A short proof of Handel and Mosher's alternative for subgroups of Out(FN)(F_N)

  • Camille Horbez

    Université Paris-Sud, Orsay, France

Abstract

We give a short proof of a theorem of Handel and Mosher [21] stating that any finitely generated subgroup of Out(FN)(F_N) either contains a fully irreducible automorphism, or virtually fixes the conjugacy class of a proper free factor of FNF_N, and we extend their result to non finitely generated subgroups of Out(FN)(F_N).

Cite this article

Camille Horbez, A short proof of Handel and Mosher's alternative for subgroups of Out(FN)(F_N). Groups Geom. Dyn. 10 (2016), no. 2, pp. 709–721

DOI 10.4171/GGD/361