2013/12/09 by Banks, Christopher C., Elder, Murray, Willis, George A.
#20E08 #20E32 #22D05 #22F50 #FOS: Mathematics #Group Theory (math.GR)
paper · doi:10.48550/arxiv.1312.2311
We introduce the notion of the k-closure of a group of automorphisms of a locally finite tree, and give several examples of the construction. We show that the k-closure satisfies a new property of automorphism groups of trees that generalises Tits' Property P. We prove that, apart from some degenerate cases, any non-discrete group acting on a tree with this property contains an abstractly simple subgroup.