187 research outputs found
Inhomogeneity and Nonlinear Preheating
We investigated the possibility that nonlinear gravitational effects
influence the preheating era after inflation, using numerical solutions of the
inhomogeneous Einstein field equations. We compared our results to perturbative
calculations and to solutions of the nonlinear field equations in a rigid
(unperturbed) spacetime, in order to isolate gravitational phenomena. We
confirm the broad picture of preheating obtained from the nonlinear field
equations in a rigid background, but find gravitational effects have a
measurable impact on the dynamics. The longest modes in the simulation grow
much more rapidly in the relativistic calculation than with a rigid background.
We used the Weyl tensor to quantify the departure from homogeneity in the
universe. We saw no evidence for the sort of gravitational collapse that leads
to the formation of primordial black holes.Comment: Talk given at Marcel Grossmann Meeting IX. 3 pages, 1 figur
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