title:
Colour Confinement, Baryon Asymmetry and Dark Matter in Quantum
  Chromodynamics

abstract:
  The concepts of local and global colour singletness in QCD are analyzed
within a framework of a group theoretical technique which can project out
various colour representations of the QGP. A proof of colour singletness is
thereby provided. This also leads to an explanation of the baryon asymmetry in
the universe within the framework of QCD itself. Supersymmetry plays a basic
role in this explanation as well as providing us with a consistent connection
between the current and the constituent picture of quarks. Glueballs as a Dark
Matter candidate manifest themselves herein. Baryonlessness of QGP is a clear
prediction of this model.


title:
An Ignored Mechanism for the Longitudinal Recoil Force in Railguns and
  Revitalization of the Riemann Force Law

abstract:
  The electric induction force due to a time-varying current is used to account
for the longitudinal recoil force exerted on the rails of railgun accelerators.
As observed in the experiments, this induction force is longitudinal to the
rails and can be the strongest at the heads of the rails. Besides, for the
force due to a closed circuit, it is shown that the Riemann force law, which is
based on a potential energy depending on a relative speed and is in accord with
Newton's law of action and reaction, can reduce to the Lorentz force law.


title:
Metastability Exchange Optical Pumping of Helium-3 at High Pressures and
  1.5 T: Comparison of two Optical Pumping Transitions

abstract:
  At low magnetic field, metastability exchange optical pumping of helium-3 is
known to provide high nuclear polarizations for pressures around 1 mbar. In a
recent paper, we demonstrated that operating at 1.5 T can significantly improve
the results of metastability exchange optical pumping at high pressures. Here,
we compare the performances of two different optical pumping lines at 1.5 T,
and show that either the achieved nuclear polarization or the production rate
can be optimized.


title: The onefold truth

abstract:
  Some features of the Schwarzschild and Kruskal metric are being discussed
under the assumption that the Schwarzschild model can be explained
geometrically.


title: Is the Bohr's quantization hypothesis necessary ?

abstract:
  We deduce the quantization of Bohr's hydrogen's atomic orbit without using
his hypothesis of angular momentum quantization. We show that his hypothesis is
nothing more than a consequence of the Planck's energy quantization.


title:
Neutral and ionic dopants in helium clusters: interaction forces for the
  $Li_2(a^3\Sigma_u^+)-He$ and $Li_2^+(X^2\Sigma_g^+)-He$

abstract:
  The potential energy surface (PES) describing the interactions between
$\mathrm{Li_{2}(^{1}\Sigma_{u}^{+})}$ and $\mathrm{^{4}He}$ and an extensive
study of the energies and structures of a set of small clusters,
$\mathrm{Li_{2}(He)_{n}}$, have been presented by us in a previous series of
publications [1-3]. In the present work we want to extend the same analysis to
the case of the excited $\mathrm{Li_{2}}(a^{3}\Sigma_{u}^{+})$ and of the
ionized Li$_{2}^{+}(X^{2}\Sigma_{g}^{+})$ moiety. We thus show here calculated
interaction potentials for the two title systems and the corresponding fitting
of the computed points. For both surfaces the MP4 method with cc-pV5Z basis
sets has been used to generate an extensive range of radial/angular coordinates
of the two dimensional PES's which describe rigid rotor molecular dopants
interacting with one He partner.


title:
Microsolvation of Li$^+$ in small He Clusters. Li$^+$He$_n$ species from
  Classical and Quantum Calculations

abstract:
  A structural study of the smaller Li$^+$He$_n$ clusters with $n\le30$ has
been carried out using different theoretical methods. The structures and the
energetics of the clusters have been obtained using both classical energy
minimization methods and quantum Diffusion Monte Carlo. The total interaction
acting within the clusters has been obtained as a sum of pairwise potentials:
Li$^+$-He and He-He. This approximation had been shown in our earlier study
\cite{8} to give substantially correct results for energies and geometries once
compared to full ab-initio calculations. The general features of the spatial
structures, and their energetics, are discussed in details for the clusters up
to $n=30$ and the first solvation shell is shown to be essentially completed by
the first ten helium atoms.


title:
The radiation of a uniformly accelerated charge is beyond the horizon: a
  simple derivation

abstract:
  We show, by exploring some elementary consequences of the covariance of
Maxwell's equations under general coordinate transformations, that, despite
inertial observers can indeed detect electromagnetic radiation emitted from a
uniformly accelerated charge, comoving observers will see only a static
electric field. This simple analysis can help understanding one of the most
celebrated paradoxes of last century.


title: Fast high--voltage amplifiers for driving electro-optic modulators

abstract:
  We describe five high-voltage (60 to 550V peak to peak), high-speed (1-300ns
rise time; 1.3-300MHz bandwidth) linear amplifiers for driving capacitive or
resistive loads such as electro-optic modulators. The amplifiers use bipolar
transistors in various topologies. Two use electron tubes to overcome the speed
limitations of high-voltage semiconductors. All amplifiers have been built.
Measured performance data is given for each.


title: Quantitive and sociological analysis of blog networks

abstract:
  This paper examines the emerging phenomenon of blogging, using three
different Polish blogging services as the base of the research. Authors show
that blog networks are sharing their characteristics with complex networks
gamma coefficients, small worlds, cliques, etc.). Elements of sociometric
analysis were used to prove existence of some social structures in the blog
networks.


title: Albert Einstein visits Argentina

abstract:
  This is a detailed, day by day, account of Albert Einstein's activities, both
social and scientific, during his 30-day stay in Argentina in 1925, including
his lectures on relativity at the various local universities and his visit to
the National Academy of Sciences, as follows from his personal Diary of the
trip to South-America and other contemporary documents.


title:
How an antenna launches its input power into radiation: the pattern of
  the Poynting vector at and near an antenna

abstract:
  In this paper I first address the question of whether the seat of the power
radiated by an antenna made of conducting members is distributed over the
``arms'' of the antenna according to -J . E, where J is the specified current
density and E is the electric field produced by that source. Poynting's theorem
permits only a global identification of the total input power, usually from a
localized generator, with the total power radiated to infinity, not a local
correspondence of -J . E dv with some specific radiated power, r^2 S . n dO. I
then describe a model antenna consisting of two perfectly conducting
hemispheres of radius a separated by a small equatorial gap across which occurs
the driving oscillatory electric field. The fields and surface current are
determined by solution of the boundary value problem. In contrast to the first
approach (not a boundary value problem), the tangential electric field vanishes
on the metallic surface. There is no radial Poynting vector normal to the
surface. Numerical examples are shown to illustrate how the energy flows from
the input region of the gap and is guided near the antenna by its ``arms''
until it is launched at larger r/a into the radiation pattern determined by the
value of ka.


title: The way back: from charge conservation to Maxwell equations

abstract:
  The main purpose of this article is to disseminate among a wide audience of
physicists a known result, which is available since a couple of years to the
\emph{cognoscenti} of differential forms on manifolds; namely, that charge
conservation implies the inhomogeneous Maxwell equations. This is the
reciprocal statement of one which is very well known among physicists: charge
conservation, written in the form of a continuity equation, follows as a
consequence of Maxwell equations. We discuss the conditions under which charge
conservation implies Maxwell equations. The key role played by the constitutive
equations is hereby stressed. The discussion is based on Helmholtz theorem,
according to which a vector field is determined by its divergence and its curl.
Green's functions are also shown to play a fundamental role. We present all
results in three-vector, as well as in tensorial notation. We employ only those
mathematical tools most physicists are familiar with.


title:
Improving on the empirical covariance matrix using truncated PCA with
  white noise residuals

abstract:
  The empirical covariance matrix is not necessarily the best estimator for the
population covariance matrix: we describe a simple method which gives better
estimates in two examples. The method models the covariance matrix using
truncated PCA with white noise residuals. Jack-knife cross-validation is used
to find the truncation that maximises the out-of-sample likelihood score.


title: Citation Statistics from 110 Years of Physical Review

abstract:
  Publicly available data reveal long-term systematic features about citation
statistics and how papers are referenced. The data also tell fascinating
citation histories of individual articles.


title: Uniaxial dielectric mediums with hyperbolic dispersion relations

abstract:
  The dispersion relations for conventional uniaxial dielectric mediums may be
characterized as elliptical or elliptical-like, according to whether the medium
is nondissipative or dissipative, respectively. However, under certain
constitutive parameter regimes, the dispersion relations may be hyperbolic or
hyperbolic-like. We investigate planewave propagation in a
hyperbolic/hyperbolic-like uniaxial dielectric medium. For both evanescent and
nonevanescent propagation, the phase velocity is found to be positive with
respect to the time-averaged Poynting vector. A conceptualization of a
hyperbolic--like uniaxial medium as a homogenized composite medium is
presented.


title: Influence of Correlated Noises on Growth of a Tumor

abstract:
  We studied the effect of additive and multiplicative noises on the growth of
a tumor based on a logistic growth model. The steady-state probability
distribution and the average population of the tumor cells were given to
explain the important roles of correlated noises in the tumor growth. We found
that multiplicative noise induces a phase transition of the tumor growth from
an uni-stable state to a bi-stable state; the relationship between the
intensity of multiplicative noise and the population of the tumor cells showed
a stochastic resonance-like characteristic. It was also confirmed that additive
noise weakened rather than extinguish the tumor growth. Homologous noises,
however, promote the growth of a tumor. We also discussed about the
relationship between the tumor treatment and the model.


title: Energy-conserving Finite-beta Electromagnetic Drift-fluid Equations

abstract:
  Nonlinear energy-conserving drift-fluid equations that are suitable to
describe self-consistent finite-beta low-frequency electromagnetic
(drift-Alfven) turbulent fluctuations in a nonuniform, anisotropic, magnetized
plasma are derived from a variational principle. The variational principle is
based on a drift-fluid Lagrangian that contains linear and nonlinear E x B
velocities derived directly from the corresponding single-particle finite-beta
gyrocenter Hamiltonian (in the zero-Larmor-radius limit). Covariant
electromagnetic effects introduce a magnetic generalization to the standard ion
polarization density as well as introduce a new ion magnetization current,
which are both missing from existing gyrofluid and drift-fluid Poisson-Ampere
equations. An exact energy conservation law is also derived directly from the
drift-fluid Lagrangian by application of the Noether method.


