Séminaire de Physique ThéoriqueGravitational waves from localized sources in the Bondi-Sachs formalism
Ali Seraj (Queen Mary University of London)
Friday 30 June 2023 11:00 - Salle des séminaires - Salle 1180, bâtiment E2
The asymptotic Bondi-Sachs formalism is a convenient setup to study various gravitational-wave observables, such as fluxes of conserved quantities or the canonical structure of radiative phase space. The Bondi shear, which characterizes the gravitational-wave strain, is not constrained by Einstein equations and is thus free data in this setup. However, to obtain the Bondi shear for a given source, one needs to combine this approach with other methods which permit studying the generation of waves from sources. In this talk, I will describe the interplay between Bondi-Sachs and the post-Newtonian/post-Minkowskian formalism. This analysis allows us to infer several interesting properties of the spacetime geometry; including 1) its global features, such as the peeling property or the late-time behavior of the waveform, and 2) check the conservation of asymptotic charges, in particular, the ten Newman-Penrose charges.