Strong cosmic censorship conjecture

Consider generic initial data for a suitable Einstein-matter system or for the Einstein vacuum equations, and let the maximal Cauchy development be the spacetime arising from those data. A spacetime is inextendible when it admits no extension with the relevant regularity across its boundary. Strong cosmic censorship conjecture. For generic initial data for a suitable Einstein-matter system or for the Einstein vacuum equations, the maximal Cauchy development arising from the initial data is inextendible. This conjecture predicts that generic gravitational evolution does not admit extensions beyond its maximal Cauchy development; its precise formulation and resolution depend on the matter model and regularity class, and remain open in the generality stated here.