title: Photon Splitting and Pair Conversion in Strong Magnetic Fields

abstract:
  The magnetospheres of neutron stars provide a valuable testing ground for
as-yet unverified theoretical predictions of quantum electrodynamics (QED) in
strong electromagnetic fields. Exhibiting magnetic field strengths well in
excess of a TeraGauss, such compact astrophysical environments permit the
action of exotic mechanisms that are forbidden by symmetries in field-free
regions. Foremost among these processes are single-photon pair creation, where
a photon converts to an electron-positron pair, and magnetic photon splitting,
where a single photon divides into two of lesser energy via the coupling to the
external field. The pair conversion process is exponentially small in weak
fields, and provides the leading order contribution to vacuum polarization. In
contrast, photon splitting possesses no energy threshold and can operate in
kinematic regimes where the lower order pair conversion is energetically
forbidden. This paper outlines some of the key physical aspects of these
processes, and highlights their manifestation in neutron star magnetospheres.
Anticipated observational signatures include profound absorption turnovers in
pulsar spectra at gamma-ray wavelengths. The shapes of these turnovers provide
diagnostics on the possible action of pair creation and the geometrical locale
of the photon emission region. There is real potential for the first
confirmation of strong field QED with the new GLAST mission, to be launched by
NASA in 2008. Suppression of pair creation by photon splitting and its
implications for pulsars is also discussed.


title: On Generating Gravity Waves with Matter and Electromagnetic Waves

abstract:
  If a homogeneous plane light-like shell collides head-on with a homogeneous
plane electromagnetic shock wave having a step-function profile then no
backscattered gravitational waves are produced. We demonstrate, by explicit
calculation, that if the matter is accompanied by a homogeneous plane
electromagnetic shock wave with a step-function profile then backscattered
gravitational waves appear after the collision.


title: q-Analogue of Gauss' Divisibility Theorem

abstract: We give a q-analogue of Gauss' divisibility theorem


title:
Superconductivity at 36 K in Gadolinium-arsenide Oxides
  GdO$_{1-x}$F$_{x}$FeAs

abstract:
  In this paper we report the fabrication and superconducting properties of
GdO$_{1-x}$F$_{x}$FeAs. It is found that when x is equal to 0.17,
GdO$_{0.83}$F$_{0.17}$FeAs is a superconductor with the onset transition
temperature T$_{c}^{on}\approx$ 36.6K. Resistivity anomaly near 130K was
observed for all samples up to x = 0.17, such a phenomenon is similar to that
of LaO$_{1-x}$F$_{x}$FeAs. Hall coefficient indicates that
GdO$_{0.83}$F$_{0.17}$FeAs is conducted by electron-like charge carriers.


title: Light nuclei without a core

abstract:
  We introduce the no-core full configuration (NCFC) approach and present
results for $^4$He, $^{12}$C and $^{14}$F with the realistic NN interaction,
JISP16. We obtain ground state energies and their uncertainties through
exponential extrapolations that we demonstrate are reliable in $^4$He where
fully converged results are obtained. We find $^{12}$C is overbound by 1.7 MeV
and we predict the yet-to-be-measured binding energy of $^{14}$F to be $68.1
\pm 2.7$ MeV. The extrapolated spectrum of $^{14}$F is in reasonable agreement
with known features of the $^{14}$B spectrum.


title: Integrable Isotropic Geometrical Flows and Heisenberg Ferromagnets

abstract:
  Geometrical flows (GF) play an important role in modern mathematics and
physics. In this letter we have considered some integrable isotropic GF --
Ricci flows (RF) and mean curvature flows (MCF) -- which are related with
integrable Heisenberg ferromagnets. In 2+1 dimensions, these GF have a
singularity at $t=t_{0}$.


title:
Optimal axonal and dendritic branching strategies during the development
  of neural circuitry

abstract:
  In developing brain, axons and dendrites are capable of connecting to each
other with high precision. Recent advances in imaging have allowed for the
monitoring of axonal, dendritic, and synapse dynamics in vivo. It is observed
that the majority of axonal and dendritic branches are formed 'in error', only
to be retracted later. The functional significance of the overproduction of
branches is not clear. In this study, we use a computational model to
investigate the speed and efficiency of different branching strategies. We show
that branching itself allows for substantial acceleration in the identification
of appropriate targets through the use of a parallel search. We also show that
the formation of new branches in the vicinity of existing synapses leads to the
formation of target connectivity with a decreased number of erroneous branches.
This finding allows us to explain the high correlation between the branch
points and synapses observed in the Xenopus laevis retinotectal system. We also
suggest that the most efficient branching rule is different for axons and
dendrites. The optimal axonal strategy is to form new branches in the vicinity
of existing synapses, whereas the optimal rule for dendrites is to form new
branches preferentially in the vicinity of synapses with correlated pre- and
postsynaptic electric activity. Thus, our studies suggest that the developing
neural system employs a set of sophisticated computational strategies that
facilitate the formation of required circuitry, so that it may proceed in the
fastest and most frugal way.


title:
The eclipsing LMC star OGLE05155332--6925581: a clue for Double Periodic
  Variables

abstract:
  We investigate the nature of OGLE05155332-6925581, one of the brightest
members of the enigmatic group of Double Periodic Variables (DPVs) recently
found in the Magellanic Clouds. The modeling of archival orbital light curves
(LCs), along with the analysis of the radial velocities suggest that this
object is a semi--detached binary with the less massive star transferring
matter to the more massive and less evolved star, in an Algol--like
configuration. We find evidence for additional orbital variability and
H$\alpha$ emission, likely caused by an accretion disc around the primary star.
As in the case of $\beta Lyr$ the circumprimary disc seems to be more luminous
than the primary, but we do not detect orbital period changes. We find that the
LC follows a loop in the color--magnitude diagram during the long cycle; the
system is redder when brighter and the rising phase is bluer than during
decline. Infrared excess is also present. The source of the long--term
periodicity is not eclipsed, indicating its circumbinary origin. Strong
asymmetries, discrete absorption components (DACs) and a $\gamma$ shift are new
and essential observational properties in the infrared H I lines. The DACs
strength and RV follow a saw--teeth pattern during the orbital cycle. We
suggest that the system experiences supercycles of mass outflow feeding a
circumbinary disc. Mass exchange and mass loss could produce comparable but
opposite effects in the orbital period on a long time scale, resulting in a
quasi--constancy of this parameter.


title: A Schur-type addition theorem for primes

abstract:
  Suppose that all primes are colored with k colors. Then there exist
monochromatic primes p1, p2, p3 such that p1+p2=p3+1.


title: BCS approximation to the effective vector vertex of superfluid fermions

abstract:
  We examine the effective interaction of nonrelativistic fermions with an
external vector field in superfluid systems. In contrast to the complicated
vertex equation, usually used in this case, we apply the approach which does
not employ an explicit form of the pairing interaction. This allows to obtain a
simple analytic expression for the vertex function only in terms of the order
parameter and other macroscopic parameters of the system. We use this effective
vertex to analyze the linear response function of the superfluid medium at
finite temperatures. At the time-like momentum transfer, the imaginary part of
the response function is found to be proportional to the fourth power of small
Fermi velocity, i.e. the energy losses through vector currents are strongly
suppressed. As an application, we calculate the neutrino energy losses through
neutral weak currents caused by the pair recombination in the superfluid
neutron matter at temperatures lower than the critical one for S-wave pairing.
This approach confirms a strong suppression of the neutrino energy losses as
predicted in Ref.[4].


title: Sigma meson in QCD sum rules using a two quark current with derivatives

abstract:
  We study the $\sigma$ meson in QCD sum rules using a two quark interpolating
field with derivatives. In the constituent quark model, the $\sigma$ meson is
composed of a quark and an antiquark in the relative p-wave state and is thus
expected to have a larger overlap with an interpolating field that measures the
derivative of the relative quark wave-function. While the sum rule with a
current without derivatives gives a pole mass of around 1 GeV, the present sum
rule with a derivative current gives a mass of around 550 MeV and a width of
400 MeV, that could be identified with the $\sigma$ meson.


title:
Doubly degenerate orbital system in honeycomb lattice: implication of
  orbital state in layered iron oxide

abstract:
  We study a doubly-degenerate orbital model on a honeycomb attice. This is a
model for orbital states in multiferroic layered iron oxides. The classical and
quantum models are analyzed by spin-wave approximation, Monte-Carlo simulation
and Lanczos method. A macroscopic number of degeneracy exists in the classical
ground state. In the classical model, a peak in the specific heat appears at a
temperature which is much lower than the mean-field ordering one. Below this
temperature, angle of orbital pseudo-spin is fixed, but conventional orbital
orders are not suggested. The degeneracy in the ground state is partially
lifted by thermal fluctuation. We suggest a role of zero-dimensional
fluctuation in hexagons on a low-temperature orbital structure. Lifting of the
degeneracy also occurs at zero temperature due to the quantum zero-point
fluctuation. We show that the ground-state wave function is well represented by
a linear combination of the states where a honeycomb lattice is covered by
nearest-neighboring pairs of orbitals with the minimum bond energy.


title: Symmetries of some motivic integrals

abstract:
  We give an explicit formula for the motivic integrals related to the Milnor
number over spaces of parametrised arcs on the plane with fixed tangency orders
with the axis. These integrals are rational functions of the parameters and the
class of the affine line. Using a set of natural recurrence relations between
them, we prove an unexpected invariance property with respect to the
simultaneous inversion of the parameters and the class of the affine line. We
also discuss a generalization of this system of recurrence relations whose
solutions are also symmetric and satisfy additional differential equations.


title: Concave functions of positive operators, sums and congruences

abstract:
  Subaddivity type matrix inequalities for concave funcions and symetric norms
are given.


title:
Systematics of linearization of N = 2 nonlinear SUSY in superfield
  formulation

abstract:
  The relation between a N = 2 nonlinear supersymmetric (SUSY) model and a
linear SUSY (free) theory for $N = 2$ vector supermultiplet accompanying the
spontaneous SUSY breaking is systematically worked out in two-dimensional
superfield formulation.


title: Production of Spin-Two Gauge Bosons

abstract:
  We considered spin-two gauge boson production in the fermion pair
annihilation process and calculated the polarized cross sections for each set
of helicity orientations of initial and final particles. The angular dependence
of these cross sections is compared with the similar annihilation cross
sections in QED with two photons in the final state, with two gluons in QCD and
W-pair in Electroweak theory.


