Schwinger and Adler have discovered that if the $A_1-\omega -\rho$ off-shell vertex function is linearly divergent, then the axial-vector Ward identity for the $A_1-\omega -\rho$ vertex contains an extra model-dependent term. It is shown here that no extra term occurs in the Ward identities for the $A_1-\rho -\pi$ system when the $A_1-A_1-\rho$ vertex is linearly divergent.

• Received 13 January 1969

DOI:https://doi.org/10.1103/PhysRev.181.1909