Speaker: Ikhan Choi (University of Tokyo)

Title: Haagerup's problems on normal weights

Time/Date: 4:45-6:15pm, May 13 (Tue), 2025

Room: 126 Math Sci Building (It will be also online. The Zoom link is the same as before. If you don't have one, please ask Kawahigashi.)

Abstract: We will introduce three open problems related to normal weights posed by Haagerup fifty years ago in his master's thesis. Among these, we especially discuss a solution to the last problem and its meaning. This will provide a complete set of the positive Hahn-Banach separation theorems on operator algebras and shed light on why the weak* topologies on the duals of C*-algebras are relatively difficult to work with. (arXiv:2501.16832.)