skip to main content
Caltech

Noncommutative Geometry Seminar

Monday, February 8, 2016
4:00pm to 5:00pm
Add to Cal
II_1 Factors with Non-isomorphic Ultrapowers
Adrian Ioana, Professor, Mathematics, UCSD,

A II_1 factor is an infinite dimensional von Neumann algebra which has infinite center and admits a trace. As I will recall, examples of II_1 factors arise naturally from countable groups (with infinite conjugacy classes), and their measure preserving actions on probability spaces. I will present a recent result showing the existence of uncountably many separable II_1 factors whose ultrapowers, with respect to arbitrary ultrafilters, are pairwise non-isomorphic. More precisely, the families of non-isomorphic II_1 factors originally introduced by McDuff (1969) are such examples. This is joint work with Remi Boutonnet and Ionut Chifan.

For more information, please contact Farzad Fathizadeh by email at [email protected] or visit http://www.math.caltech.edu/~ncg/.