PhD Seminar: Joan Llobera Querol, Estudiant del Programa de Doctorat de Física — Aligning and Constructing Hybrid Waveforms for Precessing Binaries

Precessing binaries exhibit complex dynamics that significantly modulate the emitted gravitational waveform. Describing such systems is challenging due to the lack of a canonical choice for coordinate frames and other non-physical parameters. Therefore, we consider a binary’s description and waveform as an equivalence class, factoring out the influence of these arbitrary mathematical choices.

Constructing hybrid waveforms for applications such as model calibration requires the integration of waveforms from different perspectives, including numerical relativity, post-newtonian theory and waveform models. However, these descriptions generally use different non-physical parameters, which may prevent them to align seamlessly. Here, I review and present two methods to resolve these degeneracies and align descriptions of precessing systems. Both methods are robust, and their use and effectiveness is demonstrated with several NR simulations and different approximants. Results provide a systematic approach for accurately constructing long and accurate waveforms of precessing systems in the quasicircular case.