{ "id": "1908.09046", "version": "v1", "published": "2019-08-23T22:37:41.000Z", "updated": "2019-08-23T22:37:41.000Z", "title": "A study of subgroups of right-angled Coxeter groups via Stallings-like techniques", "authors": [ "Pallavi Dani", "Ivan Levcovitz" ], "comment": "52 pages, 4 figures", "categories": [ "math.GT", "math.GR" ], "abstract": "We associate a cube complex to any given finitely generated subgroup of a right-angled Coxeter group, called the completion of the subgroup. A completion characterizes many properties of the subgroup such as whether it is quasiconvex, normal, finite-index or torsion-free. We use completions to show that reflection subgroups are quasiconvex, as are one-ended Coxeter subgroups of a 2-dimensional right-angled Coxeter group. We provide an algorithm that determines whether a given one-ended, 2-dimensional right-angled Coxeter group is isomorphic to some finite-index subgroup of another given right-angled Coxeter group. In addition, we answer several algorithmic questions regarding quasiconvex subgroups. Finally, we give a new proof of Haglund's result that quasiconvex subgroups of right-angled Coxeter groups are separable.", "revisions": [ { "version": "v1", "updated": "2019-08-23T22:37:41.000Z" } ], "analyses": { "subjects": [ "20F65", "20F55" ], "keywords": [ "right-angled coxeter group", "stallings-like techniques", "algorithmic questions regarding quasiconvex subgroups", "completion", "haglunds result" ], "note": { "typesetting": "TeX", "pages": 52, "language": "en", "license": "arXiv", "status": "editable" } } }