Hello everyone,

Today in topology seminar we have Jennifer Hom speaking at 4pm in MSCS 514. We will resume seminar at the normal time Tuesdays at 3:30 in the coming weeks. If you would like to sign up for a slot let me know.

PL-surfaces in homology 4-balls Jennifer Hom, Georgia Institute of Technology

Abstract: We consider manifold-knot pairs (Y, K) where Y is a homology 3-sphere that bounds a homology 4-ball. Adam Levine proved that there exist pairs (Y, K) such that K does not bound a PL-disk in any bounding homology ball. We show that the minimum genus of a PL surface S in any bounding homology ball can be arbitrarily large. The proof relies on Heegaard Floer homology. This is joint work with Matthew Stoffregen and Hugo Zhou.

______________________

Neil R. Hoffman Assistant Professor Department of Mathematics 523 Math Science Building Oklahoma State University Stillwater, OK 74078-1058 405-744-7791 http://math.okstate.edu/people/nhoffman