title: Deriving the sampling errors of correlograms for general white noise

abstract:
  We derive the second-order sampling properties of certain autocovariance and
autocorrelation estimators for sequences of independent and identically
distributed samples. Specifically, the estimators we consider are the classic
lag windowed correlogram, the correlogram with subtracted sample mean, and the
fixed-length summation correlogram. For each correlogram we derive explicit
formulas for the bias, covariance, mean square error and consistency for
generalised higher-order white noise sequences. In particular, this class of
sequences may have non-zero means, be complexed valued and also includes
non-analytical noise signals. We find that these commonly used correlograms
exhibit lag dependent covariance despite the fact that these processes are
white and hence by definition do not depend on lag.


title: Influence of information flow in the formation of economic cycles

abstract:
  A microscopic approach to macroeconomic features is intended. A model for
macroeconomic behavior based on the Ausloos-Clippe-Pekalski model is built and
investigated. The influence of a discrete time information transfer is
investigated. The formation of economic cycles is observed as a function of the
time of information delay. Three regions of delay time are recognized: short
$t_d \in (2 IS, 4 IS)$ (IS - iteration steps) - the system evolves toward a
unique stable equilibrium state, medium $t_d =5 IS $ or $t_d =6 IS $, the
system undergoes oscillations: stable concentration cycles appear in the
system. For long information flow delay times, $t_d \geq 7$, the systems may
crash for most initial concentrations. However, even in the case of long delay
time the crash time may be long enough to allow observation of the system
evolution and to introduce an appropriate strategy in order to avoid the
collapse of the e.g. company concentration. In the long time delay it is also
possible to observe an "economy resonance" where despite a long delay time the
system evolves for a long time or can even reach a stable state, which insures
its existence.


title: On the exposure to mobile phone radiation in trains

abstract:
  This report presents theoretical estimates of the Power Density levels which
may be reached inside trains. Two possible sources of high levels of radiation
are discussed. The first one arises since the walls of the wagons are metallic
and therefore bounce back almost all radiation impinging on them. The second is
due to the simultaneous emission of a seemingly large number of nearby
telephones. The theoretical study presented here shows that Power Densities
stay at values below reference levels always.


title:
TTRG integration of light transport equations: Azymuthally integrated
  radiances inside a Lambertian foliage

abstract:
  A method for numerically integrating transport equations, combining transfer
matrices, transmission-reflection matrices, and Green's matrices (TTRG), was
recently proposed. The present paper deals specifically with azymuthally
integrated radiances inside a horizontally homogeneous canopy of Lambertian
leaves. Its main purpose is to test the accuracy of TTRG by applying it to
non-trivial models possessing analytical solutions, that were given in another
paper. Comparison is made with the widely used iterative integration (or
'relaxation' method). Cases of extreme light trapping are given for which
iterative integration is hardly practical, while TTRG remains as accurate and
rapid.


title: Multi-verses, Micro-universes and Elementary Particles (Hadrons)

abstract:
  We present here a panoramic view of our unified, bi-scale theory of
gravitational and strong interactions [which is mathematically analogous to the
last version of N.Rosen's bi-metric theory, and yields physical results similar
to strong gravity's]. This theory, developed during the last 25 years, is
purely geometrical in nature, adopting the methods of general relativity for
the description of hadron structure and strong interactions. In particular,
hadrons can be associated with "strong black-holes", from the external point of
view, and with micro-universes, from the internal point of view. Among the
results presented in this extended summary, let us mention the elementary
derivation: (i) of confinement and (ii) asymptotic freedom for the hadron
constituents; (iii) of the Yukawa behaviour for the strong potential at the
static limit; (iv) of the strong coupling "constant", and (v) of mesonic mass
spectra. Incidentally, within the present approach, results obtained for
hadrons can yield information about the corresponding multi-verses, and
viceversa.


title: Plasma dynamics and a significant error of macroscopic averaging

abstract:
  The methods of macroscopic averaging used to derive the macroscopic Maxwell
equations from electron theory are methodologically incorrect and lead in some
cases to a substantial error. For instance, these methods do not take into
account the existence of a macroscopic electromagnetic field EB, HB generated
by carriers of electric charge moving in a thin layer adjacent to the boundary
of the physical region containing these carriers. If this boundary is
impenetrable for charged particles, then in its immediate vicinity all carriers
are accelerated towards the inside of the region. The existence of the
privileged direction of acceleration results in the generation of the
macroscopic field EB, HB. The contributions to this field from individual
accelerated particles are described with a sufficient accuracy by the
Lienard-Wiechert formulas. In some cases the intensity of the field EB, HB is
significant not only for deuteron plasma prepared for a controlled
thermonuclear fusion reaction but also for electron plasma in conductors at
room temperatures. The corrected procedures of macroscopic averaging will
induce some changes in the present form of plasma dynamics equations. The
modified equations will help to design improved systems of plasma confinement.


title:
First results from a Liquid Argon Time Projection Chamber in a Magnetic
  Field

abstract:
  A small liquid argon Time Projection Chamber (LAr TPC) was operated for the
first time in a magnetic field of 0.55 Tesla. The imaging properties of the
detector were not affected by the magnetic field. In a test run with cosmic
rays a sample of through going and stopping muons was collected. The chamber
with the readout electronics and the experimental setup are described. A few
selected events were reconstructed and analyzed and the results are presented.
The magnetic bending of the charged particle tracks allows the determination of
the electric charge and the momentum, even for particles not fully contained in
the drift chamber. These features are e.g. required for future neutrino
detectors at a neutrino factory.


title: AOPDF-shaped optical parametric amplifier output in the visible

abstract:
  Time Shaping of ultrashort visible pulses has been performed using a
specially designed Acousto-Optic Programmable Dispersive Filter of 50%
efficiency at the output of a two-stage noncollinear optical parametric
amplifier. The set-up is compact and reliable. It provides a tunable shaped
source in the visible with unique features: 4 ps shaping window with preserved
tunability over 500-650 nm, and pulses as short as 30 fs. Several $\mu$J output
energy is easily obtained.


title: Nonspreading Light Pulses in Photonic Crystals

abstract:
  We investigate propagation of light pulses in photonic crystals in the
vicinity of the zero-diffraction point. We show that Gaussian pulses due to
nonzero width of their spectrum spread weakly in space and time during the
propagation. We also find the family of nonspreading pulses, propagating
invariantly in the vicinity of the zero diffraction point of photonic crystals.


title: Statistical model for intermittent plasma edge turbulence

abstract:
  The Probability Distribution Function of plasma density fluctuations at the
edge of fusion devices is known to be skewed and strongly non-Gaussian. The
causes of this peculiar behaviour are, up to now, largely unexplored. On the
other hand, understanding the origin and the properties of edge turbulence is a
key issue in magnetic fusion research. In this work we show that a stochastic
fragmentation model, already successfully applied to fluid turbulence, is able
to predict an asymmetric distribution that closely matches experimental data.
The asymmetry is found to be a direct consequence of intermittency. A
discussion of our results in terms of recently suggested BHP universal curve
[S.T. Bramwell, P.C.W. Holdsworth, J.-F. Pinton, Nature (London) 396, 552
(1998)], that should hold for strongly correlated and critical systems, is also
proposed


title:
Explicit predictability and dispersion scaling exponents in fully
  developed turbulence

abstract:
  We apply a simple method to provide explicit expressions for different
scaling exponents in intermittent fully developed turbulence, that before were
only given through a Legendre transform. This includes predictability exponents
for infinitesimal and non infinitesimal perturbations, Lagrangian velocity
exponents, and dispersion exponents. We obtain also new results concerning
inverse statistics corresponding to exit-time moments.


title: Brownian Motion Captured with a Self-Mixing Laser

abstract:
  We measured the overall motion of Brownian particles suspended in water by a
self-mixing thin-slice solid-state laser with extreme optical sensitivity. From
the demodulated signal of laser intensity fluctuations through self-mixing
modulations by the interference between the lasing field and Doppler-shifted
scattered fields from Brownian particles, it was found that the changes over
time in random walks of small particles suspended in water result in different
overall dynamics when the field of vision for particles seen by the laser beam
(scale of the observation) is changed. At a small focal volume of the laser
beam, in which the relevant diffusion broadening is observed, the overall
motion which can be represented by the motion of a ''virtual'' single particle
whose velocity obeys a double-peaked non-Gaussian distribution function. The
fast motion of a virtual particle, featuring fractional Brownian motion, which
leads to a pure random walk with increasing the observation time, has been
characterized in terms of mean-square displacements of a virtual particle.


title: Economic exchanges in a stratified society: End of the middle class?

abstract:
  We study the effect of the social stratification on the wealth distribution
on a system of interacting economic agents that are constrained to interact
only within their own economic class. The economical mobility of the agents is
related to its success in exchange transactions. Different wealth distributions
are obtained as a function of the width of the economic class. We find a range
of widths in which the society is divided in two classes separated by a deep
gap that prevents further exchange between poor and rich agents. As a
consequence, the middle wealth class is eliminated. The high values of the Gini
indices obtained in these cases indicate a highly unequal society. On the other
hand, lower and higher widths induce lower Gini indices and a fairer wealth
distribution.


title: Surviving opinions in Sznajd models on complex networks

abstract:
  The Sznajd model has been largely applied to simulate many sociophysical
phenomena. In this paper we applied the Sznajd model with more than two
opinions on three different network topologies and observed the evolution of
surviving opinions after many interactions among the nodes. As result, we
obtained a scaling law which depends of the network size and the number of
possible opinions. We also observed that this scaling law is not the same for
all network topologies, being quite similar between scale-free networks and
Sznajd networks but different for random networks.


title:
Dynamical Effects Due to Fringe Field of the Magnet in Circular
  Accelerators

abstract:
  The leading Lie generators, including the chromatic effects, due to hard-edge
fringe field of single multipole and solenoid are derived from the vector
potentials within a Hamiltonian system. These nonlinear generators are applied
to the interaction region of PEP-II to analyze the linear errors due to the
feed-down from the off-centered quadrupoles and solenoid. The nonlinear effects
of tune shifts at large amplitude, the synchro-betatron sidebands near half
integer and their impacts on the dynamic aperture are studied in the paper.


