title:
Magnetization of rotating ferrofluids: predictions of different
  theoretical models

abstract:
  We consider a ferrofluid cylinder, that is rotating with constant rotation
frequency \Omega e_z as a rigid body. A homogeneous magnetic field H_0 e_x is
applied perpendicular to the cylinder axis e_z. This causes a nonequilibrium
situation. Therein the magnetization M and the internal magnetic field H are
constant in time and homogeneous within the ferrofluid. According to the
Maxwell equations they are related to each other via H = H_0 - M/2. However, H
and M are not parallel to each other and their directions differ from that of
the applied field H_0. We have analyzed several different theoretical models
that provide equations for the magnetization in such a situation. The
magnetization M is determined for each model as a function of \Omega and H_0 in
a wide range of frequencies and fields. Comparisons are made of the different
model results and the differences in particular of the predictions for the
perpendicular components H_y =-M_y/2 of the fields are analyzed.


title: Radiative Transfer and Atom Transport

abstract:
  The report deals with classical and quantum descriptions of particles that
interact with smooth random potentials, for example ultracold atoms in the
dipole potential of an optical speckle pattern. In addition, a discussion of
the link between Radiative Transfer theory and the underlying coherence theory
of wave optics is presented. The Radiative Transfer Equation is shown to emerge
as a limiting case of the Bethe-Salpeter Equation, and some next-order
corrections are discussed.


title:
Strongly anisotropic media: the THz perspectives of left-handed
  materials

abstract:
  We demonstrate that non-magnetic ($\mu \equiv 1$) left-handed materials can
be effectively used for waveguide imaging systems. We also propose a specific
THz realization of the non-magnetic left-handed material based on homogeneous,
naturally-occurring media.


title:
Relativistic velocity transformation as a genitor of transformation
  equations (relativistic dynamics)

abstract:
  The fundamental equations of relativistic dynamics are derived from a thought
experiment and from the transformation of relativistic velocity avoiding
collisions and conservation laws of momentum and energy.


title:
A Program for Integrating Math and Physics Internet-Based Teaching Tools
  into Large University Physics Courses

abstract:
  Significant obstacles prevent large, university-level, introductory physics
courses from effectively teaching problem-solving skills. We describe our
program for integrating three internet-based "teaching-while-quizzing" tools to
address two of these barriers: students' poor math skills and instructors'
insufficient grading recourses. We outline our system of math remediation,
homework and after-homework quizzes, and mini-practice exams, and demonstrate
how it can be incorporated into courses with modest instructor effort.


title:
Whitehead's Principle of Relativity - Unpublished Lectures by J. L.
  Synge, FRS

abstract:
  In Appendix B, there is a proposal about the Limb Effect which could be of
great significance for Solar Physics.
  In his PRINCIPLE OF RELATIVITY, Cambridge University Press, 1922 (republished
Dover, 2004) A. N. Whitehead, making no use of ''curved'' space-time, derived
the same values as Einstein for the red-shift, perihelion advance and the
deflection of light. Synge expounds Whitehead's arguments in modern notation
making it more accessible for contemporary Physicists but also obtains the
Shapiro retardation of electromagnetic radiation by a gravitational field.
Synge compares Einstein's GRT and Whitehead's PR, finding the observational
evidence equally strong for both theories. He alluded to Whitehead's prediction
of a Limb Effect remarking that to pursue its consequences would require a
knowledge of QM which did not exist in 1922. Possibly this was not done because
of physicist's Obsession with GRT since 1919.


title:
Electrothermal vaporization with axially focusing convection upstream:
  effects of graphite furnace carbon and K/Pd modifiers on analyte transport

abstract: This paper has been withdrawn by the author because of copyright reasons.


title: The spectra of mixed $^3$He-$^4$He droplets

abstract:
  The diffusion Monte Carlo technique is used to calculate and analyze the
excitation spectrum of $^3$He atoms bound to a cluster of $^4$He atoms, by
using a previously determined optimum filling of single-fermion orbits with
well defined orbital angular momentum $L$, spin $S$ and parity quantum numbers.
The study concentrates on the energies and shapes of the three kinds of states
for which the fermionic part of the wave function is a single Slater
determinant: maximum $L$ or maximum $S$ states within a given orbit, and fully
polarized clusters. The picture that emerges is that of systems with strong
shell effects whose binding and excitation energies are essentially determined
over configuration at fixed number of particles and spin, i.e., by the monopole
properties of an effective Hamiltonian.


title:
Gravity is indeed the driving force for fault pattern formation and
  westward displacement of the lithosphere

abstract:
  Gravity influence of the Sun and the Moon on the Earth is the cause of the
fault pattern on Earth's surface we observe nowadays and also of the westward
displacement of the lithosphere. A somewhat related hypotheses advanced in the
past have been that tidal torque of the Moon may be significant. However, it
has been argued that it is untenable essentially on the grounds that the
viscosity of the Earth's mantle is far too high in comparison with the forces
involved. To state this it was assumed that the Earth's relevant characteristic
is that of two spherical shells separated by a viscous liquid, the external
shell rotating at a constant angular velocity with respect to the inner shell.
Here I show that this picture is not quite right and that a more careful look
leads us to one in which both shells rotates at different mean angular
velocities and with a forward-backward sequence of movements relative to each
other. In this way what was supposed to be the principal factor against gravity
influence becomes the main favourable one.


title: The Epidemics of Corruption

abstract:
  We study corruption as a generalized epidemic process on the graph of social
relationships. The main difference to classical epidemic processes is the
strong nonlinear dependence of the transmission probability on the local
density of corruption and the mean field influence of the overall corruption in
the society. Network clustering and the degree-degree correlation play an
essential role in corruption dynamics. We discuss phase transitions, the
influence of the graph structure and the implications for epidemic control.
Structural and dynamical arguments are given why strongly hierarchically
organized societies like systems with dictatorial tendency are more vulnerable
to corruption than democracies. A similar type of modelling can be applied to
other social contagion spreading processes like opinion formation, doping
usage, social disorders or innovation dynamics.


title: Automated Trading Systems: Developed and Emerging Capital Markets

abstract:
  Automated trading systems on developed and emerging capital markets are
studied in this paper. The standard for developed market is automated trading
system with 40-days simple moving average. We tested it for the index SIX
Industrial for 1000 and 730 trading days of the slovak emerging capital market.
The Buy and Hold trading system was 7.80 times more profitable than this etalon
trading system for active trading. Taking of profitable standard trading system
from a developed capital market does not lead to optimal results on the
emerging capital markets. We then studied optimized standard trading system
based on the simple moving average. The parameter of optimization was the
number of weeks. An optimal system was that with 5 weeks. This trading system
has some of its characteristics comparable with the etalon trading system on
the NYSE Composite Index. The emerging market is more risky than the developed
market. The profit on the emerging market is also higher. The range of
optimized system parameter is quite robust. Observed was increase of number of
trades in the range from the 21 weeks to the 25 weeks. This indicates creation
of a new optimal middle range trading system. Results of testing for liquid
shares are quantitatively similar.


title:
A physical model for aftershocks triggered by dislocation on a
  rectangular fault

abstract:
  We find the static displacement, stress, strain and the modified Columb
failure stress produced in an elastic medium by a finite size rectangular fault
after its dislocation with uniform stress drop but a non uniform dislocation on
the source. The time-dependent rate of triggered earthquakes is estimated by a
rate-state model applied to a uniformly distributed population of faults whose
equilibrium is perturbated by a stress change caused only by the first
dislocation. The rate of triggered events in our simulations is exponentially
proportional to the stress change, but the time at which the maximum rate
begins to decrease is variable from fractions of hour for positive stress
changes of the order of some MPa, up to more than a year for smaller stress
changes. As a consequence, the final number of triggered events is proportional
to the stress change. The model predicts that the total number of events
triggered on a plane containing the fault is proportional to the 2/3 power of
the seismic moment. Indeed, the total number of aftershocks produced on the
fault plane scales in magnitude as 10^{M}. Including the negative contribution
of the stress drop inside the source, we observe that the number of events
inhibited on the fault is, at long term, nearly identical to the number of
those induced outside, representing a sort of conservative natural rule.
Considering its behaviour in time, our model doesn't completely match the
popular Omori law; in fact it has been shown that the seismicity induced
closely to the fault edges is intense but of short duration, while that
expected at large distances (up to some tens times the fault dimensions)
exhibits a much slower decay.


title: No need to blur the picture

abstract:
  A formalism specifying efficient, "emergent" descriptions of experimental
systems is developed. It does not depend on an a priori assumption of limited
available data.


title:
Reconstructed standard model of cosmology in the Earth-related
  coordinate system

abstract:
  In the Earth-related coordinate system, we reconstruct the standard model of
cosmology based on the assumption of the cosmological principle and the perfect
gas (or fluid). We exactly solve Einstein's field equation involved. The
solution consists of three parts respectively on the line element for
space-time of the Universe, the value for the cosmological constant and the
equation of state for the matter of the Universe.


title: Formula for red-shift of light signals coming from distant galaxies

abstract:
  Relying on the obtained results in Rev.[1](physics/0505035), we derive the
formula relating the red-shift of light signals coming from distant galaxies to
the distance of these galaxies from us and the time of detecting of these light
signals. The red-shift coefficient, instead of the Hubble parameter, is
introduced. It varies with time and positive at all times. Its nowadays value
equals the Hubble parameter. It increases forever as time is running from the
past to the future. The derived formula enables us to estimate the nowadays
increasing rate of the red-shift coefficient, which is nothing but the nowadays
value of the "acceleration of the expansion of the Universe".


title: Forecast of the Chemical Aging and Relevant Color Changes in Painting

abstract:
  The article describes the potential application of thermodynamic simulation
to forecast chemical aging and relevant color changes in painting. Qualitative
and numerical results were obtained by applying the method to various mixtures
of pigments without and with atmospheric components. The results were compared
to the legendary recommendations on incompatible pigment mixtures with about an
80 percent match regarding potential color changes in the aged mixtures.
Results for the cadmium yellow-lead white and cadmium lemon-emerald green
mixtures are illustrated by pictures, gradually showing color changes caused by
the aging. The method of thermodynamic simulation can be a powerful tool to
investigate old masterpieces, in developing new materials, and to forecast some
aspects of the aging of real masterpieces.


