Mon, 01 Jun 2026
13:30
13:30
C1
Classification of ultrapowers of full II1 factors
Greg Patchell
((Mathematical Institute University of Oxford))
Abstract
Much recent research has gone into understanding the first order theory of II1 factors. Very recently, Peterson released a preprint which develops deformation rigidity in the ultrapower setting. His techniques give many explicit examples of non-isomorphic ultrapowers for natural families of II1 factors. In this talk, I will introduce some of Peterson's techniques and results, including an analogue of amenability in the ultrapower setting and the interplay between property T and malleable deformations.