English

Thickness of $\mathsf{Out}(A_1*...*A_n)$

Group Theory 2018-11-06 v2

Abstract

In this paper we have examined hyperbolicity and relative hyperbolicity of Γn:=Out(Gn)\Gamma_n := \mathsf{Out}(G_n) , where Gn=A1...AnG_n = A_1*...*A_n, is a finite free product and each AiA_i is a finite group. We have used the Out(Gn)\mathsf{Out}(G_n) action on the Guirardel-Levitt deformation space, to find a virtual generating set and prove quasi isometric embedding of a large class of subgroups. We have used ideas from works of Mosher-Handel and Alibegovi\'c to prove non-distortion. We have used these subgroups to prove that Γn\Gamma_n is thick for higher complexities. Thickness was developed by Behrstock-Dru\c{t}u-Mosher and thickness implies that the groups are non-relatively hyperbolic.

Keywords

Cite

@article{arxiv.1811.00435,
  title  = {Thickness of $\mathsf{Out}(A_1*...*A_n)$},
  author = {Saikat Das},
  journal= {arXiv preprint arXiv:1811.00435},
  year   = {2018}
}