Abstract
In this work a new numerical technique to prepare Cauchy data for the initial value problem formulation of Einstein's field equations is presented. Directly inspired by the exterior asymptotic gluing result of Corvino (2000) our (pseudo)-spectral scheme is demonstrated under the assumption of axisymmetry so as to fashion composite Hamiltonian constraint satisfying initial data featuring internal binary black holes as glued to exterior Schwarzschild initial data in isotropic form. The generality of the method is illustrated in a comparison of the ADM mass of gluedinitial data sets featuring internal binary black holes as modelled by Brill-Lindquist and Misner data. In contrast to the recent work of Doulis and Rinne (2016); Pook-Kolb and Giulini (2018) we do not make use of the York-Lichnerowicz conformal framework to reformulate the constraints.