Zhiyun Cheng (Beijing Normal University)
As an extension of classical knot theory, virtual knot theory studies the embeddings of one sphere in thickened surfaces up to stable equivalence. Roughly speaking, there are two kinds of virtual knot invariants, the first kind comes from knot invariants of classical knots but the second kind usually vanishes on classical knots. Most of the second kind of virtual knot invariants are defined by using the chord parity or chord index. In this talk, I will report some recent progress on virtual knot invariants derived from various chord indices.