title:
Computer simulation of coherent interaction of charged particles and
  photons with crystalline solids at high energies

abstract:
  Monte Carlo simulation code has been developed and tested for studying the
passage of charged particle beams and radiation through the crystalline matter
at energies from tens of MeV up to hundreds of GeV. The developed Monte Carlo
code simulates electron, positron and photon shower in single crystals and
amorphous media. The Monte Carlo code tracks all the generations of charged
particles and photons through the aligned crystal by taking into account the
parameters of incoming beam, multiple scattering, energy loss, emission angles,
transverse dimension of beams, and linear polarization of produced photons.
  The simulation results are compared with the CERN-NA-59 experimental data.
The realistic descriptions of the electron and photon beams and the physical
processes within the silicon and germanium single crystals have been
implemented.


title: On the volatility of volatility

abstract:
  The Chicago Board Options Exchange (CBOE) Volatility Index, VIX, is
calculated based on prices of out-of-the-money put and call options on the S&P
500 index (SPX). Sometimes called the "investor fear gauge," the VIX is a
measure of the implied volatility of the SPX, and is observed to be correlated
with the 30-day realized volatility of the SPX. Changes in the VIX are observed
to be negatively correlated with changes in the SPX. However, no significant
correlation between changes in the VIX and changes in the 30-day realized
volatility of the SPX are observed. We investigate whether this indicates a
mispricing of options following large VIX moves, and examine the relation to
excess returns from variance swaps.


title:
Differential cross sections for muonic atom scattering from hydrogenic
  molecules

abstract:
  The differential cross sections for low-energy muonic hydrogen atom
scattering from hydrogenic molecules are directly expressed by the
corresponding amplitudes for muonic atom scattering from hydrogen-isotope
nuclei. The energy and angular dependence of these three-body amplitudes is
thus taken naturally into account in scattering from molecules, without
involving any pseudopotentials. Effects of the internal motion of nuclei inside
the target molecules are included for every initial rotational-vibrational
state. These effects are very significant as the considered three-body
amplitudes often vary strongly within the energy interval $\lesssim{}0.1$ eV.
The differential cross sections, calculated using the presented method, have
been successfully used for planning and interpreting many experiments in
low-energy muon physics. Studies of $\mu^{-}$ nuclear capture in $p\mu$ and the
measurement of the Lamb shift in $p\mu$ atoms created in H$_2$ gaseous targets
are recent examples.


title:
Exploring Student Understanding of Energy through the Quantum Mechanics
  Conceptual Survey

abstract:
  We present a study of student understanding of energy in quantum mechanical
tunneling and barrier penetration. This paper will focus on student responses
to two questions that were part of a test given in class to two modern physics
classes and in individual interviews with 17 students. The test, which we refer
to as the Quantum Mechanics Conceptual Survey (QMCS), is being developed to
measure student understanding of basic concepts in quantum mechanics. In this
paper we explore and clarify the previously reported misconception that
reflection from a barrier is due to particles having a range of energies rather
than wave properties. We also confirm previous studies reporting the student
misconception that energy is lost in tunneling, and report a misconception not
previously reported, that potential energy diagrams shown in tunneling problems
do not represent the potential energy of the particle itself. The present work
is part of a much larger study of student understanding of quantum mechanics.


title:
Closed form representation for a projection onto infinitely dimensional
  subspace spanned by Coulomb bound states

abstract:
  The closed form integral representation for the projection onto the subspace
spanned by bound states of the two-body Coulomb Hamiltonian is obtained. The
projection operator onto the $n^2$ dimensional subspace corresponding to the
$n$-th eigenvalue in the Coulomb discrete spectrum is also represented as the
combination of Laguerre polynomials of $n$-th and $(n-1)$-th order. The latter
allows us to derive an analog of the Christoffel-Darboux summation formula for
the Laguerre polynomials. The representations obtained are believed to be
helpful in solving the breakup problem in a system of three charged particles
where the correct treatment of infinitely many bound states in two body
subsystems is one of the most difficult technical problems.


title: Some rules of good scientific writing

abstract:
  A non-native English speaking physics professor formulates obvious yet useful
rules for writing research papers.


title: Partial Resonances of Three-Phase Composites at Long Wavelengths

abstract:
  We investigate the behaviour of a three-phase composite, structured as a
hexagonal array of coated cylinders, when the sum of the dielectric constants
of the core and shell equals zero. In such cases, the absorption of the
composite is the same as the absorption of a periodic array of solid cylinders
of core material and radius equal to the outer radius of the original coated
cylinder. When the sum of the dielectric constants of the shell and matrix
equals zero, the composite has the same absorption as a periodic array of solid
cylinders of core material, and radius exceeding the shell radius.


title: Semiconductor High-Energy Radiation Scintillation Detector

abstract:
  We propose a new scintillation-type detector in which high-energy radiation
produces electron-hole pairs in a direct-gap semiconductor material that
subsequently recombine producing infrared light to be registered by a
photo-detector. The key issue is how to make the semiconductor essentially
transparent to its own infrared light, so that photons generated deep inside
the semiconductor could reach its surface without tangible attenuation. We
discuss two ways to accomplish this, one based on doping the semiconductor with
shallow impurities of one polarity type, preferably donors, the other by
heterostructure bandgap engineering. The proposed semiconductor scintillator
combines the best properties of currently existing radiation detectors and can
be used for both simple radiation monitoring, like a Geiger counter, and for
high-resolution spectrography of the high-energy radiation. The most important
advantage of the proposed detector is its fast response time, about 1 ns,
essentially limited only by the recombination time of minority carriers.
Notably, the fast response comes without any degradation in brightness. When
the scintillator is implemented in a qualified semiconductor material (such as
InP or GaAs), the photo-detector and associated circuits can be epitaxially
integrated on the scintillator slab and the structure can be stacked-up to
achieve virtually any desired absorption capability.


title: Signal discovery in sparse spectra: a Bayesian analysis

abstract:
  A Bayesian analysis of the probability of a signal in the presence of
background is developed, and criteria are proposed for claiming evidence for,
or the discovery of a signal. The method is general and in particular
applicable to sparsely populated spectra. Monte Carlo techniques to evaluate
the sensitivity of an experiment are described. As an example, the method is
used to calculate the sensitivity of the GERDA experiment to neutrinoless
double beta decay.


title:
The Tausk Controversy in the Foundations of Quantum Mechanics: Politics,
  Mentorship and a Dissenter's Disappearance

abstract:
  In 1966, the Brazilian physicist Klaus Tausk circulated a preprint from the
International Centre for Theoretical Physics, in Trieste, criticizing the
theory put forward by Daneri, Loinger & Prosperi on the measurement problem in
quantum mechanics. This led to a heated controversy, which reflected two
opposing camps within the orthodox interpretation of quantum theory,
represented by Leon Rosenfeld and Eugene Wigner. But the controversy also went
beyond the strictly scientific issues, involving the political context of the
Cold War, the relations between developed and "Third world" countries, the use
of social skills, and personal idiosyncrasies.


title:
The Effects of Preheating of a Fine Tungsten Wire and the Polarity of a
  High-Voltage Electrode on the Energy Characteristics of an Electrically
  Exploded Wire in Vacuum

abstract:
  Results obtained from experimental and numerical studies of tungsten wires
electrical explosion in vacuum are presented. The experiments were performed
both with and without preheating of the wires, using positive or negative
polarity of a high-voltage electrode. Preheating is shown to increase energy
deposition in the wire core due to a longer resistive heating stage. The effect
was observed both in single wire and wire array experiments. The evolution of
the phase state of the wire material during explosion was examined by means of
one-dimensional numerical simulation using a semiempirical wide-range equation
of state describing the properties of tungsten with allowance made for melting
and vaporization.


title:
Role of the dihedral angle potential in the nucleation pathway of
  protein folding

abstract:
  A kinetic model for the nucleation mechanism of protein folding is proposed.
A protein is modeled as a heteropolymer consisting of hydrophobic and
hydrophilic beads with equal constant bond lengths and bond angles. The total
energy of the heteropolymer is determined by the repulsive/attractive
interactions of non-linked beads and the contribution from the dihedral angles
involved. Their parameters can be rigorously defined, unlike the ill defined
surface tension of a cluster of protein residues which is the basis of the
previous model. As a crucial idea of the model, the dihedral potential in which
a selected bead is involved is averaged over all possible configurations of
neighboring beads along the protein chain. The resulting average dihedral
potential of the residue is constant far enough from the cluster, but increases
monotonically with decreasing distance below a threshold value. An overall
potential around the cluster wherein a residue performs a chaotic motion is a
combination of the average dihedral and pairwise potentials. As a function of
distance from the cluster it has a double well shape. Residues in the inner
well are considered as belonging to the cluster (folded part of the protein)
while those in the outer well are treated as belonging to the unfolded
(although compact) part of the protein. A double well shape of the potential
around the cluster allows one to determine its emission and absorption rates by
using a first passage time analysis and develop a self-consistent kinetic
theory for the nucleation mechanism of protein folding. Numerical calculations
for a protein of 2500 residues with the diffusion coefficient of residues in
the native state ranging from 10^{-6} cm^2/s to 10^{-8} cm^2/s predict folding
times in the range from several seconds to several hundreds of seconds.


title: Energy-Length Rule

abstract:
  Lorentz ordering (causality) implies the following rule: for any given energy
p0 of a system there is a certain interval c0 on x0 so that their product is
the Lorentz ordering constant L It means p0c0 = L. The constant L=hc. Hence
Planck constant h in a similar way as c are both consequences of Lorentz
metric. The basic ideas are: 1. Lorentz metric implies that x0 must represent a
length like the other components of x in X 2. The dual metric space X* is well
defined since the Lorentz metric tensor is not singular. The components of the
vectors p in X*are interpreted as representing energy. The properties of the
physical systems that are direct consequences of the detailed structure of X
and X*, and so expressed through the Lorentz Limit L are presented.


