Clasp-pass moves and Kauffman polynomials of virtual knots
Abstract
Habiro showed that two knots K1K1 and K2K2 are related by a finite sequence of clasp-pass moves, if and only if they have the same value for Vassiliev invariants of type <3<3. Tsukamoto showed that, if two knots differ by a clasp-pass move then the values of the Vassiliev invariant V‴K(1) of degree 3 for the two knots differ by ±36 or 0, where VK(t) is the Jones polynomial of a knot K. If two virtual knots are related by clasp-pass moves, then they take the same value for all Vassiliev invariants of degree <3. We extend the Tsukamoto’s result to virtual knots by using a Vassiliev invariant v3 of degree 3, which is induced from the Kauffman polynomial. We also get a lower bound for the minimal number of clasp-pass moves needed to transform K1 to K2, if two virtual knots K1 and K2 can be related by a finite sequence of clasp-pass moves.