Speaker
Description
Oscillating spacetime curvature can drive the production of dark matter during reheating, and accurately quantifying this requires the use of both non-perturbative and non-equilibrium methods. This tachyonic instability has previously been studied using 2-particle irreducible -formalism in the Hartree approximation. However, modelling the non-thermal dark matter distribution and its subsequent evolution requires accounting also for momentum exchanging collisions. I will detail a self-consistent approximation scheme for reducing the beyond-Hartree 2PI equations of motion to a generalized quantum Boltzmann equation, which can then be solved with standard methods. The approach can be used on both stable and unstable field excitations. This presentation is based on a theory-focused followup to arXiv:2406.17468, whose preprint will be available in May.