title:
Comment on ``Torque or no torque? Simple charged particle motion
  observed in different inertial frames,'' by J. D. Jackson [Am. J. Phys. 72
  (12), 1484-1487 (2004)]

abstract:
  In this paper it is shown that the real cause of the apparent electrodynamic
paradox discussed by Jackson [J. D. Jackson, Am. J. Phys. 72, 1484 (2004)] is
the use of three-dimensional (3D) quantities E, B, F, L, N, .. . When 4D
geometric quantities are used then there is no paradox and the principle of
relativity is naturally satisfied.


title: Continuous loading of an electrostatic trap for polar molecules

abstract:
  A continuously operated electrostatic trap for polar molecules is
demonstrated. The trap has a volume of ~0.6 cm^3 and holds molecules with a
positive Stark shift. With deuterated ammonia from a quadrupole velocity
filter, a trap density of ~10^8/cm^3 is achieved with an average lifetime of
130 ms and a motional temperature of ~300 mK. The trap offers good starting
conditions for high-precision measurements, and can be used as a first stage in
cooling schemes for molecules and as a "reaction vessel" in cold chemistry.


title: Physics of Binary Information

abstract:
  Basic concepts of theoretical particle physics, including quantum mechanics
and Poincar\'e invariance, the leptonic mass spectrum and the proton mass, can
be derived, without reference to first principles, from intrinsic properties of
the simplest elements of information represented by binary data. What we
comprehend as physical reality is, therefore, a reflection of mathematically
determined logical structures, built from elements of binary data.


title: Where and how does it happen ?

abstract:
  It has for ages been a rather constant feature of thinking in science to take
it for granted that the respective thinking happens in realms which are totally
outside and independent of all the other phenomena that constitute the objects
of such thinking. The imposition of this divide on two levels may conflict with
basic assumptions of Newtonian and Einsteinian mechanics, as well as with those
in Quantum Mechanics. It also raises the question whether the realms in which
thinking happens have no any other connection with the realms science deals
with, except to host and allow scientific thinking.


title: Zeno meets modern science

abstract:
  ``No one has ever touched Zeno without refuting him''. We will not refute
Zeno in this paper. Instead we review some unexpected encounters of Zeno with
modern science. The paper begins with a brief biography of Zeno of Elea
followed by his famous paradoxes of motion. Reflections on continuity of space
and time lead us to Banach and Tarski and to their celebrated paradox, which is
in fact not a paradox at all but a strict mathematical theorem, although very
counterintuitive. Quantum mechanics brings another flavour in Zeno paradoxes.
Quantum Zeno and anti-Zeno effects are really paradoxical but now experimental
facts. Then we discuss supertasks and bifurcated supertasks. The concept of
localization leads us to Newton and Wigner and to interesting phenomenon of
quantum revivals. At last we note that the paradoxical idea of timeless
universe, defended by Zeno and Parmenides at ancient times, is still alive in
quantum gravity. The list of references that follows is necessarily incomplete
but we hope it will assist interested reader to fill in details.


title: Modeling heavy ion ionization loss in the MARS15 code

abstract:
  The needs of various accelerator and space projects stimulated recent
developments to the MARS Monte Carlo code. One of the essential parts of those
is heavy ion ionization energy loss. This paper describes an implementation of
several corrections to dE/dx in order to take into account the deviations from
the Bethe theory at low and high energies as well as the effect of a finite
nuclear size at ultra-relativistic energies. Special attention is paid to the
transition energy region where the onset of the effect of a finite nuclear size
is observed. Comparisons with experimental data and NIST data are presented.


title: Breaking van der Waals molecules with magnetic fields

abstract:
  It is demonstrated that weakly bound van der Waals complexes can dissociate
in a magnetic field through coupling between the Zeeman levels. The Zeeman
predissociation process is shown to be efficient and it can be controlled by
external magnetic fields.


title: An omission in Special Relativity

abstract:
  In Special Relativity there are infinitely many equivalence classes of frames
of reference. In each such class every two frames of reference move uniformly
with respect to one another. It appears that the following questions have never
been asked : 1) In which of such equivalence classes of frames of reference is
Special Relativity supposed to hold ? 2) How can we identify such a class, and
do so theoretically or empirically ?


title: Free-Space Antenna Field/Pattern Retrieval in Reverberation Environments

abstract:
  Simple algorithms for retrieving free-space antenna field or directivity
patterns from complex (field) or real (intensity) measurements taken in ideal
reverberation environments are introduced and discussed.


title: Analyzing money distributions in `ideal gas' models of markets

abstract:
  We analyze an ideal gas like models of a trading market. We propose a new fit
for the money distribution in the fixed or uniform saving market. For the
marketwith quenched random saving factors for its agents we show that the
steady state income ($m$) distribution $P(m)$ in the model has a power law tail
with Pareto index $\nu$ exactly equal to unity, confirming the earlier
numerical studies on this model. We analyze the distribution of mutual money
difference and also develop a master equation for the time development of
$P(m)$. Precise solutions are then obtained in some special cases.


title:
Electric Quadrupole Moment of a Hydrogenlike Ion in $s$ and $p_{1/2}$
  States

abstract:
  Relativistic formulas for the electric quadrupole moment of a hydrogenlike
atom, induced by the hyperfine interaction, are derived for $ns_{1/2}$ and
$np_{1/2}$ states. Both the magnetic dipole and electric quadrupole hyperfine
interactions are taken into account. The formulas are valid for ions with
arbitrary nuclear charge and spin. The induced quadrupole moment is compared
with the nuclear quadrupole moment for a wide range of hydrogenlike ions.


title: Live and Dead Nodes

abstract:
  In this paper, we explore the consequences of a distinction between `live'
and `dead' network nodes; `live' nodes are able to acquire new links whereas
`dead' nodes are static. We develop an analytically soluble growing network
model incorporating this distinction and show that it can provide a
quantitative description of the empirical network composed of citations and
references (in- and out-links) between papers (nodes) in the SPIRES database of
scientific papers in high energy physics. We also demonstrate that the death
mechanism alone can result in power law degree distributions for the resulting
network.


title:
A network-based threshold model for the spreading of fads in society and
  markets

abstract:
  We investigate the behavior of a threshold model for the spreading of fads
and similar phenomena in society. The model is giving the fad dynamics and is
intended to be confined to an underlying network structure. We investigate the
whole parameter space of the fad dynamics on three types of network models. The
dynamics we discover is rich and highly dependent on the underlying network
structure. For some range of the parameter space, for all types of substrate
networks, there are a great variety of sizes and life-lengths of the fads --
what one see in real-world social and economical systems.


title: Coherent population trapping in ruby crystal at room temperature

abstract:
  Observation of coherent population trapping (CPT) at ground-state Zeeman
sublevels of $Cr^{3+}$-ion in ruby is reported. The experiments are performed
at room temperature by using both nanosecond optical pulses and nanosecond
trains of ultrashort pulses. In both cases sharp drops in the resonantly
induced fluorescence are detected as the external magnetic field is varied.
Theoretical analysis of CPT in a transient regime due to pulsed action of
optical pulses is presented.


title: Microfluidic capturing-dynamics of paramagnetic bead suspensions

abstract:
  We study theoretically the capturing of paramagnetic beads by a magnetic
field gradient in a microfluidic channel treating the beads as a continuum.
Bead motion is affected by both fluidic and magnetic forces. The transfer of
momentum from beads to the fluid creates an effective bead-bead interaction
that greatly aids capturing. We demonstrate that for a given inlet flow speed a
critical density of beads exists above which complete capturing takes place.


title:
A Note About the Simulation Programs for Heat and Molecular Physics
  Laboratory

abstract:
  In order to understand the physics phenomea on the fundamental aspects, the
software simulations are a good exercise to succed in this way. Some work of
heat transport and molecular physics laboratory are studied in a comparative
mode experiments and software applications. The main ojbects structure ans some
program interfaces are presented.


title:
Numerical study of high frequency asymptotics of the symbol of the
  Dirichlet-to-Neumann operator in 2D diffraction problems

abstract:
  A high-frequency asymptotics of the symbol of the Dirichlet-to-Neumann map,
treated as a periodic pseudodifferential operator, in 2D diffraction problems
is discussed. Numerical results support a conjecture on a universal limit shape
of the symbol.


title: Two photon ionization of condensate atoms

abstract:
  The efficient photoionization of a Bose-Einstein condensate requires the
creation of ions with the smallest possible transfer of atoms from the
condensate into the thermal phase. The spontaneous decay from excited states
into atomic states with momentum different from the initial one should be
reduced. We investigate theoretically the two-photon ionization of a rubidium
condensate using near resonant excitation to the 6P state and second photon at
421 nm or 1002 nm into the continuum. Different ionization schemes with
coherent control of the first excitation and reduction of the spontaneous decay
are presented.


title:
Hydrodynamic interactions of spherical particles in suspensions confined
  between two planar walls

abstract:
  Hydrodynamic interactions in a suspension of spherical particles confined
between two parallel planar walls are studied under creeping-flow conditions.
The many-particle friction matrix in this system is evaluated using our novel
numerical algorithm based on transformations between Cartesian and spherical
representations of Stokes flow. The Cartesian representation is used to
describe the interaction of the fluid with the walls and the spherical
representation is used to describe the interaction with the particles. The
transformations between these two representations are given in a closed form,
which allows us to evaluate the coefficients in linear equations for the
induced-force multipoles on particle surfaces. The friction matrix is obtained
from these equations, supplemented with the superposition lubrication
corrections. We have used our algorithm to evaluate the friction matrix for a
single sphere, a pair of spheres, and for linear chains of spheres. The
friction matrix exhibits a crossover from a quasi-two-dimensional behavior (for
systems with small wall separation H) to the three-dimensional behavior (when
the distance H is much larger than the interparticle distance L). The crossover
is especially pronounced for a long chain moving in the direction normal to its
orientation and parallel to the walls. In this configuration, a large pressure
buildup occurs in front of the chain for small values of the gapwidth H, which
results in a large hydrodynamic friction force. A standard wall superposition
approximation does not capture this behavior.


