English

Estimates on the dimension of self-similar measures with overlaps

Dynamical Systems 2021-09-06 v2 Classical Analysis and ODEs

Abstract

In this paper, we provide an algorithm to estimate from below the dimension of self-similar measures with overlaps. As an application, we show that for any β(1,2) \beta\in(1,2) , the dimension of the Bernoulli convolution μβ \mu_\beta satisfies dim(μβ)0.9804085, \dim (\mu_\beta) \geq 0.9804085, which improves a previous uniform lower bound 0.820.82 obtained by Hare and Sidorov \cite{HareSidorov2018}. This new uniform lower bound is very close to the known numerical approximation 0.98040931953±1011 0.98040931953\pm 10^{-11} for dimμβ3\dim \mu_{\beta_3}, where β31.839286755214161 \beta_{3} \approx 1.839286755214161 is the largest root of the polynomial x3x2x1 x^{3}-x^{2}-x-1. Moreover, the infimum infβ(1,2)dim(μβ)\inf_{\beta\in (1,2)}\dim (\mu_\beta) is attained at a parameter β\beta_* in a small interval (β3108,β3+108). (\beta_{3} -10^{-8}, \beta_{3} + 10^{-8}). When β\beta is a Pisot number, we express dim(μβ)\dim(\mu_\beta) in terms of the measure-theoretic entropy of the equilibrium measure for certain matrix pressure function, and present an algorithm to estimate dim(μβ)\dim (\mu_\beta) from above as well.

Keywords

Cite

@article{arxiv.2103.01700,
  title  = {Estimates on the dimension of self-similar measures with overlaps},
  author = {De-Jun Feng and Zhou Feng},
  journal= {arXiv preprint arXiv:2103.01700},
  year   = {2021}
}

Comments

Some minor changes and clarifications. To appear in J. Lond. Math. Soc