“…To ensure that the spacetime M is asymptotically flat, one requires the existence of a manifold S, consisting of S plus one additional point Λ, subject to certain conditions [8,20]. This point Λ is to be thought of as the 'asymptotic' point, in the sense that we can extend the metric h to the boundary of S. In particular, we require the existence of a scalar field, Ω such that hab = Ω 2 h ab is a metric on S, and at Λ one has Ω = 0, Da Ω = 0, and Da Db Ω = n hab for some n. Euclidean 3-space is asymptotically flat in the above sense with conformal factor Ω = r −2 , where r is the distance from some origin [8,9,20].…”