Dynamical shift condition for unequal mass black hole binaries

TL;DR

This paper investigates the role of a damping factor in numerical simulations of unequal mass black hole binaries, proposing non-constant damping forms to improve waveform accuracy for varied mass ratios.

Contribution

It introduces explicit non-constant damping functions tailored for unequal mass binaries, enhancing simulation stability and waveform fidelity.

Findings

Non-constant damping improves waveform accuracy for unequal mass ratios.

Analysis shows tailored damping reduces numerical artifacts.

Waveform comparisons favor the proposed damping forms.

Abstract

Certain numerical frameworks used for the evolution of binary black holes make use of a gamma driver, which includes a damping factor. Such simulations typically use a constant value for damping. However, it has been found that very specific values of the damping factor are needed for the calculation of unequal mass binaries. We examine carefully the role this damping plays, and provide two explicit, non-constant forms for the damping to be used with mass-ratios further from one. Our analysis of the resultant waveforms compares well against the constant damping case.