title: A minimum principle in mRNA editing ?

abstract:
  mRNA editing of sequences of many species is analyzed. The nature of the
inserted nucleotides and the position of the insertion sites, once fixed the
edited peptide chain, are explained by introducing a minimum principle in the
framework of the crystal basis model of the genetic code introduced by the
authors.


title:
Confidence intervals for the parameter of Poisson distribution in
  presence of background

abstract:
  A results of numerical procedure for construction of confidence intervals for
parameter of Poisson distribution for signal in the presence of background
which has Poisson distribution with known value of parameter are presented. It
is shown that the described procedure has both Bayesian and frequentist
interpretations.


title:
Investigation of the Kerr-lens Mode Locking Ability of Cr:ZnSe
  Solid-State Laser

abstract:
  The theoretical calculation for nonlinear refractive index in Cr: ZnSe -
active medium predicts the strong defocusing cascaded second-order nonlinearity
within 2000 - 3000 nm spectral range. On the basis of this result the optimal
cavity configuration for Kerr-lens mode locking is proposed that allows to
achieve a sub-100 fs pulse duration. The numerical simulations testify about
strong destabilizing processes in the laser resulting from a strong self-phase
modulation. The stabilization of the ultrashort pulse generation is possible
due to spectral filtering that increases the pulse duration up to 300 fs.


title: p/e Geometric Mass Ratio

abstract:
  A previously proposed geometric definition of mass in terms of energy, in a
geometrical unified theory, is used to obtain a numerical expression for a
ratio of masses of geometrical excitations. The resultant geometric ratio is
approximately equal the ratio of the proton to electron physical masses.


title:
Nonlinear Effects in CW Mode-Locked Solid-State Lasers with
  Semiconductor Saturable Absorbers

abstract:
  The influence of nonlinear properties of semiconductor saturable absorbers on
ultrashort pulse generation was investigated. It was shown, that linewidth
enhancement, quadratic and linear ac Stark effect contribute essentially to the
mode locking in cw solid-state lasers, that can increase the pulse stability,
decrease pulse duration and reduce the mode locking threshold


title:
Study Notes on Numerical Solutions of the Wave Equation with the Finite
  Difference Method

abstract:
  In this introductory work I will present the Finite Difference method for
hyperbolic equations, focusing on a method which has second order precision
both in time and space (the so-called staggered leapfrog method) and applying
it to the case of the 1d and 2d wave equation. A brief derivation of the energy
and equation of motion of a wave is done before the numerical part in order to
make the transition from the continuum to the lattice clearer. To illustrate
the extension of the method to more complex equations, I also add dissipative
terms of the kind $-\eta \dot{u}$ into the equations. The von Neumann numerical
stability analysis and the Courant criterion, two of the most popular in the
literature, are briefly discussed. In the end I present some numerical results
obtained with the leapfrog algorithm, illustrating the importance of the
lattice resolution through energy plots.


title: Lamb Shift in Light Hydrogen-Like Atoms

abstract:
  Calculation of higher-order two-loop corrections is now a limiting factor in
development of the bound state QED theory of the Lamb shift in the hydrogen
atom and in precision determination of the Rydberg constant. Progress in the
study of light hydrogen-like ions of helium and nitrogen can be helpful to
investigate these uncalculated terms experimentally. To do that it is necessary
to develop a theory of such ions. We present here a theoretical calculation for
low energy levels of helium and nitrogen ions.


title: Nuclear spin conversion in formaldehyde

abstract:
  Theoretical model of the nuclear spin conversion in formaldehyde (H2CO) has
been developed. The conversion is governed by the intramolecular spin-rotation
mixing of molecular ortho and para states. The rate of conversion has been
found equal 1.4*10^{-4}~1/s*Torr. Temperature dependence of the spin conversion
has been predicted to be weak in the wide temperature range T=200-900 K.


title:
Relativistic corrections to the dipole polarizability of the ground
  state of the molecular ion H_2^+

abstract:
  The recently reported precise experimental determination of the dipole
polarizability of the H_2^+ molecular ion ground state [P.L. Jacobson, R.A.
Komara, W.G. Sturrus, and S.R. Lundeen, Phys. Rev. A 62, 012509 (2000)] reveals
a discrepancy between theory and experiment of about 0.0007a_0^3, which has
been attributed to relativistic and QED effects. In present work we analyze an
influence of the relativistic effects on the scalar dipole polarizability of an
isolated H_2^+ molecular ion. Our conclusion is that it accounts for only 1/5
of the measured discrepancy.


title:
Spin Relaxation Resonances Due to the Spin-Axis Interaction in Dense
  Rubidium and Cesium Vapor

abstract:
  Resonances in the magnetic decoupling curves for the spin relaxation of dense
alkali-metal vapors prove that much of the relaxation is due to the spin-axis
interaction in triplet dimers. Initial estimates of the spin-axis coupling
coefficients for the dimers are 290 MHz for Rb; 2500 MHz for Cs.


title: Non-destructive spatial heterodyne imaging of cold atoms

abstract:
  We demonstrate a new method for non-destructive imaging of laser-cooled
atoms. This spatial heterodyne technique forms a phase image by interfering a
strong carrier laser beam with a weak probe beam that passes through the cold
atom cloud. The figure of merit equals or exceeds that of phase-contrast
imaging, and the technique can be used over a wider range of spatial scales. We
show images of a dark spot MOT taken with imaging fluences as low as 61 pJ/cm^2
at a detuning of 11 linewidths, resulting in 0.0004 photons scattered per atom.


title: Definition of the elements of length and time by means of photon

abstract:
  This paper has been withdrawn by the author due to the presented idea is
wrong.


title:
Numerical Calculation of Coherent Synchrotron Radiation Effects Using
  TraFiC4

abstract:
  Coherent synchrotron radiation (CSR) occurs when short bunches travel on
strongly bent trajectories. Its effects on high-quality beams can be severe and
are well understood qualitatively. For quantitative results, however, one has
to rely on numerical methods. There exist several simulation codes utilizing
different approaches. We describe in some detail the code TraFiC4 developed at
DESY for design and analysis purposes, which approaches the problem from first
principles and solves the equations of motion either perturbatively or
self-consistently. We present some calculational results and comparison with
experimental data. Also, we give examples of how the code can be used to design
beamlines with minimal emittance growth due to CSR.


title:
Analysis of Causality Issue in Near-field Superluminally Propagating
  Electromagnetic and Gravitational Fields

abstract:
  A simple relativistic analysis is presented which shows that near-field
superluminal longitudinal electric signals generated by an electric dipole
cannot be used to violate Einstein causality by using the relativistic "sync
shift" effect. The analysis shows that because a signal has some time extent
(i.e. after a signal is initiated one must waitat least one period for the
frequency and amplitude information to be determined), an electric dipole can
be used to transmit a signal backward in time, but not before the same signal
was initiated, thereby prohibiting a user from changing the signal that was
transmitted. The result is also shown to apply to the superluminal near-field
gravitational fields generated by an oscillating mass.


title:
New Particle and Energy "Timeless Particle" and "Timeless Energy" that
  Existed Before the Beginning of Time

abstract:
  This paper gives preliminary information regarding the new particles and
energies titled "Timeless Particle" and "Timeless Energy" that existed before
the beginning of time.


title: Spin-axis relaxation in spin-exchange collisions of alkali atoms

abstract:
  We present calculations of spin-relaxation rates of alkali-metal atoms due to
the spin-axis interaction acting in binary collisions between the atoms. We
show that for the high-temperature conditions of interest here, the spin
relaxation rates calculated with classical-path trajectories are nearly the
same as those calculated with the distorted-wave Born approximation. We compare
these calculations to recent experiments that used magnetic decoupling to
isolate spin relaxation due to binary collisions from that due to the formation
of triplet van-der-Waals molecules. The values of the spin-axis coupling
coefficients deduced from measurements of binary collision rates are consistent
with those deduced from molecular decoupling experiments. All the experimental
data is consistent with a simple and physically plausible scaling law for the
spin-axis coupling coefficients.


title: Relativistic quantum physics with hyperbolic numbers

abstract:
  A representation of the quadratic Dirac equation and the Maxwell equations in
terms of the three-dimensional universal complex Clifford algebra is given. The
investigation considers a subset of the full algebra, which is isomorphic to
the Baylis algebra. The approach is based on the two Casimir operators of the
Poincare group, the mass operator and the spin operator, which is related to
the Pauli-Lubanski vector. The extension to spherical symmetries is discussed
briefly. The structural difference to the Baylis algebra appears in the shape
of the hyperbolic unit, which plays an integral part in this formalism.


title:
The Energy of the Universe, the Scaling-Dependent Coupling Constant
  $\beta$ and the Pion Mass

abstract:
  From the hypothesis of a quadratic dependence of the binding energy of the
quarks on the length scale and from the idea of a universal running coupling
constant, we get the closure mass of the Universe and the pion mass. Besides
this, we propose a free energy for the pions which stationarity condition leads
to a closed form for the pion mass as a function of the Planck mass and of the
Hubble constant.


title:
On resistive magnetohydrodynamic equilibria of an axisymmetric toroidal
  plasma with flow

abstract:
  It is shown that the magnetohydrodynamic equilibrium states of an
axisymmetric toroidal plasma with finite resistivity and flows parallel to the
magnetic field are governed by a second-order partial differential equation for
the poloidal magnetic flux function $\psi$ coupled with a Bernoulli type
equation for the plasma density (which are identical in form to the
corresponding ideal MHD equilibrium equations) along with the relation
$\Delta^\star \psi=V_c \sigma$. (Here, $\Delta^\star$ is the
Grad-Schl\"{u}ter-Shafranov operator, $\sigma$ is the conductivity and $V_c$ is
the constant toroidal-loop voltage divided by $2 \pi $). In particular, for
incompressible flows the above mentioned partial differential equation becomes
elliptic and decouples from the Bernoulli equation [H. Tasso and G. N.
Throumoulopoulos, Phys. Plasmas {\bf 5}, 2378 (1998)]. For a conductivity of
the form $\sigma=\sigma(R, \psi)$ ($R$ is the distance from the axis of
symmetry) several classes of analytic equilibria with incompressible flows can
be constructed having qualitatively plausible $\sigma$ profiles, i.e. profiles
with $\sigma$ taking a maximum value close to the magnetic axis and a minimum
value on the plasma surface. For $\sigma=\sigma(\psi)$ consideration of the
relation $\Delta^\star\psi = V_c \sigma(\psi)$ in the vicinity of the magnetic
axis leads therein to a proof of the non-existence of either compressible or
incompressible equilibria. This result can be extended to the more general case
of non-parallel flows lying within the magnetic surfaces.