title:
The Effect of the 12-micrometer Band: Comparing GOES-11 and GOES-12 Data
  Using the 3-Channel Volcanic Ash Algorithm

abstract:
  The 12-micrometer channel on GOES-11 has been replaced by the 13.3-micrometer
channel on the latest geosynchronous satellite, GOES-12. There has been concern
that this 13.3-micrometer channel will not be as accurate in detecting volcanic
ash. Volcanic ash is highlighted using a special volcanic ash algorithm, an
arithmetic combination of the brightness temperatures as measured by three
channels, yielding a unitless brightness count whose values comprise an IR
image. Degradation in cloud detection, especially low clouds, was also
expected. IR data from GOES-11 and GOES-12 for two Mexican volcanoes, Colima
and Popocatepetl, was analyzed. The data indicates that, in general, the
GOES-11 volcanic ash algorithm with the 12-micrometer band provides much better
data for various types of clouds. It emphasizes the importance of the
12-micrometer band and provides scope for future research in this area.


title: Maximizing Modularity is hard

abstract:
  Several algorithms have been proposed to compute partitions of networks into
communities that score high on a graph clustering index called modularity.
While publications on these algorithms typically contain experimental
evaluations to emphasize the plausibility of results, none of these algorithms
has been shown to actually compute optimal partitions. We here settle the
unknown complexity status of modularity maximization by showing that the
corresponding decision version is NP-complete in the strong sense. As a
consequence, any efficient, i.e. polynomial-time, algorithm is only heuristic
and yields suboptimal partitions on many instances.


title:
Cognitive ability experiment with photosensitive organic molecular thin
  films

abstract:
  We present an optical experiment which permits to evaluate the information
exchange necessary to self-induce cooperatively a well-organized pattern in a
randomly activated molecular assembly. A low-power coherent beam carrying
polarization and wavelength information is used to organize a surface relief
grating on a photochromic polymer thin film which is photo-activated by a
powerful incoherent beam. We demonstrate experimentally that less than 1% of
the molecules possessing information cooperatively transmit it to the entire
photo-activated polymer film.


title: Dynamical Eigenfunction Decomposition of Turbulent Pipe Flow

abstract:
  The results of an analysis of turbulent pipe flow based on a Karhunen-Lo`eve
decomposition are presented. The turbulent flow is generated by a direct
numerical simulation of the Navier-Stokes equations using a spectral element
algorithm at a Reynolds number Re_\tau=150. This simulation yields a set of
basis functions that captures 90% of the energy after 2,453 modes. The
eigenfunctions are categorised into two classes and six subclasses based on
their wavenumber and coherent vorticity structure. Of the total energy, 81% is
in the propagating class, characterised by constant phase speeds; the remaining
energy is found in the non propagating subclasses, the shear and roll modes.
The four subclasses of the propagating modes are the wall, lift, asymmetric,
and ring modes. The wall modes display coherent vorticity structures near the
wall, the lift modes display coherent vorticity structures that lift away from
the wall, the asymmetric modes break the symmetry about the axis, and the ring
modes display rings of coherent vorticity. Together, the propagating modes form
a wave packet, as found from a circular normal speed locus. The energy transfer
mechanism in the flow is a four step process. The process begins with energy
being transferred from mean flow to the shear modes, then to the roll modes.
Energy is then transfer ed from the roll modes to the wall modes, and then
eventually to the lift modes. The ring and asymmetric modes act as catalysts
that aid in this four step energy transfer. Physically, this mechanism shows
how the energy in the flow starts at the wall and then propagates into the
outer layer.


title:
Dynamics of propagating turbulent pipe flow structures. Part I: Effect
  of drag reduction by spanwise wall oscillation

abstract:
  The results of a comparative analysis based upon a Karhunen-Lo\`{e}ve
expansion of turbulent pipe flow and drag reduced turbulent pipe flow by
spanwise wall oscillation are presented. The turbulent flow is generated by a
direct numerical simulation at a Reynolds number $Re_\tau = 150$. The spanwise
wall oscillation is imposed as a velocity boundary condition with an amplitude
of $A^+ = 20$ and a period of $T^+ = 50$. The wall oscillation results in a 27%
mean velocity increase when the flow is driven by a constant pressure gradient.
The peaks of the Reynolds stress and root-mean-squared velocities shift away
from the wall and the Karhunen-Lo\`{e}ve dimension of the turbulent attractor
is reduced from 2453 to 102. The coherent vorticity structures are pushed away
from the wall into higher speed flow, causing an increase of their advection
speed of 34% as determined by a normal speed locus. This increase in advection
speed gives the propagating waves less time to interact with the roll modes.
This leads to less energy transfer and a shorter lifespan of the propagating
structures, and thus less Reynolds stress production which results in drag
reduction.


title:
Dynamics of propagating turbulent pipe flow structures. Part II:
  Relaminarization

abstract:
  The dynamical behavior of propagating structures, determined from a
Karhunen-Lo`eve decomposition, in turbulent pipe flow undergoing reverse
transition to laminar flow is investigated. The turbulent flow data is
generated by a direct numerical simulation started at a fully turbulent
Reynolds number of Re_\tau=150, which is slowly decreased until Re_\tau=95. At
this low Reynolds number the high frequency modes decay first, leaving only the
decaying streamwise vortices. The flow undergoes a chugging phenomena, where it
begins to relaminarize and the mean velocity increases. The remaining
propagating modes then destabilize the streamwise vortices, rebuild the energy
spectra, and eventually the flow regains its turbulent state. Our results
capture three chugging cycles before the flow completely relaminarizes. The
high frequency modes present in the outer layer decay first, establishing the
importance of the outer region in the self-sustaining mechanism of wall bound
turbulence.


title: Is there a linewidth theory for semiconductor lasers?

abstract:
  Semiconductor laser generation begins at a critical injection when the gain
and loss spectra touch each other at a singular frequency. In the framework of
the standard (Schawlow-Townes-Lax-Henry) theory, the finite linewidth results
from the account of fluctuations associated with the random spontaneous
emission processes. This approach is based on the assumption that in the
mean-field approximation the singular frequency generation persists for
injection levels higher than critical. We show that this assumption in the
framework of the Boltzmann kinetic equation for electrons and photons is
invalid and therefore the standard description of semiconductor laser linewidth
lacks theoretical foundation. Experimental support of the standard theory is
also questionable.


title: Variation of fundamental constants

abstract:
  We present a review of recent works devoted to the variation of the fine
structure constant alpha, strong interaction and fundamental masses. There are
some hints for the variation in quasar absorption spectra, Big Bang
nucleosynthesis, and Oklo natural nuclear reactor data. A very promising method
to search for the variation of the fundamental constants consists in comparison
of different atomic clocks. Huge enhancement of the variation effects happens
in transition between accidentally degenerate atomic and molecular energy
levels. A new idea is to build a ``nuclear'' clock based on the ultraviolet
transition between very low excited state and ground state in Thorium nucleus.
This may allow to improve sensitivity to the variation up to 10 orders of
magnitude!
  Huge enhancement of the variation effects is also possible in cold atomic and
molecular collisions near Feschbach resonance.


title: The Final Three Meters in the ILC - Can the Beam Approach 5 nm?

abstract:
  This paper has been withdrawn by the author due to a crucial error in the
force equation.


title:
Current driven rotating kink mode in a plasma column with a
  non-line-tied free end

abstract:
  First experimental measurements are presented for the kink instability in a
linear plasma column which is insulated from an axial boundary by finite sheath
resistivity. Instability threshold below the classical Kruskal-Shafranov
threshold, axially asymmetric mode structure and rotation are observed. These
are accurately reproduced by a recent kink theory, which includes axial plasma
flow and one end of the plasma column that is free to move due to a
non-line-tied boundary condition.


title: Noether's theorem in classical mechanics revisited

abstract:
  A didatic approach of the Noether's theorem in classical mechanics is derived
and used to obtain the laws of conservation.


title: Developing de Broglie Wave

abstract:
  The electromagnetic component waves, comprising together with their
generating oscillatory massless charge a material particle, will be Doppler
shifted when the charge hence particle is in motion, with a velocity $v$, as a
mere mechanical consequence of the source motion. We illustrate here that two
such component waves generated in opposite directions and propagating at speed
$c$ between walls in a one-dimensional box, superpose into a traveling beat
wave of wavelength ${\mit\Lambda}_d$$=(\frac{v}{c}){\mit\Lambda}$ and phase
velocity $c^2/v+v$ which resembles directly L. de Broglie's hypothetic phase
wave. This phase wave in terms of transporting the particle mass at the speed
$v$ and angular frequency ${\mit\Omega}_d=2\pi v /{\mit\Lambda}_d$, with
${\mit\Lambda}_d$ and ${\mit\Omega}_d$ obeying the de Broglie relations,
represents a de Broglie wave. The standing-wave function of the de Broglie
(phase) wave and its variables for particle dynamics in small geometries are
equivalent to the eigen-state solutions to Schr\"odinger equation of an
identical system.


title: Clustering Analysis of Periodic Point Vortices with the $L$ Function

abstract:
  A motion of point vortices with periodic boundary conditions is studied by
using Weierstrass zeta functions. Scattering and recoupling of a vortex pair by
a third vortex becomes remarkable when the vortex density is large. Clustering
of vortices with various initial conditions is quantitated by the $L$ function
used in point process theory in spatial ecology. It is shown that clustering
persists if it is initially clustered like an infinite row or a checkered
pattern.


title:
A novel dual-band balun based on the dual structure of composite
  right/left handed transmission line

abstract:
  Utilizing the opposite phase shifting property of a standard Composite
Right/Left Handed (CRLH) transmission line (TL) and a dual structure of CRLH
(D-CRLH) TL, a dual-band balun is designed. The dual-band balun is formed by a
1x2 (3-dB) splitter with a D-CRLH phase-shifting line in the top branch and a
CRLH phase-shifting line in the bottom branch. The performance of the balun is
verified with circuit simulation at 2.4 GHz and 5.0GHz. The balun exhibits a
very wide bandwidth for differential output phase, the return loss is well
below -100dB, and the insertion losses |S12| and |S13| are around -3.03dB at
both frequencies.


title: Problem Solving and the Use of Math in Physics Courses

abstract:
  Mathematics is an essential element of physics problem solving, but experts
often fail to appreciate exactly how they use it. Math may be the language of
science, but math-in-physics is a distinct dialect of that language. Physicists
tend to blend conceptual physics with mathematical symbolism in a way that
profoundly affects the way equations are used and interpreted. Research with
university physics students in classes from algebra-based introductory physics
indicates that the gap between what students think they are supposed to be
doing and what their instructors expect them to do can cause severe problems.


