In Peskin's QFT book page 294, he formally addressed the quantization of EM field,
propagotorEM=−igμνk2+iϵ
Now that we have the functional integral quantization method at our command, let us apply it to the derivation of this expression.
Consider the functional integral
∫DAeiS[A],
Actually I expected to see how he would derive the generating functional ∫DAei(S[A]+JμAμ) from the canonical quantization before proceeding on to introduce the Faddeev-Popov trick.
So is there a way to do this derivation, i.e., from the operator formalism using Hamiltonian, or we must presume the validity of this path integral as a starting point, which is probably what Peskin did(I guess)?
This post imported from StackExchange Physics at 2014-05-04 11:29 (UCT), posted by SE-user LYg