On Quantum Radiation in Curved Spacetime

TL;DR

This paper investigates how curved spacetime influences quantum vacuum decay, revealing that gravitational fields polarize the vacuum, discretize its spectrum, and induce particle-antiparticle pair creation with a thermal spectrum.

Contribution

It introduces a detailed analysis of vacuum polarization effects and the quantum origin of particle creation in curved spacetime, linking gravitational energy to vacuum decay processes.

Findings

Gravitational fields polarize the vacuum and discretize its spectrum.

Vacuum decay involves pair creation of particles and antiparticles.

The particle creation spectrum is thermal, governed by gravitational energy.

Abstract

In the context of quantum field theories in curved spacetime, we compute the effective action of the transition amplitude from vacuum to vacuum in the presence of an external gravitational field. The imaginary part of resulted effective action determines the probability of vacuum decay via quantum tunneling process, giving the rate and spectrum of particle creations. We show that gravitational field polarizes vacuum and discretizes its spectrum for such a polarization gains gravitational energy. On the basis of gravitational vacuum polarization, we discuss the quantum origin of vacuum decay in curved spacetime as pair-creations of particles and anti-particles. The thermal spectrum of particle creations is attributed to (i) the CPT invariance of pair-creations(annihilations) from(into) vacuum and (ii) vacuum acts as a reserve with the temperature determined by gravitational energy-gain.