Nonlinear Dynamics of Preheating after Multifield Inflation with Nonminimal Couplings

Understand

We study the post-inflation dynamics of multifield models involving nonminimal couplings using lattice simulations to capture significant nonlinear effects like backreaction and rescattering.

• We measure the effective equation of state and typical time-scales for the onset of thermalization, which could affect the usual mapping between predictions for primordial perturbation spectra and measurements of anisotropies in the cosmic microwave background radiation.
• For large values of the nonminimal coupling constants, we find efficient particle production that gives rise to nearly instantaneous preheating.
• Moreover, the strong single-field attractor behavior that was previously identified persists until the end of preheating, thereby suppressing typical signatures of multifield models.