Mathematics Colloquia and Seminars
Concordance in homology cobordismsGeometry/Topology
|Speaker:||Tye Lidman, North Carolina State University|
|Start time:||Thu, Oct 5 2017, 3:10PM|
Not all knots bound a disk in the three-sphere, but they do always bound a PL disk in the four-ball. It turns out that this fails for knots in arbitrary homology spheres. We study a group that measures this failure and show that it is infinitely-generated. This is joint work with Jen Hom and Adam Levine.