Conformally-flat gravitational analogues to the Schwinger effect

TL;DR

This paper explores particle creation in conformally flat spacetimes using heat-kernel techniques, establishing an analogy with Yukawa theories in Minkowski space, and uncovers new gravitational analogues of the Schwinger effect.

Contribution

It introduces a novel framework linking quantum scalar fields in curved spacetime to Yukawa theories in flat space, enabling analysis of particle creation at strong curvature.

Findings

Particle production rates confirmed in radiation-dominated universes.

Exact gravitational analogues of the Schwinger effect discovered.

Framework includes nonconformal curvature couplings.

Abstract

We study particle creation for scalar fields in conformally flat spacetimes using resummed heat-kernel techniques. We make use of an analogy between quantum scalar fields in conformally flat spacetimes and scalar field theories with a Yukawa coupling in Minkowski space. The correspondence holds exactly at the level of the effective action and includes nonconformal curvature couplings. This framework provides access to particle creation at strong curvature. In a radiation dominated universe, the particle production rates in arbitrary dimensions are independently confirmed through explicit calculations of the Bogoliubov coefficients. We also find new exact gravitational analogues of the Schwinger effect in quantum field theory in curved spacetime.