0
$\begingroup$

In Peskin & Schröder's book, they wrote that there is no propagator for an Abelian field due to gauge invariance of the action, and then proposed a gauge fixing condition: $$\partial_\mu A^\mu = \omega(x)\tag{9.55}$$ in order to count each physical configuration once. Where $\omega(x)$ can be any scalar function.

I don't really understand what this equation means intuitively and how it actually helps counting each physical configuration only once?

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.