Deriving Feynman rules from Lagrangian
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Nov29-06, 06:54 PM
Feynman came up with a method of getting a massive electron propagator from the massless one. It's mentioned as a footnote in his popular book "QED, the strange theory of matter and light". The idea is to resum a bunch of massless propagators that interact with vertices of "-im" to get an effective propagator that is massive.
Yes, that is exactly how I do it. I don't like it much though.