Event Horizons from black-hole rings

We construct and evolve non-rotating vacuum initial data with a ring singularity, based on a simple extension of the standard Brill-Lindquist multiple black-hole initial data, and search for event horizon with spatial slices that are topologically tori. We find, that it is not possible to produce a finite-sized toroidal horizon, which only occurs in a singular limit where the horizon width has zero size, indicating the presence of a naked singularity.