On topological defect formation in the process of symmetry breaking phase transitions

By resorting to some results in quantum field theories with spontaneous breakdown of symmetry we show that an explanation based on microscopic dynamics can be given of the fact that topological defect formation is observed during the process of non-equilibrium phase transitions characterized by a non-zero order parameter. We show that the Nambu-Goldstone particle acquires an effective non-zero mass due to the boundary (finite volume) effects and this is related with the size of the defect. We also relate such volume effect with temperature effect.