A Local Effective Action for Photon-Gravity Interactions

TL;DR

This paper develops a new local effective action for photon-gravity interactions in curved spacetime, capturing quantum effects like vacuum polarization and superluminal photon propagation, crucial for understanding high-frequency photon behavior.

Contribution

It introduces a comprehensive, local effective action valid to all orders in derivatives, extending previous models for quantum photon-gravity interactions.

Findings

Provides a local effective action valid to all derivative orders.

Enables detailed analysis of high-frequency photon propagation in gravitational fields.

Addresses quantum effects like vacuum polarization and superluminal propagation.

Abstract

Quantum phenomena such as vacuum polarisation in curved spacetime induce interactions between photons and gravity with quite striking consequences, including the violation of the strong equivalence principle and the apparent prediction of `superluminal' photon propagation. These quantum interactions can be encoded in an effective action. In this paper, we extend previous results on the effective action for QED in curved spacetime due to Barvinsky, Vilkovisky and others and present a new, local effective action valid to all orders in a derivative expansion, as required for a full analysis of the quantum theory of high-frequency photon propagation in gravitational fields.