Large-scale perturbations on the brane and the isotropy of the cosmological singularity

Goheer, Naureen; Dunsby, Peter K S; Coley, Alan; Bruni, Marco

Large-scale perturbations on the brane and the isotropy of the cosmological singularity

Journal Article

2004

Journal Title

Physical Review D - Particles and Fields

Link to Journal

https://dx.doi.org/10.1103/PhysRevD.70.123517

Department

Department of Mathematics and Applied Mathematics

Faculty

Faculty of Science

Abstract

We present the complete set of propagation and constraint equations for the kinematic and non-local first order quantities which describe general linear inhomogeneous and anisotropic perturbations of a flat FRW braneworld with vanishing cosmological constant and decompose them in the standard way into their scalar, vector and tensor contributions. A detailed analysis of the perturbation dynamics is performed using dimensionless variables that are specially tailored for the different regimes of interest; namely, the low energy GR regime, the high energy regime and the dark energy regime. Tables are presented for the evolution of all the physical quantities, making it easy to do a detailed comparison of the past asymptotic behaviour of the perturbations of these models. We find results that exactly match those obtained in the analysis of the spatially inhomogeneous $G_{2}$ braneworld cosmologies presented recently; i.e., that isotropization towards the ${cal F}_b$ model occurs for $gamma > 4/3$.