Graviton production in anti-de Sitter braneworld cosmology: A fully consistent treatment of the boundary condition

TL;DR

This paper develops a new approach to analyze graviton production in anti-de Sitter braneworld cosmology, accounting for boundary conditions more accurately and confirming previous results at low brane velocities.

Contribution

It introduces a fully consistent treatment of boundary conditions in graviton production, improving upon previous approximations by including terms linear in brane velocity.

Findings

Previous results remain valid at low brane velocities.

The new approach accurately incorporates boundary conditions.

The study enhances understanding of graviton vacuum modifications.

Abstract

In recent work by two of us, [Durrer & Ruser, PRL 99, 071601 (2007); Ruser & Durrer PRD 76, 104014 (2007)], graviton production due to a moving spacetime boundary (braneworld) in a five dimensional bulk has been considered. In the same way as the presence of a conducting plate modifies the electromagnetic vacuum, the presence of a brane modifies the graviton vacuum. As the brane moves, the time dependence of the vacuum leads to particle creation via the so called 'dynamical Casimir effect'. In our previous work a term in the boundary condition which is linear in the brane velocity has been neglected. In this work we develop a new approach which overcomes this approximation. We show that the previous results are not modified if the brane velocity is low.