The axial anomaly of Ginsparg-Wilson fermion

The axial anomaly of Ginsparg-Wilson fermion operator D is discussed in gen eral for the operator R which enters the chiral symmetry breaking part in t he Ginsparg-Wilson relation. The axial anomaly and the index of D as well a s the exact realization of the Atiyah-Singer index theorem on the lattice a re determined solely by the topological characteristics of the chirally sym metric operator D-c in the chiral limit R --> 0. (C) 1999 Published by Else vier Science B.V. All rights reserved.