Testing the Boundary-to-Bound Correspondence with Numerical Relativity

The Boundary-to-Bound (B2B) correspondence, which connects orbital and radiative observables between bound and unbound orbits, has recently been introduced and demonstrated in the perturbative regime. We produce a large number of numerical relativity simulations of bound and unbound encounters between two nonspinning equal mass black holes in order to test this correspondence in the non-perturbative regime. We focus on testing the radiated energy and angular momentum, as well as orbital parameters such as the period and periastron advance. We find that, across a wide range of eccentricities, the B2B relationships do not hold in the non-perturbative regime, thereby placing a clear limit on the applicability of these relationships. We also approximate the separatrix between bound and unbound relativistic encounters as a function of their initial energies and angular momenta.