title:
Markov Jump Processes Approximating a Nonsymmetric Generalized
  Diffusion: numerics explained to probabilists

abstract:
  Consider a non-symmetric generalized diffusion $X(\cdot)$ in ${\bbR}^d$
determined by the differential operator $A(\msx)=-\sum_{ij}
\partial_ia_{ij}(\msx)\partial_j +\sum_i b_i(\msx)\partial_i$. In this paper
the diffusion process is approximated by Markov jump processes $X_n(\cdot)$, in
homogeneous and isotropic grids $G_n \subset {\bbR}^d$, which converge in
distribution to the diffusion $X(\cdot)$. The generators of $X_n(\cdot)$ are
constructed explicitly. Due to the homogeneity and isotropy of grids, the
proposed method for $d\geq3$ can be applied to processes for which the
diffusion tensor $\{a_{ij}(\msx)\}_{11}^{dd}$ fulfills an additional condition.
The proposed construction offers a simple method for simulation of sample paths
of non-symmetric generalized diffusion. Simulations are carried out in terms of
jump processes $X_n(\cdot)$. For $d=2$ the construction can be easily
implemented into a computer code.


title:
Galactic HI on the 50-AU scale in the direction of three extra-galactic
  sources observed with MERLIN

abstract:
  We present MERLIN observations of Galactic 21-cm HI absorption at an angular
resolution of c. 0.1-0.2 arcsec and a velocity resolution of 0.5 km/s, in the
direction of three moderately low latitude (-8< b <-12 deg) extragalactic radio
sources, 3C111, 3C123 and 3C161, all of which are heavily reddened. HI
absorption is observed against resolved background emission sources up to c. 2
arcsec in extent and we distinguish details of the opacity distribution within
1-1.5 arcsec regions towards 3C~123 and 3C~161. This study is the second MERLIN
investigation of small scale structure in interstellar HI (earlier work probed
Galactic HI in the directions of the compact sources 3C138 and 3C147). The
0.1-arcsec scale is intermediate between HI absorption studies made with other
fixed element interferometers with resolution of 1 to 10 arcsec and VLBI
studies with resolutions of 10-20 milli-arcsec. At a scale of 1 arcsec (about
500 AU), prominent changes in Galactic HI opacity in excess of 1-1.5 are
determined in the direction of 3C161 with a signal-to-noise ratio of at least
10 sigma. Possible fluctuations in the HI opacity at the level of about 1 are
detected at the 2.5-3 sigma level in the direction of 3C123.


title: Hydrodynamic Interactions in Two Dimensions

abstract:
  We measure hydrodynamic interactions between colloidal particles confined in
a thin sheet of fluid. The reduced dimensionality, compared to a bulk fluid,
increases dramatically the range of couplings. Using optical tweezers we force
a two body system along the eigenmodes of the mobility tensor and find that
eigen-mobilities change logarithmically with particle separation. At a hundred
radii distance, the mobilities for correlated and anti-correlated motions
differ by a factor of two, whereas in bulk fluids, they would be practically
indistinguishable. We derive the two dimensional counterpart of the Oseen
hydrodynamic tensor which quantitatively reproduces the observed behavior.
These results highlight the importance of dimensionality for transport and
interactions in colloidal systems and proteins in biological membranes.


title: Quantum Fields and Translations

abstract:
  Modifications of a free quantum field calculation using translation-related
concepts and general translation representations yield quantum fields for
massive particles that as a consequence follow the classical trajectories of
electrodynamics and geometrodynamics. The work allows an explanation for the
unexpectedly high energy of cosmic rays. The explanation can be tested at the
Large Hadron Collider once high energy proton beams are operational.


title:
On the Influence of Selection Operators on Performances in Cellular
  Genetic Algorithms

abstract:
  In this paper, we study the influence of the selective pressure on the
performance of cellular genetic algorithms. Cellular genetic algorithms are
genetic algorithms where the population is embedded on a toroidal grid. This
structure makes the propagation of the best so far individual slow down, and
allows to keep in the population potentially good solutions. We present two
selective pressure reducing strategies in order to slow down even more the best
solution propagation. We experiment these strategies on a hard optimization
problem, the quadratic assignment problem, and we show that there is a value
for of the control parameter for both which gives the best performance. This
optimal value does not find explanation on only the selective pressure,
measured either by take over time and diversity evolution. This study makes us
conclude that we need other tools than the sole selective pressure measures to
explain the performances of cellular genetic algorithms.


title:
Surviving particles for subcritical branching processes in random
  environment

abstract:
  The asymptotic behavior of a subcritical Branching Process in Random
Environment (BPRE) starting with several particles depends on whether the BPRE
is strongly subcritical (SS), intermediate subcritical (IS) or weakly
subcritical (WS). %Descendances of particles for BPRE are not independent. In
the (SS+IS) case, the asymptotic probability of survival is proportional to the
initial number of particles, and conditionally on the survival of the
population, only one initial particle survives $a.s.$ These two properties do
not hold in the (WS) case and different asymptotics are established, which
require new results on random walks with negative drift. We provide an
interpretation of these results by characterizing the sequence of environments
selected when we condition on the survival of particles. This also raises the
problem of the dependence of the Yaglom quasistationary distributions on the
initial number of particles and the asymptotic behavior of the Q-process
associated with a subcritical BPRE.


title:
Temperature dependence of the slip length in polymer melts at attractive
  surfaces

abstract:
  Using Couette and Poiseuille flow, we extract the temperature dependence of
the slip length, $\delta$, from molecular dynamics simulations of a
coarse-grained polymer model in contact with an attractive, corrugated surface.
$\delta$ is dictated by the ratio of bulk viscosity and surface mobility. At
weakly attractive surfaces, a lubrication layer forms, $\delta$ is large and
increases upon cooling. Close to the glass transition temperature, $T_ g$, very
large slip lengths are observed. At a more attractive surface, a``stick y
surface layer" is build up, which gives rise to a small slip length. Upon cool
ing, $\delta$ decreases at high temperatures, passes through a minimum and
grows upon approaching $T_g$. At strongly attractive surfaces, the Navier-slip
condit ion fails to describe Couette and Poiseuille flow simultaneously. The
simulation results are corroborated by a schematic, two-layer model suggesting
that the ob servations do not depend on the details of the computational model.


title:
Gibbons-Hawking Boundary Terms and Junction Conditions for Higher-Order
  Brane Gravity Models

abstract:
  We derive the most general junction conditions for the fourth-order brane
gravity constructed of arbitrary functions of curvature invariants. We reduce
these fourth-order theories to second order theories at the expense of
introducing new scalar and tensor fields - the scalaron and the tensoron. In
order to obtain junction conditions we apply the method of generalized
Gibbons-Hawking boundary terms which are appended to the appropriate actions.
After assuming the continuity of the scalaron and the tensoron on the brane, we
recover junction conditions for such general brane universe models previously
obtained by different methods. The derived junction conditions can serve
studying the cosmological implications of the higher-order brane gravity
models.


title: Data acquisition system for the TUNKA-133 array

abstract:
  The new EAS Cherenkov array TUNKA-133, with about 1 km**2 sensitive area, is
being installed in the Tunka Valley. The investigated energy range is
10**15-10**18 eV. It will consist of 133 optical detectors based on EMI9350
PMTs. Optical detectors are grouped into 19 clusters with 7 detectors each. The
detectors are connected to the cluster box with RG-58 cables. Every PMT signal
is digitized in the cluster box with 200 MHz FADC. The cluster boxes are
connected to the data acquisition center with a 1 Gb/s optical link. A detailed
description of the data acquisition system (DAQ) is presented.


title:
A spatial interpretation of emerging superconductivity in lightly doped
  cuprates

abstract:
  The formation of domains comprising alternating 'hole rich' and 'hole poor'
ladders recently observed by Scanning Tunneling Microscopy by Kohsaka et al.,
on lightly hole doped cuprates, is interpreted in terms of an attractive
mechanism which favors the presence of doped holes on Cu sites located each on
one side of an oxygen atom. This mechanism leads to a geometrical pattern of
alternating hole-rich and hole-poor ladders with a periodicity equal to 4 times
the lattice spacing in the CuO plane, as observed experimentally. To cite this
article: G. Deutscher, P.-G. de Gennes, C. R. Physique 8 (2007).


title:
The Collimated Jet Source in IRAS 16547-4247: Time Variation, Possible
  Precession, and Upper Limits to the Proper Motions Along the Jet Axis

abstract:
  The triple radio source detected in association with the luminous infrared
source IRAS 16547-4247 has previously been studied with high angular resolution
and high sensitivity with the Very Large Array (VLA) at 3.6-cm wavelength. In
this paper, we present new 3.6 cm observations taken 2.68 years after the first
epoch that allow a search for variability and proper motions, as well as the
detection of additional faint sources in the region. We do not detect proper
motions along the axis of the outflow in the outer lobes of this source at a
4-$\sigma$ upper limit of $\sim$160 km s$^{-1}$. This suggests that these lobes
are probably working surfaces where the jet is interacting with a denser
medium. However, the brightest components of the lobes show evidence of
precession, at a rate of $0\rlap.^\circ08$ yr$^{-1}$ clockwise in the plane of
the sky. It may be possible to understand the distribution of almost all the
identified sources as the result of ejecta from a precessing jet. The core of
the thermal jet shows significant variations in flux density and morphology. We
compare this source with other jets in low and high mass young stars and
suggest that the former can be understood as a scaled-up version of the latter.


title: Mechanochemical action of the dynamin protein

abstract:
  Dynamin is a ubiquitous GTPase that tubulates lipid bilayers and is
implicated in many membrane severing processes in eukaryotic cells. Setting the
grounds for a better understanding of this biological function, we develop a
generalized hydrodynamics description of the conformational change of large
dynamin-membrane tubes taking into account GTP consumption as a free energy
source. On observable time scales, dissipation is dominated by an effective
dynamin/membrane friction and the deformation field of the tube has a simple
diffusive behavior, which could be tested experimentally. A more involved,
semi-microscopic model yields complete predictions for the dynamics of the tube
and possibly accounts for contradictory experimental results concerning its
change of conformation as well as for plectonemic supercoiling.


title:
Super-potentials for currents on compact Kaehler manifolds and dynamics
  of automorphisms

abstract:
  We introduce a notion of super-potential (canonical function) associated to
positive closed (p,p)-currents on compact Kaehler manifolds and we develop a
calculus on such currents. One of the key points in our study is the use of
deformations in the space of currents. As an application, we obtain several
results on the dynamics of holomorphic automorphisms: regularity and uniqueness
of the Green currents. We also get the regularity, the entropy, the ergodicity
and the hyperbolicity of the equilibrium measures.


title:
Probing the creatable character of perturbed Friedmann-Robertson-Walker
  universes

abstract:
  We discuss whether some perturbed Friedmann-Robertson-Walker (FRW) universes
could be creatable, i. e., could have vanishing energy, linear momentum and
angular momentum, as it could be expectable if the Universe arose as a quantum
fluctuation. On account of previous results, the background is assumed to be
either closed (with very small curvature) or flat. In the first case, fully
arbitrary linear perturbations are considered; whereas in the flat case, it is
assumed the existence of: (i) inflationary scalar perturbations, that is to
say, Gaussian adiabatic scalar perturbations having an spectrum close to the
Harrison-Zel'dovich one, and (ii) arbitrary tensor perturbations. We conclude
that, any closed perturbed universe is creatable, and also that, irrespective
of the spectrum and properties of the inflationary gravitational waves,
perturbed flat FRW universes with standard inflation are not creatable. Some
considerations on pre-inflationary scalar perturbations are also presented. The
creatable character of perturbed FRW universes is studied, for the first time,
in this paper.


