Topology and Geometry Seminar

Location: AH 347

Speaker: Yang Hu, University of Regina

Title: Orientation orders and chromatic defects

Abstract:  

A ring spectrum (a.k.a. a multiplicative cohomology theory) \(E\) is complex-orientable if every complex vector bundle admits a Thom class in \(E\). While many familiar spectra are complex-orientable, notable examples fail to be so — such as real K-theory and topological modular forms. To measure this failure precisely, two competing ideas have been proposed: the complex orientation order and the chromatic defect. A natural question is whether the two notions are related. In this talk, we will present examples that suggest a negative answer. This is joint work with Prasit Bhattacharya and Christian Carrick.