Published on *Max Planck Institute for Mathematics* (http://www.mpim-bonn.mpg.de)

Posted in

- Talk [1]

Speaker:

Alexandra Kjuchukova
Affiliation:

University of Wisconsin-Madison/MPIM
Date:

Tue, 2019-09-17 10:30 - 10:55 Let $K$ be a knot with the property that $\pi_1(S^3\backslash K)$ surjects onto a dihedral group. I will define a ribbon obstruction for $K$, given a cover of $S^4$ branched along a surface embedded smoothly in $S^4$ except for one cone singularity, the cone on $K$. I will give examples of knots whose non-ribbonness can be detected by this method, and I will state a few results in the subject. Based on joint works with Cahn, Geske, Orr, Shaneson.

**Links:**

[1] http://www.mpim-bonn.mpg.de/taxonomy/term/39

[2] http://www.mpim-bonn.mpg.de/node/3444

[3] http://www.mpim-bonn.mpg.de/node/9096