Foundations of multiple black hole evolutions

Understand

We present techniques for long-term, stable, and accurate evolutions of multiple-black-hole spacetimes using the `moving puncture' approach with fourth- and eighth-order finite difference stencils.

• We use these techniques to explore configurations of three black holes in a hierarchical system consisting of a third black hole approaching a quasi-circular black-hole binary, and find that, depending on the size of the binary, the resulting encounter may lead to a prompt merger of all three black holes, production of a highly elliptical binary (with the third black hole remaining unbound), or disruption of the binary (leading to three free black holes).
• We also analyze the classical Burrau three-body problem using full numerical evolutions.
• In both cases, we find behaviors distinctly different from Newtonian predictions, which has important implications for N-body black-hole simulations.