Nonextreme and ultraextreme domain walls and their global space-times.

Non-extreme walls (bubbles with two insides) and ultra-extreme walls (bubbles of false vacuum decay) are discussed. Their respective energy densities are higher and lower than that of the corresponding extreme (supersymmetric), planar domain wall. These singularity free space-times exhibit non-trivial causal structure analogous to certain non-extreme black holes. We focus on anti-de Sitter– Minkowski walls and comment on Minkowski–Minkowski walls with trivial extreme limit, as well as walls adjacent to de Sitter space-times with no extreme limit.