Renormalization of lattice gauge theories with massless Ginsparg-Wilson fermions

Using functional techniques, we prove, to all orders of perturbation theory , that lattice vector gauge theories with Ginsparg-Wilson fermions are reno rmalizable. For two or mon massless fermions, they satisfy a flavour mixing axial vector Ward identity. It involves a lattice specific part that is qu adratic in the vertex functional and classically irrelevant. We show that i t stays irrelevant under renormalization. This means that in the continuum limit the (standard) chiral symmetry becomes restored. In particular, the f lavour mixing cur-rent does not require renormalization. (C) 2000 Elsevier Science B.V. All rights reserved.