UNIVERSALITY AND THE RENORMALIZABILITY OF ROTATIONALLY INVARIANT KONDO HAMILTONIANS

Wilson's numerical technique (1974, 1975) has been used to study the effects of including an extra potential term in the Kondo Hamiltonian and the effects of using and s-d exchange matrix which lacks particle-hole symmetry. It is found that these generalised Kondo Hamiltonians have universal properties. They can all be mapped into a canonical form for the Kondo Hamiltonian, one which possesses a particle-hole symmetry, provided that the operators in this canonical form now create and destroy one-electron basis states that have a phase-shift with respect to the original ones. The underlying physical reason for this universality is that the field theory belonging to the Kondo Hamiltonian is renormalisable.