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

Naureen Goheer·Peter K. S. Dunsby·Alan Coley·Marco Bruni
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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 $γ> 4/3$.

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Naureen Goheer, Peter K. S. Dunsby, Alan Coley, Marco Bruni. 2004-08-11. Large-scale perturbations on the brane and the isotropy of the cosmological singularity. https://doi.org/10.1103/physrevd.70.123517

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