Speaker
Description
The ringdown phase of a binary black-hole merger provides a uniquely clean probe of strong-field gravity, as it can be modelled with minimal assumptions. The quasi-normal-mode spectrum encodes the mass and spin of the Kerr remnant, while the excitation of these modes depends on the properties of the progenitor binary. In this work, we present the first implementation of a recently developed amplitude model that incorporates spin precession into a simulation-based inference framework designed specifically for ringdown signals. We apply this to GW190521- a short, merger-dominated event with competing interpretations- performing both spin-aligned and precessing analyses. Allowing for precession produces modest but systematic shifts in the inferred remnant parameters and in the amplitudes of subdominant modes, although the ringdown alone does not provide compelling evidence for precession. These results demonstrate the feasibility of physics-informed, precessing ringdown modelling and pave the way toward identifying spin precession directly from the ringdown stage, where waveform systematics are expected to be substantially reduced.