title:
Observation of atom wave phase shifts induced by van der Waals
  atom-surface interactions

abstract:
  The development of nanotechnology and atom optics relies on understanding how
atoms behave and interact with their environment. Isolated atoms can exhibit
wave-like (coherent) behaviour with a corresponding de Broglie wavelength and
phase which can be affected by nearby surfaces. Here an atom interferometer is
used to measure the phase shift of Na atom waves induced by the walls of a 50
nm wide cavity. To our knowledge this is the first direct measurement of the de
Broglie wave phase shift caused by atom-surface interactions. The magnitude of
the phase shift is in agreement with that predicted by quantum electrodynamics
for a non-retarded van der Waals interaction. This experiment also demonstrates
that atom-waves can retain their coherence even when atom-surface distances are
as small as 10 nm.


title:
Calculation of single-beam two-photon absorption rate of lanthanides:
  effective operator method and perturbative expansion

abstract:
  Perturbative contributions to single-beam two-photon transition rates may be
divided into two types. The first, involving low-energy intermediate states,
require a high-order perturbation treatment, or an exact diagonalization. The
other, involving high energy intermediate states, only require a low-order
perturbation treatment. We show how to partition the effective transition
operator into two terms, corresponding to these two types, in such a way that a
many-body perturbation expansion may be generated that obeys the linked cluster
theorem and has a simple diagrammatic representation.


title:
Calculation of single-beam two-photon absorption transition rate of
  rare-earth ions using effective operator and diagrammatic representation

abstract:
  Effective operators needed in single-beam two-photon transition calculations
have been represented with modified Goldstone diagrams similar to the type
suggested by Duan and co-workers [J. Chem. Phys. 121, 5071 (2004) ]. The rules
to evaluate these diagrams are different from those for effective Hamiltonian
and one-photon transition operators. It is verified that the perturbation terms
considered contain only connected diagrams and the evaluation rules are
simplified and given explicitly.


title:
Conservation of connectivity of model-space effective interactions under
  a class of similarity transformation

abstract:
  Effective interaction operators usually act on a restricted model space and
give the same energies (for Hamiltonian) and matrix elements (for transition
operators etc.) as those of the original operators between the corresponding
true eigenstates. Various types of effective operators are possible. Those well
defined effective operators have been shown being related to each other by
similarity transformation. Some of the effective operators have been shown to
have connected-diagram expansions. It is shown in this paper that under a class
of very general similarity transformations, the connectivity is conserved. The
similarity transformation between hermitian and non-hermitian
Rayleigh-Schr\"{o}dinger perturbative effective operators is one of such
transformation and hence the connectivity can be deducted from each other.


title:
Spiral Vortices and Taylor Vortices in the Annulus between Rotating
  Cylinders and the Effect of an Axial Flow

abstract:
  We present numerical simulations of vortices that appear via primary
bifurcations out of the unstructured circular Couette flow in the
Taylor-Couette system with counter-rotating as well as with co-rotating
cylinders. The full, time dependent Navier-Stokes equations are solved with a
combination of a finite difference and a Galerkin method for a fixed axial
periodicity length of the vortex patterns and for a finite system of aspect
ratio 12 with rigid nonrotating ends in a setup with radius ratio eta=0.5.
Differences in structure, dynamics, symmetry properties, bifurcation and
stability behavior between spiral vortices with azimuthal wave numbers M=+-1
and M=0 Taylor vortices are elucidated and compared in quantitative detail.
Simulations in axially periodic systems and in finite systems with stationary
rigid ends are compared with experimental spiral data. In a second part of the
paper we determine how the above listed properties of the M=-1,0,1 vortex
structures are changed by an externally imposed axial through-flow with
Reynolds numbers in the range -40 <= Re <= 40. Among others we investigate when
left handed or right handed spirals or toroidally closed vortices are
preferred.


title: Thermal emission by photonic micro-textured surfaces

abstract:
  Ordinary metallic photonic crystals (PCs) have photonic band gaps in which
the density of states (DOS) is strongly modified. Thermal emission of photons
can be suppressed and enhanced accordingly. We consider the thermal emission
characteristics of a metallic photonic crystal slab with a tunable thickness
which in the thick limit approaches that of a photonic crystal and in the thin
limit approaches that of a textured surface. We find that a thick photonic
crystal suppresses emission in a specific range while a thin slab suppresses
low frequency emission.


title:
Dependence of spontaneous emission rates of emitters on the refractive
  index of the surrounding medial

abstract:
  For emitters in a medium, different macroscopic or microscopic theoretical
models predict substantially different dependencies of the spontaneous emission
lifetime on refractive index. Various measurements have been carried out on
Eu$^{3+}$, Ce$^{3+}$ and Nd$^{3+}$ ions, and quantum dots in different
surrounding medial. The dependence of the spontaneous emission rates on
refractive index has been interpreted with different models. By closely
examining some of the experimental results, we notice that some interpretations
are based on implicit assumptions which are hard to justify, and some
measurements contain too big uncertainties to discriminate among different
models. In this work we reanalyse the avilable measured results and give a
consistent interpretation.


title:
Bessel beam through a dielectric slab at oblique incidence: the case of
  total reflection

abstract:
  The oblique incidence of a Bessel beam on a dielectric slab with refractive
index n1 surrounded by a medium of a refractive index n>n1 may be studied
simply by expanding the Bessel beam into a set of plane waves forming the same
angle with the axis of the beam. In the present paper we examine a Bessel beam
that impinges at oblique incidence onto a layer in such a way that each
plane-wave component impinges with an angle larger than the critical angle.


title: Mammographic image restoration using maximum entropy deconvolution

abstract:
  An image restoration approach based on a Bayesian maximum entropy method
(MEM) has been applied to a radiological image deconvolution problem, that of
reduction of geometric blurring in magnification mammography. The aim of the
work is to demonstrate an improvement in image spatial resolution in realistic
noisy radiological images with no associated penalty in terms of reduction in
the signal-to-noise ratio perceived by the observer. Images of the TORMAM
mammographic image quality phantom were recorded using the standard
magnification settings of 1.8 magnification/fine focus and also at 1.8
magnification/broad focus and 3.0 magnification/fine focus; the latter two
arrangements would normally give rise to unacceptable geometric blurring.
Measured point-spread functions were used in conjunction with the MEM image
processing to de-blur these images. The results are presented as comparative
images of phantom test features and as observer scores for the raw and
processed images. Visualization of high resolution features and the total image
scores for the test phantom were improved by the application of the MEM
processing. It is argued that this successful demonstration of image
de-blurring in noisy radiological images offers the possibility of weakening
the link between focal spot size and geometric blurring in radiology, thus
opening up new approaches to system optimization.


title: A network-based ranking system for American college football

abstract:
  American college football faces a conflict created by the desire to stage
national championship games between the best teams of a season when there is no
conventional playoff system to decide which those teams are. Instead, ranking
of teams is based on their record of wins and losses during the season, but
each team plays only a small fraction of eligible opponents, making the system
underdetermined or contradictory or both. It is an interesting challenge to
create a ranking system that at once is mathematically well-founded, gives
results in general accord with received wisdom concerning the relative
strengths of the teams, and is based upon intuitive principles, allowing it to
be accepted readily by fans and experts alike. Here we introduce a
one-parameter ranking method that satisfies all of these requirements and is
based on a network representation of college football schedules.


title: Recurrence analysis of the NASDAQ crash of April 2000

abstract:
  Recurrence Plot (RP) and Recurrence Quantification Analysis RQA) are signal
numerical analysis methodologies able to work with non linear dynamical systems
and non stationarity. Moreover they well evidence changes in the states of a
dynamical system. It is shown that RP and RQA detect the critical regime in
financial indices (in analogy with phase transition) before a bubble bursts,
whence allowing to estimate the bubble initial time. The analysis is made on
NASDAQ daily closing price between Jan. 1998 and Nov. 2003. The NASDAQ bubble
initial time has been estimated to be on Oct. 19, 1999.


title:
A Test Facility for the International Linear Collider at SLAC End
  Station A, for Prototypes of Beam Delivery and IR Components

abstract:
  The SLAC Linac can deliver damped bunches with ILC parameters for bunch
charge and bunch length to End Station A. A 10Hz beam at 28.5 GeV energy can be
delivered there, parasitic with PEP-II operation. We plan to use this facility
to test prototype components of the Beam Delivery System and Interaction
Region. We discuss our plans for this ILC Test Facility and preparations for
carrying out experiments related to collimator wakefields and energy
spectrometers. We also plan an interaction region mockup to investigate effects
from backgrounds and beam-induced electromagnetic interference.


title: Aristotle and Gautama on Logic and Physics

abstract:
  The question of the origins of logic as a formal discipline is of special
interest to the historian of physics since it represents a turning inward to
examine the very nature of reasoning and the relationship between thought and
reality. In the West, Aristotle (384-322 BCE) is generally credited with the
formalization of the tradition of logic and also with the development of early
physics. In India, the Rigveda itself in the hymn 10.129 suggests the
beginnings of the representation of reality in terms of various logical
divisions that were later represented formally as the four circles of: "A",
"not A", ":A and not A", and "not A and not not A''. According to Puranic
accounts, Medhatithi Gautama and Aksapada Gautama (or Gotama), which are
perhaps two variant names for the author of the early formal text on Indian
logic, belonged to about 550 BCE. The Greek and the Indian traditions seem to
provide the earliest formal representations of logic, and in this article we
ask if they influenced each other. We are also interested in the scope of early
logic, since this gives an idea to us of the way early thinkers thought about
nature and change. We will show that Greek and Indian logical traditions have
much that is distinctive and unique and that they must have emerged
independently.


title: Empirical study and model of personal income

abstract:
  Personal income distributions in Japan are analyzed empirically and a simple
stochastic model of the income process is proposed. Based on empirical facts,
we propose a minimal two-factor model. Our model of personal income consists of
an asset accumulation process and a wage process. We show that these simple
processes can successfully reproduce the empirical distribution of income. In
particular, the model can reproduce the particular transition of the
distribution shape from the middle part to the tail part. This model also
allows us to derive the tail exponent of the distribution analytically.


