Graviton Corrections to Vacuum Polarization during Inflation

TL;DR

This paper calculates quantum gravitational effects on vacuum polarization during inflation, showing that photon electric fields are secularly suppressed, which could influence electromagnetic phenomena in the early universe.

Contribution

It provides the first fully renormalized one-loop quantum gravitational correction to vacuum polarization on de Sitter space and analyzes its impact on electromagnetic fields during inflation.

Findings

Quantum gravitational corrections lead to secular suppression of electric fields during inflation.

The renormalized vacuum polarization can modify Maxwell's equations in an inflationary background.

Photon electric field strengths decrease over time due to gravitational effects.

Abstract

We use dimensional regularization to compute the one loop quantum gravitational contribution to the vacuum polarization on de Sitter background. Adding the appropriate BPHZ counterterms gives a fully renormalized result which can be used to quantum correct Maxwell's equations. We use the Hartree approximation to argue that the electric field strengths of photons experience a secular suppression during inflation.