Copies of a one-ended group in a Mapping Class Group
arXiv:0709.0797 · doi:10.4171/GGD/61
Abstract
We establish that, given a compact orientable surface, and a finitely presented one-ended group, the set of copies of in the mapping class group consisting of only pseudo-anosov elements except identity, is finite up to conjugacy. This relies on a result of Bowditch on the same problem for images of surfaces groups. He asked us whether we could reduce the case of one-ended groups to his result ; this is a positive answer. Our work involves analogues of Rips and Sela canonical cylinders in curve complexes, and the argument of Delzant to bound the number of images of a one-ended group in a hyperbolic group.
16 pages, 3 figures, revised