title:
Approximation properties of basis functions in variational three-body
  problem

abstract:
  A new variational basis with well-behaved local approximation properties and
multiple output is proposed for Coulomb systems. The trial function has proper
behaviour at all Coulomb centres. Nonlinear asymptotic parameters are
introduced softly: they do not destroy the self-optimized local behaviour of
the wave function at vanishing interparticle distances. The diagonalization of
the Hamiltonian on a finite Hilbert subspace gives a number of meaningful
eigenvalues. Thus together with the ground state some excited states are also
reliably approximated. For three-body systems all matrix elements are
analytically obtainable up to rational functions of asymptotic parameters. The
feasibility of the new basis usage has been proved by a pilot computer algebra
calculation. The negative sign of an electron pair local energy at their
Coulomb centre has been revealed.
  PACS number: 31.15.Pf


title: Quantized Fractal Space Time and Stochastic Holism

abstract:
  The space time that is used in relativistic Quantum Mechanics and Quantum
Field Theory is the Minkowski space time. Yet, as pointed out by several
scholars this classical space time is incompatible with the Heisenberg
Uncertainity Principle: We cannot go down to arbitrarily small space time
intervals, let alone space time points. Infact this classical space time is at
best an approximation, and this has been criticised by several scholars. We
investigate, what exactly this approximation entails.


title:
Issues and Ramifications in Quantized Fractal Space Time: An Interface
  with Quantum Superstrings

abstract:
  Recently a stochastic underpinning for space time has been considered, what
may be called Quantized Fractal Space Time. This leads us to a number of very
interesting consequences which are testable, and also provides a rationale for
several otherwise inexplicable features in Particle Physics and Cosmology.
These matters are investigated in the present paper.


title: Characterization of Fundamental Particles

abstract:
  This report provides an alternative to the Standard Model of particle
physics. The model described here is based on results from Quantum Field
Mechanics, according to which all fundamental particles and interactions
originate from the interaction of two pre-space/pre-time protofields. In
contrast with the Standard Model, (virtual) interaction-particles are absent in
the description of any of the four fundamental interactions. Electrons perform
a single quantum beat process while mesons and baryons have, respectively, two
and three bound quantum beat processes. Quantum Field Mechanics suggests that
the charge of an electron and positron can be identified with the two possible
phases of a quantum beat process as observed in the electromagnetic protofield.
This report assumes that short-range binding interaction between quantum beat
processes has a masking effect on the externally observable charge of hadrons.
Using this assumption, the internal structure of particles is derived from
their known particle charges and relative masses. The particle structures are
used to obtain the so-called charge-quantum phase law. The fractional charge of
quantum beat processes inside a particle is deduced by rewriting the
charge-quantum phase law in terms of a linear combination of charge
contributions of individual constituent quantum beat processes. Strangeness and
isospin are mathematically defined in terms of the quantum beat phases of sets
of particles of the same type. Application of conservation laws to particle
processes leads to relations between quantum phase, strangeness and isospin.


title:
Formation and Primary Heating of The Solar Corona - Theory and
  Simulation

abstract:
  An integrated Magneto-Fluid model, that accords full treatment to the
Velocity fields associated with the directed plasma motion, is developed to
investigate the dynamics of coronal structures. It is suggested that the
interaction of the fluid and the magnetic aspects of plasma may be a crucial
element in creating so much diversity in the solar atmosphere. It is shown that
the structures which comprise the solar corona can be created by particle
(plasma) flows observed near the Sun's surface - the primary heating of these
structures is caused by the viscous dissipation of the flow kinetic energy.


title: Measuring and Controlling the Energy Spread in CEBAF

abstract:
  As compared to electron storage rings, one advantage of recirculating linear
accelerators is that the beam properties at target are no longer dominated by
the equilibrium between quantum radiative diffusion and radiation damping
because new beam is continually injected into the accelerator. This allows the
energy spread from a CEBAF-type machine to be relatively small; the measured
energy spread from CEBAF at 4 GeV is less than 100 parts per million
accumulated over times of order several days. In this paper, the various
subsystems contributing to the energy spread of a CEBAF-type accelerator are
reviewed, as well as the machine diagnostics and controls that are used in
CEBAF to ensure that a small energy spread is provided during routine running.
Examples of relevant developments are (1) stable short bunches emerging from
the injector, (2) precision timing and phasing of the linacs with respect to
the centroid of the beam bunches on all passes, (3) implementing 2 kHz sampling
rate feedback systems for final energy stabilization, and (4) continuous beam
energy spread monitoring with optical transition radiation devices. We present
measurement results showing that small energy spreads are achieved over
extended periods.


title:
On the quantum aspects of the logarithmic corrections to the black hole
  entropy

abstract:
  A new relativity theory, or more concretely an extended relativity theory,
actively developed by one of the authors incorporates 3 basic concepts. They
are the old idea of Chew about bootstrapping, Nottale's scale relativity, and
enlargement of the conventional time-space by inclusion of noncommutative
Clifford manifolds where all p-branes are treated on equal footing. The latter
allows one to write a master action functional. The resulting functional
equation is simplified and applied to the p-loop oscillator. Its solution
represents a generalization of the conventional quantum point oscillator. In
addition, it exhibits some novel features: an emergence of two explicit scales
delineating the asymptotic regimes (Planck scale region and a smooth region of
a quantum point oscillator). In the most interesting Planck scale regime, the
solution recovers in an elementary fashion some basic relations of string
theory (including string tension quantization and string uncertainty relation).
It is shown that the degeneracy of the $first$ collective excited state of the
p-loop oscillator yields not only the well-known Bekenstein-Hawking
area-entropy linear relation but also the logarithmic corrections therein. In
addition we obtain for any number of dimensions the Hawking temperature, the
Schwarschild radius, and the inequalities governing the area of a black hole
formed in a fusion of two black holes. One of the interesting results is a
demonstration that the evaporation of a black hole is limited by the upper
bound on its temperature, the Planck temperature.


title:
Extracting molecular Hamiltonian structure from time-dependent
  fluorescence intensity data

abstract:
  We propose a formalism for extracting molecular Hamiltonian structure from
inversion of time-dependent fluorescence intensity data. The proposed method
requires a minimum of \emph{a priori} knowledge about the system and allows for
extracting a complete set of information about the Hamiltonian for a pair of
molecular electronic surfaces.


title: Electron Self Energy for the K and L Shell at Low Nuclear Charge

abstract:
  A nonperturbative numerical evaluation of the one-photon electron self energy
for the K- and L-shell states of hydrogenlike ions with nuclear charge numbers
Z=1 to 5 is described. Our calculation for the 1S state has a numerical
uncertainty of 0.8 Hz in atomic hydrogen, and for the L-shell states (2S and
2P) the numerical uncertainty is 1.0 Hz. The method of evaluation for the
ground state and for the excited states is described in detail. The numerical
results are compared to results based on known terms in the expansion of the
self energy in powers of (Z alpha).


title:
Electromagnetically induced absorption in magneto-optically trapped
  atoms

abstract:
  Electromagnetically induced absorption (EIA) was observed on a sample of $%
^{85}Rb$ in a magneto-optical trap using low intensity cw copropagating pump
and probe optical fields. At moderate trapping field intensity, the EIA
spectrum is determined by the Zeeman effect produced on the atomic ground-state
by the trapping quadrupolar magnetic field. The use of EIA spectroscopy for the
magnetic field mapping of cold atomic samples is illustrated.


title: Microtorus: a High Finesse Microcavity with Whispering-Gallery Modes

abstract:
  We have demonstrated a 165 micron oblate spheroidal microcavity with free
spectral range 383.7 GHz (3.06nm), resonance bandwidth 25 MHz (Q ~ 10^7) at
1550nm, and finesse F > 10^4. The highly oblate spheroidal dielectric
microcavity combines very high Q-factor, typical of microspheres, with vastly
reduced number of excited whispering-gallery (WG) modes (by two orders of
magnitude). The very large free spectral range in the novel microcavity - few
hundred instead of few GigaHertz in typical microspheres - is desirable for
applications in spectral analysis, narrow-linewidth optical and RF oscillators,
and cavity QED.

categories: physics.optics physics.chem-ph physics.ins-det quant-ph


title: Slow light in moving media

abstract:
  We review the theory of light propagation in moving media with extremely low
group velocity. We intend to clarify the most elementary features of
monochromatic slow light in a moving medium and, whenever possible, to give an
instructive simplified picture.


title:
Comment on Mie Scattering from a Sonoluminescing Bubble with High
  Spatial and Temporal Resolution [Physical Review E 61, 5253 (2000)]

abstract:
  A key parameter underlying the existence of sonoluminescence (SL)is the time
relative to SL at which acoustic energy is radiated from the collapsed bubble.
Light scattering is one route to this quantity. We disagree with the statement
of Gompf and Pecha that -highly compressed water causes the minimum in
scattered light to occur 700ps before SL- and that this effect leads to an
overestimate of the bubble wall velocity. We discuss potential artifacts in
their experimental arrangement and correct their description of previous
experiments on Mie scattering.


title:
MOE11 Emittance Growth from the Thermalization of Space-Charge
  Nonuniformities

abstract:
  Beams injected into a linear focusing channel typically have some degree of
space-charge nonuniformity. In general, injected particle distributions with
systematic charge nonuniformities are not equilibria of the focusing channel
and launch a broad spectrum of collective modes. These modes can phase-mix and
have nonlinear wave-wave interactions which, at high space-charge intensities,
results in a relaxation to a more thermal-like distribution characterized by a
uniform density profile. This thermalization can transfer self-field energy
from the initial space-charge nonuniformity to the local particle temperature,
thereby increasing beam phase space area (emittance growth). In this paper, we
employ a simple kinetic model of a continuous focusing channel and build on
previous work that applied system energy and charge conservation quantify
emittance growth associated with the collective thermalization of an initial
azimuthally symmetric, rms matched beam with a radial density profile that is
hollowed or peaked. This emittance growth is shown to be surprisingly modest
even for high beam intensities with significant radial structure in the initial
density profile.


title: A two wire waveguide and interferometer for cold atoms

abstract:
  A versatile miniature de Broglie waveguide is formed by two parallel
current-carrying wires in the presence of a uniform bias field. We derive a
variety of analytical expressions to describe the guide and present a quantum
theory to show that it offers a remarkable range of possibilities for atom
manipulation on the sub-micron scale. These include controlled and coherent
splitting of the wavefunction as well as cooling, trapping and guiding. In
particular we discuss a novel microscopic atom interferometer with the
potential to be exceedingly sensitive.


