title:
Lineability of the set of bounded linear non-absolutely summing
  operators

abstract:
  In this note we solve, except for extremely pathological cases, a question
posed by Puglisi and Seoane-Sepulveda on the lineability of the set of bounded
non-absolutely summing linear operators. We also show how the idea of the proof
can be adapted to several related situations.


title: Universality of Crystallographic Pinning

abstract:
  We study traveling waves for reaction diffusion equations on the spatially
discrete domain $\Z^2$. The phenomenon of crystallographic pinning occurs when
traveling waves become pinned in certain directions despite moving with
non-zero wave speed in nearby directions. Mallet-Paret has shown that
crystallographic pinning occurs for all rational directions, so long as the
nonlinearity is close to the sawtooth. In this paper we show that
crystallographic pinning holds in the horizontal and vertical directions for
bistable nonlinearities which satisfy a specific computable generic condition.
The proof is based on dynamical systems. In particular, it relies on an
examination of the heteroclinic chains which occur as singular limits of wave
profiles on the boundary of the pinning region.


title:
Synthesis and Microstructural Studies of Iron Oxypnictide LaO1-xFxFeAs
  Superconductors

abstract:
  We report on the synthesis and structural/ microstructural studies of iron
based fluorine doped LaOFeAs superconductors. We have successfully synthesized
fluorine doped superconducting LaO1-xFxFeAs materials by choosing lower
temperature (1150^0C) and longer synthesis duration (60 hours) as compared to
the standard values of these employed in the pioneering first contribution
[Kamihara et al 2008 J Am Chem Soc 130 3296]. Decrease of lattice parameters as
determined by x-ray diffraction confirm the substitution of fluorine. The
superconducting transition temperature is 27.5 K which is observed at doping
level of x=0.2. This superconducting material LaO1-xFxFeAs exhibits interesting
microstructural characteristic. This relates to the existence of another
structural phase, besides the standard phase, having c parameters of ~12.67A.
This suggests existence of modulated structure, similar to the cuprates, in
these new oxypnictides. This phase may have new impacts on this new high-Tc
family.


title: Quantum symmetries and quantum isometries of compact metric spaces

abstract:
  We prove that a compact quantum group with faithful Haar state which has a
faithful action on a compact space must be a Kac algebra, with bounded antipode
and the square of the antipode being identity. The main tool in proving this is
the theory of ergodic quantum group action on $C^*$ algebras.
  Using the above fact, we also formulate a definition of isometric action of a
compact quantum group on a compact metric space, generalizing the definition
given by Banica for finite metric spaces, and prove for certain special class
of metric spaces the existence of the universal object in the category of those
compact quantum groups which act isometrically and are `bigger' than the
classical isometry group.


title:
Auroral evidence for multiple reconnection in the magnetospheric tail
  plasma sheet

abstract:
  We present auroral evidence for multiple and, most probably, small scale
reconnection in the near Earth magnetospheric plasma sheet current layer during
auroral activity. Hall currents as the source of upward and downward
field-aligned currents require generation of the corresponding electron fluxes.
The auroral spatial ordering in a multiple sequence of these fluxes requires
the assumption of the existence of several -- and possibly -- even many
tailward reconnection sites.


title: The Number Of Magnetic Null Points In The Quiet Sun Corona

abstract:
  The coronal magnetic field above a particular photospheric region will vanish
at a certain number of points, called null points. These points can be found
directly in a potential field extrapolation or their density can be estimated
from Fourier spectrum of the magnetogram. The spectral estimate, which assumes
that the extrapolated field is random, homogeneous and has Gaussian statistics,
is found here to be relatively accurate for quiet Sun magnetograms from SOHO's
MDI. The majority of null points occur at low altitudes, and their distribution
is dictated by high wavenumbers in the Fourier spectrum. This portion of the
spectrum is affected by Poisson noise, and as many as five-sixths of null
points identified from a direct extrapolation can be attributed to noise. The
null distribution above 1500 km is found to depend on wavelengths that are
reliably measured by MDI in either its low-resolution or high-resolution mode.
After correcting the spectrum to remove white noise and compensate for the
modulation transfer function we find that a potential field extrapolation
contains, on average, one magnetic null point, with altitude greater than 1.5
Mm, above every 322 square Mm patch of quiet Sun. Analysis of 562 quiet Sun
magnetograms spanning the two latest solar minimum shows that the null point
density is relatively constant with roughly 10% day-to-day variation. At
heights above 1.5 Mm, the null point density decreases approximately as the
inverse cube of height. The photospheric field in the quiet Sun is well
approximated as that from discrete elements with mean flux 1.0e19 Mx
distributed randomly with density n=0.007 per square Mm.


title:
A Criterion for the Viability of Stochastic Semilinear Control Systems
  via the Quasi-Tangency Condition

abstract:
  In this paper we study a criterion for the viability of stochastic semilinear
control systems on a real, separable Hilbert space. The necessary and
sufficient conditions are given using the notion of stochastic quasi-tangency.
As a consequence, we prove that approximate viability and the viability
property coincide for stochastic linear control systems. We obtain Nagumo's
stochastic theorem and we present a method allowing to provide explicit
criteria for the viability of smooth sets. We analyze the conditions
characterizing the viability of the unit ball. The paper generalizes recent
results from the deterministic framework.


title: Can Dark Matter Decay in Dark Energy?

abstract:
  We analyze the interaction between Dark Energy and Dark Matter from a
thermodynamical perspective. By assuming they have different temperatures, we
study the possibility of occurring a decay from Dark Matter into Dark Energy,
characterized by a negative parameter $Q$. We find that, if at least one of the
fluids has non vanishing chemical potential, for instance $\mu_x<0$ and
$\mu_{dm}=0$ or $\mu_x=0$ and $\mu_{dm}>0$, the decay is possible, where
$\mu_x$ and $\mu_{dm}$ are the chemical potentials of Dark Energy and Dark
Matter, respectively. Using recent cosmological data, we find that, for a
fairly simple interaction, the Dark Matter decay is favored with a probability
of $\sim 93%$ over the Dark Energy decay. This result comes from a likelihood
analysis where only background evolution has been considered.


title:
H^1 and BMO for certain locally doubling metric measure spaces of finite
  measure

abstract:
  In a previous paper the authors developed a H^1-BMO theory for unbounded
metric measure spaces $(M,\rho,m)$ of infinite measure that are locally
doubling and satisfy two geometric properties, called "approximate midpoint"
property and "isoperimetric" property. In this paper we develop a similar
theory for spaces of finite measure. We prove that all the results that hold in
the infinite measure case have their counterparts in the finite measure case.
Finally, we show that the theory applies to a class of unbounded, complete
Riemannian manifolds of finite measure and to a class of metric measure spaces
of the form (R^n,\rho_\phi, m_\phi), where dm_\phi=e^{-\phi} dx and \rho_\phi$
is the Riemannian metric corresponding to the length element ds^2=(1+
|grad\phi|)^2(dx_1^2+...+dx_n^2)$. This generalizes previous work of the last
two authors for the Gauss space.


title:
Signature of Martensite transformation on conductivity noise in thin
  films of NiTi shape memory alloys

abstract:
  Slow time-dependent fluctuations, or noise, in the electrical resistance of
dc magnetron sputtered thin films of Nickel Titanium shape memory alloys have
been measured. Even in equilibrium, the noise was several orders of magnitude
larger than that of simple diffusive metallic films, and was found to be
non-monotonic around the martensitic transformation regime. The results are
discussed in terms of dynamics of structural defects, which also lay foundation
to a new noise-based characterization scheme of martensite transformation.


title: Criticality of tuning in athermal phase transitions

abstract:
  We experimentally address the importance of tuning in athermal phase
transitions, which are triggered only by a slowly varying external field acting
as tuning parameter. Using higher order statistics of fluctuations, a singular
critical instability is detected for the first time in spite of an apparent
universal self-similar kinetics over a broad range of driving force. The
results as well as the experimental technique are likely to be of significance
to many slowly driven non-equilibrium systems from geophysics to material
science which display avalanche dynamics.


title: Computing the Newton polygon of the implicit equation

abstract:
  We consider polynomially and rationally parameterized curves, where the
polynomials in the parameterization have fixed supports and generic
coefficients. We apply sparse (or toric) elimination theory in order to
determine the vertex representation of its implicit polygon, i.e. of the
implicit equation's Newton polygon. In particular, we consider mixed
subdivisions of the input Newton polygons and regular triangulations of point
sets defined by Cayley's trick. We distinguish polynomial and rational
parameterizations, where the latter may have the same or different
denominators; the implicit polygon is shown to have, respectively, up to 4, 5,
or 6 vertices.


title:
Estimates for functions of the Laplacian on manifolds with bounded
  geometry

abstract:
  In this paper we consider a complete connected noncompact Riemannian manifold
M with Ricci curvature bounded from below and positive injectivity radius.
Denote by L the Laplace-Beltrami operator on M. We assume that the kernel
associated to the heat semigroup generated by L satisfies a mild decay
condition at infinity. We prove that if m is a bounded holomorphic function in
a suitable strip of the complex plane, and satisfies Mihlin-Hormander type
conditions of appropriate order at infinity, then the operator m(L) extends to
an operator of weak type 1.
  This partially extends a celebrated result of J. Cheeger, M. Gromov and M.
Taylor, who proved similar results under much stronger curvature assumptions on
M, but without any assumption on the decay of the heat kernel.


title: Very slow surface plasmons: theory and practice

abstract:
  The paper is of a methodological character and has as a goal to give a brief
description of the concept of theory and practical application of very slow
optical plasmons. They exist on the metal-dielectric boundaries, namely, on
very thin metal films and fibers and as standing waves on metal spheres and
ellipsoids. The material presented in the paper features by widening the common
concepts of electromagnetic modes of various spaces, of the probability of
spontaneous emission, of creation of optical images, of the limits of optical
focusing, and of the photon linear momentum. All mentioned studies are
completed in recent years. The problem of the photon momentum in a dielectric
medium was the topic of irreconcilable disputes for 100 years starting in the
time of appearing of Minkowski and Abraham famous papers. Various practical
applications are surveyed: the experiments with a great intensification of an
atom spontaneous emission into a plasmonic field mode of a metal nanoparticle,
the experiments on focusing optical radiation into a spot that substantially
smaller than a diffraction limited spot, a so called near perfect Pendry lens
that produces the image with details that substantially smaller than defined by
diffraction, and lastly, the concept of hundredfold and more magnification of a
photon mechanical linear momentum in a plasmon. The work completed is supported
by RFBR, grants Nos 05-02-19647, 07-02-01328.


