The density of nonuniform hyperbolicity in conservative diffeomorphisms
arXiv:1508.06714
Abstract
Let $\Diff^{ r}_m(M)$ be the set of volume-preserving diffeomorphisms on a compact Riemannian manifold (). In this paper, we prove that the diffeomorphisms without zero Lyapunov exponents on a set of positive volume are dense in $\Diff^{ r}_m(M), r\geq 1$. We also prove a weaker result for symplectic diffeomorphisms saying that the symplectic diffeomorphisms with non-zero Lyapunov exponents on a set of positive volume are dense in .
13 pages