title: On ad hoc routing with guaranteed delivery

abstract:
  We point out a simple poly-time log-space routing algorithm in ad hoc
networks with guaranteed delivery using universal exploration sequences.


title: Non-thermal Dark Matter and the Moduli Problem in String Frameworks

abstract:
  We address the cosmological moduli/gravitino problems and the issue of too
little thermal but excessive non-thermal dark matter from the decays of moduli.
The main examples we study are the G2-MSSM models arising from M theory
compactifications, which allow for a precise calculation of moduli decay rates
and widths. We find that the late decaying moduli satisfy both BBN constraints
and avoid the gravitino problem. The non-thermal production of wino LSPs, which
is a prediction of G2-MSSM models, gives a relic density of about the right
order of magnitude.


title: Sparse Approximate Solution of Partial Differential Equations

abstract:
  A new concept is introduced for the adaptive finite element discretization of
partial differential equations that have a sparsely representable solution.
Motivated by recent work on compressed sensing, a recursive mesh refinement
procedure is presented that uses linear programming to find a good
approximation to the sparse solution on a given refinement level. Then only
those parts of the mesh are refined that belong to large expansion
coefficients. Error estimates for this procedure are refined and the behavior
of the procedure is demonstrated via some simple elliptic model problems.


title:
On the ring of approximation triples attached to a class of extremal
  real numbers

abstract:
  We attach a ring of sequences to each number from a certain class of extremal
real numbers, and we study the properties of this ring both from an analytic
point of view by exhibiting elements with specific behaviors, and also from an
algebraic point of view by identifying it with the quotient of a polynomial
ring over Q. The link between these points of view relies on combinatorial
results of independent interest. We apply this theory to estimate the dimension
of a certain space of sequences satisfying prescribed growth constrains.


title:
Mott State and Quantum Critical Points in Rare-Earth Oxypnictides
  $RO_{1-x}F_xFeAs$ ($R=La, Sm, Nd, Pr, Ce$)

abstract:
  We investigate the magnetic phase diagram of the newly discovered iron-based
high temperature oxypnictide superconductors of the type RO$_{1-x}$F$_x $FeAs,
with rare earths R=La, Sm, Nd, Pr and Ce by means of {\it ab initio} SGGA and
SGGA+U density functional computations. We find undoped LaOFeAs to be a Mott
insulator when incorporating electronic correlations via SGGA+U for any
physically relevant value of $U$. The doped compounds are according to SGGA
conductors with a transition from an antiferromagnetic to a non-magnetic state
at a hole doping of concentration $x_c$=0.075 for R=Nd, Pr and at electron
doping $x_c$=0.25 for Ce and 0.6 for Sm. Superconductivity in these rare-earth
oxypnictides thus appears in the vicinity of a magnetic quantum critical point
where electronic correlations are expected to play an important role because of
the vicinity of a Mott insulating state at zero doping.


title: Clique percolation

abstract:
  Derenyi, Palla and Vicsek introduced the following dependent percolation
model, in the context of finding communities in networks. Starting with a
random graph $G$ generated by some rule, form an auxiliary graph $G'$ whose
vertices are the $k$-cliques of $G$, in which two vertices are joined if the
corresponding cliques share $k-1$ vertices. They considered in particular the
case where $G=G(n,p)$, and found heuristically the threshold for a giant
component to appear in $G'$. Here we give a rigorous proof of this result, as
well as many extensions. The model turns out to be very interesting due to the
essential global dependence present in $G'$.


title:
Strain rate effects in the mechanical response of polymer anchored
  carbon nanotube foams

abstract:
  Super-compressible foam-like carbon nanotube films have been reported to
exhibit highly nonlinear viscoelastic behaviour in compression similar to soft
tissue. Their unique combination of light weight and exceptional electrical,
thermal and mechanical properties have helped identify them as viable building
blocks for more complex nanosystems and as stand-alone structures for a variety
of different applications. In the as-grown state, their mechanical performance
is limited by the weak adhesion between the tubes, controlled by the van der
Waals forces, and the substrate allowing the forests to split easily and to
have low resistance in shear. Under axial compression loading carbon nanotubes
have demonstrated bending, buckling8 and fracture9 (or a combination of the
above) depending on the loading conditions and on the number of loading cycles.
In this work, we partially anchor dense vertically aligned foam-like forests of
carbon nanotubes on a thin, flexible polymer layer to provide structural
stability, and report the mechanical response of such systems as a function of
the strain rate. We test the sample under quasi-static indentation loading and
under impact loading and report a variable nonlinear response and different
elastic recovery with varying strain rates. A Bauschinger-like effect is
observed at very low strain rates while buckling and the formation of permanent
defects in the tube structure is reported at very high strain rates. Using
high-resolution transmission microscopy


title:
Triple unification of inflation, dark matter, and dark energy using a
  single field

abstract:
  We construct an explicit scenario whereby the same material driving inflation
in the early Universe can comprise dark matter in the present Universe, using a
simple quadratic potential. Following inflation and preheating, the density of
inflaton/dark matter particles is reduced to the observed level by a period of
thermal inflation, of a duration already invoked in the literature for other
reasons. Within the context of the string landscape, one can further argue for
a non-zero vacuum energy of this field, thus unifying inflation, dark matter
and dark energy into a single fundamental field.


title: Generalized uncertainty inequalities

abstract:
  In this paper, Heisenberg-Pauli-Weyl-type uncertainty inequalities are
obtained for a pair of positive-self adjoint operators on a Hilbert space,
whose spectral projectors satisfy a ``balance condition'' involving certain
operator norms. This result is then applied to obtain uncertainty inequalities
on Riemannian manifolds, Riemannian symmetric spaces of non-compact type,
homogeneous graphs and unimodular Lie groups with sublaplacians.


title:
Quantum randomness can be controlled by free will -a consequence of the
  before-before experiment

abstract:
  The before-before experiment demonstrates that quantum randomness can be
controlled by influences from outside spacetime, and therefore by immaterial
free will. Rather than looking at quantum physics as the model for explaining
free will, one should look at free will as a primitive principle for explaining
why the laws of Nature are quantum.


title: Analytic QCD - a short review

abstract:
  Analytic versions of QCD are those whose coupling alpha_s(Q^2) does not have
the unphysical Landau singularities on the space-like axis (-q^2=Q^2 > 0). The
coupling is analytic in the entire complex plane except the time-like axis (Q^2
< 0). Such couplings are thus suitable for application of perturbative methods
down to energies of order GeV. We present a short review of the activity in the
area which started with a seminal paper of Shirkov and Solovtsov ten years ago.
Several models for analytic QCD coupling are presented. Strengths and
weaknesses of some of these models are pointed out. Further, for such analytic
couplings, constructions of the corresponding higher order analytic couplings
(the analogs of the higher powers of the perturbative coupling) are outlined,
and an approach based on the renormalization group considerations is singled
out. Methods of evaluation of the leading-twist part of space-like observables
in such analytic frameworks are described. Such methods are applicable also to
the inclusive time-like observables. Two analytic models are outlined which
respect the ITEP Operator Product Expansion philosophy, and thus allow for an
evaluation of higher-twist contributions to observables.


title: The Cauchy two-matrix model

abstract:
  We introduce a new class of two(multi)-matrix models of positive Hermitean
matrices coupled in a chain; the coupling is related to the Cauchy kernel and
differs from the exponential coupling more commonly used in similar models. The
correlation functions are expressed entirely in terms of certain biorthogonal
polynomials and solutions of appropriate Riemann-Hilbert problems, thus paving
the way to a steepest descent analysis and universality results. The
interpretation of the formal expansion of the partition function in terms of
multicolored ribbon-graphs is provided and a connection to the O(1) model. A
steepest descent analysis of the partition function reveals that the model is
related to a trigonal curve (three-sheeted covering of the plane) much in the
same way as the Hermitean matrix model is related to a hyperelliptic curve.


title:
A class of solutions of the vacuum Einstein constraint equations with
  freely specified mean curvature

abstract:
  We give a sufficient condition, with no restrictions on the mean curvature,
under which the conformal method can be used to generate solutions of the
vacuum Einstein constraint equations on compact manifolds. The condition
requires a so-called global supersolution but does not require a global
subsolution. As a consequence, we construct a class of solutions of the vacuum
Einstein constraint equations with freely specified mean curvature, extending a
recent result of Holst, Nagy, and Tsogtgerel [HNT07] which constructed similar
solutions in the presence of matter. We give a second proof of this result
showing that vacuum solutions can be obtained as a limit of [HNT07] non-vacuum
solutions. Our principal existence theorem is of independent interest in the
near-CMC case, where it simplifies previously known hypotheses required for
existence.


title:
Direct Observation of Dark Excitons in Individual Carbon Nanotubes: Role
  of Local Environments

abstract:
  We report the direct observation of the spin-singlet dark excitonic state in
individual single-walled carbon nanotubes through low-temperature
micro-photoluminescence spectroscopy in magnetic fields. A magnetic field up to
5 T, applied along the nanotube axis, brightened the dark state, leading to the
emergence of a new emission peak. The peak rapidly grew in intensity with
increasing field at the expense of the originally-dominant bright exciton peak
and finally became dominant at fields $>$3 T. This behavior, universally
observed for more than 50 nanotubes of different chiralities, can be
quantitatively explained through a model incorporating the Aharonov-Bohm effect
and intervalley Coulomb mixing, unambiguously proving the existence of dark
excitons. The directly measured dark-bright splitting values were 1-4 meV for
tube diameters 1.0-1.3 nm. Scatter in the splitting value emphasizes the role
of the local environment surrounding a nanotube in determining the excitonic
fine structure of single-walled carbon nanotubes.


title: Semi-continuous Sized Types and Termination

abstract:
  Some type-based approaches to termination use sized types: an ordinal bound
for the size of a data structure is stored in its type. A recursive function
over a sized type is accepted if it is visible in the type system that
recursive calls occur just at a smaller size. This approach is only sound if
the type of the recursive function is admissible, i.e., depends on the size
index in a certain way. To explore the space of admissible functions in the
presence of higher-kinded data types and impredicative polymorphism, a
semantics is developed where sized types are interpreted as functions from
ordinals into sets of strongly normalizing terms. It is shown that upper
semi-continuity of such functions is a sufficient semantic criterion for
admissibility. To provide a syntactical criterion, a calculus for
semi-continuous functions is developed.


