Assessing the Detectability of Transitionally Precessing Binary Black Holes in Next-Generation Gravitational Wave Detectors.

Next-generation gravitational wave detectors promise to observe binary black hole (BBH) signals orders of magnitude louder and longer-lived than present detectors. Such detections necessitate more accurate waveform models, particularly when modeling gravitational wave (GW) higher modes (HMs). BBHs whose spins are misaligned from their orbital plane undergo precession, observable through these GW HMs. Transitional precession (TSP) represents a nonlinear phenomenon in near-retrograde precessing systems where they lose gyroscopic stability and dramatically flip their precession axis, a phenomenon not presently modelable outside of numerical simulations. We map the parameter space of TSP systems using a suite of Post-Newtonian simulations; we also perform calculations of waveform properties and SNR to determine detectable regions for TSP in next-generation GW detectors. These detectable regions will inform the targeted numerical relativity simulations needed to better calibrate the next iterations of semi-analytical GW models for TSP.