Magnetising de Sitter and Anti-de Sitter spacetimes

We attempt to magnetise the de Sitter (dS) and Anti-de Sitter (AdS) spacetimes in spherical symmetry. First, the weak field case is considered where Maxwell's equation is solved to find magnetic fields in fixed dS/AdS backgrounds. For strong magnetic fields we consider Einstein-Maxwell gravity with a gravitating fluid source. With gravitational backreaction of the magnetic field taken into account, the strong fields deform the dS/AdS spacetime, resulting in a dS/AdS-type analogue of the Melvin magnetic universe. This solution is obtained via a Harrison-like transformation, along with appropriate transformations of the fluid energy and pressures. Some of its physical and geometrical properties of the solution are studied.