26 nov 2024 -- 14:30
Aula Riunioni - Dipartimento di Matematica, Pisa
Abstract.
We say that a link $L$ in $S^3$ is negative amphichiral if there exists an orientation-reversing diffeomorphism of $S^3$ that sends every component of $L$ to itself with the opposite orientation. If such a map can be chosen to be an involution, then the link is said to be strongly negative amphichiral. Kawauchi proved that every strongly negative amphichiral link is rationally slice, i.e. it bounds a disjoint collection of disks in a rational homology 4-ball. In this talk, we prove that every negative amphichiral link is rationally slice, extending the aforementioned work of Kawauchi. Our proof relies on a careful analysis of the JSJ decomposition of the link complement of negative amphichiral links. This is joint work in progress with Jaewon Lee (KAIST, Daejeon) and Oğuz Şavk (CNRS, Nantes).