# Schwinger Mechanism During Inflation

## TL;DR

This paper investigates the efficiency of the Schwinger mechanism during inflation, finding it to be highly inefficient for creating charged pairs, with negligible effects on large-scale magnetogenesis.

## Contribution

It provides a detailed analysis of the Schwinger mechanism's role during inflation, contrasting it with previous models that assumed a constant electric field background.

## Key findings

- Schwinger mechanism is highly inefficient during inflation.
- Charged pair production is negligible on large scales.
- Back-reaction effects on magnetogenesis are minimal.

## Abstract

We revisit the efficiency of Schwinger mechanism in creating charged pairs during inflation. We consider a minimal setup of inflation in which the inflaton field is a complex scalar field charged under a $U(1)$ gauge field. There is a time dependent conformal coupling which pumps energy from the inflaton field to the gauge field to furnish a nearly constant background electric field energy density to drive the Schwinger mechanism. The coupling between the gauge field and the scalar field induces a time dependent effective mass for the inflaton field. The requirement of a long period of slow-roll inflation causes the Schwinger mechanism to be highly inefficient during inflation. The non-perturbative Schwinger mechanism can be relevant only towards the end of inflation and only on very small scales. This is in contrast to hypothetical models studied in literature in which the complex scalar field is a test field and a constant electric field is imposed on the dS background by hand. We calculate the number of pairs of charged particles created perturbatively during inflation. We show that it is proportional to the amplitude of the quadrupolar statistical anisotropy and it is very small. Consequently, the back-reactions of created particles on magnetogenesis on large scales are negligible.