Exécution de notre outil de synthèse sur un nouvel article

Résumé : It is shown that black hole spacetimes in classical Einstein gravity are characterized by, in addition to their ADM mass M , momentum P ~ , angular momentum J ~ and ~ an infinite head of supertranslation hair. The distinct black holes boost charge K, are distinguished by classical superrotation charges measured at infinity. Solutions with supertranslation hair are diffeomorphic to the Schwarzschild spacetime, but the diffeomorphisms are part of the BMS subgroup and act nontrivially on the physical phase space. It is shown that a black hole can be supertranslated by throwing in an asymmetric shock wave. A leading-order Bondi-gauge expression is derived for the linearized horizon supertranslation charge and shown to generate, via the Dirac bracket, supertranslations on the linearized phase space of gravitational excitations of the horizon. The considerations of this paper are largely classical augmented by comments on their implications for the quantum theory.