title:
Entire solutions to equivariant elliptic systems with variational
  structure

abstract:
  In the present paper we consider the system {\Delta}u - W_u (u) = 0, where u:
R^n to R^n, for a class of potentials W: R^n to R that possess several global
minima and are invariant under a general finite reflection group G. We
establish existence of nontrivial entire solutions connecting the global minima
of W along certain directions at infinity.


title:
Low temperature thermal conductivity in a d-wave superconductor with
  coexisting charge order: Effect of self-consistent disorder and vertex
  corrections

abstract:
  Given the experimental evidence of charge order in the underdoped cuprate
superconductors, we consider the effect of coexisting charge order on
low-temperature thermal transport in a d-wave superconductor. Using a
phenomenological Hamiltonian that describes a two-dimensional system in the
presence of a Q=(\pi,0) charge density wave and d-wave superconducting order,
and including the effects of weak impurity scattering, we compute the
self-energy of the quasiparticles within the self-consistent Born
approximation, and calculate the zero-temperature thermal conductivity using
linear response formalism. We find that vertex corrections within the ladder
approximation do not significantly modify the bare-bubble result that was
previously calculated. However, self-consistent treatment of the disorder does
modify the charge-order-dependence of the thermal conductivity tensor, in that
the magnitude of charge order required for the system to become effectively
gapped is renormalized, generally to a smaller value.


title: Thermalization process of a photo-generated plasma in semiconductors

abstract:
  The kinetics of ultra-fast processes which leads to the thermalization
condition of a photo-excited plasma in semiconductor systems is studied
theoretically. We analyze the time evolution of a carrier population generated
by a finite optical pulse, from the beginning of the pulse until the time in
which the carrier population reaches a quasi-equilibrium condition. We
calculate the energy fluxes caused by the main interaction mechanisms along the
different stages the system passes through. Our analysis is done by using a set
of non-linear rate equations which govern the time evolution of the carrier
population in the energy space. We consider the main interaction mechanisms,
including dynamic screening and phonon population effects.


title: Stability of invariant measures

abstract:
  We generalize various notions of stability of invariant sets of dynamical
systems to invariant measures, by defining a topology on the set of measures.
The defined topology is similar, but not topologically equivalent to weak*
topology, and it also differs from topologies induced by the Riesz
Representation Theorem. It turns out that the constructed topology is a
solution of a limit case of a $p$-optimal transport problem, for $p=\infty$.


title:
Multicomponent Burgers and KP Hierarchies, and Solutions from a Matrix
  Linear System

abstract:
  Via a Cole-Hopf transformation, the multicomponent linear heat hierarchy
leads to a multicomponent Burgers hierarchy. We show in particular that any
solution of the latter also solves a corresponding multicomponent (potential)
KP hierarchy. A generalization of the Cole-Hopf transformation leads to a more
general relation between the multicomponent linear heat hierarchy and the
multicomponent KP hierarchy. From this results a construction of exact
solutions of the latter via a matrix linear system.


title: E/B mode mixing

abstract:
  In future microwave background polarization experiments, particularly those
that aim to characterize the B component, careful attention will have to be
paid to the mixing of E and B components due to finite sky coverage and
pixelization. Any polarization map can be decomposed into "pure E," "pure B,"
and "ambiguous" components. In practice, since the B component is expected to
be much weaker than the E component, nearly all of the recoverable $B$
information is contained in the pure B component. The amount of B information
lost to ambiguous modes can be estimated in simple ways from the survey
geometry and pixelization. Separation of any given map into pure and ambiguous
components can be done by finding a basis of pure and ambiguous modes, but it
is often more efficient to "purify" the map directly in real space by solving a
certain differential equation to find the ambiguous component. This method may
be useful in conjunction with power spectrum estimation techniques such as the
pseudo-Cl method.


title: The existence of time

abstract:
  Of those gauge theories of gravity known to be equivalent to general
relativity, only the biconformal gauging introduces new structures - the
quotient of the conformal group of any pseudo-Euclidean space by its Weyl
subgroup always has natural symplectic and metric structures. Using this metric
and symplectic form, we show that there exist canonically conjugate,
orthogonal, metric submanifolds if and only if the original gauged space is
Euclidean or signature 0. In the Euclidean cases, the resultant configuration
space must be Lorentzian. Therefore, in this context, time may be viewed as a
derived property of general relativity.


title: A Bayesian Framework for Opinion Updates

abstract:
  Opinion Dynamics lacks a theoretical basis. In this article, I propose to use
a decision-theoretic framework, based on the updating of subjective
probabilities, as that basis. We will see we get a basic tool for a better
understanding of the interaction between the agents in Opinion Dynamics
problems and for creating new models. I will review the few existing
applications of Bayesian update rules to both discrete and continuous opinion
problems and show that several traditional models can be obtained as special
cases or approximations from these Bayesian models. The empirical basis and
useful properties of the framework will be discussed and examples of how the
framework can be used to describe different problems given.


title: Convergence of a Family of Series

abstract:
  In this article we construct a family of expressions $\varepsilon(n)$. For
each element E(n) from $\varepsilon(n)$, the convergence of the series $\sum_{n
\ge n_E}{E(n)}$ can be determined in accordance to the theorems of this
article. Some applications are also presented.


title: Extremely chaotic Boolean networks

abstract:
  It is an increasingly important problem to study conditions on the structure
of a network that guarantee a given behavior for its underlying dynamical
system. In this paper we report that a Boolean network may fall within the
chaotic regime, even under the simultaneous assumption of several conditions
which in randomized studies have been separately shown to correlate with
ordered behavior. These properties include using at most two inputs for every
variable, using biased and canalyzing regulatory functions, and restricting the
number of negative feedback loops.
  We also prove for n-dimensional Boolean networks that if in addition the
number of outputs for each variable is bounded and there exist periodic orbits
of length c^n for c sufficiently close to 2, any network with these properties
must have a large proportion of variables that simply copy previous values of
other variables. Such systems share a structural similarity to a relatively
small Turing machine acting on one or several tapes.


title: Notes on Fermi-Dirac Integrals

abstract:
  Fermi-Dirac integrals appear frequently in semiconductor problems, so a basic
understanding of their properties is essential. The purpose of these notes is
to collect in one place, some basic information about Fermi-Dirac integrals and
their properties.
  We also present Matlab scripts that calculate Fermi-Dirac integrals (the
"script F" defined by Dingle (1957)) in three different ways. The codes are
available in Appendix and at the following website: "Notes on Fermi-Dirac
Integrals (4th Edition)" by Raseong Kim, Xufeng Wang, and Mark Lundstrom at
http://nanohub.org/resources/5475
  In the 4th edition, we also provide a new table-based Matlab script (download
available at https://github.com/wang159/FDIntegral_Table) that is less likely
to give large errors in a wide range of input while still much faster than the
rigorous numerical integration.


title:
Axion and Neutralinos from Supersymmetric Extensions of the Standard
  Model with anomalous U(1)'s

abstract:
  We analyze the conditions under which some supersymmetric generalizations of
a class of models descending from string theory allow an axion in the physical
spectrum, due to the presence of anomalous abelian gauge interactions. The
gauge structure of these constructions involve the Stueckelberg supermultiplet
and a supersymmetric version of the Wess-Zumino term for anomaly cancellation.
While these conditions are not satisfied by the MSSM superpotential, we show
that an axion-like particle appears in the spectrum if extra Standard Model
singlets are present. We show that the minimal requirements are met by simple
superpotentials in which the singlet superfield is charged under the anomalous
U(1). The dark matter sector of these models include an axion and several
neutralinos with an axino component.


title:
Stellar Velocities in the Carina, Fornax, Sculptor and Sextans dSph
  Galaxies: Data from the Magellan/MMFS Survey

abstract:
  We present spectroscopic data for individual stars observed from 2004 March
through 2008 August as part of our Michigan/MIKE Fiber System (MMFS) survey of
four dwarf spheroidal (dSph) galaxies: Carina, Fornax, Sculptor and Sextans.
Using MMFS at the Magellan/Clay Telescope at Las Campanas Observatory, we have
acquired 8855 spectra from 7103 red giant candidates in these Galactic
satellites. We list measurements of each star's line-of-sight velocity (median
error +/- 2.1 km/s) and spectral line indices for iron and magnesium absorption
features. We use globular cluster spectra to calibrate the indices onto
standard [Fe/H] metallicity scales, but comparison of the resulting
metallicities with published values suggests that the MMFS indices are best
used as indicators of relative, not absolute metallicity. The empirical
distributions of velocity and spectral indices also allow us to quantify the
amount of contamination by foreground stars. In a companion paper we develop an
algorithm that evaluates the membership probability for each star, showing that
the present MMFS sample contains more than 5000 dSph members, including 774
Carina members, 2483 Fornax members, 1365 Sculptor members, and 441 Sextans
members.


title: Mass Generation from Higgs-like Ghosts

abstract:
  Covariant quantization of gauge theories generally requires the inclusion of
Fadeev Popov ghosts in the gauge-fixed Lagrangian. Normally these ghosts have
fermionic statistics, but in supersymmetric theories that include fermionic
gauge fields, there can also be ghosts with bosonic statistics. Since these
ghosts are scalar bosons, they can have vacuum expectation values (VEVs)
without violating Lorentz invariance. In particular, for the supersymmetric
group SU(2/3), one can choose a gauge with a Higgs-like bosonic ghost potential
that is minimized when one of the ghosts develops a VEV. This VEV breaks the
SU(2) x U(1) subgroup of SU(2/3) down to U(1) and spontaneously generates
vector boson masses, but without the "hierarchy" problems that accompany the
Higgs field. SU(2/3) also has an SU(3) subgroup, and unitarity requires that
the SU(3) gauge bosons must be confined. Since bosonic ghosts do not exist as
particles asymptotically, this kind of theory could be a possible explanation
if no Higgs Boson is detected at the LHC.


title: Forward Physics with Rapidity Gaps at the LHC

abstract:
  A rapidity gap program with great potential can be realized at the Large
Hadron Collider, LHC, by adding a few simple forward shower counters (FSCs)
along the beam line on both sides of the main central detectors, such as CMS.
Measurements of single diffractive cross sections down to the lowest masses can
be made with an efficient level-1 trigger. Exceptionally, the detectors also
make feasible the study of Central Diffractive Excitation, and in particular
the reaction g + g to g + g, in the color singlet channel, effectively using
the LHC as a gluon-gluon collider.


