English

Vertex finiteness for splittings of relatively hyperbolic groups

Group Theory 2019-06-07 v2 Geometric Topology

Abstract

Consider a group G and a family A\mathcal{A} of subgroups of G. We say that vertex finiteness holds for splittings of G over A\mathcal{A} if, up to isomorphism, there are only finitely many possibilities for vertex stabilizers of minimal G-trees with edge stabilizers in A\mathcal{A}. We show vertex finiteness when G is a toral relatively hyperbolic group and A\mathcal{A} is the family of abelian subgroups. We also show vertex finiteness when G is hyperbolic relative to virtually polycyclic subgroups and A\mathcal{A} is the family of virtually cyclic subgroups; if moreover G is one-ended, there are only finitely many minimal G-trees with virtually cyclic edge stabilizers, up to automorphisms of G.

Keywords

Cite

@article{arxiv.1311.2835,
  title  = {Vertex finiteness for splittings of relatively hyperbolic groups},
  author = {Vincent Guirardel and Gilbert Levitt},
  journal= {arXiv preprint arXiv:1311.2835},
  year   = {2019}
}

Comments

Minor modifications following referee's comments. To appear in Israel Journal of Mathematics