The asymptotic behaviour of tilted Bianchi type VI0 universes

We study the asymptotic behaviour of the Bianchi type VI₀ universes with a tilted γ-law perfect fluid. The late-time attractors are found for the full seven-dimensional state space and for several interesting invariant subspaces. In particular, it is found that for the particular value of the equation of state parameter, γ = 6/5, there exists a bifurcation line which signals a transition of stability between a non-tilted equilibrium point and an extremely tilted equilibrium point. The initial singular regime is also discussed and we argue that the initial behaviour is chaotic for γ < 2.