title:
On the exact number of possibilities for cutting and reconnecting the
  tour of a traveling salesman with Lin-$k$-Opts

abstract:
  When trying to find approximate solutions for the Traveling Salesman Problem
with heuristic optimization algorithms, small moves called Lin-$k$-Opts are
often used. In our paper, we provide exact formulas for the numbers of possible
tours into which a randomly chosen tour can be changed with a Lin-$k$-Opt.


title: Demonstration of an erbium doped microdisk laser on a silicon chip

abstract:
  An erbium doped micro-laser is demonstrated utilizing $\mathrm{SiO_{2}}$
microdisk resonators on a silicon chip. Passive microdisk resonators exhibit
whispering gallery type (WGM) modes with intrinsic optical quality factors of
up to $6\times{10^{7}}$ and were doped with trivalent erbium ions (peak
concentration $\mathrm{\sim3.8\times{10^{20}cm^{-3})}}$ using MeV ion
implantation. Coupling to the fundamental WGM of the microdisk resonator was
achieved by using a tapered optical fiber. Upon pumping of the $^{4}%
I_{15/2}\longrightarrow$ $^{4}I_{13/2}$ erbium transition at 1450 nm, a gradual
transition from spontaneous to stimulated emission was observed in the 1550 nm
band. Analysis of the pump-output power relation yielded a pump threshold of 43
$\mathrm{\mu}$W and allowed measuring the spontaneous emission coupling factor:
$\beta\approx1\times10^{-3}$.


title: Mechanical vs. informational components of price impact

abstract:
  We study the problem of what causes prices to change. We define the
mechanical impact of a trading order as the change in future prices in the
absence of any future changes in decision making, and its it informational
impact as the remainder of the total impact once mechanical impact is removed.
We introduce a method of measuring mechanical impact and apply it to order book
data from the London Stock Exchange. The average mechanical impact of a market
order decays to zero as a function of time, at an asymptotic rate that is
consistent with a power law with an exponent of roughly 1.7. In contrast the
average informational impact builds to approach a constant value. Initially the
impact is entirely mechanical, and is about half as big as the asymptotic
informational impact. The size of the informational impact is positively
correlated to mechanical impact. For cases where the mechanical impact is zero
for all times, we find that the informational impact is negative, i.e. buy
market orders that have no mechanical impact at all generate strong negative
price responses.


title:
On the notion of laminar and weakly turbulent elementary fluid flows: a
  simple mathematical model

abstract:
  An elementary analytical fluid flow is composed by a geometric domain, a list
of analytical constraints and by the function which depends on the physical
properties, as Reynolds number, of the considered fluid. For this object,
notions of laminar or weakly turbulent behavior are described using a simple
mathematical model.

categories: physics.flu-dyn math-ph math.MP nlin.CD nlin.CG


title: Waiting times between orders and trades in double-auction markets

abstract:
  In this paper, the survival function of waiting times between orders and the
corresponding trades in a double-auction market is studied both by means of
experiments and of empirical data. It turns out that, already at the level of
order durations, the survival function cannot be represented by a single
exponential, thus ruling out the hypothesis of constant activity during
trading. This fact has direct consequences for market microstructural models.
They must include such a non-exponential behaviour to be realistic.


title:
Pseudospectral Algorithms for Solving Nonlinear Schroedinger Equation in
  3D

abstract:
  Three pseudospectral algorithms are described (Euler, leapfrog and trapez)
for solving numerically the time dependent nonlinear Schroedinger equation in
one, two or three dimensions. Numerical stability regions in the parameter
space are determined for the cubic nonlinearity, which can be easily extended
to other nonlinearities. For the first two algorithms, maximal timesteps for
stability are calculated in terms of the maximal Fourier harmonics admitted by
the spectral method used to calculate space derivatives. The formulas are
directly applicable if the discrete Fourier transform is used, i.e. for
periodic boundary conditions. These formulas were used in the relevant
numerical programs developed in our group.


title: Liberties in Nature. On Photons, Bugs and Chess Players

abstract:
  Free will is an old philosophical enigma that has been recently revived by
neuropsychology. We restrict ourselves to the problem that determinism seems to
allow only an illusion of freedom but random decissions do not contain any
freedom either. We show that this is a problem of natural sciences, not
philosophy. Physics motivates replacing determinism by the principle of weak
causality and introducing the concept of liberty. Its empirical basis remains
untouched, but the theoretical interpretations of the state space in Newton
theory and of the space-time in general relativity are changed. The emerging
understanding of time agrees with the idea suggested once by Popper. In
biology, the most important liberties are those of mutation, of motion and of
the portable neural representation. We distinguish freedom and liberty. Each
freedom is associated with some liberty and is defined as the ability to
perform three processes called realization, selection and use of memory. This
makes freedom accessible to experimental study. The freedom of will is
explained by giving account of the underlying specific liberty and processes.
While the realization has an ample space for randomness, the selection is
mostly causal. Thus, determinism can be rejected without forcing decissions to
be random. The experiments of Libet and the role of consciousness are
discussed.


title:
To the question of identification of linear spectrum of gravitational
  emission as of an emission of the same level with electromagnetic

abstract:
  The article overviews the algorithm of identification of spectrum lines of
gravitational emission of electron with expected emission intensity close to
electromagnetic emission.


title: Energy spectrum of the Dirac oscillator in the Coulomb field

abstract:
  The spectrum of the Dirac oscillator perturbed by the Coulomb potential is
considered. The Regge trajectories for its bound states are obtained with the
method of $\hbar$-expansion. It is shown that the split of the degenerate
energy levels of the Dirac oscillator in the Coulomb field is approximately
linear in the coupling constant.


title: Growth Laws in Cancer: Implications for Radiotherapy

abstract:
  Comparing both, the more conventional Gompertz tumor growth law (GL) and the
``Universal'' law (UL), recently proposed and applied to cancer,we have
investigated the growth law's implications on various radiotherapy regimen.
  According to GL, the surviving tumor cell fraction could be reduced 'ad
libidum', independently of the initial tumor mass,simply by increasing the
number of treatments. On the contrary, if tumor growth dynamics would indeed
follow the Universal scaling law, there is a lower limit of the survival
fraction that cannot be reduced any further regardless of the total number of
treatments.
  This finding can explain the so called ``tumor size effect'' and
re-emphasizes the importance of early diagnosis as it implies that radiotherapy
may be successful provided the tumor mass at treatment onset is rather small.
  Taken together with our previous works, implications of these findings
include revisiting standard radiotherapy regimen and overall treatment
protocols.


title: The Tenth Article of Ettore Majorana

abstract:
  This year is the centenary of the birth of Ettore Majorana, one of the major
Italian physicists of all times. In this note we briefly sketch a few
biographical details about Ettore Majorana and introduce and discuss the main
points of Majorana's 10th article. In his article Majorana explicitly considers
quantum mechanics as an irreducible statistical theory because the theory is
not able to describe the time evolution of a single particle or atom in a
precise environment at a deterministic level. This lack of determinism at the
level of an elementary physical system motivated him to suggest a formal
analogy between statistical laws observed in physics and in the social
sciences. We hope the occasion of the centenary of the birth of Ettore Majorana
will be useful to remember and to reconsider not only his exceptional
achievements in theoretical physics but also his fresh and original views on
the role of statistical laws in physics and in other disciplines such as the
social sciences.


title:
Convective Patterns in Binary Fluid Mixtures with Positive Separation
  Ratios

abstract:
  We summarize our findings about laterally periodic convection structures in
binary mixtures in the Rayleigh-Benard system for positive Soret effect.
Stationary roll, square, and crossroll solutions and their stability are
determined with a multimode Galerkin expansion. The oscillatory competition of
squares and rolls in the form of crossroll oscillations is reviewed. They
undergo a subharmonic bifurcation cascade where the oscillation period grows in
integer steps as a consequence of an entrainment process.


title: Coupled continuous time random walks in finance

abstract:
  Continuous time random walks (CTRWs) are used in physics to model anomalous
diffusion, by incorporating a random waiting time between particle jumps. In
finance, the particle jumps are log-returns and the waiting times measure delay
between transactions. These two random variables (log-return and waiting time)
are typically not independent. For these coupled CTRW models, we can now
compute the limiting stochastic process (just like Brownian motion is the limit
of a simple random walk), even in the case of heavy tailed (power-law) price
jumps and/or waiting times. The probability density functions for this limit
process solve fractional partial differential equations. In some cases, these
equations can be explicitly solved to yield descriptions of long-term price
changes, based on a high-resolution model of individual trades that includes
the statistical dependence between waiting times and the subsequent
log-returns. In the heavy tailed case, this involves operator stable space-time
random vectors that generalize the familiar stable models. In this paper, we
will review the fundamental theory and present two applications with
tick-by-tick stock and futures data.


title:
Power-law distribution of individual Hirsch indices, the comparison of
  merits in different fields, and the relation to a Pareto distribution

abstract:
  A data set of Hirsch indices, $h$, for Finnish scientists in certain fields
is statistically analyzed and fitted to $h(n) =Pn^p$ for the $n$-th most-quoted
scientist. The precoefficient $P$ is characteristic for the field and the
exponent $p$ is about -0.2 for all data sets considered. For Physics, Chemistry
and Chemical Engineering, the $P$ are 49.7(8), 41.3(6), and 21.4(6),
respectively. These $p$ values correspond to Pareto exponents of about -7 for
the distribution of Hirsch indices $h$.


title: Phase Diagram of Vertically Shaken Granular Matter

abstract:
  A shallow, vertically shaken granular bed in a quasi 2-D container is studied
experimentally yielding a wider variety of phenomena than in any previous
study: (1) bouncing bed, (2) undulations, (3) granular Leidenfrost effect, (4)
convection rolls, and (5) granular gas. These phenomena and the transitions
between them are characterized by dimensionless control parameters and combined
in a full experimental phase diagram.


