English

An algorithm for the word entropy

Dynamical Systems 2018-03-16 v1

Abstract

For any infinite word ww on a finite alphabet AA, the complexity function pwp_w of ww is the sequence counting, for each non-negative nn, the number pw(n)p_w(n) of words of length nn on the alphabet AA that are factors of the infinite word ww and the the entropy of ww is the quantity E(w)=limn1nlogpw(n)E(w)=\lim\limits_{n\to\infty}\frac 1n\log p_w(n). For any given function ff with exponential growth, Mauduit and Moreira introduced in [MM17] the notion of word entropy EW(f)=sup{E(w),wAN,pwf}E_W(f) = \sup \{E(w), w \in A^{{\mathbb N}}, p_w \le f \} and showed its links with fractal dimensions of sets of infinite sequences with complexity function bounded by ff. The goal of this work is to give an algorithm to estimate with arbitrary precision EW(f)E_W(f) from finitely many values of ff.

Keywords

Cite

@article{arxiv.1803.05533,
  title  = {An algorithm for the word entropy},
  author = {Carlos Gustavo Moreira and Christian Mauduit and Sébastien Ferenczi},
  journal= {arXiv preprint arXiv:1803.05533},
  year   = {2018}
}
R2 v1 2026-06-23T00:53:35.873Z