Breaking the classification barrier
Speaker:
George Elliott, University of Toronto
Date and Time:
Thursday, September 21, 2023 - 11:20am to 12:10pm
Location:
Fields Institute, Room 230
Abstract:
So far only simple C*-algebras with radius of comparison zero have been classified. The stable rank one simple C*-algebras constructed by Villadsen can have any radius of comparison. If the seed space on which the Villadsen construction is based is an arbitrary finite-dimensional cube, and the algebra has non-zero radius of comparison, then the algebra is determined (independently of all choices in the construction) by its radius of comparison (together with its K$_0$-group, which is a subgroup of the rational numbers containing the number 1, representing the class of the unit). In particular the trace simplex is determined---in fact it is always the same. This is joint work with Zhuang Niu and Chun Guang Li.