title: Self-Consistent Asset Pricing Models

abstract:
  We discuss the foundations of factor or regression models in the light of the
self-consistency condition that the market portfolio (and more generally the
risk factors) is (are) constituted of the assets whose returns it is (they are)
supposed to explain. As already reported in several articles, self-consistency
implies correlations between the return disturbances. As a consequence, the
alpha's and beta's of the factor model are unobservable. Self-consistency leads
to renormalized beta's with zero effective alpha's, which are observable with
standard OLS regressions. Analytical derivations and numerical simulations show
that, for arbitrary choices of the proxy which are different from the true
market portfolio, a modified linear regression holds with a non-zero value
$\alpha_i$ at the origin between an asset $i$'s return and the proxy's return.
Self-consistency also introduces ``orthogonality'' and ``normality'' conditions
linking the beta's, alpha's (as well as the residuals) and the weights of the
proxy portfolio. Two diagnostics based on these orthogonality and normality
conditions are implemented on a basket of 323 assets which have been components
of the S&P500 in the period from Jan. 1990 to Feb. 2005. These two diagnostics
show interesting departures from dynamical self-consistency starting about 2
years before the end of the Internet bubble. Finally, the factor decomposition
with the self-consistency condition derives a risk-factor decomposition in the
multi-factor case which is identical to the principal components analysis
(PCA), thus providing a direct link between model-driven and data-driven
constructions of risk factors.


title:
A new empirical approach in the Search for Extraterrestrial
  Intelligence: Astrobiological nonlocality at the cosmological level

abstract:
  Over a period of several decades a concerted effort has been made to
determine whether intelligent life exists outside of our solar system, known as
the Search for Extraterrestrial Intelligence or SETI. This has been based
primarily upon attempting to intercept possible radio transmissions at
different frequencies with arrays of radio telescopes. In addition,
astrophysical observations have also been undertaken to see if other worlds or
solar systems exist with similar conditions such as ours, which might be
conducive to life. And, numerous papers have been written exploring different
possibilities for the existence of life or why we have not observed it as of
yet, since none of these approaches have been successful. It may now be
possible to explore this issue from another standpoint. Recent theoretical and
experimental results in the field of biophysics appear to indicate the
possibility of quantum entanglement and nonlocality at the biological level,
between spatially separated pairs of human subjects and also between basins
containing neurons derived from human neural stem cells. If this research
continues to be upheld in a more replicable fashion, this could have very
important implications in the area of controllable superluminal communication.
Experiments are proposed in an attempt to address the issue of whether
controllable superluminal communication is possible and, if it is, to utilize
it in an attempt to determine if extraterrestrial intelligence really exists,
within the framework of astrobiological nonlocality.


title:
Positron-molecule annihilation by capture into vibrational Feshbach
  resonances of infrared-active modes

abstract:
  Enhanced positron annihilation on polyatomic molecules is a long-standing and
complex problem. We report the results of calculations of resonant positron
annihilation on methyl halides. A free parameter of our theory is the positron
binding energy. A comparison with energy-resolved annihilation rates measured
for CH$_3$F, CH$_3$Cl, CH$_3$Br [Barnes et al. Phys. Rev. A {\bf 74}, 012706
(2006)] shows good agreement and yields estimates of the binding energies.


title:
Elliptic function representation of doubly periodic two-dimensional
  Stokes flows

abstract:
  We construct doubly periodic Stokes flows in two dimensions using elliptic
functions. This method has advantages when the doubly periodic lattice of
obstacles has less than maximal symmetry. We find the mean flow through an
arbitrary lattice in response to a pressure gradient in an arbitrary direction,
and show in a typical example that the shorter of the two period lattice
vectors is an "easy direction" for the flow, an eigenvector of the conductance
tensor corresponding to maximal conductance.


title: QCD Explorer Proposal: E-Linac Versus E-Ring

abstract:
  TeV center of mass energy lepton-hadron collider is necessary both to clarify
fundamental aspects of strong interactions and for adequate interpretation of
the LHC data. Recently proposed QCD Explorer utilizes the energy advantage of
the LHC proton and ion beams, which allows the usage of relatively low energy
electron beam. Two options for the LHC based ep collider are posibble:
construction of a new electron ring in the LHC tunnel or construction of an
e-linac tangentially to the LHC. In the latter case, which seems more
acceptable for a number of reasons, two options are under consideration for
electron linac: the CLIC technology allows shorter linac length, whereas TESLA
technology gives higher luminosity.

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


title: Dual origin of E=mc2

abstract:
  The mass-energy relation E=mc2 has a dual origin, one grounded in the
postulate of the existence of an aether made of "ultramondane particules"
moving in space at the speed of light, c; the other, a consequence, first
deduced by Henri Poincare, of John Poynting's electromagnetic Theorem.


title: eRHIC - Accelerator and detector design studies

abstract:
  An electron-proton/ion collider facility (eRHIC) is under consideration at
Brookhaven National Laboratory (BNL). An overview of the accelerator and
detector design concepts will be provided.


title:
Vectorial modeling of near-field imaging with uncoated fiber probes:
  Transfer function and resolving power

abstract:
  Using exact three-dimensional vectorial simulations of radiation coupling
into uncoated dielectric fiber probes, we calculate amplitude transfer
functions for conical single-mode fiber tips at the light wavelength of 633 nm.
The coupling efficiency of glass fiber tips is determined in a wide range of
spatial frequencies of the incident radiation for opening angles varying from
30 to 120 degrees. The resolution in near-field imaging with these tips is
considered for field distributions limited in both direct and spatial-frequency
space. The characteristics of the transfer functions describing the relation
between probed optical fields and near-field images are analyzed in detail. The
importance of utilizing a perfectly sharp tip is also examined.


title:
Critical Behaviour in the Relaminarisation of Localised Turbulence in
  Pipe Flow

abstract:
  The statistics of the relaminarisation of localised turbulence in a pipe are
examined by direct numerical simulation. As in recent experimental data
(Peixinho & Mullin, Phys. Rev. Lett. 96, 094501, 2006), the half life for the
decaying turbulence is consistent with the scaling (Re_c-Re)^{-1}, indicating a
boundary crisis of the localised turbulent state familiar in low-dimensional
dynamical systems. The crisis Reynolds number, is estimated as Re_c=1870, a
value within 7% of the experimental value 1750. We argue that the
frequently-asked question of which Re and initial disturbance are needed to
trigger sustained turbulence in a pipe, is really two separate questions: the
`local phase space' question (local to the laminar state) of what threshold
disturbance at a given Re is needed to initially trigger turbulence, followed
by the `global phase space' question of whether Re exceeds Re_c at which point
the turbulent state becomes an attractor.


title:
Automatic Trading Agent. RMT based Portfolio Theory and Portfolio
  Selection

abstract:
  Portfolio theory is a very powerful tool in the modern investment theory. It
is helpful in estimating risk of an investor's portfolio, which arises from our
lack of information, uncertainty and incomplete knowledge of reality, which
forbids a perfect prediction of future price changes. Despite of many
advantages this tool is not known and is not widely used among investors on
Warsaw Stock Exchange. The main reason for abandoning this method is a high
level of complexity and immense calculations. The aim of this paper is to
introduce an automatic decision - making system, which allows a single investor
to use such complex methods of Modern Portfolio Theory (MPT). The key tool in
MPT is an analysis of an empirical covariance matrix. This matrix, obtained
from historical data is biased by such a high amount of statistical
uncertainty, that it can be seen as random. By bringing into practice the ideas
of Random Matrix Theory (RMT), the noise is removed or significantly reduced,
so the future risk and return are better estimated and controlled. This
concepts are applied to the Warsaw Stock Exchange Simulator http://gra.onet.pl.
The result of the simulation is 18 % level of gains in comparison for
respective 10 % loss of the Warsaw Stock Exchange main index WIG.


title: Promoting Instructional Change via Co-Teaching

abstract:
  Physics Education Research (PER) has made significant progress in developing
knowledge about teaching and learning as well as effective instructional
strategies based on this knowledge. Disseminating knowledge and strategies to
other faculty, however, has proven difficult. Coteaching is a promising and
cost-effective alternative to traditional professional development that may be
applicable in many situations. In this article, we discuss the theoretical
background of co-teaching and describe our initial experience with co-teaching.
A new instructor (MF) cotaught with an instructor experienced in PER-based
reforms (CH). The pair worked within the scaffolding of the course structure
typically used by the experienced instructor and met regularly to discuss
instructional decisions. An outsider (AB) conducted separate interviews with
each instructor at the beginning, middle, and end of the semester and observed
several class sessions. Classroom observations show an immediate use of
PER-based instructional practices by the new instructor. Interviews show a
significant shift in the new instructor's beliefs about teaching and intentions
towards future use of the PER-based instructional approaches.


title:
Physics Faculty and Educational Researchers: Divergent Expectations as
  Barriers to the Diffusion of Innovations

abstract:
  Physics Education Research (PER) practitioners have engaged in substantial
curriculum development and dissemination work in recent years. Yet, it appears
that this work has had minimal influence on the fundamental teaching practices
of typical physics faculty. To better understand this situation interviews were
conducted with 5 likely users of physics education research. All reported
making changes in their instructional practices and all were influenced, to
some extent, by educational research. Yet, none made full use of educational
research and most had complaints about their interactions with educational
researchers. In this paper we examine how these instructors used educational
research in making instructional decisions and identify divergent expectations
about how researchers and faculty can work together to improve student
learning. Although different instructors emphasized different aspects of this
discrepancy between expectations, we believe that they are all related to a
single underlying issue: the typical dissemination model is to disseminate
curricular innovations and have faculty adopt them with minimal changes while
faculty expect researchers to work with them to incorporate research-based
knowledge and materials into their unique instructional situations.
Implications and recommendations are discussed.


title: Assessing the Impact of Student Learning Style Preferences

abstract:
  Students express a wide range of preferences for learning environments. We
are trying to measure the manifestation of learning styles in various learning
environments. In particular, we are interested in performance in an environment
that disagrees with the expressed learning style preference, paying close
attention to social (group vs. individual) and auditory (those who prefer to
learn by listening) environments. These are particularly relevant to
activity-based curricula which typically emphasize group-work and de-emphasize
lectures. Our methods include multiple-choice assessments, individual student
interviews, and a study in which we attempt to isolate the learning
environment.


