Computing the quasinormal modes and eigenfunctions for the Teukolsky equation using horizon penetrating, hyperboloidally compactified coordinates

We study the quasinormal mode eigenvalues and eigenfunctions for the Teukolsky equation in a horizon penetrating, hyperboloidally compactified coordinate system. Following earlier work by Zenginoglu (2011 Phys. Rev. D 83 127502), we show that the quasinormal eigenfunctions (QNEs) for the Teukolsky equation are regular from the black hole horizon to future null infinity in these coordinates. We then present several example QNE solutions, and study some of their properties in the near-extremal Kerr limit.