title: Spectral Connectivity Analysis

abstract:
  Spectral kernel methods are techniques for transforming data into a
coordinate system that efficiently reveals the geometric structure - in
particular, the "connectivity" - of the data. These methods depend on certain
tuning parameters. We analyze the dependence of the method on these tuning
parameters. We focus on one particular technique - diffusion maps - but our
analysis can be used for other methods as well. We identify the population
quantities implicitly being estimated, we explain how these methods relate to
classical kernel smoothing and we define an appropriate risk function for
analyzing the estimators. We also show that, in some cases, fast rates of
convergence are possible even in high dimensions.


title:
Enhanced UV Light emission from Silicon nanoparticles induced by Au ion
  implantation

abstract: Study of light emitting silicon fabricated by ion implantation.


title: A computational model of affects

abstract:
  This article provides a simple logical structure, in which affective concepts
(i.e. concepts related to emotions and feelings) can be defined. The set of
affects defined is similar to the set of emotions covered in the OCC model
(Ortony A., Collins A., and Clore G. L.: The Cognitive Structure of Emotions.
Cambridge University Press, 1988), but the model presented in this article is
fully computationally defined.


title:
Bitemporal Dynamics Sinai Divergence, An Energetic Analog to Boltzmann's
  Entropy?

abstract:
  Sinai chaos is characterized by exponential divergence between neighboring
trajectories of a point billiard. If the repulsive potential of the
finite-diameter fixed particle in the middle of the table is made smooth, the
Sinai divergence persists with finite measure. So it does if the smooth
potential is made attractive. So it still does if the potential is in addition
made time-dependent (periodic). Then a systematic decrease in energy of the
moving particle can be predicted to occur in both time directions for a long
time. If so, classical entropy acquires an analog in real space.


title: Doubling property for biLipschitz homogeneous geodesic surfaces

abstract:
  In this paper we discuss general properties of geodesic surfaces that are
locally biLipschitz homogeneous. In particular, we prove that they are locally
doubling and that there exists a special doubling measure analogous to the Haar
measure for locally compact groups.


title: Non-affine geometrization can lead to nonphysical instabilities

abstract:
  Geometrization of dynamics consists of representing trajectories by geodesics
on a configuration space with a suitably defined metric. Previously, efforts
were made to show that the analysis of dynamical stability can also be carried
out within geometrical frameworks, by measuring the broadening rate of a bundle
of geodesics. Two known formalisms are via Jacobi and Eisenhart metrics. We
find that this geometrical analysis measures the actual stability when the
length of any geodesic is proportional to the corresponding time interval. We
prove that the Jacobi metric is not always an appropriate parametrization by
showing that it predicts chaotic behavior for a system of harmonic oscillators.
Furthermore, we show, by explicit calculation, that the correspondence between
dynamical- and geometrical-spread is ill-defined for the Jacobi metric. We find
that the Eisenhart dynamics corresponds to the actual tangent dynamics and is
therefore an appropriate geometrization scheme.


title: Radiative Corrections for SMC Measurements

abstract:
  A numerical study of QED radiative corrections for the SMC experiment at SPS
is been performed. The semi-analytical program POLRAD is been used to get the
size of the radiative corrections for the proton to get the size of the
radiative corrections for the measurements of the proton spin dependent
structure functions $g_1^p(x)$ and $g_2^p(x)$. A brief description of the
program POLRAD is given.


title:
From multiple scattering to van der Waals interactions: exact results
  for eccentric cylinders

abstract:
  In this paper, dedicated to the career of Iver Brevik, we review the
derivation of the retarded van der Waals or Casimir-Polder interaction between
polarizable molecules from the general multiple scattering formulation of
Casimir interactions between bodies. We then apply this van der Waals potential
to examine the interaction between tenuous cylindrical bodies, including
eccentric cylinders, and revisit the vanishing self-energy of a tenuous
dielectric cylinder. In each case, closed-form expressions are obtained.


title: Multi-parameter Quantum Groups and Quantum Shuffles, (I)

abstract:
  In this article, we study the multi-parameter quantum groups defined by
generators and relations associated with symmetrizable generalized Cartan
matrices, together with their representations in the category $\mathcal O$.
This presentation will be convenient for our later discussions. We present two
explicit descriptions here: as a Hopf 2-cocycle deformation, and as the
multi-parameter quantum shuffle realization of the positive part.


title: Formation Mechanism of Atmospheric Pressure Plasma Jet

abstract:
  Atmospheric pressure plasma jet can protrude some 5.0 cm into air. It holds
promise for multivarious innovative applications, but its formation mechanism
remains unsettled. We show that the plasma jet is essentially a streamer corona
totally independent of, but obscured by, dielectric barrier discharge.
Consequently, the jets can be equally successfully generated even with one
single bare metal electrode attached to the tube orifice, both downstream and
upstream simultaneously, and at a significantly reduced voltage. These results
will help understand the underlying physics and facilitate a safer and more
flexible implementation of this marvelous plasma source.


title:
Balancing Exploration and Exploitation by an Elitist Ant System with
  Exponential Pheromone Deposition Rule

abstract:
  The paper presents an exponential pheromone deposition rule to modify the
basic ant system algorithm which employs constant deposition rule. A stability
analysis using differential equation is carried out to find out the values of
parameters that make the ant system dynamics stable for both kinds of
deposition rule. A roadmap of connected cities is chosen as the problem
environment where the shortest route between two given cities is required to be
discovered. Simulations performed with both forms of deposition approach using
Elitist Ant System model reveal that the exponential deposition approach
outperforms the classical one by a large extent. Exhaustive experiments are
also carried out to find out the optimum setting of different controlling
parameters for exponential deposition approach and an empirical relationship
between the major controlling parameters of the algorithm and some features of
problem environment.


title: On time reversal mirrors

abstract:
  The concept of time reversal (TR) of scalar wave is reexamined from basic
principles. Five different time reversal mirrors (TRM) are introduced and their
relations are analyzed. For the boundary behavior, it is shown that for
paraxial wave only the monopole TR scheme satisfies the exact boundary
condition while for spherical wave only one of the mixed mode TR scheme, after
multiplication by two, satisfies the exact boundary condition. The asymptotic
analysis of the near-field focusing property is presented. It is shown that to
have a subwavelength focal spot the TRM should involve dipole fields. The
monopole TR is extremely ineffective to focus below wavelength as the focal
spot size decreases logarithmically with the distance between the source and
TRM. Contrary to the matched field processing and the phase processor, both of
which resemble TR, TR in a weak- or non-scattering medium is usually biased in
the longitudinal direction, especially when TR is carried out on a {\em single}
plane with a {finite} aperture. This is true for all five TR schemes. On the
other hand, the TR focal spot has been shown repeatedly in the literature, both
theoretically and experimentally, to be centered at the source point when the
medium is multiply scattering. A reconciliation of the two seemingly
conflicting results is found in the random fluctuations in the intensity of the
Green function for a multiply scattering medium and the notion of
scattering-enlarged effective aperture.


title:
A Study of the Grunwald-Letnikov Definition for Minimizing the Effects
  of Random Noise on Fractional Order Differential Equations

abstract:
  Of the many definitions for fractional order differintegral, the
Grunwald-Letnikov definition is arguably the most important one. The necessity
of this definition for the description and analysis of fractional order systems
cannot be overstated. Unfortunately, the Fractional Order Differential Equation
(FODE) describing such a systems, in its original form, highly sensitive to the
effects of random noise components inevitable in a natural environment. Thus
direct application of the definition in a real-life problem can yield erroneous
results. In this article, we perform an in-depth mathematical analysis the
Grunwald-Letnikov definition in depth and, as far as we know, we are the first
to do so. Based on our analysis, we present a transformation scheme which will
allow us to accurately analyze generalized fractional order systems in presence
of significant quantities of random errors. Finally, by a simple experiment, we
demonstrate the high degree of robustness to noise offered by the said
transformation and thus validate our scheme.


title: A Novel Parser Design Algorithm Based on Artificial Ants

abstract:
  This article presents a unique design for a parser using the Ant Colony
Optimization algorithm. The paper implements the intuitive thought process of
human mind through the activities of artificial ants. The scheme presented here
uses a bottom-up approach and the parsing program can directly use ambiguous or
redundant grammars. We allocate a node corresponding to each production rule
present in the given grammar. Each node is connected to all other nodes
(representing other production rules), thereby establishing a completely
connected graph susceptible to the movement of artificial ants. Each ant tries
to modify this sentential form by the production rule present in the node and
upgrades its position until the sentential form reduces to the start symbol S.
Successful ants deposit pheromone on the links that they have traversed
through. Eventually, the optimum path is discovered by the links carrying
maximum amount of pheromone concentration. The design is simple, versatile,
robust and effective and obviates the calculation of the above mentioned sets
and precedence relation tables. Further advantages of our scheme lie in i)
ascertaining whether a given string belongs to the language represented by the
grammar, and ii) finding out the shortest possible path from the given string
to the start symbol S in case multiple routes exist.


title:
Complete Identification of a Dynamic Fractional Order System Under
  Non-ideal Conditions Using Fractional Differintegral Definitions

abstract:
  This contribution deals with identification of fractional-order dynamical
systems. System identification, which refers to estimation of process
parameters, is a necessity in control theory. Real processes are usually of
fractional order as opposed to the ideal integral order models. A simple and
elegant scheme of estimating the parameters for such a fractional order process
is proposed. This method employs fractional calculus theory to find equations
relating the parameters that are to be estimated, and then estimates the
process parameters after solving the simultaneous equations. The data used for
the calculations are intentionally corrupted to simulate real-life conditions.
Results show that the proposed scheme offers a very high degree of accuracy
even for erroneous data.


title:
Extension of Max-Min Ant System with Exponential Pheromone Deposition
  Rule

abstract:
  The paper presents an exponential pheromone deposition approach to improve
the performance of classical Ant System algorithm which employs uniform
deposition rule. A simplified analysis using differential equations is carried
out to study the stability of basic ant system dynamics with both exponential
and constant deposition rules. A roadmap of connected cities, where the
shortest path between two specified cities are to be found out, is taken as a
platform to compare Max-Min Ant System model (an improved and popular model of
Ant System algorithm) with exponential and constant deposition rules. Extensive
simulations are performed to find the best parameter settings for non-uniform
deposition approach and experiments with these parameter settings revealed that
the above approach outstripped the traditional one by a large extent in terms
of both solution quality and convergence time.


