Fields, masses and coupling constants appearing in the Lagrangian are perturbatively divergent quantities which become acceptable by renormalization procedures. As a consequence, the new quantities are function of the energy and the functional dependence is governed by the Renormalization Group Equations (RGE). For the gauge coupling constants these equations have the form where is the Callan-Symanzik … Continue reading Implications


Electromagnetic interactions

The electromagnetic interaction is described by a gauge theory headed by the symmetry group whose density of the Lagrangian can be written as: where is the electromagnetic field tensor and is the gauge covariant derivative, with indicating the covariant four-potential of the electromagnetic field, generated by the charge ; is the external field due to … Continue reading Electromagnetic interactions