title:
Reconstruction of an object from its symmetry-averaged diffraction
  pattern

abstract:
  By suitably generalizing the Fourier constraint projection in the difference
map phasing algorithm, an object can be reconstructed from its diffraction
pattern even when the latter has been incoherently averaged over a discrete
group of symmetries. This resolves an ambiguity in the recent proposal for
aligning molecules by means of their anisotropic dielectric interaction with an
intense light field. The algorithm is demonstrated with simulated data in two
and three dimensions.


title: A Fundamental Scale for Acceleration from the Holographic Principle

abstract:
  From the Eddington-Weinberg relationship, which may be explained by the
holographic principle and the cosmic coincidence in a flat Universe, it follows
that the characteristic gravitational acceleration aN associated with the
nucleon and its Compton wavelength is of order the Hubble acceleration H0c in
this epoch. A natural scaling for the cosmological constant is obtained from
this acceleration term. It also happens that the critical acceleration a0
associated with the MOND theory is of order aN.


title: Interrelation of work function and surface stability: the case of BaAl4

abstract:
  The relationship between the work function (Phi) and the surface stability of
compounds is, to our knowledge, unknown, but very important for applications
such as organic light-emitting diodes. This relation is studied using
first-principles calculations on various surfaces of BaAl4. The most stable
surface [Ba terminated (001)] has the lowest Phi (1.95 eV), which is lower than
that of any elemental metal including Ba. Adding barium to this surface neither
increases its stability nor lowers its work function. BaAl4 is also strongly
bound. These results run counter to the common perception that stability and a
low Phi are incompatible. Furthermore, a large anisotropy and a stable
low-work-function surface are predicted for intermetallic compounds with polar
surfaces.


title:
Photoemission Electron Microscopy as a tool for the investigation of
  optical near fields

abstract:
  Photoemission electron microscopy was used to image the electrons
photoemitted from specially tailored Ag nanoparticles deposited on a Si
substrate (with its native oxide SiO$_{x}$). Photoemission was induced by
illumination with a Hg UV-lamp (photon energy cutoff $\hbar\omega_{UV}=5.0$ eV,
wavelength $\lambda_{UV}=250$ nm) and with a Ti:Sapphire femtosecond laser
($\hbar\omega_{l}=3.1$ eV, $\lambda_{l}=400$ nm, pulse width below 200 fs),
respectively. While homogeneous photoelectron emission from the metal is
observed upon illumination at energies above the silver plasmon frequency, at
lower photon energies the emission is localized at tips of the structure. This
is interpreted as a signature of the local electrical field therefore providing
a tool to map the optical near field with the resolution of emission electron
microscopy.


title:
Design in Complex Systems: Individual Performance versus System
  Efficiency

abstract:
  This paper studies the correlations of the average winnings of agents and the
volatilities of systems based on mix-game model which is an extension of
minority game (MG). In mix-game, there are two groups of agents; group1 plays
the majority game, but the group2 plays the minority game. The results show
that the correlations between the average winnings of agents and the mean of
local volatilities are different with different combinations of agents' memory
lengths when the proportion of agents in group1 increases. The average winnings
of agents can represent the average individual performance and the volatility
of a system can represent the efficiency of the system. Therefore, these
results imply that the combinations of agents' memory lengths largely influence
the relation between the system efficiency and the average individual
performance. These results could give some guidance in designing complex
systems.


title:
An equation-free computational approach for extracting population-level
  behavior from individual-based models of biological dispersal

abstract:
  The movement of many organisms can be described as a random walk at either or
both the individual and population level. The rules for this random walk are
based on complex biological processes and it may be difficult to develop a
tractable, quantitatively-accurate, individual-level model. However, important
problems in areas ranging from ecology to medicine involve large collections of
individuals, and a further intellectual challenge is to model population-level
behavior based on a detailed individual-level model. Because of the large
number of interacting individuals and because the individual-level model is
complex, classical direct Monte Carlo simulations can be very slow, and often
of little practical use. In this case, an equation-free approach may provide
effective methods for the analysis and simulation of individual-based models.
In this paper we analyze equation-free coarse projective integration. For
analytical purposes, we start with known partial differential equations
describing biological random walks and we study the projective integration of
these equations. In particular, we illustrate how to accelerate explicit
numerical methods for solving these equations. Then we present illustrative
kinetic Monte Carlo simulations of these random walks and show a decrease in
computational time by as much as a factor of a thousand can be obtained by
exploiting the ideas developed by analysis of the closed form PDEs. The
illustrative biological example here is chemotaxis, but it could be any random
walker which biases its movement in response to environmental cues.


title: Predictability of Shanghai Stock Market by Agent-based Mix-game Model

abstract:
  This paper reports the effort of using agent-based mix-game model to predict
financial time series. It introduces simple generic algorithm into the
prediction methodology, and gives an example of its application to forecasting
Shanghai Index. The results show that this prediction methodology is effective
and agent-based mix-game model is a potential good model to predict time series
of financial markets


title: On the origin of quantum mechanics

abstract:
  Action at distance in Newtonian physics is replaced by finite propagation
speeds in classical post--Newtonian physics. As a result, the differential
equations of motion in Newtonian physics are replaced by functional
differential equations, where the delay associated with the finite propagation
speed is taken into account. Newtonian equations of motion, with
post--Newtonian corrections, are often used to approximate the functional
differential equations. Are the finite propagation speeds the origin of the
quantum mechanics? In this work a simple atomic model based on a functional
differential equation which reproduces the quantized Bohr atomic model is
presented. As straightforward application of the result the fine structure of
the hydrogen atom is approached.


title:
Comment on the use of the method of images for calculating
  electromagnetic responses of interacting spheres

abstract:
  In this Comment I argue that the method of images used by Huang, Yu, Gu and
co-authors [Phys Rev. E, 65, 21401 (2002); Phys Rev. E., 69, 51402 (2004)] to
calculate electromagnetic properties of interacting spheres at finite
frequencies is inapplicable and does not provide a physically meaningful
approximation.


title: Shell to shell energy transfer in MHD, Part I: steady state turbulence

abstract:
  We investigate the transfer of energy from large scales to small scales in
fully developed forced three-dimensional MHD-turbulence by analyzing the
results of direct numerical simulations in the absence of an externally imposed
uniform magnetic field. Our results show that the transfer of kinetic energy
from the large scales to kinetic energy at smaller scales, and the transfer of
magnetic energy from the large scales to magnetic energy at smaller scales, are
local, as is also found in the case of neutral fluids, and in a way that is
compatible with Kolmogorov (1941) theory of turbulence. However, the transfer
of energy from the velocity field to the magnetic field is a highly non-local
process in Fourier space. Energy from the velocity field at large scales can be
transfered directly into small scale magnetic fields without the participation
of intermediate scales. Some implications of our results to MHD turbulence
modeling are also discussed.


title:
A simple method for obtaining electron scattering phase shifts from
  energies of an atom in a cavity

abstract:
  We present a simple method for obtaining elastic scattering phase shifts and
cross sections from energies of atoms or ions in cavities. This method does not
require calculations of wavefunctions of continuum states, is very general, and
is extremely convenient from practical point of view: some conventional
computer codes designed for the energies of bound states can be used without
modifications. The application of the method is illustrated on an example of
electron scattering from Kr and Ar. From Brueckner orbital energies in variable
cavities, we have obtained ab initio cross sections that are in close agreement
with experiment. The relativistic effects are also considered and found to be
small below 10 eV.


title: Electron dynamics in strong laser pulse illumination

abstract:
  We analyze the dynamics of up to $10^5$ electrons resulting from illuminating
a Xenon cluster with 9093 atoms with intense laser pulses of different length
and peak intensity. Interesting details of electron motion are identified which
can be probed with a time resolution of 100 attoseconds. Corresponding
experiments would shed light on unexplored territory in complex electronic
systems such as clusters and they would also permit to critically access the
present theoretical description of this dynamics.


title:
Divergence of Dipole Sums and the Nature of Non-Lorentzian Exponentially
  Narrow Resonances in One-Dimensional Periodic Arrays of Nanospheres

abstract:
  Origin and properties of non-Lorentzian spectral lines in linear chains of
nanospheres are discussed. The lines are shown to be super-exponentially narrow
with the characteristic width proportional to exp[-C(h/a)^3] where C is a
numerical constant, h the spacing between the nanospheres in the chain and a
the sphere radius. The fine structure of these spectral lines is also
investigated.


title:
Statistical description of short pulses in long optical fibers: Effects
  of nonlocality

abstract:
  We present a statistical description of the propagation of short pulses in
long optical fibers, taking into account the Kerr and nonlocal nonlinearities
on an equal footing. We use the Wigner approach on the modified nonlinear
Schroedinger equation to obtain a wave kinetic equation and a nonlinear
dispersion relation. The latter exhibit that the optical pulse decoherence
reduces the growth rate of the modulational instability, and thereby contribute
to the nonlinear stability of the pulses in long optical fibers. It is also
found that the interaction between spectral broadening and nonlocality tends to
extend the instability region.


title:
Comment on "Silver nanoparticle array structures that produce remarkably
  narrow plasmon lineshapes" [J. Chem. Phys. 120, 10871 (2004)]

abstract:
  In this Comment I discuss two incorrect statements which were made in the
paper "Silver nanoparticle array structures that produce remarkably narrow
plasmon line shapes" [J. Chem. Phys.120, 10871 (2004)] by Zou, Janel, and
Schatz (ZJS). The first statement is about the use of quasistatic approximation
in my earlier work on the similar subject, and the second statement concerns
the possibility of exact cancellation of radiative relaxation in periodical
chains of nanoparticles. The relationship between the quasistatic
approximation, the dipole approximation, and the approximation due to Doyle
[Phys. Rev. B39, 9852 (1989)] which was used by ZJS is clarified. It is shown
that the exact cancellation of radiative relaxation cannot take place in the
particular geometry considered by ZJS.


