U2-2016
Title: Probing black hole spin precession from the ringdown
Abstract:
At the final stage of a binary black hole coalescence, known as the ringdown, the merged remnant emits gravitational waves as it relaxes toward a stationary Kerr black hole. Far from the merger, the signal can be described as a superposition of quasi-normal modes, whose frequencies depend only on the remnant’s mass and spin, while their amplitudes encode information about the progenitor binary.
In this talk, I will present recent work on the first implementation of a ringdown amplitude model that incorporates spin-induced precession, and its application to a re-analysis of GW190521— a short, merger-dominated event with competing interpretations— using a simulation-based inference framework tailored to ringdown signals.
Comparing non-precessing and precessing analyses, we find modest but systematic shifts in the inferred remnant properties and in the amplitudes of subdominant modes. For this event, however, the ringdown alone does not provide compelling evidence for spin precession.
These results demonstrate the feasibility of precessing, physics-informed ringdown modelling and highlight the potential of the ringdown as a clean probe of black hole spin dynamics.