title:
Levy stable distribution and [0,2] power law dependence of acoustic
  absorption on frequency

abstract:
  The absorption of acoustic wave propagation in a broad variety of lossy media
is characterized by an empirical power law function of frequency, w^y. It has
long been noted that exponent y ranges from 0 to 2 for diverse media. Recently,
the present author developed a fractional Laplacian wave equation to accurately
model the power law dissipation, which can be further reduced to the fractional
Laplacian diffusion equation. The latter is known underlying the Levy stable
distribution theory. Consequently, the parameters y is found to be the Levy
stability index, which is known bounded within 0<y\le2. This finding first
provides a theoretical explanation of empirical observations 0<y<=2.
Statistically, the frequency-dependent absorption can thus be understood a Levy
stable process, where the parameter y describes the fractal nature of
attenuative media.


title: Rotationnal and translational waves in a bowed string

abstract:
  We measure and compare the rotational and transverse velocity of a bowed
string. When bowed by an experienced player, the torsional motion is
phase-locked to the transverse waves, producing highly periodic motion. The
spectrum of the torsional motion includes the fundamental and harmonics of the
transverse wave, with strong formants at the natural frequencies of the
torsional standing waves in the whole string. Volunteers with no experience on
bowed string instruments, however, often produced non-periodic motion. We
present sound files of both the transverse and torsional velocity signals of
well-bowed strings. The torsional signal has not only the pitch of the
transverse signal, but it sounds recognisably like a bowed string, probably
because of its rich harmonic structure and the transients and amplitude
envelope produced by bowing.


title: Torsional waves in a bowed string

abstract:
  Bowing a string with a non-zero radius exerts a torque, which excites
torsional waves. In general, torsional standing waves have higher fundamental
frequencies than do transverse standing waves, and there is generally no
harmonic relationship between them. Although torsional waves have little direct
acoustic effect, the motion of the bow-string contact depends on the sum of the
transverse speed v of the string plus the radius times the angular velocity
(rw) . Consequently, in some bowing regimes, torsional waves could introduce
non-periodicity or jitter to the transverse wave. The ear is sensitive to
jitter so, while quite small amounts of jitter are important in the sounds of
(real) bowed strings, modest amounts of jitter can be perceived as unpleasant
or unmusical. It follows that, for a well bowed string, aperiodicities produced
in the transverse motion by torsional waves (and other effects) must be small.
Is this because the torsional waves are of small amplitude or because of strong
coupling between the torsional and transverse waves? We measure the torsional
and transverse motion for a string bowed by an experienced player over a range
of tunings. The peaks in (rw), which occur near the start and end of the stick
phase in which the bow and string move together, are only several times smaller
than v during this phase.


title: Optimally Controlled Field-Free Orientation of the Kicked Molecule

abstract:
  Efficient and long-lived field-free molecular orientation is achieved using
only two kicks appropriately delayed in time. The understanding of the
mechanism rests upon a molecular target state providing the best efficiency
versus persistence compromise. An optimal control scheme is referred to for
fixing the free parameters (amplitudes and the time delay between them). The
limited number of kicks, the robustness and the transposability to different
molecular systems advocate in favor of the process, when considering its
experimental feasibility.


title: Plasmonic bandgaps and Trapped Plasmons on Nanostructured Metal Surfaces

abstract:
  Nanostructured metal surfaces comprised of periodically arranged spherical
voids are grown by electrochemical deposition through a self-assembled
template. Detailed measurements of the angle- and orientation-dependent
reflectivity reveal the spectral dispersion, from which we identify the
presence of both delocalized Bragg- and localized Mie-plasmons. These couple
strongly producing bonding and anti-bonding mixed plasmons with anomalous
dispersion properties. Appropriate plasmon engineering of the void morphology
selects the plasmon spatial and spectral positions, allowing these plasmonic
crystal films to be optimised for a wide range of sensing applications.


title: Bistable light detectors with nonlinear waveguide arrays

abstract:
  Bistability induced by nonlinear Kerr effect in arrays of coupled waveguides
is studied and shown to be a means to conceive light detectors that switch
under excitation by a weak signal. The detector is obtained by coupling two
single 1D waveguide to an array of coupled waveguides with adjusted indices and
coupling. The process is understood by analytical description in the
conservative and continuous case and illustrated by numerical simulations of
the model with attenuation.

categories: physics.optics cond-mat.stat-mech nlin.PS physics.class-ph


title: Foundations of a Universal Theory of Relativity

abstract:
  Earlier, we had presented \cite{heuristic} heuristic arguments to show that a
{\em natural unification} of the ideas of the quantum theory and those
underlying the general principle of relativity is achievable by way of the
measure theory and the theory of dynamical systems. Here, in Part I, we provide
the complete physical foundations for this, to be called, the {\em Universal
Theory of Relativity}. Newton's theory and the special theory of relativity
arise, situationally, in this Universal Relativity. Explanations of quantum
indeterminacy are also shown to arise in it. Part II provides its mathematical
foundations. One experimental test is also discussed before concluding remarks.


title: The Community Structure of Econophysicist Collaboration Networks

abstract:
  This paper uses a database of collaboration recording between Econophysics
Scientists to study the community structure of this collaboration network,
which with a single type of vertex and a type of undirected, weighted edge.
Hierarchical clustering and the algorithm of Girvan and Newman are presented to
analyze the data. And it emphasizes the influence of the weight to results of
communities by comparing the different results obtained in different weights. A
function D is proposed to distinguish the difference between above results. At
last the paper also gives explanation to the results and discussion about
community structure.


title:
LevelScheme: A level scheme drawing and scientific figure preparation
  system for Mathematica

abstract:
  LevelScheme is a scientific figure preparation system for Mathematica. The
main emphasis is upon the construction of level schemes, or level energy
diagrams, as used in nuclear, atomic, molecular, and hadronic physics.
LevelScheme also provides a general infrastructure for the preparation of
publication-quality figures, including support for multipanel and inset
plotting, customizable tick mark generation, and various drawing and labeling
tasks. Coupled with Mathematica's plotting functions and powerful programming
language, LevelScheme provides a flexible system for the creation of figures
combining diagrams, mathematical plots, and data plots.

categories: physics.comp-ph nucl-ex nucl-th physics.atom-ph


title: Path integrals and symmetry breaking for optimal control theory

abstract:
  This paper considers linear-quadratic control of a non-linear dynamical
system subject to arbitrary cost. I show that for this class of stochastic
control problems the non-linear Hamilton-Jacobi-Bellman equation can be
transformed into a linear equation. The transformation is similar to the
transformation used to relate the classical Hamilton-Jacobi equation to the
Schr\"odinger equation. As a result of the linearity, the usual backward
computation can be replaced by a forward diffusion process, that can be
computed by stochastic integration or by the evaluation of a path integral. It
is shown, how in the deterministic limit the PMP formalism is recovered. The
significance of the path integral approach is that it forms the basis for a
number of efficient computational methods, such as MC sampling, the Laplace
approximation and the variational approximation. We show the effectiveness of
the first two methods in number of examples. Examples are given that show the
qualitative difference between stochastic and deterministic control and the
occurrence of symmetry breaking as a function of the noise.


title: Elliptically Symmetric Polarized Beams

abstract:
  We study the free-propagation features of an optical field endowed with a
non-uniform polarization pattern with elliptical symmetry. The fields derived
in this way are called Elliptically Symmetric Polarized Beams (ESPB for short).
Some properties of these fields are analysed. Moreover, it is shown how it is
possible to obtain such light beams by applying the results to Bessel-Gauss
beams.


title: A Full Review of the Theory of Electromagnetism

abstract:
  We will provide detailed arguments showing that the set of Maxwell equations,
and the corresponding wave equations, do not properly describe the evolution of
electromagnetic wave-fronts. We propose a nonlinear corrected version that is
proven to be far more appropriate for the modellization of electromagnetic
phenomena. The suitability of this approach will soon be evident to the reader,
through a sequence of astonishing congruences, making the model as elegant as
Maxwell's, but with increased chances of development. Actually, the new set of
equations will allow us to explain many open questions, and find links between
electromagnetism and other theories that have been searched for a long time, or
not even imagined.


title:
A Simple General Solution for Maximal Horizontal Range of Projectile
  Motion

abstract:
  A convenient change of variables in the problem of maximizing the horizontal
range of the projectile motion, with an arbitrary initial vertical position of
the projectile, provides a simple, straightforward solution.


title: Idealized Slab Plasma approach for the study of Warm Dense Matter

abstract:
  Recently, warm dense matter (WDM) has emerged as an interdisciplinary field
that draws increasing interest in plasma physics, condensed matter physics,
high pressure science, astrophysics, inertial confinement fusion, as well as
materials science under extreme conditions. To allow the study of well-defined
WDM states, we have introduced the concept of idealized-slab plasmas that can
be realized in the laboratory via (i) the isochoric heating of a solid and (ii)
the propagation of a shock wave in a solid. The application of this concept
provides new means for probing the dynamic conductivity, equation of state,
ionization and opacity. These approaches are presented here using results
derived from first-principles (density-functional type) theory, Thomas-Fermi
type theory, and numerical simulations.

categories: physics.plasm-ph astro-ph cond-mat.mtrl-sci physics.gen-ph


title:
How does Europe Make Its Mind Up? Connections, cliques, and
  compatibility between countries in the Eurovision Song Contest

abstract:
  We investigate the complex relationships between countries in the Eurovision
Song Contest, by recasting past voting data in terms of a dynamical network.
Despite the British tendency to feel distant from Europe, our analysis shows
that the U.K. is remarkably compatible, or 'in tune', with other European
countries. Equally surprising is our finding that some other core countries,
most notably France, are significantly 'out of tune' with the rest of Europe.
In addition, our analysis enables us to confirm a widely-held belief that there
are unofficial cliques of countries -- however these cliques are not always the
expected ones, nor can their existence be explained solely on the grounds of
geographical proximity. The complexity in this system emerges via the group
'self-assessment' process, and in the absence of any central controller. One
might therefore speculate that such complexity is representative of many
real-world situations in which groups of 'agents' establish their own
inter-relationships and hence ultimately decide their own fate. Possible
examples include groups of individuals, societies, political groups or even
governments.


