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MP: Theoretische und Mathematische Grundlagen der Physik

MP 10: Gravitation und Quantentheorie

MP 10.4: Fachvortrag

Thursday, March 20, 1997, 15:00–15:20, HS 118

The stress-energy tensor of quantum fields on Robertson-Walker and Bianchi type I space times — •Joachim Lindig — Universit"at Leipzig, Institut f. Theoretische Physik, Augustusplatz 11, 04109 Leipzig

Despite its remarkable success the standard cosmological model leaves us with open questions. A missing explanation of the observed isotropy of the cosmic expansion and the existence of particle horizons are among these unsolved problems. Vacuum quantum effects near the initial singularity offer a possibility to overcome the difficulties. A quantized, massive scalar field with nonconformal curvature coupling is considered in an isotropic Robertson-Walker as well as an anisotropic Bianchi type I background metric. The calculation of the renormalized expectation value of the stress-energy tensor is presented. The field equations are solved in some important asymptotic regions. In some cases, these solutions allow for an explicit representation of the stress-energy tensor, i.e. with explicit dependence on the background metric.