Back Reaction of Gravitational Perturbations
arXiv:gr-qc/9702004
Abstract
The back reaction of gravitational perturbations in a homogeneous background is determined by an effective energy-momentum tensor quadratic in the perturbations. We show that this nonlinear feedback effect is important in the case of long wavelength scalar perturbations in inflationary universe models. We also show how to solve an old problem concerning the gauge dependence of the effective energy-momentum tensor of perturbations.
3 pages, LaTex using sprocl.sty, to appear in: Proceedings of the 18th Texas Symposium on Relativistic Astrophysics (eds Olinto, Frieman and Schramm, World Scientific)