Unknotting with a single twist
Samantha Allen
Dartmouth College, Hanover, USACharles Livingston
Indiana University, Bloomington, USA
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Abstract
Given a knot , is it possible to unknot it by performing a single twist, and if so, what are the possible linking numbers of such a twist? We develop obstructions to unknotting using a twist of a specified linking number. The obstructions we describe are built using classical knot invariants, Casson–Gordon invariants, and Heegaard Floer theory.
Cite this article
Samantha Allen, Charles Livingston, Unknotting with a single twist. Enseign. Math. 66 (2020), no. 3/4, pp. 541–589
DOI 10.4171/LEM/66-3/4-10