Virtual link and knot invariants from non-abelian Yang-Baxter 2-cocycle pairs

Abstract

For a given $(X,S,\beta )$, where $S,\beta :X\times X\to X\times X$ are set theoretical solutions of Yang-Baxter equation with a compatibility condition, we define an invariant for virtual (or classical) knots/links using non commutative 2-cocycles pairs $(f,g)$ that generalizes the one defined in [FG2]. We also define, a group $U_{nc}^{fg}=U_{nc}^{fg}(X,S,\beta )$ and functions ${\pi }_f,{\pi }_g:X\times X\to U_{nc}^{fg}(X)$ governing all 2-cocycles in $X$. We exhibit examples of computations achieved using GAP.

22 pages, 17 figures, come typos corrected