Abstract

Initial data forms the starting point of any evolution. For simulations of binary black hole coalescence, the initial data should resemble as closely as possible a snapshot of a "true" inspiraling binary black hole. The quasi-equilibrium method combined with inner boundary conditions based on isolated horizons, provides a promising approach toward astrophysical initial data. In this talk, I describe this method and present numerical results. Furthermore, I report recent results about non-unique solutions of the Einstein constraint equations.