A dichotomy for measures of maximal entropy near time-one maps of transitive Anosov flows (original) (raw)

A relation between entropy and transitivity of Anosov diffeomorphisms

Journal of Dynamical and Control Systems, 2022

It is known that transitive Anosov diffeomorphisms have a unique measure of maximal entropy (MME). Here we discuss the converse question. Under suitable hypothesis on Lyapunov exponents on the set of periodic points and the structure of the MME we get transitivity of C 1 −Anosov diffeomorphisms.

On the number of ergodic measures of maximal entropy for partially hyperbolic diffeomorphisms with compact center leaves

Mathematische Zeitschrift, 2022

In this paper, we study the number of ergodic measures of maximal entropy for partially hyperbolic diffeomorphisms defined on 3−torus with compact center leaves. Assuming the existence of a periodic leaf with Morse-Smale dynamics we prove a sharp upper bound for the number of maximal measures in terms of the number of sources and sinks of Morse-Smale dynamics. A well-known class of examples for which our results apply are the so-called Kan-type diffeomorphisms admitting physical measures with intermingled basins.

Diffeomorphisms with positive metric entropy

Publications mathématiques de l'IHÉS, 2016

We obtain a dichotomy for C 1-generic, volume-preserving diffeomorphisms: either all the Lyapunov exponents of almost every point vanish or the volume is ergodic and non-uniformly Anosov (i.e. nonuniformly hyperbolic and the splitting into stable and unstable spaces is dominated). This completes a program first put forth by Ricardo Mañé.

A lower bound for topological entropy of generic non-Anosov symplectic diffeomorphisms

Ergodic Theory and Dynamical Systems, 2013

We prove that a C1{C}^{1} C1 generic symplectic diffeomorphism is either Anosov or its topological entropy is bounded from below by the supremum over the smallest positive Lyapunov exponent of its periodic points. We also prove that C1{C}^{1} C1 generic symplectic diffeomorphisms outside the Anosov ones do not admit symbolic extension and, finally, we give examples of volume preserving surface diffeomorphisms which are not points of upper semicontinuity of the entropy function in the C1{C}^{1} C1 topology.

On the Bernoulli property for certain partially hyperbolic diffeomorphisms

arXiv (Cornell University), 2016

We address the classical problem of equivalence between Kolmogorov and Bernoulli property of smooth dynamical systems. In a natural class of volume preserving partially hyperbolic diffeomorphisms homotopic to Anosov ("derived from Anosov") on 3-torus, we prove that Kolmogorov and Bernoulli properties are equivalent. In our approach, we propose to study the conditional measures of volume along central foliation to recover fine ergodic properties for partially hyperbolic diffeomorphisms. As an important consequence we obtain that there exists an almost everywhere conjugacy between any volume preserving derived from Anosov diffeomorphism of 3-torus and its linearization. Our results also hold in higher dimensional case when central bundle is one dimensional and stable and unstable foliations are quasi-isometric.

Symplectomorphisms with positive metric entropy

Proceedings of the London Mathematical Society, 2022

We obtain a dichotomy for C 1-generic symplectomorphisms: either all the Lyapunov exponents of almost every point vanish, or the map is partially hyperbolic and ergodic with respect to volume. This completes a program first put forth by Ricardo Mañé. A main ingredient in our proof is a generalization to partially hyperbolic invariant sets of the main result in [DW] that stable accessibility is C 1 dense among partially hyperbolic diffeomorphisms.

ENTROPY AND MEASURE DEGENERACY FOR FLOWS

2008

In discrete dynamical systems topological entropy is a topological invariant and a measurement of the complexity of a system. In continuous dynamical systems, in general, topological entropy defined as usual by the time one map does not work so well in what concerns these aspects. The point is that the natural notion of equivalence in the discrete case is topological conjugacy which preserves time while in the continuous case the natural notion of equivalence is topological equivalence which allow reparametrizations of the orbits. The main issue happens in the case that the system has fixed points and will be our subject here.

Entropy of flows, revisited

Boletim Da Sociedade Brasileira De Matematica, 1999

We introduce a concept of measure-theoretic entropy for flows and study its invariance under measure-theoretic equivalences. Invariance properties of the corresponding topological entropy is studied too. We also answer a question posed by Bowen-Walters in [3] concerning the equality between the topological entropy of the time-one map of an expansive flow and the time-one map of its symbolic suspension.