Suppose that a knot is deformed into another knot by a ν-unknotting operation. Then we will show that the difference of their Nakanishi indices is less than or equal to three and that the difference of the minimum numbers of generators of the first homology groups of their double branched covers is less than or equal to two. We also give infinitely many examples of composite knots with ν-unknotting number one.
ASJC Scopus subject areas
- Geometry and Topology