{ "id": "2009.05450", "version": "v1", "published": "2020-09-11T13:59:11.000Z", "updated": "2020-09-11T13:59:11.000Z", "title": "A Description of Aut(dVn) and Out(dVn) Using Transducers", "authors": [ "Luke Elliott" ], "comment": "17 Pages, 4 figures", "categories": [ "math.GR" ], "abstract": "The groups $dV_n$ are an infinite family of groups, first introduced by C. Mart\\'inez-P\\'erez, F. Matucci and B. E. A. Nucinkis, which includes both the Higman-Thompson groups $V_n(=1V_n)$ and the Brin-Thompson groups $nV(=nV_2)$. A description of the groups $\\operatorname{Aut}(G_{n, r})$ (including the groups $G_{n,1}=V_n$) has previously been given by C. Bleak, P. Cameron, Y. Maissel, A. Navas, and F. Olukoya. Their description uses the transducer representations of homeomorphisms of Cantor space introduced a paper of R. I. Grigorchuk, V. V. Nekrashevich, and V. I. Sushchanskii, together with a theorem of M. Rubin. We generalise the transducers of the latter paper and make use of these transducers to give a description of $\\operatorname{Aut}(dV_n)$ which extends the description of $\\operatorname{Aut}(1V_n)$ given in the former paper. We make use of this description to show that $\\operatorname{Out}(dV_2) \\cong \\operatorname{Out}(V_2)\\wr S_d$, and more generally give a natural embedding of $\\operatorname{Out}(dV_n)$ into $\\operatorname{Out}(G_{n, n-1})\\wr S_d$.", "revisions": [ { "version": "v1", "updated": "2020-09-11T13:59:11.000Z" } ], "analyses": { "subjects": [ "20B27", "20E36", "37B05" ], "keywords": [ "description", "higman-thompson groups", "brin-thompson groups", "transducer representations", "cantor space" ], "note": { "typesetting": "TeX", "pages": 17, "language": "en", "license": "arXiv", "status": "editable" } } }