04.20.-q Classical general relativity (see also 02.40.-k Geometry, differential geometry, and topology)
- 04.20.Cv Fundamental problems and general formalism (1)
- 04.20.Dw Singularities and cosmic censorship
- 04.20.Ex Initial value problem, existence and uniqueness of solutions
- 04.20.Fy Canonical formalism, Lagrangians, and variational principles
- 04.20.Gz Spacetime topology, causal structure, spinor structure
- 04.20.Ha Asymptotic structure
- 04.20.Jb Exact solutions