FOX-RESIDUALLY NILPOTENT KNOTS AND VIRTUA L RIGIDITY OF HYPERBOLIC 3-MANIFOLDS

We introduce a class of knots and use it to prove a topological rigidi ty criterion for homotopy equivalences between 3-manifolds. As an appl ication, we give a new proof of Gabai's virtual rigidity theorem for h yperbolic 3-manifolds.