing, the
subgroup $W(S)$ is normal in $G$. We generalize Stellmacher's result to fusion
systems. A similar construction of $W(S)$ can be done for odd primes and gives
rise to a Glauberman functor.


title:
Constraints on effective constitutive parameters of certain
  bianisotropic laminated composite materials

abstract:
  When the electrically thin unit cell of a laminated composite material is
made of two bianisotropic sheets whose constitutive properties in the thickness
direction are decoupled from the constitutive properties in the interfacial
planes, the laminated composite material can be homogenized into a material not
all of whose constitutive parameters are independent of each other. This
non-independence of the constitutive dyadics of the constituent materials and
the homogenized composite material is captured by two simple constraints, which
may not hold if even one of the two constituent materials has more complicated
constitutive properties than stated above.


title: On the conformally coupled scalar field quantum cosmology

abstract:
  We propose a new initial condition for the homogeneous and isotropic quantum
cosmology, where the source of the gravitational field is a conformally coupled
scalar field, and the maximally symmetric hypersurfaces have positive
curvature. After solving corresponding Wheeler-DeWitt equation, we obtain exact
solutions in both classical and quantum levels. We propose appropriate initial
condition for the wave packets which results in a complete classical and
quantum correspondence. These wave packets closely follow the classical
trajectories and peak on them. We also quantify this correspondence using
de-Broglie Bohm interpretation of quantum mechanics. Using this proposal, the
quantum potential vanishes along the Bohmian paths and the classical and
Bohmian trajectories coincide with each other. We show that the model contains
singularities even at the quantum level. Therefore, the resulting wave packets
closely follow the classical trajectories from big-bang to big-crunch.


title: Lower Critical Fields of Superconducting PrFeAsO$_{1-y}$ Single Crystals

abstract:
  We have studied the lower critical fields H_{c1} of superconducting iron
oxipnictide PrFeAsO_{1-y} single crystals for H parallel and perpendicular to
the ab-planes. Measurements of the local magnetic induction at positions
straddling the sample edge by using a miniature Hall-sensor array clearly
resolve the first flux penetration from the Meissner state. The temperature
dependence of H_{c1} for H || c is well scaled by the in-plane penetration
depth without showing any unusual behavior, in contrast to previous reports.
The anisotropy of penetration lengths at low temperatures is estimated to be ~
2.5, which is much smaller than the anisotropy of the coherence lengths. This
is indicative of multiband superconductivity in this system, in which the
active band for superconductivity is more anisotropic. We also point out that
the local induction measured at a position near the center of the crystal,
which has been used in a number of reports for the determination of H_{c1},
might seriously overestimate the obtained H_{c1}-value.


title: An Arena for Model Building in the Cohen-Glashow Very Special Relativity

abstract:
  The Cohen-Glashow Very Special Relativity (VSR) algebra
[arXiv:hep-ph/0601236] is defined as the part of the Lorentz algebra which upon
addition of CP or T invariance enhances to the full Lorentz group, plus the
space-time translations. We show that noncommutative space-time, in particular
noncommutative Moyal plane, with light-like noncommutativity provides a robust
mathematical setting for quantum field theories which are VSR invariant and
hence set the stage for building VSR invariant particle physics models. In our
setting the VSR invariant theories are specified with a single deformation
parameter, the noncommutativity scale \Lambda_{NC}. Preliminary analysis with
the available data leads to \Lambda_{NC}\gtrsim 1-10 TeV.
  This note is prepared for the Proceedings of the G27 Mathematical Physics
Conference, Yerevan 2008, and is based on arXiv:0806.3699[hep-th].


