Our goal is to find dynamic invariants that completely determine elements of the outer automorphism group of the free group of rank . To avoid finite order phenomena, we do this for forward rotationless elements. This is not a serious restriction. For example, there is depending only on such that, for all , is forward rotationless. An important part of our analysis is to show that rotationless elements are represented by particularly nice relative train track maps.
Cite this article
Mark Feighn, Michael Handel, The Recognition Theorem for Out(<var>F</var><sub><var>n</var></sub>). Groups Geom. Dyn. 5 (2011), no. 1, pp. 39–106DOI 10.4171/GGD/116