Quaternionic Invariants of Virtual Knots and Links
arXiv:math/0610484
Abstract
In this paper we define and give examples of a family of polynomial invariants of virtual knots and links. They arise by considering certain 22 matrices with entries in a possibly non-commutative ring, for example the quaternions. These polynomials are sufficiently powerful to distinguish the Kishino knot from any classical knot, including the unknot.
21 pages, 13 figures, accepted by JKTR