Representations of knot groups and Vassiliev invariants

Abstract

We show that the number of homomorphisms from a knot group to a finite group $G$ cannot be a Vassiliev invariant, unless it is constant on the set of $(2,2p+1)$ torus knots. In several cases, such as when $G$ is a dihedral or symmetric group, this implies that the number of homomorphisms is not a Vassiliev invariant.