High accuracy simulations of Kerr tails: coordinate dependence and higher multipoles

We investigate the late-time behavior of a scalar field on a fixed Kerr background using a 2 + 1 dimensional pseudo-spectral evolution code. We compare evolutions of pure axisymmetric multipoles in both Kerr–Schild and Boyer–Lindquist coordinates. We find that the late-time power-law decay rate depends upon the slicing of the background, confirming previous theoretical predictions for those decay rates. The accuracy of the numerical evolutions is sufficient to decide unambiguously between competing claims in the literature.