English

Clustering and Arnoux-Rauzy words

Dynamical Systems 2023-05-31 v1

Abstract

We characterize the clustering of a word under the Burrows-Wheeler transform in terms of the resolution of a bounded number of bispecial factors belonging to the language generated by all its powers. We use this criterion to compute, in every given Arnoux-Rauzy language on three letters, an explicit bound KK such that each word of length at least KK is not clustering; this bound is sharp for a set of Arnoux-Rauzy languages including the Tribonacci one. In the other direction, we characterize all standard Arnoux-Rauzy clustering words, and all perfectly clustering Arnoux-Rauzy words. We extend some results to episturmian languages, characterizing those which produce infinitely many clustering words, and to larger alphabets.

Keywords

Cite

@article{arxiv.2305.18986,
  title  = {Clustering and Arnoux-Rauzy words},
  author = {Sébastien Ferenczi and Luca Q. Zamboni},
  journal= {arXiv preprint arXiv:2305.18986},
  year   = {2023}
}
R2 v1 2026-06-28T10:50:35.366Z