title: Shell to shell energy transfer in MHD, Part II: Kinematic dynamo

abstract:
  We study the transfer of energy between different scales for forced
three-dimensional MHD turbulent flows in the kinematic dynamo regime. Two
different forces are examined: a non-helical Taylor Green flow with magnetic
Prandtl number P_M=0.4, and a helical ABC flow with P_M=1. This analysis allows
us to examine which scales of the velocity flow are responsible for dynamo
action, and identify which scales of the magnetic field receive energy directly
from the velocity field and which scales receive magnetic energy through the
cascade of the magnetic field from large to small scales. Our results show that
the turbulent velocity fluctuations are responsible for the magnetic field
amplification in the small scales (small scale dynamo) while the large scale
field is amplified mostly due to the large scale flow. A direct cascade of the
magnetic field energy from large to small scales is also present and is a
complementary mechanism for the increase of the magnetic field in the small
scales. Input of energy from the velocity field in the small magnetic scales
dominates over the energy that is cascaded down from the large scales until the
large-scale peak of the magnetic energy spectrum is reached. At even smaller
scales, most of the magnetic energy input is from the cascading process.


title: Substance-like physical quantities in special relativity

abstract:
  Handling substance-like physical quantities in the limits of special
relativity theory we should make a net distinction between those which present
a proper (rest) magnitude and those which have not. We show how the theory
relates them via relativistic transformation equations.


title: Filament attachment dynamics in actin-based propulsion

abstract:
  Theory and experiment have established that F-actin filaments are strongly
attached to the intracellular parasites (such as Listeria) they propel with
``comet tails''. We consider the implications of these observations for
propulsion. By calculating the motion produced in various models of attachment
and comparing to experiment we demonstrate that the attachment must be sliding
rather than hinged. By modeling experiments on ActA-coated spheres we draw
conclusions regarding the interaction between F-actin and their surfaces that
may also be applicable to living systems.


title: Low magnetic Prandtl number dynamos with helical forcing

abstract:
  We present direct numerical simulations of dynamo action in a forced Roberts
flow. The behavior of the dynamo is followed as the mechanical Reynolds number
is increased, starting from the laminar case until a turbulent regime is
reached. The critical magnetic Reynolds for dynamo action is found, and in the
turbulent flow it is observed to be nearly independent on the magnetic Prandtl
number in the range from 0.3 to 0.1. Also the dependence of this threshold with
the amount of mechanical helicity in the flow is studied. For the different
regimes found, the configuration of the magnetic and velocity fields in the
saturated steady state are discussed.


title: Advantages of adopting the operational definition of weight

abstract:
  With rare exceptions, in high school and college/university physics courses
literature and in journals of physics, the weight is defined as a gravitational
force or an exclusive consequence of it. These definitions lack logic from the
perspective of present knowledge and can be misleading. The operational
definition of weight of a body as the force the body exerts on its support or
suspender can eliminate the ambiguities associated to "true weight", "apparent
weight", "state of weightlessness", "zero weight", "zero gravity",
"microgravity", "vertical", "up" and "down". Nevertheless, the concept of
weight of a body is not fundamental in Physics and its exclusion from the
physics vocabulary will eliminate some of former concepts or their
ambiguousness with evident benefit for physics teaching and learning. This
paper discusses weight of a body concepts and presents several examples that
show the advantages of avoiding its use or adopting the above-mentioned
operational definition. It is believed that this will eliminates the frequent
identification with the body's mass and will boost student's understanding
associated subjects.


title:
Gravity as the Second-Order Relativistic-Manifestation of
  Electrostatic-Force

abstract:
  It is well known that magnetic force between two current carrying conductors
is a relativistic manifestation of net electrostatic force between relatively
moving electrons & protons of the two wires. On similar grounds but with more
accurate considerations i.e., of second order relativistic considerations, it
is shown here that gravitational-force between two bodies is in-fact due to
relativistic manifestation of net electrostatic force between protons &
revolving electrons in atoms of the two bodies. As special-relativity provides
a bridge between electricity and magnetism, in somewhat similar way (as
described in the paper) it is shown that once again it is the
special-relativity which provides the much sought-after link between
electrostatic force and gravitational force. If magnetism is the first-order
(velocity-dependant) effect of moving electrons in conductor, gravitation is
the second-order (acceleration-dependant) effect of revolving electrons in
atoms. The new proposed gravitation-theory seems to be well in accordance with
gravity behavior i.e., it correctly predicts that gravity is a long-range
attractive-force proportional to masses & follows inverse-square-law and is
transmitted with the velocity of light.


title:
How do clarinet players adjust the resonances of their vocal tracts for
  different playing effects

abstract:
  In a simple model, the reed of the clarinet is mechanically loaded by the
series combination of the acoustical impedances of the instrument itself and of
the player's vocal tract. Here we measure the complex impedance spectrum of
players' tracts using an impedance head adapted to fit inside a clarinet
mouthpiece. A direct current shunt with high acoustical resistance allows
players to blow normally, so the players can simulate the tract condition under
playing conditions. The reproducibility of the results suggest that the
players' "muscle memory" is reliable for this task. Most players use a single,
highly stable vocal tract configuration over most of the playing range, except
for the altissimo register. However, this 'normal' configuration varies
substantially among musicians. All musicians change the configuration, often
drastically for "special effects'' such as glissandi and slurs: the tongue is
lowered and the impedance magnitude reduced when the player intends to lower
the pitch or to slur downwards, and vice versa.


title:
Multiple Projection Optical Diffusion Tomography with Plane Wave
  Illumination

abstract:
  We describe a new data collection scheme for optical diffusion tomography in
which plane wave illumination is combined with multiple projections in the slab
imaging geometry. Multiple projection measurements are performed by rotating
the slab around the sample. The advantage of the proposed method is that the
measured data can be much more easily fitted into the dynamic range of most
commonly used detectors. At the same time, multiple projections improve image
quality by mutually interchanging the depth and transverse directions, and the
scanned (detection) and integrated (illumination) surfaces. Inversion methods
are derived for image reconstructions with extremely large data sets. Numerical
simulations are performed for fixed and rotated slabs.


title: Theoretical model for the evolution of the linguistic diversity

abstract:
  Here we describe how some important scaling laws observed in the distribution
of languages on Earth can emerge from a simple computer simulation. The
proposed language dynamics includes processes of selective geographic
colonization, linguistic anomalous diffusion and mutation, and interaction
among populations that occupy different regions. It is found that the
dependence of the linguistic diversity on the area after colonization displays
two power law regimes, both described by critical exponents which are dependent
on the mutation probability. Most importantly for the future prospect of
world's population, our results show that the linguistic diversity always
decrease to an asymptotic very small value if large areas and sufficiently long
times of interaction among populations are considered.


title: Surface-mode microcavity

abstract:
  Optical microcavities based on zero-group-velocity surface modes in photonic
crystal slabs are studied. It is shown that high quality factors can be easily
obtained for such microcavities in photonic crystal slabs. With increasing of
the cavity length, the quality factor is gradually enhanced and the resonant
frequency converges to that of the zero-group-velocity surface mode in the
photonic crystal. The number of the resonant modes with high quality factors is
mainly determined by the number of surface modes with zero-group velocity.


title:
Experimental observations of a new information channal in nature with
  aim of quartz resonators system

abstract:
  The results of long-term (two-year) experimental observations of frequencies
of two quartz resonators, one of which is placed in special magnetic system
that creates vector potential field, another (calibration one) is placed
outside this system, have been presented. Changes with different periodicity:
24 h, high-definite 7 days complex-form period, 27 days and year periods were
detected during the observation of differences of these quartz resonators
frequencies. The tangents which have been drawn to a terrestrial parallel at
the moment of near-daily observation of measured quantity minima form the
basic, most powerful subset of directions of tangents having a sharp corner
with dipole component of vector potential of the Sun' magnetic field in a range
from $50^\circ$ up to $80^\circ$ at annual rotation of laboratory around the
Sun together with the Earth. Also there are three subsets of directions
similarly drawn tangents fixed in physical space that coincide with similar
subsets of tangents directions drawn in the same way to points of radioactive
elements $\beta$-decay count rate minimum under the long $\beta$-decay research
during daily and annual rotation of laboratory together with the Earth. It is
necessary to point out that the form of the curves of quartzes frequencies
difference changes in scales of the 7-day's period with reliability coincides
next year, and observable minima of frequencies in co-phase points of space
coincide to within several tens minutes. It is shown that the amplitude of the
signal was $5\div10$ times lesser in the period from 20-th, July, till 20-th,
January, than from 20-th, January, till 20-th, July.


title:
A New Technique for Finding Needles in Haystacks: A Geometric Approach
  to Distinguishing Between a New Source and Random Fluctuations

abstract:
  We propose a new test statistic based on a score process for determining the
statistical significance of a putative signal that may be a small perturbation
to a noisy experimental background. We derive the reference distribution for
this score test statistic; it has an elegant geometrical interpretation as well
as broad applicability. We illustrate the technique in the context of a model
problem from high-energy particle physics. Monte Carlo experimental results
confirm that the score test results in a significantly improved rate of signal
detection.


title: Quo vadis, cold molecules? - Editorial review

abstract:
  We give a snapshot of the rapidly developing field of ultracold polar
molecules abd walk the reader through the papers appearing in this topical
issue.


title: A Quantum Yield Map for Synthetic Eumelanin

abstract:
  The quantum yield of synthetic eumelanin is known to be extremely low and it
has recently been reported to be dependent on excitation wavelength. In this
paper, we present quantum yield as a function of excitation wavelength between
250 and 500 nm, showing it to be a factor of 4 higher at 250 nm than at 500 nm.
In addition, we present a definitive map of the steady-state fluorescence as a
function of excitation and emission wavelengths, and significantly, a
three-dimensional map of the specific quantum yield: the fraction of photons
absorbed at each wavelength that are subsequently radiated at each emission
wavelength. This map contains clear features, which we attribute to certain
structural models, and shows that radiative emission and specific quantum yield
are negligible at emission wavelengths outside the range of 585 and 385 nm (2.2
and 3.2 eV), regardless of excitation wavelength. This information is important
in the context of understanding melanin biofunctionality, and the quantum
molecular biophysics therein.


