Luminosity of accretion disks around rotating regular black holes

Abstract

We consider thin accretion disks in the field of a class of rotating regular black holes. For this purpose, we obtain the radius of the innermost stable circular orbit, $r_{ISCO}$ and efficiency of accretion disk in converting matter into radiation $\eta$ with the aim of modeling the disk's emission spectrum. We consider a simple model for the disk's radiative flux, differential and spectral luminosity and compare the results with those expected from accretion disks around Kerr black holes. As a remarkable result, from our computations we find that both the luminosity of the accretion disk and the efficiency are larger in the geometry of rotating regular black holes for fixed and small values of the spin parameter $j$ with respect to those predicted with the Kerr metric for a black hole of the same mass. These results may have interesting implications for astrophysical black holes.