Gauge Unification of Basic Forces, Particularly of Gravitation with Strong Interactions

The presently accessible range of physical phenomena appears to be governed by the four familiar types of basic forces, mediated either by spin-one or spin-two quanta (TABLE 1). The spins of the mediating quanta, spin-one for weak, electromagnetic (EM), and strong forces, and spin-two for strong and gravitational forces, appear to correspond to two of the deepest and most elegant theoretical structures based on the gauge principle that we know of. These structures are shown in TABLE^. Whereas the theme of a Yang-Mills unification of weak, EM, and strong forces (motivated by the shared characteristic of all of these forces being mediated by spinone gauge particles) has been fairly well emphasized, comparatively less attention has been paid to the spin-two characteristic of the strong force, its resemblances to gravity, and the possible unification of these two forces by use of Einstein-Weyl gauge ideas. It is my principal purpose to motivate such a unification, though in the first part of the paper I shall also briefly review the spin-one unification aspects of weak, EM, and strong interactions. Tentatively, then, I shall be proposing a “Puppi” type of tetrahedral interrelation of fundamental forces, with the strong force playing a pivotal role due to its mediation through both spin-one and spin-two quanta (FIGURE 1). I will first give a summary of the important points concerning the linkages represented by this tetrahedron.