title:
On Landau's prediction for large-scale fluctuation of turbulence energy
  dissipation

abstract:
  Kolmogorov's theory for turbulence in 1941 is based on a hypothesis that
small-scale statistics are uniquely determined by the kinematic viscosity and
the mean rate of energy dissipation. Landau remarked that the local rate of
energy dissipation should fluctuate in space over large scales and hence should
affect small-scale statistics. Experimentally, we confirm the significance of
this large-scale fluctuation, which is comparable to the mean rate of energy
dissipation at the typical scale for energy-containing eddies. The significance
is independent of the Reynolds number and the configuration for turbulence
production. With an increase of scale r above the scale of largest
energy-containing eddies, the fluctuation becomes to have the scaling r^-1/2
and becomes close to Gaussian. We also confirm that the large-scale fluctuation
affects small-scale statistics.


title:
Synchrotron dynamics in Compton x-ray ring with nonlinear momentum
  compaction

abstract:
  The longitudinal dynamics of electron bunches with a large energy spread
circulating in the storage rings with a small momentum compaction factor is
considered. Also the structure of the longitudinal phase space is considered as
well as its modification due to changes in the ring parameters. The response of
an equilibrium area upon changes of the nonlinear momentum compaction factor is
presented.


title: Tracing the minimum-energy path on the free-energy surface

abstract:
  The free energy profile of a reaction can be estimated in a
molecular-dynamics approach by imposing a mechanical constraint along a
reaction coordinate (RC). Many recent studies have shown that the temperature
can greatly influence the path followed by the reactants. Here, we propose a
practical way to construct the minimum energy path directly on the free energy
surface (FES) at a given temperature. First, we follow the blue-moon ensemble
method to derive the expression of the free energy gradient for a given RC.
These derivatives are then used to find the actual minimum energy reaction path
at finite temperature, in a way similar to the Intrinsic Reaction Path of Fukui
on the potential energy surface [K Fukui J. Phys. Chem. 74, 4161 (1970)]. Once
the path is know, one can calculate the free energy profile using thermodynamic
integration. We also show that the mass-metric correction cancels for many
types of constraints, making the procedure easy to use. Finally, the minimum
free energy path at 300 K for the addition of the 1,1'-dichlorocarbene to
ethylene is compared with a path based on a simple one-dimensional reaction
coordinate. A comparison is also given with the reaction path at 0 K.


title:
Stiff Stability of the Hydrogen atom in dissipative Fokker
  electrodynamics

abstract:
  We introduce an ad-hoc electrodynamics with advanced and retarded
Lienard-Wiechert interactions plus the dissipative Lorentz-Dirac
self-interaction force. We study the covariant dynamical system of the
electromagnetic two-body problem, i.e., the hydrogen atom. We perform the
linear stability analysis of circular orbits for oscillations perpendicular to
the orbital plane. In particular we study the normal modes of the linearized
dynamics that have an arbitrarily large imaginary eigenvalue. These large
eigenvalues are fast frequencies that introduce a fast (stiff) timescale into
the dynamics. As an application, we study the phenomenon of resonant
dissipation, i.e., a motion where both particles recoil together in a drifting
circular orbit (a bound state), while the atom dissipates center-of-mass energy
only. This balancing of the stiff dynamics is established by the existence of a
quartic resonant constant that locks the dynamics to the neighborhood of the
recoiling circular orbit. The resonance condition quantizes the angular momenta
in reasonable agreement with the Bohr atom. The principal result is that the
emission lines of quantum electrodynamics (QED) agree with the prediction of
our resonance condition within one percent average deviation.


title:
Generalized RECPs accounting for Breit effects: uranium, plutonium and
  superheavy elements 112, 113, 114

abstract:
  The Generalized Relativistic Effective Core Potential (GRECP) method is
described which allows one to simulate Breit interaction and finite nuclear
models by an economic way and with high accuracy. The corresponding GRECPs for
the uranium, plutonium, eka-mercury (E112), eka-thallium (E113) and eka-lead
(E114) atoms are generated. The accuracy of these GRECPs and of the RECPs of
other groups is estimated in atomic numerical SCF calculations with Coulomb
two-electron interactions and point nucleus as compared to the corresponding
all-electron Hartree-Fock-Dirac-Breit calculations with the Fermi nuclear
charge distribution. Different nuclear models and contributions of the Breit
interaction between different shells are studied employing all-electron
four-component methods.


title:
First principles study of density, viscosity, and diffusion coefficients
  of liquid MgSiO3 at conditions of the Earth's deep mantle

abstract:
  Constant-pressure constant-temperature {\it ab initio} molecular dynamics
simulations at high temperatures have been used to study MgSiO$_3$ liquid, the
major constituent of the Earth's lower mantle to conditions of the Earth's
core-mantle boundary (CMB). We have performed variable-cell {\it ab initio}
molecular dynamic simulations at relevant thermodynamic conditions across one
of the measured melting curves. The calculated equilibrium volumes and
densities are compared with the simulations using an orthorhombic perovskite
configuration under the same conditions. For molten MgSiO$_3$, we have
determined the diffusion coefficients and shear viscosities at different
thermodynamic conditions. Our results provide new constraints on the properties
of molten MgSiO$_3$ at conditions near the core-mantle boundary. The volume
change on fusion is positive throughout the pressure-temperature conditions
examined and ranges from 5% at 88 GPa and 3500 K to 2.9% at 120 GPa and 5000 K.
Nevertheless, neutral or negatively buoyant melts from (Mg,Fe)SiO$_3$
perovskite compositions at deep lower mantle conditions are consistent with
existing experimental constraints on solid-liquid partition coefficients for
Fe. Our simulations indicate that MgSiO$_3$ is liquid at 120 GPa and 4500 K,
consistent with the lower range of experimental melting curves for this
material. Linear extrapolation of our results indicates that the densities of
liquid and solid perovskite MgSiO$_3$ will become equal near 180 GPa.


title:
An energy interconversion principle applied in reaction dynamics for the
  determination of equilibrium standard states

abstract:
  Chemical theories involving thermodynamical equilibrium states invariably
utilize statistical mechanical equilibrium density distributions. Here, a
definition of heat-work transformation termed thermo mechanical coherence is
first made, and it is conjectured that most molecular bonds have the above
heat-work transformation property, which models a chemical bond as a
"`centrifugal heat engine"' . Expressions are derived for the standard Gibbs
free energy, enthalpy, and entropy where the bond coordinates need not conform
to a non degenerate Boltzmann state, since bond breakdown and formation are
processes that have direction, whereas equilibrium distributions are derived
when the Hamiltonian is of fixed form, which is not the case for chemical
reactions using localized Hamiltonians. The empirically determined Gibbs free
energy from a known molecular dynamics simulation of a dimer reaction 2A-->
A_2, accords rather well with the theoretical estimate. A relation connecting
the rate of reaction with the equilibrium constant and other kinetic parameters
is derived and could place the commonly observed linear relationship between
the logarithms of the rate constant and equilibrium constant on a firmer
theoretical footing. These relationships could include analogues of the Hammett
correlations used extensively in physical organic chemistry, as well as others
which are temperature dependent.


title: Anomalous waiting times in high-frequency financial data

abstract:
  In high-frequency financial data not only returns, but also waiting times
between consecutive trades are random variables. Therefore, it is possible to
apply continuous-time random walks (CTRWs) as phenomenological models of the
high-frequency price dynamics. An empirical analysis performed on the 30 DJIA
stocks shows that the waiting-time survival probability for high-frequency data
is non-exponential. This fact imposes constraints on agent-based models of
financial markets.


title:
Resonant backward scattering of light by a two-side-open subwavelength
  metallic slit

abstract:
  The backward scattering of TM-polarized light by a two-side-open
subwavelength slit in a metal film is analyzed. We show that the reflection
coefficient versus wavelength possesses a Fabry-Perot-like dependence that is
similar to the anomalous behavior of transmission reported in the study [Y.
Takakura, Phys. Rev. Lett. \textbf{86}, 5601 (2001)]. The open slit totally
reflects the light at the near-to-resonance wavelengths. In addition, we show
that the interference of incident and resonantly backward-scattered light
produces in the near-field diffraction zone a spatially localized wave whose
intensity is 10-10$^3$ times greater than the incident wave, but one order of
magnitude smaller than the intra-cavity intensity. The amplitude and phase of
the resonant wave at the slit entrance and exit are different from that of a
Fabry-Perot cavity.


title:
The use of a syncytium model of the crystalline lens of the human eye to
  study the light flashes seen by astronauts

abstract:
  A syncytium model to study some electrical properties of the eye is proposed
in the attempt to explain the phenomenon of anomalous Light Flashes (LF)
perceived by astronauts in orbit. The crystalline lens is modelled as an
ellipsoidal syncytium having a variable relative dielectric constant. The
mathematical model proposed is given by a boundary value problem for a system
of two coupled elliptic partial differential equations in two unknowns. We use
a numerical method to compute an approximate solution of this mathematical
model and we show some numerical results that provide a possible (qualitative)
explanation of the observed LF phenomenon. In particular, we calculate the
energy lost in the syncytium by a cosmic charged particle that goes through the
syncytium and compare the results with those obtained using the Geant 3.21
simulation program. We study the interaction antimatter-syncytium. We use the
Creme96 computer program to evaluate the cosmic ray fluxes encountered by the
International Space Station.


title:
Self-similarities in the frequency-amplitude space of a loss-modulated
  CO$_2$ laser

abstract:
  We show the standard two-level continuous-time model of loss-modulated CO$_2$
lasers to display the same regular network of self-similar stability islands
known so far to be typically present only in discrete-time models based on
mappings. For class B laser models our results suggest that, more than just
convenient surrogates, discrete mappings in fact could be isomorphic to
continuous flows.

categories: physics.optics math.DS nlin.CD physics.gen-ph quant-ph


title:
Dynamics of Air-Fluidized Granular System Measured by the Modulated
  Gradient Spin-echo

abstract:
  The power spectrum of displacement fluctuation of beads in the air-fluidized
granular system is measured by a novel NMR technique of modulated gradient
spin-echo. The results of measurement together with the related spectrum of the
velocity fluctuation autocorrelation function fit well to an empiric formula
based on to the model of bead caging between nearest neighbours; the cage
breaks up after a few collisions \cite{Menon1}. The fit yields the
characteristic collision time, the size of bead caging and the diffusion-like
constant for different degrees of system fluidization. The resulting mean
squared displacement increases proportionally to the second power of time in
the short-time ballistic regime and increases linearly with time in the
long-time diffusion regime as already confirmed by other experiments and
simulations.