title: Mathematical Models in Physics : a Quest for Clarity

abstract:
  The role of mathematical models in physics has for longer been well
established. The issue of their proper building and use appears to be less
clear. Examples in this regard from relativity and quantum mechanics are
mentioned. Comments concerning a more appropriate way in setting up and using
mathematical models in physics are presented.


title: Particle partitioning entanglement in itinerant many-particle systems

abstract:
  For itinerant fermionic and bosonic systems, we study `particle
entanglement', defined as the entanglement between two subsets of particles
making up the system. We formulate the general structure of particle
entanglement in many-fermion ground states, analogous to the `area law' for the
more usually studied entanglement between spatial regions. Basic properties of
particle entanglement are uncovered by considering relatively simple itinerant
models.


title: The equations of the ideal latches

abstract:
  The latches are simple circuits with feedback from the digital electrical
engineering. We have included in our work the C element of Muller, the RS
latch, the clocked RS latch, the D latch and also circuits containing two
interconnected latches: the edge triggered RS flip-flop, the D flip-flop, the
JK flip-flop, the T flip-flop. The purpose of this study is to model with
equations the previous circuits, considered to be ideal, i.e. non-inertial. The
technique of analysis is the pseudoboolean differential calculus.


title:
Millimeter- and Submillimeter-Wave Observations of the OMC-2/3 Region.
  II. Observational Evidence for Outflow-Triggered Star Formation in the OMC-2
  FIR 3/4 Region

abstract:
  We have carried out the observations of the OMC-2 FIR 3/4 region with the NMA
and ASTE in the H$^{13}$CO$^{+}$ (1--0), $^{12}$CO (3--2, 1--0), SiO ($v$=0,
$J$=2--1), CS (2--1), and CH$_3$OH ($J_K$=7$_K$--6$_K$) lines and in the 3.3 mm
continuum emission. Our NMA observations in the H$^{13}$CO$^{+}$ emission have
revealed 0.07 pc-scale dense gas associated with FIR 4. The $^{12}$CO
(3--2,1--0) emission shows high-velocity blue and red shifted components at the
both north-east and south-west of FIR 3, suggesting a molecular outflow nearly
along the plane of the sky driven by FIR 3. The SiO and the CH$_{3}$OH emission
are detected around the interface between the outflow and the dense gas.
Furthermore, the $^{12}$CO (1--0) emission shows an L-shaped structure in the
P-V diagram. These results imply presence of the shock due to the interaction
between the molecular outflow driven by FIR 3 and the dense gas associated with
FIR 4. Moreover, our high angular-resolution observations of FIR 4 in the 3.3
mm continuum emission have first found that FIR 4 consists of eleven dusty
cores. The separation among these cores is on the same order of the Jeans
length, suggesting that the fragmentation into these cores has been caused by
the gravitational instability. The time scale of the fragmentation is similar
to the time scale of the interaction between the molecular outflow and the
dense gas. We suggest that the interaction between the molecular outflow from
FIR 3 and the dense gas associated with FIR 4 triggered the fragmentation into
these dusty cores, and hence the next generation the cluster formation.


title: Energy and Angular Momentum of Dilaton Black Holes

abstract:
  Following a prior paper, we review the results for the energy and angular
momentum of a Kerr-Newman black hole, and then calculate the same properties
for the case of a generalised rotating dilaton of the type derived, without
rotation, by Garfinkle, Horowitz, and Strominger (1991; 1992). We show that
there is, as far as it refers only to the energy and angular momentum, an
interaction among the fields, so that, the gravitational and electromagnetic
fields may be obscured by the strength of the scalar field.


title:
Contraction and restriction of positroids in terms of decorated
  permutations

abstract:
  A positroid is a matroid defined by Postnikov to study the cells in the
non-negative part of the Grassmannian. They are in bijection with decorated
permutations. We show a way to explain contraction and restriction of
positroids in terms of decorated permutations.


title:
Universal Scaling of Pinning Effect on Hall Anomaly near the Vortex
  Glass Transition and Doping Dependence Problems of Superconductors

abstract:
  We find universal scaling relations of the pinning effect on the Hall
resistivity $\rho_{xy}$ and Hall angle $\theta_{H}$. Considering the extended
power law form of $\rho_{xx}$ and the microscopic analysis of $\sigma_{xy}$, we
obtain unified $\rho_{xy}$ equations for superconductors with and without
double sign reversal. These equations reasonably explain the striking
universality in doping dependence found by Nagoaka et al., which contradicts
the prediction of the time dependent Ginzburg-Landau equation based on s-wave
coupling theory [PRL {\bf{80}},3594 (1998)]. A full comparison of experiment
with prediction from theoretical models is proposed.


title: Breakdown of Bell's Theorem for incompatible measurements

abstract:
  Bell's theorem contains the proposition that the Einstein-Podolsky-Rosen
(EPR) theory (hypothesis) of the existence of elements of reality together with
Einstein locality permits a mathematical description of EPR experiments by
functions that are all defined on one common probability space. This
proposition leads in turn to restrictions for possible experimental outcomes
that Bell expressed in terms of his well known inequalities and that Vorob'ev
and others had investigated before Bell. Summarizing several previous
publications and adding new material, the above proposition is refuted by
Einstein-local counterexamples from classical physics and shown to involve
additional assumptions that can not be justified for mutually exclusive
(incompatible) measurements and experiments. Moreover, criticism of our work by
Mermin who invoked "standard sampling arguments" is shown to be false.


title:
Positiveness and Pauli exception principle in raw Bloch equations for
  quantum boxes

abstract:
  The aim of this paper is to derive a raw Bloch model for the interaction of
light with quantum boxes in the framework of a two-electron-species (conduction
and valence) description. This requires a good understanding of the one-species
case and of the treatment of level degeneracy. In contrast with some existing
literature we obtain a Liouville equation which induces the positiveness and
the boundedness of solutions, that are necessary for future mathematical
studies involving higher order phenomena.


title: On Gaussian Brunn-Minkowski inequalities

abstract:
  In this paper, we are interested in Gaussian versions of the classical
Brunn-Minkowski inequality. We prove in a streamlined way a semigroup version
of the Ehrard inequality for $m$ Borel or convex sets based on a previous work
by Borell. Our method also allows us to have semigroup proofs of the geometric
Brascamp-Lieb inequality and of the reverse one which follow exactly the same
lines.


title:
Determining gap nodal structures in Fe-based superconductors:
  angle-dependence of the low temperature specific heat in an applied magnetic
  field

abstract:
  Since the discovery of high-Tc LaO_1-xF_xFeAs, and other such systems based
on FeAs layers, several proposals have been made for the superconducting order
parameter Delta_k, on both phenomenological and microscopic grounds. Here we
discuss how the symmetry of Delta_k in the bulk can be determined, assuming
that single crystals will soon be available. We suggest that a measurement of
the dependence of the low temperature specific heat on the angle of a magnetic
field in the FeAs plane is the simplest such method, and calculate
representative specific heat vs. field angle oscillations for the various
candidate states, using a phenomenological band structure fitted to the DFT
Fermi surface.


title:
Superconductivity-Induced Self-Energy Evolution of the Nodal Electron of
  Optimally-Doped Bi2212

abstract:
  The temperature dependent evolution of the renormalization effect in
optimally-doped Bi2212 along the nodal direction has been studied via
angle-resolved photoemission spectroscopy. Fine structure is observed in the
real part of the self-energy (Re$\Sigma$), including a subkink and maximum,
suggesting that electrons couple to a spectrum of bosonic modes, instead of
just one mode. Upon cooling through the superconducting phase transition, the
fine structures of the extracted Re$\Sigma$ exhibit a two-processes evolution
demonstrating an interplay between kink renormalization and superconductivity.
We show that this two-process evolution can be qualitatively explained by a
simple Holstein model in which a spectrum of bosonic modes is considered.


title: Spiked Models in Wishart Ensemble

abstract:
  The spiked model is an important special case of the Wishart ensemble, and a
natural generalization of the white Wishart ensemble. Mathematically, it can be
defined on three kinds of variables: the real, the complex and the quaternion.
For practical application, we are interested in the limiting distribution of
the largest sample eigenvalue.
  We first give a new proof of the result of Baik, Ben Arous and P\'{e}ch\'{e}
for the complex spiked model, based on the method of multiple orthogonal
polynomials by Bleher and Kuijlaars. Then in the same spirit we present a new
result of the rank 1 quaternionic spiked model, proven by combinatorial
identities involving quaternionic Zonal polynomials (\alpha = 1/2 Jack
polynomials) and skew orthogonal polynomials.
  We find a phase transition phenomenon for the limiting distribution in the
rank 1 quaternionic spiked model as the spiked population eigenvalue increases,
and recognize the seemingly new limiting distribution on the critical point as
the limiting distribution of the largest sample eigenvalue in the real white
Wishart ensemble.
  Finally we give conjectures for higher rank quaternionic spiked model and the
real spiked model.


title: Advantages of Randomization in Coherent Quantum Dynamical Control

abstract:
  Control scenarios have been identified where the use of randomized design may
substantially improve the performance of dynamical decoupling methods [L. F.
Santos and L. Viola, Phys. Rev. Lett. {\bf 97}, 150501 (2006)]. Here, by
focusing on the suppression of internal unwanted interactions in closed quantum
systems, we review and further elaborate on the advantages of randomization at
long evolution times. By way of illustration, special emphasis is devoted to
isolated Heisenberg-coupled chains of spin-1/2 particles. In particular, for
nearest-neighbor interactions, two types of decoupling cycles are contrasted:
inefficient averaging, whereby the number of control actions increases
exponentially with the system size, and efficient averaging associated to a
fixed-size control group. The latter allows for analytical and numerical
studies of efficient decoupling schemes created by exploiting and merging
together randomization and deterministic strategies, such as symmetrization,
concatenation, and cyclic permutations. Notably, sequences capable to remove
interactions up to third order are explicitly constructed. The consequences of
faulty controls are also analyzed.


title:
Security of entanglement-based quantum key distribution with practical
  detectors

abstract:
  We prove the unconditional security of an entanglement-based
quantum-key-distribution protocol using detectors that respond to multiple
modes of light and cannot distinguish between one from two or more photons.
Even with such practical detectors, any defect in the source is automatically
detected as an increase in the error rate or in the rate of double clicks.


title:
The probability distribution of cluster formation times and implied
  Einstein Radii

abstract:
  We provide a quantitative assessment of the probability distribution function
of the concentration parameter of galaxy clusters. We do so by using the
probability distribution function of halo formation times, calculated by means
of the excursion set formalism, and a formation redshift-concentration scaling
derived from results of N-body simulations. Our results suggest that the
observed high concentrations of several clusters are quite unlikely in the
standard Lambda CDM cosmological model, but that due to various inherent
uncertainties, the statistical range of the predicted distribution may be
significantly wider than commonly acknowledged. In addition, the probability
distribution function of the Einstein radius of A1689 is evaluated, confirming
that the observed value of ~45" +/- 5" is very improbable in the currently
favoured cosmological model. If, however, a variance of ~20% in the
theoretically predicted value of the virial radius is assumed, than the
discrepancy is much weaker. The measurement of similarly large Einstein radii
in several other clusters would pose a difficulty to the standard model. If so,
earlier formation of the large scale structure would be required, in accord
with predictions of some quintessence models. We have indeed verified that in a
viable early dark energy model large Einstein radii are predicted in as many as
a few tens of high-mass clusters.