title: A variance-minimization scheme for optimizing Jastrow factors

abstract:
  We describe a new scheme for optimizing many-electron trial wave functions by
minimizing the unreweighted variance of the energy using stochastic integration
and correlated-sampling techniques. The scheme is restricted to parameters that
are linear in the exponent of a Jastrow correlation factor, which are the most
important parameters in the wave functions we use. The scheme is highly
efficient and allows us to investigate the parameter space more closely than
has been possible before. We search for multiple minima of the variance in the
parameter space and compare the wave functions obtained using reweighted and
unreweighted variance minimization.


title:
Measurements of the bulk and interfacial velocity profiles in
  oscillating Newtonian and Maxwellian fluids

abstract:
  We present the dynamic velocity profiles of a Newtonian fluid (glycerol) and
a viscoelastic Maxwell fluid (CPyCl/NaSal in water) driven by an oscillating
pressure gradient in a vertical cylindrical pipe. The frequency range explored
has been chosen to include the first three resonance peaks of the dynamic
permeability of the viscoelastic fluid / pipe system. Three different optical
measurement techniques have been employed. Laser Doppler Anemometry has been
used to measure the magnitude of the velocity at the centre of the liquid
column. Particle Image Velocimetry and Optical Deflectometry are used to
determine the velocity profiles at the bulk of the liquid column and at the
liquid--air interface respectively. The velocity measurements in the bulk are
in good agreement with the theoretical predictions of a linear theory. The
results, however, show dramatic differences in the dynamic behaviour of
Newtonian and viscoelastic fluids, and demonstrate the importance of resonance
phenomena in viscoelastic fluid flows, biofluids in particular, in confined
geometries.


title: The bulk of the stock market correlation matrix is not pure noise

abstract:
  We analyse the structure of the distribution of eigenvalues of the stock
market correlation matrix with increasing length of the time series
representing the price changes. We use 100 highly-capitalized stocks from the
American market and relate result to the corresponding ensemble of Wishart
random matrices. It turns out that systematically more eigenvalues stay beyond
the borders prescribed by this variant of the Random Matrix Theory (RMT). This
may indicate that even the bulk of the spectrum of the stock market correlation
matrix carries some sort of correlations that are masked by a measurement noise
when the time series used to construct the matrix are short. We also study some
other characteristics of the "noisy" eigensignals, like their return
distributions, temporal correlations or their multifractal spectra and the
results support the above conclusions.


title: Complex patterns and tip effect evolution

abstract:
  We studied the formation of complex patterns using a variational principle
and a standard energy functional. These patterns evolve by letting the system
to search for the optimal configuration of a high conductivity channel, that in
one dimension is equivalent to tip effect evolution (evolution towards regions
of high electric field).


title: Phase Contrast technique: a broader approach

abstract:
  The treatment found on most general optics textbooks related to the phase
contrast technique imposes limitations on the filter phase and object phase
variations in order to mathematically explain it in a simple manner. We
consider that this simplified treatment can be misleading in terms of the
concept the student may develop and also about the potential applications of
the phase contrast technique. In this paper we describe a broader and yet
simple explanation of the phase contrast process, creating a parallelism
between optical image processing and interferometry.


title: Quantum Gauge Theory Amplitude Solutions

abstract:
  The $n$-point amplitudes of gauge and gravity theory are given as a series in
the coupling. The recursive derivative expansion is used to find all of the
coupling coefficients. Initial conditions to any bare Lagrangian, or of an
improved action, are used to compute quantum amplitudes.


title:
Plasmon mechanism of light transmission through a metal film or a plasma
  layer

abstract:
  It is shown that a smooth metal film (or a plasma layer) can be made
transparent for an electromagnetic wave when two identical subwavelength
diffraction gratings are placed on both sides of the film. The electromagnetic
wave transmission through the metal film is caused by excitation of evanescent
surface waves (plasmons) and their transformation into propagating waves at the
gratings. A model which is developed analytically shows that the problem of the
wave transmission is physically equivalent to the problem of excitation of two
coupled resonators of evanescent waves which are formed at the two film
surfaces.


title:
Fundamental Factors versus Herding in the 2000-2005 US Stock Market and
  Prediction

abstract:
  We present a general methodology to incorporate fundamental economic factors
to our previous theory of herding to describe bubbles and antibubbles. We start
from the strong form of Rational Expectation and derive the general method to
incorporate factors in addition to the log-periodic power law (LPPL) signature
of herding developed in ours and others' works. These factors include interest
rate, interest spread, historical volatility, implied volatility and exchange
rates. Standard statistical AIC and Wilks tests allow us to compare the
explanatory power of the different proposed factor models. We find that the
historical volatility played the key role before August of 2002. Around October
2002, the interest rate dominated. In the first six months of 2003, the foreign
exchange rate became the key factor. Since the end of 2003, all factors have
played an increasingly large role. However, the most surprising result is that
the best model is the second-order LPPL without any factor. We thus present a
scenario for the future evolution of the US stock market based on the
extrapolation of the fit of the second-order LPPL formula, which suggests that
herding is still the dominating force and that the unraveling of the US stock
market antibubble since 2000 is still qualitatively similar to (but
quantitatively different from) the Japanese Nikkei case after 1990.


title: Towards Experimental Tests of Quantum Effects in Cytoskeletal Proteins

abstract:
  It has become increasingly evident that fabrication of novel biomaterials
through molecular self-assembly is going to play a significant role in material
science and possibly the information technology of the future. Tubulin,
microtubules (MTs) and the cytoskeleton are dynamic, self-assembling systems
and we asked whether their structure and function contain the clues on how to
fabricate biomolecular information processing devices.
  Here we review our neurobiological studies of transgenic Drosophila that
strongly suggest the microtubular cytoskeleton is near the 'front lines' of
intracellular information manipulation and storage. We also establish that
spectroscopic techniques such as refractometry, surface plasmon resonance
sensing and dielectric spectroscopy, coupled with molecular dynamic simulations
and (quantum) electrodynamic analytical theory are useful tools in the study of
the electrodynamic and possible quantum effects in cytoskeletal proteins.
  Implicit in our driving question is the possibility that if tubulin and MTs
can indeed be cast as the basis of a classical or quantum computer, then
perhaps nature has already done so and tubulin and MTs already play such a role
in living neural and other cells. If quantum mechanics is found to be important
in cellular function (through its involvement in proteins) it is natural to ask
whether there are indeed quantum effects pertinent to consciousness. We
conclude this work by suggesting a number of ways towards experimentally
testing this "Quantum Consciousness Idea" (QCI), directly at the protein level.


title:
Testing the time dependence of the fundamental constants in the spectra
  of multicharged ions

abstract:
  A new method for measuring a possible time dependence of the fine-structure
constant ($\alpha$) is proposed. The method is based on the level-crossing in
two-electron highly-charged ions facilitating resonance laser measurements of
the distance between the levels at the point of crossing. This provides an
enhancement factor of about $10^{3}$ in Helium-like Europium and thus reduces
the requirements for the relative accuracy of resonance laser measurements at
about $10^{-12}$.


title:
Simultaneous Amplitude and Phase Measurement for Periodic Optical
  Signals Using Time-Resolved Optical Filtering

abstract:
  Time-resolved optical filtering (TROF) measures the spectrogram or sonogram
by a fast photodiode followed a tunable narrowband optical filter. For periodic
signal and to match the sonogram, numerical TROF algorithm is used to find the
original complex electric field or equivalently both the amplitude and phase.
For phase-modulated optical signals, the TROF algorithm is initiated using the
craters and ridges of the sonogram.


title: Radar scattering by aggregate snowflakes

abstract:
  The radar scattering properties of realistic aggregate snowflakes have been
calculated using the Rayleigh-Gans theory. We find that the effect of the
snowflake geometry on the scattering may be described in terms of a single
universal function, which depends only on the overall shape of the aggregate
and not the geometry or size of the pristine ice crystals which compose the
flake. This function is well approximated by a simple analytic expression at
small sizes; for larger snowflakes we fit a curve to our numerical data. We
then demonstrate how this allows a characteristic snowflake radius to be
derived from dual-wavelength radar measurements without knowledge of the
pristine crystal size or habit, while at the same time showing that this detail
is crucial to using such data to estimate ice water content. We also show that
the `effective radius', characterising the ratio of particle volume to
projected area, cannot be inferred from dual-wavelength radar data for
aggregates. Finally, we consider the errors involved in approximating
snowflakes by `air-ice spheres', and show that for small enough aggregates the
predicted dual wavelength ratio typically agrees to within a few percent,
provided some care is taken in choosing the radius of the sphere and the
dielectric constant of the air-ice mixture; at larger sizes the radar becomes
more sensitive to particle shape, and the errors associated with the sphere
model are found to increase accordingly.


title: Dynamics and thermodynamics of axisymmetric flows: I. Theory

abstract:
  We develop new variational principles to study stability and equilibrium of
axisymmetric flows. We show that there is an infinite number of steady state
solutions. We show that these steady states maximize a (non-universal)
$H$-function. We derive relaxation equations which can be used as numerical
algorithm to construct stable stationary solutions of axisymmetric flows. In a
second part, we develop a thermodynamical approach to the equilibrium states at
some fixed coarse-grained scale. We show that the resulting distribution can be
divided in a universal part coming from the conservation of robust invariants
and one non-universal determined by the initial conditions through the fragile
invariants (for freely evolving systems) or by a prior distribution encoding
non-ideal effects such as viscosity, small-scale forcing and dissipation (for
forced systems). Finally, we derive a parameterization of inviscid mixing to
describe the dynamics of the system at the coarse-grained scale.


title: Ground Control to Niels Bohr: Exploring Outer Space with Atomic Physics

abstract:
  We provided an introduction to transition state theory and the connections it
provides between atomic and celestial physics. We include brief discussions of
historical background, recent applications in space mission design, and current
research efforts.

