Thu, April 27, 2017
1:50 pm - 2:45 pm
Cockins Hall 240
Title: The congruence subgroup problem for a family of branch groups
Speaker: Rachel Skipper (Binghamton University)
Abstract: A group, G, acting on a regular rooted tree has the congruence subgroup property if every subgroup of finite index contains the stabilizer of a level of the tree. When the subgroup structure of G resembles that of the full automorphism group of the tree, additional tools are available for determining if G has the congruence subgroup property.
In this talk, we look at the Hanoi towers group which has fails to have the congruence subgroup property in a particular way. Then we will generalize this construction to a new family of groups and discuss the congruence subgroup property for them.