Recalculation of the spectrum of radiation emitted during gravitational collapse

TL;DR

This paper recalculates the radiation spectrum emitted during gravitational collapse using a simplified dust star model, identifying inconsistencies in earlier methods and deriving a thermal spectrum through asymptotic expansion.

Contribution

It introduces a systematic asymptotic approach to derive the radiation spectrum and clarifies previous inconsistencies in the theoretical derivations.

Findings

Derived a thermal radiation spectrum during collapse

Identified and corrected inconsistencies in prior derivations

Provided a more rigorous mathematical framework for spectrum calculation

Abstract

We recalculate the spectrum of radiation emitted from a collapsing star. We consider the simple model of a spherical star consisting of pressure-free dust and we derive the thermal spectrum via a systematic asymptotic expansion of the complete Bogolubov amplitude. Inconsistencies in previous derivations are pointed out.