title: Dynamics of a bouncing dimer

abstract:
  We investigate the dynamics of a dimer bouncing on a vertically oscillated
plate. The dimer, composed of two spheres rigidly connected by a light rod,
exhibits several modes depending on initial and driving conditions. The first
excited mode has a novel horizontal drift in which one end of the dimer stays
on the plate during most of the cycle, while the other end bounces in phase
with the plate. The speed and direction of the drift depend on the aspect ratio
of the dimer. We employ event-driven simulations based on a detailed treatment
of frictional interactions between the dimer and the plate in order to
elucidate the nature of the transport mechanism in the drift mode.


title: Simultaneous cooling of axial vibrational modes in a linear ion-trap

abstract:
  In order to use a collection of trapped ions for experiments where a well
defined preparation of vibrational states is necessary, all vibrational modes
have to be cooled to ensure precise and repeatable manipulation of the ions'
quantum states. A method for simultaneous sideband cooling of all axial
vibrational modes is proposed. By application of a magnetic field gradient the
absorption spectrum of each ion is modified such that sideband resonances of
different vibrational modes coincide. The ion string is then irradiated with
monochromatic electromagnetic radiation, in the optical or microwave regime,
for sideband excitation. This cooling scheme is investigated in detailed
numerical studies. Its application for initializing ion strings for quantum
information processing is extensively discussed.


title:
Derivation of Newton's law of gravitation based on a fluidic continuum
  model of vacuum and a sink flow model of particles

abstract:
  The main purpose of this paper is to seek a mechanical interpretation of
gravitational phenomena. We suppose that the universe may be filled with a kind
of fluid which may be called the $\Omega (0)$ substratum. Thus, the
inverse-square law of gravitation is derived by methods of hydrodynamics based
on a sink flow model of particles. The first feature of this theory of
gravitation is that the gravitational interactions are transmitted by a kind of
fluidic medium. The second feature is the time dependence of gravitational
constant $G$ and gravitational mass. Newton's law of gravitation is derived if
we introduce an assumption that $G$ and the masses of particles are changing so
slowly that they can be treated as constants.


title: On Multifractal Structure in Non-Representational Art

abstract:
  Multifractal analysis techniques are applied to patterns in several abstract
expressionist artworks, paintined by various artists. The analysis is carried
out on two distinct types of structures: the physical patterns formed by a
specific color (``blobs''), as well as patterns formed by the luminance
gradient between adjacent colors (``edges''). It is found that the analysis
method applied to ``blobs'' cannot distinguish between artists of the same
movement, yielding a multifractal spectrum of dimensions between about 1.5-1.8.
The method can distinguish between different types of images, however, as
demonstrated by studying a radically different type of art. The data suggests
that the ``edge'' method can distinguish between artists in the same movement,
and is proposed to represent a toy model of visual discrimination. A ``fractal
reconstruction'' analysis technique is also applied to the images, in order to
determine whether or not a specific signature can be extracted which might
serve as a type of fingerprint for the movement. However, these results are
vague and no direct conclusions may be drawn.


title:
Deriving thermal lattice-Boltzmann models from the continuous Boltzmann
  equation: theoretical aspects

abstract:
  The particles model, the collision model, the polynomial development used for
the equilibrium distribution, the time discretization and the velocity
discretization are factors that let the lattice Boltzmann framework (LBM) far
away from its conceptual support: the continuous Boltzmann equation (BE). Most
collision models are based on the BGK, single parameter, relaxation-term
leading to constant Prandtl numbers. The polynomial expansion used for the
equilibrium distribution introduces an upper-bound in the local macroscopic
speed. Most widely used time discretization procedures give an explicit
numerical scheme with second-order time step errors. In thermal problems,
quadrature did not succeed in giving discrete velocity sets able to generate
multi-speed regular lattices. All these problems, greatly, difficult the
numerical simulation of LBM based algorithms. In present work, the systematic
derivation of lattice-Boltzmann models from the continuous Boltzmann equation
is discussed. The collision term in the linearized Boltzmann equation is
modeled by expanding the distribution function in Hermite tensors.
Thermohydrodynamic macroscopic equations are correctly retrieved with a
second-order model. Velocity discretization is the most critical step in
establishing regular-lattices framework. In the quadrature process, it is shown
that the integrating variable has an important role in defining the equilibrium
distribution and the lattice-Boltzmann model, leading, alternatively, to
temperature dependent velocities (TDV) and to temperature dependent weights
(TDW) lattice-Boltzmann models.


title:
Remarks on the conservation of mechanical energy in introductory
  mechanics

abstract:
  We discuss the work-kinetic energy theorem and the mechanical energy
conservation theorem in the context of general physics courses. The motivation
is the fact that all modern texts on introductory mechanics show the same
conceptually dangerous statement that besides obliterating the concept of
mechanical work, diminishing the importance of the work-kinetic energy theorem,
leads to erroneous applications of the energy conservation theorem and at the
same eliminates its relationship with the principle of the conservation of the
mechanical momentum.


title: Pareto index induced from the scale of companies

abstract:
  Employing profits data of Japanese companies in 2002 and 2003, we confirm
that Pareto's law and the Pareto index are derived from the law of detailed
balance and Gibrat's law. The last two laws are observed beyond the region
where Pareto's law holds. By classifying companies into job categories, we find
that companies in a small scale job category have more possibilities of growing
than those in a large scale job category. This kinematically explains that the
Pareto index for the companies in the small scale job class is larger than that
for the companies in the large scale job class.


title: Diffraction-Attenuation Resistant Beams in Absorbing Media

abstract:
  In this work, in terms of suitable superpositions of equal-frequency Bessel
beams, we develop a theoretical method to obtain nondiffractive beams in
absorbing media (weakly conductive) capable to resist the loss effects for long
distances.


title: A sound card based multi-channel frequency measurement system

abstract:
  For physical processes which express themselves as a frequency, for example
magnetic field measurements using optically-pumped alkali-vapor magnetometers,
the precise extraction of the frequency from the noisy signal is a classical
problem. We describe herein a frequency measurement system based on an
inexpensive commercially available computer sound card coupled with a software
single-tone estimator which reaches Cram\'er--Rao limited performance, a
feature which commercial frequency counters often lack. Characterization of the
system and examples of its successful application to magnetometry are
presented.


title: Fluorescence measurements of expanding strongly-coupled neutral plasmas

abstract:
  We report new detailed density profile measurements in expanding
strongly-coupled neutral plasmas. Using laser-induced fluorescence techniques,
we determine plasma densities in the range of 10^5 to 10^9/cm^3 with a time
resolution limit as small as 7 ns. Strong-coupling in the plasma ions is
inferred directly from the fluorescence signals. Evidence for strong-coupling
at late times is presented, confirming a recent theoretical result.


title: An X-ray vision of cataract

abstract:
  This work reports the exploitation of diffraction enhanced X-ray imaging
(DEI) for studying cataract in addition to the finding of heavy scattering
centers of light, probably Ca-rich precipitates in cataractous lenses. DEI
selectively probes diffuse-scattering, refraction, and absorption properties of
features in the lenses. Fiber cell compaction areas and dilute distribution of
precipitates are identifiable, as well as highly absorbing aggregations
providing contrast even in the conventional radiography setup. This finding
opens new opportunities for clinical diagnosis, for understaning the causes of
cataract, and in developing medicines for this disease.


title:
Increasing market efficiency: Evolution of cross-correlations of stock
  returns

abstract:
  We analyse the temporal changes in the cross correlations of returns on the
New York Stock Exchange. We show that lead-lag relationships between daily
returns of stocks vanished in less than twenty years. We have found that even
for high frequency data the asymmetry of time dependent cross-correlation
functions has a decreasing tendency, the position of their peaks are shifted
towards the origin while these peaks become sharper and higher, resulting in a
diminution of the Epps effect. All these findings indicate that the market
becomes increasingly efficient.


title:
On collective non-gaussian dependence patterns in high frequency
  financial data

abstract:
  The analysis of observed conditional distributions of both lagged and
simultaneous intraday price increments of a basket of stocks reveals phenomena
of dependence - induced volatility smile and kurtosis reduction. A model based
on multivariate t-Student distribution shows that the observed effects are
caused by colelctive non-gaussian dependence properties of financial time
series.


title: Variational principle for linear stability of moving magnetized plasma

abstract:
  The variational principle for linear stability of three-dimensional,
inhomogenious, compressible, moving magnetized plasma is suggested. The
principle is ``softer'' (easier to be satisfied) than all previously known
variational stability conditions. The key point of the analysis is a
conservation in variations of new integrals inherent in the linearized equation
of the motion that was not earlier discussed in the literature.


title: Statistical analysis of 22 public transport networks in Poland

abstract:
  Public transport systems in 22 Polish cities have been analyzed. Sizes of
these networks range from N=152 to N=2881. Depending on the assumed definition
of network topology the degree distribution can follow a power law or can be
described by an exponential function. Distributions of paths in all considered
networks are given by asymmetric, unimodal functions. Clustering, assortativity
and betweenness are studied. All considered networks exhibit small world
behavior and are hierarchically organized. A transition between dissortative
small networks N<=500 and assortative large networks N>=500 is observed.


title: The Pattern of Solar Wind-Magnetosphere Interaction and Its Universality

abstract:
  The multi-scale expansions and contractions of the Earth's magnetosphere
explain fundamental issues of magnetic storm-substorm relationship. This
magnetospheric behavior is in agreement with a model of
3D-spirally-faster-inward-oscillating dynamic fractal structure of the
universe. This fractal like structure accounts for the found puzzling
similarity between the near and most distant cosmos and for the calculated
fractal dimensions of the observed distributions of galaxies. The introduced
dynamic fractal dimension d(r) and formula for unifying force / F(r) = ma(r) =
constant/[r]exp(d(r)) / present new fundamental framework for qualitative and
quantitative modeling. Assessments and predictions based on the dynamic
fractals are described.


