The Quantum Gravitational Back-Reaction On Inflation

Abstract

We describe our recent calculation of two-loop corrections to the expansion rate of an initially inflating universe on the manifold $T^3\times \Re$. If correct, our result proves that quantum gravitational effects slow the rate of inflation by an amount which becomes non-perturbatively large at late times. In a preliminary discussion of basic issues we show that the expansion rate is a gauge invariant, and that our ultraviolet regulator does not introduce spurious time dependence. We also derive a sharp bound on the maximum strength of higher loop effects.

Comments: 65 pages, plain TeX, 5 Postscript files, uses psfig.sty, revised June 1996 for publication in Annals of Physics, note that there may be a problem rotating figures 4-9 by -90 degrees on some machines