Title:	Witt vectors, Lambda-rings, and absolute algebraic geometry
Speaker:	Jim Borger (ANU)
Abstract:	I will explain how the closely related concepts of Witt vector and Lambda-ring give rise to a kind of algebraic geometry that is, in a precise sense, over a deeper base than the ring of integers, the usual base in arithmetic algebraic geometry. I will also say something about how this related to other issues in arithmetic algebraic geometry.