URegina Topology and Geometry Seminar: Yang Hu

Abstract: We will complete the story from last time: the Chern character does not map the K-theoretic Thom class directly to the HZ-theoretic one. Figuring out the error term – the Todd class – will lead us to the Grothendieck-Riemann-Roch theorem. We will see that the 4-sphere cannot be almost complex, as a cute little application of GRR. The Todd genus then immediately invites us to a range of further topics, and we will explore a few exciting ones.

Advertisement: Bernoulli numbers will actually appear multiple times in this talk.