title:
A network-based prediction of retail stores commercial categories and
  optimal locations

abstract:
  I study the spatial organization of retail commercial activities. These are
organized in a network comprising "anti-links", i.e. links of negative weight.
  From pure location data, network analysis leads to a community structure that
closely follows the commercial classification of the US Department of Labor.
The interaction network allows to build a 'quality' index of optimal location
niches for stores, which has been empirically tested.


title:
Auxiliary-field quantum Monte Carlo study of first- and second-row
  post-d elements

abstract:
  A series of calculations for the first- and second-row post-d elements (Ga-Br
and In-I) are presented using the phaseless auxiliary-field quantum Monte Carlo
(AF QMC) method. This method is formulated in a Hilbert space defined by any
chosen one-particle basis, and maps the many-body problem into a linear
combination of independent-particle solutions with external auxiliary fields.
The phase/sign problem is handled approximately by the phaseless formalism
using a trial wave function, which in our calculations was chosen to be the
Hartree-Fock solution. We used the consistent correlated basis sets of Peterson
and coworkers, which employ a small core relativistic pseudopotential. The AF
QMC results are compared with experiment and with those from density-functional
(GGA and B3LYP) and coupled-cluster CCSD(T) calculations. The AF QMC total
energies agree with CCSD(T) to within a few milli-hartrees across the systems
and over several basis sets. The calculated atomic electron affinities,
ionization energies, and spectroscopic properties of dimers are, at large basis
sets, in excellent agreement with experiment.


title:
Stochastic volatility of financial markets as the fluctuating rate of
  trading: an empirical study

abstract:
  We present an empirical study of the subordination hypothesis for a
stochastic time series of a stock price. The fluctuating rate of trading is
identified with the stochastic variance of the stock price, as in the
continuous-time random walk (CTRW) framework. The probability distribution of
the stock price changes (log-returns) for a given number of trades N is found
to be approximately Gaussian. The probability distribution of N for a given
time interval Dt is non-Poissonian and has an exponential tail for large N and
a sharp cutoff for small N. Combining these two distributions produces a
nontrivial distribution of log-returns for a given time interval Dt, which has
exponential tails and a Gaussian central part, in agreement with empirical
observations.


title:
Modulated conjugation as a means for attaining a record high intrinsic
  hyperpolarizability

abstract:
  We report on a series of chromophores that have been synthesized with a
modulated conjugation path between donor and acceptor. Hyper-Rayleigh
scattering measurements of the best molecule show an enhanced intrinsic
hyperpolarizability that breaches the apparent limit of all previously studied
molecules.


title: Experimental demonstration of negative index of refraction

abstract:
  We introduce an improved and simplified structure made of periodic arrays of
pairs of H-shaped metallic wires that offer a potentially simpler approach in
building negative-index materials. Using simulations and microwave experiments,
we have investigated the negative-index n properties of these structures. We
have measured experimentally both the transmittance and the reflectance
properties and found unambiguously that a negative refractive index with
Re(n)<0 and Im(n) <Re(n). The same is true for epsilon and mu. Our results show
that H-shaped wire pairs can be used very effectively in producing materials
with negative refractive indices.


title: Energy Calibration of the JLab Bremsstrahlung Tagging System

abstract:
  In this report, we present the energy calibration of the Hall B
bremsstrahlung tagging system at the Thomas Jefferson National Accelerator
Facility. The calibration was performed using a magnetic pair spectrometer. The
tagged photon energy spectrum was measured in coincidence with $e^+e^-$ pairs
as a function of the pair spectrometer magnetic field. Taking advantage of the
internal linearity of the pair spectrometer, the energy of the tagging system
was calibrated at the level of $\pm 0.1% E_\gamma$. The absolute energy scale
was determined using the $e^+e^-$ rate measurements close to the end-point of
the photon spectrum. The energy variations across the full tagging range were
found to be $<3$ MeV.


title: Scaling behavior of an artificial traffic model on scale-free networks

abstract:
  In this article, we investigate an artificial traffic model on scale-free
networks. Instead of using the routing strategy of the shortest path, a
generalized routing algorithm is introduced to improve the transportation
throughput, which is measured by the value of the critical point disjoining the
free-flow phase and the congested phase. By using the detrended fluctuation
analysis, we found that the traffic rate fluctuation near the critical point
exhibits the $1/f$-type scaling in the power spectrum. The simulation results
agree very well with the empirical data, thus the present model may contribute
to the understanding of the underlying mechanism of network traffics.


title:
Quantum chaos? Genericity and nongenericity in the MHD spectrum of
  nonaxisymmetric toroidal plasmas

abstract:
  The eigenmode spectrum is a fundamental starting point for the analysis of
plasma stability and the onset of turbulence, but the characterization of the
spectrum even for the simplest plasma model, ideal magnetohydrodynamics (MHD),
is not fully understood. This is especially true in configurations with no
continuous geometric symmetry, such as a real tokamak when the discrete nature
of the external magnetic field coils is taken into account, or the alternative
fusion concept, the stellarator, where axisymmetry is deliberately broken to
provide a nonzero winding number (rotational transform) on each invariant torus
of the magnetic field line dynamics (assumed for present purposes to be an
integrable Hamiltonian system). Quantum (wave) chaos theory provides tools for
characterizing the spectrum statistically, from the regular spectrum of the
separable case (integrable semiclassical dynamics) to that where the
semiclassical ray dynamics is so chaotic that no simple classification of the
individual eigenvalues is possible (quantum chaos). The MHD spectrum exhibits
certain nongeneric properties, which we show, using a toy model, to be
understable from the number-theoretic properties of the asymptotic spectrum in
the limit of large toroidal and poloidal mode (quantum) numbers when only a
single radial mode number is retained. Much more realistically, using the ideal
MHD code CAS3D, we have constructed a data set of several hundred growth-rate
eigenvalues for an interchange-unstable three-dimensional stellarator
equilibrium with a rather flat, nonmonotonic rotational transform profile.
Statistical analysis of eigenvalue spacings shows evidence of generic quantum
chaos, which we attribute to the mixing effect of having a large number of
radial mode numbers.


title:
Characterization of doping levels in heteronuclear, gas-phase, van der
  Waals clusters and their energy absorption from an intense optical field

abstract:
  A simple mass spectrometric method has been developed to quantify dopant
levels in heteronuclear clusters in the gas phase. The method is demonstrated
with reference to quantification of the water content in supersonic beams of
water-doped argon clusters. Such doped clusters have assumed much importance in
the context of recently-reported doping-induced enhancement in the emission of
energetic charged particles and photons upon their interaction with intense
laser pulses. We have also measured the energy that a doped cluster absorbs
from the optical field; we find that energy absorption increases with
increasing level of doping. The oft-used linear model of energy absorption is
found to be quantitatively inadequate.


title:
Kinetically modified parametric instabilities of circularly-polarized
  Alfven waves: Ion kinetic effects

abstract:
  Parametric instabilities of parallel propagating, circularly polarized finite
amplitude Alfven waves in a uniform background plasma is studied, within a
framework of one-dimensional Vlasov description for ions and massless electron
fluid, so that kinetic perturbations in the longitudinal direction (ion Landau
damping) are included. The present formulation also includes the Hall effect.
The obtained results agree well with relevant analysis in the past, suggesting
that kinetic effects in the longitudinal direction play essential roles in the
parametric instabilities of Alfven waves when the kinetic effects react
"passively". Furthermore, existence of the kinetic parametric instabilities is
confirmed for the regime with small wave number daughter waves. Growth rates of
these instabilities are sensitive to ion temperature. The formulation and
results demonstrated here can be applied to Alfven waves observed in the solar
wind and in the earth's foreshock region.


title: Peer review and journal models

abstract:
  Tentative analysis of alternative peer review and journal models. Open Access
and Impact factor issues are not covered. The bibliography, in alphabetical
order, lists articles and web sites (with brief description).


title:
Monte Carlo simulation of virtual Compton scattering below pion
  threshold

abstract:
  This paper describes the Monte Carlo simulation developed specifically for
the VCS experiments below pion threshold that have been performed at MAMI and
JLab. This simulation generates events according to the (Bethe-Heitler + Born)
cross section behaviour and takes into account all relevant
resolution-deteriorating effects. It determines the `effective' solid angle for
the various experimental settings which are used for the precise determination
of photon electroproduction absolute cross section.


title:
Reality in quantum mechanics, Extended Everett Concept, and
  consciousness

abstract:
  Conceptual problems in quantum mechanics result from the specific quantum
concept of reality and require, for their solution, including the observer's
consciousness into quantum theory of measurements. Most naturally this is
achieved in the framework of Everett's "many-worlds interpretation" of quantum
mechanics. According to this interpretation, various classical alternatives are
perceived by consciousness separately from each other. In the Extended Everett
Concept (EEC) proposed by the present author, the separation of the
alternatives is identified with the phenomenon of consciousness. This explains
classical character of the alternatives and unusual manifestations of
consciousness arising "at the edge of consciousness" (i.e. in sleep or trance)
when its access to "other alternative classical realities" (other Everett's
worlds) becomes feasible. Because of reversibility of quantum evolution in EEC,
all time moments in the quantum world are equivalent while the impression of
flow of time appears only in consciousness. If it is assumed that consciousness
may influence onto probabilities of alternatives (which is consistent in case
of infinitely many Everett's worlds), EEC explains free will, "probabilistic
miracles" (observing low-probability events) and decreasing entropy in the
sphere of life.


title: Vortex shedding dynamics in the laminar wake of cones

abstract:
  Vortex Shedding Dynamics in the Laminar Wake of Cones Michel Provansal1 and
Peter A. Monkewitz1,2 1 IRPHE Aix-Marseille Universit\'{e}s FRANCE 2LMF, EPFL,
SWITZERLAND Experiments on two cones of different taper ratios have been
performed in the periodic Reynolds number range between 40 and 180. The
visualizations of the plan view of the wake with hydrogen bubbles allow to
determine local instantaneous frequencies, wavelengths and shedding angles from
digital movie. The shedding frequency adjusts in a stepwise manner to the
continuous variation of the cone diameter. Our results lead to revisit the
original work of Gaster.