title: Rural-urban migration in d-dimensional lattices

abstract:
  The rural-urban migration phenomenon is analyzed by using an agent-based
computational model. Agents are placed on lattices which dimensions varying
from d=2 up to d=7. The localization of the agents in the lattice define their
social neighborhood (rural or urban) not being related to their spatial
distribution. The effect of the dimension of lattice is studied by analyzing
the variation of the main parameters that characterizes the migratory process.
The dynamics displays strong effects even for around one million of sites, in
higher dimensions (d=6, 7).


title: The global atmospheric electrical circuit and climate

abstract:
  Evidence is emerging for physical links among clouds, global temperatures,
the global atmospheric electrical circuit and cosmic ray ionisation. The global
circuit extends throughout the atmosphere from the planetary surface to the
lower layers of the ionosphere. Cosmic rays are the principal source of
atmospheric ions away from the continental boundary layer: the ions formed
permit a vertical conduction current to flow in the fair weather part of the
global circuit. Through the (inverse) solar modulation of cosmic rays, the
resulting columnar ionisation changes may allow the global circuit to convey a
solar influence to meteorological phenomena of the lower atmosphere. Electrical
effects on non-thunderstorm clouds have been proposed to occur via the
ion-assisted formation of ultrafine aerosol, which can grow to sizes able to
act as cloud condensation nuclei, or through the increased ice nucleation
capability of charged aerosols. Even small atmospheric electrical modulations
on the aerosol size distribution can affect cloud properties and modify the
radiative balance of the atmosphere, through changes communicated globally by
the atmospheric electrical circuit. Despite a long history of work in related
areas of geophysics, the direct and inverse relationships between the global
circuit and global climate remain largely quantitatively unexplored. From
reviewing atmospheric electrical measurements made over two centuries and
possible paleoclimate proxies, global atmospheric electrical circuit
variability should be expected on many timescales


title:
Cherenkov Radiation from $e^+e^-$ Pairs and Its Effect on $\nu_e$
  Induced Showers

abstract:
  We calculate the Cherenkov radiation from an $e^+e^-$ pair at small
separations, as occurs shortly after a pair conversion. The radiation is
reduced (compared to that from two independent particles) when the pair
separation is smaller than the wavelength of the emitted light. We estimate the
reduction in light in large electromagnetic showers, and discuss the
implications for detectors that observe Cherenkov radiation from showers in the
Earth's atmosphere, as well as in oceans and Antarctic ice.

categories: physics.class-ph hep-ph nucl-ex physics.ins-det


title: Soliton control in modulated optically-induced photonic lattices

abstract:
  We discuss soliton control in reconfigurable optically-induced photonic
lattices created by three interfering beams. We reveal novel dynamical regimes
for strongly localized solitons, including binary switching and soliton
revivals through resonant wave mixing.


title:
Avoided crossings in three coupled oscillators as a model system of
  acoustic bubbles

abstract:
  The resonance frequencies and oscillation phases of three acoustically
coupled bubbles are examined to show that avoided crossings can appear in a
multibubble system. Via a simple coupled oscillator model, we show that if at
least three bubbles exist, it is possible for their resonance frequencies as
functions of the separation distances between the bubbles to experience an
avoided crossing. Furthermore, by focusing our attention on the oscillation
phases and based on analysis of the transition frequencies [M. Ida, Phys. Lett.
A 297, 210 (2002); M. Ida, J. Phys. Soc. Jpn. 71, 1214 (2002)] of the coupled
bubbles, we show that a distinct state exchange takes place between the bubbles
at a point in the avoided crossing region, where a resonance frequency of the
triple-bubble system crosses with a transition frequency not corresponding to
the resonance frequencies.


title:
Transversal plasma resonance in a nonmagnetized plasma and possibilities
  of practical employment of it

abstract:
  It is shown that in a nonmagnetized plasma, beside the longitudinal Langmuir
resonance, there may also exist the transversal resonance. Both these resonance
kinds are degenerated. Employment of the transversal resonance makes it
possible to design resonators and filters, as well as powerful single-frequency
lasers operating on the basis of collective oscillations of plasma.


title: The theory of pinch-effect in the concept scalar-vector potential

abstract:
  In the paper, on the basis of a new concept of the scalar-vector potential
introduced by the author, mechanisms resulting in the plasma pinching are
considered.


title:
Conception of the scalar-vector potential in contemporary
  electrodynamics

abstract:
  The present paper is devoted to consideration and discussion of a number of
contradictions that take place in fundamental electrodynamics researches. A
concept of the scalar-vector potential is introduced that allows us to avoid a
number of challenges taking place in treatment of forces of elecrtromagnetic
interaction. It is introduced the delayed scalar-vector potential allowing one
to solve radiation problems at an elementary level. It is shown that in a
nonmagnetized plasma, beside the earlier known longitudinal Langmuir resonance,
there may exist a resonance transversal relative to the wave propagation
direction. It is also shown that the dielectric and magnetic permittivities are
independent on the frequency. It is introduced a concept of the kinetic
capacitance.


title: mFOAM-1.02: A Compact Version of the Cellular Event Generator FOAM

abstract:
  The general-purpose self-adapting Monte Carlo (MC) event generator/simulator
mFOAM (standing for mini-FOAM) is a new compact version of the FOAM program,
with a slightly limited functionality with respect to its parent version. On
the other hand, mFOAM is easier to use for the average user. This new version
is fully integrated with the ROOT package, the C++ utility library used widely
in the particle physics community. The internal structure of the code is
simplified and the very valuable feature of the persistency of the objects of
the mFOAM class is improved. With the persistency at hand, it is possible to
record very easily the complete state of a MC simulator object based on mFOAM
and ROOT into a disk-file at any stage of its use: just after object
allocation, after full initialization (exploration of the distribution), or at
any time during the generation of the long series of MC events. Later on the MC
simulator object can be easily restored from the disk-file in the ``ready to
go'' state. Objects of TFoam class can be used as a stand-alone solution to
many everyday problems in the area of the Monte Carlo simulation, or as
building blocks in large-scale MC projects, taking full advantage of the
object-oriented technology and persistency.


title: Habitable sphere and fine structure constant

abstract:
  Future space missions, TPF and Darwin will focus on searches of signatures of
life on extrasolar planets. In this paper we look for model independ definition
of the habitable zone. It will be shown that the radius of the habitable sphere
depends only on the constants of the Nature.
  Key words: Habitable sphere, fine structure constant.


title: Economics: The next physical science?

abstract:
  We review an emerging body of work by physicists addressing questions of
economic organization and function. We suggest that, beyond simply employing
models familiar from physics to economic observables, remarkable regularities
in economic data may suggest parts of social order that can usefully be
incorporated into, and in turn can broaden, the conceptual structure of
physics.


title:
Three-Dimensional FDTD Simulation of Biomaterial Exposure to
  Electromagnetic Nanopulses

abstract:
  Ultra-wideband (UWB) electromagnetic pulses of nanosecond duration, or
nanopulses, have been recently approved by the Federal Communications
Commission for a number of various applications. They are also being explored
for applications in biotechnology and medicine. The simulation of the
propagation of a nanopulse through biological matter, previously performed
using a two-dimensional finite difference-time domain method (FDTD), has been
extended here into a full three-dimensional computation. To account for the UWB
frequency range, a geometrical resolution of the exposed sample was $0.25 mm$,
and the dielectric properties of biological matter were accurately described in
terms of the Debye model. The results obtained from three-dimensional
computation support the previously obtained results: the electromagnetic field
inside a biological tissue depends on the incident pulse rise time and width,
with increased importance of the rise time as the conductivity increases; no
thermal effects are possible for the low pulse repetition rates, supported by
recent experiments. New results show that the dielectric sample exposed to
nanopulses behaves as a dielectric resonator. For a sample in a cuvette, we
obtained the dominant resonant frequency and the $Q$-factor of the resonator.


title:
Cancellation exponent and multifractal structure in two-dimensional
  magnetohydrodynamics: direct numerical simulations and Lagrangian averaged
  modeling

abstract:
  We present direct numerical simulations and Lagrangian averaged (also known
as alpha-model) simulations of forced and free decaying magnetohydrodynamic
turbulence in two dimensions. The statistics of sign cancellations of the
current at small scales is studied using both the cancellation exponent and the
fractal dimension of the structures. The alpha-model is found to have the same
scaling behavior between positive and negative contributions as the direct
numerical simulations. The alpha-model is also able to reproduce the time
evolution of these quantities in free decaying turbulence. At large Reynolds
numbers, an independence of the cancellation exponent with the Reynolds numbers
is observed.


title:
Cavity-enhanced single frequency synthesis via DFG of mode-locked pulse
  trains

abstract:
  We show how to synthesize a CW, single-frequency optical field from the
frequency-dispersed, pulsed field of a mode-locked laser. This process, which
relies on difference frequency generation in an optical cavity, is efficient
and can be considered as an optical rectification. Quantitative estimates for
the output power and amplitude noise properties of a realistic system are
given. Possible applications to optical frequency synthesis and optical
metrology are envisaged.


title: Analysis of a Material Phase Shifting Element in an Atom Interferometer

abstract:
  The interaction of Na atoms with a surface was probed by inserting a
nanofabricated material grating into one arm of an atom interferometer (IFM).
This technique permits a direct measurement of the change in phase and
coherence of matter waves as they pass within 25 nm of the grating bar surface.
The practical concerns and challenges of making such a measurement are
discussed here. Interference of spurious diffraction orders, IFM path overlap,
and the partial obscuration of IFM beams are all important aspects of this
experiment. The systematic effects that contribute to the measured phase shift
and contrast are discussed.


title: Discrete interband mutual focusing in nonlinear photonic lattices

abstract:
  We study nonlinear coupling of mutually incoherent beams associated with
different Floquet-Bloch waves in a one-dimensional optically-induced photonic
lattice. We demonstrate experimentally how such interactions lead to asymmetric
mutual focusing and, for waves with opposite diffraction properties, to
simultaneous focusing and defocusing as well as discreteness-induced beam
localization and reshaping effects.


title: Second-harmonic generation in nonlinear left-handed metamaterials

abstract:
  We study the second-harmonic generation in left-handed metamaterials with a
quadratic nonlinear response. We demonstrate a novel type of the exact phase
matching between the backward propagating wave of the fundamental frequency and
the forward propagating wave of the second harmonics. We show that this novel
parametric process can convert a surface of the left-handed metamaterial into
an effective mirror totally reflecting the second harmonics generated by an
incident wave. We derive and analyze theoretically the coupled-mode equations
for a semi-infinite nonlinear metamaterial. We also study numerically the
second-harmonic generation by a metamaterial slab of a finite thickness, and
reveal the existence of multistable nonlinear effects.