title:
A Novel Approach for Complete Identification of Dynamic Fractional Order
  Systems Using Stochastic Optimization Algorithms and Fractional Calculus

abstract:
  This contribution deals with identification of fractional-order dynamical
systems. System identification, which refers to estimation of process
parameters, is a necessity in control theory. Real processes are usually of
fractional order as opposed to the ideal integral order models. A simple and
elegant scheme of estimating the parameters for such a fractional order process
is proposed. This method employs fractional calculus theory to find equations
relating the parameters that are to be estimated, and then estimates the
process parameters after solving the simultaneous equations. The said
simultaneous equations are generated and updated using particle swarm
optimization (PSO) technique, the fitness function being the sum of squared
deviations from the actual set of observations. The data used for the
calculations are intentionally corrupted to simulate real-life conditions.
Results show that the proposed scheme offers a very high degree of accuracy
even for erroneous data.


title: Can we Detect Intermediate Mass Ratio Inspirals?

abstract:
  Gravitational waves emitted during intermediate-mass-ratio inspirals (IMRIs)
of intermediate-mass black holes (IMBHs) into supermassive black holes could
represent a very interesting source for LISA. Similarly, IMRIs of stellar-mass
compact objects into IMBHs could be detectable by Advanced LIGO. At present,
however, it is not clear what waveforms could be used for IMRI detection, since
the post-Newtonian approximation breaks down as an IMRI approaches the
innermost stable circular orbit, and perturbative solutions are only known to
the lowest order in the mass ratio. We discuss the expected mismatches between
approximate and true waveforms, and the choice of the best available waveform
as a function of the mass ratio and the total mass of the system. We also
comment on the significance of the spin of the smaller body and the need for
its inclusion in the waveforms.


title: Entropy, Perception, and Relativity

abstract:
  In this paper, I expand Shannon's definition of entropy into a new form of
entropy that allows integration of information from different random events.
Shannon's notion of entropy is a special case of my more general definition of
entropy. I define probability using a so-called performance function, which is
de facto an exponential distribution. Assuming that my general notion of
entropy reflects the true uncertainty about a probabilistic event, I understand
that our perceived uncertainty differs. I claim that our perception is the
result of two opposing forces similar to the two famous antagonists in Chinese
philosophy: Yin and Yang. Based on this idea, I show that our perceived
uncertainty matches the true uncertainty in points determined by the golden
ratio. I demonstrate that the well-known sigmoid function, which we typically
employ in artificial neural networks as a non-linear threshold function,
describes the actual performance. Furthermore, I provide a motivation for the
time dilation in Einstein's Special Relativity, basically claiming that
although time dilation conforms with our perception, it does not correspond to
reality. At the end of the paper, I show how to apply this theoretical
framework to practical applications. I present recognition rates for a pattern
recognition problem, and also propose a network architecture that can take
advantage of general entropy to solve complex decision problems.


title: Envelopes of holomorphy and holomorphic discs

abstract:
  The envelope of holomorphy of an arbitrary domain in a two-dimensional Stein
manifold is identified with a connected component of the set of equivalence
classes of analytic discs immersed into the Stein manifold with boundary in the
domain. This implies, in particular, that for each of its points the envelope
of holomorphy contains an embedded (non-singular) Riemann surface (and also an
immersed analytic disc) passing through this point with boundary contained in
the natural embedding of the original domain into its envelope of holomorphy.
Moreover, it says, that analytic continuation to a neighbourhood of an
arbitrary point of the envelope of holomorphy can be performed by applying the
continuity principle once. Another corollary concerns representation of certain
elements of the fundamental group of the domain by boundaries of analytic
discs. A particular case is the following. Given a contact three-manifold with
Stein filling, any element of the fundamental group of the contact manifold
whose representatives are contractible in the filling can be represented by the
boundary of an immersed analytic disc.


title:
Formulae of Partial Reduction for Linear Systems of First Order Operator
  Equations

abstract:
  This paper deals with reduction of non-homogeneous linear systems of first
order operator equations with constant coefficients. An equivalent reduced
system, consisting of higher order linear operator equations having only one
variable and first order linear operator equations in two variables, is
obtained by using the rational canonical form.


title: Stretch-Twist torus dynamo in compact Riemannian manifolds

abstract:
  Earlier Arnold, Zeldovich, Ruzmaikin and Sokoloff [\textbf{JETP (1982)}] have
computed the eigenvalue of a uniform stretching torus transformation which
result on the first Riemann metric solution of the dynamo action problem.
Recently some other attempts to obtain Riemann metrics representing dynamo
action through conformal maps have been undertaken [{\textbf{Phys. Plasmas 14
(2007)}]. Earlier, Gilbert [\textbf{Proc. Roy. Soc. London A(2003)}] has
investigated a more realistic dynamo map solution than the one presented by
Arnold et al by producing a shearing of the Arnold's cat map, by eigenvalue
problem of a dynamo operator. In this paper, the eigenvalue of the Riemann
twisted torus dynamo flow metric is obtained as the ratio between the poloidal
and toroidal components of the flow. This result is obtained from the Euler
equation. In the twisted torus, the eigenvalue of the Riemann metric is
${m}_{\pm}=\frac{1\pm{\sqrt{5}}}{2}$, which is quite close to the value
obtained by Arnold. In the case the viscosity Reynolds number $Re\to{\infty}$,
the torus flow is unstable as one approaches the torus axis. In Arnold's dynamo
metric the eigenvalues are ${\chi}_{\pm}=\frac{3\pm{\sqrt{5}}}{2}$ which are
very close to the above value. Eigenvalues determine the growth rates of the
velocity ratio between poloidal and toroidal components of the flow. The curved
flow in torus follow previous work by Chen et al [\textbf{Phys Fluids (2006)}].
The ${\alpha}$-effect dynamo is shown to be a second-order effect in the torus
curvature and velocity flow. Loop dynamo flows and maps are also discussed.


title:
Designing microstructured polymer optical fibers for cascaded quadratic
  soliton compression of femtosecond pulses

abstract:
  The dispersion of index-guiding microstructured polymer optical fibers is
calculated for second-harmonic generation. The quadratic nonlinearity is
assumed to come from poling of the polymer, which in this study is chosen to be
the cyclic olefin copolymer Topas. We found a very large phase mismatch between
the pump and the second-harmonic waves. Therefore the potential for cascaded
quadratic second-harmonic generation is investigated in particular for soliton
compression of fs pulses. We found that excitation of temporal solitons from
cascaded quadratic nonlinearities requires an effective quadratic nonlinearity
of 5 pm/V or more. This might be reduced if a polymer with a low Kerr nonlinear
refractive index is used. We also found that the group-velocity mismatch could
be minimized if the design parameters of the microstructured fiber are chosen
so the relative hole size is large and the hole pitch is on the order of the
pump wavelength. Almost all design-parameter combinations resulted in cascaded
effects in the stationary regime, where efficient and clean soliton compression
can be found. We therefore did not see any benefit from choosing a fiber design
where the group-velocity mismatch was minimized. Instead numerical simulations
showed excellent compression of $\lambda=800$ nm 120 fs pulses with nJ pulse
energy to few-cycle duration using a standard endlessly single-mode design with
a relative hole size of 0.4.


title:
Differential transcendency in the theory of linear differential systems
  with constant coefficients

abstract:
  In this paper we consider a reduction of a non-homogeneous linear system of
first order operator equations to a totally reduced system. Obtained results
are applied to Cauchy problem for linear differential systems with constant
coefficients and to the question of differential transcendency.


title: Giant magnons and spiky strings on the conifold

abstract:
  We find explicit solutions for giant magnons and spiky strings on the
squashed three dimensional sphere. For a special value of the squashing
parameter the solutions describe strings moving in a sector of the conifold,
while for another value of the squashing parameter we recover the known results
on the round three dimensional sphere. A new feature is that the energy and the
momenta enter in the dispersion relation of the conifold in a transcendental
way.


title: Effect of Tuned Parameters on a LSA MCQ Answering Model

abstract:
  This paper presents the current state of a work in progress, whose objective
is to better understand the effects of factors that significantly influence the
performance of Latent Semantic Analysis (LSA). A difficult task, which consists
in answering (French) biology Multiple Choice Questions, is used to test the
semantic properties of the truncated singular space and to study the relative
influence of main parameters. A dedicated software has been designed to fine
tune the LSA semantic space for the Multiple Choice Questions task. With
optimal parameters, the performances of our simple model are quite surprisingly
equal or superior to those of 7th and 8th grades students. This indicates that
semantic spaces were quite good despite their low dimensions and the small
sizes of training data sets. Besides, we present an original entropy global
weighting of answers' terms of each question of the Multiple Choice Questions
which was necessary to achieve the model's success.


title:
Coherent State Preparation and Observation of Rabi Oscillations in a
  Single Molecule

abstract:
  We report on the excitation of single molecules via narrow zero-phonon
transitions using short laser pulses. By monitoring the Stokes-shifted
fluorescence, we studied the excited state population as a function of the
delay time, laser intensity, and frequency detuning. A pi-pulse excitation was
demonstrated with merely 500 photons, and 5 Rabi cycles were achieved at higher
excitation powers. Our findings are in good agreement with theoretical
calculations and provide a first step toward coherent manipulation of the
electronic states of single molecules with few photons.


title: Plans D'Experiences D'Information De Kullback-Leibler Minimale

abstract:
  Experimental designs are tools which can dramatically reduce the number of
simulations required by time-consuming computer codes. Because we don't know
the true relation between the response and inputs, designs should allow one to
fit a variety of models and should provide information about all portions of
the experimental region. One strategy for selecting the values of the inputs at
which to observe the response is to choose these values so they are spread
evenly throughout the experimental region, according to "space-filling
designs". In this article, we suggest a new method based on comparing the
empirical distribution of the points in a design to the uniform distribution
with the Kullback-Leibler information. The considered approach consists in
estimating this difference or, reciprocally, the Shannon entropy. The entropy
is estimated by a Monte Carlo method where the density function is replaced by
its kernel density estimator or by using the nearest neighbor distances


title:
Recovery of Missing Samples in Oversampling Formulas for Band Limited
  Functions

abstract:
  In a previous paper, the author constructed frames and oversampling formulas
for band-limited functions, in the framework of the theory of shift-invariant
spaces. In this article we study the problem of recovering missing samples.
  We find a sufficient condition for the recovery of a finite set of missing
samples. The condition is expressed as a linear independence of the components
of a vector W over the space of trigonometric polynomials determined by the
frequencies of the missing samples. We apply the theory to the derivative
sampling of any order and we illustrate our results with a numerical
experiment.


