On the Spectrum of the Radiation from a Naked Singularitry

TL;DR

This paper investigates the quantum radiation emitted during the collapse leading to a naked singularity, revealing that its spectrum differs from black hole radiation and lacks a simple black body interpretation.

Contribution

It derives the radiation spectrum for a naked singularity formed from dust collapse, showing it is non-thermal and distinct from black hole radiation.

Findings

Radiation flux near the Cauchy horizon diverges as inverse square of distance.

The spectrum of naked singularity radiation is non-black body.

No simple interpretation of the spectrum as thermal radiation.

Abstract

In the final stages of collapse, quantum radiation due to particle creation from a naked singularity is expected to be significantly different from black hole radiation. In certain models of collapse it has been shown that, neglecting the back reaction of spacetime, the particle flux on future null infinity grows as the inverse square of the distance from the Cauchy horizon. This is to be contrasted with the flux of radiation from a black hole, which approaches a constant (inversely proportional to the square of its mass) in the neighborhood of its event horizon. The spectrum of black hole radiation 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 collapse of a marginally bound inhomogeneous dust cloud and show that the spectrum is not black body and admits no simple interpretation.