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The semiclassical approximation to quantum gravity

C. Kiefer
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Abstract

A detailed review is given of the semiclassical approximation to quantum gravity in the canonical framework. This includes in particular the derivation of the functional Schrödinger equation and a discussion of semiclassical time as well as the derivation of quantum gravitational correction terms to the Schrödinger equation. These terms are used to calculate energy shifts for fields in De~Sitter space and non-unitary contributions in black hole evaporation. Emphasis is also put on the relevance of decoherence and correlations in semiclassical gravity. The back reaction of non-gravitational quantum fields onto the semiclassical background and the emergence of a Berry connection on superspace is also discussed in this framework.

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C. Kiefer. 1993-12-09. The semiclassical approximation to quantum gravity. https://doi.org/10.1007/3-540-58339-4_19

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