A class of index polynomial invariants for virtual knots using flat virtual knots invariants
Abstract
In this paper, a class of indices is constructed using a polynomial invariant g for flat virtual knots. For any integer n not less than 2, the classical crossings of an oriented virtual knot diagram are classified into two types according to whether the intersection index of the classical crossings can be divided by n. We assign an index to each classical crossing whose intersection index is not divisible by n, the index is related to the flat virtual knot diagram corresponding to the virtual knot diagram obtained by applying 0-smoothing at that classical crossing. We construct a class of index polynomials by using these indices and prove that they are invariants of virtual knots, and also discuss some of their properties.