English

Simply-laced mixed-sign Coxeter groups, with an associate graph is a line or a simple cycle

Group Theory 2023-02-08 v1

Abstract

In 2011 Eriko Hironaka introduced an interesting generalization of Coxeter groups, motivated by studying certain mapping classes. The generalization is by labeling the vertices of a Coxeter graph either by +1 or by -1, and then generalizing the standard geometric representation of the associated Coxeter group by concerning the labels of the vertices. The group which Hironaka get by that generalization is called mixed-sign Coxeter group. In this paper we classify the simply-laced mixed-sign Coxeter groups where the associated graph is either a line or a simple cycle. We show that all the defining relations of the mixed-sign Coxeter groups with the mentioned associated graph (either a line or a simple cycle) are squares or cubes of a product of conjugates of two generators of the mixed-sign Coxeter group and are strongly connected to the labels of the vertices of the associated graph.

Keywords

Cite

@article{arxiv.2302.03403,
  title  = {Simply-laced mixed-sign Coxeter groups, with an associate graph is a line or a simple cycle},
  author = {Yiska Efrat Aharoni and Robert Shwartz},
  journal= {arXiv preprint arXiv:2302.03403},
  year   = {2023}
}
R2 v1 2026-06-28T08:33:59.825Z