categories: physics.pop-ph math.DS nlin.CD physics.atom-ph


title:
Social Behaviour of Agents: Capital Markets and Their Small
  Perturbations

abstract:
  We study social behaviour of agents on capital markets when these are
perturbed by small perturbations. We use the mean field method. Social
behaviour of agents on capital markets is described: volatility of the market,
aversion constant and equilibrium states are discussed. Relaxation behaviour of
agents on the capital market is studied. Equation of motion for the agent
average number is of the relaxation type. Development of the group of agents in
the states corresponding to minimum of the aim function is either linear either
exponentially damped. There exist characteristic volatility constants $ V_{c3}
$ and $ V_{c3} $. The constant b of verification of information contribution to
the aversion constant A and the $ A_{0} $ constant of aversion are
distinguishing three types of dependencies of the minimum of the aim function
on the expected volatility EV and on the expected returns E. Arbitrage trades
and group forces lead the group into the equilibrium state. Verification of
information intensity influences return back to the equilibrium state. The
linear in time damping to the equilibrium state is characterized with the
characteristic time $ T_{3}$ and $ T_{6} $, the exponential with a
characteristic time $ \tau $. Their dependence on the expected volatility, on
the expected profit and characteristics of agents is discussed.


title: Fifteen Minutes of Fame: The Dynamics of Information Access on the Web

abstract:
  While current studies on complex networks focus on systems that change
relatively slowly in time, the structure of the most visited regions of the Web
is altered at the timescale from hours to days. Here we investigate the
dynamics of visitation of a major news portal, representing the prototype for
such a rapidly evolving network. The nodes of the network can be classified
into stable nodes, that form the time independent skeleton of the portal, and
news documents. The visitation of the two node classes are markedly different,
the skeleton acquiring visits at a constant rate, while a news document's
visitation peaking after a few hours. We find that the visitation pattern of a
news document decays as a power law, in contrast with the exponential
prediction provided by simple models of site visitation. This is rooted in the
inhomogeneous nature of the browsing pattern characterizing individual users:
the time interval between consecutive visits by the same user to the site
follows a power law distribution, in contrast with the exponential expected for
Poisson processes. We show that the exponent characterizing the individual
user's browsing patterns determines the power-law decay in a document's
visitation. Finally, our results document the fleeting quality of news and
events: while fifteen minutes of fame is still an exaggeration in the online
media, we find that access to most news items significantly decays after 36
hours of posting.


title: Aesthetic complexity

abstract:
  Aesthetics, among other criteria, can be statistically examined in terms of
the complexity required for creating and decrypting a work of art. We propose
three laws of aesthetic complexity. According to the first law of aesthetic
complexity, too condensed encoding makes a decryption of a work of art
impossible and is perceived as chaotic by the untrained mind, whereas too
regular structures are perceived as monotonous, too orderly and not very
stimulating. Thus a necessary condition for an artistic form or design to
appear appealing is its complexity to lie within a bracket between monotony and
chaos. According to the second law of aesthetic complexity, due to human
predisposition, this bracket is invariably based on natural forms; with rather
limited plasticity. The third law of aesthetic complexity states that aesthetic
complexity trends are dominated by the available resources, and thus also by
cost and scarcity.


title: Nuclear spin gyroscope based on an atomic co-magnetometer

abstract:
  We describe a nuclear spin gyroscope based on an alkali-metal-noble-gas
co-magnetometer. An optically pumped alkali-metal vapor is used to polarize the
noble gas atoms and detect their gyroscopic precession. Spin precession due to
magnetic fields as well as their gradients and transients can be cancelled in
this arrangement. The sensitivity is enhanced by using a high-density
alkali-metal vapor in a spin-exchange relaxation free (SERF) regime. With a
K-3He co-magnetometer we demonstrate rotation sensitivity of 5 10^(-7)
rad/sec/Hz^(1/2). The rotation signal can be increased by a factor of 10 using
21Ne due to its smaller magnetic moment and the fundamental rotation
sensitivity limit for a 21Ne gyroscope with a 10 cm^3 measurement volume is
about 2 10^(-10) rad/sec/Hz^(1/2).


title: Why Einstein (Had I been born in 1844!)?

abstract:
  In his monumental discoveries, the driving force for Einstein was, I believe,
consistency of concept and principle rather than conflict with experiment. In
this spirit, I would like to look at the journey from the classical to the
relativistic world as a simple and direct exercise first in recognition of
universal character of universal entities and then carrying out the
universalization. By this process not only the relativistic world follows most
naturally but I would like to conjecture that if Einstein were born in 1844 (or
had I been born in 1844 and had followed this line of thought as I do now!) it
would have in fact been predicted including existence of a wave with universal
constant velocity. That would have indeed been not only the greatest but most
amazing and remarkable feat of human thought.
  Beating further on the same track of principle and concept driven ideas, we
ponder over to see beyond Einstein, and ask the questions: in how many
dimensions does gravity live, how many basic forces are there in nature and
what are the basic building blocks of space-time?

categories: physics.gen-ph astro-ph gr-qc physics.hist-ph


title:
Teaching and learning physics: A model for coordinating physics
  instruction, outreach, and research

abstract:
  This paper describes the development of a new university physics course
designed to integrate physics, education, research, and community partnerships.
The coordinated system of activities links the new course to local community
efforts in pre-college education, university education, university outreach,
and research on teaching and learning. As documented both by gains on
conceptual surveys and by qualitative analyses of field-notes and audiotapes of
class, the course facilitates student learning of physics, as well as student
mastery of theories and practices of teaching and learning physics.
Simultaneously, the course supports university efforts in community outreach
and creates a rich environment for education research. The following narrative
describes the motivation, structure, implementation, effectiveness, and
potential for extending and sustaining this alternative model for university
level science education.


title:
Learning physics in context: a study of student learning about
  electricity and magnetism

abstract:
  This paper re-centres the discussion of student learning in physics to focus
on context. In order to do so, a theoretically-motivated understanding of
context is developed. Given a well-defined notion of context, data from a novel
university class in electricity and magnetism are analyzed to demonstrate the
central and inextricable role of context in student learning. This work sits
within a broader effort to create and analyze environments which support
student learning in the sciences


title:
Solving procedure for a twenty-five diagonal coefficient matrix: direct
  numerical solutions of the three dimensional linear Fokker-Planck equation

abstract:
  We describe an implicit procedure for solving linear equation systems
resulting from the discretization of the three dimensional (seven variables)
linear Fokker-Planck equation. The discretization of the Fokker-Planck equation
is performed using a twenty-five point molecule that leads to a coefficient
matrix with equal number of diagonals. The method is an extension of Stone's
implicit procedure, includes a vast class of collision terms and can be applied
to stationary or non stationary problems with different discretizations in
time. Test calculations and comparisons with other methods are presented in two
stationary examples, including an astrophysical application for the
Miyamoto-Nagai disk potential for a typical galaxy.


title: Lasing from a circular Bragg nanocavity with an ultra-small modal volume

abstract:
  We demonstrate single-mode lasing at telecommunication wavelengths from a
circular nanocavity employing a radial Bragg reflector. Ultra-small modal
volume and Sub milliwatt pump threshold level are observed for lasers with
InGaAsP quantum well active membrane. The electromagnetic field is shown to be
tightly confined within the 300nm central pillar of the cavity. The quality
factors of the resonator modal fields are estimated to be on the order of a few
thousands.


title: Remembering Sergio Fubini

abstract:
  The author recollects Sergio Fubini's impact on field theory (radial
quantization, merons, conformal quantum mechanics) and on MIT.


title: Theory and Experiments on the "Quantum Mind"

abstract:
  This article is a short summary, in Greek, of work presented in English in
the following articles:
  1. Mershin et al. "Towards Experimental Tests of Quantum Effects in
Cytoskeletal Proteins" (physics/0505080)
  2. Mershin et al. "Learning and Memory deficits Upon TAU Accumulation in
Drosophila Mushroom Body Neurons", Learning & Memory 11: 277-287 (2004)


title:
Direct measurement of the radiative lifetime of vibrationally excited OH
  radicals

abstract:
  Neutral molecules, isolated in the gas-phase, can be prepared in a long-lived
excited state and stored in a trap. The long observation time afforded by the
trap can then be exploited to measure the radiative lifetime of this state by
monitoring the temporal decay of the population in the trap. This method is
demonstrated here and used to benchmark the Einstein $A$-coefficients in the
Meinel system of OH. A pulsed beam of vibrationally excited OH radicals is
Stark decelerated and loaded into an electrostatic quadrupole trap. The
radiative lifetime of the upper $\Lambda$-doublet component of the $X
^2\Pi_{3/2}, v=1, J=3/2$ level is determined as $59.0 \pm 2.0$ ms, in good
agreement with the calculated value of $57.7 \pm 1.0$ ms.


title:
Coupling of PbS Quantum Dots to Photonic Crystal Cavities at Room
  Temperature

abstract:
  We demonstrate the coupling of PbS quantum dot emission to photonic crystal
cavities at room temperature. The cavities are defined in 33% Al, AlGaAs
membranes on top of oxidized AlAs. Quantum dots were dissolved in
Poly-methyl-methacrylate (PMMA) and spun on top of the cavities. Quantum dot
emission is shown to map out the structure resonances, and may prove to be
viable sources for room temperature cavity coupled single photon generation for
quantum information processing applications. These results also indicate that
such commercially available quantum dots can be used for passive structure
characterization. The deposition technique is versatile and allows layers with
different dot densities and emission wavelengths to be re-deposited on the same
chip.


title: Instability of human societies as a result of conformity

abstract:
  We introduce a new model that mimics the strong and sudden effects induced by
conformity in tightly interacting human societies. Such effects range from mere
crowd phenomena to dramatic political turmoil. The model is a modified version
of the Ising Hamiltonian. We have studied the properties of this Hamiltonian
using both a Metropolis simulation and analytical derivations. Our study shows
that increasing the value of the conformity parameter, results in a first order
phase transition. As a result a majority of people begin honestly to support
the idea that may contradict the moral principles of a normal human beings
though each individual would support the moral principle without tight
interaction with the society. Thus, above some critical level of conformity our
society occurs to be instable with respect to ideas that might be doubtful. Our
model includes, in a simplified way, human diversity with respect to loyalty to
the moral principles.


