Finite-index accessibility of groups

Abstract

We prove an accessibility theorem for finite-index splittings of groups. Given a finitely presented group G there is a number n(G) such that, for every reduced locally finite G-tree T with finitely generated stabilizers, T/G has at most n(G) vertices and edges. We also show that deformation spaces of locally finite trees (with finitely generated stabilizers) are maximal in the partial ordering of domination of G-trees.