title:
Upper limit of the energy of the photon and the phase change of photon
  to material particles at the Scwartzschild radius

abstract:
  The concept of Scwartzschild radius is extended to the photon and the upper
limit imposed on the energy of a photon as a result of the three
characteristics of the photon--the constancy of the velocity of light, the spin
value of $1\hslash$ and the zero rest mass of the photon--is shown. Further the
phase change that occurs to the photon at the Scwartzschild radius, from energy
to matter as a result of vacuum fluctuations is indicated.


title: Synchronization of organ pipes: experimental observations and modeling

abstract:
  We report measurements on the synchronization properties of organ pipes.
First, we investigate influence of an external acoustical signal from a
loudspeaker on the sound of an organ pipe. Second, the mutual influence of two
pipes with different pitch is analyzed. In analogy to the externally driven, or
mutually coupled self-sustained oscillators, one observes a frequency locking,
which can be explained by synchronization theory. Further, we measure the
dependence of the frequency of the signals emitted by two mutually detuned
pipes with varying distance between the pipes. The spectrum shows a broad
``hump'' structure, not found for coupled oscillators. This indicates a complex
coupling of the two organ pipes leading to nonlinear beat phenomena.

categories: physics.class-ph nlin.AO nlin.CD nlin.PS


title: Transient deformations in the Suez-Sinai area from GPS observations

abstract:
  We analyze data from four GPS campaigns carried out between 1997 and 2002 on
a network of 11 sites in the Suez-Sinai, the area of collision between the
African and the Arabian plates. This is the key area to understand how and in
which way Sinai behaves like a sub-plate of the African plate and the role
played between seismic and geodetic (long term) deformation release. Our
analysis shows that, on average, the Suez-Sinai area motion (in terms of ITRF00
velocities) matches African plate motion (NNR-NUVEL-1A model). However, the
baseline length variations show transient deformations in Sinai and across the
Gulf of Suez, reaching up a maximum value of about 1.5 cm in five years. Since
current geodynamical models do not predict significant tectonic deformation in
this area, we worked under the hypothesis that a contribute may be due to
post-seismic relaxation. Under this hypothesis, we compared the baselines
length variations with the post-seismic relaxation field associated with five
major local earthquakes occurred in the area, testing two different
viscoelastic models. Our results show that the transient deformations are
better modelled for viscosity values of 1018 Pa s in the lower crust and 1020
Pa s in the asthenosphere. However, since the modelled post-seismic effect
results modest and a certain amount of the detected deformation is not
accounted for, we think that an improved modelling should take into account the
lateral heterogeneities of crust and upper mantle structures.


title:
Boundary value problems and the validity of the Post constraint in
  modern electromagnetism

abstract:
  When a (frequency-domain) boundary value problem involving a homogeneous
linear material is solved to assess the validity of the Post constraint, a
conflict arises between the fundamental differential equations of
electromagnetism in the chosen material and a naive application of the usual
boundary conditions. It is shown here that the conflict vanishes when the
boundary conditions are properly derived from the fundamental equations, and
the validity of the Post constraint in modern macroscopic electromagnetism is
thereby reaffirmed.


title: Transmission matrix of a uniaxial optically active crystal platelet

abstract:
  Expressions corresponding to the transmission of a uniaxial optically active
crystal platelet are provided for an optical axis parallel and perpendicular to
the plane of interface. The optical activity is taken into account by a
consistent multipolar expansion of the crystal medium response due to the path
of an electromagnetic wave. Numerical examples of the effect of the optical
activity are given for quartz platelets of chosen thicknesses. The optical
activity's effects on the variations of the transmission of quartz platelets as
a function of the angle of incidence is also investigated.


title: Stock mechanics: predicting recession in S&P500, DJIA, and NASDAQ

abstract:
  An original method, assuming potential and kinetic energy for prices and
conservation of their sum is developed for forecasting exchanges. Connections
with power law are shown. Semiempirical applications on S&P500, DJIA, and
NASDAQ predict a coming recession in them. An emerging market, Istanbul Stock
Exchange index ISE-100 is found involving a potential to continue to rise.


title:
Statistical properties of an ensemble of vortices interacting with a
  turbulent field

abstract:
  We develop an analytical formalism to determine the statistical properties of
a system consisting of an ensemble of vortices with random position in plane
interacting with a turbulent field. We calculate the generating functional by
path-integral methods. The function space is the statistical ensemble composed
of two parts, the first one representing the vortices influenced by the
turbulence and the second one the turbulent field scattered by the randomly
placed vortices.


title: Do we really need the weight force?

abstract:
  In 1901 the third Conference Generale des Poids et Mesures (CGPM) defined the
weight of a body as ``the product of its mass and the acceleration due to
gravity". In practical terms the weight force corresponds to the gravitational
force. However, this gravitational definition of the weight lacks logic from
the perspective of present knowledge and can be misleading. In a space
traveling time, weight associated concepts such as "true weight", "apparent
weight", "weightlessness", "zero gravity", "microgravity", are ambiguous and
strong deceptive. The superfluousness or ambiguousness of these concept would
be removed if an operational definition of the weight of a body as the force
the body exerts on its support or suspender is adopted. In this definition the
weight force does not act on the body and it is not necessary to describe the
body's sate of motion. This avoids the imprecision of the concepts such as
"true weight" and "apparent weight" of a body, for example. This paper
discusses the need of the weight force of a body concept in Physics, and asks
for a re-exame of the CGPM definition to improve the physics teaching and
learning.


title:
Underlying Dynamics of Typical Fluctuations of an Emerging Market Price
  Index: The Heston Model from Minutes to Months

abstract:
  We investigate the Heston model with stochastic volatility and exponential
tails as a model for the typical price fluctuations of the Brazilian S\~ao
Paulo Stock Exchange Index (IBOVESPA). Raw prices are first corrected for
inflation and a period spanning 15 years characterized by memoryless returns is
chosen for the analysis. Model parameters are estimated by observing volatility
scaling and correlation properties. We show that the Heston model with at least
two time scales for the volatility mean reverting dynamics satisfactorily
describes price fluctuations ranging from time scales larger than 20 minutes to
160 days. At time scales shorter than 20 minutes we observe autocorrelated
returns and power law tails incompatible with the Heston model. Despite major
regulatory changes, hyperinflation and currency crises experienced by the
Brazilian market in the period studied, the general success of the description
provided may be regarded as an evidence for a general underlying dynamics of
price fluctuations at intermediate mesoeconomic time scales well approximated
by the Heston model. We also notice that the connection between the Heston
model and Ehrenfest urn models could be exploited for bringing new insights
into the microeconomic market mechanics.


title:
Coupled-mode theory for periodic side-coupled microcavity and photonic
  crystal structures

abstract:
  We use a phenomenological Hamiltonian approach to derive a set of coupled
mode equations that describe light propagation in waveguides that are
periodically side-coupled to microcavities. The structure exhibits both Bragg
gap and (polariton like) resonator gap in the dispersion relation. The origin
and physical significance of the two types of gaps are discussed. The
coupled-mode equations derived from the effective field formalism are valid
deep within the Bragg gaps and resonator gaps.


title:
Boltzmann-Gibbs Distribution of Fortune and Broken Time-Reversible
  Symmetry in Econodynamics

abstract:
  Within the description of stochastic differential equations it is argued that
the existence of Boltzmann-Gibbs type distribution in economy is independent of
the time reversal symmetry in econodynamics. Both power law and exponential
distributions can be accommodated by it. The demonstration is based on a
mathematical structure discovered during a study in gene regulatory network
dynamics. Further possible analogy between equilibrium economy and
thermodynamics is explored.


title:
Long range scattering resonances in strong-field seeking states of polar
  molecules

abstract:
  We present first steps toward understanding the ultracold scattering
properties of polar molecules in strong electric field-seeking states. We have
found that the elastic cross section displays a quasi-regular set of potential
resonances as a function of the electric field, which potentially offers
intimate details about the inter-molecular interaction. We illustrate these
resonances in a ``toy'' model composed of pure dipoles, and in more physically
realistic systems. To analyze these resonances, we use a simple WKB
approximation to the eigenphase, which proves both reasonably accurate and
meaningful. A general treatment of the Stark effect and dipolar interactions is
also presented.


title:
Photoluminescence measurements of quantum-dot-containing semiconductor
  microdisk resonators using optical fiber taper waveguides

abstract:
  Fiber taper waveguides are used to improve the efficiency of room temperature
photoluminescence measurements of AlGaAs microdisk resonant cavities with
embedded self-assembled InAs quantum dots. As a near-field collection optic,
the fiber taper improves the collection efficiency from microdisk lasers by a
factor of ~ 15-100 times in comparison to conventional normal incidence
free-space collection techniques. In addition, the fiber taper can serve as a
efficient means for pumping these devices, and initial measurements employing
fiber pumping and collection are presented. Implications of this work towards
chip-based cavity quantum electrodynamics experiments are discussed.


title: Discrete Simulation of the Dynamics of Opinions about Extremism

abstract:
  We propose a discrete model for how opinion about a given phenomenon, about
which various groups of a population have different degrees of enthusiasm, such
as fanaticism and extreme social and political positions, including terrorism,
may spread. The model, in a certain limit, is the discrete analogue of a
deterministic continuum model suggested by others. We carry out extensive
computer simulation of the model by utilizing it on lattices with infinite- or
short-range interactions, and on (directed) Barabasi-Albert scale-free
networks. Several interesting features of the model are demonstrated, and
comparison is made with the continuum model.


