Mathematica 9 is now available

Wolfram Library Archive


Courseware Demos MathSource Technical Notes
All Collections Articles Books Conference Proceedings
Title

Kinetic Versus Thermal-Field Theory Approach to Cosmological Perturbations
Authors

A. Rebhan
D. Schwartz
Journal / Anthology

Physical Review D
Year: 1994
Volume: 50
Issue: 4
Page range: 2541-2547
Description

A closed set of equations for the evolution of linear perturbations of homogeneous, isotropic cosmological models can be obtained in various ways. The simplest approach is to assume a macroscopic equation of state, e.g., that of a perfect fluid. For a more refined description of the early Universe, a microscopic treatment is required. The purpose of this paper is to compare the approach based on classical kinetic theory to the more recent thermal-field-theory aproach. It is shown that in the high-temperature limit the latter describes cosmological perturbations supported by collisionless, massless matter, wherein it is equivalent to the kinetic theory approach. The dependence of the perturbations in a system of a collisionless gas and a perfect fluid on the initial data is discussed in some detail. All singular and regular solutions are found analytically.
Subject

*Science > Physics > Astrophysics