A Remark About Actions of Lattices on Free Groups

Martin R. Bridson and Benson Farb

Preprint, March 1998 --- to appear in Topol. Appl.

Let $G$ be a semisimple Lie group with finite center and no compact factors. Assume that the real rank of $G$ is at least 2. Let $\G\subset G$ be a nonuniform, irreducible lattice. Then every homomorphism from $\Gamma$ to the outer automorphism group of a finitely generated free group has finite image.