Yang-Mills formulation of gravitational dynamics

A Yang-Mills formulation of the dynamics of the gravitational field is given based on gauged spin transformations acting on a Dirac spin space. The gravitational field is carried by the spin connection following the point of view of Schrödinger, Laurent, and Loos. Differing from them, the dynamical statement is in a strictly Yang-Mills form. The Lagrangian for the model theory has a single massive Dirac field as source and is one investigated by Leutwyler but with a different end in mind. I compare it with Einstein's theory and show acceptable observational behavior for the theory in the usual circumstances. The theory is found to make contact with theories with torsion. A comparison between this work and previous work by Loos and Treat, Yang, Camenzind, and Carmeli is made.