Axion Monodromy Inflation, Trapping Mechanisms and the Swampland

TL;DR

This paper investigates how particle production affects axion monodromy inflation, identifying conditions under which the dynamics align with swampland constraints, including scenarios of trapped inflation via moduli fields.

Contribution

It analyzes the impact of particle production in axion monodromy models and explores conditions for consistent trapped inflation within swampland constraints.

Findings

Particle production can be negligible or trap the inflaton, affecting inflation dynamics.

Trapped inflation via moduli fields is possible with strong coupling, consistent with swampland.

Large field spacing prevents significant particle production effects.

Abstract

We study the effects of particle production on the evolution of the inflaton field in an axion monodromy model with the goal of discovering in which situations the resulting dynamics will be consistent with the {\it swampland constraints}. In the presence of a modulated potential the evolving background field (solution of the inflaton homogeneous in space) induces the production of long wavelength inflaton fluctuation modes. However, this either has a negligible effect on the inflaton dynamics (if the field spacing between local minima of the modulated potential is large), or else it traps the inflaton in a local minimum and leads to a graceful exit problem. On the other hand, the production of moduli fields at enhanced symmetry points can lead to a realization of {\it trapped inflation} consistent with the swampland constraints, as long as the coupling between the inflaton and the moduli fields is sufficiently large.