English

The Knight Move Conjecture is false

Geometric Topology 2018-10-09 v2 Quantum Algebra

Abstract

The Knight Move Conjecture claims that the Khovanov homology of any knot decomposes as direct sums of some "knight move" pairs and a single "pawn move" pair. This is true for instance whenever the Lee spectral sequence from Khovanov homology to Q^2 converges on the second page, as it does for all alternating knots and knots with unknotting number at most 2. We present a counterexample to the Knight Move Conjecture. For this knot, the Lee spectral sequence admits a nontrivial differential of bidegree (1,8).

Cite

@article{arxiv.1809.09769,
  title  = {The Knight Move Conjecture is false},
  author = {Ciprian Manolescu and Marco Marengon},
  journal= {arXiv preprint arXiv:1809.09769},
  year   = {2018}
}

Comments

4 pages; corrected a typo in Table 1

R2 v1 2026-06-23T04:18:29.801Z