Exponential mixing via invariant foliations and relatively Anosov homeomorphisms
We prove that every closed manifold of dimension $n\ge 4$ which admits a singular $2$-foliation (a foliation by closed surfaces whose quotient is a punctured $(n-2)$-torus) supports a volume-preserving homeomorphism with exponential decay of correlations for Hölder observables. The proof introduces a class of systems called relatively Anosov homeomorphisms, which fails differentiability only at the singular set. We apply a general dichotomy that bounds the decay of correlations of any homeomorphism preserving an invariant foliation by the maximum of the decay rates of the quotient dynamics and of the leafwise cycles. This dichotomy is of independent interest and yields, as immediate consequences, decay rates for product systems, skew products, partially hyperbolic diffeomorphisms with compact center leaves, finite covers, and extensions by expanding fibre maps. We then prove this gives a positive answer to a conjecture of Dolgopyat and Pesin regarding the realization problem for exponential decay of correlations over a large class of manifolds for which there were no known systems with exponential decay of correlations. In particular, we construct infinitely many pairwise non-homeomorphic closed $4$-manifolds which admit a volume-preserving homeomorphism with exponential decay of correlations, albeit not supporting either Anosov diffeomorphisms or strong partially hyperbolic diffeomorphisms.