Particle-physics inspired techniques improve the accuracy of spin effects in gravitational-waveform models
The more sensitive gravitational-wave detectors become, the more accurately scientists need to model the waveforms used to search for and analyze the signals. Looking for new methods to refine such models, inspiration can be found in particle physics, where scattering is the fundamental process of interest. Considering the scattering of two black holes together with an approximation in the mass-ratio of the binary, the authors were able to calculate the spin-orbit interaction through one order beyond the known accuracy in state-of-the art waveform models.
Exploiting simple yet remarkable properties of relativistic gravitational scattering, we use first-order self-force (linear-in-mass-ratio) results to obtain arbitrary-mass-ratio results for the complete third-subleading post-Newtonian (4.5PN) corrections to the spin-orbit sector of spinning-binary conservative dynamics, for generic (bound or unbound) orbits and spin orientations. We thereby improve important ingredients of models of gravitational waves from spinning binaries, and we demonstrate the improvement in accuracy by comparing against aligned-spin numerical simulations of binary black holes.