{ "id": "math/0505572", "version": "v3", "published": "2005-05-26T15:15:45.000Z", "updated": "2005-06-10T20:28:30.000Z", "title": "Amenability of Universal 2-Grigorchuk group", "authors": [ "Roman Muchnik" ], "comment": "10 pages", "categories": [ "math.GR", "math.CO" ], "abstract": "We consider the universal Grigorchuk 2-group, i.e., the group such that every Grigorchuk 2-group is a quotient. We show that this group has a nice universal representation in the group of all functions f:{0,1,2}^N --> Aut(T_2), where T_2 is a group of automorphism of the binary tree. Finally, we prove that this universal Grigorchuk 2-group is amenable. The proof is an application of the ``Munchhausen trick'' developed by V. Kaimanovich.", "revisions": [ { "version": "v3", "updated": "2005-06-10T20:28:30.000Z" } ], "analyses": { "keywords": [ "amenability", "universal grigorchuk", "nice universal representation", "binary tree", "munchhausen trick" ], "note": { "typesetting": "TeX", "pages": 10, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2005math......5572M" } } }