One Loop Field Strengths of Charges and Dipoles on a Locally de Sitter Background

TL;DR

This paper calculates the one-loop quantum corrections to electric and magnetic fields of charges and dipoles in a de Sitter universe, revealing strong vacuum polarization effects during inflation.

Contribution

It provides the first detailed computation of one-loop vacuum polarization effects on fields in a de Sitter background using the Schwinger-Keldysh formalism.

Findings

Vacuum polarization becomes nonperturbatively strong during inflation.

Results support the picture of an inflating universe filled with charged particles.

Computed fields are consistent across different coordinate systems.

Abstract

We use the one loop vacuum polarization induced by scalar quantum electrodynamics to compute the electric and magnetic fields of point charges and magnetic dipoles on a locally de Sitter background. Our results are consistent with the physical picture of an inflating universe filling with a vast sea of charged particles as more and more virtual infrared scalar are ripped out of the vacuum. One consequence is that vacuum polarization quickly becomes nonperturbatively strong. Our computation employs the Schwinger-Keldysh effective field equations and is done in flat, conformal coordinates. Results are also obtained for static coordinates.