THE LIGHT-CONE AT INFINITY,

Abstract : From the point of view of the conformal structure of space-time, points at infinity can be treated on the same basis as finite points. Minkowski space can be completed to a highly symmetrical conformal manifold by the addition of a null cone at infinity - the absolute cone. Owing to their conformal invariance, zero rest-mass fields can be studied on the whole of this conformal manifold. The behaviour of the fields on the absolute cone can be used to define the radiation fields. General relativity can be treated from this point of view if the gravitational field is represented by an expression originally equal to the Weyl tensor but which transforms slightly differently under conformal transformation. (Author)