On knots having zero negative unknotting number
arXiv:1604.01868
Abstract
A knot in the 3-sphere is said to have zero negative unknotting number if it can be transformed into the unknot by performing only positive crossing changes. In this paper, we provide an obstruction for a knot to having zero negative unknotting number, and discuss its application to two classes of knots.
14 pages, 5 figures. This paper was published two years ago