title: Discrete elastic model for stretching-induced flagellar polymorphs

abstract:
  Force-induced reversible transformations between coiled and normal polymorphs
of bacterial flagella have been observed in recent optical-tweezer experiment.
We introduce a discrete elastic rod model with two competing helical states
governed by a fluctuating spin-like variable that represents the underlying
conformational states of flagellin monomers. Using hybrid Brownian dynamics
Monte-Carlo simulations, we show that a helix undergoes shape transitions
dominated by domain wall nucleation and motion in response to externally
applied uniaxial tension. A scaling argument for the critical force is
presented in good agreement with experimental and simulation results.
Stretching rate-dependent elasticity including a buckling instability are
found, also consistent with the experiment.


title:
Atomic models of non-stoichiometric layered diborides M$_{1-x}$B$_2$ (M
  = Mg, Al, Zr and Nb) from first principles

abstract:
  Two atomic models of non-stoichiometric metal diborides M$_{1-x}$B$_2$ are
now assumed: (i) the presence of cation vacancies and (ii) the presence of
'super-stoichiometric' boron which is placed in cation vacancy site. We have
performed first principle total energy calculations using the VASP-PAW method
with the generalized gradient approximation (GGA) for the exchange-correlation
potential in a perspective to reveal the trends of M$_{1-x}$B$_2$ possible
stable atomic configurations depending on the type of M cations (M = Mg, Al, Zr
or Nb) and the type of the defects (metal vacancies versus metal vacancies
occupied by 'super-stoichiometric' boron in forms of single atoms, dimers B$_2$
or trimers B$_3$). Besides we have estimated the stability of these
non-stoichiometric states (on the example of magnesium-boron system) as
depending on the possible synthetic routes, namely via solid state reaction
method, as well as in reactions between solid boron and Mg vapor; and between
these reagents in gaseous phase. We demonstrate that the non-stoichiometric
states such as B$_2$ and B$_3$ placed in metal sites may be stabilized, while
the occupation of vacancy sites by single boron atoms is the most unfavorable.


title:
Fermionization for charge degrees of freedom and bosonization of spin
  degrees of freedom in the SU(2) slave-boson theory

abstract:
  Fermionizing the charge sector and bosonizing the spin part in the SU(2)
slave-boson theory, we derive an effective field theory for dynamics of doped
holes in the antiferromagnetically correlated spin background, where spin
fluctuations are described by an SO(5) Wess-Zumino-Witten (WZW) theory while
dynamics of doped holes is characterized by QED$_{3}$ with a chemical potential
term. An important feature of our effective field theory is the coupling term
between valance bond fluctuations and doped holes. Considering that valance
bond fluctuations are deeply related with monopole excitations of staggered
U(1) gauge fields in the bosonic field theory for spin fluctuations, we
demonstrate that hole dynamics helps deconfinement of bosonic spinons near the
quantum critical point of the SO(5) WZW theory. We solve this effective field
theory in the Eliashberg framework, and find non-Fermi liquid physics in
thermodynamics and transport, where $z = 3$ criticality with dynamical exponent
$z$ plays an important role for hole dynamics. We discuss validity of our field
theory, applying it to a doped spin chain and comparing it with the
slave-fermion framework. Furthermore, we discuss instability of the anomalous
metallic phase against superconductivity and density waves of doped holes,
resulting from competition between gauge and valance bond fluctuations.


title: Evidence for CP violation in B0->J/Psi pi0 decays

abstract:
  We present measurements of the branching fraction and time-dependent CP
asymmetries in B0->J/Psi pi0 decays based on 466 million Y(4S)->BBbar events
collected with the BaBar detector at the SLAC PEP-II asymmetric-energy B
factory. We measure the CP asymmetry parameters
  S=-1.23 +/- 0.21 +/- 0.04 and C=-0.20 +/- 0.19 +/- 0.03, where the measured
value of S is 4.0 standard deviations from zero including systematic
uncertainties. The branching fraction is determined to be
  B(B0->J/Psi pi0)=(1.69 +/- 0.14 +/- 0.07)*10^{-5}.


title:
Elastic properties of mono- and polycrystalline hexagonal AlB2-like
  diborides of s, p and d metals from first-principles calculations

abstract:
  We have performed accurate ab initio total energy calculations using the
full-potential linearized augmented plane wave (FP-LAPW) method with the
generalized gradient approximation (GGA) for the exchange-correlation potential
to systematically investigate elastic properties of 18 stable, meta-stable and
hypothetical hexagonal (AlB2-like) metal diborides MB2, where M = Na, Be, Mg,
Ca, Al, Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Ag and Au. For monocrystalline
MB2 the optimized lattice parameters, independent elastic constants (Cij), bulk
modules (B), shear modules (G) are obtained and analyzed in comparison with the
available theoretical and experimental data. For the first time numerical
estimates of a set of elastic parameters of the polycrystalline MB2 ceramics
(in the framework of the Voigt-Reuss-Hill approximation), namely bulk and shear
modules, compressibility, Young's modules, Poisson's ratio, Lame's coefficients
are performed.


title:
V2051 Oph after superoutburst: out-of-plane material and the superhump
  light source

abstract:
  We performed a detailed spectroscopic analysis of the dwarf nova V2051 Oph at
the end of its 1999 superoutburst. We studied and interpreted the simultaneous
behaviour of various emission lines.
  We obtained high-resolution echelle spectroscopic data at ESO's NTT with
EMMI, covering the spectral range of 4000--7500 Angstrom. The analysis was
performed using standard IRAF tools. The indirect imaging technique of Doppler
tomography was applied, in order to map the accretion disc and distinguish
between the different emission sources.
  The spectra are characterised by strong Balmer emission, together with lines
of HeI and the iron triplet FeII 42. All lines are double-peaked, but the
blue-to-red peak strength and central absorption depth vary. The primary's
velocity was found to be 84.9 km/sec. The spectrograms of the emission lines
reveal the prograde rotation of a disc-like emitting region and, for the Balmer
and HeI lines, an enhancement of the red-wing during eclipse indicates a bright
spot origin. The modulation of the double-peak separation shows a highly
asymmetric disc with non-uniform emissivity. This is confirmed by the Doppler
maps, which apart from the disc and bright spot emission also indicate an
additional region of enhanced emission in the 4th quadrant (+Vx, -Vy), which we
associate with the superhump light source. Given the behaviour of the iron
triplet and its distinct differences from the rest of the lines, we attribute
its existence to an extended gas region above the disc. Its origin can be
explained through the fluorescence mechanism.


title: Deconfinement and Gluon Plasma Dynamics in Improved Holographic QCD

abstract:
  The finite temperature physics of the pure glue sector in the improved
holographic QCD model of arXiv:0707.1324 and arXiv:0707.1349 is addressed. The
thermodynamics of 5D dilaton gravity duals to confining gauge theories is
analyzed. We show that they exhibit a first order Hawking-Page type phase
transition. In the explicit background of arXiv:0707.1349, we find T_c = 235
MeV. The temperature dependence of various thermodynamic quantities such as the
pressure, entropy and speed of sound is calculated. The results show a good
agreement with the corresponding lattice data.


title: Nonlinear Fokker-Planck Equation in the Model of Asset Returns

abstract:
  The Fokker-Planck equation with diffusion coefficient quadratic in space
variable, linear drift coefficient, and nonlocal nonlinearity term is
considered in the framework of a model of analysis of asset returns at
financial markets. For special cases of such a Fokker-Planck equation we
describe a construction of exact solution of the Cauchy problem. In the general
case, we construct the leading term of the Cauchy problem solution asymptotic
in a formal small parameter in semiclassical approximation following the
complex WKB-Maslov method in the class of trajectory concentrated functions.


title: Clique Numbers of Graphs and Irreducible Exact m-Covers of Z

abstract:
  For each m>=1 and k>=2, we construct a graph G=(V,E) with \omega(G)=m such
that max_{1\leq i\leq k} \omega(G[V_i])=m for arbitrary partition
V=V_1\cup...\cup V_k, where \omega(G) is the clique number of G and G[V_i] is
the induced subgraph of G with the vertex set V_i. Using this result, we show
that for each m>=2 there exists an exact m-cover of Z which is not the union of
two 1-covers.


title: Time vs. Ensemble Averages for Nonstationary Time Series

abstract:
  We analyze the question whether sliding window time averages applied to
stationary increment processes converge to a limit in probability. The question
centers on averages, correlations, and densities constructed via time averages
of the increment x(t,T)=x(t+T)-x(t)and the assumption is that the increment is
distributed independently of t. We show that the condition for applying
Tchebyshev's Theorem to time averages of functions of stationary increments is
strongly violated. We argue that, for both stationary and nonstationary
increments, Tchebyshev's Theorem provides the basis for constructing emsemble
averages and densities from a single, historic time series if, as in FX
markets, the series shows a definite statistical periodicity on the average.


title: A note on late-time tails of spherical nonlinear waves

abstract:
  We consider the long-time behavior of small amplitude solutions of the
semilinear wave equation $\Box \phi =\phi^p$ in odd $d\geq 5$ spatial
dimensions. We show that for the quadratic nonlinearity ($p=2$) the tail has an
anomalously small amplitude and fast decay. The extension of the results to
more general nonlinearities involving first derivatives is also discussed.


title: Electroweak symmetry breaking in other terms

abstract:
  We analyse descriptions of electroweak symmetry breaking in terms of
ultralocal antisymmetric tensor fields and gauge-singlet geometric variables,
respectively; in particular, the Weinberg--Salam model and, ultimately,
dynamical electroweak symmetry breaking by technicolour theories with enhanced
symmetry groups. Our motivation is to unveil the manifestly gauge invariant
structure of the different realisations. We find, for example, parallels to
different types of torsion.


title: Regularity results for the Primitive Equations of the ocean

abstract:
  We consider the linear Primitive Equations of the ocean in the three
dimensional space, with horizontal periodic and vertical Dirichlet boundary
conditions. Thanks to Fourier transforms we are able to calculate explicitly
the pressure term. We then state existence, unicity and regularity results for
the linear time-depending Primitive Equations, with low-regularity right-hand
side.


title: Controlling transition probability from matter-wave soliton to chaos

abstract:
  For a Bose-Einstein condensate loaded into a weak traveling optical
superlattice it is demonstrated that under a stochastic initial set and in a
given parameter region the solitonic chaos appears with a certain probability.
Effects of the lattice depths and wave vectors on the chaos probability are
investigated analytically and numerically, and different chaotic regions
associated with different chaos probabilities are found. The results suggest a
feasible method for eliminating or strengthening chaos by modulating the moving
superlattice experimentally.


