| Résume | The centralizer Z(f) of a diffeomorphism f: M--> M of a closed manifold M is the group of all diffeomorphisms commuting with f; it is the collection of dynamical symmetries of f. The centralizer of f always contains the group <f> generated by f as a normal subgroup, and conjecturally the two typically coincide (that is, ``the generic diffeomorphism has only trivial symmetries''). In this talk, I will describe some results and conjectures in a project with Danijela Damjanovic, Chengyang Wu and Disheng Xu that addresses the question: what happens when Z(f) is bigger than <f>? |
