Accretion disks around the Gibbons–Maeda–Garfinkle–Horowitz–Strominger charged black holes

Abstract

Abstract It seems surprising that the emissivity properties of the accretion disk (à la Page and Thorne) surrounding the Gibbons–Maeda–Garfinkle–Horowitz–Strominger (GMGHS) black holes of heterotic string theory have not yet been studied. To fill this gap in the literature, we study the emissivity properties of the thin accretion disks around these black holes both in the Einstein and in the string frame using the Page–Thorne model. For illustration, we choose as a toy model a stellar-sized spherically symmetric black hole and find that, while the emissivity properties do not significantly differ from those of Reissner–Nordström and Schwarzschild black holes, they remarkably differ at GMGHS extreme limits corresponding to naked singularity and wormhole at higher frequencies. These differences provide a novel way to speculatively conclude about different types of objects from the observational point of view.