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arXiv · gr-qc/9704010

Stochastic semiclassical cosmological models

E. Calzetta·A. Campos·E. Verdaguer
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Abstract

We consider the classical stochastic fluctuations of spacetime geometry induced by quantum fluctuations of massless non-conformal matter fields in the Early Universe. To this end, we supplement the stress-energy tensor of these fields with a stochastic part, which is computed along the lines of the Feynman-Vernon and Schwinger-Keldysh techniques; the Einstein equation is therefore upgraded to a so called Einstein-Langevin equation. We consider in some detail the conformal fluctuations of flat spacetime and the fluctuations of the scale factor in a simple cosmological modelintroduced by Hartle, which consists of a spatially flat isotropic cosmology driven by radiation and dust.

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E. Calzetta, A. Campos, E. Verdaguer. 1997-04-04. Stochastic semiclassical cosmological models. https://doi.org/10.1103/physrevd.56.2163

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