The mass of the field can then cause the amplified modes to be trapped around the black hole, leading to an endless cycle of self-amplification.
The mechanism by which the black hole bomb functions is called superradiant instability.
It can also refer to one such method of creating such a runaway effect, a Penrose sphere with no means for energy to passively escape.
The idea that angular momentum and energy may be transferred from a rotating black hole to a particle being scattered by it was proposed by Roger Penrose in 1971.
The first discussion of a runaway effect, the black hole bomb, was explored by W. H. Press and S. A. Teukolsky in 1972.