  In cosmological evolution, it is the homogeneous scalar field (inflaton) that
drives the universe to expand isotropically and to generate standard model
particles. However, to simulate cosmology, atomic gas research has focused on
the dynamics of Bose-Einstein condensates (BEC) with continuously applied
forces. In this paper we argue a complementary approach needs also to be
pursued; we, thus, consider the analogue BEC experiments in a non-driven,
closed atomic system. We implement this using a BEC in an optical lattice
which, after a quench, freely transitions from an unstable to a stable state.
This dynamical evolution displays the counterpart "preheating", "reheating" and
"thermalization" phases of cosmology. Importantly, our studies of these
analogue processes yield tractable analytic models. Of great utility to the
cold atom community, such understanding elucidates the dynamics of
non-adiabatic condensate preparation.
