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Résumé |
In this talk, it will be shown that the Kerr metric describes a pair of self-dual and anti-self-dual Taub-NUT instantons, like the N and S poles of a bar magnet. The implications of this fact will be discussed. Firstly, it derives the Newman-Janis algorithm without an ambiguity: a mathematical procedure that generates spinning black hole solutions from non-spinning ones by means of a complex transformation, previously believed as merely a formal construct. Secondly, it uniquely determines the effective point-particle Lagrangian of Kerr black hole in post-Minkowskian gravity, based on the topological nature of the gravitational Dirac string (Misner string) associated with the NUT charges. This off-shell construction resolves the longstanding struggle that the gravitational dynamics of Kerr black holes at the second post-Minkowskian order is not uniquely, or easily, determinable from the scattering amplitudes methods. The gravitational Compton amplitude for Kerr black hole will be presented, which achieves correct factorizations without spurious poles in a simple manner. Finally, a new chapter of relativity will be proposed, in which spin is intrinsically unified into spacetime: "spinspacetime”. |
