Investigating Spin and Orbital Precession in Binary Black Hole Systems: Assessing the Role of Post-Newtonian Radiation-Reaction Terms

In this paper, I investigate whether spin precession — and consequently, orbital precession — is an artifact of the post-Newtonian radiation reaction (PN-RR) terms in <span class="sf">CBWaves</span>. To address this question, I conducted multiple simulations with <span class="sf">CBWaves</span> and compared the resulting orbits of the binary components. Alongside the inclusion of radiation-reaction terms, the initial eccentricity (\(e_{\mathrm {init}}\)), dimensionless spin magnitudes (\(\chi _{1,2}\)), and spin angles (\(\alpha \) and \(\beta \)) were systematically varied in the simulation loop to explore all possible contributing factors. The analysis of the resulting orbits indicates that radiation-reaction terms alone cannot fully account for the observed phenomenon. Abstract Published by the Jagiellonian University 2025 authors