title: The Counterintuitive Universe

abstract:
  The major advances in physics have been through counterintuitive
breakthroughs-- ideas that seemed to go against prevailing convictions. In the
twentieth century the Special and General Theory of Relativity and Quantum
Mechanics have provided very good examples of this process. However, twentieth
century physics has led to an impasse, one of the most important unsolved
problems being the unification of gravitation with other interactions. This has
led to another sacred tenet of physics, viz., spacetime as a smooth manifold,
being questioned in latest approaches, be it Quantum Super Strings or other
Quantum Gravity and similar theories. In particular spacetime described by an
underpinning of Planck scale oscillators is investigated.


title:
Two-fluid tokamak equilibria with reversed magnetic shear and sheared
  flow

abstract:
  The aim of the present work is to investigate tokamak equilibria with
reversed magnetic shear and sheared flow, which may play a role in the
formation of internal transport barriers (ITBs), within the framework of
two-fluid model. The study is based on exact self-consistent solutions in
cylindrical geometry by means of which the impact of the magnetic shear, s, and
the "toroidal" (axial) and "poloidal" (azimuthal) ion velocity components on
the radial electric field, its shear and the shear of the ExB velocity is
examined. For a wide parametric regime of experimental concern it turns out
that the contributions of the toroidal and poloidal velocity and pressure
gradient terms to the electric field, its shear and ExB velocity shear are of
the same order of magnitude. The impact of s on ExB velocity shear through the
pressure gradient term is stronger than that through the velocity terms. The
results indicate that, alike MHD, the magnetic shear and the sheared toroidal
and poloidal velocities act synergetically in producing electric fields and
therefore ExB velocity shear profiles compatible with ones observed in
discharges with ITBs; owing to the pressure gadient term, however, the impact
of s on the electic field, its shear and the shear of ExB velocity is stronger
than that in MHD.


title: The Rate of Expansion of Spherical Flames

abstract:
  In this paper we investigate the acceleration of the expansion of premixed
spherical flames and evolution of the cellular patterns on their surfaces. An
asymptotic model is used for the simulations and a spectral numerical algorithm
is employed to study flames over large time intervals. Numerous numerical
experiments indicate that for large enough time intervals the acceleration of
two-dimensional expanding flame ceases and the expansion rate stabilizes to a
value significantly exceeding the burning rate. The importance of the effect of
forcing was also confirmed and the validity of sectorial simulations of closed
flames was studied in order to justify prospective use of the Fourier spectral
model for the three-dimensional spherical flames.


title:
Statistical modelling of tropical cyclone tracks: a comparison of models
  for the variance of trajectories

abstract:
  We describe results from the second stage of a project to build a statistical
model for hurricane tracks. In the first stage we modelled the unconditional
mean track. We now attempt to model the unconditional variance of fluctuations
around the mean. The variance models we describe use a semi-parametric nearest
neighbours approach in which the optimal averaging length-scale is estimated
using a jack-knife out-of-sample fitting procedure. We test three different
models. These models consider the variance structure of the deviations from the
unconditional mean track to be isotropic, anisotropic but uncorrelated, and
anisotropic and correlated, respectively. The results show that, of these
models, the anisotropic correlated model gives the best predictions of the
distribution of future positions of hurricanes.


title:
Optical Levitation of a Droplet under Linear Increase of Gravitational
  Acceleration

abstract:
  Optical levitation of a liquid droplet in gas phase was investigated under
timedependent change of the gravitational acceleration with specific flight
pattern of an airplane. Through multiple trials under linear increase of
effective gravitational acceleration, we performed the experiment of ptical
trapping of a droplet from 0.3g_0 to 0.9g_0, where g_0 = 9.8 m/s^2. During such
change of the effective gravitational acceleration, the trapping position on a
droplet with the radius of 14 μm was found to be lowered by ca. 100
μm. The essential feature of the change of the trapping position is
reproduced by a theoretical calculation under the framework of ray optics. As
far as we know, the present study is the first report on optical levitation
under time-dependent gravitational change.


title:
Effective Dielectric Constants of Photonic Crystal of Aligned
  Anisotropic Cylinders: Application to the Optical Response of Periodic Array
  of Carbon Nanotubes

abstract:
  We calculate the static dielectric tensor of a periodic system of aligned
anisotropic dielectric cylinders. Exact analytical formulas for the effective
dielectric constants for the E- and H- eigenmodes are obtained for arbitrary 2D
Bravais lattice and arbitrary cross-section of anisotropic cylinders. It is
shown that depending on the symmetry of the unit cell photonic crystal of
anisotropic cylinders behaves in the low-frequency limit like uniaxial or
biaxial natural crystal. The developed theory of homogenization of anisotropic
cylinders is applied for calculations of the dielectric properties of photonic
crystals of carbon nanotubes.


title: Purcell factor enhanced scattering efficiency in optical microcavities

abstract:
  Scattering processes in an optical microcavity are investigated for the case
of silicon nanocrystals embedded in an ultra-high Q toroid microcavity. Using a
novel measurement technique based on the observable mode-splitting, we
demonstrate that light scattering is highly preferential: more than 99.8% of
the scattered photon flux is scattered into the original doubly-degenerate
cavity modes. The large capture efficiency is attributed to an increased
scattering rate into the cavity mode, due to the enhancement of the optical
density of states over the free space value and has the same origin as the
Purcell effect in spontaneous emission. The experimentally determined Purcell
factor amounts to 883.


title:
Alice in a micro-factory: modeling materials and mechanisms of natural
  nano-machines

abstract:
  Imagine an under water factory which is about $10 \mu$m long in each
direction. The factory is filled with machines, each typically a few tens of
nanometers long, which perform specfic tasks and operate in a well coordinated
manner. A cell, the structural and functional unit of life, is not very
different from this micro-factory. In this article, I begin with Alice's guided
tour of this micro-factory in her dream during which the guide shows her wide
varieties of the nano-machines in this factory. The style of presentation of
the first half of this article is inspired by Lewis Carrol's {\it Alice in
Wonderland}. In the second half, I introduce the methods of studying the
materials and mechanisms of the molecular machines through dialogues; the three
participants in this discussion are Alice, her elder brother Alex and her
father Albert. The style of presentation of the second half of this article, in
terms of a dialogue, is adapted from Galileo's {\it Dialogue Concerning the Two
Chief World Systems}. Albert, a professor of biophysics, emphasizes the crucial
differences between the mechanisms of the natural nano-machines and those of
their macroscopic counterparts. He also points out some practical applications
of this interdisciplinary research in biomedical science and nano-technology.


title: The Image of a Wormhole

abstract:
  A wormhole is a hypothetical tunnel through space. We employ the techniques
taught in a standard calculus course to generate the images (embedding
diagrams) of the Schwarzschild Wormhole and the Thorne-Morris Wormhole.


title:
Path integral virial estimator based on the scaling of fluctuation
  coordinates: Application to quantum clusters with fourth-order propagators

abstract:
  We first show that a simple scaling of fluctuation coordinates defined in
terms of a given reference point gives the conventional virial estimator in
discretized path integral, where different choices of the reference point lead
to different forms of the estimator (e.g., centroid virial). The merit of this
procedure is that it allows a finite difference evaluation of the virial
estimator with respect to temperature, which totally avoids the need of
higher-order potential derivatives. We apply this procedure to energy and heat
capacity calculation of the (H_2)_22 and Ne_13 clusters at low temperature
using the fourth-order Takahashi-Imada and Suzuki propagators. This type of
calculation requires up to third-order potential derivatives if analytical
virial estimators are used, but in practice only first-order derivatives
suffice by virtue of the finite difference scheme above. From the application
to quantum clusters, we find that the fourth-order propagators do improve upon
the primitive approximation, and that the choice of the reference point plays a
vital role in reducing the variance of the virial estimator.

categories: physics.chem-ph cond-mat.stat-mech physics.atm-clus physics.comp-ph


title:
Performance of a C4F8O Gas Radiator Ring Imaging Cherenkov Detector
  Using Multi-anode Photomultiplier Tubes

abstract:
  We report on test results of a novel ring imaging Cherenkov (RICH) detection
system consisting of a 3 meter long gaseous C4F8O radiator, a focusing mirror,
and a photon detector array based on Hamamatsu multi-anode photomultiplier
tubes. This system was developed to identify charged particles in the momentum
range from 3-70 GeV/c for the BTeV experiment.


title: The radiated fields of the fundamental mode of photonic crystal fibers

abstract:
  The six-fold rotational symmetry of photonic crystal fibers has important
manifestations in the radiated fields in terms of i) a focusing phenomena at a
finite distance from the end-facet and ii) the formation of low-intensity
satellite peaks in the asymptotic far field. For our study, we employ a surface
equivalence principle which allows us to rigorously calculate radiated fields
starting from fully-vectorial simulations of the near field. Our simulations
show that the focusing is maximal at a characteristic distance from the
end-facet. For large-mode area fibers the typical distance is of the order 10
Lambda with Lambda being the pitch of the triangular air-hole lattice of the
photonic crystal fiber.


title: Agents Play Mix-game

abstract:
  In mix-game which is an extension of minority game, there are two groups of
agents; group1 plays the majority game, but the group2 plays the minority game.
This paper studies the change of the average winnings of agents and
volatilities vs. the change of mixture of agents in mix-game model. It finds
that the correlations between the average winnings of agents and the mean of
local volatilities are different with different combinations of agent memory
length when the proportion of agents in group 1 increases. This study result
suggests that memory length of agents in group1 be smaller than that of agent
in group2 when mix-game model is used to simulate the financial markets.


title: Laser Wakefield Acceleration of Particle in a Plasma

abstract:
  A review of the present situation and perspectives, in particular in the
scope of a multi-Tev linear accelerator.