title: Activation entropy of electron transfer reactions

abstract:
  We report microscopic calculations of free energies and entropies for
intramolecular electron transfer reactions. The calculation algorithm combines
the atomistic geometry and charge distribution of a molecular solute obtained
from quantum calculations with the microscopic polarization response of a polar
solvent expressed in terms of its polarization structure factors. The procedure
is tested on a donor-acceptor complex in which ruthenium donor and cobalt
acceptor sites are linked by a four-proline polypeptide. The reorganization
energies and reaction energy gaps are calculated as a function of temperature
by using structure factors obtained from our analytical procedure and from
computer simulations. Good agreement between two procedures and with direct
computer simulations of the reorganization energy is achieved. The microscopic
algorithm is compared to the dielectric continuum calculations. We found that
the strong dependence of the reorganization energy on the solvent refractive
index predicted by continuum models is not supported by the microscopic theory.
Also, the reorganization and overall solvation entropies are substantially
larger in the microscopic theory compared to continuum models.


title: Determinism and Indeterminism

abstract:
  Determinism and indeterminism in physical theories are reviewed and some
broader implications of determinism are discussed.


title:
Expressions for the Exchange Correlation Potential and Exchange
  Correlation Functional of Kohn--Sham Density Functional Theory

abstract:
  The State--Specific Kohn--Sham Density Functional Theory
[arXiv:physics/0506037] is used to derive the Kohn-Sham exchange-correlation
potential $\vxc$ and exchange-correlation energy $\Eco$ as explicit functionals
of $v_s$ and $\phi_1$, where $v_s$ is the local, one-body potential from the
Kohn--Sham equations, and $\phi_1$ is the spinless one-particle density matrix
from the Kohn--Sham noninteracting state, say $|\phi_1\ran$. In other words,
$|\phi_1\ran$ is the ground state eigenfunction of the noninteracting
Schr\"odinger equation with the one-body potential $v_s$. For simplicity, we
only consider noninteracting states that are closed-shell states and
interacting states that are nondegenerate, singlet ground-states.


title: The "Thermodynamic" Universe

abstract:
  Much of the twentieth century physics has considered rigid laws-- even
Quantum Mechanics and Statistical Mechanics were based on such laws. These laws
operated in a smooth spacetime manifold. However more recent approaches as in
Quantum Gravity schemes or Quantum Super String theory deal with a non
differentiable spacetime manifold. With this we have to consider the new
paradigm of Dark Energy of Zero Point Field. The picture that now emerges is
that of a universe that is ``Thermodynamic''. We investigate how this can
explain phenomenon like the velocity of light and also provide tests for
experimental verification.


title:
A Novel General Theoretical Derivation of Newton-Experimental-Formula
  for Collision of Particles

abstract:
  An experimental formula, sometimes named as Newton-collision-formula, (v1-v2)
= - e.(u1-u2) relating relative-velocities before & after impact of two bodies
under linear-collision, is commonly used successfully for study of
collision-dynamics. Although it seems possible as shown in text-books [1,2] to
derive this relation, assuming (defining) e as ratio of impulses during
restitution & deformation; but as yet, neither a good theoretical-basis nor a
general-derivation of this formula based on obvious choice of
energy-consideration, has been reported. In this brief-paper a
relativistic-theoretical-basis is adopted and a general formula-derivation is
given. It is shown, interestingly, that proof of the Newton-collision-formula
is hidden in Einstein-special-relativity.


title: Geometrical aspects of first-order optical systems

abstract:
  We reconsider the basic properties of ray-transfer matrices for first-order
optical systems from a geometrical viewpoint. In the paraxial regime of scalar
wave optics, there is a wide family of beams for which the action of a
ray-transfer matrix can be fully represented as a bilinear transformation on
the upper complex half-plane, which is the hyperbolic plane. Alternatively,
this action can be also viewed in the unit disc. In both cases, we use a simple
trace criterion that arranges all first-order systems in three classes with a
clear geometrical meaning: they represent rotations, translations, or parallel
displacements. We analyze in detail the relevant example of an optical
resonator.


title:
Laser nanotraps and nanotweezers for cold atoms: 3D gradient dipole
  force trap in the vicinity of Scanning Near-field Optical Microscope tip

abstract:
  Using a two-dipole model of an optical near-field of Scanning Near-field
Optical Microscope tip, i. e. taking into account contributions of magnetic and
electric dipoles, we propose and analyze a new type of 3D optical nanotrap
found for certain relations between electric and magnetic dipoles. Electric
field attains a minimum value in vacuum in the vicinity of the tip and hence
such a trap is quite suitable for manipulations with cold atoms.


title:
Comparison of volatility distributions in the periods of booms and
  stagnations: an empirical study on stock price indices

abstract:
  The aim of this paper is to compare statistical properties of stock price
indices in periods of booms with those in periods of stagnations. We use the
daily data of the four stock price indices in the major stock markets in the
world: (i) the Nikkei 225 index (Nikkei 225) from January 4, 1975 to August 18,
2004, of (ii) the Dow Jones Industrial Average (DJIA) from January 2, 1946 to
August 18, 2004, of (iii) Standard and Poor's 500 index (SP500) from November
22, 1982 to August 18, 2004, and of (iii) the Financial Times Stock Exchange
100 index (FT 100) from April 2, 1984 to August 18, 2004. We divide the time
series of each of these indices in the two periods: booms and stagnations, and
investigate the statistical properties of absolute log returns, which is a
typical measure of volatility, for each period. We find that (i) the tail of
the distribution of the absolute log-returns is approximated by a power-law
function with the exponent close to 3 in the periods of booms while the
distribution is described by an exponential function with the scale parameter
close to unity in the periods of stagnations.


title: Measuring the Beam Energy with Radiative Return Events

abstract:
  This paper studies the possibility to measure the centre of mass energy using
e+e- -> Z,gamma -> mu+mu-,gamma events at the ILC. With L = 100 fb^-1 at
sqrt(s) = 350 GeV a relative error of around 10^{-4} is possible. The
potentially largest systematic uncertainty comes from the knowledge of the
aspect ratio of the detector.


title:
Persistence in a Simple Model for the Earth's Atmosphere Temperature
  Fluctuations

abstract:
  The effect caused by the presence of a number of distinct time scales in a
simple stochastic model for the Earth's atmosphere temperature fluctuations is
studied. The model is described by a dissipative dynamics consisting of a set
of coupled stochastic evolution equations. The system shows features that
resemble recent observations. In contrast to other approaches, like
autoregressive models, the fluctuations of the atmosphere's temperature depend
on parameters with clear physical meaning. A reduced version of the model is
constructed and its temporal autocovariance function is explicitly written.


title:
Estimation of coupling between oscillators from short time series via
  phase dynamics modeling: limitations and application to EEG data

abstract:
  We demonstrate in numerical experiments that estimators of strength and
directionality of coupling between oscillators based on modeling of their phase
dynamics [D.A. Smirnov and B.P. Bezruchko, Phys. Rev. E 68, 046209 (2003)] are
widely applicable. Namely, although the expressions for the estimators and
their confidence bands are derived for linear uncoupled oscillators under the
influence of independent sources of Gaussian white noise, they turn out to
allow reliable characterization of coupling from relatively short time series
for different properties of noise, significant phase nonlinearity of the
oscillators, and non-vanishing coupling between them. We apply the estimators
to analyze a two-channel human intracranial epileptic electroencephalogram
(EEG) recording with the purpose of epileptic focus localization.


title: Indoor Sonic Boom Reproduction Using ANC

abstract:
  The European programs for development of supersonic air-flights involve new
studies on the human perception of sonic boom. Because this noise includes
high-level components at very low-frequency, the usual psycho-acoustic tests
with headphones are not relevant; instead, the original sound-field can be
reproduced with many loudspeakers in a small room, but the loudspeakers must be
controlled for an accurate reproduction, both in time and space, in an area
large enough to enclose a listener's head. In this paper, Active Noise Control
is applied to sonic boom reproduction through Boundary Surface Control (as
named by S.Ise) of the acoustic pressure around a listener. A small room was
built at LMA with sixteen powerful low-frequency acoustic sources in the walls.
Frequency and time-domain numerical simulations of sonic boom reproduction in
this room are given, including a sensitivity study of the coupling between a
listener's head and the incident sonic boom wave which combine into the
effective sound-field to be reproduced.


title: Time dependence of laser cooling in optical lattices

abstract:
  We study the dynamics of the cooling of a gas of caesium atoms in an optical
lattice, both experimentally and with 1D full-quantum Monte Carlo simulations.
We find that, contrary to the standard interpretation of the Sisyphus model,
the cooling process does not work by a continuous decrease of the average
kinetic energy of the atoms in the lattice. Instead, we show that the momentum
of the atoms follows a bimodal distribution, the atoms being gradually
transferred from a hot to a cold mode. We suggest that the cooling mechanism
should be depicted in terms of a rate model, describing the transfer between
the two modes along with the processes occurring within each mode.


title: Bessel beam propagation: Energy localization and velocity

abstract:
  The propagation of a Bessel beam (or Bessel-X wave) is analyzed on the basis
of a vectorial treatment. The electric and magnetic fields are obtained by
considering a realistic situation able to generate that kind of scalar field.
Specifically, we analyze the field due to a ring-shaped aperture over a
metallic screen on which a linearly polarized plane wave impinges. On this
basis, and in the far field approximation, we can obtain information about the
propagation of energy flux and the velocity of the energy.


title:
Optical absorption by magnesia-supported gold clusters and
  nanocatalysts: effects from the support, cluster and adsorbants

abstract:
  Polarization-resolved optical spectra of magnesia-supported gold clusters
Au$_N$/MgO (N=1,2,4,8), bound at a surface color center $F_s$ of the MgO(100)
face, are calculated from the time-dependent density functional theory. The
optical lines for n=1,2 are dominated by transitions that involve strong
hybridization between gold and $F_s$ states whereas for n=4,8 intracluster
transitions dominate. The theoretical optical spectra are sensitive to cluster
structure and adsorbants (here CO and O$_2$ molecules on Au$_8$/MgO) which
suggests polarization-resolved optical spectroscopy as a powerful tool to
investigate structures and functions of chemically active, supported clusters.


