Some isomorphism results for Thompson like groups $V_n(G)$
Abstract
We consider a class of groups which are supergroups of the Higman-Thompson groups . These groups fit in a framework of Elizabeth Scott for generating infinite virtually simple groups, and the groups we study in particular are initially introduced by Farley and Hughes. The group is the result one obtains by taking the generators and adding a tree automorphism for each generator of a subgroup of the symmetric group on letters, where the new generators each permute the child leaves of a specific vertex of the infinite rooted -ary tree according to the permutation they represent, and then they iterate this permutation again at each vertex which is a descendent of . Farley and Hughes show that is not isomorphic to when fails to act freely on the points , and expect further non-isomorphism results in the other cases. We show the perhaps surprising result that if does act freely, then . We also generalise these results and produce some examples of even more isomorphisms amongst groups in the family . Essential tools in the above work are a study of the dynamics of the action of elements of on Cantor space, Rubin's Theorem, and transducers from Grigorchuk, Nekrashevych, and Suschanski\u{i}'s rational group on the -ary alphabet.
Cite
@article{arxiv.1410.8726,
title = {Some isomorphism results for Thompson like groups $V_n(G)$},
author = {Collin Bleak and Casey Donoven and Julius Jonušas},
journal= {arXiv preprint arXiv:1410.8726},
year = {2014}
}
Comments
10 pages and 3 figures; updated to clean text