Algebraic Geometry Seminar

Dynamical Degrees of Automorphisms of Algebraic Surfaces

Speaker: Igor Dolgachev, University of Michigan

Location: Warren Weaver Hall 201

Date: Tuesday, April 5, 2016, 3:30 p.m.


The dynamical degree of an automorphism of a nonsingular projective surface is the spectral radius of its action on the second cohomology group. When an automorphism is of hyperbolic type, it is a Salem number greater than 1. I will review some known results about these numbers and discuss their behavior in families of surface automorphisms, in particular in automorphisms of Enriques and K3 surfaces.