Late-time asymptotic dynamics of Bianchi VIII cosmologies

Abstract

In this paper we give, for the first time, a complete description of the late-time evolution of non-tilted spatially homogeneous cosmologies of Bianchi type VIII. The source is assumed to be a perfect fluid with equation of state $p=(\gamma -1)\mu$, where $\gamma$ is a constant which satisfies $1\le \gamma \le 2$. Using the orthonormal frame formalism and Hubble-normalized variables, we rigorously establish the limiting behaviour of the models at late times, and give asymptotic expansions for the key physical variables. The main result is that asymptotic self-similarity breaking occurs, and is accompanied by the phenomenon of `Weyl curvature dominance', characterized by the divergence of the Hubble-normalized Weyl curvature at late times.

22 pages, 3 figures, submitted to Class. Quantum Grav.; updated references