title: Passive Tracer Dynamics in 4 Point-Vortex Flow

abstract:
  The advection of passive tracers in a system of 4 identical point vortices is
studied when the motion of the vortices is chaotic. The phenomenon of
vortex-pairing has been observed and statistics of the pairing time is
computed. The distribution exhibits a power-law tail with exponent $\sim 3.6$
implying finite average pairing time. This exponents is in agreement with its
computed analytical estimate of 3.5. Tracer motion is studied for a chosen
initial condition of the vortex system. Accessible phase space is investigated.
The size of the cores around the vortices is well approximated by the minimum
inter-vortex distance and stickiness to these cores is observed. We investigate
the origin of stickiness which we link to the phenomenon of vortex pairing and
jumps of tracers between cores. Motion within the core is considered and
fluctuations are shown to scale with tracer-vortex distance $r$ as $r^{6}$. No
outward or inward diffusion of tracers are observed. This investigation allows
the separation of the accessible phase space in four distinct regions, each
with its own specific properties: the region within the cores, the reunion of
the periphery of all cores, the region where vortex motion is restricted and
finally the far-field region. We speculate that the stickiness to the cores
induced by vortex-pairings influences the long-time behavior of tracers and
their anomalous diffusion.

categories: physics.flu-dyn cond-mat nlin.CD physics.gen-ph


title: Pulsed Superconductivity Acceleration

abstract:
  The design of the proposed linear collider TESLA is based on 9-cell 1.3 GHz
superconducting niobium cavities, operated in pulsed mode. Within the framework
of an international collaboration the TESLA Test Facility (TTF) has been set up
at DESY, providing the infrastructure for cavity R&D towards higher gradients.
More than 60 nine-cell cavities were tested, accelerating gradients as high as
30 MV/m were measured. In the second production of TTF-cavities the average
gradient was measured to be 24.7 MV/m. Two modules, each containing eight
resonators, are presently used in the TTF-linac. These cavities are operated in
pulsed mode: 0.8 ms constant gradient with up to 10 Hz repetitions rate. We
will focus on two aspects: Firstly, the cavity fabrication and treatment is
discussed, allowing to reach high gradients. Latest results of single cell
cavities will be shown, going beyond 40 MV/m. Secondly, the pulsed mode
operation of superconducting cavities is reviewed. This includes Lorentz force
detuning, mechanical vibrations (microphonics) and rf field control. Both
topics meet the upcoming interest in superconducting proton linacs, like the sc
driver linac for SNS (Spallation Neutron Source).


title: Large Coherence Area Thin-Film Photonic Stop-Band Lasers

abstract:
  We demonstrate that the shift of the stop band position with increasing
oblique angle in periodic structures results in a wide transverse exponential
field distribution corresponding to strong angular confinement of the
radiation. The beam expansion follows an effective diffusive equation depending
only upon the spectral mode width. In the presence of gain, the beam cross
section is limited only by the size of the gain area. As an example of an
active periodic photonic medium, we calculate and measure laser emission from a
dye-doped cholesteric liquid crystal film.


title:
Large-Scale Simulation of Beam Dynamics in High Intensity Ion Linacs
  Using Parallel Supercomputers

abstract:
  In this paper we present results of using parallel supercomputers to simulate
beam dynamics in next-generation high intensity ion linacs. Our approach uses a
three-dimensional space charge calculation with six types of boundary
conditions. The simulations use a hybrid approach involving transfer maps to
treat externally applied fields (including rf cavities) and parallel
particle-in-cell techniques to treat the space-charge fields. The large-scale
simulation results presented here represent a three order of magnitude
improvement in simulation capability, in terms of problem size and speed of
execution, compared with typical two-dimensional serial simulations. Specific
examples will be presented, including simulation of the spallation neutron
source (SNS) linac and the Low Energy Demonstrator Accelerator (LEDA) beam halo
experiment.


title: A Plasma Model for RF Breakdown in Accelerator Structures

abstract:
  A plasma model is presented for the formation of ``cathode spots'' and
subsequent crater development near field emission sites on a copper surface in
the presence of a strong dc electric field. Adding to previously published
models, we propose that the two-stream plasma instability relates the plasma
density to its dimensions. Arguments are presented that suggest that the
formation and dynamics of such plasma spots are essentially the same phenomenon
for both dc and rf fields. A consequence for accelerating structures is that,
when such plasma spots are present, they erode the copper surface at a rate on
the order of 300 micrograms per Coulomb of ion bombardment current. This
erosion rate can have a measurable effect on the rf properties of an
accelerating structure after processing at high gradients for a few hundred
hours.


title: On Wolfgang Pauli's most important contributions to physics

abstract:
  After some brief biographical notes, Wolfgang Pauli's main contributions to
general relativity, quantum theory, quantum field theory, and elementary
particle physics are reviewed. A detailed description is given how Pauli
descovered - before the advent of the new quantum mechanics - his exclusion
principle.

categories: physics.hist-ph gr-qc hep-ph hep-th quant-ph


title: What is the Evans-Vigier Field?

abstract:
  We explain connections of the Evans-Vigier model with theories proposed
previously. The Comay's criticism is proved to be irrelevant.


title:
Dipole Septum Magnet in the Fast Kicker System for Multi-Axis Advanced
  Radiography

abstract:
  Here we present designs for a static septum magnet with two adjacent
apertures where ideally one aperture has a uniform dipole field and the other
zero field. Two designs are considered. One is a true septum magnet with a thin
layer of coils and materials separating the dipole field region from the null
field region. During the beam switching process, the intense electron beam will
spray across this material septum leading to concerns on beam control, vacuum
quality, radiation damage, etc. due to the lost particles. Therefore, another
configuration without a material septum is also considered. With this
configuration it is more difficult to achieve high field quality near the
transition region. Shaped shims are designed to limit the degradation of beam
quality (emittance growth). This approach is closely related to a previous
septum magnet design with two oppositely oriented dipole field regions
presented by the authors [1]. Simulations are performed to obtain the magnetic
field profile in both designs. A PIC simulation is used to transport a beam
slice consisting of several thousand particles through the magnet to estimate
emittance growth in the magnet due to field non-uniformity.


title: Relativistic angle-changes and frequency-changes

abstract:
  We generate a set of "relativistic" predictions for the relationship between
viewing angle and apparent frequency, for each of three different
non-transverse shift equations. We find that a detector aimed transversely (in
the lab frame) at a moving object should report a redshift effect with two out
of the three equations.


title: Modeling of an Inductive Adder Kicker Pulser for Darht-II

abstract:
  An all solid-state kicker pulser for a high current induction accelerator
(the Dual-Axis Radiographic Hydrodynamic Test facility DARHT-2) has been
designed and fabricated. This kicker pulser uses multiple solid state
modulators stacked in an inductive-adder configuration. Each modulator is
comprised of multiple metal-oxide-semiconductor field-effect transistors
(MOSFETs) which quickly switch the energy storage capacitors across a magnetic
induction core. Metglas is used as the core material to minimize loss. Voltage
from each modulator is inductively added by a voltage summing stalk and
delivered to a 50 ohm output cable. A lumped element circuit model of the
inductive adder has been developed to optimize the performance of the pulser.
Results for several stalk geometries will be compared with experimental data.


title: SLC Final Performance and Lessons

abstract:
  The Stanford Linear Collider (SLC) was the first prototype of a new type of
accelerator, the electron-positron linear collider. Many years of dedicated
effort were required to understand the physics of this new technology and to
develop the techniques for maximizing performance. Key issues were emittance
dilution, stability, final beam optimization and background control. Precision,
non-invasive diagnostics were required to measure and monitor the beams
throughout the machine. Beam-based feedback systems were needed to stabilize
energy, trajectory, intensity and the final beam size at the interaction point.
A variety of new tuning techniques were developed to correct for residual
optical or alignment errors. The final focus system underwent a series of
refinements in order to deliver sub-micron size beams. It also took many
iterations to understand the sources of backgrounds and develop the methods to
control them. The benefit from this accumulated experience was seen in the
performance of the SLC during its final run in 1997-98. The luminosity
increased by a factor of three to 3*10**30 and the 350,000 Z data sample
delivered was nearly double that from all previous runs combined.


title:
The Effect of an Under-Dense Plasma Density Gradient on the
  Backstreaming Ion Mechanism

abstract:
  The space charge limited emission of ions from a target in the focus of an
intense relativistic electron beam is studied analytically for the case of a
spatially varying target density profile. In particular, the emission in the
presence of an under-dense plasma shelf in contact with the solid density
target dramatically differs from the case of an abrupt solid-vacuum boundary.
It is found that an under-dense gradient scale length several times that of the
beam radius at the focus reduces the emission by at least an order of magnitude
over that to be expected from a solid-vacuum boundary.


title: Ion-Hose Instability in Long Pulse Induction Accelerators

abstract:
  The ion-hose (or fast-ion) instability sets limits on the allowable vacuum in
a long-pulse, high current accelerator. Beam-induced ionization of the
background gas leads to the formation of an ion channel which couples to the
transverse motion of the beam. The instability is studied analytically and
numerically for several ion frequency distributions. The effects of beam
envelope oscillations on the growth of the instability will be discussed. The
saturated non-linear growth of the instability is derived analytically and
numerically for two different ion frequency distributions.


title: Progress in Induction Linacs

abstract:
  This presentation will be a broad survey of progress in induction technology
over the past four years. Much work has been done on accelerators for
hydrodynamic test radiography and other applications. Solid-state pulsers have
been developed which can provide unprecedented flexibility and precision in
pulse format and accelerating voltage for both ion and electron induction
machines. Induction linacs can now be built which can operate with MHz
repetition rates. Solid-state technology has also made possible the development
of fast kickers for precision control of high current beams. New insulator
technology has been developed which will improve conventional induction linacs
in addition to enabling a new class of high gradient induction linacs.


title:
Design and optimization of tapered structure of near-field fiber probe
  based on FDTD simulation

abstract:
  The finite-difference time-domain method was employed to simulate light
propagation in tapered near-field fiber probes with small metal aperture. By
conducting large-volume simulations, including tapered metal-cladding waveguide
and connected optical fiber waveguide, we illustrated the coupling between
these guiding modes as well as the electric field distribution in the vicinity
of the aperture. The high collection efficiency of a double-tapered probe was
reproduced and was ascribed to the shortening of the cutoff region and the
efficient coupling to the guiding mode of the optical fiber. The dependence of
the efficiency on the tapered structure parameters was also examined.


