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Richard Easther Brown University During the preheating phase at the end of inflation, particles are produced by parametric resonance. An unavoidable corollary of resonance is the (selective) amplification of primordial density fluctuations, at least on length scales similar to the Hubble radius at the end of inflation. Moreover, when resonance enhances density perturbations the corresponding metric inhomogeneities must also grow. In practice, the metric fluctuations become sufficiently large for non-linear gravitational effects to become significant. Thus, in order to obtain a complete description of the preheating epoch, we have numerically solved the (inhomogenous) Einstein field equations, coupled to the non-linear field dynamics, This allows us to analyse the preheating epoch without recourse to any perturbative approximations. In this seminar I will describe the results of these simulations, and discuss the effects of the gravitational back-reaction on the dynamics of the preheating phase.
Friday, April 9th 1999, 14:00 |