title:
Formation of singularities on the surface of a liquid metal in a strong
  electric field

abstract:
  The nonlinear dynamics of the free surface of an ideal conducting liquid in a
strong external electric field is studied. It is establish that the equations
of motion for such a liquid can be solved in the approximation in which the
surface deviates from a plane by small angles. This makes it possible to show
that on an initially smooth surface for almost any initial conditions points
with an infinite curvature corresponding to branch points of the root type can
form in a finite time.


title: Money Exchange Model and a general Outlook

abstract:
  The Kinetic Gas Theory like two-agent money exchange models, recently
introduced in the Econophysics of Wealth distributions, are revisited. The
emergence of Boltzmann-Gibbs like distribution of individual money to Pareto's
law in the tail of the distribution is examined in terms of 2x2 Transition
matrix with a general and simple oulook. Some additional interesting results
are also reported.


title: Numerical Methods as an Integrated Part of Physics Education

abstract:
  During the last decade we have witnessed an impressive development in
so-called interpreted languages and computational environments such as Maple,
Mathematica, IDL, Matlab etc. Problems which until recently were typically
solved on mainframe machines and written in computing languages such as Fortran
or C/C++, can now easily be solved on standard PCs with the bonus of immediate
visualizations of the results.
  In our undergraduate programs an often posed question is how to incorporate
and exploit efficiently these advances in the standard physics and mathematics
curriculum, without detracting the attention from the classical and basic
theoretical and experimental topics to be covered. Furthermore, if students are
trained to use such tools at early stages in their education, do such tools
really enhance and improve the learning environment? And, perhaps even more
important, does it lead to a better physics understanding?
  Here we present one possible approach, where computational topics are
gradually baked into our undergraduate curriculum in Mathematics and Physics,
Astronomy and Meteorology. We focus on training our students to use general
programming tools in solving physics problems, in addition to the classical
analytic problems. By this approach, the students gain an expertise that they
can build upon in their future studies and careers. We use mainly Java, Matlab
and Maple as computational environments. Our students are now capable of
handling at an early stage in their education more realistic physics problems
than before. We believe firmly that, in addition to educating modern
scientists, this promotes a better physics understanding for a majority of the
students.


title: Multifractal Fingerprints in the Visual Arts

abstract:
  The similarity in fractal dimensions of paint ``blobs'' in samples of
gestural expressionist art implies that these pigment structures are
statistically indistinguishable from one another. This result suggests that
such dimensions cannot be used as a ``fingerprint'' for identifying the work of
a single artist. To overcome this limitation, the multifractal spectrum is
adopted as an alternative tool for artwork analysis. For the pigment blobs, it
is demonstrated that this spectrum can be used to isolate a construction
paradigm or art style. Additionally, the fractal dimensions of edge structures
created by luminance gradients on the canvas are analyzed, yielding a potential
method for visual discrimination of fractally-similar paintings.


title:
The Effects of Temperature, Pressure, and Humidity Variations on 100
  Meter Sprint Performances

abstract:
  It is well known that ``equivalent'' sprint race times run with different
accompanying wind speeds or at different altitudes are anything but equivalent
races. The drag force acting on a sprinter is a function of air density and the
relative wind speed, where the former has traditionally been calculated using
the race venue's elevation above sea level. However, air density variation is
dependent on more than just altitude. This work will quantify how changes in
air temperature, barometric pressure, and humidity levels influence 100 m
sprint performances. When these effects are considered in combination, the
corrections to performances can be very large. The results suggest that a
non-negligible difference in race times can be expected for ``equivalent''
performances run with the same wind speed at the same venue or physical
altitude, but under different atmospheric conditions.


title:
Teaching special relativity at the hundredth anniversary of Einstein's
  "anno mirabilis"

abstract:
  We show that the transformation of relativistic velocities derived without
using the Lorentz-Einstein transformation for the space-time coordinates of the
same event and the fact that we can define the proper value of length, time
interval, mass, electric field intensity enable us to derive transformation
equations for the space-time coordinates of the same event, for mass (energy)
and momentum of the same particle, for the electric field intensity and
magnetic induction generated by the same moving charged particle or
electromagnetic wave and for the frequency and the wave number of the same
electromagnetic wave. The derivations involve a single scenario: a moving
particle that generates events, carries mass (energy) and momentum, electric
charge creating electric and magnetic fields. A plane electromagnetic wave is
also involved.


title:
A Simple Hypothesis on the Origin and Physical Nature of Quantum
  Superposition of States

abstract:
  We suugest a simple hypothesis on physical origin of quantum superposition,
which is a generalization of our "hidden time" hypothesis, suggested before.


title:
Numerical Solutions of 2-D Steady Incompressible Flow in a Driven Skewed
  Cavity

abstract:
  The benchmark test case for non-orthogonal grid mesh, the "driven skewed
cavity flow", first introduced by Demirdzic et al. (1992, IJNMF, 15, 329) for
skew angles of alpha=30 and alpha=45, is reintroduced with a more variety of
skew angles. The benchmark problem has non-orthogonal, skewed grid mesh with
skew angle (alpha). The governing 2-D steady incompressible Navier-Stokes
equations in general curvilinear coordinates are solved for the solution of
driven skewed cavity flow with non-orthogonal grid mesh using a numerical
method which is efficient and stable even at extreme skew angles. Highly
accurate numerical solutions of the driven skewed cavity flow, solved using a
fine grid (512x512) mesh, are presented for Reynolds number of 100 and 1000 for
skew angles ranging between 15<alpha<165.

categories: physics.flu-dyn cs.NA math.NA physics.comp-ph


title:
Light propagation in a horizontally homogeneous Lambertian foliage:
  Analytically solvable models

abstract:
  Various numerical methods exist for obtaining the radiances inside a canopy
of leaves above a partly reflecting ground. In view of testing the accuracy of
these diverse methods, it is desirable to have at one's disposal non-trivial
models possessing analytical solutions, against which to compare numerical
reuslts. Such models are obtained in the present paper, for the case of a
horizontally homogeneous foliage of Lambertian leaves, modeled as a turbid
medium. Our treatment is more general than usual in that we allow the top and
under sides of leaves to have different optical coefficients. Besides being
more realistic, this enables artificial situations, such as extreme light
trapping, testing the limits of various numerical methods.


title: Atmospheric electrification in the Solar System

abstract:
  Atmospheric electrification is not a purely terrestrial phenomenon: all Solar
System planetary atmospheres become slightly electrified by cosmic ray
ionisation. There is evidence for lightning on Jupiter, Saturn, Uranus and
Neptune, and it appears likely to exist on Mars, Venus and Titan. Atmospheric
electricity has controversially been implicated in climate on Earth; here, a
comparative approach is employed to review the role of electrification in the
atmospheres of other planets and their moons. This paper reviews planetary
atmospheric electricity including ionisation and ion-aerosol interactions. The
conditions necessary for a global electric circuit, and the likelihood of
meeting these conditions in other planetary atmospheres are briefly discussed.
Atmospheric electrification could be important throughout the Solar System,
particularly at the outer planets which receive little solar radiation,
increasing the significance of electrical forces. Nucleation onto atmospheric
ions has been predicted to affect the evolution and lifetime of haze layers on
Titan, Neptune, and Triton. Atmospheric electrical processes on Titan,
pre-Huygens, are summarised. Closer to Earth, heating from solar radiation
dominates planetary meteorology; however Mars may have a global circuit based
on electrical discharges from dust storms. There is a need for direct
measurements of planetary atmospheric electrification, in particular on Mars,
to assess the risk for future missions. Theoretical understanding could be
increased by cross-disciplinary work to modify and update models and
parameterisations initially developed for specific planetary atmospheres to
make them more broadly applicable.


title: Weak antilocalization of ultrarelativistic fermions

abstract:
  The paper discusses the Berry phase influence on the weak localization
phenomenon at the adiabatic backscattering of ultrarelativistic particles in a
random medium. We demonstrate that bosons that pass along a certain closed path
in opposite directions come back always in phase (an example: the
backscattering enhancement of electromagnetic waves), whereas fermions come
exactly in antiphase. This produces a "complete weak antilocalization" of
ultrarelativistic fermions: the backscattering field intensity vanishes.


title: The return branch of viscous fingers

abstract:
  We report a simple experiment of two-dimensional pattern formation in a
circular Hele-Shaw cell, showing the appearance of a return branch that is
equivalent to the upward-connecting leader of lightning. Injecting water from
the center into a foam filled cell, we obtained patterns similar to dendrites
of two-dimensional dielectric breakdown experiments. When we repeat this
experiment allowing the presence of water in the outer (low pressure) region,
dendrites grow initially as in a normal experiment, but when a branch is near
the outer boundary, the low pressure water begins to penetrate the foam against
the pressure field, forming several return branches.


title:
Particle motion in microfluidics simulated using a Femlab implementation
  of the level set method

abstract:
  We implement the level set method for numerical simulation of the motion of a
suspended particle convected by the fluid flow in a microchannel. The method
automatically cope with the interactions between the particle and the channel
walls. We apply the method in a study of particles moving in a channel with
obstacles of different shapes. The generality of the method also makes it
applicable for simulations of motion of particles under influence of external
forces.


title:
Position resolution and particle identification with the ATLAS EM
  calorimeter

abstract:
  In the years between 2000 and 2002 several pre-series and series modules of
the ATLAS EM barrel and end-cap calorimeter were exposed to electron, photon
and pion beams. The performance of the calorimeter with respect to its finely
segmented first sampling has been studied. The polar angle resolution has been
found to be in the range 50-60 mrad/sqrt(E (GeV)). The neutral pion rejection
has been measured to be about 3.5 for 90% photon selection efficiency at pT=50
GeV/c. Electron-pion separation studies have indicated that a pion fake rate of
(0.07-0.5)% can be achieved while maintaining 90% electron identification
efficiency for energies up to 40 GeV.


title: A spatial model for social networks

abstract:
  We study spatial embeddings of random graphs in which nodes are randomly
distributed in geographical space. We let the edge probability between any two
nodes to be dependent on the spatial distance between them and demonstrate that
this model captures many generic properties of social networks, including the
``small-world'' properties, skewed degree distribution, and most distinctively
the existence of community structures.


