electrovacuum solutions; it includes the Reissner–Nordström electrovacuum, Ernst–Maxwell electrovacuums: this is the family of all stationary axisymmetric electrovacuum solutions; it includes the Kerr–Newman electrovacuum, Beck–Maxwell electrovacuums: all nonrotating cylindrically symmetric electrovacuum solutions, Ehlers–Maxwell electrovacuums: all stationary cylindrically symmetric electrovacuum solutions, Szekeres electrovacuums: all pairs of colliding plane waves, where each wave may contain both gravitational and electromagnetic radiation; these solutions are null electrovacuums outside the interaction zone, but generally non-null electrovacuums inside the interaction zone, due to the non-linear interaction of the two waves after they collide. Many pp-wave spacetimes admit an electromagnetic field tensor turning them into exact null electrovacuum solutions. See also Classification of electromagnetic fields Exact solutions in general relativity Lorentz group References See section 5.4 for the Rainich conditions, section 19.4 for the Weyl–Maxwell electrovacuums, section 21.1 for the Ernst-Maxwell electrovacuums, section 24.5 for pp-waves, section 25.5 for Szekeres electrovacuums, etc. The definitive resource on colliding plane waves, including the examples mentioned above. Exact solutions in general relativity Electromagnetism