title:
Mapping of periodically poled crystals via spontaneous parametric
  down-conversion

abstract:
  A new method for characterization of periodically poled crystals is developed
based on spontaneous parametric down-conversion. The method is demonstrated on
crystals of Y:LiNbO3, Mg:Y:LiNbO3 with non-uniform periodically poled
structures, obtained directly under Czochralski growth procedure and designed
for application of OPO in the mid infrared range. Infrared dispersion of
refractive index, effective working periods and wavelengths of OPO were
determined by special treatment of frequency-angular spectra of spontaneous
parametric down-conversion in the visible range. Two-dimensional mapping via
spontaneous parametric down-conversion is proposed for characterizing spatial
distribution of bulk quasi-phase matching efficiency across the input window of
a periodically poled sample.


title:
On the Energy-Time Uncertainty Relations: A didactical note for
  undergraduate students

abstract:
  The purpose of this brief note is that of discussing the meaning of the
uncertainty relations involving energy and time in quantum mechanics by means
of a reading of the classical works on the subject. This was written for
undergraduate students attending to an introductory course in quantum
mechanics.


title:
Mechanism of the Dark Matter and Condensed Bubble Objects Formation in
  the Model of Extended Space

abstract:
  Within the framework of Extended Space Model (ESM) the processes connected to
birth of photons in a gravitational field are studied. These photons have a
nonzero mass. It can be both positive, and negative, and photon's energy and
strength of the gravitational field determine its absolute value. It is shown
that in ESM model formation of bubble gravitational structures is possible. In
the frame of ESM one can obtain the follow physical picture. Bubble
gravitational objects have a halo formed by dark matter generated by photons
with a positive mass. The photons with a negative mass are throw away in free
deep space and create there antigravitating vacuum with negative pressure. The
comparison ESM bubble structures with similar objects of a type "gravastar",
existing in a General Theory of Relativity (GR) is made.


title: Global permanent deformations triggered by the Sumatra earthquake

abstract:
  The giant Sumatra-Andaman earthquake of December 26 2004 caused permanent
deformations effects in a region of previously never observed extension. The
GPS data from the world wide network of permanent IGS sites show significant
coseismic displacements in an area exceeding 107 km^2. The effects of the
permanent residual deformation field could be detected as far as Australia, the
Phillipines and Japanese archipelagos, and, on the West, as far as the indian
continent. The synthetic simulations of the coseismic displacement field
obtained by means of a spherical model support the hypothesis that a
considerable amount of energy has been released aseismically.


title:
The physical origin of the Fresnel drag of light by a moving dielectric
  medium

abstract:
  We present a new derivation of the Fresnel-Fizeau formula for the drag of
light by a moving medium using a simple perturbation approach. We focus
particulary on the physical origin of the phenomenon and we show that it is
very similar to the Doppler-Fizeau effect. We prove that this effect is, in its
essential part, independent of the theory of relativity. The possibility of
applications in other domains of physics is considered.


title:
Precision test for the new Michelson-Morley experiments with rotating
  cryogenic cavities

abstract:
  A new ether-drift experiment in D\"usseldorf is currently measuring the
relative frequency shift of two cryogenic optical resonators upon active
rotations of the apparatus. I point out that the observed fractional amplitude
of the sidereal variations of the signal in February, C_sid \sim (11 \pm 2)
10^{-16}, is entirely consistent with the expectations based on Miller's
observations in the same epoch of the year. This leads to predict that, with
future data collected in August-September, the observed sidereal variations
should increase by \sim + 70 %, i.e. up to C_sid \sim (19\pm 2) 10^{-16}
retaining the present normalization. This would represent clean experimental
evidence for the existence of a preferred frame.


title:
Robustness of One-Dimensional Photonic Bandgaps Under Random Variations
  of Geometrical Parameters

abstract:
  The supercell method is used to study the variation of the photonic bandgaps
in one-dimensional photonic crystals under random perturbations to thicknesses
of the layers. The results of both plane wave and analytical band structure and
density of states calculations are presented along with the transmission
cofficient as the level of randomness and the supercell size is increased. It
is found that higher bandgaps disappear first as the randomness is gradually
increased. The lowest bandgap is found to persist up to a randomness level of
55 percent.


abstract:
  Multi-electron giant dipole resonances of atoms in crossed electric and
magnetic fields are investigated. Stationary configurations corresponding to a
highly symmetric arrangement of the electrons on a decentered circle are
derived, and a normal-mode stability analysis is performed. A classification of
the various modes, which are dominated either by the magnetic or Coulomb
interactions, is provided. A six-dimensional wave-packet dynamical study, based
on the MCTDH approach, is accomplished for the two-electron resonances,
yielding in particular lifetimes of more than 0.1 $\mu$s for strong electric
fields.


title:
Preliminary study of metabolic radiotherapy with 188Re via small animal
  imaging

abstract:
  188Re is a beta- (Emax = 2.12 MeV) and gamma (155 keV) emitter. Since its
chemistry is similar to that of the largely employed tracer, 99mTc, molecules
of hyaluronic acid (HA) have been labelled with 188Re to produce a target
specific radiopharmaceutical. The radiolabeled compound, i.v. injected in
healthy mice, is able to accumulate into the liver after a few minutes. To
study the effect of metabolic radiotherapy in mice, we have built a small gamma
camera based on a matrix of YAP:Ce crystals, with 0.6x0.6x10 mm**3 pixels, read
out by a R2486 Hamamatsu PSPMT. A high-sensitivity 20 mm thick lead
parallel-hole collimator, with hole diameter 1.5 mm and septa of 0.18 mm, is
placed in front of the YAP matrix. Preliminary results obtained with various
phantoms containing a solution of 188Re and with C57 black mice injected with
the 188Re-HA solution are presented. To increase the space resolution and to
obtain two orthogonal projections simultaneously we are building in parallel
two new cameras to be positioned at 90 degrees. They use a CsI(Tl) matrix with
1x1x5 mm**3 pixels read out by H8500 Hamamatsu Flat panel PMT.


title: The Network Analysis of Urban Streets: A Primal Approach

abstract:
  The network metaphor in the analysis of urban and territorial cases has a
long tradition especially in transportation/land-use planning and economic
geography. More recently, urban design has brought its contribution by means of
the "space syntax" methodology. All these approaches, though under different
terms like accessibility, proximity, integration,connectivity, cost or effort,
focus on the idea that some places (or streets) are more important than others
because they are more central. The study of centrality in complex
systems,however, originated in other scientific areas, namely in structural
sociology, well before its use in urban studies; moreover, as a structural
property of the system, centrality has never been extensively investigated
metrically in geographic networks as it has been topologically in a wide range
of other relational networks like social, biological or technological. After
two previous works on some structural properties of the dual and primal graph
representations of urban street networks (Porta et al. cond-mat/0411241;
Crucitti et al. physics/0504163), in this paper we provide an in-depth
investigation of centrality in the primal approach as compared to the dual one,
with a special focus on potentials for urban design.


title: Sifting data in the real world

abstract:
  In the real world, experimental data are rarely, if ever, distributed as a
normal (Gaussian) distribution. As an example, a large set of data--such as the
cross sections for particle scattering as a function of energy contained in the
archives of the Particle Data Group--is a compendium of all published data, and
hence, unscreened. Inspection of similar data sets quickly shows that, for many
reasons, these data sets have many outliers--points well beyond what is
expected from a normal distribution--thus ruling out the use of conventional
$\chi^2$ techniques. This note suggests an adaptive algorithm that allows a
phenomenologist to apply to the data sample a sieve whose mesh is coarse enough
to let the background fall through, but fine enough to retain the preponderance
of the signal, thus sifting the data. A prescription is given for finding a
robust estimate of the best-fit model parameters in the presence of a noisy
background, together with a robust estimate of the model parameter errors, as
well as a determination of the goodness-of-fit of the data to the theoretical
hypothesis. Extensive computer simulations are carried out to test the
algorithm for both its accuracy and stability under varying background
conditions.


title:
Electron Correlation Effects in Hyperfine Interactions in $^{45}$Sc and
  $^{89}$Y

abstract:
  The relativistic coupled-cluster theory has been employed to calculate the
magnetic dipole and electric quadrupole hyperfine structure constants for the
stable isotopes $^{45}$Sc and $^{89}$Y. The role of electron correlation is
found to be very important. The trend exhibited by these effects is rather
different from previously studied single valence atomic systems.


title: Inversions of the Effective Action in Condensed Matter Models

abstract:
  The quantum effective action may be used to invert information from
phenomena, either measured or ideal, to the microscopic Lagrangian. As an
example of this procedure the lattice composition of a solid can be determined
in principle from desired critical phenomena. Also, the engineering of
scattering and optical properties of particular degrees of freedom, and
excitations, in terms of the temperature and electro-magnetic fields may be
performed.


title: A Map from Scalar Field Theory to Integer Polynomial Solutions

abstract:
  The terms in the quantum scattering in scalar field theory models is
parameterized by the invariants $\prod s_{ij}^{n_{ij}}$. The $s_{ij}$ are
kinematic two-particle invariants, and the $n_{ij}$ are integers. The
coefficients of these terms are computed via integrating all Feynman diagrams,
or within the derivative expansion by solving the iteration equations. The
latter has been provided recently; the functions which are prefactors of the
individual terms $\prod s_{ij}^{n_{ij}}$ can be interpreted as terms in the
expansions of L-series, which may be specified by collections of their zeroes.
Once finding the appropriate elliptic curve coefficients, these quantum field
solutions provide an algorithm to determining all of the mod p zeros to the
algebraic curves. The latter is presumably determined by 'experimental'
computer modeling or by the appropriate determination of the quantum
prefactors.


title: Intra-cellular transport of single-headed molecular motors KIF1A

abstract:
  Motivated by experiments on single-headed kinesin KIF1A, we develop a model
of intra-cellular transport by interacting molecular motors. It captures
explicitly not only the effects of ATP hydrolysis, but also the ratchet
mechanism which drives individual motors. Our model accounts for the
experimentally observed single molecule properties in the low density limit and
also predicts a phase diagram that shows the influence of hydrolysis and
Langmuir kinetics on the collective spatio-temporal organization of the motors.
Finally, we provide experimental evidence for the existence of domain walls in
our {\it in-vitro} experiment with fluorescently labeled KIF1A.


