Special alternating links of minimal unlinking number
Geometric Topology
2026-03-25 v2
Abstract
For any link in the 3-sphere, there is a natural lower bound for the unlinking number in terms of the classical signature. We prove that if this lower bound is sharp for a special alternating link , then the unlinking number of is necessarily realized by crossing changes in any alternating diagram for . As an application, we compute new values of the unknotting numbers for some special alternating knots with crossing number 11 and 12.
Cite
@article{arxiv.2603.10732,
title = {Special alternating links of minimal unlinking number},
author = {Duncan McCoy and JungHwan Park},
journal= {arXiv preprint arXiv:2603.10732},
year = {2026}
}
Comments
10 pages, 4 figures. Changes to introduction including addition of a result on additivity of the unknotting number