Stochastic Gravity and Self-Organized Critical Cosmology

Abstract

A stochastic theory of gravity is described in which the metric tensor is a random variable such that the spacetime manifold is a fluctuating physical system at a certain length scale. A general formalism is described for calculating probability densities for gravitational phenomena in a generalization of general relativity (GR), which reduces to classical GR when the magnitude of the metric fluctuations is negligible. Singularities in gravitational collapse and in big-bang cosmology have zero probability of occurring. A model of a self-organized critical universe is described which is independent of its initial conditions.