The path integral quantization of gauge theories leads to an effective Lagrangian denoted by L_eff. Its associated equation of motion is of the form d_A^* F_A + (1/2) J_A = 0, where J_A is the vacuum polarization current arising from propagation of quantum fields around the background field A. In this paper we will give a more detailed description of the current J_A.
On the effective Yang-Mills Lagrangian and its equation of motion / Cavicchioli, Alberto; F., Hegenbarth. - In: JOURNAL OF GEOMETRY AND PHYSICS. - ISSN 0393-0440. - STAMPA. - 25:(1998), pp. 69-90.