Some questions and theorems about closed 3 manifolds embedded in S^4

Prof. Freedman who will talk about:

Title: Some questions and theorems about closed 3 manifolds embedded in S^4

Abstract: Much is unknown about smooth embeddings of 3-manifolds in S^4; the Schoenflies problem (Is there only one smoothly embedded 3-sphere in S^4 up to isotopy?) is the best-known example. There has long been a hope that 3-manifold reasoning applied to level-sets will be helpful. I’ll mention some successes and failures of this method and revisit a classical theorem of Hantzsche in this light. (Hantzsche: If a 3-manifold embeds in S^4 its linking form is hyperbolic.)

And Prof. Slava Krushkal (University of Virginia) who will talk about:

Title: A higher order torsion linking form for 3-manifolds

Abstract: This talk is based on a joint work with Mike Freedman defining a triple linking form for rational homology spheres, assuming that the classical torsion linking pairing of three classes pairwise vanishes. I will discuss its vanishing for 3-manifolds in S^4, and its relation to the Matsumoto triple intersection form on 4-manifolds.

The zoom link and password are:

Zoom link: https://harvard.zoom.us/j/99041531151
Password: cmsa