title: Cosmology in non-minimal Yang-Mills/Maxwell theory

abstract:
  We review cosmology in non-minimal Yang-Mills/Maxwell theory, in which the
Yang-Mills/electromagnetic field couples to a function of the scalar curvature.
We show that power-law inflation can be realized due to the non-minimal
gravitational coupling of the Yang-Mills field which may be caused by quantum
corrections. Moreover, we study non-minimal vector model in the framework of
modified gravity and demonstrate that both inflation and the late-time
accelerated expansion of the universe can be realized. We also discuss the
cosmological reconstruction of the Yang-Mills theory. Furthermore, we
investigate late-time cosmology in non-minimal Maxwell-Einstein theory. We
explore the forms of the non-minimal gravitational coupling which generate the
finite-time future singularities and the general conditions for this coupling
in order that the finite-time future singularities cannot appear.


title:
DAMA/LIBRA findings urge replacement of the WIMP hypotheses by the
  daemon paradigm as a basis for experimental studies of DM objects

abstract:
  The simplest version of the daemon paradigm suggests the modulated 2-6-keV
range events in DAMA/NaI and DAMA/LIBRA detectors are caused by the iodine ions
knocked out elastically by the electrically neutral c-daemons moving with V =
30-50 km/s (c-daemon is a complex of negative daemon located in a remainder of
formerly captured nucleus where the daemon decomposes nucleons one by one with
~10^-6 s mean interval). Furthermore, after the 2-6 keV event occurred, in
subsequent ~10^-6 s, the c-daemon (which becomes negative during this time)
recaptures new nucleus with resulting scintillations in ~10 MeV range! The last
possibility was so far overlooked in the experiments as it did not stem from
WIMP hypotheses. A modification of the NaI(Tl) experiments is suggested for
revealing the effect described. Independently of the outcome, any obtained
result will be important for refining the daemon paradigm further on.


title: Theoretical Analysis of Compressive Sensing via Random Filter

abstract:
  In this paper, the theoretical analysis of compressive sensing via random
filter, firstly outlined by J. Romberg [compressive sensing by random
convolution, submitted to SIAM Journal on Imaging Science on July 9, 2008], has
been refined or generalized to the design of general random filter used for
compressive sensing. This universal CS measurement consists of two parts: one
is from the convolution of unknown signal with a random waveform followed by
random time-domain subsampling; the other is from the directly time-domain
subsampling of the unknown signal. It has been shown that the proposed approach
is a universally efficient data acquisition strategy, which means that the
n-dimensional signal which is S sparse in any sparse representation can be
exactly recovered from Slogn measurements with overwhelming probability.


title: Pattern speed evolution and bar reformation

abstract:
  Bars in spiral galaxies can weaken through gas inflow towards the center, and
angular momentum transfer. Several bar episodes can follow one another in the
life of the galaxy, if sufficient gas is accreted from the intergalactic medium
to revive young disks.
  Pattern speeds of the successive bars are different, due to mass
concentration, or increased velocity dispersion of the remaining stellar
component. In the same time, the spiral galaxy evolves in morphological type.
Numerical simulations are presented, trying to correlate type and bar pattern
speeds.


title:
Additional non-Coulomb electron-electon interaction in multielectron
  systems

abstract:
  The author suggests an approach based on the separation of total energy of
multielectron systems into the semi-classical Coulomb part and the
non-classical additional part. This approach allows on the one hand to simplify
calculations and on the other hand to see very simple and very interesting
relations. These relations were not obvious when using more complex methods.
The most interesting aspect is that on all levels of chemical matter - from
two-electron atoms up to molecules and crystals - we find additional
non-classical electron-electron attraction. The most important practical
consequence is the discovery that under certain conditions additional
electron-electron attraction can exceed usual electron-electron repulsion. It
can result in existence of ordered structures of a new type in a special-way
exited matter


title: Calabi flow and projective embeddings

abstract:
  Let X be a smooth subvariety of CP^N. We study a flow, called balancing flow,
on the space of projectively equivalent embeddings of X, which attempts to
deform the given embedding into a balanced one. If L->X is an ample line
bundle, considering embeddings via H^0(L^k) gives a sequence of balancing
flows. We prove that, provided these flows are started at appropriate points,
they converge to Calabi flow for as long as it exists. This result is the
parabolic analogue of Donaldson's theorem relating balanced embeddings to
metrics with constant scalar curvature [JDG 59(3):479-522, 2001]. In our proof
we combine Donaldson's techniques with an asymptotic result of Liu-Ma
[arXiv:math/0601260v2] which, as we explain, describes the asymptotic behaviour
of the derivative of the map FS\circ Hilb whose fixed points are balanced
metrics.


title:
Symmetry, winding number and topological charge of vortex solitons in
  discrete-symmetry media

abstract:
  We determine the functional behavior near the discrete rotational symmetry
axis of discrete vortices of the nonlinear Schr\"odinger equation. We show that
these solutions present a central phase singularity whose charge is restricted
by symmetry arguments. Consequently, we demonstrate that the existence of
high-charged discrete vortices is related to the presence of other off-axis
phase singularities, whose positions and charges are also restricted by
symmetry arguments. To illustrate our theoretical results, we offer two
numerical examples of high-charged discrete vortices in photonic crystal fibers
showing hexagonal discrete rotational invariance.


title: Ab-initio simulation and experimental validation of beta-titanium alloys

abstract:
  In this progress report we present a new approach to the ab-initio guided
bottom up design of beta-Ti alloys for biomedical applications using a quantum
mechanical simulation method in conjunction with experiments. Parameter-free
density functional theory calculations are used to provide theoretical guidance
in selecting and optimizing Ti-based alloys with respect to three constraints:
(i) the use of non-toxic alloy elements; (ii) the stabilization of the body
centered cubic beta phase at room temperature; (iii) the reduction of the
elastic stiffness compared to existing Ti-based alloys. Following the
theoretical predictions, the alloys of interest are cast and characterized with
respect to their crystallographic structure, microstructure, texture, and
elastic stiffness. Due to the complexity of the ab initio calculations, the
simulations have been focused on a set of binary systems of Ti with two
different high melting bcc metals, namely, Nb and Mo. Various levels of model
approximations to describe mechanical and thermodynamic properties are tested
and critically evaluated. The experiments are conducted both, on some of the
binary alloys and on two more complex engineering alloy variants, namely,
Ti-35wt.%Nb-7wt.%Zr-5wt.%Ta and a Ti-20wt.%Mo-7wt.%Zr-5wt.%Ta.


title: Transient jets in the symbiotic prototype Z Andromedae

abstract:
  We present development of the collimated bipolar jets from the symbiotic
prototype Z And that appeared and disappeared during its 2006 outburst. In 2006
July Z And reached its historical maximum at U ~ 8.0. During this period, rapid
photometric variations with Dm ~ 0.06 mag on the timescale of hours developed.
Simultaneously, high-velocity satellite components appeared on both sides of
the H-alpha and H-beta emission line profiles. They were launched
asymmetrically with the red/blue velocity ratio of 1.2 - 1.3. From about
mid-August they became symmetric. Their spectral properties indicated ejection
of bipolar jets collimated within an average opening angle of 6.1 degrees. We
estimated average outflow rate via jets to dM(jet)/dt ~
2xE10-6(R(jet)/1AU)**(1/2) M(Sun)/year, during their August - September
maximum, which corresponds to the emitting mass in jets, M(jet, emitting) ~
6xE-10(Rjet)/1AU)^{3/2} M(Sun). During their lifetime, the jets released the
total mass of M(jet, total) approx 7.4x1E-7 M(Sun). Evolution in the rapid
photometric variability and asymmetric ejection of jets around the optical
maximum can be explained by a disruption of the inner parts of the disk caused
by radiation-induced warping of the disk.


title: Efimov physics in a finite volume

abstract:
  Three bosons with large scattering length show universal properties that do
not depend on the details of the interaction at short distances. In the
three-boson system, these properties include a geometric spectrum of shallow
three-body states called "Efimov states" and log-periodic dependence of
scattering observables on the scattering length. We investigate the
modification of the Efimov states in a finite cubic box and calculate the
dependence of their energies on the box size using effective field theory. We
explicitly verify the renormalization of the effective field theory in the
finite volume.


title:
Oxygen isotope effect on structural parameters and on the thermal motion
  in La$_2$CuO$_4$

abstract:
  We studied the oxygen isotope effect (OIE) on the zero point motion and the
thermal motion as well as on structural parameters in La$_2$CuO$_4$ by means of
high-resolution neutron diffraction experiments. We found a negative OIE on the
lattice parameters (-0.01%). The OIE on the isotropic thermal parameters turned
out to be positive for lanthanum, copper and negative for the oxygen atoms,
respectively. The Rietvield refinement of the anisotropic thermal parameters of
the different directions yielded the same sign of the OIE for each ion. Our
analysis shows that the OIE on isotropic thermal parameters is most pronounced
for La at 15 K (up to 100%) which we found to be originating mainly from the
thermal motion in x-direction as determined from the refinement of the
anisotropic thermal parameters.


title:
Phase-sensitive Manipulations of Squeezed Vacuum Field in an Optical
  Parametric Amplifier inside an Optical Cavity

abstract:
  Squeezed vacuum field can be amplified or deamplified when it is injected, as
the signal beam, into a phase-sensitive optical parametric amplifier (OPA)
inside an optical cavity. The spectral features of the reflected quantized
signal field are controlled by the relative phase between the injected squeezed
vacuum field and the pump field for the OPA. The experimental results
demonstrate coherent phenomena of OPA in the quantum regime, and show
phase-sensitive manipulations of quantum fluctuations for quantum information
processing.


title: Deposition of Diamond-like Carbon films using Dense Plasma Focus

abstract:
  Diamond Like Carbon (DLC) films were deposited on quartz substrates using
Dense Plasma Focus (DPF) method. The formation of ${\rm sp^3}$ bonds as is it's
content in the film strongly depends on the substrate and it seems quartz is
not a suitable substrate. However, we report here the formation of DLC films on
quartz substrates that were maintained at elevated temperatures and show the
content of carbon atoms with ${\rm sp^3}$ bonds in the film is directly
proportional to the substrate's temperature. Not only does this give good
control of film fabrication, but also shows how to take advantage of DLC film's
anti-wear, scratch resistant properties on material surfaces that require
protection.


