Gravitational particle production in braneworld cosmology

TL;DR

This paper explores how braneworld cosmology's faster early universe expansion enhances gravitational particle production, potentially creating many weakly interacting particles, unlike in standard cosmology.

Contribution

It demonstrates that in braneworld cosmology, the increased expansion rate makes gravitational particle production more efficient, which is not possible in standard cosmology.

Findings

Enhanced particle production in braneworld scenarios

Potential abundance of weakly interacting particles

Implications for early universe cosmology

Abstract

Gravitational particle production in time variable metric of an expanding universe is efficient only when the Hubble parameter $H$ is not too small in comparison with the particle mass. In standard cosmology, the huge value of the Planck mass $M_{Pl}$ makes the mechanism phenomenologically irrelevant. On the other hand, in braneworld cosmology the expansion rate of the early universe can be much faster and many weakly interacting particles can be abundantly created. Cosmological implications are discussed.