title: On the mechanism of branching in negative ionization fronts

abstract:
  We explain a mechanism for branching of a planar negative front. Branching
occurs as the result of a balance between the destabilizing effect of impact
ionization and the stabilizing effect of electron diffusion on ionization
fronts. The dispersion relation for transversal perturbation is obtained
analytically and reads: $s = |k|/[2 (1 + |k|)] - D |k|^2$, where $D$, which is
assumed to be small, is the ratio between the electron diffusion coefficient
and the intensity of the externally imposed electric field. We estimate the
spacing $\lambda$ between streamers in a planar discharge and deduce a scaling
law $\lambda \sim D^{1/3}$.


title:
Relativistic velocity transformation as a genitor of transformation
  equations (electrodynamics)

abstract:
  We show that invariance of the electric charge and relativistic kinematics
lead to the transformation equations for electric field intensity and the
magnetic induction.


title:
Long range intermolecular forces in triatomic systems: connecting the
  atom-diatom and atom-atom-atom representations

abstract:
  The long-range forces that act between three atoms are analysed in both
atom-diatom and atom-atom-atom representations. Expressions for atom-diatom
dispersion coefficients are obtained in terms of 3-body nonadditive
coefficients. The anisotropy of atom-diatom C_6 dispersion coefficients arises
primarily from nonadditive triple-dipole and quadruple-dipole forces, while
pairwise-additive forces and nonadditive triple-dipole and
dipole-dipole-quadrupole forces contribute significantly to atom-diatom C_8
coefficients. The resulting expressions are applied to dispersion coefficients
for Li + Li_2 (triplet) and recommendations are made for the best way to obtain
global triatomic potentials that dissociate correctly both to three separated
atoms and to an atom and a diatomic molecule.


title: Quasiresonance

abstract:
  The concept of quasiresonance was introduced in connection with inelastic
collisions between one atom and a vibro-rotationally excited diatomic molecule.
In its original form, the collisions induce {\sl quasiresonant} transfer of
energy between the internal degrees of freedom of the diatom: there is a
surprisingly accurate low order rational value for the ratio of the changes in
the vibrational and rotational classical actions, provided the vibrational and
rotational frequencies of the diatom are approximately related by low order
rational values, and the collision was longer that the rotational period of the
molecule. In this paper we show that quasiresonance can be extended to many
other processes and systems, and that it may be understood in terms of the
adiabatic invariance theory and the method of averaging.


title:
Effects of the baroclinic adjustment on the tropopause in the NCEP-NCAR
  reanalysis

abstract:
  In this work, we study the mean tropopause structure from the NCEP-NCAR
reanalysis in the framework of a theory of baroclinic adjustment, focusing on
the impact of baroclinic eddies on the mean tropopause height. In order to
measure the effects of such perturbations, we introduce an appropriate global
index that selects events of high baroclinic activity and allows us to
individuate the phases of growth and decay of baroclinic waves. We then
composite the tropopause mean structure before and after a baroclinic event,
finding that baroclinic disturbances cause the zonally averaged midlatitude
winter tropopause height to rise. Our results suggest that the baroclinic
adjustment processes should be taken into account to explain the nature of the
midlatitude tropopause.


title: Visualizing proper-time in Special Relativity

abstract:
  We present a new visualization of the proper-time elapsed along an observer's
worldline. By supplementing worldlines with light clocks, the measurement of
space-time intervals is reduced to the "counting of ticks." The resulting
space-time diagrams are pedagogically attractive because they emphasize the
relativistic view that "time is what is measured by an observer's clock."


title: Thermodynamic theory of kinetic overshoots

abstract:
  Everything that is not prohibited is permissible. So, what is prohibited in
the course of chemical reactions, heat transfer and other dissipative
processes? Is it possible to "overshoot" the equilibrium, and if yes, then how
far? Thermodynamically allowed and prohibited trajectories of processes are
discussed by the example of effects of equilibrium encircling. The complete
theory of thermodynamically accessible states is presented. The space of all
thermodynamically admissible paths is presented by projection on the
"thermodynamic tree", that is the tree of the related thermodynamic potential
(entropy, free energy, free enthalpy) in the balance polyhedron. The stationary
states and limit points for open systems are localized too.


title:
Correlations between the most developed (G7) countries. A moving average
  window size optimisation

abstract:
  Different distance matrices are defined and applied to look for correlations
between the gross domestic product of G7 countries. Results are illustrated
through displays obtained from various graph methods. Significant similarities
between results are obtained. A procedure for choosing the best distance
function is proposed taking into account the size of the window in which
correlation are averaged.


title: Complex Networks as Hypergraphs

abstract:
  The representation of complex systems as networks is inappropriate for the
study of certain problems. We show several examples of social, biological,
ecological and technological systems where the use of complex networks gives
very limited information about the structure of the system. We propose to use
hypergraphs to represent these systems by introducing the concept of the
complex hyper-network. We define several structural measures for complex
hyper-networks. These measures characterize hyper-network structures on the
basis of node participation in different hyper-edges (groups) and
sub-hypergraphs. We also define two clustering coefficients, one characterizing
the transitivity in the hyper-network through the proportion of hyper-triangles
to paths of length two and the other characterizing the formation of triples of
mutually adjacent groups in the hyper-network. All of these characteristics are
studied in two different hyper-networks; a scientific collaboration
hyper-network and an ecological competence hyper-network.


title:
Double-component convection due to different boundary conditions in an
  infinite slot diversely oriented to the gravity

abstract:
  Onset of small-amplitude oscillatory and both small- and finite-amplitude
steady double-component convection arising due to component different boundary
conditions in an infinite slot is studied for various slot orientations to the
gravity. The main focus is on two compensating background gradients of the
components. The physical mechanisms underlying steady and oscillatory
convection are analyzed from the perspective of a universally consistent
understanding of the effects of different boundary conditions.


title: Quantum effects from a purely geometrical relativity theory

abstract:
  A purely geometrical relativity theory results from a construction that
produces from three-dimensional space a happy unification of Kaluza's
five-dimensional theory and Weyl's conformal theory. The theory can provide
geometrical explanations for the following observed phenomena, among others:
(a) lifetimes of elementary particles of lengths inversely proportional to
their rest masses; (b) the equality of charge magnitude among all charged
particles interacting at an event; (c) the propensity of electrons in atoms to
be seen in discretely spaced orbits; and (d) `quantum jumps' between those
orbits. This suggests the possibility that the theory can provide a
deterministic underpinning of quantum mechanics like that provided to
thermodynamics by the molecular theory of gases.


title: A Femtosecond Neutron Source

abstract:
  The possibility to use the ultrashort ion bunches produced by circularly
polarized laser pulses to drive a source of fusion neutrons with sub-optical
cycle duration is discussed. A two-side irradiation of a thin foil deuterated
target produces two countermoving ion bunches, whose collision leads to an
ultrashort neutron burst. Using particle-in-cell simulations and analytical
modeling, it is evaluated that, for intensities of a few $10^{19} W cm^{-2}$,
more than $10^3$ neutrons per Joule may be produced within a time shorter than
one femtosecond. Another scheme based on a layered deuterium-tritium target is
outlined.


title:
Spiral vortices traveling between two rotating defects in the
  Taylor-Couette system

abstract:
  Numerical calculations of vortex flows in Taylor-Couette systems with counter
rotating cylinders are presented. The full, time dependent Navier-Stokes
equations are solved with a combination of a finite difference and a Galerkin
method. Annular gaps of radius ratio $\eta=0.5$ and of several heights are
simulated. They are closed by nonrotating lids that produce localized Ekman
vortices in their vicinity and that prevent axial phase propagation of spiral
vortices. Existence and spatio temporal properties of rotating defects, of
modulated Ekman vortices, and of the spiral vortex structures in the bulk are
elucidated in quantitative detail.


title:
Measuring sectoral diversification in an asymptotic multi-factor
  framework

abstract:
  We investigate a multi-factor extension of the asymptotic single risk factor
(ASRF) model that underlies the capital charges of the "Basel II Accord". In
this extended model, it is still possible to derive closed-form solutions for
the risk contributions to Value-at-Risk and Expected Shortfall. As an
application of the risk contribution formulae we introduce a new concept for a
diversification measure. The use of this new measure is illustrated by an
example calculated with a two-factor model. The results with this model
indicate that, thanks to dependence on not fully correlated systematic sectors,
there can be a substantial reduction of risk contributions by sectoral
diversification effects.


title:
The role of quasi-momentum in the resonant dynamics of the atom-optics
  kicked rotor

abstract:
  We examine the effect of the initial atomic momentum distribution on the
dynamics of the atom-optical realisation of the quantum kicked rotor. The atoms
are kicked by a pulsed optical lattice, the periodicity of which implies that
quasi-momentum is conserved in the transport problem. We study and compare
experimentally and theoretically two resonant limits of the kicked rotor: in
the vicinity of the quantum resonances and in the semiclassical limit of
vanishing kicking period. It is found that for the same experimental
distribution of quasi-momenta, significant deviations from the kicked rotor
model are induced close to quantum resonance, while close to the classical
resonance (i.e. for small kicking period) the effect of the quasi-momentum
vanishes.


title:
Evidences of a threshold system as the source for magnetic storms
  detected on Earth s surface

abstract:
  Threshold systems appear to underlie the global behaviour of physical
phenomena very unlike at a first look. The usual experimental fingerprint of
threshold system grounded phenomena is the presence of power laws. Experimental
evidence has been found, for example, in superconductor vortex avalanches, sand
piles, the brain, 4He superfluidity and earthquakes. Double power-laws have
been found in social networks, in the luminosity of some galactic nuclei and,
very recently, in solar flares, among others. Here we show evidences that point
to a threshold system as the source for magnetic storms detected on the Earth.
We based our analysis on series of data acquired during many years in the
network of magnetic observatories of the National Observatory (Brazil). In
particular we focused our attention on October 2000 month of the Vassouras
Observatory (RJ, Brazil), which have been active since 1915. We have found both
power laws and double power laws for some relevant distributions.