The special rank of virtual knot groups
Abstract
In this paper we introduce the special rank for virtual knots and some properties of this number are studied. Although we do not know if it can be considered as a nontrivial extension of the meridional rank given by [H. U. Boden and A. I. Gaudreau, Bridge number for virtual and welded knots, J. Knot Theory Ramifications24 (2015), Article ID: 1550008] and by [M. Boileau and B. Zimmermann, The ππ-orbifold group of a link, Math. Z.200 (1989) 187–208], we prove that classical knots with special rank 22 are 22-bridge knots. Therefore, a modified version of the so called Cappell and Shaneson conjecture could be considered.