{ "id": "1312.0278", "version": "v2", "published": "2013-12-01T21:49:43.000Z", "updated": "2014-12-17T18:11:21.000Z", "title": "Commability of groups quasi-isometric to trees", "authors": [ "Mathieu Carette" ], "comment": "22 pages. Final version, incorporating referee's comments. To appear in Annales de L'Institut Fourier", "categories": [ "math.GR", "math.MG" ], "abstract": "Commability is the finest equivalence relation between locally compact groups such that $G$ and $H$ are equivalent whenever there is a continuous proper homomorphism $G \\to H$ with cocompact image. Answering a question of Cornulier, we show that all non-elementary locally compact groups acting geometrically on locally finite simplicial trees are commable, thereby strengthening previous forms of quasi-isometric rigidity for trees. We further show that 6 homomorphisms always suffice, and provide the first example of a pair of locally compact groups which are commable but without commation consisting of less than 6 homomorphisms. Our strong quasi-isometric rigidity also applies to products of symmetric spaces and Euclidean buildings, possibly with some factors being trees.", "revisions": [ { "version": "v1", "updated": "2013-12-01T21:49:43.000Z", "comment": "22 pages", "journal": null, "doi": null }, { "version": "v2", "updated": "2014-12-17T18:11:21.000Z" } ], "analyses": { "subjects": [ "22D05", "20F65", "20E08", "20E42" ], "keywords": [ "groups quasi-isometric", "commability", "locally compact groups acting", "non-elementary locally compact groups" ], "note": { "typesetting": "TeX", "pages": 22, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1312.0278C" } } }