Black Hole Excision for Dynamic Black Holes

TL;DR

This paper demonstrates advanced 3D black hole simulations using excision and dynamic gauges, achieving long-term stable evolutions and accurate waveform extraction for highly distorted, rotating black holes, surpassing previous 2D code capabilities.

Contribution

It introduces a method combining excision and dynamic gauge conditions for stable, long-term 3D black hole evolutions with accurate waveform extraction, even for highly distorted, rotating black holes.

Findings

Stable evolution of highly distorted black holes over long times

Accurate waveform extraction from 3D simulations

Significant improvement over 2D code longevity and accuracy

Abstract

We extend previous work on 3D black hole excision to the case of distorted black holes, with a variety of dynamic gauge conditions that are able to respond naturally to the spacetime dynamics. We show that the combination of excision and gauge conditions we use is able to drive highly distorted, rotating black holes to an almost static state at late times, with well behaved metric functions, without the need for any special initial conditions or analytically prescribed gauge functions. Further, we show for the first time that one can extract accurate waveforms from these simulations, with the full machinery of excision and dynamic gauge conditions. The evolutions can be carried out for long times, far exceeding the longevity and accuracy of even better resolved 2D codes. While traditional 2D codes show errors in quantities such as apparent horizon mass of over 100% by t = 100M, and crash by t = 150M, with our new techniques the same systems can be evolved for hundreds of M's in full 3D with errors of only a few percent.