English

A small morphism giving Abelian repetition threshold less than 2

Combinatorics 2023-12-29 v1 Formal Languages and Automata Theory

Abstract

It is known that there are infinite words over finite alphabets with Abelian repetition threshold arbitrarily close to 1; however, the construction previously used involves huge alphabets. In this note we give a short cyclic morphism (length 13) over an 8-letter alphabet yielding an Abelian repetition threshold less than 1.8.

Keywords

Cite

@article{arxiv.2312.16665,
  title  = {A small morphism giving Abelian repetition threshold less than 2},
  author = {James D. Currie and Narad Rampersad},
  journal= {arXiv preprint arXiv:2312.16665},
  year   = {2023}
}

Comments

12 pages

R2 v1 2026-06-28T14:03:09.192Z