Tuesday Seminar on Topology

Seminar information archive ~09/27Next seminarFuture seminars 09/28~

Date, time & place Tuesday 17:00 - 18:30 056Room #056 (Graduate School of Math. Sci. Bldg.)
Organizer(s) KAWAZUMI Nariya, KITAYAMA Takahiro, SAKASAI Takuya


16:30-18:00   Room #056 (Graduate School of Math. Sci. Bldg.)
五味 清紀 (東京大学大学院数理科学研究科)
Realization of twisted $K$-theory and
finite-dimensional approximation of Fredholm operators
[ Abstract ]
A problem in twisted $K$-theory is to realize twisted $K$-groups generally by means of finite-dimensional geometric objects, like vector bundles. I would like to talk about an approach toward the problem by means of Mikio Furuta's generalized vector bundles. By using a twisted version of the generalized vector bundle and a finite-dimensional approximation of Fredholm operators, I construct a group into which there exists a natural injection from the twisted $K$-group twisted by any third integral cohomology class.