Non-Abelian gauge preheating

Abstract

We study preheating in models where a scalar inflaton is directly coupled to a non-Abelian $SU(2)$ gauge field. In particular, we examine $m^2{\varphi }^2$ inflation with a conformal, dilaton-like coupling to the non-Abelian sector. We describe a numerical scheme that combines lattice gauge theory with standard finite difference methods applied to the scalar field. We show that a significant tachyonic instability allows for efficient preheating, which is parametrically suppressed by increasing the non-Abelian self-coupling. Additionally, we comment on the technical implementation of the evolution scheme and setting initial conditions.

Comments: v2: 15 pages, 9 figures; references and minor clarifications added, matches PRD version