title: Dynamics of Chemical Reactions: Open Equilibrium

abstract:
  Dynamic properties of chemical reactions and appropriate relationships for
open chemical equilibrium are discussed in approach of the chemical dynamics.
New way to calculate composition of chemical systems in open equilibrium, based
on the amended equation for the change of Gibbs' free energy, was exemplified
using reactions of cobalt double oxides with sulfur. Evaluated this way
equilibrium reaction extents had a good match with values found by direct
thermodynamic simulation. The developed method allows us to perform analysis of
complex chemical systems without coefficients of thermodynamic activity. In
cases when the coefficients are in need or just desirable, the method offers a
simple way to calculate them. Possible systems to apply method of chemical
dynamics are discussed.


title:
Connection between the Dielectric and the Ballistic Treatment of
  Collisional Absorption

abstract:
  In this work two important models of treating collisional absorption in a
laser driven plasma are compared, the dielectric and the ballistic model. We
will see that there exists a remarkable connection between these basic
approaches which could give a hint how to overcome the inherent limitations.
The approximations made in the models are not identical and lead to different
advantages and disadvantages. We notice that the dieletric model is able to
handle screening in a selfconsistent manner, but is limited to first order in
the electron-ion interaction. The ballistic model calculates the electron-ion
collision exactly in each order of the interaction, but has to introduce a
cut-off to incorporate screening effects. This means in the context of kinetic
theory that the electron-ion correlation has to be calculated either in random
phase or in ladder approximation, or, in other words, the linearized
Lenard-Balescu or Boltzmann collision term has to be used.


title: A path-integral approach to the collisional Boltzmann gas

abstract:
  Collisional effects are included in the path-integral formulation that was
proposed in one of our previous paper for the collisionless Boltzmann gas. In
calculating the number of molecules entering a six-dimensional phase volume
element due to collisions, both the colliding molecules and the scattered
molecules are allowed to have distributions; thus the calculation is done
smoothly and no singularities arise.


title:
Phase-coherent frequency measurement of the Ca intercombination line at
  657 nm with a Kerr-lens mode-locked femtosecond laser

abstract:
  The frequency of the Calcium ^3P_1--^1S_0 intercombination line at 657 nm is
phase-coherently measured in terms of the output of a primary cesium frequency
standard using an optical frequency comb generator comprising a sub-10 fs
Kerr-lens mode-locked Ti:Sapphire laser and an external microstructure fiber
for self-phase-modulation. The measured frequency of \nu_Ca = 455 986 240 494
276 Hz agrees within its relative uncertainty of 4 10^-13 with the values
previously measured with a conceptually different harmonic frequency chain and
with the value recommended for the realization of the SI unit of length.


title:
Nanosecond dynamics of a gallium mirror's light-induced reflectivity
  change

abstract:
  Transient pump-probe optical reflectivity measurements of the
nano/microsecond dynamics of a fully reversible, light-induced,
surface-assisted metallization of gallium interfaced with silica are reported.
The metallization leads to a considerable increase in the interface's
reflectivity when solid a-gallium is on the verge of melting. The reflectivity
change was found to be a cumulative effect that grows with light intensity and
pulse duration. The reflectivity relaxes back to that of alpha-gallium when the
excitation is withdrawn in a time that increases critically at gallium's
melting point. The effect is attributed to a non-thermal light-induced
structural phase transition.


title: Can zero-point phenomena truly be the origin of inertia?

abstract:
  A current approach to the problem of inertia suggests that the origin of the
inertial properties of matter is the interaction between matter and vacuum
electromagnetic zero-point radiation. Herein, it is shown that zero-point
phenomena can be treated as the origin of inertia only when one chooses to
ignore the mass-energy content of matter. In the absence of any physical basis
for such a choice, it is concluded that zero-point-induced forces must arise in
addition to the intrinsic inertial properties of ordinary matter.


title: Atomic antenna mechanism in HHG and ATI

abstract:
  This paper reviews recent development of the atomic antenna, a theoretical
framework which describes a number of laser-induced multiphoton phenomena in
atoms, in particular in High Harmonic Generation and in Above Threshold
Ionization. The paper presents a progress report made at the conference "Atoms,
molecules and quantum dots in laser fields: fundamental processes", PISA,
Italy, June 12-16, 2000


title: Spontaneous formation and stability of small GaP fullerenes

abstract:
  We report the spontaneous formation of a GaP fullerene cage in ab-initio
Molecular Dynamics simulations starting from a bulk fragment. A systematic
study of the geometric and electronic properties of neutral and ionized GaP
clusters suggests the stability of hetero-fullerenes formed by a compound with
zincblend bulk structure. We find that GaP fullerenes up to 28 atoms have high
symmetry, closed electronic shells, large HOMO-LUMO energy gaps and do not
dissociate when ionized. We compare our results for GaP with those obtained by
other groups for the corresponding BN clusters.


title:
Measurements of the instantaneous velocity difference and local velocity
  with a fiber-optic coupler

abstract:
  New optical arrangements with two single-mode input fibers and a fiber-optic
coupler are devised to measure the instantaneous velocity difference and local
velocity. The fibers and the coupler are polarization-preserving to guarantee a
high signal-to-noise ratio. When the two input fibers are used to collect the
scattered light with the same momentum transfer vector but from two spatially
separated regions in a flow, the obtained signals interfere when combined via
the fiber-optic coupler. The resultant light received by a photomultiplier tube
contains a cross-beat frequency proportional to the velocity difference between
the two measuring points. If the two input fibers are used to collect the
scattered light from a common scattering region but with two different momentum
transfer vectors, the resultant light then contains a self-beat frequency
proportional to the local velocity at the measuring point. The experiment shows
that both the cross-beat and self-beat signals are large and the standard laser
Doppler signal processor can be used to measure the velocity difference and
local velocity in real time. The new technique will have various applications
in the general area of fluid dynamics.

categories: physics.flu-dyn astro-ph cond-mat.soft physics.ins-det physics.optics


title: The Principle of Synergy and Isomorphic Units

abstract:
  A solution to the part and whole problem is presented in this paper by using
a complex mathematical representation that permits to define the Holon concept
as a Basic Unit System that remains itself in spite of complex operations such
as integration and derivation. This can be done because of the remarkable
isomorphic property of Euler Relation. We can then define a domain independent
both of the observer and the object, as within it, the object is embedded. We
will then be able to have a Quantum Mechanics solution without the "observer
drawback", as Karl R. Popper tried to find all his life but from the
philosophical point of view and which was Einstein main concern about QM too. A
unit that has always similar or identical structure or form, despite even
complex operations such as integration and derivation, is the ideal unit for
the new sciences of complexity or just the systems sciences too, where
structure or form, wholeness, organization, and complexity are main
requirements. A table for validating the results obtained is presented in case
of the pendulum formula.


title: What Future Expects Humanity After the Demographic Transition Time?

abstract:
  The variant of phenomenological theory of humankind future existence after
time of demographic transition based on treating the time of demographic
transition as a point of phase transition and taking into account an appearing
of the new phase of mankind is proposed. The theory based on physical
phenomenological theories of phase transitions and classical equations for
system predatory-preys for two phases of mankind, take into account assumption
about a multifractal nature of the set of number of people in temporal axis and
contains control parameters. The theory includes scenario of destroying of
existent now human population by new phase of humanity and scenario of old and
new phases co-existence. In particular cases when the new phase of mankind is
absent the equations of theory may be formulated as equations of Kapitza,
Foerster, Hoerner, Kobelev and Nugaeva, Johansen and Sornette phenomenological
theories of growth of mankind.


title:
Continuous-wave Doppler-cooling of hydrogen atoms with two-photon
  transitions

abstract:
  We propose and analyze the possibility of performing two-photon
continuous-wave Doppler-cooling of hydrogen atoms using the 1S-2S transition.
"Quenching" of the 2S level (by coupling with the 2P state) is used to increase
the cycling frequency, and to control the equilibrium temperature. Theoretical
and numerical studies of the heating effect due to Doppler-free two-photon
transitions evidence an increase of the temperature by a factor of two. The
equilibrium temperature decreases with the effective (quenching dependent)
width of the excited state and can thus be adjusted up to values close to the
recoil temperature.


title:
Photoabsorption spectra in the continuum of molecules and atomic
  clusters

abstract:
  We present linear response theories in the continuum capable of describing
photoionization spectra and dynamic polarizabilities of finite systems with no
spatial symmetry. Our formulations are based on the time-dependent local
density approximation with uniform grid representation in the three-dimensional
Cartesian coordinate. Effects of the continuum are taken into account either
with a Green's function method or with a complex absorbing potential in a
real-time method. The two methods are applied to a negatively charged cluster
in the spherical jellium model and to some small molecules (silane, acetylene
and ethylene).


title: Quantum SuperStrings and Quantized Fractal Space Time

abstract:
  Though Quantum SuperString Theory has shown promise, there are some puzzling
features like the extra dimensions, which are curled up in the Kaluza-Klein
sense. On the other hand a recent formulation of what may be called Quantized
Fractal Space Time leads to a surprising interface with QSS - we deal with the
Planck length, the same number of extra dimensions and an identical
non-commutative geometry. It is shown that this is not accidental. On the
contrary it gives us insight into the otherwise inexplicable features of QSS.


title: A macroscopic approach to creating exotic matter

abstract:
  Herein the Casimir effect is used to present a simple macroscopic view on
creating exotic matter. The energy arising between two nearly perfectly
conducting parallel plates is shown to become increasingly negative as the
plate separation is reduced. It is proposed that the Casimir energy appears
increasingly negative simply because the vacuum electromagnetic zero-point
field performs positive work in pushing the plates together, transforming field
energy into kinetic energy of the plates. Next, the inertial properties of
exotic matter are considered. The parallel plates of the Casimir system are
replaced with an enclosed cavity of identical dimensions that is subjected to
an external force. It is found that zero-point radiation exerts an inertial
force on the cavity in opposition to the external force. This ultimately leads
to the conclusion that the inertial properties of exotic matter are identical
to the inertial properties of ordinary matter.


