Exact cosmological black hole solutions in scalar tensor vector gravity

Abstract

We find an exact solution of scalar-tensor-vector gravity field equations that represents a black hole embedded in an expanding universe. This is the first solution of such a kind found in the theory. We analyze the properties of the apparent horizons as well as the essential singularities of the metric, and compare them with the McVittie spacetime of general relativity. Depending on the cosmological model adopted and the value of the free parameter of the theory, the solution describes a cosmological black hole, an inhomogeneity in an expanding universe, or a naked singularity. We use the results to set further constraints on the free parameters of the theory and we study geodesic motion in this spacetime.