Gravitational Wilson loop in discrete quantum gravity

Results for the gravitational Wilson loop, in particular, the area law for large loops in the strong coupling region, and the argument for an effective positive cosmological constant, discussed in a previous paper, are extended to other proposed theories of discrete Euclidean quantum gravity in the strong coupling limit. We argue that the area law is a generic feature of almost all nonperturbative Euclidean lattice formulations, for sufficiently strong gravitational coupling. The effects on gravitational Wilson loops of the inclusion of various types of light matter coupled to lattice quantum gravity are discussed as well. One finds that significant modifications to the area law can only arise from extremely light matter particles. The paper ends with some general comments on possible, physically observable, consequences.