Asymptotic Green’s function solutions of the general relativistic thin disc equations

ABSTRACT The leading order Green’s function solutions of the general relativistic thin disc equations are computed, using a pseudo-Newtonian potential and asymptotic Laplace mode matching techniques. This solution, valid for vanishing innermost stable circular orbit (ISCO) stress, is constructed by ensuring that it reproduces behaviour near-ISCO, Newtonian, global Wentzel–Kramers–Brillouin limits. Despite simplifications used in constructing this typically accurate, all values Kerr spin parameter at radii, to less than per cent full numerically calculated equations. These will be use studying time-dependent accretion discs surrounding black holes.