title:
Analysis of the $B\to a_1(1260)$ form-factors with light-cone QCD sum
  rules

abstract:
  In this article, we calculate the $B\to a_1(1260)$ form-factors $V_1(q^2)$,
$V_2(q^2)$, $V_3(q^2)$ and $A(q^2)$ with the $B$-meson light-cone QCD sum
rules. Those form-factors are basic parameters in studying the exclusive
non-leptonic two-body decays $B\to AP$ and semi-leptonic decays $B\to A l
\nu_l$, $B\to A \bar{l}l$. Our numerical results are consistent with the values
from the (light-cone) QCD sum rules. The main uncertainty comes from the
parameter $\omega_0$ (or $\lambda_B$), which determines the shapes of the
two-particle and three-particle light-cone distribution amplitudes of the $B$
meson, it is of great importance to refine this parameter.


title:
Canonical description of D=10 superstring formulated in supertwistor
  space

abstract:
  Canonical description of the D=10 superstring action involving supertwistor
variables generalizing Penrose-Ferber supertwistors is developed. Primary and
secondary constraints are identified and arranged into the first- and
second-class sets. Dirac brackets are introduced and the deformation of the
Poisson bracket algebra of the first-class constraints is studied. The role of
the deformation parameter is played by alpha'.


title:
Delay Time Distribution Measurement of Type Ia Supernovae by the
  Subaru/XMM-Newton Deep Survey and Implications for the Progenitor

abstract:
  The delay time distribution (DTD) of type Ia supernovae (SNe Ia) from star
formation is an important clue to reveal the still unknown progenitor system of
SNe Ia. Here we report on a measurement of the SN Ia DTD in a delay time range
of t_Ia = 0.1-8.0 Gyr by using the faint variable objects detected in the
Subaru/XMM-Newton Deep Survey (SXDS) down to i' ~ 25.5. We select 65 SN
candidates showing significant spatial offset from nuclei of the host galaxies
having old stellar population at z ~ 0.4-1.2, out of more than 1,000 SXDS
variable objects. Although spectroscopic type classification is not available
for these, we quantitatively demonstrate that more than ~80% of these should be
SNe Ia. The DTD is derived using the stellar age estimates of the old galaxies
based on 9 band photometries from optical to mid-infrared wavelength. Combined
with the observed SN Ia rate in elliptical galaxies at the local universe, the
DTD in t_Ia ~ 0.1-10 Gyr is well described by a featureless power-law as
f_D(t_Ia) \propto t_Ia^{-1}. The derived DTD is in excellent agreement with the
generic prediction of the double-degenerate scenario, giving a strong support
to this scenario. In the single-degenerate (SD) scenario, although predictions
by simple analytic formulations have broad DTD shapes that are similar to the
observation, DTD shapes calculated by more detailed binary population synthesis
tend to have strong peaks at characteristic time scales, which do not fit the
observation. This result thus indicates either that the SD channel is not the
major contributor to SNe Ia in old stellar population, or that improvement of
binary population synthesis theory is required. Various sources of systematic
uncertainties are examined and tested, but our main conclusions are not
affected significantly.


title:
Long-term variability of the optical spectra of NGC 4151: I. Light
  curves and flux correlations

abstract:
  Results of a long-term spectral monitoring of the active galactic nucleus of
NGC 4151 are presented (11 years, from 1996 to 2006). High quality spectra
(S/N>50 in the continuum near Halpha and Hbeta) were obtained in the spectral
range ~4000 to 7500 \AA, with a resolution between 5 and 15 A, using the 6-m
and the 1-m SAO's telescopes (Russia), the GHAO's 2.1-m telescope (Cananea,
Mexico), and the OAN-SPM's 2.1-m telescope (San-Pedro, Mexico). The observed
fluxes of the Halpha, Hbeta, Hgamma and HeII emission lines and of the
continuum at the observed wavelength 5117 A, were corrected for the position
angle, the seeing and the aperture effects.
  We found that the continuum and line fluxes varied strongly (up to a factor
6) during the monitoring period. The emission was maximum in 1996-1998, and
there were two minima, in 2001 and in 2005. The Halpha, Hgamma and He II fluxes
were well correlated with the Hbeta flux. We considered three characteristic
periods during which the Hbeta and Halpha profiles were similar: 1996-1999,
2000-2001 and 2002-2006. The line to continuum flux ratios were different; in
particular during the first period, the lines were not correlated with the
continuum and saturated at high fluxes. In the second and third period, where
the continuum flux was small, the Halpha and Hbeta fluxes were well correlated
to the continuum flux, meaning that the ionizing continuum was a good
extrapolation of the optical continuum. The CCFs are often asymmetrical and the
time lags between the lines and the continuum are badly defined indicating the
presence of a complex BLR, with dimensions from 1 to 50 light-days.


title: Hg-Based Superconducting Cuprates: High Tc and Pseudo Spin-Gap

abstract:
  A brief review of microscopic studies of high-Tc superconductors HgBa2CuO4+d
and HgBa2CaCu2O6+d is presented. The topics concerned are the pseudo spin-gap,
the antiferromagnetic spin fluctuations near the quantum critical point, and
the mechanism of the high Tc via NMR. The crystal structure with the flat CuO2
plane, two-dimensional electrical resistivity, Cu NQR, NMR experimental results
are discussed.


title:
Manifestation of a singlet heavy up-type quark in the branching ratios
  of rare decays K to \pi \nu \bar{\nu}, B to \pi \nu \bar{\nu} and B to K \nu
  \bar{\nu}

abstract:
  We investigate the implications of the model with a SU(2)-singlet up-type
quark, heavy enough not to be produced at the LHC, namely, the contribution of
the new quark to the branching ratios of the K to \pi \nu \bar{\nu}, B to \pi
\nu \bar{\nu} and B to K \nu \bar{\nu} decays. We show that the deviation from
the Standard Model can be up to 10% in the case of a 5 TeV quark. Precise
measurements of these branching ratios at the future experiments will allow to
observe the contributions of the new quark or to impose stronger constraints on
its mass.


title: On the Problem of Multiple M2 Branes

abstract:
  A simplified version of 3d BL theory is considered, which allows any number N
of M2 branes in d=11. The underlying 3-algebra structure is provided by
degenerate U(N) Nambu bracket [X,Y,Z] = tr(X) [Y,Z] + tr(Y) [Z,X] + tr(Z)
[X,Y], the corresponding f^{abcd} is not totally antisymmetric and extended
supersymmetry of the action remains to be checked. All the fields, including
auxiliary non-propagating gauge fields, are in adjoint representation of SU(N)
and the only remnant of 3-algebra structure is an octuple of gauge singlets,
acquiring vacuum expectation value in transition to D2 branes in d=10.


title: Anti-commutative Groebner-Shirshov basis of a free Lie algebra

abstract:
  One of the natural ways to prove that the Hall words (Philip Hall, 1933)
consist of a basis of a free Lie algebra is a direct construction: to start
with a linear space spanned by Hall words, to define the Lie product of Hall
words, and then to check that the product yields the Lie identities (Marshall
Hall, 1950). Here we suggest another way using the Composition-Diamond lemma
for free anti-commutative (non-associative) algebras (A.I. Shirshov, 1962).


title: Some remarks for the Akivis algebras and the Pre-Lie algebras

abstract:
  In this paper, by using the Composition-Diamond lemma for non-associative
algebras invented by A. I. Shirshov in 1962, we give Gr\"{o}bner-Shirshov bases
for free Pre-Lie algebras and the universal enveloping non-associative algebra
of an Akivis algebra, respectively. As applications, we show I.P. Shestakov's
result that any Akivis algebra is linear and D. Segal's result that the set of
all good words in $X^{**}$ forms a linear basis of the free Pre-Lie algebra
$PLie(X)$ generated by the set $X$. For completeness, we give the details of
the proof of Shirshov's Composition-Diamond lemma for non-associative algebras.


title: Chernoff and Trotter-Kato theorems for locally convex spaces

abstract:
  We develop new approach for studying the abstract Cauchy problem
$\dot{x}=Ax$, $x(0)=x_0\in D(A)$ for linear operators $A$ defined on a locally
convex space $X$. This approach was firstly introduced in the paper
  "Chernoff and Trotter type product formulas" to study the problem for Banach
spaces.
  In this paper we not only generalize the results of the previous paper to
more general topological spaces but also get new results for Banach spaces. In
particular, we prove the "local" extension of Chernoff-Trotter-Kato type
theorems. Applying this result, we prove Chernoff, Lie-Trotter and Trotter-Kato
theorems for locally convex spaces. Also we find necessary and sufficient
conditions for the validity of the Chernoff and Trotter product formulas.


title: Composition-Diamond Lemma for Modules

abstract:
  In this paper we give some relationships among the Groebner-Shirshov bases in
free associative algebras, free left modules and "double-free" left modules
(free modules over a free algebra). We give the Chibrikov's Composition-Diamond
lemma for modules and show that Kang-Lee's Composition-Diamond lemma follows
from this lemma. As applications, we also deal with highest weight module over
the Lie algebra $sl_2$, Verma module over a Kac-Moody algebra, Verma module
over Lie algebra of coefficients of a free conformal algebra and the universal
enveloping module for a Sabinin algebra.


title: Edge-dependent selection rules in magic triangular graphene flakes

abstract:
  The electronic shell and supershell structure of triangular graphene quantum
dots has been studied using density functional and tight-binding methods. The
density functional calculations demonstrate that the electronic structure close
to the Fermi energy is correctly described with a simple tight-binding model
where only the p_z orbitals perpendicular to the graphene layer are included.
The results show that (i) both at the bottom and at the top of the p_z band a
supershell structure similar to that of free electrons confined in a triangular
cavity is seen, (ii) close to the Fermi level the shell structure is that of
free massless particles, (iii) triangles with armchair edges show an additional
sequence of levels ('ghost states') absent for triangles with zigzag edges
while the latter exhibit edge states, and (iv) the observed shell structure is
rather insensitive to the edge roughness.


title: Structural Dynamics of Various Causes of Migration in Jaipur

abstract:
  Various social causes for migration in Jaipur are studied and statistical
hypotheses are made in this paper.


title: Linear projections and successive minima

abstract:
  Using linear projections one gets new inequalities for the successive minima
of the lattice of sections of an hermitian line bundle on an arithmetic
surface.


