Talk page

Title:
τ-invariants for knots in rational homology spheres

Speaker:
Katherine Raoux

Abstract:
Using the knot filtration on the Heegaard Floer chain complex, Ozsváth and Szabó defined an invariant of knots in the three sphere called τ(K), which they also showed is a lower bound for the 4-ball genus. Generalizing their construction, I will show that for a (not necessarily null-homologous) knot, K, in a rational homology sphere, Y, we may obtain a collection of τ-invariants, one for each spin-c structure. We also show that these invariants can be used to obtain a lower bound on the genus of a surface with boundary K properly embedded in a negative definite 4-manifold with boundary Y

Link:
http://scgp.stonybrook.edu/video_portal/video.php?id=3043

Workshop:
Simons- Program: Mathematics of gauge fields