The axial anomaly of Ginsparg-Wilson fermion

Abstract

The axial anomaly of Ginsparg-Wilson fermion operator $D$ is discussed in general for the operator $R$ which enters the chiral symmetry breaking part in the Ginsparg-Wilson relation. The axial anomaly and the index of $D$ as well as the exact realization of the Atiyah-Singer index theorem on the lattice are determined solely by the topological characteristics of the chirally symmetric operator $D_c$ in the chiral limit $R\to 0$.

Comments: 12 pages, latex, references updated, the version to appear in Phys. Lett. B