title: Network Marketing on a Small-World Network

abstract:
  We investigate a dynamic model of network marketing in a small-world network
structure artificially constructed similarly to the Watts-Strogatz network
model. Different from the traditional marketing, consumers can also play the
role of the manufacturer's selling agents in network marketing, which is
stimulated by the referral fee the manufacturer offers. As the wiring
probability $\alpha$ is increased from zero to unity, the network changes from
the one-dimensional regular directed network to the star network where all but
one player are connected to one consumer. The price $p$ of the product and the
referral fee $r$ are used as free parameters to maximize the profit of the
manufacturer. It is observed that at $\alpha=0$ the maximized profit is
constant independent of the network size $N$ while at $\alpha \neq 0$, it
increases linearly with $N$. This is in parallel to the small-world transition.
It is also revealed that while the optimal value of $p$ stays at an almost
constant level in a broad range of $\alpha$, that of $r$ is sensitive to a
change in the network structure. The consumer surplus is also studied and
discussed.


title: Superstatistical turbulence models

abstract:
  Recently there has been some progress in modeling the statistical properties
of turbulent flows using simple superstatistical models. Here we briefly review
the concept of superstatistics in turbulence. In particular, we discuss a
superstatistical extension of the Sawford model and compare with experimental
data.


title: Electronic filaments

abstract:
  In the one-dimensional world of a flux line beyond Bce, paired evanescent low
momentum 0-Landau electron states condense into magnetized bosons of vanishing
momentum. I use the results of Rojas et al. within a Coulomb potential and show
that magnetic intensities and electron densities sufficient to initiate
condensation can be achieved in the shockwaves of cathode hot spots; from
unipolar pulses on the surface of a discontinuous micro conductor or cathode
tip as a discharge suddenly self-interrupts. Above Bc_e, there are charged
electronic vector states that are superconducting and ferromagnetic. Assuming
the magnetization of the vacuum within the flux quantized to be free extends
the range of stable states. The thinnest filaments have the Compton radius for
the effective boson mass. When perturbed,they evolve towards a decaying state
with vanishing density at Bc or further condense into composites of higher
mass, charge and critical field. Open, almost neutral filament systems with one
quantum of flux and several microns in length would be metastable in the
Earth's magnetic field and terminated by magnetic monopoles.


title: A Model of Proton

abstract:
  I suggest to consider a proton as a body in a state of free precession. Such
approach allows to define a proton as periodic system with two rotary degrees
of freedom with corresponding frequency ratio and resonances. In result on a
power scale the points corresponding to a birth of leptons are designated. The
interrelation between masses of leptons is established through a fine structure
constant. The given approach is distributed to a nucleus. Other representation
is given on the nature of X-rays which connect with a charge of a nucleus and
its mass.


title: Exact results for the Barabasi model of human dynamics

abstract:
  Human activity patterns display a bursty dynamics, with interevent times
following a heavy tailed distribution. This behavior has been recently shown to
be rooted in the fact that humans assign their active tasks different
priorities, a process that can be modeled as a priority queueing system [A.-L.
Barabasi, Nature 435, 207 (2005)]. In this work we obtain exact results for the
Barabasi model with two tasks, calculating the priority and waiting time
distribution of active tasks. We demonstrate that the model has a singular
behavior in the extremal dynamics limit, when the highest priority task is
selected first. We find that independently of the selection protocol, the
average waiting time is smaller or equal to the number of active tasks, and
discuss the asymptotic behavior of the waiting time distribution. These results
have important implications for understanding complex systems with extremal
dynamics.


title: Elasticity Theory and Shape Transitions of Viral Shells

abstract:
  Recently, continuum elasticity theory has been applied to explain the shape
transition of icosahedral viral capsids - single-protein-thick crystalline
shells - from spherical to buckled/faceted as their radius increases through a
critical value determined by the competition between stretching and bending
energies of a closed 2D elastic network. In the present work we generalize this
approach to capsids with non-icosahedral symmetries, e.g., spherocylindrical
and conical shells. One key new physical ingredient is the role played by
nonzero spontaneous curvature. Another is associated with the special way in
which the energy of the twelve topologically-required five-fold sites depends
on the background local curvature of the shell in which they are embedded.
Systematic evaluation of these contributions leads to a shape phase diagram in
which transitions are observed from icosahedral to spherocylindrical capsids as
a function of the ratio of stretching to bending energies and of the
spontaneous curvature of the 2D protein network. We find that the transition
from icosahedral to spherocylindrical symmetry is continuous or weakly
first-order near the onset of buckling, leading to extensive shape degeneracy.
These results are discussed in the context of experimentally observed
variations in the shapes of a variety of viral capsids.


title: The Indefinite Logarithm, Logarithmic Units, and the Nature of Entropy

abstract:
  We define the indefinite logarithm [log x] of a real number x>0 to be a
mathematical object representing the abstract concept of the logarithm of x
with an indeterminate base (i.e., not specifically e, 10, 2, or any fixed
number). The resulting indefinite logarithmic quantities naturally play a
mathematical role that is closely analogous to that of dimensional physical
quantities (such as length) in that, although these quantities have no definite
interpretation as ordinary numbers, nevertheless the ratio of two of these
entities is naturally well-defined as a specific, ordinary number, just like
the ratio of two lengths. As a result, indefinite logarithm objects can serve
as the basis for logarithmic spaces, which are natural systems of logarithmic
units suitable for measuring any quantity defined on a logarithmic scale. We
illustrate how logarithmic units provide a convenient language for explaining
the complete conceptual unification of the disparate systems of units that are
presently used for a variety of quantities that are conventionally considered
distinct, such as, in particular, physical entropy and information-theoretic
entropy.


title:
Anisotropic enhancement of group velocity in a homogenized dielectric
  composite medium

abstract:
  Under certain circumstances, the group velocity in a homogenized composite
medium (HCM) can exceed the group velocity in its component material phases. We
explore this phenomenon for a uniaxial dielectric HCM comprising isotropic
component material phases distributed as oriented spheroidal particles. The
theoretical approach is based upon the Bruggeman homogenization formalism.
Enhancement in group velocity in the HCM with respect to the component material
phases is shown to be sensitively dependent upon the shape of the component
spheroids and their alignment relative to the direction of propagation.


title: H-theorem for classical matter around a black hole

abstract:
  We propose a classical solution for the kinetic description of matter falling
into a black hole, which permits to evaluate both the kinetic entropy and the
entropy production rate of classical infalling matter at the event horizon. The
formulation is based on a relativistic kinetic description for classical
particles in the presence of an event horizon. An H-theorem is established
which holds for arbitrary models of black holes and is valid also in the
presence of contracting event horizons.


title:
On electromagnetic boundary conditions and constitution of homogeneous
  materials

abstract:
  Constitutive scalars that are absent in the fundamental differential
equations of frequency-domain electromagnetism on the two sides of a boundary
between two homogeneous mediums are shown to disappear from the boundary
conditions as well.


title: The Cleo Rich Detector

abstract:
  We describe the design, construction and performance of a Ring Imaging
Cherenkov Detector (RICH) constructed to identify charged particles in the CLEO
experiment. Cherenkov radiation occurs in LiF crystals, both planar and ones
with a novel ``sawtooth''-shaped exit surface. Photons in the wavelength
interval 135--165 nm are detected using multi-wire chambers filled with a
mixture of methane gas and triethylamine vapor. Excellent pion/kaon separation
is demonstrated.


title:
Uncovering the overlapping community structure of complex networks in
  nature and society

abstract:
  Many complex systems in nature and society can be described in terms of
networks capturing the intricate web of connections among the units they are
made of. A key question is how to interpret the global organization of such
networks as the coexistence of their structural subunits (communities)
associated with more highly interconnected parts. Identifying these a priori
unknown building blocks (such as functionally related proteins, industrial
sectors and groups of people) is crucial to the understanding of the structural
and functional properties of networks. The existing deterministic methods used
for large networks find separated communities, whereas most of the actual
networks are made of highly overlapping cohesive groups of nodes. Here we
introduce an approach to analysing the main statistical features of the
interwoven sets of overlapping communities that makes a step towards uncovering
the modular structure of complex systems. After defining a set of new
characteristic quantities for the statistics of communities, we apply an
efficient technique for exploring overlapping communities on a large scale. We
find that overlaps are significant, and the distributions we introduce reveal
universal features of networks. Our studies of collaboration, word-association
and protein interaction graphs show that the web of communities has non-trivial
correlations and specific scaling properties.


title: Using Artificial Market Models to Forecast Financial Time-Series

abstract:
  We discuss the theoretical machinery involved in predicting financial market
movements using an artificial market model which has been trained on real
financial data. This approach to market prediction - in particular, forecasting
financial time-series by training a third-party or 'black box' game on the
financial data itself -- was discussed by Johnson et al. in cond-mat/0105303
and cond-mat/0105258 and was based on some encouraging preliminary
investigations of the dollar-yen exchange rate, various individual stocks, and
stock market indices. However, the initial attempts lacked a clear formal
methodology. Here we present a detailed methodology, using optimization
techniques to build an estimate of the strategy distribution across the
multi-trader population. In contrast to earlier attempts, we are able to
present a systematic method for identifying 'pockets of predictability' in
real-world markets. We find that as each pocket closes up, the black-box system
needs to be 'reset' - which is equivalent to saying that the current
probability estimates of the strategy allocation across the multi-trader
population are no longer accurate. Instead, new probability estimates need to
be obtained by iterative updating, until a new 'pocket of predictability'
emerges and reliable prediction can resume.


title: Revisiting the anomalous rf field penetration into a warm plasma

abstract:
  Radio frequency waves do not penetrate into a plasma and are damped within
it. The electric field of the wave and plasma current are concentrated near the
plasma boundary in a skin layer. Electrons can transport the plasma current
away from the skin layer due to their thermal motion. As a result, the width of
the skin layer increases when electron temperature effects are taken into
account. This phenomenon is called anomalous skin effect. The anomalous
penetration of the rf electric field occurs not only for transversely
propagating to the plasma boundary wave (inductively coupled plasmas) but also
for the wave propagating along the plasma boundary (capacitively coupled
plasmas). Such anomalous penetration of the rf field modifies the structure of
the capacitive sheath. Recent advances in the nonlinear, nonlocal theory of the
capacitive sheath are reported. It is shown that separating the electric field
profile into exponential and non-exponential parts yields an efficient
qualitative and quantitative description of the anomalous skin effect in both
inductively and capacitively coupled plasma.


