On the spectrum of the radiation from a naked singularity

In the final stages of collapse, quantum radiation due to particle creation from a naked singularity is expected to be significantly different from bl ack hole radiation. In certain models of collapse it has been shown that, n eglecting the back reaction of spacetime, the particle flux on future null infinity grows as the inverse square of the distance from the Cauchy horizo n. This is to be contrasted with the flux of radiation from a black hole, w hich approaches a constant (inversely proportional to the square of its mas s) in the neighborhood of its event horizon. The spectrum of black hole rad iation is identical to that of a black body at temperature T = (8 pi M)(-1) . We derive the radiation spectrum for a naked singularity formed in the co llapse of a marginally bound inhomogeneous dust cloud and show that the spe ctrum is not black body and admits no simple interpretation. (C) 1998 Publi shed by Elsevier Science B.V. All rights reserved.