title:
Breit interaction correction to the hyperfine constant of an external
  s-electron in many-electron atom

abstract:
  Correction to the hyperfine constant $A$ of an external s-electron in
many-electron atom caused by the Breit interaction is calculated analytically:
$\delta A/A =0.68 Z\alpha^2$. Physical mechanism for this correction is
polarization of the internal electronic shells (mainly $1s^2$ shell) by the
magnetic field of the external electron. This mechanism is similar to the
polarization of vacuum considered by Karplus and Klein long time ago. The
similarity is the reason why in both cases (Dirac sea polarization and internal
atomic shells polarization) the corrections have the same dependence on the
nuclear charge and fine structure constant.
  In conclusion we also discuss $Z\alpha^2$ corrections to the parity violation
effects in atoms.


title:
A quasi classical approach to fully differential ionization cross
  sections

abstract:
  A classical approximation to time dependent quantum mechanical scattering in
the M\o{}ller formalism is presented. Numerically, our approach is similar to a
standard Classical-Trajectory-Monte-Carlo calculation. Conceptually, however,
our formulation allows one to release the restriction to stationary initial
distributions. This is achieved by a classical forward-backward propagation
technique. As a first application and for comparison with experiment we present
fully differential cross sections for electron impact ionization of atomic
hydrogen in the Erhardt geometry.


title: Number counts against K-corrections

abstract:
  This paper has been withdrawn by the author due to the presented idea is
wrong.


title: Pathways to double ionization of atoms in strong fields

abstract:
  We discuss the final stages of double ionization of atoms in a strong
linearly polarized laser field within a classical model. We propose that all
trajectories leading to non-sequential double ionization pass close to a saddle
in phase space which we identify and characterize. The saddle lies in a two
degree of freedom subspace of symmetrically escaping electrons. The
distribution of longitudinal momenta of ions as calculated within the subspace
shows the double hump structure observed in experiments. Including a symmetric
bending mode of the electrons allows us to reproduce the transverse ion
momenta. We discuss also a path to sequential ionization and show that it does
not lead to the observed momentum distributions.


title: A sandpile model with tokamak-like enhanced confinement phenomenology

abstract:
  Confinement phenomenology characteristic of magnetically confined plasmas
emerges naturally from a simple sandpile algorithm when the parameter
controlling redistribution scalelength is varied. Close analogues are found for
enhanced confinement, edge pedestals, and edge localised modes (ELMs), and for
the qualitative correlations between them. These results suggest that tokamak
observations of avalanching transport are deeply linked to the existence of
enhanced confinement and ELMs.


title: Comments on Superluminal Laser Pulse Propagation

abstract:
  Researchers claim to have observed superluminal (faster than light)
propagation of a laser pulse in a gain medium by a new mechanism in which there
is no distortion of the pulse [Nature, 406, 277 (2000)]. Our analysis shows
that the observed mechanism is due to pulse distortion arising from a
differential gain effect and should not be viewed as superluminal propagation.


title:
The decay of plane wave pulses with complex structure in a nonlinear
  dissipative medium

abstract:
  Nonlinear plane acoustic waves propagating through a fluid are studied using
Burgers' equation with finite viscosity. The evolution of a simple N-pulse with
regular and random initial amplitude and of pulses with monochromatic and noise
carrier is considered. In the latter case the initial pulses are characterized
by two length scales. The length scale of the modulation function is much
greater than the period or the length scale of the carrier. With increasing
time the initial pulses are deformed and shocks appear. The finite viscosity
leads to a finite shock width, which does not depend on the fine structure of
the initial pulse and is fully determined by the shock position in the zero
viscosity limit. The other effect of nonzero viscosity is the shift of the
shock position from the position at zero viscosity. This shift, as well as the
linear time, at which the nonlinear stage of evolution changes to the linear
stage, depends on the fine structure of the initial pulse. It is also shown
that the nonlinearity of the medium leads to generation of a nonzero mean field
from an initial random field with zero mean value. The relative fluctuation of
the field is investigated both at the nonlinear and the linear stage.


title:
Comment on ``Do Zero-energy Solutions of Maxwell Equations Have the
  Physical Origin Suggested by A. E. Chubykalo?" by V.V. Dvoeglazov

abstract:
  This is the answer to objections put forth in Proceedings of the Zacatecas
Workshop "Lorentz Group, CPT and Neutrinos" (World Scientific, Singapore,
2000), pp. 335-341.


title: Coulomb Interaction Does Not Spread Instantaneously

abstract:
  The experiment is described which shows that Coulomb interaction spreads with
a limit velocity and thus this kind of interaction cannot be considered as so
called "instantaneous action at a distance".


title:
Comment on ``Dependence of Gravitational Action on Chemical Composition:
  New Series of Experiments" by M. Nanni [Apeiron v. 7, No. 3-4, pp. 195-201]

abstract:
  In our comment we show that the application of appropriate statistical
methods to the results of the author proves that the author in his article has
not been able to reach his goal.


title:
Resummation of the Divergent Perturbation Series for a Hydrogen Atom in
  an Electric Field

abstract:
  We consider the resummation of the perturbation series describing the energy
displacement of a hydrogenic bound state in an electric field (known as the
Stark effect or the LoSurdo-Stark effect), which constitutes a divergent formal
power series in the electric field strength. The perturbation series exhibits a
rich singularity structure in the Borel plane. Resummation methods are
presented which appear to lead to consistent results even in problematic cases
where isolated singularities or branch cuts are present on the positive and
negative real axis in the Borel plane. Two resummation prescriptions are
compared: (i) a variant of the Borel-Pade resummation method, with an
additional improvement due to utilization of the leading renormalon poles (for
a comprehensive discussion of renormalons see [M. Beneke, Phys. Rep. vol. 317,
p. 1 (1999)]), and (ii) a contour-improved combination of the Borel method with
an analytic continuation by conformal mapping, and Pade approximations in the
conformal variable. The singularity structure in the case of the LoSurdo-Stark
effect in the complex Borel plane is shown to be similar to (divergent)
perturbative expansions in quantum chromodynamics.


title: Maximally Informative Statistics

abstract:
  In this paper we propose a Bayesian, information theoretic approach to
dimensionality reduction. The approach is formulated as a variational principle
on mutual information, and seamlessly addresses the notions of sufficiency,
relevance, and representation. Maximally informative statistics are shown to
minimize a Kullback-Leibler distance between posterior distributions.
Illustrating the approach, we derive the maximally informative one dimensional
statistic for a random sample from the Cauchy distribution.


title: Hydration of methanol in water. A DFT-based molecular dynamics study

abstract:
  We studied the hydration of a single methanol molecule in aqueous solution by
first-principle DFT-based molecular dynamics simulation. The calculations show
that the local structural and short-time dynamical properties of the water
molecules remain almost unchanged by the presence of the methanol, confirming
the observation from recent experimental structural data for dilute solutions.
We also see, in accordance with this experimental work, a distinct shell of
water molecules that consists of about 15 molecules. We found no evidence for a
strong tangential ordering of the water molecules in the first hydration shell.


title: On Optimality in Auditory Information Processing

abstract:
  We study limits for the detection and estimation of weak sinusoidal signals
in the primary part of the mammalian auditory system using a stochastic
Fitzhugh-Nagumo (FHN) model and an action-reaction model for synaptic
plasticity. Our overall model covers the chain from a hair cell to a point just
after the synaptic connection with a cell in the cochlear nucleus. The
information processing performance of the system is evaluated using so called
phi-divergences from statistics which quantify a dissimilarity between
probability measures and are intimately related to a number of fundamental
limits in statistics and information theory (IT). We show that there exists a
set of parameters that can optimize several important phi-divergences
simultaneously and that this set corresponds to a constant quiescent firing
rate (QFR) of the spiral ganglion neuron. The optimal value of the QFR is
frequency dependent but is essentially independent of the amplitude of the
signal (for small amplitudes). Consequently, optimal processing according to
several standard IT criteria can be accomplished for this model if and only if
the parameters are ``tuned'' to values that correspond to one and the same QFR.
This offers a new explanation for the QFR and can provide new insight into the
role played by several other parameters of the peripheral auditory system.


title:
A Particle Field Theorist's Lectures on Supersymmetric, Non-Abelian
  Fluid Mechanics and d-Branes

abstract:
  This monograph is derived from a series of six lectures I gave at the Centre
de Recherches Mathematiques in Montreal, in March and June 2000, while titulary
of the Aisenstadt Chair.


title: Bunch Length Measurements at the ATF Damping Ring in April 2000

abstract:
  This report presents bunch length and energy spread measurements performed in
April 2000 at the ATF Damping Ring, at KEK. Measurements were performed with
the beam on and then off the linear (difference) coupling resonance. Due to
strong intra-beam scattering in the ATF ring, the results depended strongly on
the coupling.


title:
Coordinate-space approach to the bound-electron self-energy: Self-Energy
  screening calculation

abstract:
  The self-energy screening correction is evaluated in a model in which the
effect of the screening electron is represented as a first-order perturbation
of the self energy by an effective potential. The effective potential is the
Coulomb potential of the spherically averaged charge density of the screening
electron. We evaluate the energy shift due to a $1s_{1/2}$, $2s_{1/2}$,
$2p_{1/2}$, or $2p_{3/2}$ electron screening a $1s_{1/2}$, $2s_{1/2}$,
$2p_{1/2}$, or $2p_{3/2}$ electron, for nuclear charge Z in the range $5 \le
Z\le 92$. A detailed comparison with other calculations is made.


title: Dynamic fitness landscapes: Expansions for small mutation rates

abstract:
  We study the evolution of asexual microorganisms with small mutation rate in
fluctuating environments, and develop techniques that allow us to expand the
formal solution of the evolution equations to first order in the mutation rate.
Our method can be applied to both discrete time and continuous time systems.
While the behavior of continuous time systems is dominated by the average
fitness landscape for small mutation rates, in discrete time systems it is
instead the geometric mean fitness that determines the system's properties. In
both cases, we find that in situations in which the arithmetic (resp.
geometric) mean of the fitness landscape is degenerate, regions in which the
fitness fluctuates around the mean value present a selective advantage over
regions in which the fitness stays at the mean. This effect is caused by the
vanishing genetic diffusion at low mutation rates. In the absence of strong
diffusion, a population can stay close to a fluctuating peak when the peak's
height is below average, and take advantage of the peak when its height is
above average.

