Strong field scattering of black holes: Assessing resummation strategies

Abstract

Recent developments in post-Minkowskian (PM) calculations have led to a fast-growing body of weak-field perturbative information. As such, there is major interest within the gravitational wave community as to how this information can be used to improve the accuracy of theoretical waveform models. In this work, we build on recent efforts to validate high-order PM calculations using numerical relativity simulations. We present a new set of high-energy scattering simulations for equal-mass, nonspinning binary black holes, further expanding the existing suite of numerical relativity (NR) simulations. We outline the basic features of three recently proposed resummation schemes (the L-resummed model, the weob model and the SEOB-PM model) and compare the analytical predictions to our NR data. All of the models struggle to accurately capture the behavior at high energies, with common features including PM hierarchical shifts and divergences. The NR data are used to calibrate pseudo-5PM corrections to the scattering angle and to inform the effective one-body radial potentials. In each case, we argue that including higher-order information improves the agreement between the analytical models and NR, though the extent of improvement depends on how this information is incorporated and the choice of analytical baseline. Finally, we demonstrate that further resummation of the effective one-body radial potentials could be an effective strategy to improving the model agreement.