How do you propose a black hole would lose matter (except via the slow Hawking radiation process)?
take a class like this one.
C161. Relativistic Astrophysics and Cosmology. (4) Three hours of lecture and one hour of discussion per week. Prerequisites: Physics 110A-110B; Physics 112 (may be taken concurrently). Formerly C160B and Astronomy C160B. Elements of general relativity. Physics of pulsars, cosmic rays, black holes. The cosmological distance scale, elementary cosmological models, properties of galaxies and quasars. The mass density and age of the universe. Evidence for dark matter and dark energy and concepts of the early universe and of galaxy formation. Reflections on astrophysics as a probe of the extrema of physics. Also listed as Astronomy C161. (SP) Boggs, Davis, Holzapfel, A. Lee, Ma, Quataert