Massive Vector Fields

Abstract

According to Maxwell’s equations in the form (6.30) and to the linearized version of Einstein’s equations (9.14), formally identical, a generic system of accelerated charged bodies emits electromagnetic as well as gravitational waves, both propagating at the velocity of light. In basis of the classical equations (6.30) and (9.14), at the quantum level the electromagnetic radiation is composed of photons and the gravitational one of gravitons, both particles of zero mass. Similarly, the dynamics of the eight gluon vector potentials, mediating the strong interactions, at the linearized level is described by a Lagrangian analogous to the one of the electromagnetic field, see Eq. (3.42), and, correspondingly, also gluons are massless particles propagating at the velocity of light. However, according to the color-confinement paradigm inherent in Quantum Chromodynamics, the theory describing the strong interactions at the quantum level, the mediators of these interactions cannot propagate freely, and so in nature there exist no gluon waves.