title:
Incorporation of H_2 in vitreous silica, qualitative and quantitative
  determination from Raman and infrared spectroscopy

abstract:
  Incorporation mechanisms of H_2 in silica glass were studied with Raman and
infrared (IR) microspectroscopy. Hydrogenated samples were prepared at
temperatures between 800 deg C and 955 deg C at 2 kbar total pressure. Hydrogen
fugacities (f_{H_2}) were controlled using the double capsule technique with
the iron-w\"ustite (IW) buffer assemblage generating f_{H_2} of 1290-1370 bars
corresponding to H_2 partial pressures (P_{H_2}) of 960-975 bars. We found that
silica glass hydrogenated under such conditions contains molecular hydrogen
(H_2) in addition to SiH and SiOH groups. H_2 molecules dissolved in the
quenched glasses introduce a band at 4136 cm^{-1} in the Raman spectra which in
comparison to that of gaseous H_2 is wider and is shifted to lower frequency.
IR spectra of hydrogenated samples contain a band at 4138 cm^{-1} which we
assign to the stretching vibration of H_2 molecules located in
non-centrosymmetric sites. The Raman and IR spectra indicate that the dissolved
H_2 molecules interact with the silicate network. We suggest that the H_2 band
is the envelope of at least three components due to the occupation of at least
three different interstitial sites by H_2 molecules. Both, Raman and IR spectra
of hydrogenated glasses contain bands at ~2255 cm^{-1} which may be due to the
vibration of SiH groups.


title: Time's Arrow from the Multiverse Point of View

abstract:
  In this paper I suggest a possible explanation for the asymmetry of time. In
the case that I study, the dynamical laws and the boundary conditions are
symmetric, but the behavior of time is not. The underlying mechanism is
statistical and closely related to the idea of multiple histories in quantum
mechanics, but otherwise rather independent of the particular framework.


title: Detrending Moving Average variance: a derivation of the scaling law

abstract:
  The Hurst exponent $H$ of long range correlated series can be estimated by
means of the Detrending Moving Average (DMA) method. A computational tool
defined within the algorithm is the generalized variance $
\sigma_{DMA}^2={1}/{(N-n)}\sum_i [y(i)-\widetilde{y}_n(i)]^2\:$, with
$\widetilde{y}_n(i)= {1}/{n}\sum_{k}y(i-k)$ the moving average, $n$ the moving
average window and $N$ the dimension of the stochastic series $y(i)$. This
ability relies on the property of $\sigma_{DMA}^2$ to scale as $n^{2H}$. Here,
we analytically show that $\sigma_{DMA}^2$ is equivalent to $C_H n^{2H}$ for
$n\gg 1$ and provide an explicit expression for $C_H$.


title:
Towards measuring nuclear-spin-dependent and isotopic-chain atomic
  parity violation in Ytterbium

abstract:
  We discuss experiments aimed at measurements of atomic parity nonconservation
(PNC) effects in the 1S0-3D1 transition (408 nm) in atomic Ytterbium (Z=70).
According to theoretical predictions, the PNC-induced E1 amplitude of this
transition is ~100 times larger than the analogous amplitude in Cs. Such an
experiment will determine differences in PNC effects between different
hyperfine components for odd-neutron-number Yb isotopes and, thereby, will
allow measurements of the nuclear anapole moments in nuclei with unpaired
neutrons. In addition, measurements of PNC in different isotopes would give
information on neutron distributions within the nuclei. The apparatus designed
and built for this experiment is described, and results of measurements towards
understanding of systematic effects influencing the accuracy, and the current
status of the ongoing PNC measurements are presented.


title:
Variational method for estimating the rate of convergence of Markov
  Chain Monte Carlo algorithms

abstract:
  We demonstrate the use of a variational method to determine a quantitative
lower bound on the rate of convergence of Markov Chain Monte Carlo (MCMC)
algorithms as a function of the target density and proposal density. The bound
relies on approximating the second largest eigenvalue in the spectrum of the
MCMC operator using a variational principle and the approach is applicable to
problems with continuous state spaces. We apply the method to one dimensional
examples with Gaussian and quartic target densities, and we contrast the
performance of the Random Walk Metropolis-Hastings (RWMH) algorithm with a
``smart'' variant that incorporates gradient information into the trial moves.
We find that the variational method agrees quite closely with numerical
simulations. We also see that the smart MCMC algorithm often fails to converge
geometrically in the tails of the target density except in the simplest case we
examine, and even then care must be taken to choose the appropriate scaling of
the deterministic and random parts of the proposed moves. Again, this calls
into question the utility of smart MCMC in more complex problems. Finally, we
apply the same method to approximate the rate of convergence in
multidimensional Gaussian problems with and without importance sampling. There
we demonstrate the necessity of importance sampling for target densities which
depend on variables with a wide range of scales.


title:
Biological Principles in Self-Organization of Young Brain - Viewed from
  Kohonen Model

abstract:
  Variants of the Kohonen model are proposed to study biological principles of
self-organization in a model of young brain. We suggest a function to measure
aquired knowledge and use it to auto-adapt the topology of neuronal
connectivity, yielding substantial organizational improvement relative to the
standard model. In the early phase of organization with most intense learning,
we observe that neural connectivity is of Small World type, which is very
efficient to organize neurons in response to stimuli. In analogy to human brain
where pruning of neural connectivity (and neuron cell death) occurs in early
life, this feature is present also in our model, which is found to stabilize
neuronal response to stimuli.


title: Preparing graduate students to be educators

abstract:
  We present two programs that address needs to better prepare graduate
students for their roles as professional physicists, particularly in the areas
of teaching and education research. The two programs, Preparing Future
Physicists (PFP) and a course, Teaching and Learning Physics, are designed to
be mutually supportive, address these broader graduate roles, and support the
development of the field of physics education research. While voluntary, PFP
has attracted the participation of roughly half the physics graduate students
at each of two large research institutions. Compared to the national rate,
these students are roughly twice as likely to report an interest in pursuing
future roles as educators. While less than one in five of participants surveyed
reported education being valued by the research community in physics, more than
90% reported intentions to incorporate the results of research in physics
education in their future teaching. Experience with the synergistic program,
Teaching and Learning Physics, demonstrates that it is possible to replicate
earlier successes of the program initiated at a different institution,
including increasing student mastery of physics, developing student interest in
education and teaching, and engaging students in research projects in physics
education. In addition to introducing these programs, we identify some of the
critical features that contribute to their successes.


title:
On the simulation of enzymatic digest patterns: the fragmentation of
  oligomeric and polymeric galacturonides by endo-polygalacturonase II

abstract:
  A simulation methodology for predicting the time-course of enzymatic
digestions is described. The model is based solely on the enzyme's subsite
architecture and concomitant binding energies. This allows subsite binding
energies to be used to predict the evolution of the relative amounts of
different products during the digestion of arbitrary mixtures of oligomeric or
polymeric substrates. The methodology has been specifically demonstrated by
studying the fragmentation of a population of oligogalacturonides of varying
degrees of polymerization, when digested by endo-polygalacturonase II (endo-PG
II) from Aspergillus niger.


title: Single Member Selection in Ensemble Forecasting

abstract:
  Ensemble forecasting is a technique devised to palliate sensitivity to
initial conditions in nonlinear dynamical systems. The basic idea to avoid this
sensitivity is to run the model many times under several slightly-different
initial conditions, merging the resulting forecast in a combined product. We
argue that this blending procedure is unphysical, and that a single trajectory
should be chosen instead. We illustrate our case with a climate model. While
most of the current climate simulations use the ensemble average technique as
merging procedure, this paper shows that this choice presents several
drawbacks, including a serious underestimation of future climate extremes. It
is also shown that a sensible choice of a single estimate from the ensemble
solves this problem, partly overcoming the inherent sensitivity to initial
conditions of those non-linear systems with a large number of degrees of
freedom.


title:
Dynamics of the Warsaw Stock Exchange index as analysed by the
  nonhomogeneous fractional relaxation equation

abstract:
  We analyse the dynamics of the Warsaw Stock Exchange index WIG at a daily
time horizon before and after its well defined local maxima of the cusp-like
shape decorated with oscillations. The rising and falling paths of the index
peaks can be described by the Mittag-Leffler function superposed with various
types of oscillations. The latter is a solution of our model of index dynamics
defined by the nonhomogeneous fractional relaxation equation. This solution is
a generalised analog of an exactly solvable model of viscoelastic materials. We
found that the Warsaw Stock Exchange can be considered as an intermediate
system lying between two complex ones, defined by short and long-time limits of
the Mittag-Leffler function; these limits are given by the
Kohlraush-Williams-Watts law for the initial times, and the power-law or the
Nutting law for asymptotic time. Hence follows the corresponding short- and
long-time power-law behaviour (different universality classes) of the
time-derivative of the logarithm of WIG which can in fact be viewed as the
finger print of a dynamical critical phenomenon.


title: Modification to Special Relativity

abstract:
  The speed of light is usually taken as one of the fundamental constants.
String, and field, theories appear to require the altercation of this constant
into a functional form $E(m,c)$ which is not $E=mc^2$. The analysis requires
the re-interpretation of the renormalization group flow equations. There are
quantum corrections to the mass-energy relation generically for particles of
any sort. A breakdown of special relativity follows. Cosmological data might be
one of the best testbeds to analyze the computable functional forms of the mass
energy relations.


title:
D\'eveloppement d'instabilit\'es dans un \'ecoulement subsonique se
  d\'eveloppant au-dessus d'une cavit\'e : mesures synchronis\'ees PIV-LDV

abstract:
  A boundary layer interacting with a cavity is a benchmark case that is
present in environmental applications, aeronautics, automobile aerodynamics or
industrial applications, where the velocity over a rectangular cavity is
relatively low. In the present investigation, the interaction between a laminar
boundary layer with external velocity Ue and an open cavity is investigated
experimentally for medium range Reynolds numbers (between 4600 and 18500) with
flow diagnostics optical methods, for a cavity aspect ratio (length over depth)
of two. A shear layer induces a main vortex and a counter-rotating secondary
vortex inside the cavity. The shear layer also develops instabilities
interacting with the downstream cavity edge. Particle image velocimetry (PIV)
and laser Doppler velocimetry (LDV) measurements are synchronized in order to
get global information of both spatial velocity fields and time-resolved
signals in a particular position situated downstream of the development of the
shear layer above the cavity. The PIV velocity fields are phase-averaged with a
singular value decomposition of the LDV signal.