categories: physics.bio-ph cond-mat.soft nlin.AO q-bio.PE


title:
Deterministic chaos, fractals and quantumlike mechanics in atmospheric
  flows

abstract:
  The complex spaciotemporal patterns of atmospheric flows that result from the
cooperative existence of fluctuations ranging in size from millimetres to
thousands of kilometres are found to exhibit long-range spacial and temporal
correlations. These correlations are manifested as the self-similar fractal
geometry of the global cloud cover pattern and the inverse power-law form for
the atmospheric eddy energy spectrum. Such long-range spaciotemporal
correlations are ubiquitous in extended natural dynamical systems and are
signatures of deterministic chaos or self-organized criticality. In this paper,
a cell dynamical system model for atmospheric flows is developed by
consideration of microscopic domain eddy dynamical processes. This
nondeterministic model enables formulation of a simple closed set of governing
equations for the prediction and description of observed atmospheric flow
structure characteristics as follows. The strange-attractor design of the field
of deterministic chaos in atmospheric flows consists of a nested continuum of
logarithmic spiral circulations that trace out the quasi-periodic Penrose
tiling pattern, identified as the quasi-crystalline structure in condensed
matter physics. The atmospheric eddy energy structure follows laws similar to
quantum mechanical laws. The apparent wave-particle duality that characterize
quantum mechanical laws is attributed to the bimodal phenomenological form of
energy display in the bidirectional energy flow that is intrinsic to eddy
circulations, e.g., formation of clouds in updrafts and dissipation of clouds
in downdrafts that result in the observed discrete cellular geometry of cloud
structure.


title: Magnetic Field Saturation in the Riga Dynamo Experiment

abstract:
  After the dynamo experiment in November 1999 had shown magnetic field
self-excitation in a spiraling liquid metal flow, in a second series of
experiments emphasis was placed on the magnetic field saturation regime as the
next principal step in the dynamo process. The dependence of the strength of
the magnetic field on the rotation rate is studied. Various features of the
saturated magnetic field are outlined and possible saturation mechanisms are
discussed.

categories: physics.flu-dyn astro-ph physics.geo-ph physics.plasm-ph


title:
Computer simulation approach to reliability and accuracy in EXAFS
  structural determinations

abstract:
  The frequency distribution of different parameters of an EXAFS spectrum can
be directly sampled by analysing a population of simulated spectra produced by
adding computer-generated noise to a reference pattern. The procedure gives
statistical estimators of the parameter obtained with different data processing
strategies to test the performance of a strategy, to evaluate the bias
introduced by random noise, and to clarify the amount of information actually
contained in an experimental spectrum. Examples are given for the two simple
local structures of an Ag atom sorrounded by two oxygens or by six iodines.


title: Generalized Radial Equations in a Quantum N-Body Problem

abstract:
  We demonstrate how to separate the rotational degrees of freedom in a quantum
N-body problem completely from the internal ones. It is shown that any common
eigenfunction of the total orbital angular momentum ($\ell$) and the parity in
the system can be expanded with respect to $(2\ell+1)$ base-functions, where
the coefficients are the functions of the internal variables. We establish
explicitly the equations for those functions, called the generalized radial
equations, which are $(2\ell+1)$ coupled partial differential equations
containing only $(3N-6)$ internal variables.


title: A Physical Origin for Mass and Charge

abstract:
  This article proposes a concept called Condensed Electromagnetic Radiation
(CER) as the electromagnetic origin of mass particles. An overwhelming amount
of experimental evidence is consistent with the CER concept as a fundamental
explanation for the physical properties of mass particles. Among many others
cited, two well-established physical phenomena offer especially compelling
evidence: parametric down conversion of photons, and generation of leptons and
quarks.


title: Thermodynamics of Substances with Negative Thermal Expansion Coefficient

abstract:
  The 1st law of thermodynamics for heat exchange is dQ=dU+PdV. According to K.
Martinas etc., J. Non-Equil. Thermod. 23 (4), 351-375 (1988), for substances
with negative thermal expansion coefficient, P in this law is negative. In the
present paper it has been shown that P for such substances is positive but the
sign before P must be minus not plus: dQ=dU-PdV.


title: The Law of Conservation of Energy in Chemical Reactions

abstract:
  Earlier it has been supposed that the law of conservation of energy in
chemical reactions has the following form: DU=DQ-PDV+SUM(muiDN) In the present
paper it has been proved by means of the theory of ordinary differential
equations that in the biggest part of the chemical reactions it must have the
following form: DU=DQ+PDV+SUM(muiDN) The result obtained allows to explain a
paradox in chemical thermodynamics: the heat of chemical processes measured by
calorimetry and by the Vant-Hoff equation differs very much from each other.
The result is confirmed by many experiments.


title:
Maple procedures in teaching the canonical formalism of general
  relativity

abstract:
  We present some Maple procedures using the GrTensorII package for teaching
purposes in the study of the canonical version of the general relativity based
on the ADM formalism


title: The Heats of Reactions. Calorimetry and Van't-Hoff. 1

abstract:
  It has been supposed that the law of conservation of energy in chemical
reactions has the following form: dU=dQ-PdV+SUM Earlier the author has shown
that for the biggest part of reactions it must have the following form:
dU=dQ+PdV+SUM In the present paper this result is confirmed by other
experiments.


title: Nonlinear $\delta f$ Method for Beam-Beam Simulation

abstract:
  We have developed an efficacious algorithm for simulation of the beam-beam
interaction in synchrotron colliders based on the nonlinear $\delta f$ method,
where $\delta f$ is the much smaller deviation of the beam distribution from
the slowly evolving main distribution $f_0$. In the presence of damping and
quantum fluctuations of synchrotron radiation it has been shown that the slowly
evolving part of the distribution function satisfies a Fokker-Planck equation.
Its solution has been obtained in terms of a beam envelope function and an
amplitude of the distribution, which satisfy a coupled system of ordinary
differential equations. A numerical algorithm suited for direct code
implementation of the evolving distributions for both $\delta f$ and $f_0$ has
been developed. Explicit expressions for the dynamical weights of
macro-particles for $\delta f$ as well as an expression for the slowly changing
$f_0$ have been obtained.


title: External-field shifts of the 199Hg+ optical frequency standard

abstract:
  Frequency shifts of the ^199Hg^+ 5d^10 6s ^2S_1/2 (F=0, M_F=0) to 5d^9 6s^2
^2D_5/2 (F=2, M_F=0) electric-quadrupole transition at 282 nm due to external
fields are calculated, based on a combination of measured atomic parameters and
ab initio calculations. This transition is under investigation as an optical
frequency standard. The perturbations calculated are the quadratic Zeeman
shift, the scalar and tensor quadratic Stark shifts, and the interaction
between an external electric field gradient and the atomic quadrupole moment.
The quadrupole shift is likely to be the most difficult to evaluate in a
frequency standard and may have a magnitude of about 1 Hz for a single ion in a
Paul trap.


title: Vortex tubes in velocity fields of laboratory isotropic turbulence

abstract:
  The streamwise and transverse velocities are measured simultaneously in grid
turbulence at Reynolds numbers 100-300. We extract typical intermittency
patterns, which are consistent with velocity profiles of Burgers and Lamb-Oseen
vortices. The radii of these vortex tubes are estimated to be several of the
Kolmogorov length.


title:
Electromagnetic energy penetration in the self-induced transparency
  regime of relativistic laser-plasma interactions

abstract:
  Two scenarios for the penetration of relativistically intense laser radiation
into an overdense plasma, accessible by self-induced transparency, are
presented. For supercritical densities less than 1.5 times the critical one,
penetration of laser energy occurs by soliton-like structures moving into the
plasma. At higher background densities laser light penetrates over a finite
length only, that increases with the incident intensity. In this regime
plasma-field structures represent alternating electron layers separated by
about half a wavelength by depleted regions.


title: The Nuclear Force is Gravitation. Was Einstein Right?

abstract:
  I combine the effects of Planck length, general relativity and Newtonian
gravity in one equation, to come up with a semi-classical model of gravity in
the form of deviation from Newtonian gravity. Einstein explained nuclear forces
in terms of gravity (Ref. 2). This reference is explicit in expressing
Einstein's attempts and describes them as misguided. My model shows Einstein
was not misguided in his attempts to explain nuclear forces in terms of
gravity. My model shows just the contrary. I use Planck length as what it is:
minimum distance that makes any sense. I make a subatomic distinction between
mass and space, a lesson learned from general relativity. General relativity is
about mass telling space how to curve and space telling mass how to move.
Unlike string theory, I use no imaginary dimensions. My model predicts maximum
nuclear force as the limit of gravitation and clearly yields Newtonian gravity
at a macroscopic scale in an unprecedented and consistent manner: Good-by to
quantum gravity.
  I am combining Newton, Planck and Einstein and to predict a limit of gravity
as Chandrashekhar did to predict his limit.


title: Wannier-Stark states of a quantum particle in 2D lattices

abstract:
  A simple method of calculating the Wannier-Stark resonances in 2D lattices is
suggested. Using this method we calculate the complex Wannier-Stark spectrum
for a non-separable 2D potential realized in optical lattices and analyze its
general structure. The dependence of the lifetime of Wannier-Stark states on
the direction of the static field (relative to the crystallographic axis of the
lattice) is briefly discussed.


title:
A variational Monte Carlo calculation of dynamic multipole
  polarizabilities and van der Waals coefficients of the PsH system

abstract:
  The first three dynamic multipole polarizabilities for the ground state of
hydrogen, helium, hydride ion, and positronium hydride PsH have been computed
using the variational Monte Carlo (VMC) method and explicitly correlated wave
functions. Results for the static dipole polarizability by means of the
diffusion Monte Carlo (DMC) method and the finite field approach show the VMC
results to be quite accurate. From these dynamic polarizabilities van der Waals
dispersion coefficients for the interaction of PsH with ordinary electronic
systems can be computed, allowing one to predict the dispersion energy for the
interaction between PsH and less exotic atoms and molecules.


title: Stability and production of positron-diatomic molecule complexes

abstract:
  The energies at geometries close to the equilibrium for the e$^+$BeO and
e$^+$LiF ground states were computed by means of diffusion Monte Carlo
simulations. These results allow us to predict the equilibrium geometries and
the vibrational frequencies for these exotic systems,and to discuss their
stability with respect to the various dissociation channels. Since the
adiabatic positron affinities were found to be smaller than the dissociation
energies for both complexes, we propose these two molecules as possible
candidates in the challenge to produce and detect stable positron-molecule
systems.


title: Optimal Recovery of Local Truth

abstract:
  Probability mass curves the data space with horizons. Let f be a multivariate
probability density function with continuous second order partial derivatives.
Consider the problem of estimating the true value of f(z) > 0 at a single point
z, from n independent observations. It is shown that, the fastest possible
estimators (like the k-nearest neighbor and kernel) have minimum asymptotic
mean square errors when the space of observations is thought as conformally
curved. The optimal metric is shown to be generated by the Hessian of f in the
regions where the Hessian is definite. Thus, the peaks and valleys of f are
surrounded by singular horizons when the Hessian changes signature from
Riemannian to pseudo-Riemannian. Adaptive estimators based on the optimal
variable metric show considerable theoretical and practical improvements over
traditional methods. The formulas simplify dramatically when the dimension of
the data space is 4. The similarities with General Relativity are striking but
possibly illusory at this point. However, these results suggest that
nonparametric density estimation may have something new to say about current
physical theory.


