Electromagnetic and Weak Radiative Corrections

The by far largest contribution to the anomalous magnetic moment is of pure QED origin. This is of course the reason why the measurements of \(a_e\) and \(a_\mu \) until not so long time ago may have been considered as precision tests of QED. The clear dominance to more than 99.99% of just one type of interaction, the interaction of the charged leptons e, \(\mu \) and \(\tau \) with the photon, historically, was very important for the development of QFT and QED, since it allowed us to test QED as a model theory under very simple, clean and unambiguous conditions.