Long hitting time, slow decay of correlations and arithmetical properties
Abstract
Let be the time needed for a point to enter for the first time in a ball centered in , with small radius . We construct a class of translations on the two torus having particular arithmetic properties (Liouville components with intertwined denominators of convergents) not satisfying a logarithm law, i.e. such that for generic \liminf_{r\to 0} \frac{\log \tau_r(x,x_0)}{-\log r} = \infty. By considering a suitable reparametrization of the flow generated by a suspension of this translation, using a previous construction by Fayad, we show the existence of a mixing system on three torus having the same properties. The speed of mixing of this example must be subpolynomial, because we also show that: in a system having polynomial decay of correlations the above ratio of logarithms (which is also called the lower hitting time indicator) is bounded (it is a function of the local dimension and the speed of correlation decay). More generally, this shows that reparametrizations of torus translations having a Liouville component cannot be polynomially mixing.
Keywords
Cite
@article{arxiv.0801.3109,
title = {Long hitting time, slow decay of correlations and arithmetical properties},
author = {Stefano Galatolo and Pietro Peterlongo},
journal= {arXiv preprint arXiv:0801.3109},
year = {2009}
}
Comments
19 pages, in the new version some misprint and small errors are corrected