title:
Role and meaning of subjective probability: some comments on common
  misconceptions

abstract:
  Criticisms of so called `subjective probability' come on the one hand from
those who maintain that probability in physics has only a frequentistic
interpretation, and, on the other, from those who tend to `objectivise'
Bayesian theory, arguing, e.g., that subjective probabilities are indeed based
`only on private introspection'. Some of the common misconceptions on
subjective probability will be commented upon in support of the thesis that
coherence is the most crucial, universal and `objective' way to assess our
confidence on events of any kind.


title: An Optical Trap for Collisional Studies on Cold Fermionic Potassium

abstract:
  We report on trapping of fermionic 40K atoms in a red-detuned standing-wave
optical trap, loaded from a magneto-optical trap. Typically, 10^6 atoms are
loaded at a density of 10^12 cm^-3 and a temperature of 65 microK, and trapped
for more than 1 s. The optical trap appears to be the proper environment for
performing collisional measurements on the cold atomic sample. In particular we
measure the elastic collisional rate by detecting the rethermalization
following an intentional parametric heating of the atomic sample. We also
measure the inelastic two-body collisional rates for unpolarized atoms in the
ground hyperfine states, through detection of trap losses.


title:
Optimization of ground and excited state wavefunctions and van der Waals
  clusters

abstract:
  A quantum Monte Carlo method is introduced to optimize excited state trial
wavefunctions. The method is applied in a correlation function Monte Carlo
calculation to compute ground and excited state energies of bosonic van der
Waals clusters of upto seven particles. The calculations are performed using
trial wavefunctions with general three-body correlations.


title: The second "Einstein paradox"

abstract:
  Time invariance problem of a photon absorption process in atoms and molecules
is discussed.


title: The No-sticking Effect in Ultra-cold Collisions

abstract:
  We provide the theoretical basis for understanding the phenomenon in which an
ultra cold atom incident on a possibly warm target will not stick, even in the
large $n$ limit where $n$ is the number of internal degrees of freedom of the
target. Our treatment is non-perturbative in which the full many-body problem
is viewed as a scattering event purely within the context of scattering theory.
The question of sticking is then simply and naturally identified with the
formation of a long lived resonance. One crucial physical insight that emerges
is that the many internal degrees of freedom serve to decohere the incident one
body wavefunction, thus upsetting the delicate interference process necessary
to form a resonance in the first place. This is the physical reason for not
sticking.


title:
Transition from reflection to sticking in ultracold atom-surface
  scattering

abstract:
  In paper I (physics/0010068) entitled "The No-sticking Effect in Ultra-cold
Collisions", we showed that under very general circumstances, atoms approaching
a surface will not stick as its incoming energy approaches zero. This is true
of either warm or cold surfaces. Here we explore the transition region from non
sticking to sticking as energy is increased. The key to understanding the
transition region is the WKB approximation and the nature of its breakdown.
Simple rules for understanding the rollover to higher energy, post-threshold
behavior, including analytical formulae for some asymptotic forms of the
attractive potential are presented. We discuss a practical example of
atom-surface pair in various substrate geometries. We also discuss the case of
low energy scattering from clusters.


title:
Quantum Fluctuations of the Gravitational Field and Propagation of
  Light: a Heuristic Approach

abstract:
  Quantum gravity is quite elusive at the experimental level; thus a lot of
interest has been raised by recent searches for quantum gravity effects in the
propagation of light from distant sources, like gamma ray bursters and active
galactic nuclei, and also in earth-based interferometers, like those used for
gravitational wave detection. Here we describe a simple heuristic picture of
the quantum fluctuations of the gravitational field that we have proposed
recently, and show how to use it to estimate quantum gravity effects in
interferometers.


title:
Coherent time evolution of highly excited Rydberg states in pulsed
  electric field: Opening a stringent way to selectively field-ionize the
  highly excited states

abstract:
  Coherent time evolution of highly excited Rydberg states in Rb (98 < n < 150)
under pulsed electric field in high slew-rate regime was investigated with the
field ionization detection. The electric field necessary to ionize the Rydberg
states was found to take discrete values successively depending on the slew
rate. Specifically the slew-rate dependence of the ionization field varies with
the quantum defect value of the states, i.e. with the energy position of the
states relative to the adjacent manifold. This discrete transitional behavior
of the ionization field observed for the first time is considered to be a
manifestation of the strong coherence effect in the time evolution of the
Rydberg states in pulsed electric field and opens a new effective way to
stringently select a low-l state from the nearby states by field ionization.


title:
On the four dimensional Conformal Anomaly, Fractal Spacetime and the
  Fine Structure Constant

abstract:
  Antoniadis, Mazur and Mottola (AMM) two years ago computed the intrinsic
Hausdorff dimension of spacetime at the infrared fixed point of the quantum
conformal factor in 4D Gravity. The fractal dimension was determined by the
coefficient of the Gauss-Bonnet topological term associated with the conformal
gravitational anomaly and was found to be greater than 4. It is explicitly
shown how one can relate the value of the Hausdorff dimension computed by AMM
to the universal dimensional fluctuation of spacetime $\epsilon $ given by
$\phi^3/2$, where $\phi$ is the Golden Mean $0.618..$. Based on the infrared
scaling limit of the theory and using recent Renormalization Group arguments by
El Naschie, we conjecture that the unknown coefficient $Q^2$, associated with
the four dimensional gravitational conformal anomaly, could be precisely equal
to the inverse fine structure constant values ranging between $137.036 $ and
137.081. Our results generate decimal digits up to any $arbitrary$ number.


title: Is the Basic Unit System a String?

abstract:
  The main aim of this paper is to present an overview of the need of a new way
of coping the fundamental equations of physics, see the references. Our main
aim is to build a new metrics in which both time and space are included, but in
some sort of minkowskian union of the two and in such a way that that union
preserves an independent reality, and where energy, can be taken as the real
fundamental issue of that metrics, instead of the particle concept. A departure
from General Theory of Relativity is clear, but then the BUS concept behaves
itself as a fundamental string.


title: Transverse redshift effects without special relativity

abstract:
  Transverse redshift effects are sometimes presented as being unique to
special relativity (the "transverse Doppler effect"). We argue that if the
detector is aimed at 90 degrees in the laboratory frame, most theories will
predict a redshifted frequency at the detector, although these predictions can
be concealed by specifying that angles should be defined in a frame /other/
than the laboratory frame. These redshifts are often stronger than special
relativity's predictions. We list some of the situations in which
lab-transverse redshifts would be expected.


title: The Heats of Dilution. Calorimetry and Van't-Hoff

abstract:
  Earlier it has been found that there is a big difference between heats of
dilution measured by calorimetry and by the Van't-Hoff equation. In the present
paper a reason for that is proposed. Experimental data for dilution of benzene
and n-hexane in water were used.


title: Optical interpretation of special relativity and quantum mechanics

abstract:
  The present work shows that through a suitable change of variables
relativistic dynamics can be mapped to light propagation in a non-homogeneous
medium. A particle's trajectory through the modified space-time is thus
formally equivalent to a light ray and can be derived from a mechanical
equivalent of Fermat's principle. The similarities between light propagation
and mechanics are then extended to quantum mechanics, showing that relativistic
quantum mechanics can be derived from a wave equation in modified space-time.
Non-relativistic results, such as de Broglie's wavelength, Schroedinger
equation and uncertainty principle are shown to be direct consequences of the
theory and it is argued that relativistic conclusions are also possible.


title: Progress in the Next Linear Collider Design

abstract:
  An electron/positron linear collider with a center-of-mass energy between 0.5
and 1 TeV would be an important complement to the physics program of the LHC in
the next decade. The Next Linear Collider (NLC) is being designed by a US
collaboration (FNAL, LBNL, LLNL, and SLAC) which is working closely with the
Japanese collaboration that is designing the Japanese Linear Collider (JLC).
The NLC main linacs are based on normal conducting 11 GHz rf. This paper will
discuss the technical difficulties encountered as well as the many changes that
have been made to the NLC design over the last year. These changes include
improvements to the X-band rf system as well as modifications to the injector
and the beam delivery system. They are based on new conceptual solutions as
well as results from the R&D programs which have exceeded initial
specifications. The net effect has been to reduce the length of the collider
from about 32 km to 25 km and to reduce the number of klystrons and modulators
by a factor of two. Together these lead to significant cost savings.


title:
Studies of Beam Optics and Scattering in the Next Linear Collider
  Post-Linac Collimation System

abstract:
  We present a new conceptual and optical design for the Next Linear Collider
post-linac collimation system. Energy collimation and passive protection
against off-energy beams are achieved in a system with large horizontal
dispersion and vertical betatron functions. Betatron collimation is performed
in a relatively low-beta (FODO-like) lattice in which only thin spoilers
intercept particles near the beam core, while thick absorbers maintain a large
stay-clear from the beam. Two possible schemes for the spoilers are considered:
one in which the spoilers are capable of tolerating a certain number of
damaging interceptions per collider run ("consumable" spoilers), and one in
which the spoilers are potentially damaged on every machine pulse and are
self-repairing ("renewable" spoilers). The collimation efficiency of the system
is evaluated, considering both halo particles which are rescattered into the
beam and muon secondaries which are passed to the interaction region. We
conclude that the new design is a promising candidate for the NLC post-linac
system.


title:
Description of Vorticity by Grassmann Variables and an Extension to
  Supersymmetry

abstract:
  In this paper, particle physics concepts are blended into a field theory for
macroscopic phenomena: Fluid mechanics is enhanced by anticommuting Grassmann
variables to describe vorticity, while an additional interaction for the
Grassmann variables leads to supersymmetric fluid mechanics.


title: How can an electron interact with itself?

abstract:
  An electron may interact with itself through the vacuum polarization induced
in the vacuum electrons due to the electron.


