Srednicki — Quantum Field Theory · Problem 65.2

Canonical Quantization of Scalar Fields — Mark Srednicki

Physics — QFT · scalar-electrodynamics-gauge-invariance-ward-identity

Problem

Consider a gauge transformation

A^\mu \to A^\mu - \partial^\mu\Gamma

. Show that there is a transformation of

\varphi

that leaves the lagrangian of eqs. (65.1--65.4) invariant if and only if

Z_4 = Z_1^2/Z_2