title: Development of a TDC to equip a Liquid Xenon PET prototype

abstract:
  A Time to Digital Converter was designed (CMOS 0.35 $\mum) in order to be
used in Liquid Xenon PET prototype. The circuit proved to be able to work at
-120 degrees C, while showing a resolution of 250 ps. The circuit enables a low
readout dead time (<90 ns) and provides a fully synchronous digital interface
for easy data retrieval.


title:
Summary of experimental studies at CERN on a positron source using
  crystal effects

abstract:
  New kind of positron sources for future linear colliders, where the converter
is a tungsten crystal oriented on the <111> axis, has been studied at CERN in
the WA103 experiment. In such sources the photons which create the $e^+ e^-$
pairs result from channeling radiation and coherent bremsstrahlung. In this
experiment electron beams of 6 and 10 GeV were sent on different kinds of
targets: a 4 mm thick crystal, a 8 mm thick crystal and a compound taraget (4
mm crystal + 4 mm amorphous disk). An amorphous tungsten target 20 mm thick was
also used for comparison with the 8 mm crystal. Tracks of outgoing charged
particles were detected and analyzed by a drift chamber in a magnetic field.
The energy and angle spectra of the positrons were obtained for energies up to
150 MeV and angles up to 30 degrees. The measured positron distribution in
momentum space (longitudinal versus transverse) is also presented, giving a
full momentum space description of the source. Results on outgoing photons are
also presented. A significant enhancement of both photon and positron
production is clearly observed. At 10 GeV incident energy, the positron
enhancement factor is 4 for the 4 mm crystal, about 2 for the 8 mm crystal.
Besides, the simulation code for the crystal processes is validated by a quite
good agreement between the simulated and experimental spectra, both for
positrons and photons.


title:
Zero-point energy of vacuum fluctuation as a candidate for dark energy
  versus a new conjecture of antigravity based on the modified Einstein field
  equation in general relativity

abstract:
  In order to clarify why the zero-point energy associated with the vacuum
fluctuations cannot be a candidate for the dark energy in the universe, a
comparison with the Casimir effect is analyzed in some detail. A principle of
epistemology is stressed that it is meaningless to talk about an absolute
(isolated) thing. A relative thing can only be observed when it is changing
with respect to other things. Then a new conjecture of antigravity --the
repulsive force between matter and antimatter derived from the modified
Einstein field equation in general relativity-- is proposed. this is due to the
particle-antiparticle symmetry based on a new understanding about the essence
of special relativity. Its possible consequences in the theory of cosmology are
discussed briefly, including a new explanation for the accelerating universe
and gamma-ray-bursts.


title:
The theory of focusing of high energy ions by bent crystals of special
  shape

abstract:
  In this report we present the detail theory of the focusing in bent crystals
using the statistical mechanics. The quantum mechanical effects for focusing
and abberations are not considered. The beam structure in phase space are
consedered and envelope near the focusing spot and intensity profile are
derived.


title:
Hydrogen atom and one-electron molecular systems in a strong magnetic
  field: are all of them alike?

abstract:
  Easy physics-inspired approximations of the total and binding energies for
the ${\rm H}$ atom and for the molecular ions $${\rm H}_2^{(+)} ({\rm ppe}),
{\rm H}_3^{(2+)} ({\rm pppe}), ({\rm HeH})^{++} (\al {\rm p e}), {\rm
He}_2^{(3+)} (\al \al {\rm e})$$ as well as quadrupole moment for the ${\rm H}$
atom and the equilibrium distances of the molecular ions in strong magnetic
fields $> 10^{9}$ G are proposed. The idea of approximation is based on the
assumption that the dynamics of the one-electron Coulomb system in a strong
magnetic field is governed by the ratio of transverse to longitudinal sizes of
the electronic cloud.


title: Permutation sampling in Path Integral Monte Carlo

abstract:
  A simple algorithm is described to sample permutations of identical particles
in Path Integral Monte Carlo (PIMC) simulations of continuum many-body systems.
The sampling strategy illustrated here is fairly general, and can be easily
incorporated in any PIMC implementation based on the staging algorithm.
Although it is similar in spirit to an existing prescription, it differs from
it in some key aspects. It allows one to sample permutations efficiently, even
if long paths (e.g., hundreds, or thousands of slices) are needed. We
illustrate its effectiveness by presenting results of a PIMC calculation of
thermodynamic properties of superfluid Helium-four, in which a very simple
approximation for the high-temperature density matrix was utilized.


title: An agent-based model to rural-urban migration analysis

abstract:
  In this paper we analyze the rural-urban migration phenomena as it is usually
observed in economies which are in the early stages of industrialization. The
analysis is conducted by means of a statistical mechanics approach which builds
a computational agent-based model. Agents are placed on a lattice and the
connections among them are described via an Ising like model. Simulations on
this computational model show some emergent properties that are common in
developing economies, such as a transitional dynamics characterized by
continuous growth of urban population, followed by the equalization of expected
wages between rural and urban sectors (Harris-Todaro equilibrium condition),
urban concentration and increasing of per capita income.


title:
Two-dimensional atomic lithography by sub-micron focusing of atomic
  beams

abstract:
  We analyze a method for serial writing of arbitrary two-dimensional patterns
using optical focusing of a collimated atomic beam. A spatial light modulator
is used in a side illumination geometry to create a localized optical spot with
secondary maxima that are well separated from the central peak. Numerical
simulation of a lithography experiment using a magneto-optical trap as a source
of cold Cs atoms, collimation and cooling in a magnetic guide, and optical
focusing predicts full width at half maximum pixel sizes of 110 x 110 nm and
writing times of about $20 \rm ms$ per pixel.


title: The arrow of time in quantum mechanics and in nonlinear optics

abstract:
  The direct and indirect experimental proofs of a strong time invariance
violation in optics are discussed. Time noninvariance for present day becomes
the only real physical base for explanation the origin of the most phenomena in
nonlinear optics. This is a good cause to introduce the time asymmetry into the
dynamical equations of the basic laws of physics.


title: On the displacements of Einsteinian fields et cetera

abstract:
  I give here: i) a very simple proof that the physical non-existence of
gravitational waves (GW's) is quite consistent with the basic principles of
general relativity (GR); ii) a new argument against the physical existence of
GW's; iii) a criticism of Fock's treatment of the GW's; iv) some remarks on
recent experimental investigations concerning the GW's.


title:
Dicke Coherent Narrowing in Two-Photon and Raman Spectroscopy of Thin
  Vapour Cells

abstract:
  The principle of coherent Dicke narrowing in a thin vapour cell, in which
sub-Doppler spectral lineshapes are observed under a normal irradiation for a
l/2 thickness, is generalized to two-photon spectroscopy. Only the sum of the
two wave vectors must be normal to the cell, making the two-photon scheme
highly versatile. A comparison is provided between the Dicke narrowing with
copropagating fields, and the residual Doppler-broadening occurring with
counterpropagating geometries. The experimental feasibility is discussed on the
basis of a first observation of a two-photon resonance in a 300 nm-thick Cs
cell. Extension to the Raman situation is finally considered.


title: Parametric Autoresonance in Faraday waves

abstract:
  We develop a theory of parametric excitation of weakly nonlinear standing
gravity waves in a tank, which is under vertical vibrations with a slowly
time-dependent ("chirped") vibration frequency. We show that, by using a
negative chirp, one can excite a steadily growing wave via parametric
autoresonance. The method of averaging is employed to derive the governing
equations for the primary mode. These equations are solved analytically and
numerically, for typical initial conditions, for both inviscid and weakly
viscous fluids. It is shown that, when passing through resonance, capture into
resonance always occurs when the chirp rate is sufficiently small. The critical
chirp rate, above which breakdown of autoresonance occurs, is found for
different initial conditions. The autoresonance excitation is expected to
terminate at large amplitudes, when the underlying constant-frequency system
ceases to exhibit a non-trivial stable fixed point.


title: Is There a Real-Estate Bubble in the US?

abstract:
  We analyze the quarterly average sale prices of new houses sold in the USA as
a whole, in the northeast, midwest, south, and west of the USA, in each of the
50 states and the District of Columbia of the USA, to determine whether they
have grown faster-than-exponential which we take as the diagnostic of a bubble.
We find that 22 states (mostly Northeast and West) exhibit clear-cut signatures
of a fast growing bubble. From the analysis of the S&P 500 Home Index, we
conclude that the turning point of the bubble will probably occur around
mid-2006.


title:
Influence of saving propensity on the power law tail of wealth
  distribution

abstract:
  Some general features of kinetic multi-agent models are reviewed, with
particular attention to the relation between the agent saving propensities and
the form of the equilibrium wealth distribution. The effect of a finite cutoff
of the saving propensity distribution on the corresponding wealth distribution
is studied. Various results about kinetic multi-agent models are collected and
used to construct a realistic wealth distribution with zero limit for small
values of wealth, an exponential form at intermediate and a power law tail at
larger values of wealth.


title: Black Hole Radiation and Volume Statistical Entropy

abstract:
  The simplest possible equation for Hawking radiation, and other black hole
radiated power is derived in terms of black hole density. Black hole density
also leads to the simplest possible model of a gas of elementary constituents
confined inside a gravitational bottle of Schwarzchild radius at tremendous
pressure, which yields identically the same functional dependence as the
traditional black hole entropy. Variations of Sbh can be obtained which depend
on the occupancy of phase space cells. A relation is derived between the
constituent momenta and the black hole radius which is similar to the Compton
wavelength relation.


title:
Sampling errors of correlograms with and without sample mean removal for
  higher-order complex white noise with arbitrary mean

abstract:
  We derive the bias, variance, covariance, and mean square error of the
standard lag windowed correlogram estimator both with and without sample mean
removal for complex white noise with an arbitrary mean. We find that the
arbitrary mean introduces lag dependent covariance between different lags of
the correlogram estimates in spite of the lack of covariance in white noise for
non-zeros lags. We provide a heuristic rule for when the sample mean should be,
and when it should not be, removed if the true mean is not known. The sampling
properties derived here are useful is assesing the general statistical
performance of autocovariance and autocorrelation estimators in different
parameter regimes. Alternatively, the sampling properties could be used as
bounds on the detection of a weak signal in general white noise.