title:
Capacity of multivariate channels with multiplicative noise: I.Random
  matrix techniques and large-N expansions for full transfer matrices

abstract:
  We study memoryless, discrete time, matrix channels with additive white
Gaussian noise and input power constraints of the form $Y_i = \sum_j H_{ij} X_j
+ Z_i$, where $Y_i$ ,$X_j$ and $Z_i$ are complex, $i=1..m$, $j=1..n$, and $H$
is a complex $m\times n$ matrix with some degree of randomness in its entries.
The additive Gaussian noise vector is assumed to have uncorrelated entries. Let
$H$ be a full matrix (non-sparse) with pairwise correlations between matrix
entries of the form $ E[H_{ik} H^*_{jl}] = {1\over n}C_{ij} D_{kl} $, where
$C$,$D$ are positive definite Hermitian matrices. Simplicities arise in the
limit of large matrix sizes (the so called large-N limit) which allow us to
obtain several exact expressions relating to the channel capacity. We study the
probability distribution of the quantity $ f(H) = \log \det (1+P H^{\dagger}S
H) $. $S$ is non-negative definite and hermitian, with $Tr S=n$. Note that the
expectation $E[f(H)]$, maximised over $S$, gives the capacity of the above
channel with an input power constraint in the case $H$ is known at the receiver
but not at the transmitter. For arbitrary $C$,$D$ exact expressions are
obtained for the expectation and variance of $f(H)$ in the large matrix size
limit. For $C=D=I$, where $I$ is the identity matrix, expressions are in
addition obtained for the full moment generating function for arbitrary
(finite) matrix size in the large signal to noise limit. Finally, we obtain the
channel capacity where the channel matrix is partly known and partly unknown
and of the form $\alpha I+ \beta H$, $\alpha,\beta$ being known constants and
entries of $H$ i.i.d. Gaussian with variance $1/n$. Channels of the form
described above are of interest for wireless transmission with multiple
antennae and receivers.


title: Thomas precession angle and spinor algebra

abstract: See math-ph/0205036 for an expanded version.


title:
Pressure-volume-temperature equation of state of MgSiO3 perovskite from
  molecular dynamics and constraints on lower mantle composition

abstract:
  The composition of the lower mantle can be investigated by examining
densities and seismic velocities of compositional models as functions of depth.
In order to do this it is necessary to know the volumes and thermoelastic
properties of the compositional constituents under lower mantle conditions. We
determined the thermal equation of state (EOS) of MgSiO3 perovskite using the
nonempirical variational induced breathing (VIB) interatomic potential with
molecular dynamics simulations at pressures and temperatures of the lower
mantle. We fit our pressure-volume-temperature results to a thermal EOS of the
form P(V,T) = P0(V,T0) + Delta Pth(T), where T0 = 300 K and P0 is the
isothermal Universal EOS. The thermal pressure Delta Pth can be represented by
a linear relationship Delta Pth = a + b T. We find V0 = 165.40 A^3, KT0 = 273
GPa, K'T0 = 3.86, a = -1.99 GPa, and b = 0.00664 GPa K^-1 for pressures of
0-140 GPa and temperatures of 300-3000 K. By fixing V0 to the experimentally
determined value of 162.49 A^3 and calculating density and bulk sound velocity
profiles along a lower mantle geotherm we find that the lower mantle cannot
consist solely of (Mg,Fe)SiO3 perovskite with XMg ranging from 0.9-1.0. Using
pyrolitic compositions of 67 vol % perovskite (XMg = 0.93-0.96) and 33 vol %
magnesiowustite (XMg = 0.82-0.86), however, we obtained density and velocity
profiles that are in excellent agreement with seismological models for a
reasonable geotherm.


title:
Application of time-dependent density functional theory to
  electron-vibration coupling in benzene

abstract:
  Optical properties of symmetry-forbidden pi-pi transitions in benzene are
calculated with the time-dependent density functional theory (TDDFT), using an
adiabatic LDA functional. Quantities calculated are the envelopes of the
Franck-Condon factors of the vibrationally promoted transitions and the
associated oscillator strengths. The strengths, which span three orders of
magnitude, are reproduced to better than a factor of two by the theory.
Comparable agreement is found for the Franck-Condon widths. We conclude that
rather detailed information can be obtained with the TDDFT and it may be
worthwhile to explore other density functionals.


title: A Historical Perspective on Cancer

abstract:
  It is proposed that cancer results from the breakdown of universal control
mechanisms which developed in mutual association as part of the historical
process that brought individual cells together into multi-cellular communities.
By systematically comparing the genomes of uni-celled with multi-celled
organisms, one might be able to identify the most promising sites for
intervention aimed at restoring the damaged control mechanisms and thereby
arresting the cancer.

categories: physics.bio-ph physics.med-ph q-bio.CB q-bio.GN q-bio.MN q-bio.OT q-bio.PE q-bio.TO


title: Newton's aether model

abstract:
  Isaac Newton is usually associated with the idea of absolute space and time,
and with ballistic light-corpuscle arguments. However, Newton was also a
proponent of wave/particle duality, and published a "new" variable-density
aether model in which light and matter trajectories were either bent by
gravitational fields, or deflected by an aether density gradient. Newton's
(flawed) aether model can be considered as an early attempt at a curved-space
model of gravity.


title: Ideal Coinstraints - A Warning Note

abstract:
  A criticism against the conception adopted by some textbook's authors
concerning ideal constraints is presented. The criticism is strengthen with two
traditional examples.


title: Elastic and Inelastic Evanescent-Wave Mirrors for Cold Atoms

abstract:
  We report on experiments on an evanescent-wave mirror for cold $^{87}$Rb
atoms. Measurements of the bouncing fraction show the importance of the Van der
Waals attraction to the surface. We have directly observed radiation pressure
parallel to the surface, exerted on the atoms by the evanescent-wave mirror. We
analyze the radiation pressure by imaging the motion of the atom cloud after
the bounce. The number of photon recoils ranges from 2 to 31. This is
independent of laser power, inversely proportional to the detuning and
proportional to the evanescent-wave decay length. By operating the mirror on an
open transition, we have also observed atoms that bounce inelastically due to a
spontaneous Raman transition. The observed distributions consist of a dense
peak at the minimum velocity and a long tail of faster atoms, showing that the
transition is a stochastic process with a strong preference to occur near the
turning point of the bounce.


title:
Spherical harmonic decomposition applied to spatial-temporal analysis of
  human high-density EEG

abstract:
  We demonstrate an application of spherical harmonic decomposition to analysis
of the human electroencephalogram (EEG). We implement two methods and discuss
issues specific to analysis of hemispherical, irregularly sampled data.
Performance of the methods and spatial sampling requirements are quantified
using simulated data. The analysis is applied to experimental EEG data,
confirming earlier reports of an approximate frequency-wavenumber relationship
in some bands.


title: A Monitor of Beam Polarization Profiles for the TRIUMF Parity Experiment

abstract:
  TRIUMF experiment E497 is a study of parity violation in pp scattering at an
energy where the leading term in the analyzing power is expected to vanish,
thus measuring a unique combination of weak-interaction flavour conserving
terms. It is desired to reach a level of sensitivity of 2x10^-8 in both
statistical and systematic errors. The leading systematic errors depend on
transverse polarization components and, at least, the first moment of
transverse polarization. A novel polarimeter that measures profiles of both
transverse components of polarization as a function of position is described.


title: Higher-order binding corrections to the Lamb shift of 2P states

abstract:
  We present an improved calculation of higher-order corrections to the
one-loop self energy of 2P states in hydrogen-like systems with small nuclear
charge Z. The method is based on a division of the integration with respect to
the photon energy into a high- and a low-energy part. The high-energy part is
calculated by an expansion of the electron propagator in powers of the Coulomb
field. The low-energy part is simplified by the application of a
Foldy-Wouthuysen transformation. This transformation leads to a clear
separation of the leading contribution from the relativistic corrections and
removes higher order terms. The method is applied to the 2P_{1/2} and 2P_{3/2}
states in atomic hydrogen. The results lead to new theoretical values for the
Lamb shifts and the fine structure splitting.


title: A phase-locked frequency divide-by-3 optical parametric oscillator

abstract:
  Accurate phase-locked 3:1 division of an optical frequency was achieved, by
using a continuous-wave (cw) doubly resonant optical parametric oscillator. A
fractional frequency stability of 2*10^(-17) of the division process has been
achieved for 100s integration time. The technique developed in this work can be
generalized to the accurate phase and frequency control of any cw optical
parametric oscillator.


title:
Diffusion Effects on the Breakdown of a Linear Amplifier Model Driven by
  the Square of a Gaussian Field

abstract:
  We investigate solutions to the equation $\partial_t{\cal E} - {\cal D}\Delta
{\cal E} = \lambda S^2{\cal E}$, where $S(x,t)$ is a Gaussian stochastic field
with covariance $C(x-x',t,t')$, and $x\in {\mathbb R}^d$. It is shown that the
coupling $\lambda_{cN}(t)$ at which the $N$-th moment $<{\cal E}^N(x,t)>$
diverges at time $t$, is always less or equal for ${\cal D}>0$ than for ${\cal
D}=0$. Equality holds under some reasonable assumptions on $C$ and, in this
case, $\lambda_{cN}(t)=N\lambda_c(t)$ where $\lambda_c(t)$ is the value of
$\lambda$ at which $<\exp\lbrack \lambda\int_0^tS^2(0,s)ds\rbrack>$ diverges.
The ${\cal D}=0$ case is solved for a class of $S$. The dependence of
$\lambda_{cN}(t)$ on $d$ is analyzed. Similar behavior is conjectured when
diffusion is replaced by diffraction, ${\cal D}\to i{\cal D}$, the case of
interest for backscattering instabilities in laser-plasma interaction.


title: Wake and Impedance

abstract:
  A systematic exposition of the basic concepts of wakes and impedances is
given for relativistic beams in accelerators.


title: Coherent control of enrichment and conversion of molecular spin isomers

abstract:
  A theoretical model of nuclear spin conversion in molecules controlled by an
external electromagnetic radiation resonant to rotational transition has been
developed. It has been shown that one can produce an enrichment of spin isomers
and influence their conversion rates in two ways, through coherences and
through level population change induced by radiation. Influence of conversion
is ranged from significant speed up to almost complete inhibition of the
process by proper choice of frequency and intensity of the external field.


title: Neutrino flux in the rotating reference frame

abstract:
  It is considered neutrino flux in the rotating reference frame. Due to the
rotation of the frame, neutrino is observed as a superposition of two states
P-transformed one from another. Since P-transformation is forbidden for
neutrino, in the rotating reference frame one can detect a half of neutrino
flux. Due to the rotation of the earth, the detector of neutrinos can measure a
half of the solar neutrino flux predicted by the SSM that may provide a
solution for the solar neutrino puzzle.