Retracts of vertex sets of trees and the almost stability theorem
Retracts of vertex sets of trees and the almost stability theorem
Let G be a group, let T be an (oriented) G-tree with finite edge stabilizers, and let VT denote the vertex set of T. We show that, for each G-retract V' of the G-set VT, there exists a G-tree whose edge stabilizers are finite and whose vertex set is V'. …