# The dynamical Casimir effect in braneworlds

## TL;DR

This paper investigates graviton production due to brane motion in higher-dimensional warped spacetimes, showing KK particles behave like stiff matter and discussing the implications of graviton backreaction in bouncing brane scenarios.

## Contribution

It demonstrates that KK particles scale like stiff matter and analyzes graviton production in bouncing branes within warped five-dimensional anti-de Sitter space.

## Key findings

- KK particles behave like stiff matter during expansion
- Backreaction from gravitons may be significant in realistic bouncing scenarios
- Numerical simulations support the main theoretical conclusions

## Abstract

In braneworld cosmology the expanding Universe is realized as a brane moving through a warped higher-dimensional spacetime. Like a moving mirror causes the creation of photons out of vacuum fluctuations, a moving brane leads to graviton production. We show that, very generically, Kaluza-Klein (KK) particles scale like stiff matter with the expansion of the Universe and can therefore not represent the dark matter in a warped braneworld. We present results for the production of massless and KK gravitons for bouncing branes in five-dimensional anti de Sitter space. We find that for a realistic bounce the back reaction from the generated gravitons will be most likely relevant. This letter summarizes the main results and conclusions from numerical simulations which are presented in detail in a long paper [M.Ruser and R. Durrer, Phys. Rev. D 76, 104014 (2007), arXiv:0704.0790]