Symplectic Geometry, Gauge Theory, and Low-Dimensional Topology Seminar
Monday March 31st, 2025
Time: 12:30 PM - 1:55 PM
Title: ASD Connections & Cosmetic Surgery
Speaker: Mike Miller Eismeier, University of Vermont
Location: Math P-131
Abstract:
The cosmetic surgery conjecture predicts that, given a knot K in a 3-manifold, the oriented diffeomorphism type of surgery on K determines the surgery slope (up to oriented diffeomorphism). For knots in the 3-sphere, a sequence of restrictions coming from Heegaard Floer homology implies that if the cosmetic surgery is false for K, then r-surgery on K is not oriented diffeomorphic to (-r)-surgery, for some r in {2, 1, 1/2, 1/3, …}, but Heegaard Floer homology techniques reach a limit here.

I will discuss how a quantitative enhancement of instanton homology rules out the cases r = 1/n, leaving only the possibility of 2-surgery. I will discuss limitations of this approach as well as possible future developments.