  Stable accessibility for partially hyperbolic diffeomorphisms is central to
their ergodic theory, and we establish its \(C^1\)-density among 1. all, 2.
volume-preserving, 3. symplectic, and 4. contact partially hyperbolic flows.
  As applications, we obtain in each of these 4 categories \(C^1\)-density of
\(C^1\)-stable topological transitivity, ergodicity, and triviality of the
centralizer.
