Kinetic versus thermal field theory approach to cosmological perturbations
Mar, 199441 pages
Published in:
- Phys.Rev.D 50 (1994) 2541-2559
e-Print:
- gr-qc/9403032 [gr-qc]
Report number:
- DESY-94-040,
- TUW-93-23
Citations per year
Abstract: (arXiv)
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 approach. 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.- astrophysics: perturbation
- perturbation: linear
- invariance: gauge
- particle: massless
- massless: particle
- Einstein equation
- model: gas
- model: fluid
- space-time: de Sitter
- field theory: finite temperature
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