# Tag Info

This Bardeen counterterm is an elusive beast, I must say. Yet I will share what I have found and understand: Define a $\mathrm{U}(1)$ gauge theory by writing its action in left- and right-handed chiral spinors as  S_{\mathrm{chiral}}[A] = \int \bar \psi_L (\mathrm{i} {\not \hspace{-4px} \partial} - \not \hspace{-5px} A)\psi_L + \bar \psi_R (\mathrm{i} ...