Mathematics Colloquia and Seminars

Return to Colloquia & Seminar listing

Controlled Mather Thurston theorems


Speaker: Mike Freedman, Microsoft Station Q
Location: Zoom
Start time: Tue, Mar 2 2021, 1:10PM

In the work of Milnor Wood and in the Mather Thurston theorem, we encounter flat connections in surprising places. The surprise is comes from the close encounter with obstructions ( that would prevent theses connections) from Godbillion-Vey and Chern-Weil. The escape from contradiction is that the constructions have larger structure groups than needed to define the obstructions. I will describe some techniques for constructing flat connections with additional control, and briefly touch on the physics motivation for achieving this control.