Schwinger effect in axion inflation on a lattice

TL;DR

This paper presents lattice simulations of axion inflation, showing how Schwinger pair production influences gauge field evolution and impacts magnetogenesis prospects.

Contribution

First lattice simulation incorporating Schwinger pair production in axion inflation, revealing its effect on gauge fields and magnetogenesis.

Findings

Schwinger currents grow due to tachyonic gauge field amplification.

Universal conductivity and magnetic field values at backreaction onset.

Schwinger effect saturates gauge field production, reducing magnetogenesis viability.

Abstract

We present the first lattice simulations of the nonlinear evolution after axion inflation by self-consistently incorporating currents arising from Schwinger pair production. The tachyonically amplified gauge fields trigger the growth of Schwinger currents, leading to universal values for the conductivity and magnetic field at the onset of strong backreaction and subsequent quenching of gauge field production. We show that the Schwinger effect (prematurely) saturates gauge field production, thereby diminishing the prospects of high scale axion inflation magnetogenesis as a viable solution for blazar observations.