8 papers
Legendrian simple knots not detected by Khovanov homology
Chun-Sheng Hsueh, Marc Kegel, David Suchodoll +1
In this short note, we exhibit a Legendrian simple knot that is not detected by Khovanov homology. This disproves a conjecture of Chernov and Maguire.
The Conway knot has infinite concordance order
Chiara Donatone, Marc Kegel, Lukas Lewark +1
We examine how the Rasmussen invariant, satellite operations, and null-homologous twists can be used to establish infinite order of knots in the smooth concordance group. As an app…
Braid positive surgery diagrams
Marc Kegel, Paula Truöl
In this short note, we prove that every closed, oriented, connected 3-manifold arises as Dehn surgery along a braid positive link.
Transverse knots determined by their cyclic branched covers
Marc Kegel, Isacco Nonino
Harvey-Kawamuro-Plamenevskaya demonstrated the existence of (transversely) non-isotopic transverse knots such that for every their -fold cyclic branched covers are contact…
The Unsolvability of the Homeomorphism Problem
Stefan Friedl, Tobias Hirsch, Marc Kegel
In this short expository note, we give a detailed proof of Markov's theorem on the unsolvability of the homeomorphism problem and of the existence of unrecognizable manifolds in al…
Algorithms in 4-manifold topology
Stefan Bastl, Rhuaidi Burke, Rima Chatterjee +28
We show that there exists an algorithm that takes as input two closed, simply connected, topological 4-manifolds and decides whether or not these 4-manifolds are homeomorphic. In p…