title: Directional emission of stadium-shaped micro-lasers

abstract:
  The far-field emission of two dimensional (2D) stadium-shaped dielectric
cavities is investigated. Micro-lasers with such shape present a highly
directional emission. We provide experimental evidence of the dependance of the
emission directionality on the shape of the stadium, in good agreement with ray
numerical simulations. We develop a simple geometrical optics model which
permits to explain analytically main observed features. Wave numerical
calculations confirm the results.


title: Nonsequential Double Recombination in Intense Laser Fields

abstract:
  A second plateau in the harmonic spectra of laser-driven two-electron atoms
is observed both in the numerical solution of a low-dimensional model helium
atom and using an extended strong field approximation. It is shown that the
harmonics well beyond the usual cut-off are due to the simultaneous
recombination of the two electrons, which were emitted during different,
previous half-cycles. The new cut-off is explained in terms of classical
trajectories. Classical predictions and the time-frequency analysis of the ab
initio quantum results are in excellent agreement. The mechanism corresponds to
the inverse single photon double ionization process in the presence of a (low
frequency) laser field.


title:
A Generalized Preferential Attachment Model for Business Firms Growth
  Rates: I. Empirical Evidence

abstract:
  We introduce a model of proportional growth to explain the distribution
$P(g)$ of business firm growth rates. The model predicts that $P(g)$ is Laplace
in the central part and depicts an asymptotic power-law behavior in the tails
with an exponent $\zeta=3$. Because of data limitations, previous studies in
this field have been focusing exclusively on the Laplace shape of the body of
the distribution. We test the model at different levels of aggregation in the
economy, from products, to firms, to countries, and we find that the its
predictions are in good agreement with empirical evidence on both growth
distributions and size-variance relationships.


title: Multiple Solutions in Fluid Mechanics

abstract:
  The principle of multiple solutions of the Navier-Stokes equations discussed
in this paper is not directed at any particular problems in fluid dynamics, nor
at any specific applications. The non-uniqueness principle states that the
Reynolds number, above its critical value, is insufficient to uniquely
determine a flow field for a given geometry, or for similar geometries. It is a
generic principle for all fluid flow and its transportation properties, but is
not well understood. It compliments the current popular bifurcation theories by
the fact that multiple solutions can exist on each stable bifurcation branch.


title: Simple Theoretical Models for Resonant Cold Atom Interactions

abstract:
  Magnetically tunable scattering resonances have been used with great success
for precise control of s-wave scattering lengths in ultracold atomic
collisions. We describe relatively simple yet quite powerful analytic
treatments of such resonances based on the analytic properties of the van der
Waals long range potential. This theory can be used to characterize a number of
properties of specific resonances that have been used successfully in various
experiments with $^{87}$Rb, $^{85}$Rb, $^{40}$K, and $^{6}$Li. Optical Feshbach
resonances are also possible and may be practical with narrow intercombination
line photoassociative transitions in species like Sr and Yb.


title:
Limit on the Temporal Variation of the Fine-Structure Constant Using
  Atomic Dysprosium

abstract:
  Over a period of eight months, we have monitored transition frequencies
between nearly degenerate, opposite-parity levels in two isotopes of atomic
dysprosium (Dy). These transition frequencies are highly sensitive to temporal
variation of the fine-structure constant ($\alpha$) due to relativistic
corrections of large and opposite sign for the opposite-parity levels. In this
unique system, in contrast to atomic-clock comparisons, the difference of the
electronic energies of the opposite-parity levels can be monitored directly
utilizing a radio-frequency (rf) electric-dipole transition between them. Our
measurements show that the frequency variation of the 3.1-MHz transition in
$^{163}$Dy and the 235-MHz transition in $^{162}$Dy are 9.0$\pm$6.7 Hz/yr and
-0.6$\pm$6.5 Hz/yr, respectively. These results provide a value for the rate of
fractional variation of $\alpha$ of $(-2.7\pm2.6)\times 10^{-15}$ yr$^{-1}$ (1
$\sigma$) without any assumptions on the constancy of other fundamental
constants, indicating absence of significant variation at the present level of
sensitivity.


title: Influence of Morphology on the Optical Properties of Metal Nanoparticles

abstract:
  The influence of morphology on the optical properties of silver nanoparticles
is studied. A general relationship between the surface plasmon resonances and
the morphology of each nanoparticle is established. The optical response is
investigated for cubes and decahedrons with different truncations. We found
that polyhedral nanoparticles composed with less faces show more surface
plasmon resonances than spherical-like ones. It is also observed that the
vertices of the nanoparticles play an important role in the optical response,
because the sharpener they become, the greater the number of resonances. For
all the nanoparticles, a main resonance with a dipolar character was identified
as well as other secondary resonances of less intensity. It is also found that
as the nanoparticle becomes more symmetric, the main resonance is always blue
shifted.


title:
Possible Orientation Effects to the Phase Diagram of Fundamental
  Composite Particles

abstract:
  We obtain possibly valuable information about the phase diagram of rather
dense composite particles at high fermion as well as boson number density but
low temperature, which is not accessible to relativistic heavy ion collision
experiments. Our calculations could qualitatively measure the number of
thermodynamic degrees of freedom at the time at which the matter (produced in
heavy ion collisions which might be a deconfined quark-gluon plasma) comes into
approximate local thermal equilibrium and begins to behave like a hydrodynamic
fluid. Possible observational signatures associated with the theoretically
proposed states of matter inside compact stars are discussed as well.


title: Scalar Top Study: Detector Optimization

abstract:
  A vertex detector concept of the Linear Collider Flavour Identification
(LCFI) collaboration, which studies pixel detectors for heavy quark flavour
identification, has been implemented in simulations for c-quark tagging in
scalar top studies. The production and decay of scalar top quarks (stops) is
particularly interesting for the development of the vertex detector as only two
c-quarks and missing energy (from undetected neutralinos) are produced for
light stops. Previous studies investigated the vertex detector design in
scenarios with large mass differences between stop and neutralino,
corresponding to large visible energy in the detector. In this study we
investigate the tagging performance dependence on the vertex detector design in
a scenario with small visible energy for the International Linear Collider
(ILC).


title: Muon ID at the ILC

abstract:
  This paper describes a new way to reconstruct and identify muons with high
efficiency and high pion rejection. Since muons at the ILC are often produced
with or in jets, for many of the physics channels of interest[1], an efficient
algorithm to deal with the identification and separation of particles within
jets is important. The algorithm at the core of the method accounts for the
effects of the magnetic field and for the loss of energy by charged particles
due to ionization in the detector. We have chosen to develop the analysis
within the setup of one of the Linear Collider Concept Detectors adopted by the
US. Within b-pair production jets, particles cover a wide range in momenta;
however ~ 80% of the particles have a momentum below 30 GeV[2]. Our study,
focused on bbar-b jets, is preceded by a careful analysis of single energy
particles between 2 and 50 GeV. As medium energy particles are a substantial
component of the jets, many of the particles lose part of their energy in the
calorimeters and the solenoid coil before reaching the muon detector where they
may have energy below 2 GeV. To deal with this problem we have implemented a
Runge-Kutta correction of the calculated trajectory to better handle these
lower energy particles. The multiple scattering and other stochastic processes,
more important at lower energy, is addressed by a Kalman-filter integrated into
the reconstruction algorithm. The algorithm provides a unique and powerful
separation of muons from pions. The 5 Tesla magnetic field from a solenoid
surrounds the hadron calorimeter and allows the reconstruction and precision
momentum measurement down to a few GeV.


title: Anomalous transparency of water-air interface for low-frequency sound

abstract:
  Sound transmission through water-air interface is normally weak because of a
strong mass density contrast. Here we show that the transparency of the
interface increases dramatically at low frequencies. Rather counterintuitively,
almost all acoustic energy emitted by a sufficiently shallow monopole source
under water is predicted to be radiated into atmosphere. Physically, increased
transparency at lower frequencies is due to the increasing role of
inhomogeneous waves and a destructive interference of direct and
surface-reflected waves under water. The phenomenon of anomalous transparency
has significant implications for acoustic communication across the water-air
interface, generation of ambient noise, and detection of underwater explosions.


title:
A Generalized Preferential Attachment Model for Business Firms Growth
  Rates: II. Mathematical Treatment

abstract:
  We present a preferential attachment growth model to obtain the distribution
$P(K)$ of number of units $K$ in the classes which may represent business firms
or other socio-economic entities. We found that $P(K)$ is described in its
central part by a power law with an exponent $\phi=2+b/(1-b)$ which depends on
the probability of entry of new classes, $b$. In a particular problem of city
population this distribution is equivalent to the well known Zipf law. In the
absence of the new classes entry, the distribution $P(K)$ is exponential. Using
analytical form of $P(K)$ and assuming proportional growth for units, we derive
$P(g)$, the distribution of business firm growth rates. The model predicts that
$P(g)$ has a Laplacian cusp in the central part and asymptotic power-law tails
with an exponent $\zeta=3$. We test the analytical expressions derived using
heuristic arguments by simulations. The model might also explain the
size-variance relationship of the firm growth rates.


title: Transport induced by Density Waves in a Andreev-Lifshitz Supersolid

abstract:
  Macroscopic derivation of the entrainment in in a Andreev-Lifshitz Supersolid
induced by a surface elastic wave propagating along the flexible interface is
conducted by considering the nonlinear coupling between the interface and the
rarefaction effect. We obtain the critical bounds for zero-volume-flow-rate
states corresponding to specific rarefaction measure and wave number which is
relevant to the rather small critical velocity of supersolid flows reported by
Kim and Chan.


title: Supersymmetric Jaynes-Cummings model and its exact solutions

abstract:
  The super-algebraic structure of a generalized version of the Jaynes-Cummings
model is investigated. We find that a Z2 graded extension of the so(2,1) Lie
algebra is the underlying symmetry of this model. It is isomorphic to the
four-dimensional super-algebra u(1/1) with two odd and two even elements.
Differential matrix operators are taken as realization of the elements of the
superalgebra to which the model Hamiltonian belongs. Several examples with
various choices of superpotentials are presented. The energy spectrum and
corresponding wavefunctions are obtained analytically.


