Strong cosmic censorship and topology change in four dimensional gravity

Understand

A physical interpretation of the recently discovered vast class of vacuum space-times, which stably violate the strong cosmic censor conjecture (in its usual broad formulation) in four dimensions, is exhibited.

• Namely, by elementary Morse theory we demonstrate that these geometries describe transitions between topologically different spacelike hypersurfaces.
• More precisely, in these four dimensional smooth vacuum space-times there exist three dimensional spacelike hypersurfaces which display an increasingly violent unbounded oscillation between topologically different closed, orientable three-manifolds as one moves towards the asymptotic region in their ambient space-times.
• Moreover this spatial oscillation appears as a cosmological redshift for late time observers.