title:
Stellar, Brown Dwarf, and Multiple Star Properties from Hydrodynamical
  Simulations of Star Cluster Formation

abstract:
  We report the statistical properties of stars, brown dwarfs and multiple
systems obtained from the largest hydrodynamical simulation of star cluster
formation to date that resolves masses down to the opacity limit for
fragmentation (a few Jupiter masses). The simulation is essentially identical
to that of Bate, Bonnell & Bromm except that the initial molecular cloud is
larger and more massive. It produces more than 1250 stars and brown dwarfs,
providing unprecedented statistical information that can be compared with
observational surveys.
  We find that hydrodynamical/sink particle simulations can reproduce many of
the observed stellar properties very well. Binarity as a function of primary
mass, the frequency of very-low-mass (VLM) binaries, general trends for the
separation and mass ratio distributions of binaries, and the relative orbital
orientations of triples systems are all in reasonable agreement with
observations. We also examine the radial variations of binarity, velocity
dispersion, and mass function in the resulting stellar cluster and the
distributions of disc truncation radii due to dynamical interactions. For VLM
binaries, we find that their frequency when using small accretion radii and
gravitational softening is similar to that expected from observational surveys
(approximately 20 percent). We also find that VLM binaries evolve from wide,
unequal-mass systems towards close equal-mass systems as they form. The two
main deficiencies of the calculations are that they over produce brown dwarfs
relative to stars and that there are too few unequal mass binaries with K and
G-dwarf primaries. [Abridged]


title: A strict non-standard inequality .999... < 1

abstract:
  Is .999... equal to 1? Lightstone's decimal expansions yield an infinity of
numbers in [0,1] whose expansion starts with an unbounded number of digits "9".
We present some non-standard thoughts on the ambiguity of an ellipsis, modeling
the cognitive concept of generic limit of B. Cornu and D. Tall. A choice of a
non-standard hyperinteger H specifies an H-infinite extended decimal string of
9s, corresponding to an infinitesimally diminished hyperreal value. In our
model, the student resistance to the unital evaluation of .999... is directed
against an unspoken and unacknowledged application of the standard part
function, namely the stripping away of a ghost of an infinitesimal, to echo
George Berkeley. So long as the number system has not been specified, the
students' hunch that .999... can fall infinitesimally short of 1, can be
justified in a mathematically rigorous fashion.


title: Transference principles and locally symmetric spaces

abstract:
  We explain how the Transference Principles from Diophantine approximation can
be interpreted in terms of geometry of the locally symmetric spaces $T_n=SO(n)
\backslash SL(n,R) /SL(n,Z)$ with $n>1$, and how, via this dictionary, they
become transparent geometric remarks and can be easily proved. Indeed, a finite
family of linear forms is naturally identified to a locally geodesic ray in a
space $T_n$ and the way this family is approximated is reflected by the heights
at which the ray rises in the cuspidal end. The only difference between the two
types of approximation appearing in a Transference Theorem is that the height
is measured with respect to different rays in $W$, a Weyl chamber in $T_n$.
Thus the Transference Theorem is equivalent to a relation between the Busemann
functions of two rays in $W$. This relation is easy to establish on $W$,
because restricted to it the two Busemann functions become two linear forms.
Since $T_n$ is at finite Hausdorff distance from $W$, the same relation is
satisfied up to a bounded perturbation on the whole of $T_n$.


title: Automatic Modular Abstractions for Linear Constraints

abstract:
  We propose a method for automatically generating abstract transformers for
static analysis by abstract interpretation. The method focuses on linear
constraints on programs operating on rational, real or floating-point variables
and containing linear assignments and tests. In addition to loop-free code, the
same method also applies for obtaining least fixed points as functions of the
precondition, which permits the analysis of loops and recursive functions. Our
algorithms are based on new quantifier elimination and symbolic manipulation
techniques. Given the specification of an abstract domain, and a program block,
our method automatically outputs an implementation of the corresponding
abstract transformer. It is thus a form of program transformation. The
motivation of our work is data-flow synchronous programming languages, used for
building control-command embedded systems, but it also applies to imperative
and functional programming.


title: The LSST Data Mining Research Agenda

abstract:
  We describe features of the LSST science database that are amenable to
scientific data mining, object classification, outlier identification, anomaly
detection, image quality assurance, and survey science validation. The data
mining research agenda includes: scalability (at petabytes scales) of existing
machine learning and data mining algorithms; development of grid-enabled
parallel data mining algorithms; designing a robust system for brokering
classifications from the LSST event pipeline (which may produce 10,000 or more
event alerts per night); multi-resolution methods for exploration of petascale
databases; indexing of multi-attribute multi-dimensional astronomical databases
(beyond spatial indexing) for rapid querying of petabyte databases; and more.


title: New asymptotic estimates for spherical designs

abstract:
  Let N(n, t) be the minimal number of points in a spherical t-design on the
unit sphere S^n in R^{n+1}. For each n >= 3, we prove a new asymptotic upper
bound N(n, t) <= C(n)t^{a_n}, where C(n) is a constant depending only on n, a_3
<= 4, a_4 <= 7, a_5 <= 9, a_6 <= 11, a_7 <= 12, a_8 <= 16, a_9 <= 19, a_10 <=
22, and a_n < n/2*log_2(2n), n > 10.


title:
The peculiar molecular envelope around the post-AGB star IRAS
  08544--4431

abstract:
  Circumbinary disks have been hypothesized to exist around a number of binary
post-AGB stars. Although most of the circumbinary disks have been inferred
through the near IR excess, a few of them are strong emitters of molecular
emission. Here we present high angular resolution observations of the emission
of $^{12}$CO and its isotopomer $^{13}$CO J=2--1 line from the circumstellar
envelope around the binary post-AGB star IRAS 08544$-$4431, which is one of the
most prominent members of this class of objects. We find that the envelope is
resolved in our observations and two separate components can be identified: (a)
a central extended and strong component with very narrow linewidth between 2 -
6 \kms; (b) a weak bipolar outflow with expansion velocity up to 8 \kms. The
central compact component possesses low and variable $^{12}$CO/$^{13}$CO J=2--1
line ratio, indicating optically thick emission of the main isotope. We
estimate a molecular gas mass of 0.0047 M$_\odot$ for this component based on
the optically thinner $^{13}$CO J=2--1 line. We discuss the relation of the
molecular envelope and the circumbinary disk inferred from near IR excess and
compare with other known cases where the distribution of molecular gas has been
imaged at high angular resolution.


title:
VLT/FORS1 spectrophotometry of the first planetary nebula discovered in
  the Phoenix dwarf galaxy

abstract:
  Context: A planetary nebula (PN) candidate was discovered during FORS imaging
of the Local Group dwarf galaxy Phoenix. Aims: Use this PN to complement
abundances from red-giant stars. Methods: FORS spectroscopy was used to confirm
the PN classification. Empirical methods and photoionization modeling were used
to derive elemental abundances from the emission line fluxes and to
characterize the central star. Results: For the elements deemed most reliable
for measuring the metallicity of the interstellar medium (ISM) from which the
PN formed, [O/H] ~ -0.46 and [Ar/H] ~ -1.03. [O/H] has lower measurement errors
but greater uncertainties due to the unresolved issue of oxygen enrichment in
the PN precursor star. Conclusions: Earlier than 2 Gyr ago (the lower limit of
the derived age for the central star) the ISM had Z = 0.002--0.008, a range
slightly more metal-rich than the one provided by stars. Comparing our
PN-to-stellar values to surveys for other dwarf Local Group galaxies, Phoenix
appears as an outlier.


title:
New Constraints on the Asteroid 298 Baptistina, the Alleged Family
  Member of the K/T Impactor

abstract:
  In their study Bottke et al. (2007) suggest that a member of the Baptistina
asteroid family was the probable source of the K/T impactor which ended the
reign of the Dinosaurs 65 Myr ago. Knowledge of the physical and material
properties pertaining to the Baptistina asteroid family are, however, not well
constrained. In an effort to begin addressing the situation, data from an
international collaboration of observatories were synthesized to determine the
rotational period of the family's largest member, asteroid 298 Baptistina (P_r
= 16.23+-0.02 hrs). Discussed here are aspects of the terrestrial impact
delivery system, implications arising from the new constraints, and prospects
for future work.


title: Hidden vector dark matter

abstract:
  We show that dark matter could be made of massive gauge bosons whose
stability doesn't require to impose by hand any discrete or global symmetry.
Stability of gauge bosons can be guaranteed by the custodial symmetry
associated to the gauge symmetry and particle content of the model. The
particle content we consider to this end is based on a hidden sector made of a
vector multiplet associated to a non-abelian gauge group and of a scalar
multiplet charged under this gauge group. The hidden sector interacts with the
Standard Model particles through the Higgs portal quartic scalar interaction in
such a way that the gauge bosons behave as thermal WIMPS. This can lead easily
to the observed dark matter relic density in agreement with the other various
constraints, and can be tested experimentally in a large fraction of the
parameter space. In this model the dark matter direct detection rate and the
annihilation cross section can decouple if the Higgs portal interaction is
weak.


title:
Micromagnetic simulations of persistent oscillatory modes excited by
  spin-polarized current in nanoscale exchange-biased spin valves

abstract:
  We perform 3D micromagnetic simulations of current-driven magnetization
dynamics in nanoscale exchange biased spin-valves that take account of (i) back
action of spin-transfer torque on the pinned layer, (ii) non-linear damping and
(iii) random thermal torques. Our simulations demonstrate that all these
factors significantly impact the current-driven dynamics and lead to a better
agreement between theoretical predictions and experimental results. In
particular, we observe that, at a non-zero temperature and a sub-critical
current, the magnetization dynamics exhibits nonstationary behaviour in which
two independent persistent oscillatory modes are excited which compete for the
angular momentum supplied by spin-polarized current. Our results show that this
multi-mode behaviour can be induced by combined action of thermal and spin
transfer torques.


title:
A Bit of Information Theory, and the Data Augmentation Algorithm
  Converges

abstract:
  The data augmentation (DA) algorithm is a simple and powerful tool in
statistical computing. In this note basic information theory is used to prove a
nontrivial convergence theorem for the DA algorithm.


