English

The action of a Coxeter element on an affine root system

Combinatorics 2026-05-13 v3

Abstract

The characterization of orbits of roots under the action of a Coxeter element is a fundamental tool in the study of finite root systems and their reflection groups. This paper develops the analogous tool in the affine setting, adding detail and uniformity to a result of Dlab and Ringel.

Keywords

Cite

@article{arxiv.1808.05090,
  title  = {The action of a Coxeter element on an affine root system},
  author = {Nathan Reading and Salvatore Stella},
  journal= {arXiv preprint arXiv:1808.05090},
  year   = {2026}
}

Comments

Version 1: This is a revised version of the first 1/3 of arXiv:1707.00340. (That paper will also be replaced by a new version, deleting the first 1/3 and with other major revisions). Version 2: Minor corrections to front and back matter. Version 3: Added mention of Dlab and Ringel, who proved essentially the same result in 1976 by a non-uniform argument