Abstract. There are several definitions in the literature of the notion of total angular momentum in general relativity. However, none of them can be said to capture the physical notion of intrinsic angular momentum of the sources in the presence of gravitational radiation. We present a definition of angular momentum for radiative spacetimes which does not suffer from any ambiguity of supertranslations. We have succeeded in providing an appropriate notion of intrinsic angular momentum and, at the same time, a definition of centre of mass frame at future null infinity. This notion is required in calculations involving radiation of angular momentum, as, for example, is expected in binary coalescence of black holes.

PACS numbers: 04.20.−q, 04.20.Cv, 04.20.Ha

Print publication: Issue 23 (7 December 2004)
Received 13 April 2004, in final form 23 September 2004
Published 9 November 2004