title:
Relativistic aberration effect on the the light reflection law and the
  form of reflecting surface in a moving reference frame

abstract:
  The influence of the relativistic motion of the reference frame on the light
reflection law is investigated. The method is based on applying the
relativistic aberration affect for three light signals: incident, normal and
reflected rays. The form of the reflection law in the moving reference frame is
substantially modified and includes an additional parameter which is the
velocity vector of the reference frame.
  It is shown that the reflected ray, as measured by a moving observer, would
not in general be in the same plane as the incident and normal rays. A general
method to transform the form of any rigid surface in 3-dimensional space with
respect to the arbitrary directed relative motion of the reference frame is
detailed. This method is based on the light signals processes and the
invariance of the light velocity under Lorentz transformations. It is shown
that a moving observer will measure a plane surface as a hyperboloid. That
observer will also measure a spherical surface as an ellipsoid. A right line in
the plane is seen by a moving observer as a hyperbola. The whole analysis is
extended to the case of a uniform media.


title: Surface Waves on a Semi-toroidal Water Ring

abstract:
  We study the dynamics of surface waves on a semi-toroidal ring of water that
is excited by vertical vibration. We create this specific fluid volume by
patterning a glass plate with a hydrophobic coating, which confines the fluid
to a precise geometric region. To excite the system, the supporting plate is
vibrated up and down, thus accelerating and decelerating the fluid ring along
its toroidal axis. When the driving acceleration is sufficiently high, the
surface develops a standing wave, and at yet larger accelerations, a traveling
wave emerges. We also explore frequency dependencies and other geometric shapes
of confinement.


title:
Carbon Supported Polyaniline as Anode Catalyst: Pathway to Platinum-Free
  Fuel Cells

abstract:
  The effectiveness of carbon supported polyaniline as anode catalyst in a fuel
cell (FC) with direct formic acid electrooxidation is experimentally
demonstrated. A prototype FC with such a platinum-free composite anode
exhibited a maximum room-temperature specific power of about 5 mW/cm2


title: On the Machian Origin of Inertia

abstract:
  We examine Sciama's inertia theory: we generalise it, by combining rotation
and expansion in one unique model, we find the angular speed of the Universe,
and we stress that the theory is zero-total-energy valued. We compare with
other theories of the same null energy background. We determine the numerical
value of a constant which appears in the Machian inertial force expression
devised by Graneau and Graneau[2], by introducing the above angular speed. We
point out that this last theory is not restricted to Newtonian physics as those
authors stated but is, in fact, compatible with other cosmological and
gravitational theories. An argument by Berry[7] is shown in order to "derive"
Brans-Dicke relation in the present context.


title:
Derivation of the Maxwell's Equations Based on a Continuum Mechanical
  Model of Vacuum and a Singularity Model of Electric Charges

abstract:
  We speculate that the universe may be filled with a visco-elastic continuum
which may be called aether. Thus, the Maxwell's equations in vacuum are derived
by methods of continuum mechanics based on a continuum mechanical model of
vacuum and a singularity model of electric charges.


title: Large atom number Bose-Einstein condensate of sodium

abstract:
  We describe the setup to create a large Bose-Einstein condensate containing
more than 120x10^6 atoms. In the experiment a thermal beam is slowed by a
Zeeman slower and captured in a dark-spot magneto-optical trap (MOT). A typical
dark-spot MOT in our experiments contains 2.0x10^10 atoms with a temperature of
320 microK and a density of about 1.0x10^11 atoms/cm^3. The sample is spin
polarized in a high magnetic field, before the atoms are loaded in the magnetic
trap. Spin polarizing in a high magnetic field results in an increase in the
transfer efficiency by a factor of 2 compared to experiments without spin
polarizing. In the magnetic trap the cloud is cooled to degeneracy in 50 s by
evaporative cooling. To suppress the 3-body losses at the end of the
evaporation the magnetic trap is decompressed in the axial direction.


title: On chemisorption of polymers to solid surfaces

abstract:
  The irreversible adsorption of polymers to a two-dimensional solid surface is
studied. An operator formalism is introduced for chemisorption from a
polydisperse solution of polymers which transforms the analysis of the
adsorption process to a set of combinatorial problems on a two-dimensional
lattice. The time evolution of the number of polymers attached and the surface
area covered are calculated via a series expansion. The dependence of the final
coverage on the parameters of the model (i.e. the parameters of the
distribution of polymer lengths in the solution) is studied. Various methods
for accelerating the convergence of the resulting infinite series are
considered. To demonstrate the accuracy of the truncated series approach, the
series expansion results are compared with the results of stochastic
simulation.


title: Debye representation of dispersive focused waves

abstract:
  We report on a matrix-based diffraction integral that evaluates the focal
field of any diffraction-limited axisymmetric complex system. This diffraction
formula is a generalization of the Debye integral applied to apertured focused
beams, which may be accommodated to broadband problems. Longitudinal chromatic
aberration may limit the convenience of the Debye formulation and,
additionally, spatial boundaries of validity around the focal point are
provided. Fresnel number is reformulated in order to guarantee that the focal
region is entirely into the region of validity of the Debye approximation when
the Fresnel number of the focusing geometry largely exceeds unity. We have
applied the matrix-based Debye integral to several examples. Concretely, we
present an optical system for beam focusing with strong angular dispersion and
free of longitudinal chromatic aberration. This simple formalism leaves an open
door for analysis and design of focused beams with arbitrary angular
dispersion. Our results are valid for ultrashort pulsed and polychromatic
incoherent sources.


title: Traffic flow and efficient routing on scale-free networks: A survey

abstract:
  Recently, motivated by the pioneer works in revealing the small-world effect
and scale-free property of various real-life networks, many scientists devote
themselves to studying complex networks. In this paper, we give a brief review
on the studies of traffic flow and efficient routing on scale-free networks,
including the traffic dynamics based on global routing protocol, Traffic
dynamics based on local routing protocol, and the critical phenomena and
scaling behaviors of real and artificial traffic. Finally, perspectives and
some interesting problems are proposed.


title: Icosahedral quasicrystals by optical interference holography

abstract:
  Optical interference holography has been proved to be a useful technique in
fabricating periodic photonic crystals in which electromagnetic waves are
forbidden in certain frequency bandgaps. Compared to periodic crystals
quasicrystals, having higher point group symmetry, are more favourable in
achieving complete bandgaps. In this report, we propose two seven-beam optical
interference configurations based on the reciprocal vector space
representations for quasicrystals to fabricate icosahedral quasicrystals.
Interference simulations for the quasicrystals exhibit the full symmetry of an
icosahedron. The result paves the path for the fabrication of photonic
quasicrystals using holographic lithography.


title:
Orbital and spin components of the angular momentum of a general
  electromagnetic field

abstract:
  A decomposition of the angular momentum of the classical electromagnetic
field into orbital and spin components that is manifestly gauge invariant and
general has been obtained. This is done by decomposing the electric field into
its longitudinal and transverse parts by means of the Helmholtz theorem. The
orbital and spin components of the angular momentum of any specified
electromagnetic field can be found from this prescription.


title: Inelastic Scattering and Interactions of Three-Wave Parametric Solitons

abstract:
  We study the excitation, decay and interactions of novel, velocity locked
three-wave parametric solitons in a medium with quadratic nonlinearity and
dispersion. We analytically describe the particle-like scattering between
stable or unstable soliton triplets with linear waves in terms of explicit
solutions featuring accelerated or decelerated solitons.


title: Dwell time of a Brownian interacting molecule in a cellular microdomain

abstract:
  The time spent by an interacting Brownian molecule inside a bounded
microdomain has many applications in cellular biology, because the number of
bounds is a quantitative signal, which can initiate a cascade of chemical
reactions and thus has physiological consequences. In the present article, we
propose to estimate the mean time spent by a Brownian molecule inside a
microdomain $\Omega$ which contains small holes on the boundary and agonist
molecules located inside. We found that the mean time depends on several
parameters such as the backward binding rate (with the agonist molecules), the
mean escape time from the microdomain and the mean time a molecule reaches the
binding sites (forward binding rate). In addition, we estimate the mean and the
variance of the number of bounds made by a molecule before it exits $\Omega$.
These estimates rely on a boundary layer analysis of a conditional mean first
passage time, solution of a singular partial differential equation. In
particular, we apply the present results to obtain an estimate of the mean time
spent (Dwell time) by a Brownian receptor inside a synaptic domain, when it
moves freely by lateral diffusion on the surface of a neuron and interacts
locally with scaffolding molecules.


title:
Economic sector identification in a set of stocks traded at the New York
  Stock Exchange: a comparative analysis

abstract:
  We review some methods recently used in the literature to detect the
existence of a certain degree of common behavior of stock returns belonging to
the same economic sector. Specifically, we discuss methods based on random
matrix theory and hierarchical clustering techniques. We apply these methods to
a set of stocks traded at the New York Stock Exchange. The investigated time
series are recorded at a daily time horizon.
  All the considered methods are able to detect economic information and the
presence of clusters characterized by the economic sector of stocks. However,
different methodologies provide different information about the considered set.
Our comparative analysis suggests that the application of just a single method
could not be able to extract all the economic information present in the
correlation coefficient matrix of a set of stocks.


title: Quasiparticle properties in a density functional framework

abstract:
  We propose a framework to construct the ground-state energy and density
matrix of an N-electron system by solving selfconsistently a set of
single-particle equations. The method can be viewed as a non-trivial extension
of the Kohn-Sham scheme (which is embedded as a special case). It is based on
separating the Green's function into a quasi-particle part and a background
part, and expressing only the background part as a functional of the density
matrix. The calculated single-particle energies and wave functions have a clear
physical interpretation as quasiparticle energies and orbitals.


title:
Detecting the traders' strategies in Minority-Majority games and real
  stock-prices

abstract:
  Price dynamics is analyzed in terms of a model which includes the possibility
of effective forces due to trend followers or trend adverse strategies. The
method is tested on the data of a minority-majority model and indeed it is
capable of reconstructing the prevailing traders' strategies in a given time
interval. Then we also analyze real (NYSE) stock-prices dynamics and it is
possible to derive an indication for the the ``sentiment'' of the market for
time intervals of at least one day.