Hausdorff dimension of real numbers with bounded digit averages
Herman’s last geometric theorem
We present a proof of Herman’s Last Geometric Theorem asserting that if is a smooth diffeomorphism of the annulus having the intersection property, then any given -invariant smooth curve on which the rotation number of is Diophantine is accumulated by a positive measure set of smooth invariant curves on which is smoothly conjugated to rotation maps. This implies in particular that a Diophantine elliptic fixed point of an area preserving diffeomorphism of the plane is stable. The remarkable...
Higher order Schwarzian derivatives in interval dynamics
We introduce an infinite sequence of higher order Schwarzian derivatives closely related to the theory of monotone matrix functions. We generalize the classical Koebe lemma to maps with positive Schwarzian derivatives up to some order, obtaining control over derivatives of high order. For a large class of multimodal interval maps we show that all inverse branches of first return maps to sufficiently small neighbourhoods of critical values have their higher order Schwarzian derivatives positive up...
High-order phase transitions in the quadratic family
We give the first example of a transitive quadratic map whose real and complex geometric pressure functions have a high-order phase transition. In fact, we show that this phase transition resembles a Kosterlitz-Thouless singularity: Near the critical parameter the geometric pressure function behaves as near , before becoming linear. This quadratic map has a non-recurrent critical point, so it is non-uniformly hyperbolic in a strong sense.
Homeomorphisms of inverse limit spaces of one-dimensional maps
We present a new technique for showing that inverse limit spaces of certain one-dimensional Markov maps are not homeomorphic. In particular, the inverse limit spaces for the three maps from the tent family having periodic kneading sequence of length five are not homeomorphic.
Homoclinic bifurcations and uniform hyperbolicity for three-dimensional flows
Horseshoe in a class of planar mappings.
Hubbard trees
We provide a full classification of postcritically finite polynomials as dynamical systems by means of Hubbard trees. The information encoded in these objects is solid enough to allow us recover all the relevant statical and dynamical aspects of the corresponding Julia sets.
Hyperbolicity in a class of one-dimensional maps.
In this paper we provide a direct proof of hyperbolicity for a class of one-dimensional maps on the unit interval. The maps studied are degenerate forms of the standard quadratic map on the interval. These maps are important in understanding the Newhouse theory of infinitely many sinks due to homoclinic tangencies in two dimensions.
Hyperbolicity of renormalization of critical circle maps