3D simulations of linearized scalar fields in Kerr spacetime

We investigate the behavior of a dynamical scalar field on a fixed Kerr background in Kerr-Schild coordinates using a (3+1)-dimensional spectral evolution code, and we measure the power-law tail decay that occurs at late times. We compare evolutions of initial data proportional to f(r)Y_lm(θ,φ), where Y_lm is a spherical harmonic and (r,θ,φ) are Kerr-Schild coordinates, to that of initial data proportional to f(r_BL)Y_lm(θ_BL,φ), where (r_BL,θ_BL) are Boyer-Lindquist coordinates. We find that although these two cases are initially almost identical, the evolution can be quite different at intermediate times; however, at late times the power-law decay rates are equal.