{ "id": "1712.06727", "version": "v1", "published": "2017-12-19T00:38:18.000Z", "updated": "2017-12-19T00:38:18.000Z", "title": "On parabolic subgroups of Artin-Tits groups of spherical type", "authors": [ "María Cumplido", "Volker Gebhardt", "Juan González-Meneses", "Bert Wiest" ], "comment": "35 pages, 8 figures", "categories": [ "math.GR", "math.GT" ], "abstract": "We show that, in an Artin-Tits group of spherical type, the intersection of two parabolic subgroups is a parabolic subgroup. Moreover, we show that the set of parabolic subgroups forms a lattice with respect to inclusion. This extends to all Artin-Tits groups of spherical type a result that was previously known for braid groups. To obtain the above results, we show that every element in an Artin-Tits group of spherical type admits a unique minimal parabolic subgroup containing it. Also, the subgroup associated to an element coincides with the subgroup associated to any of its powers or roots. As a consequence, if an element belongs to a parabolic subgroup, all its roots belong to the same parabolic subgroup.", "revisions": [ { "version": "v1", "updated": "2017-12-19T00:38:18.000Z" } ], "analyses": { "subjects": [ "20F36", "20F65" ], "keywords": [ "artin-tits group", "spherical type", "parabolic subgroups forms", "unique minimal parabolic subgroup containing", "braid groups" ], "note": { "typesetting": "TeX", "pages": 35, "language": "en", "license": "arXiv", "status": "editable" } } }