Black holes without Cauchy horizons and integrable singularities

Abstract

In general relativity, nonsingular black holes contain (at least) a Cauchy horizon, a null hypersurface beyond which determinism breaks down. Even though the strong cosmic censorship conjecture establishes the impossibility of extending spacetime beyond this region, in this paper we investigate how far we can go, without invoking this conjecture, in the building of a physically reasonable black hole without a Cauchy hypersurface. Following this reasoning, we find a black hole lacking of Cauchy horizon, asymptotically flat and satisfying either the strong or dominant energy condition. The above is possible by demanding integrable singularity for the Ricci scalar, whose direct consequence is the appearance of finite tidal forces. We show that the spacetime inside the event horizon represents a warped anti-de Sitter spacetime, which might be interpreted in terms of a finite superposition of configurations.