English

Freeness of Sch\"utzenberger groups of primitive substitutions

Group Theory 2022-12-20 v1

Abstract

Our main goal is to study the freeness of Sch\"utzenberger groups defined by primitive substitutions. Our findings include a simple freeness test for these groups, which is applied to exhibit a primitive invertible substitution with corresponding non-free Sch\"utzenberger group. This constitutes a counterexample to a result of Almeida dating back to 2005. We also give some early results concerning relative freeness of Sch\"utzenberger groups, a question which remains largely unexplored.

Keywords

Cite

@article{arxiv.2109.11957,
  title  = {Freeness of Sch\"utzenberger groups of primitive substitutions},
  author = {Herman Goulet-Ouellet},
  journal= {arXiv preprint arXiv:2109.11957},
  year   = {2022}
}