title: Simplified Langevin approach to the Peyrard-Bishop-Dauxois model of DNA

abstract:
  A simple Langevin approach is used to study stationary properties of the
Peyrard-Bishop-Dauxois model for DNA, allowing known properties to be recovered
in an easy way. Results are shown for the denaturation transition in
homogeneous samples, for which some implications, so far overlooked, of an
analogy with equilibrium wetting transitions are highlighted. This analogy
implies that the order-parameter, asymptotically, exhibits a second order
transition even if it may be very abrupt for non-zero values of the stiffness
parameter. Not surprisingly, we also find that for heterogeneous DNA, within
this model the largest bubbles in the pre-melting stage appear in
adenine-thymine rich regions, while we suggest the possibility of some sort of
not strictly local effects owing to the merging of bubbles.


title:
Representations of pointed Hopf algebras and their Drinfel'd quantum
  doubles

abstract:
  We study representations of nilpotent type nontrivial liftings of quantum
linear spaces and their Drinfel'd quantum doubles. We construct a family of
Verma- type modules in both cases and prove a parametrization theorem for
simple modules. We compute the Loewy and socle series of Verma modules under a
mild restriction on the datum of a lifting. We find bases and dimensions of
simple modules.


title: Linear Koszul Duality

abstract:
  In this paper we construct, for F_1 and F_2 subbundles of a vector bundle E,
a "Koszul duality" equivalence between derived categories of G_m-equivariant
coherent (dg-)sheaves on the derived intersection of F_1 and F_2 inside E, and
the corresponding derived intersection of the orthogonals of F_1 and F_2 inside
the dual vector bundle E^*. We also propose applications to Hecke algebras.


title:
A Unified Semi-Supervised Dimensionality Reduction Framework for
  Manifold Learning

abstract:
  We present a general framework of semi-supervised dimensionality reduction
for manifold learning which naturally generalizes existing supervised and
unsupervised learning frameworks which apply the spectral decomposition.
Algorithms derived under our framework are able to employ both labeled and
unlabeled examples and are able to handle complex problems where data form
separate clusters of manifolds. Our framework offers simple views, explains
relationships among existing frameworks and provides further extensions which
can improve existing algorithms. Furthermore, a new semi-supervised
kernelization framework called ``KPCA trick'' is proposed to handle non-linear
problems.


title: Computing ODE Symmetries as Abnormal Variational Symmetries

abstract:
  We give a new computational method to obtain symmetries of ordinary
differential equations. The proposed approach appears as an extension of a
recent algorithm to compute variational symmetries of optimal control problems
[Comput. Methods Appl. Math. 5 (2005), no. 4, pp. 387-409], and is based on the
resolution of a first order linear PDE that arises as a necessary and
sufficient condition of invariance for abnormal optimal control problems. A
computer algebra procedure is developed, which permits to obtain ODE symmetries
by the proposed method. Examples are given, and results compared with those
obtained by previous available methods.


title: Model Bulding for the Neutrino Sector and Cold Dark Matter

abstract:
  It is now clear that the masses of the neutrino sector are much lighter than
those of the other three sectors.There are many attempts to explain the
neutrino masses radiatively by means of inert Higgses, which don't have vacuum
expectation values. Then one can discuss cold dark matter candidates, because
of no needing so heavy particles and having a $Z_2$ parity symmetry
corresponding to the R-parity symmetry of the MSSM. The most famous work would
be the Zee model. Recently a new type model along this line of thought was
proposed by E. Ma. We introduce a flavor symmetry based on a dihedral group
$D_6$ to constrain the Yukawa sector. For the neutrino sector, we find that the
maximal mixing of atmospheric neutrinos is realized, it can also be shown that
only an inverted mass spectrum, the value of $|V_{MNS_{13}}|$ is 0.0034 and so
on. For the fermionic CDM candidates, we find that the mass of the CDM and the
inert Higgs should be larger than about 230 and 300 GeV, respectively. If we
restrict ourselves to a perturbative regime, they should be lighter than about
750 GeV.


title: Mod-2 Equivalence of the K-theoretic Euler and Signature Classes

abstract:
  This note proves that, as K-theory elements, the symbol classes of the de
Rham operator and the signature operator on a closed manifold of even dimension
are congruent mod 2. An equivariant generalization is given pertaining to the
equivariant Euler characteristic and the multi-signature.


title: Electromagnetic radiation by gravitating bodies

abstract:
  Gravitating bodies in motion, regardless of their constitution, always
produce electromagnetic radiation in the form of photon pairs. This phenomenon
is an analog of the radiation caused by the motion of dielectric (or magnetic)
bodies. It is a member of a wide class of phenomena named dynamical Casimir
effects, and it may be viewed as the squeezing of the electromagnetic vacuum.
Production of photon pairs is a purely quantum-mechanical effect.
Unfortunately, as we show, the emitted radiation is extremely weak as compared
to radiation produced by other mechanisms.


title: Carbon nanotube-sharp tips and carbon nanotube-soldering irons

abstract:
  We report on the nano-electron beam assisted fabrication of atomically sharp
iron-based tips and on the creation of a nano-soldering iron for
nano-interconnects using Fe-filled multiwalled carbon nanotubes (MWCNTs). High
energy electron beam machining has been proven a powerful tool to modify
desired nanostructures for technological applications and to form molecular
junctions and interconnections between carbon nanotubes. Recent studies showed
the high degree of complexity in the creation of direct interconnections
between multiwalled and CNTs having dissimilar diameters. Our technique allows
for carving a MWCNT into a nanosoldering iron that was demonstrated capable of
joining two separated halves of a tube. This approach could easily be extended
to the interconnection of two largely dissimilar CNTs, between a CNT and a
nanowire or between two nanowires.


title: The Branch Locus for One-Dimensional Pisot Tiling Spaces

abstract:
  If phi is a Pisot substitution of degree d, then the inflation and
substitution homeomorphism Phi on the tiling space T_Phi factors via geometric
realization onto a d-dimensional solenoid. Under this realization, the
collection of Phi-periodic asymptotic tilings corresponds to a finite set that
projects onto the branch locus in a d-torus. We prove that if two such tiling
spaces are homeomorphic, then the resulting branch loci are the same up to the
action of certain affine maps on the torus.


title: Non-abelian statistics from an abelian model

abstract:
  It is well known that the abelian $Z_2$ anyonic model (toric code) can be
realized on a highly entangled two-dimensional spin lattice, where the anyons
are quasiparticles located at the endpoints of string-like concatenations of
Pauli operators. Here we show that the same entangled states of the same
lattice are capable of supporting the non-abelian Ising model, where the
concatenated operators are elements of the Clifford group. The Ising anyons are
shown to be essentially superpositions of the abelian toric code anyons,
reproducing the required fusion, braiding and statistical properties. We
propose a string framing and ancillary qubits to implement the non-trivial
chirality of this model.


title: Stochastic evolution equations in UMD Banach spaces

abstract:
  We discuss existence, uniqueness, and space-time H\"older regularity for
solutions of the parabolic stochastic evolution equation dU(t) = (AU(t) +
F(t,U(t))) dt + B(t,U(t)) dW_H(t), t\in [0,\Tend], U(0) = u_0, where $A$
generates an analytic $C_0$-semigroup on a UMD Banach space $E$ and $W_H$ is a
cylindrical Brownian motion with values in a Hilbert space $H$. We prove that
if the mappings $F:[0,T]\times E\to E$ and $B:[0,T]\times E\to
\mathscr{L}(H,E)$ satisfy suitable Lipschitz conditions and $u_0$ is
$\F_0$-measurable and bounded, then this problem has a unique mild solution,
which has trajectories in $C^\l([0,T];\D((-A)^\theta)$ provided $\lambda\ge 0$
and $\theta\ge 0$ satisfy $\l+\theta<\frac12$. Various extensions of this
result are given and the results are applied to parabolic stochastic partial
differential equations.


title: On Birational Transformations of Pairs in the Complex Plane

abstract:
  This article deals with the study of the birational transformations of the
projective complex plane which leave invariant an irreducible algebraic curve.
We try to describe the state of art and provide some new results on this
subject.


title:
Analysis of Discrete and Hybrid Stochastic Systems by Nonlinear
  Contraction Theory

abstract:
  We investigate the stability properties of discrete and hybrid stochastic
nonlinear dynamical systems. More precisely, we extend the stochastic
contraction theorems (which were formulated for continuous systems) to the case
of discrete and hybrid resetting systems. In particular, we show that the mean
square distance between any two trajectories of a discrete (or hybrid
resetting) contracting stochastic system is upper-bounded by a constant after
exponential transients. Using these results, we study the synchronization of
noisy nonlinear oscillators coupled by discrete noisy interactions.


title:
Large sets with small doubling modulo p are well covered by an
  arithmetic progression

abstract:
  We prove that there is a small but fixed positive integer e such that for
every prime larger than a fixed integer, every subset S of the integers modulo
p which satisfies |2S|<(2+e)|S| and 2(|2S|)-2|S|+2 < p is contained in an
arithmetic progression of length |2S|-|S|+1. This is the first result of this
nature which places no unnecessary restrictions on the size of S.


title: Cache-Oblivious Selection in Sorted X+Y Matrices

abstract:
  Let X[0..n-1] and Y[0..m-1] be two sorted arrays, and define the mxn matrix A
by A[j][i]=X[i]+Y[j]. Frederickson and Johnson gave an efficient algorithm for
selecting the k-th smallest element from A. We show how to make this algorithm
IO-efficient. Our cache-oblivious algorithm performs O((m+n)/B) IOs, where B is
the block size of memory transfers.


title: Issues in Strategic Decision Modelling

abstract:
  [Spreadsheet] Models are invaluable tools for strategic planning. Models help
key decision makers develop a shared conceptual understanding of complex
decisions, identify sensitivity factors and test management scenarios.
Different modelling approaches are specialist areas in themselves. Model
development can be onerous, expensive, time consuming, and often bewildering.
It is also an iterative process where the true magnitude of the effort, time
and data required is often not fully understood until well into the process.
This paper explores the traditional approaches to strategic planning modelling
commonly used in organisations and considers the application of a real-options
approach to match and benefit from the increasing uncertainty in today's
rapidly changing world.


title: Recovery of inhomogeneities and buried obstacles

abstract:
  In this paper we consider the unique determination of inhomogeneities
together with possible buried obstacles by scattering measurements. Under the
assumption that the buried obstacles have only planar contacts with the
inhomogeneities, we prove that one can recover both of them by knowing the
associated scattering amplitude at a fixed energy.


title: A ring laser gyroscope without lock-in phenomenon

abstract:
  We theoretically and numerically study the effect of backscattering on
rotating ring lasers by employing the Maxwell-Bloch equations. We show that
frequency shifts due to the Sagnac effect incorporating the effect of
backscattering can be observed without lock-in phenomenon, if the strength of
backscattering originating in the bumps of the refractive index is larger than
a certain value. It is also shown that the experimental results corresponding
to the theoretical ones can actually be obtained by using a semiconductor
fiber-optic ring laser gyroscope.


