The surface term in gauge theories

Abstract

The importance of the surface term in the action integral in gauge theories is pointed out. It contains additional dynamical variables other than those contained in the Lagrangian density. The additional variables play the role of collective coordinates for the quantization of 'tHooft-Polyakov monopole solution. In general they are necessary if the generalized total change of the system is non-zero. They serve to select a boundary condition of the solution of classical equations of motion, about which the quantum mechanical perturbative expansion should be done. We obtained the Schwinger quantization condition for the dyon: Q_g = integer.