Preheating after Multifield Inflation with Nonminimal Couplings

Reheating provides a mechanism to produce particles and thermalize them to "reheat" the Universe to a sufficiently high temperature after cosmic inflation. Preheating accelerates the process of reheating by employing non-linear physics for an exponential particle production. Here we explore this phenomenon after multifield inflation in which the fields are coupled nonminimally to gravity. In the Einstein frame, this phenomenon manifests itself as a non-trivial field-space metric. Using GABE, we simulate preheating in this context and verify the consistency of our fully non-linear approach by comparing to results from perturbation theory. We extend this analysis to study when non-linearity dominates the process and preheating ceases to be efficient.