Assesing two analytic gravitational waves models for binary black hole mergers*

The peak in the gravitational wave (GW) signal emitted at the merger of a binary black hole (BBH) system produces the loudest signal in the detectors. Modeling such signals requires numerical relativity (NR) to account for the nonlinear physics during the collision, but computer simulations are inherently complex, costly, and affected by numerical errors. In order to bypass this problem, two analytical models for the merger have been developed: Implicit Rotating Source (IRS) and Backwards one Body (BoB). In this work, we assess the performance of those models by comparing them with numerical data, and identifying their strengths and weaknesses. Our main finding reveals discrepancies in amplitude, but overall excellent accord in frequency for the BoB model, comparable to IRS and to NR simulations, having the added advantage that it depends only indirectly on numerical data, it accounts for spin, and it offers a seamless fit with the analytical formalisms for the inspiral. By independently evaluating and testing those models, we bring evidence of their reproducibility, thus upholding high scientific standards, and enable readers to evaluate our results themselves.