{ "id": "1111.2499", "version": "v3", "published": "2011-11-10T15:21:30.000Z", "updated": "2018-09-14T10:31:31.000Z", "title": "Quasi-hyperbolic planes in relatively hyperbolic groups", "authors": [ "John M. Mackay", "Alessandro Sisto" ], "comment": "v1: 32 pages, 4 figures. v2: 38 pages, 4 figures. v3: 44 pages, 4 figures. An application (Theorem 1.2) is weakened as there was an error in its proof in section 7, all other changes minor, improved exposition", "categories": [ "math.GR", "math.GT", "math.MG" ], "abstract": "We show that any group that is hyperbolic relative to virtually nilpotent subgroups, and does not admit peripheral splittings, contains a quasi-isometrically embedded copy of the hyperbolic plane. In natural situations, the specific embeddings we find remain quasi-isometric embeddings when composed with the inclusion map from the Cayley graph to the coned-off graph, as well as when composed with the quotient map to \"almost every\" peripheral (Dehn) filling. We apply our theorem to study the same question for fundamental groups of 3-manifolds. The key idea is to study quantitative geometric properties of the boundaries of relatively hyperbolic groups, such as linear connectedness. In particular, we prove a new existence result for quasi-arcs that avoid obstacles.", "revisions": [ { "version": "v2", "updated": "2012-07-12T15:27:24.000Z", "abstract": "We show that any group that is hyperbolic relative to virtually nilpotent subgroups, and does not admit certain splittings, contains a quasi-isometrically embedded copy of the hyperbolic plane. The specific embeddings we find remain quasi-isometric embeddings when composed with the natural map from the Cayley graph to the coned-off graph, as well as when composed with the quotient map to \"almost every\" peripheral (Dehn) filling. We apply our theorem to study the same question for fundamental groups of 3-manifolds. The proofs of these theorems involve quantitative geometric properties of the boundaries of relatively hyperbolic groups, such as linear connectedness. In particular, we prove a new existence result for quasi-arcs that avoid obstacles.", "comment": "v1: 32 pages, 4 figures. v2: 38 pages, 4 figures. Improved exposition and minor corrections", "journal": null, "doi": null }, { "version": "v3", "updated": "2018-09-14T10:31:31.000Z" } ], "analyses": { "subjects": [ "20F65", "20F67", "51F99" ], "keywords": [ "relatively hyperbolic groups", "quasi-hyperbolic planes", "study quantitative geometric properties", "admit peripheral splittings", "remain quasi-isometric embeddings" ], "note": { "typesetting": "TeX", "pages": 32, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2011arXiv1111.2499M" } } }