title: Spectral phase conjugation via extended phase matching

abstract:
  It is shown that the copropagating three-wave-mixing parametric process, with
appropriate type-II extended phase matching and pumped with a short
second-harmonic pulse, can perform spectral phase conjugation and parametric
amplification, which shows a threshold behavior analogous to backward wave
oscillation. The process is also analyzed in the Heisenberg picture, which
predicts a spontaneous parametric down conversion rate in agreement with the
experimental result reported by Kuzucu et al. [Phys. Rev. Lett. 94, 083601
(2005)]. Applications in optical communications, signal processing, and quantum
information processing can be envisaged.


title:
The Geometry of Crashes - A Measure of the Dynamics of Stock Market
  Crises

abstract:
  This paper investigates the dynamics of stocks in the S&P500 index for the
last 30 years. Using a stochastic geometry technique, we investigate the
evolution of the market space and define a new measure for that purpose, which
is a robust index of the dynamics of the market structure and provides
information on the intensity and the sectoral impact of the crises. With this
measure, we analyze the effects of some extreme phenomena on the geometry of
the market. Nine crashes between 1987 and 2001 are compared by looking at the
way they modify the shape of the manifold that describes the S&P500 market
space. These crises are identified as (a) structural, (b) general and (c)
local.


title: Influence of Gravitation on Mass-Energy Equivalence Relation

abstract:
  We study influence of gravitational field on the mass-energy equivalence
relation by incorporating gravitation in the physical situation considered by
Einstein (Ann. Physik, 17, 1905, English translation in ref. [1]) for his first
derivation of mass-energy equivalence. In doing so, we also refine Einstein's
expression (Ann. Physik, 35, 1911, English translation in ref. [3]) for
increase in gravitational mass of the body when it absorbs E amount of
radiation energy.


title:
An efficient numerical quadrature for the calculation of the potential
  energy of wavefunctions expressed in the Daubechies wavelet basis

abstract:
  An efficient numerical quadrature is proposed for the approximate calculation
of the potential energy in the context of pseudo potential electronic structure
calculations with Daubechies wavelet and scaling function basis sets. Our
quadrature is also applicable in the case of adaptive spatial resolution. Our
theoretical error estimates are confirmed by numerical test calculations of the
ground state energy and wave function of the harmonic oscillator in one
dimension with and without adaptive resolution. As a byproduct we derive a
filter, which, upon application on the scaling function coefficients of a
smooth function, renders the approximate grid values of this function. This
also allows for a fast calculation of the charge density from the wave
function.


title: Axisymmetric equilibria with anisotropic resistivity and toroidal flow

abstract:
  The equilibrium of an axisymmetric magnetically confined plasma with
anisotropic resistivity and toroidal flow is investigated in the framework of
magnetohydrodynamics (MHD). The stationary states are determined by an elliptic
differential equation for the poloidal magnetic flux function, a Bernoulli
equation for the pressure and two relations for the resistivity components
parallel and perpendicular to the magnetic field. The equilibrium
characteristics of a tokamak with rectangular cross-section are studied by
means of eigenfunctions in connection with exact solutions for the cases of
"compressible" flows with constant temperature, but varying density on magnetic
surfaces and incompressible ones with constant density, but varying temperature
thereon. Those eigenfunctions can describe either single or multiple toroidal
configurations. In the former case the equilibrium has the following
characteristics: (i) the profiles of the resistivity's components on the
poloidal cross-section are roughly collisional (ii) the electric field
perpendicular to the magnetic surfaces possesses two local extrema within the
plasma and vanishes on the boundary and (iii) the toroidal current density is
peaked close to the magnetic axis and vanishes on the boundary. The impact of
the flow and the aspect ratio on the aforementioned quantities is evaluated for
both "compressible" and incompressible flows.


title:
Spectral shift and Q-change of circular and square-shaped optical
  microcavity modes due to periodic sidewall surface roughness

abstract:
  Radiation loss and resonant frequency shift due to sidewall surface roughness
of circular and square high-contrast microcavities are estimated and compared
by using a boundary integral equations method. An effect of various harmonic
components of the contour perturbation on the Whispering-Gallery (WG) modes in
the circular microdisk and WG-like modes in the square microcavity is
demonstrated. In both cases, contour deformations that are matched to the mode
field pattern cause the most significant frequency detuning and Q-factor
change. Favorably mode-matched deformations have been found, enabling one to
manipulate the Q-factors of the microcavity modes.


title: A Directed Network of Greek and Roman Mythology

abstract:
  We study the Greek and Roman mythology using the network theory. We construct
a directed network by using a dictionary of Greek and Roman mythology in which
the nodes represent the entries listed in the dictionary and we make
directional links from an entry to other entries that appear in its explanatory
part. We find that this network is clearly not a random network but a directed
scale-free network. Also measuring the various quantities which characterize
the mythology network, we analyze the Greek and Roman mythology and compare it
to other real networks.


title: Mesoscale Quantization and Self-Organized Stability

abstract:
  In the world of technology, one of the most important forms of friction is
that of rolling friction. Yet it is one of the least studied of all the known
forms of energy dissipation. In the present experiments we investigate the
oscillatory free-decay of a rigid cube, whose side-length is less than the
diameter of the rigid cylinder on which it rests. The resulting free-decay is
one of harmonic motion with damping. The non-dissipative character of the
oscillation yields to a linear differential equation; however, the damping is
found to involve more than a deterministic nonlinearity. Dominated by rolling
friction, the damping is sensitive to the material properties of the contact
surfaces. For `clean' surfaces of glass on glass, the decay shows features of
mesoscale quantization and self-organized stability.


title: Lienard-Wiechert solution revisited

abstract:
  A self-consistent consideration of the Lienard-Wiechert solition is given
including its heuristic deduction, which involves a future light cone (thus the
lightlike propagation of information from an arbitrarily moving pointlike
charge), and physical interpretation of this field via application of three
distinct reference frames (of an inertial observer, then a non-inertial one
retardedly co-moving with the charged source, and finally, co-moving with the
electromagnetic field). In the last frame the magnetic part of the
Lienard-Wiechert field identically (though not asymptotically) vanishes in all
spacetime together with the Poynting vector. In the second frame, the
properties of energy redistribution and radiation of the field are discussed.
The dynamically caused propagation velocity of the Lienard-Wiechert
electromagnetic field in a vacuum at any final distance from the source is less
than that of light.


title: Dipole radio-frequency power from laser plasmas with no dipole moment

abstract:
  The radio-frequency power radiated from laser-target plasmas in a vacuum can
be orders of magnitude greater than expected from such sources that have a
negligible electric dipole moment. A model combining the Tidman-Stamper circuit
model of a laser-target plasma with the theory of radiation from currents
immersed in plasmas, however, predicts scaling of electric-dipole power
radiated from laser plasmas in agreement with experiments.


title: Effect of cooperative merging on the synchronous flow phase of traffic

abstract:
  Cooperation in merging is introduced by adding interactions between pairs of
vehicles in opposite lanes. Simulations with an improved version of the
modified optimal velocity model are done for two lanes merging into a single
lane. For ~30 seconds prior to reaching the merge region, vehicles in both
lanes adjust their headways to create safe distances in front of and behind the
merging vehicle. Cooperation prevents the transition from free flow to
synchronous flow that occurs for normal merging, provided the merge region is
sufficiently large and the total incoming flow does not exceed the maximum
possible single-lane flow. No long-range vehicle-to-vehicle communication is
required for the type of cooperation considered.


title:
Effect of adaptive cruise control systems on mixed traffic flow near an
  on-ramp

abstract:
  Mixed traffic flow consisting of vehicles equipped with adaptive cruise
control (ACC) and manually driven vehicles is analyzed using car-following
simulations. Unlike simulations that show suppression of jams due to increased
string stability, simulations of merging from an on-ramp onto a freeway have
not thus far demonstrated a substantial positive impact of ACC. In this paper
cooperative merging is proposed to increase throughput and increase distance
traveled in a fixed time (reduce travel times). In such a system an ACC vehicle
senses not only the preceding vehicle in the same lane but also the vehicle
immediately in front in the opposite lane. Prior to reaching the merge region,
the ACC vehicle adjusts its velocity to ensure that a safe gap for merging is
obtained. If on-ramp demand is moderate, partial implementation of cooperative
merging where only main line ACC vehicles react to an on-ramp vehicle is
effective. Significant improvement in throughput (18%) and increases up to 3 km
in distance traveled in 500 s are found for 50% ACC mixed flow relative to the
flow of all manual vehicles. For large demand, full implementation is required
to reduce congestion.


title: White-Light Imaging in a Two Gratings Diffraction Process

abstract:
  A diffractive arrangement that allows imaging of an object without any
intermediate or complementary element is presented. This optical system with
only two diffraction gratings forms color images with white light.


title: Defect modes in one-dimensional photonic lattices

abstract:
  Linear defect modes in one-dimensional photonic lattices are studied
theoretically. For negative (repulsive) defects, various localized defect modes
are found. The strongest confinement of the defect modes appear when the
lattice intensity at the defect site is {\em non-zero} rather than zero. When
launched at small angles into such a defect site of the lattice, a Gaussian
beam can be trapped and undergo snake oscillations under appropriate
conditions.


title:
Measuring the quantum efficiency of single radiating dipoles using a
  scanning mirror

abstract:
  Using scanning probe techniques, we show the controlled manipulation of the
radiation from single dipoles. In one experiment we study the modification of
the fluorescence lifetime of a single molecular dipole in front of a movable
silver mirror. A second experiment demonstrates the changing plasmon spectrum
of a gold nanoparticle in front of a dielectric mirror. Comparison of our data
with theoretical models allows determination of the quantum efficiency of each
radiating dipole.


title: Phase coexistence in a forecasting game

abstract:
  Individual choices are either based on personal experience or on information
provided by peers. The latter case, causes individuals to conform to the
majority in their neighborhood. Such herding behavior may be very efficient in
aggregating disperse private information, thereby revealing the optimal choice.
However if the majority relies on herding, this mechanism may dramatically fail
to aggregate correctly the information, causing the majority adopting the wrong
choice. We address these issues in a simple model of interacting agents who aim
at giving a correct forecast of a public variable, either seeking private
information or resorting to herding. As the fraction of herders increases, the
model features a phase transition beyond which a state where most agents make
the correct forecast coexists with one where most of them are wrong. Simple
strategic considerations suggest that indeed such a system of agents
self-organizes deep in the coexistence region. There, agents tend to agree much
more among themselves than with what they aim at forecasting, as found in
recent empirical studies.

