We consider random perturbations of discrete-time dynamical systems. We give
sufficient conditions for the stochastic stability of certain classes of maps,
in a strong sense. This improves the main result in J. F. Alves, V.
We consider a quite broad class of maps on compact manifolds of arbitrary
dimension possibly admitting critical points,discontinuities and singularities.
Under some mild nondegeneracy assumptions we show that (f) admits an induced
Gibbs-Markov map with integrable inducing times if and only if it has an
ergodic invariant probability measure which is absolutely continuous with
respect to the Riemannian volume and has all Lyapunov exponents positive.
We consider a partially hyperbolic set $K$ on a Riemannian manifold $M$ whose
tangent space splits as $T_K M=E^{cu}\oplus E^{s}$, for which the
centre-unstable direction $E^{cu}$ expands non-uniformly on some local unstable
disk. We show that under these assumptions $f$ induces a Gibbs-Markov
structure. Moreover, the decay of the return time function can be controlled in
terms of the time typical points need to achieve some uniform expanding
behavior in the centre-unstable direction.
We consider a partially hyperbolic set $K$ on a Riemannian manifold $M$ whose
tangent space splits as $T_K M=E^{cu}\oplus E^{s}$, for which the
centre-unstable direction $E^{cu}$ expands non-uniformly on some local unstable
disk. We show that under these assumptions $f$ induces a Gibbs-Markov
structure. Moreover, the decay of the return time function can be controlled in
terms of the time typical points need to achieve some uniform expanding
behavior in the centre-unstable direction.