BKL conjecture in Bianchi VIII and IX with the ultrarelativistic fluid

We rigorously verify that in the spatially homogeneous spacetimes (Bianchi VIII and IX), the presence of matter does not affect the oscillatory behavior of the solutions to the Einstein field equations as first conjectured by Belinski, Khalatnikov, and Lifshitz (BKL) in 1970. This paper is an extension of the paper by Reiterer and Trubowitz (arXiv 1005.4908) and uses the same formalism. We use the ultrarelativistic equation of state.