Analog reheating of the early universe in the laboratory

Cosmic reheating describes the transition of the post-inflationary universe to a hot and thermal state. To shed light on the nature of this process, we propose a quantum simulation of cosmic reheating in an ultracold Bose gas. In our setup, we leverage modern experimental capabilities of modulating atomic interactions in order to account for the expansion of the universe as well as to induce parametric instabilities, mimicking the explosive particle production in the early universe. Non-linear interactions drive the system into a far-from-equilibrium state, characterized by a turbulent transport of energy towards higher moments. As we illustrate by means of classical-statistical simulations, our work opens new perspectives for an experimental study of self-similar dynamics in both universal and prescaling regimes. The proposed experiment has the potential of going beyond the weak-coupling regime of quantum field theory and access the elusive quantum-dominated relaxation to thermal equilibrium at late times.