title:
Nanostructures and enhanced absorption in intense laser interaction with
  matter: effect of laser prepulses

abstract:
  Hard x-ray emission (20 - 200 keV) from plasmas produced by intense laser
pulses on nanoparticle coated targets is compared with that from optically
polished targets. The yield enhancement offered by nanoparticles is studied
under different prepulse conditions. It is observed that the enhancement
reduces when the nanoparticle coated target is irradiated with a prepulse with
intensity greater than 10^13 W/cm^2. When the prepulse intensity exceeds 10^14
W/cm^2, the enhancement vanishes completely. This is attributed to preplasma
formation on nanoparticles their subsequent structural modifcation before the
arrival of the main pulse. It is suggested that high-contrast ultrashort pulses
are essential for nanoparticles to function as yield enhancers.


title: The Projectile inside the Loop

abstract:
  In this paper we describe an alternative use of the loop-the-loop apparatus,
which can be used to study an interesting case of projectile motion. We also
present an effective way to perform and analyze these experiments, by using
video capture software together with a digital video camera. These experiments
can be integrated into classroom demonstrations for general physics courses, or
become part of laboratory activities.


title: Complex Relativity: Gravity and Electromagnetic Fields

abstract:
  We present new aspects of the electromagnetic field by introducting the
natural potentials. These natural potentials are suitable for constructing the
first order distortions of the metric tensor of Complex Relativity - the theory
combining the General Relativity with the electromagnetic equations. A
transition from antisymmetric tensors to the symmetric ones helps to define the
natural potentials; their form fits a system of the Dirac matrices and this
representation leads to distortion of the metric tensor.
  Our considerations have originated from the recent progresses in the
asymmetric continuum theories. One version of such theories assumes an
existence of the antisymmetric strain and stress fields; these fields originate
due to some kind of internal friction in a continuum medium which have elastic
bonds related to rotations of the particles.


title:
Absense of slow transients, and the effect of imperfect vertical
  alignment, in turbulent Rayleigh-Benard convection

abstract:
  We report experimental results for the influence of a tilt angle beta
relative to gravity on turbulent Rayleigh-Benard convection of cylindrical
samples. The measurements were made at Rayleigh numbers R up to 10^11 with two
samples of height L equal to the diameter D (aspect ratio Gamma = D/L = 1). The
fluid was water with a Prandtl number sigma = 4.38. In contrast to the
experiences reported by Chilla et. al. (2004) for a similar sample but with
Gamma = 0.5 (D = 0.5 and L = 1.0 m), we found no long relaxation times. For R =
9.4 times 10^10 we measured the Nusselt number N as a function of tilt angle
beta and obtained a small beta dependence about a factor of 50 smaller than the
result found by Chilla et. al. (2004) for their Gamma = 0.5 sample. We measured
side-wall temperatures at eight equally spaced azimuthal locations on the
horizontal mid-plane of the sample and used their cross-correlation functions
to find the turn-over time of the large-scale circulation (LSC). The resulting
Reynolds numbers R_e^cc were found to increase with beta. An important
conclusion is that the increase of R_e^cc with beta of the LSC does not
significantly influence the heat transport. Over the range 10^9 < R < 10^11 the
enhancement of R_e^cc at constant beta due to the tilt could be described by a
power law of R with an exponent of -1/6, consistent with a simple model that
balances the additional buoyancy due to the tilt angle by the shear stress
across the boundary layers. Even a small tilt angle dramatically suppressed the
azimuthal meandering and the sudden reorientations characteristic of the LSC in
a sample with beta = 0. The azimuthal mean of the temperature at the horizontal
mid-plane within our resolution was independent of beta.


title: Core-periphery organization of complex networks

abstract:
  Networks may, or may not, be wired to have a core that is both itself densely
connected and central in terms of graph distance. In this study we propose a
coefficient to measure if the network has such a clear-cut core-periphery
dichotomy. We measure this coefficient for a number of real-world and model
networks and find that different classes of networks have their characteristic
values. For example do geographical networks have a strong core-periphery
structure, while the core-periphery structure of social networks (despite their
positive degree-degree correlations) is rather weak. We proceed to study radial
statistics of the core, i.e. properties of the n-neighborhoods of the core
vertices for increasing n. We find that almost all networks have unexpectedly
many edges within n-neighborhoods at a certain distance from the core
suggesting an effective radius for non-trivial network processes.


title: One-loop self-energy correction in a strong binding field

abstract:
  A new scheme for the numerical evaluation of the one-loop self-energy
correction to all orders in Z \alpha is presented. The scheme proposed inherits
the attractive features of the standard potential-expansion method but yields a
partial-wave expansion that converges more rapidly than in the other methods
reported in the literature.


title: State-Specific Kohn-Sham Density Functional Theory

abstract:
  A generalization of the Kohn--Sham approach is derived where the
correlation-energy functional depends on the one-particle density matrix of
noninteracting states and on the external potential from the interacting
target-state. The one-particle equations contain the exact exchange potential,
a nonlocal correlation potential, and an additional operator involving the
correlation density. The electronic-energy functional has multiple solutions:
Any one-particle density matrix delivering the target-state density yields a
solution. In order to obtain the Kohn--Sham solution, the nonlocal operators
are converted into local ones using an approach developed by Sala and Gorling.
Since the exact exchange-potential is used, and the N--representability problem
does not arise--in contrast to the Kohn--Sham approach--errors from Coulomb
self-interactions do not occur, nor the need to introduce functionals defined
by a constraint search. Furthermore, the approach does not use the
Hohenberg-Kohn theorem. A density functional formalism is also derived that
assumes that the one-particle density matrices of interest have v-representable
(non-interacting) densities and that these density matrices can be written as
an explicit functional of the electron density. For simplicity, we only
consider noninteracting closed-shell states and target states that are
nondegenerate, singlet ground-states.


title: Study of P,T-Parity Violation Effects in Polar Heavy-Atom Molecules

abstract:
  Investigation of P,T-parity nonconservation (PNC) phenomena is of fundamental
importance for physics. Experiments to search for PNC effects have been
performed on TlF and YbF molecules and are in progress for PbO and PbF
molecules. For interpretation of molecular PNC experiments it is necessary to
calculate those needed molecular properties which cannot be measured. In
particular, electronic densities in heavy-atom cores are required for
interpretation of the measured data in terms of the P,T-odd properties of
elementary particles or P,T-odd interactions between them. Reliable
calculations of the core properties (PNC effect, hyperfine structure etc.,
which are described by the operators heavily concentrated in atomic cores or on
nuclei) usually require accurate accounting for both relativistic and
correlation effects in heavy-atom systems. In this paper, some basic aspects of
the experimental search for PNC effects in heavy-atom molecules and the
computational methods used in their electronic structure calculations are
discussed. The latter include the generalized relativistic effective core
potential (GRECP) approach and the methods of nonvariational and variational
one-center restoration of correct shapes of four-component spinors in atomic
cores after a two-component GRECP calculation of a molecule. Their efficiency
is illustrated with calculations of parameters of the effective P,T-odd
spin-rotational Hamiltonians in the molecules PbF, HgF, YbF, BaF, TlF, and PbO.


title: The Sagnac effect in Coupled-Resonator Slow-Light Waveguide Structures

abstract:
  We study the effect of rotation on the propagation of electromagnetic waves
in slow-light waveguide structures consisting of coupled micro-ring resonators.
We show that such configurations exhibit new a type of the Sagnac effect which
can be used for the realization of highly-compact integrated rotation sensors
and gyroscopes.


title: Coexisting Spacetimes in the Solar Neighborhood

abstract:
  We consider the proposition that multiple universes exist by reviewing the
various manifestations. In recent years, this idea has been elevated from
science fiction and introduced in separate guises as an explanation for
coincidence problems in cosmology, the prediction of dark energy, gravitational
anomalies, a consequence of string theory, an extension of inflation, and
conceptual issues in quantum mechanics. However, there appears to be no single
consistent formalism that addresses all the issues - it is not even clear if
the multiple universes interact or are accessible. Because of the absence of
clear evidence, it is easy to dismiss claims for multiple Universes, but it is
not that simple: Space-time geometries in a variety of forms are an established
aspect of physics, and history has shown that things which are not expressly
forbidden often appear at a later date. With this in mind, a new example of
possible multiple geometries is introduced to explain a difficult problem in
cosmology: Why are distant galaxies subject to the Hubble expansion but rulers
within our galaxy (and presumably, by the Cosmological Principle, all other
galaxies) do not appear to expand? There has actually been much debate in
recent years about whether local systems really are subject to the cosmological
expansion; we adopt the established view that local systems are not expanding
and investigate the transition condition where a mass may be part of the static
galactic system or participate in the expansion. We show that a remarkably
simple model based on coexisting spacetimes clarifies the situation and makes
quantative, testable cosmological predictions. The model is also testable
through Earth-based experiments.


title: Engineering the Quantum Foam

abstract:
  In 1990 Alcubierre, within the General Relativity model for space-time,
proposed a scenario for `warp drive' faster than light travel, in which objects
would achieve such speeds by actually being stationary within a bubble of space
which itself was moving through space, the idea being that the speed of the
bubble was not itself limited by the speed of light. However that scenario
required exotic matter to stabilise the boundary of the bubble. Here that
proposal is re-examined within the context of the new modelling of space in
which space is a quantum system, viz a quantum foam, with on-going
classicalisation. This model has lead to the resolution of a number of
longstanding problems, including a dynamical explanation for the so-called
`dark matter' effect. It has also given the first evidence of quantum gravity
effects, as experimental data has shown that a new dimensionless constant
characterising the self-interaction of space is the fine structure constant.
The studies here begin the task of examining to what extent the new spatial
self-interaction dynamics can play a role in stabilising the boundary without
exotic matter, and whether the boundary stabilisation dynamics can be
engineered; this would amount to quantum gravity engineering.