English

On the intersection of tame subgroups in groups acting on trees

Group Theory 2018-01-11 v3

Abstract

Let GG be a group acting on a tree TT with finite edge stabilizers of bounded order. We provide, in some very interesting cases, upper bounds for the complexity of the intersection HKH\cap K of two tame subgroups HH and KK of GG in terms of the complexities of HH and KK. In particular, we obtain bounds for the Kurosh rank Kr(HK)Kr(H\cap K) of the intersection in terms of Kurosh ranks Kr(H)Kr(H) and Kr(K)Kr(K), in the case where HH and KK act freely on the edges of TT.

Keywords

Cite

@article{arxiv.1703.01117,
  title  = {On the intersection of tame subgroups in groups acting on trees},
  author = {Konstantinos Lentzos and Mihalis Sykiotis},
  journal= {arXiv preprint arXiv:1703.01117},
  year   = {2018}
}

Comments

15 pages. v2 updated to mention recent work by other researchers. Minor changes. v3 revised version following the referee's comments. Statement of Theorem 3.3 corrected