The Blandford–Znajek process is a mechanism for the extraction of energy from a rotating black hole,[1][2] introduced by Roger Blandford and Roman Znajek in 1977.
[3] This mechanism is the most preferred description of how astrophysical jets are formed around spinning supermassive black holes.
[8] As the ergosphere causes the magnetosphere inside it to rotate, the outgoing flux of angular momentum results in extraction of energy from the black hole.
The Blandford–Znajek process requires an accretion disc with a strong poloidal magnetic field around a spinning black hole.
[4] Physicists Identify the Engine Powering Black Hole Energy Beams a Quanta Magazine article on the SANE vs MAD scenarios of the Blandford–Znajek process