Revisiting the Evidence for Precession in GW200129 with Machine Learning Noise Mitigation

GW200129 is claimed to be the first -ever observation of the spin -disk orbital precession detected with gravitational waves (GWs) from an individual binary system. However, this claim warrants a cautious evaluation because the GW event coincided with a broadband noise disturbance in LIGO Livingston caused by the 45 MHz electro-optic modulator system. In this paper, we present a state-of-the-art neural network that is able to model and mitigate the broadband noise from the LIGO Livingston interferometer. We also demonstrate that our neural network mitigates the noise better than the algorithm used by the LIGO-VirgoKAGRA Collaboration. Finally, we reanalyze GW200129 with the improved data quality compared to the data used by the LIGO-Virgo-KAGRA Collaboration and show that the evidence for precession is still observed.