The Lee spectral sequence, unknotting number, and the Knight Move Conjecture

摘要

We show that the page at which the Lee spectral sequence collapses gives a bound on the unknotting number, u(K). In particular, for knots with u(K) = 2, we show that the Lee spectral sequence must collapse at the E-2 page. An immediate corollary is that the Knight Move Conjecture is true when u(K) = 2. (C) 2018 Elsevier B.V. All rights reserved.