31st NRW Topology Meeting


+++   Bochum (GERMANY)   +++   Friday, May 10 and Saturday, May 11, 2019   +++


Stefan Behrens (Universität Bielefeld)

Froyshov-type invariants from a homotopical viewpoint

Froyshov's h-invariants are certain rational numbers that are associated to 3-dimensional spin^c manifolds that have the rational homology of the 3-sphere. They provide valuable information about intersection forms of 4-manifolds with boundary and the rational homology cobordism group. The h-invariants are usually extracted from the algebraic structure of monopole Floer homology. I will explain their relation to the primary obstructions in a series of extension problems that naturally arise in Manolescu's stable homotopy approach to Seiberg-Witten theory on 3-manifolds. The higher obstructions lead to refined, potentially stronger Froyshov-type invariants. This is work in progress with Tyrone Cutler.

Organizers: Gerd Laures, Viktoriya Ozornova and Björn Schuster