English

On the rank of a Coxeter group

Group Theory 2007-06-28 v1

Abstract

Let W be a Coxeter group with Coxeter generators S. The rank of the Coxeter system (W,S) is the cardinality |S| of S. The Coxeter system (W,S) has finite rank if and only if W is finitely generated. If (W,S) has infinite rank, then |S| = |W|, since every element of W is represented by a finite product of elements of S. Thus if W is not finitely generated, the rank of (W,S) is uniquely determined by W. If W is finitely generated, then W may have sets of Coxeter generators S and S' of different ranks. In this paper, we determine the set of all possible ranks for an arbitrary finitely generated Coxeter group W.

Keywords

Cite

@article{arxiv.0706.3911,
  title  = {On the rank of a Coxeter group},
  author = {Michael L. Mihalik and John G. Ratcliffe},
  journal= {arXiv preprint arXiv:0706.3911},
  year   = {2007}
}
R2 v1 2026-06-21T08:42:22.636Z