Applications of Donaldson's Diagonalization Theorem

Geometry Topology Working Seminar
Friday, October 15, 2021 - 2:00pm for 1 hour (actually 50 minutes)
Skiles 006
Jonathan Simone – Georgia Tech –
Jonathan Simone

Please Note: Donaldson’s Diagonalization Theorem has been used extensively over the past 15 years as an obstructive tool. For example, it has been used to obstruct: rational homology 3-spheres from bounding rational homology 4-balls; knots from being (smoothly) slice; and knots from bounding (smooth) Mobius bands in the 4-ball. In this multi-part series, we will see how this obstruction works, while getting into the weeds with concrete calculations that are usually swept under the rug during research talks.