Spinning waveforms from classical amplitudes

20 Novembre 2023@14:00–15:00 Europe/Rome Fuso orario
AULA GRASSANO (https://infn-it.zoom.us/j/82247215673?pwd=em1GRklEYngwMGVBbVVBb2VoL1pvdz09)

Speakers: Riccardo Gonzo (University of Edinburgh)

We discuss how to compute scattering waveforms for theclassical two-body problem purely from on-shell five-point amplitudes,generalizing the KMOC (in-in) approach to radiative observables.Restricting to the case of two Kerr black-holes, we derive thetime-domain waveform at leading order in the Post-Minkowskian expansionand at quartic order in the spin by using analyticity arguments tobypass the conventional observable phase-space integration. The resultis expressed only in terms of the three-point amplitude and thefour-point Compton amplitude, which makes it easier to generalize forthe case of generic spinning bodies (i.e. with tidal effects). Finally,I will show how we can analytically continue the waveform fromhyperbolic to (eccentric) bound orbits.