English

A note on the relation between the metric entropy and the generalized fractal dimensions of invariant measures

Dynamical Systems 2019-10-15 v2

Abstract

We investigate in this work some situations where it is possible to estimate or determine the upper and the lower qq-generalized fractal dimensions Dμ±(q)D^{\pm}_{\mu}(q), qRq\in\mathbb{R}, of invariant measures associated with continuous transformations over compact metric spaces. In particular, we present an alternative proof of Young's Theorem~\cite{Young} for the generalized fractal dimensions of the Bowen-Margulis measure associated with a C1+αC^{1+\alpha}-Axiom A system over a two-dimensional compact Riemannian manifold MM. We also present estimates for the generalized fractal dimensions of an ergodic measure for which Brin-Katok's Theorem is satisfied punctually, in terms of its metric entropy. Furthermore, for expansive homeomorphisms (like C1C^1-Axiom A systems), we show that the set of invariant measures such that Dμ+(q)=0D_\mu^+(q)=0 (q1q\ge 1), under a hyperbolic metric, is generic (taking into account the weak topology). We also show that for each s[0,1)s\in [0,1), Dμ+(s)D^{+}_{\mu}(s) is bounded above, up to a constant, by the topological entropy, also under a hyperbolic metric. Finally, we show that, for some dynamical systems, the metric entropy of an invariant measure is typically zero, settling a conjecture posed by Sigmund in~\cite{Sigmund1974} for Lipschitz transformations which satisfy the specification property.

Keywords

Cite

@article{arxiv.1908.00998,
  title  = {A note on the relation between the metric entropy and the generalized fractal dimensions of invariant measures},
  author = {Alexander Condori and Silas L. Carvalho},
  journal= {arXiv preprint arXiv:1908.00998},
  year   = {2019}
}