title: Full Numerical Simulations of Catastrophic Small Body Collisions

abstract:
  The outcome of collisions between small icy bodies, such as Kuiper belt
objects, is poorly understood and yet a critical component of the evolution of
the trans-Neptunian region. The expected physical properties of outer solar
system materials (high porosity, mixed ice-rock composition, and low material
strength) pose significant computational challenges. We present results from
catastrophic small body collisions using a new hybrid hydrocode to $N$-body
code computational technique. This method allows detailed modeling of shock
propagation and material modification as well as gravitational reaccumulation.
Here, we consider a wide range of material strengths to span the possible range
of Kuiper belt objects. We find that the shear strength of the target is
important in determining the collision outcome for 2 to 50-km radius bodies,
which are traditionally thought to be in a pure gravity regime. The
catastrophic disruption and dispersal criteria, $Q_D^*$, can vary by up to a
factor of three between strong crystalline and weak aggregate materials. The
material within the largest reaccumulated remnants experiences a wide range of
shock pressures. The dispersal and reaccumulation process results in the
material on the surfaces of the largest remnants having experienced a wider
range of shock pressures compared to material in the interior. Hence, depending
on the initial structure and composition, the surface materials on large,
reaccumulated bodies in the outer solar system may exhibit complex spectral and
albedo variations. Finally, we present revised catastrophic disruption criteria
for a range of impact velocities and material strengths for outer solar system
bodies.


title: PAMELA data and leptonically decaying dark matter

abstract:
  Recently PAMELA released their first results on the positron and antiproton
ratios. Stimulated by the new data, we studied the cosmic ray propagation
models and calculated the secondary positron and antiproton spectra. The low
energy positron ratio can be consistent with data in the convection propagation
model. Above $\sim 10$ GeV PAMELA data shows a clear excess on the positron
ratio. However, the secondary antiproton is roughly consistent with data. The
positron excess may be a direct evidence of dark matter annihilation or decay.
We compare the positron and anti-proton spectra with data by assuming dark
matter annihilates or decays into different final states. The PAMELA data
actually excludes quark pairs being the main final states, disfavors gauge
boson final states. Only in the case of leptonic final states the positron and
anti-proton spectra can be explained simultaneously. We also compare the
decaying and annihilating dark matter scenarios to account for the PAMELA
results and prefer to the decaying dark matter. Finally we consider a decaying
neutralino dark matter model in the frame of supersymmetry with R-parity
violation. The PAMELA data is well fitted with neutralino mass $600\sim 2000$
GeV and life time $\sim 10^{26}$ seconds. We also demonstrate that neutralino
with mass around 2TeV can fit PAMELA and ATIC data simultaneously.


title:
Static and Dynamic irreversible magnetic properties of high temperature
  superconductors

abstract:
  This thesis describes experimental and theoretical study of static and
dynamic aspects of the irreversible magnetic behavior of high-Tc
superconductors. Experimentally, conventional magnetometry and novel Hall-probe
array techniques are employed. Using both techniques extends significantly the
experimental possibilities and yields a wealth of new experimental results.


title: On sutured Floer homology and the equivalence of Seifert surfaces

abstract:
  We study the sutured Floer homology invariants of the sutured manifold
obtained by cutting a knot complement along a Seifert surface, R. We show that
these invariants are finer than the "top term" of the knot Floer homology,
which they contain. In particular, we use sutured Floer homology to distinguish
two non-isotopic minimal genus Seifert surfaces for the knot 8_3. A key
ingredient for this technique is finding appropriate Heegaard diagrams for the
sutured manifold associated to the complement of a Seifert surface.


title: Discussing string extensions of the Standard Model in D brane world

abstract:
  In this talk we will describe the problems that one encounters when one tries
to connect string theory with particle phenomenology. Then, in order to have
chiral matter describing quarks and leptons, we introduce the magnetized D
branes. Finally, as an explicit example of a string extension of the Standard
Model, we will describe the one constructed by Ibanez, Marchesano and Rabadan.


title:
Length-dependent Raman spectroscopy of single-walled carbon nanotubes:
  the effect of dispersant on defects

abstract:
  We compare Raman spectra from aqueous suspensions of length-separated
single-walled carbon nanotubes (SWCNTs) dispersed using either polymer
adsorption of single-stranded DNA or miscelle encapsulation with sodium
deoxycholate surfactant. The Raman spectral features, other than the D-band,
increase monotonically with nanotube length in both dispersion schemes. The
intensity ratio of the disorder-induced D to G' Raman bands decays as a
function of SWCNT length, proportional to 1/L, as expected for endcap defects.
While the UV-vis absorption and fluorescence also increase with length for both
dispersants, the fluorescence intensity is dramatically lower for DNA-wrapped
SWCNTs of equal length. The similarities in the length-dependent D/G' ratios
exclude defects as an explanation for the fluorescence decrease in DNA versus
deoxycholate dispersions.


title: Constraining effective quantum gravity with LISA

abstract:
  All modern routes leading to a quantum theory of gravity -- i.e.,
perturbative quantum gravitational one-loop exact correction to the global
chiral current in the standard model, string theory, and perhaps even loop
quantum gravity -- require supplementing the Einstein-Hilbert action with a
parity-violating Chern-Simons term. Such a term leads to amplitude-birefringent
gravitational wave propagation: i.e., one (circular) polarization state
amplified with propagation while the other is attenuated. The proposed Laser
Interferometer Space Antenna (LISA) is capable of observing gravitational wave
sources at cosmological distances, suggesting the possibility that LISA
observations may place a strong bound on this manifestation of quantum gravity.
Here we report on a calculation of the effect that spacetime amplitude
birefringence has on the signal LISA is capable of observing from inspiraling
supermassive black hole binaries at large redshift. We find that the
birefringence manifests itself in the observations as an anomalous precession
of the binary's orbital angular momentum as it evolves toward coalescence,
whose magnitude depends on the integrated history of the Chern-Simons coupling
over the worldline of radiation wavefront. We estimate that LISA could place
bounds on Chern-Simons modified gravity that are several orders of magnitude
stronger than the present Solar System constraints, thus providing a probe of
the quantum structure of spacetime.


title:
A model of returns for the post-credit-crunch reality: Hybrid Brownian
  motion with price feedback

abstract:
  The market events of 2007-2009 have reinvigorated the search for realistic
return models that capture greater likelihoods of extreme movements. In this
paper we model the medium-term log-return dynamics in a market with both
fundamental and technical traders. This is based on a Poisson trade arrival
model with variable size orders. With simplifications we are led to a hybrid
SDE mixing both arithmetic and geometric Brownian motions, whose solution is
given by a class of integrals of exponentials of one Brownian motion against
another, in forms considered by Yor and collaborators. The reduction of the
hybrid SDE to a single Brownian motion leads to an SDE of the form considered
by Nagahara, which is a type of "Pearson diffusion", or equivalently a
hyperbolic OU SDE. Various dynamics and equilibria are possible depending on
the balance of trades. Under mean-reverting circumstances we arrive naturally
at an equilibrium fat-tailed return distribution with a Student or Pearson Type
IV form. Under less restrictive assumptions richer dynamics are possible,
including bimodal structures. The phenomenon of variance explosion is
identified that gives rise to much larger price movements that might have a
priori been expected, so that "$25\sigma$" events are significantly more
probable. We exhibit simple example solutions of the Fokker-Planck equation
that shows how such variance explosion can hide beneath a standard Gaussian
facade. These are elementary members of an extended class of distributions with
a rich and varied structure, capable of describing a wide range of market
behaviours. Several approaches to the density function are possible, and an
example of the computation of a hyperbolic VaR is given. The model also
suggests generalizations of the Bougerol identity.


title: On the $8n^2$-inequality

abstract:
  We give a complete proof of the so called $8n^2$-inequality, a local
inequality for the self-intersection of a movable linear system at an isolated
centre of a non canonical singularity. The inequality was suggested and several
times published by I.Cheltsov but some of his arguments are faulty. We explain
the mistake and replace the faulty piece by a correct argument.


title: Baryonic Response of Dense Holographic QCD

abstract:
  The response function of a homogeneous and dense hadronic system to a
time-dependent (baryon) vector potential is discussed for holographic dense QCD
(D4/D8 embedding) both in the confined and deconfined phases. Confined
holographic QCD is an uncompressible and static baryonic insulator at large N_c
and large \lambda, with a gapped vector spectrum and a massless pion.
Deconfined holographic QCD is a diffusive conductor with restored chiral
symmetry and a gapped transverse baryonic current. Similarly, dense D3/D7 is
diffusive for any non-zero temperature at large N_c and large \lambda. At zero
temperature dense D3/D7 exhibits a baryonic longitudinal visco-elastic mode
with a first sound speed \lambda/\sqrt{3} and a small width due to a shear
viscosity to baryon ratio \eta/n_B=\hbar/4. This mode is turned diffusive by
arbitrarily small temperatures, a hallmark of holography.


title: Dynamics of curved interfaces

abstract:
  Stochastic growth phenomena on curved interfaces are studied by means of
stochastic partial differential equations. These are derived as counterparts of
linear planar equations on a curved geometry after a reparametrization
invariance principle has been applied. We examine differences and similarities
with the classical planar equations. Some characteristic features are the loss
of correlation through time and a particular behaviour of the average
fluctuations. Dependence on the metric is also explored. The diffusive model
that propagates correlations ballistically in the planar situation is
particularly interesting, as this propagation becomes nonuniversal in the new
regime.

categories: cond-mat.stat-mech math-ph math.MP nlin.AO


title:
Topological Graph Polynomials and Quantum Field Theory, Part I: Heat
  Kernel Theories

abstract:
  We investigate the relationship between the universal topological polynomials
for graphs in mathematics and the parametric representation of Feynman
amplitudes in quantum field theory. In this first paper we consider translation
invariant theories with the usual heat-kernel-based propagator. We show how the
Symanzik polynomials of quantum field theory are particular multivariate
versions of the Tutte polynomial, and how the new polynomials of noncommutative
quantum field theory are particular versions of the Bollob\'as-Riordan
polynomials.


