English

Acylindrical accessibility for groups acting on $\mathbf R$-trees

Group Theory 2007-05-23 v2 Geometric Topology

Abstract

We prove an acylindrical accessibility theorem for finitely generated groups acting on R\mathbf R-trees. Namely, we show that if GG is a freely indecomposable non-cyclic kk-generated group acting minimally and MM-acylindrically on an R\mathbf R-tree XX then for any ϵ>0\epsilon>0 there is a finite subtree YϵXY_{\epsilon}\subseteq X of measure at most 2M(k1)+ϵ2M(k-1)+\epsilon such that GYϵ=XGY_{\epsilon}=X. This generalizes theorems of Z.Sela and T.Delzant about actions on simplicial trees.

Keywords

Cite

@article{arxiv.math/0210308,
  title  = {Acylindrical accessibility for groups acting on $\mathbf R$-trees},
  author = {Ilya Kapovich and Richard Weidmann},
  journal= {arXiv preprint arXiv:math/0210308},
  year   = {2007}
}

Comments

Final revised version, to appear in Math. Z