On the Kronheimer-Mrowka concordance invariant

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Sherry Gong, University of California, Los Angeles

Zoom link:

https://princeton.zoom.us/j/453512481

We will talk about Kronheimer and Mrowka’s knot concordance invariant, $s^\sharp$. We compute the invariant for various knots. Our computations reveal some unexpected phenomena, including that $s^\sharp$ differs from Rasmussen's invariant $s$, and that it is not additive under connected sums. We also generalize the definition of $s^\sharp$ to links by giving a new characterization of the invariant in terms of immersed cobordisms.