Electron-positron outflow from black holes

Cosmological gamma-ray bursts (GRBs) appear as the brightest transient phenomena in the Universe. The nature of their central engine is a missing link in the theory of fireballs to stellar mass progenitors. and may be associated with low mass black holes. In contact with an external magnetic field B, black hole spin produces a gravitational potential on the wave function of charged particles. We show that a rapidly rotating black hole of mass M produces outflow from initially electrostatic equilibrium with normalized isotropic emission similar to 10(48)(B/B-c)(2)(M/7M(circle dot))(2) sin(2) theta erg/s, where B-c = 4.4 x 10(13) G. The half-opening angle satisfies theta greater than or equal to root B-c/3B. The outflow proposed as input to GRB fireball models.