Sofic measures and densities of level sets

Abstract

The Bernoulli convolution associated to the real $β>1$ and the probability vector $(p_0,..,p_{d-1})$ is a probability measure $η_{β,p}$ on $\mathbb R$, solution of the self-similarity relation $\displaystyleη=\sum_{k=0}^{d-1}p_k\cdotη\circ S_k$ where $S_k(x)=\frac{x+k}β$. If $β$ is an integer or a Pisot algebraic number with finite Rényi expansion, $η_{β,p}$ is sofic and a Markov chain is naturally associated. If $β=b\in\mathbb N$ and $p_0=...=p_{d-1}=\frac1d$, the study of $η_{b,p}$ is close to the study of the order of growth of the number of representations in base $b$ with digits in $\{0,1,..,d-1\}$. In the case $b=2$ and $d=3$ it has also something to do with the metric properties of the continued fractions.