The Exact WKB and the Landau-Zener transition for asymmetry in cosmological particle production

TL;DR

This paper explores how the Exact WKB method combined with Landau-Zener transition analysis clarifies asymmetry in cosmological particle production, especially when rapid, symmetry-violating interactions are involved.

Contribution

It introduces a novel application of Exact WKB analysis to cosmological particle production, highlighting its importance in accurately understanding non-perturbative effects.

Findings

Perturbative analysis can misrepresent the structure of Stokes lines.

Exact WKB analysis helps avoid discrepancies in non-perturbative regimes.

The combined approach clarifies asymmetry generation in cosmology.

Abstract

Cosmological particle production by a time-dependent scalar field is common in cosmology. We focus on the mechanism of asymmetry production when interaction explicitly violates symmetry and its motion is rapid enough to create particles by itself. Combining the exact WKB analysis and the Landau-Zener transition, we point out that perturbation before the non-perturbative analysis may drastically change the structure of the Stokes lines of the theory. The Exact WKB can play an important role in avoiding such discrepancies.