title:
GEANT4 Simulation of a Cosmic Ray Muon Tomography System with
  Micro-Pattern Gas Detectors for the Detection of High-Z Materials

abstract:
  Muon Tomography (MT) based on the measurement of multiple scattering of
atmospheric cosmic ray muons traversing shipping containers is a promising
candidate for identifying threatening high-Z materials. Since
position-sensitive detectors with high spatial resolution should be
particularly suited for tracking muons in an MT application, we propose to use
compact micro-pattern gas detectors, such as Gas Electron Multipliers (GEMs),
for muon tomography. We present a detailed GEANT4 simulation of a GEM-based MT
station for various scenarios of threat material detection. Cosmic ray muon
tracks crossing the material are reconstructed with a Point-Of-Closest-Approach
algorithm to form 3D tomographic images of the target material. We investigate
acceptance, Z-discrimination capability, effects of placement of high-Z
material and shielding materials inside the cargo, and detector resolution
effects for such a MT station.


title: Probing black holes at low redshift using LISA EMRI observations

abstract:
  One of the most exciting potential sources of gravitational waves for the
Laser Interferometer Space Antenna (LISA) are the inspirals of approximately
solar mass compact objects into massive black holes in the centres of galaxies
- extreme mass ratio inspirals (EMRIs). LISA should observe between a few tens
and a few hundred EMRIs over the mission lifetime, mostly at low redshifts (z <
1). Each observation will provide a measurement of the parameters of the host
system to unprecendented precision. LISA EMRI observations will thus offer a
new and unique way to probe black holes at low redshift. In this article we
provide a description of the population of EMRI events that LISA is likely to
observe, and describe how the numbers of events vary with changes in the
underlying assumptions about the black hole population. We also provide fitting
functions that characterise LISA's ability to detect EMRIs and which will allow
LISA event rates to be computed for arbitrary population models. We finish with
a discussion of an ongoing programme that will use these results to assess what
constraints LISA observations could place on galaxy evolution models.


title: Lieb-Thirring Inequalities for Fourth-Order Operators in Low Dimensions

abstract:
  This paper considers Lieb-Thirring inequalities for higher order differential
operators. A result for general fourth-order operators on the half-line is
developed, and the trace inequality tr((-Delta)^2 - C^{HR}_{d,2} / (|x|^4) -
V(x))^{-\gamma} < C_\gamma \int_{R^d} V(x)_+^{\gamma + d/4} dx for gamma \geq 1
- d/4, where C^{HR}_{d,2} is the sharp constant in the Hardy-Rellich inequality
and where C_\gamma > 0 is independent of V, is proved for dimensions d = 1,3.
As a corollary of this inequality a Sobolev-type inequality is obtained.


title: Good formal structures on flat meromorphic connections, I: Surfaces

abstract:
  We give a criterion under which one can obtain a good decomposition (in the
sense of Malgrange) of a formal flat connection on a complex analytic or
algebraic variety of arbitrary dimension. The criterion is stated in terms of
the spectral behavior of differential operators, and generalizes Robba's
construction of the Hukuhara-Levelt-Turrittin decomposition in the
one-dimensional case. As an application, we prove the existence of good formal
structures for flat meromorphic connections on surfaces after suitable blowing
up; this verifies a conjecture of Sabbah, and extends a result of Mochizuki for
algebraic connections. Our proof uses a finiteness argument on the valuative
tree associated to a point on a surface, in order to verify the numerical
criterion.


title:
Formality of the constructible derived category for spheres: A
  combinatorial and a geometric approach

abstract:
  We describe the constructible derived category of sheaves on the $n$-sphere,
stratified in a point and its complement, as a dg module category of a formal
dg algebra. We prove formality by exploring two different methods: As a
combinatorial approach, we reformulate the problem in terms of representations
of quivers and prove formality for the 2-sphere, for coefficients in a
principal ideal domain. We give a suitable generalization of this formality
result for the 2-sphere stratified in several points and their complement. As a
geometric approach, we give a description of the underlying dg algebra in terms
of differential forms, which allows us to prove formality for $n$-spheres, for
real or complex coefficients.


title:
Groups of real analytic diffeomorphisms of the circle with a finite
  image under the rotation number function

abstract:
  We consider groups of orientation-preserving real analytic diffeomorphisms of
the circle which have a finite image under the rotation number function. We
show that if such a group is nondiscrete with respect to the $C^1$-topology
then it has a finite orbit. As a corollary, we show that if such a group has no
finite orbit then each of its subgroups contains either a cyclic group of
finite index or a nonabelian free subgroup.


title: Narrow absorptive resonances in a four-level atomic system

abstract:
  We study the effect of a control beam on a Lambda electromagnetically induced
transparency (EIT) system in 87Rb. The control beam couples one ground state to
another excited state forming a four level N-system. Phase coherent beams to
drive the N-system are produced using a double injection scheme. We show that
the control beam can be used to Stark shift or split the EIT resonance.
Finally, we show that the when the control beam is on-resonance one observes a
Doppler-free and sub-natural absorptive resonance with a width of order 100
kHz. Crucially, this narrow absorptive resonance only occurs when atoms with a
range of velocities are present, as is the case in a room temperature vapour.


title:
Linear systems over P1xP1 with base points of multiplicity bounded by
  three

abstract:
  We propose a combinatorial method of proving non-specialty of a linear system
of curves with multiple points in general positions. As an application we
obtain a classification of special linear systems on P1xP1 for which the
multiplicities do not exceed 3.


title:
First-order magnetic and structural phase transitions in
  Fe$_{1+y}$Se$_x$Te$_{1-x}$

abstract:
  We use bulk magnetic susceptibility, electronic specific heat, and neutron
scattering to study structural and magnetic phase transitions in Fe$_{1+y}$Se%
$_x$Te$_{1-x}$. Fe$_{1.068}$Te exhibits a first order phase transition near 67
K with a tetragonal to monoclinic structural transition and simultaneously
develops a collinear antiferromagnetic (AF) order responsible for the entropy
change across the transition. Systematic studies of FeSe$%_{1-x}$Te$_x$ system
reveal that the AF structure and lattice distortion in these materials are
different from those of FeAs-based pnictides. These results call into question
the conclusions of present density functional calculations, where
FeSe$_{1-x}$Te$_x$ and FeAs-based pnictides are expected to have similar Fermi
surfaces and therefore the same spin-density-wave AF order.


title: Reduced-Complexity Reed--Solomon Decoders Based on Cyclotomic FFTs

abstract:
  In this paper, we reduce the computational complexities of partial and dual
partial cyclotomic FFTs (CFFTs), which are discrete Fourier transforms where
spectral and temporal components are constrained, based on their properties as
well as a common subexpression elimination algorithm. Our partial CFFTs achieve
smaller computational complexities than previously proposed partial CFFTs.
Utilizing our CFFTs in both transform- and time-domain Reed--Solomon decoders,
we achieve significant complexity reductions.


title:
The Effects of the pep Nuclear Reaction and Other Improvements in the
  Nuclear Reaction Rate Library on Simulations of the Classical Nova Outburst

abstract:
  We have continued our studies of the Classical Nova outburst by evolving TNRs
on 1.25Msun and 1.35Msun WDs (ONeMg composition) under conditions which produce
mass ejection and a rapid increase in the emitted light, by examining the
effects of changes in the nuclear reaction rates on both the observable
features and the nucleosynthesis during the outburst. In order to improve our
calculations over previous work, we have incorporated a modern nuclear reaction
network into our hydrodynamic computer code. We find that the updates in the
nuclear reaction rate libraries change the amount of ejected mass, peak
luminosity, and the resulting nucleosynthesis. In addition, as a result of our
improvements, we discovered that the pep reaction was not included in our
previous studies of CN explosions. Although the energy production from this
reaction is not important in the Sun, the densities in WD envelopes can exceed
$10^4$ gm cm$^{-3}$ and the presence of this reaction increases the energy
generation during the time that the p-p chain is operating. The effect of the
increased energy generation is to reduce the evolution time to the peak of the
TNR and, thereby, the accreted mass as compared to the evolutionary sequences
done without this reaction included. As expected from our previous work, the
reduction in accreted mass has important consequences on the characteristics of
the resulting TNR and is discussed in this paper.


title: Toward a Holographic Model of Superconducting Fermions

abstract:
  We use the AdS/CFT correspondence to study N=4 supersymmetric SU(Nc)
Yang-Mills theory, in the limits of large Nc and large 't Hooft coupling,
coupled to a number Nf of massless hypermultiplet fields in the fundamental
representation of the gauge group. We identify a U(1) subgroup of the
R-symmetry under which the fermions in the hypermultiplet are charged but the
scalars are not. All the hypermultiplet fields are also charged under a U(1)
baryon number symmetry. We introduce an external magnetic field for the baryon
number U(1), which triggers the spontaneous breaking of the U(1) R-symmetry,
and we then introduce a chemical potential for the U(1) R-charge, producing a
state with a nonzero density of the U(1) R-charge. The system should then
exhibit superconductivity of the U(1) R-charge. The dual supergravity
description is a number Nf of D7-branes in AdS5 x S5 with angular momentum on
the S5 and a worldvolume magnetic field. We study the zero-temperature
thermodynamics of the system, and find that for sufficiently large magnetic
field the system prefers to be in the symmetry-broken phase. For smaller
magnetic fields we find a discontinuous free energy, indicating that our
gravitational setup does not capture all equilibrium states of the field
theory.


title: Tori Embedded in R3 with Dense Principal Lines

abstract:
  In this paper are given examples of tori T2 embedded in R3 with all their
principal lines dense. These examples are obtained by stereographic projection
of deformations of the Clifford torus in S3.


title:
All Possible Lightest Supersymmetric Particles in R-Parity Violating
  Minimal Supergravity Models

abstract:
  We investigate, which lightest supersymmetric particles can be obtained via a
non-vanishing lepton- or baryon-number violating operator at the grand
unification scale within the R-parity violating minimal supergravity model. We
employ the full one-loop renormalization group equations. We take into account
restrictions from the anomalous magnetic moment of the muon and b -> s gamma,
as well as collider constraints from LEP and the Tevatron. We also consider
simple deformations of minimal supergravity models.


title: The building blocks of dynamical heterogeneities in dense granular media

abstract:
  We investigate experimentally the connection between short time dynamics and
long time dynamical heterogeneities within a dense granular media under cyclic
shear. We show that dynamical heterogeneities result from a two timescales
process. Short time but already collective events consisting in clustered cage
jumps concentrate most of the non affine displacements. On larger timescales
such clusters appear aggregated both temporally and spatially in avalanches
which eventually build the large scales dynamical heterogeneities. Our results
indicate that facilitation plays an important role in the relaxation process
although it does not appear to be conserved as proposed in many models studied
in the literature.