English

The entropy of alpha-continued fractions: numerical results

Dynamical Systems 2015-05-14 v1 Number Theory

Abstract

We consider the one-parameter family of interval maps arising from generalized continued fraction expansions known as alpha-continued fractions. For such maps, we perform a numerical study of the behaviour of metric entropy as a function of the parameter. The behaviour of entropy is known to be quite regular for parameters for which a matching condition on the orbits of the endpoints holds. We give a detailed description of the set M where this condition is met: it consists of a countable union of open intervals, corresponding to different combinatorial data, which appear to be arranged in a hierarchical structure. Our experimental data suggest that the complement of M is a proper subset of the set of bounded-type numbers, hence it has measure zero. Furthermore, we give evidence that the entropy on matching intervals is smooth; on the other hand, we can construct points outside of M on which it is not even locally monotone.

Keywords

Cite

@article{arxiv.0912.2329,
  title  = {The entropy of alpha-continued fractions: numerical results},
  author = {Carlo Carminati and Stefano Marmi and Alessandro Profeti and Giulio Tiozzo},
  journal= {arXiv preprint arXiv:0912.2329},
  year   = {2015}
}

Comments

33 pages, 14 figures