Host: S. Borhanian
Impact of inaccurate waveform models on GW science in upcoming LVK observations and future observatories
Gravitational-wave (GW) observations of binary black-hole (BBH) coalescences are expected to address outstanding questions in
astrophysics, cosmology, and fundamental physics. Inference of BBH parameters relies on waveform models, and realizing the full discovery
potential of upcoming LIGO-Virgo-KAGRA observing runs and new ground-based facilities (such as the Einstein Telescope and Cosmic Explorer) hinges on the accuracy of these waveform models. Using linear-signal approximation methods and Bayesian analysis, we start to assess our readiness for what lies ahead using two state-of-the-art quasi-circular, spin-precessing models: SEOBNRv5PHM and IMRPhenomXPHM. Our findings reveal that current waveforms fail to enable the unbiased measurement of the Hubble-Lemaître parameter and sky localization. Moreover, highly asymmetric systems within the lower BH mass gap exhibit biased measurements of the secondary-companion mass, which impacts the physics of both neutron stars and formation channels. Similarly, we deduce that the primary mass of massive binaries (> 60M⊙) will also be biased, affecting supernova physics. Future progress in analytical calculations and numerical-relativity simulations, crucial for calibrating the models,
must target regions of the parameter space with significant biases to develop more accurate models. Only then can precision GW astronomy fulfill the promise it holds.