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 nonperturbative 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 nonperturbative 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.