Strong-field scattering of two black holes: Numerical Relativity meets Post-Minkowskian gravity

TL;DR

This paper demonstrates that reformulating post-Minkowskian results within an Effective-One-Body framework yields highly accurate predictions of black hole scattering, validated against numerical relativity data, and introduces a novel method to extract gravitational potentials from simulations.

Contribution

It shows that EOB radial potentials based on PM results, especially with radiation reaction, match NR data well and introduces a new way to derive gravitational potentials directly from simulations.

Findings

EOB reformulation improves agreement with NR data

First extraction of radiation-reacted gravitational potential from NR

Radiation-reacted 4PM information enhances predictive accuracy

Abstract

We compare numerical relativity (NR) data on the scattering of equal-mass, non-spinning binary black holes to various analytical predictions based on post-Minkowskian (PM) results. While the usual sequence of PM-expanded scattering angles shows a rather poor convergence towards NR data, we find that a reformulation of PM information in terms of Effective-One-Body radial potentials leads to remarkable agreement with NR data, especially when using the radiation-reacted 4PM information. Using Firsov's inversion formula we directly extract, for the first time, from NR simulations a (radiation-reacted) gravitational potential describing the scattering of equal-mass, non-spinning binary black holes. We urge the NR community to compute more sequences of scattering simulations, so as to extend this knowledge to a wider region of parameter space.