The Subadditive Ergodic Theorem and generic stretching factors for free group automorphisms

Vadim Kaimanovich, Ilya Kapovich, Paul Schupp

Given a free group $F_k$ of rank $k\ge 2$ with a fixed set of free generators we associate to any homomorphism $\varphi$ from $F_k$ to a group $G$ with a left-invariant semi-norm a gener…