Gravitational waves in general relativity X. Asymptotic expansions for the Einstein-Maxwell field

Abstract This paper contains asymptotic expansions for the Einstein-Maxwell field representing radiation of gravitational and electromagnetic energy from a bounded source of matter and charge. It is shown that the flow of radiation is determined by four news functions which can be considered as two functions giving the gravitational part of the news and two for the electromagnetic part. Together with initial data specified on a null cone these four functions completely determine the behaviour of the system. It is shown that the gravitational and electromagnetic news functions contribute separately to a decrease in the mass of the source. Finally the Newman-Penrose conserved quantities are obtained and an interpretation of the invariant λ-function is given.