Filling the holes: Evolving excised binary black hole initial data with puncture techniques

TL;DR

This paper demonstrates that the exterior gravitational waveforms and late-time solutions of binary black hole mergers are unaffected by the choice of initial interior data, including constraint-violating junk data, when using puncture techniques.

Contribution

It shows that filling excised regions of initial data with arbitrary smooth data does not affect the evolution outcomes in binary black hole simulations.

Findings

Waveforms are similar regardless of initial interior data.

Interior solutions evolve to constraint-satisfying states.

Minor differences observed between irrotational and corotational binaries.

Abstract

We follow the inspiral and merger of equal-mass black holes (BHs) by the moving puncture technique and demonstrate that both the exterior solution and the asymptotic gravitational waveforms are unchanged when the initial interior solution is replaced by constraint-violating ``junk'' initial data. We apply this result to evolve conformal thin-sandwich (CTS) binary BH initial data by filling their excised interiors with arbitrary, but smooth, initial data and evolving with standard puncture gauge choices. The waveforms generated for both puncture and filled-CTS initial data are remarkably similar, and there are only minor differences between irrotational and corotational CTS BH binaries. Even the interior solutions appear to evolve to the same constraint-satisfying solution at late times, independent of the initial data.