{ "id": "1905.00738", "version": "v1", "published": "2019-05-01T07:41:15.000Z", "updated": "2019-05-01T07:41:15.000Z", "title": "A note on torsion subgroups of groups acting on finite-dimensional CAT(0) cube complexes", "authors": [ "Anthony Genevois" ], "comment": "15 pages, 3 figures. Comments are welcome. arXiv admin note: text overlap with arXiv:1902.04883", "categories": [ "math.GR" ], "abstract": "In this article, we state and prove a general criterion which prevents some groups from acting properly on finite-dimensional CAT(0) cube complexes. As an application, we show that, for every non-trivial finite group $F$, the lamplighter group $F \\wr \\mathbb{F}_2$ over a free group does not act properly on a finite-dimensional CAT(0) cube complex (although it acts properly on a infinite-dimensional CAT(0) cube complex). We also deduce from this general criterion that, roughly speaking, given a group $G$ acting on a CAT(0) cube complex of finite dimension and an infinite torsion subgroup $L \\leq G$, either the normaliser $N_G(L)$ is close to be free abelian or, for every $k \\geq 1$, $N_G(L)$ contains a non-abelian free subgroup commuting with a subgroup of $L$ of size $\\geq k$.", "revisions": [ { "version": "v1", "updated": "2019-05-01T07:41:15.000Z" } ], "analyses": { "subjects": [ "20F65", "20F67" ], "keywords": [ "cube complex", "groups acting", "general criterion", "non-trivial finite group", "infinite torsion subgroup" ], "note": { "typesetting": "TeX", "pages": 15, "language": "en", "license": "arXiv", "status": "editable" } } }