categories: physics.soc-ph cond-mat.dis-nn nlin.AO q-fin.TR


title: Determination of the chemical potential using energy-biased sampling

abstract:
  An energy-biased method to evaluate ensemble averages requiring test-particle
insertion is presented. The method is based on biasing the sampling within the
subdomains of the test-particle configurational space with energies smaller
than a given value freely assigned. These energy-wells are located via unbiased
random insertion over the whole configurational space and are sampled using the
so called Hit&Run algorithm, which uniformly samples compact regions of any
shape immersed in a space of arbitrary dimensions. Because the bias is defined
in terms of the energy landscape it can be exactly corrected to obtain the
unbiased distribution. The test-particle energy distribution is then combined
with the Bennett relation for the evaluation of the chemical potential. We
apply this protocol to a system with relatively small probability of low-energy
test-particle insertion, liquid argon at high density and low temperature, and
show that the energy-biased Bennett method is around five times more efficient
than the standard Bennett method. A similar performance gain is observed in the
reconstruction of the energy distribution.


title: Physmatics

abstract: Public lecture given at The Fields Institute, June 2, 2005.

categories: physics.pop-ph hep-th math.HO physics.hist-ph


title:
Can a few fanatics influence the opinion of a large segment of a
  society?

abstract:
  Models that provide insight into how extreme positions regarding any social
phenomenon may spread in a society or at the global scale are of great current
interest. A realistic model must account for the fact that globalization and
internet have given rise to scale-free networks of interactions between people.
We propose a novel model which takes into account the nature of the
interactions network, and provides some key insights into this phenomenon,
including: (1) There is a fundamental difference between a hierarchical network
whereby people are influenced by those that are higher on the hierarchy but not
by those below them, and a symmetrical network where person-on-person influence
works mutually. (2) A few "fanatics" can influence a large fraction of the
population either temporarily (in the hierarchical networks) or permanently (in
symmetrical networks). Even if the "fanatics" disappear, the population may
still remain susceptible to the positions advocated by them. The model is,
however, general and applicable to any phenomenon for which there is a degree
of enthusiasm or susceptibility to in the population.


title:
A low-cost parallel implementation of direct numerical simulation of
  wall turbulence

abstract:
  A numerical method for the direct numerical simulation of incompressible wall
turbulence in rectangular and cylindrical geometries is presented. The
distinctive feature resides in its design being targeted towards an efficient
distributed-memory parallel computing on commodity hardware. The adopted
discretization is spectral in the two homogeneous directions; fourth-order
accurate, compact finite-difference schemes over a variable-spacing mesh in the
wall-normal direction are key to our parallel implementation. The parallel
algorithm is designed in such a way as to minimize data exchange among the
computing machines, and in particular to avoid taking a global transpose of the
data during the pseudo-spectral evaluation of the non-linear terms. The
computing machines can then be connected to each other through low-cost network
devices. The code is optimized for memory requirements, which can moreover be
subdivided among the computing nodes. The layout of a simple, dedicated and
optimized computing system based on commodity hardware is described. The
performance of the numerical method on this computing system is evaluated and
compared with that of other codes described in the literature, as well as with
that of the same code implementing a commonly employed strategy for the
pseudo-spectral calculation.


title:
Derivation of transformation equations for the parameters that
  characterize a plane acoustic wave without using phase invariance and
  Lorentz-Einstein transformation

abstract:
  We show that the transformation equations for the parameters that
characterize a plane acoustic wave: period, (frequency), wave vector, wave
length and phase velocity can be derived without using phase invariance and
Lorentz-Einstein transformation


title:
Lattice Boltzmann Method with regularized non-equilibrium distribution
  functions

abstract:
  A new lattice Boltzmann (LB) model is introduced, based on a regularization
of the pre-collision distribution functions in terms of the local density,
velocity, and momentum flux tensor. The model dramatically improves the
precision and numerical stability for the simulation of fluid flows by LB
methods. This claim is supported by simulation results of some 2D and 3D flows.


title:
Diffraction of Gaussian beam in a 3D smoothly inhomogeneous media:
  eikonal-based complex geometrical optics approach

abstract:
  The paper presents an ab initio account of the paraxial complex geometrical
optics (CGO) in application to a scalar Gaussian beam propagation and
diffraction in a 3D smoothly inhomogeneous medium. The paraxial CGO deals with
quadratic expansion of the complex eikonal and reduces the wave problem to the
solution of ordinary differential equations of Riccati type. This substantially
simplifies description of Gaussian beams diffraction as compared to full wave
or parabolic (quasi-optics) equations. For a Gaussian beam propagating in a
homogeneous medium or along the symmetry axis in a lens-like medium, the CGO
equations possess analytical solutions, otherwise they can be readily solved
numerically. As a non-trivial example we consider Gaussian beam propagation and
diffraction along a helical ray in an axially symmetric waveguide medium. It is
shown that the major axis of the beam's elliptical cross-section grows
unboundedly; it is oriented predominantly in azimuthal (binormal) direction and
does not obey the parallel transport law.


title:
First principles electron transport: finite-element implementation for
  nanostructures

abstract:
  We have modeled transport properties of nanostructures using the Green's
function method within the framework of the density-functional theory. The
scheme is computationally demanding so that numerical methods have to be chosen
carefully. A typical solution to the numerical burden is to use a special
basis-function set, which is tailored to the problem in question, for example,
the atomic orbital basis. In this paper we present our solution to the problem.
We have used the finite element method (FEM) with a hierarchical high-order
polynomial basis, the so-called p-elements. This method allows the discretation
error to be controlled in a systematic way. The p-elements work so efficiently
that they can be used to solve interesting nanosystems described by non-local
pseudopotentials.
  We demonstrate the potential of the implementation with two different
systems. As a test system a simple Na-atom chain between two leads is modeled
and the results are compared with several previous calculations. Secondly, we
consider a thin hafnium dioxide (HfO2) layer on a silicon surface as a model
for a gate structure of the next generation of microelectronics.


title:
The 4-particle hydrogen-antihydrogen system revisited: twofold
  Hamiltonian symmetry and natural atom antihydrogen

abstract:
  Modern ab initio treatments of H-Hbar systems are inconsistent with the logic
behind algebraic Hamiltonians H(+-)=H(0)+/-deltaH for charge-symmetrical and
charge-asymmetrical 4 unit charge systems like H(2) and HHbar. Since these 2
Hamiltonians are mutually exclusive, only the attractive one can apply for
stable natural molecular H(2). A wrong choice leads to problems with antiatom
Hbar. In line with earlier results on band and line spectra, we now prove that
HL chose the wrong Hamiltonian for H(2). Their theory explains the stability of
attractive system H(2) with a repulsive Hamiltonian instead of with the
attractive one, representative for charge-asymmetrical system HHbar. A new
second order symmetry effect is detected. Repulsive HL Hamiltonian H(+) applies
at long range but at the critical distance, attractive charge-inverted
Hamiltonian H(-)takes over and leads to bond H(2) but in reality, HHbar, for
which we give an analytical proof. Another wrong asymptote choice in the past
also applies for atomic antihydrogen Hbar, which has hidden the Mexican hat
potential for natural hydrogen. This generic solution removes most problems,
physicists and chemists experience with atomic Hbar and molecular HHbar,
including the problem with antimatter in the Universe.


title: Spin-glass-like Dynamics of Social Networks

abstract:
  In this work we study spin-glass (SG) like behavior in the dynamics of
multiple agents in a social or economic context using interactions which are
similar to the physical case. The different preferences shown by individual
agents are represented by orientations of spin-like variables. Because of
limited resources, each agent tries to maximize her total utility function,
giving a prescription for the dynamics of the system similar to the evolution
resulting from the optimization of the interaction of a SG. The coupling
between agents for different attributes may be positive or negative, as in a
physical SG system, forming "frustrations" from the ensuing conflicts, with the
system trying to find an overall equilibrium, but in vain, so that we observe
oscillations. The couplings are provided by matrices corresponding to each
attribute and each agent, which are allowed to have some fixed bias, indicating
the unchangeable component of the make up of the agents from genetic factors or
lasting environmental influences, and also contain a random part from
environmental noise, i.e. the cumulative stochastic effect of lumped factors
not explicitly accounted for in the model.


title: Hurricane Excitation of Earth Eigenmodes

abstract:
  A non-conventional vertical seismometer, with good low-frequency sensitivity,
was used to study earth motions in Macon, Georgia USA during the time of
hurricane Charley, August 2004. During its transitions between water and land,
the powerful storm showed an interesting history of microseisms and also
generated more than half-a-dozen surprisingly coherent oscillations, whose
frequencies ranged from 0.9 to 3 mHz.


title: de Broglie Wave Phase Shifts Induced by Surfaces Closer than 25 nm

abstract:
  Four atom optics experiments that each serve to measure atom-surface
interactions near nanofabricated gratings are presented here. In these
experiments atoms in a beam travel within 25 nm of a material grating bar, and
the analysis incorporates phase shifts for the atomic de Broglie waves due to
interactions betwen Na atoms and silicon nitride surfaces. One atom diffraction
experiment determines the van der Waals coefficient $C_3=2.7\pm$0.8 meVnm$^3$,
and one atom interferometer experiment determines $C_3=4\pm$1 meVnm$^3$. The
results of all four experiments are consistent with the Lifshitz prediction
that is explicitly calculated here for Na-silicon nitride to be $C_3=3.25$
meVnm$^3$. The four atom optics experiments and review of van der Waals theory
are complemented by similar experiments using electron beams and analysis of
image-charge effects.


title:
A note on the solvable model of cosmology in the Earth-related
  coordinate system

abstract:
  As a note for paper [physics/0505035], this is to make it more clear how we
can depend upon Einstein's theory of gravitation and two assumptions of the
cosmological principle and perfect fluid, in the so-called Z-approximation, to
construct a solvable model of cosmology in the Earth-related coordinate system.
Hence, the cosmic acceleration becomes understandable.