EVAPORATION OF ROTATING BLACK-HOLES AND THE EQUIVALENCE PRINCIPLE

This article is an investigation of the physics which underlies Hawking radiation from rotating black holes. It is shown that a global scalar field theory which is compatible with the equivalence principle demands that a rotating black hole in isolation experience thermal evaporation. The main goal of this paper is to attain a physical understanding of the phenomenon with a particular emphasis on computing the renormalized stress-energy tensor in the asymptotic zones, near the event horizon and at stationary infinity. This tensor is shown to be a measure of the change in the zero-point oscillations of the local field theory which is formulated by inertial observers during free fall, as compared to a global standard. An external onlooker sees the zero-point energy in a freely falling coordinate patch decrease as it approaches the horizon. This translates to a negative energy density of the field, near the horizon, in the components of the renormalized stress-energy tensor. The external onlooker interprets the zero-point energy lost during free fall as an outgoing stream of particle-antiparticle pairs.