title:
Nonlinear dynamics of soft fermion excitations in hot QCD plasma III:
  Soft-quark bremsstrahlung and energy losses

abstract:
  In general line with our early works [Yu.A. Markov, M.A. Markova, Nucl. Phys.
A770 (2006) 162; 784 (2007) 443] within the framework of a semiclassical
approximation the general theory of calculation of effective currents and
sources generating bremsstrahlung of an arbitrary number of soft quarks and
soft gluons at collision of a high-energy color-charged particle with thermal
partons in a hot quark-gluon plasma, is developed. For the case of one- and
two-scattering thermal partons with radiation of one or two soft excitations,
the effective currents and sources are calculated in an explicit form. In the
model case of `frozen' medium, approximate expressions for energy losses
induced by the most simple processes of bremsstrahlung of soft quark and soft
gluon, are derived. On the basis of a conception of the mutual cancellation of
singularities in the sum of so-called `diagonal' and `off-diagonal'
contributions to the energy losses, an effective method of determining color
factors in scattering probabilities, containing the initial values of Grassmann
color charges, is suggested. The dynamical equations for Grassmann color
charges of hard particle used by us early are proved to be insufficient for
investigation of the higher radiative processes. It is shown that for correct
description of these processes the given equations should be supplemented
successively with the higher-order terms in powers of the soft fermionic field.


title: 75As-NMR studies on La FeAsO1-xFx (x=0.14) under a pressure of 3GPa

abstract:
  75As-nuclear magnetic resonance (NMR) on an iron-based superconductor
LaFeAsO1-xFx (x=0.14) was performed under a pressure of 3GPa. Enhancement of
superconducting transition temperature Tc was confirmed from the relaxation
rate 1/T1; Tc goes up to 40K by applying pressure up to 3GPa. 1/T1T, which is
temperature independent just above Tc and gives a measure of the density of
states (DOS) at the Fermi energy, enhances by applying pressure. These facts
suggest that the increase of the DOS leads to the enhancement of Tc. On the
other hand, anomalous behavior of 1/T1T observed at high temperatures is
suppressed by applying pressure.


title: A simple theory of the Invar effect in iron-nickel alloys

abstract:
  Certain alloys of iron and nickel (so-called 'Invar' alloys) exhibit almost
no thermal expansion over a wide range of temperature. It is clear that this is
the result of an anomalous contraction upon heating which counteracts the
normal thermal expansion arising from the anharmonicity of lattice vibrations.
This anomalous contraction seems to be related to the alloys' magnetic
properties, since the effect vanishes at a temperature close to the Curie
temperature. However, despite many years of intensive research, a widely
accepted microscopic theory of the Invar effect in face-centered-cubic Fe-Ni
alloys is still lacking. Here we present a simple theory of the Invar effect in
these alloys based on Ising magnetism, ab initio total energy calculations, and
the Debye-Gruneisen model. We show that this theory accurately reproduces
several well known properties of these materials, including Guillaume's famous
plot1 of the thermal expansion coefficient as a function of the concentration
of nickel. Within the same framework, we are able to account in a
straightforward way for experimentally observed deviations from Vegard's law.
Our approach supports the idea that the lattice constant is governed by a few
parameters, including the fraction of iron-iron nearest-neighbour pairs.


title:
Quantum Correlations in Multipartite States. Study Based on the
  Wootters-Mermin Theorem

abstract:
  Decomposition of any N-partite state (density operator) into clusters (that
do not overlap) is studied in detail with a view to learn as much as possible
about the correlations implied by the state. The Wootters-Mermin theorem,
stating that the totality of all strings of cluster events (projectors)
determines the state in any finite- or infinite-dimensional state space, is a
slightly sharpened and generalized form of the original results of Wootters and
Mermin. It is applied to tensor factorization of the state into states of
clusters (uncorrelated decomposition) and it is shown that a finest
uncorrelated decomposition always exists, and that its coarsenings and only
they are other possible uncorrelated cluster decompositions. Distant effects
witin homogeneous cluster states, which are, by definition, the tensor factors
in the finest uncorrelated decomposition, are discussed. The entire study is
viewed by the author as a possible further elaboration of Mermin's Ithaca
program.