Röver's Simple Group is of Type
arXiv:1312.2282
Abstract
We prove that Claas Röver's Thompson-Grigorchuk simple group has type . The proof involves constructing two complexes on which acts: a simplicial complex analogous to the Stein complex for , and a polysimiplical complex analogous to the Farley complex for . We then analyze the descending links of the polysimplicial complex, using a theorem of Belk and Forrest to prove increasing connectivity.
18 pages, no figures; improved exposition and added details