# Witt vectors, Lambda-rings, and absolute algebraic geometry

Algebra/Geometry/Topology Seminar

#### by Jim Borger

Institution: ANU
Date: Fri 6th February 2009
Time: 2:30 PM
Location: JH Michell Theatre

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.