title: Optimum Binary Search Trees on the Hierarchical Memory Model

abstract:
  The Hierarchical Memory Model (HMM) of computation is similar to the standard
Random Access Machine (RAM) model except that the HMM has a non-uniform memory
organized in a hierarchy of levels numbered 1 through h. The cost of accessing
a memory location increases with the level number, and accesses to memory
locations belonging to the same level cost the same. Formally, the cost of a
single access to the memory location at address a is given by m(a), where m: N
-> N is the memory cost function, and the h distinct values of m model the
different levels of the memory hierarchy.
  We study the problem of constructing and storing a binary search tree (BST)
of minimum cost, over a set of keys, with probabilities for successful and
unsuccessful searches, on the HMM with an arbitrary number of memory levels,
and for the special case h=2.
  While the problem of constructing optimum binary search trees has been well
studied for the standard RAM model, the additional parameter m for the HMM
increases the combinatorial complexity of the problem. We present two dynamic
programming algorithms to construct optimum BSTs bottom-up. These algorithms
run efficiently under some natural assumptions about the memory hierarchy. We
also give an efficient algorithm to construct a BST that is close to optimum,
by modifying a well-known linear-time approximation algorithm for the RAM
model. We conjecture that the problem of constructing an optimum BST for the
HMM with an arbitrary memory cost function m is NP-complete.


title: Reducing Overconfidence in Spreadsheet Development

abstract:
  Despite strong evidence of widespread errors, spreadsheet developers rarely
subject their spreadsheets to post-development testing to reduce errors. This
may be because spreadsheet developers are overconfident in the accuracy of
their spreadsheets. This conjecture is plausible because overconfidence is
present in a wide variety of human cognitive domains, even among experts. This
paper describes two experiments in overconfidence in spreadsheet development.
The first is a pilot study to determine the existence of overconfidence. The
second tests a manipulation to reduce overconfidence and errors. The
manipulation is modestly successful, indicating that overconfidence reduction
is a promising avenue to pursue.


title: Spacetime Meshing for Discontinuous Galerkin Methods

abstract:
  Spacetime discontinuous Galerkin (SDG) finite element methods are used to
solve such PDEs involving space and time variables arising from wave
propagation phenomena in important applications in science and engineering.
  To support an accurate and efficient solution procedure using SDG methods and
to exploit the flexibility of these methods, we give a meshing algorithm to
construct an unstructured simplicial spacetime mesh over an arbitrary
simplicial space domain. Our algorithm is the first spacetime meshing algorithm
suitable for efficient solution of nonlinear phenomena in anisotropic media
using novel discontinuous Galerkin finite element methods for implicit
solutions directly in spacetime. Given a triangulated d-dimensional Euclidean
space domain M (a simplicial complex) and initial conditions of the underlying
hyperbolic spacetime PDE, we construct an unstructured simplicial mesh of the
(d+1)-dimensional spacetime domain M x [0,infinity). Our algorithm uses a
near-optimal number of spacetime elements, each with bounded temporal aspect
ratio for any finite prefix M x [0,T] of spacetime. Our algorithm is an
advancing front procedure that constructs the spacetime mesh incrementally, an
extension of the Tent Pitcher algorithm of Ungor and Sheffer (2000).
  In 2DxTime, our algorithm simultaneously adapts the size and shape of
spacetime tetrahedra to a spacetime error indicator. We are able to incorporate
more general front modification operations, such as edge flips and limited mesh
smoothing. Our algorithm represents recent progress towards a meshing algorithm
in 2DxTime to track moving domain boundaries and other singular surfaces such
as shock fronts.


title: The Wall and The Ball: A Study of Domain Referent Spreadsheet Errors

abstract:
  The Cell Error Rate in simple spreadsheets averages about 2% to 5%. This CER
has been measured in domain free environments. This paper compares the CERs
occurring in domain free and applied domain tasks. The applied domain task
requires the application of simple linear algebra to a costing problem. The
results show that domain referent knowledge influences participants' approaches
to spreadsheet creation and spreadsheet usage. The conclusion is that
spreadsheet error making is influenced by domain knowledge and domain
perception. Qualitative findings also suggest that spreadsheet error making is
a part of overall human behaviour, and ought to be analyzed against this wider
canvas.


title: A non-commutative generalization of $k$-Schur functions

abstract:
  We introduce non-commutative analogues of $k$-Schur functions of
Lapointe-Lascoux and Morse. We give an explicit formulas for the expansions of
non-commutive functions with one and two parameters in terms of these new
functions. These results are similar to the conjectures existing in the
commutative case.


title: Casimir Energy of 5D Electro-Magnetism and Sphere Lattice Regularization

abstract:
  Casimir energy is calculated in the 5D warped system. It is compared with the
flat one. The position/ momentum propagator is exploited. A new regularization,
called {\it sphere lattice regularization}, is introduced. It is a direct
realization of the geometrical interpretation of the renormalization group. The
regularized configuration is closed-string like. We do {\it not} take the
KK-expansion approach. Instead the P/M propagator is exploited, combined with
the heat-kernel method. All expressions are closed-form (not KK-expanded form).
Rigorous quantities are only treated (non-perturbative treatment). The properly
regularized form of Casimir energy, is expressed in the closed form. We
numerically evaluate its $\La$(4D UV-cutoff), $\om$(5D bulk curvature,
warpedness parameter) and $T$(extra space IR parameter) dependence.


title: Efficient Spacetime Meshing with Nonlocal Cone Constraints

abstract:
  Spacetime Discontinuous Galerkin (DG) methods are used to solve hyperbolic
PDEs describing wavelike physical phenomena. When the PDEs are nonlinear, the
speed of propagation of the phenomena, called the wavespeed, at any point in
the spacetime domain is computed as part of the solution. We give an advancing
front algorithm to construct a simplicial mesh of the spacetime domain suitable
for DG solutions. Given a simplicial mesh of a bounded linear or planar space
domain M, we incrementally construct a mesh of the spacetime domain M x
[0,infinity) such that the solution can be computed in constant time per
element. We add a patch of spacetime elements to the mesh at every step. The
boundary of every patch is causal which means that the elements in the patch
can be solved immediately and that the patches in the mesh are partially
ordered by dependence. The elements in a single patch are coupled because they
share implicit faces; however, the number of elements in each patch is bounded.
The main contribution of this paper is sufficient constraints on the progress
in time made by the algorithm at each step which guarantee that a new patch
with causal boundary can be added to the mesh at every step even when the
wavespeed is increasing discontinuously. Our algorithm adapts to the local
gradation of the space mesh as well as the wavespeed that most constrains
progress at each step. Previous algorithms have been restricted at each step by
the maximum wavespeed throughout the entire spacetime domain.


title: The Dynkin diagram cohomology of finite Coxeter groups

abstract:
  Let D be a connected graph. The Dynkin complex CD(A) of a D-algebra A was
introduced by the second author in [TL2] to control the deformations of
quasi-Coxeter algebra structures on A. In the present paper, we study the
cohomology of this complex when A is the group algebra of a Coxeter group W and
D is the Dynkin diagram of W. We compute this cohomology when W is finite and
prove in particular the rigidity of quasi-Coxeter algebra structures on kW. For
an arbitrary W, we compute the top cohomology group and obtain a number of
additional partial results when W is affine. Our computations are carried out
by filtering CD(A) by the number of vertices of subgraphs of D. The
corresponding graded complex turns out to be dual to the sum of the Coxeter
complexes of all standard, irreducible parabolic subgroups of W.


title:
Teleparallel Version of the Levi-Civita Vacuum Solutions and their
  Energy Contents

abstract:
  In this paper, we find the teleparallel version of the Levi-Civita metric and
obtain tetrad and the torsion fields. The tensor, vector and the axial-vector
parts of the torsion tensor are evaluated. It is found that the vector part
lies along the radial direction only while the axial-vector vanishes everywhere
because the metric is diagonal. Further, we use the teleparallel version of
M$\ddot{o}$ller, Einstein, Landau-Lifshitz and Bergmann-Thomson prescriptions
to find the energy-momentum distribution of this metric and compare the results
with those already found in General Relativity. It is worth mentioning here
that momentum is constant in both the theories for all the prescriptions. The
energy in teleparallel theory is equal to the corresponding energy in GR only
in M$\ddot{o}$ller prescription for the remaining prescriptions, the energy do
not agree in both theories. We also conclude that M$\ddot{o}$ller's
energy-momentum distribution is independent of the coupling constant $\lambda$
in the teleparallel theory.


title:
Double heavy-quarkonium production from electron-positron annihilation
  in the Bethe-Salpeter formalism

abstract:
  In this work we evaluate the cross section of the process $e^+e^-\to J/\psi
\eta_c$ at energy $\sqrt{s}\approx 10.6$ GeV in the Bethe-Salpeter formalism.
To simplify our calculation, the heavy quark limit is employed. Without taking
the beyond-leading-order contribution(s) into account, the cross section
calculated in this scenario is comparable with the experimental data. We also
present our prediction for the cross section of double bottomonium production
$e^+e^-\to \Upsilon(1S)\eta_b$ for the energy range of $\sqrt{s}\approx (25
\hbox{-} 30)$ GeV which may be experimentally tested, even though there is no
facility of this range available at present yet.


title: Nuclear-resonant electron scattering

abstract:
  We investigate nuclear-resonant electron scattering as occurring in the
two-step process of nuclear excitation by electron capture (NEEC) followed by
internal conversion. The nuclear excitation and decay are treated by a
phenomenological collective model in which nuclear states and transition
probabilities are described by experimental parameters. We present capture
rates and resonant strengths for a number of heavy ion collision systems
considering various scenarios for the resonant electron scattering process. The
results show that for certain cases resonant electron scattering can have
significantly larger resonance strengths than NEEC followed by the radiative
decay of the nucleus. We discuss the impact of our findings on the possible
experimental observation of NEEC.


title: Lectures on Scattering Amplitudes via AdS/CFT

abstract:
  We review recent progress on computing scattering amplitudes of planar N=4
super Yang-Mills at strong coupling by using the AdS/CFT duality. We do
explicit computations by using both, dimensional regularization and a cut-off
in the radial direction. Up to an additive constant independent on the
kinematics, the finite piece of the amplitude is the same in both
regularizations. The later scheme is particularly appropriate for understanding
the conformal properties of the amplitudes.


title: Enrichment of lead (Pb) in the Galactic halo

abstract:
  We have determined lead (Pb) abundances for twelve red giants having [Fe/H]
between -2.1 and -1.3, and its upper-limits for two lower metallicity objects,
as well as the abundances of lanthanum (La) and europium (Eu). The averages of
[Pb/Fe] and [Pb/Eu] are -0.3 and -0.6, respectively, and no clear increase of
these ratios with increasing metallicity is found. The [La/Eu] values are only
slightly higher than that of the r-process component in solar-system material.
Combining the previous studies for globular clusters, these results suggest
little contribution of the s-process to Pb of the field stars studied here,
supporting the estimate of Pb production by the r-process from the solar-system
abundances.