25,750 research outputs found
Bosonic Super Liouville System: Lax Pair and Solution
We study the bosonic super Liouville system which is a statistical
transmutation of super Liouville system. Lax pair for the bosonic super
Liouville system is constructed using prolongation method, ensuring the Lax
integrability, and the solution to the equations of motion is also considered
via Leznov-Saveliev analysis.Comment: LaTeX, no figures, 11 page
Reverse and Forward Slow Shocks in the Solar Wind
Reverse and forward slow shocks in solar wind from Pioneer 6 space prob
Non-Gaussian Covariance of CMB B-modes of Polarization and Parameter Degradation
The B-mode polarization lensing signal is a useful probe of the neutrino mass
and to a lesser extent the dark energy equation of state as the signal depends
on the integrated mass power spectrum between us and the last scattering
surface. This lensing B-mode signal, however, is non-Gaussian and the resulting
non-Gaussian covariance to the power spectrum cannot be ignored as correlations
between B-mode bins are at a level of 0.1. For temperature and E-mode
polarization power spectra, the non-Gasussian covariance is not significant,
where we find correlations at the 10^{-5} level even for adjacent bins. The
resulting degradation on neutrino mass and dark energy equation of state is
about a factor of 2 to 3 when compared to the case where statistics are simply
considered to be Gaussian. We also discuss parameter uncertainties achievable
in upcoming experiments and show that at a given angular resolution for
polarization observations, increasing the sensitivity beyond a certain noise
value does not lead to an improved measurement of the neutrino mass and dark
energy equation of state with B-mode power spectrum. For Planck, the resulting
constraints on the sum of the neutrino masses is ~ 0.2 eV and on the dark
energy equation of state parameter we find, sigma_w ~ 0.5.Comment: 11 pages, 5 figures, minor changes, submitted to PR
On the Classical Algebra
We consider the classical \w42 algebra from the integrable system viewpoint.
The integrable evolution equations associated with the \w42 algebra are
constructed and the Miura maps , consequently modifications, are presented.
Modifying the Miura maps, we give a free field realization the classical \w42
algebra. We also construct the Toda type integrable systems for it.Comment: 14 pages, latex, no figure
A solvable model of the evolutionary loop
A model for the evolution of a finite population in a rugged fitness
landscape is introduced and solved. The population is trapped in an
evolutionary loop, alternating periods of stasis to periods in which it
performs adaptive walks. The dependence of the average rarity of the population
(a quantity related to the fitness of the most adapted individual) and of the
duration of stases on population size and mutation rate is calculated.Comment: 6 pages, EuroLaTeX, 1 figur
Electromagnetic energy and energy flows in photonic crystals made of arrays of parallel dielectric cylinders
We consider the electromagnetic propagation in two-dimensional photonic
crystals, formed by parallel dielectric cylinders embedded a uniform medium.
The frequency band structure is computed using the standard plane-wave
expansion method, and the corresponding eigne-modes are obtained subsequently.
The optical flows of the eigen-modes are calculated by a direct computation
approach, and several averaging schemes of the energy current are discussed.
The results are compared to those obtained by the usual approach that employs
the group velocity calculation. We consider both the case in which the
frequency lies within passing band and the situation in which the frequency is
in the range of a partial bandgap. The agreements and discrepancies between
various averaging schemes and the group velocity approach are discussed in
detail. The results indicate the group velocity can be obtained by appropriate
averaging method.Comment: 23 pages, 5 figure
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