REAL-SPACE RENORMALIZATION-GROUP METHODS AND QUANTUM GROUPS

We apply real space renormalization group (RG) methods to study two qu antum group invariant Hamiltonians, that of the XXZ model and the Isin g model in a transverse field (ITF) defined in an open chain with appr opriate boundary terms. The quantum group symmetry is preserved under the RG transformation except for the appearance of a quantum group ano malous term which vanishes in the classical case. We obtain correctly the line of critical XXZ models. In the ITF model the RG flow coincide s with the tensor product decomposition of cyclic irreducible represen tations of SUq(2) with q(4) = 1.