Normal-Product Quantization of Currents in Lagrangian Field Theory

Abstract

Techniques for quantizing currents in Lagrangian field theory are developed with the aid of Zimmermann's normal products. These methods greatly simplify the derivation of single-current generalized Ward identities and may be used to justify the heuristic use of formal arguments in discussing broken symmetries. Applications to the energy-momentum tensor in the $A^4$ model and to the current of broken orthogonal symmetry in a two-component scalar model are presented.