Nonthermal Spectrum of Hawking Radiation

TL;DR

This paper argues that Hawking radiation's spectrum must be nonthermal to resolve the black hole information paradox, showing that the commonly assumed thermal spectrum results from an approximation.

Contribution

It demonstrates that the thermal spectrum of Hawking radiation arises from the geometric optics approximation and provides a more accurate derivation revealing a nonthermal spectrum.

Findings

Thermal spectrum results from geometric optics approximation.

More accurate derivation yields nonthermal Hawking radiation.

Nonthermal spectrum can resolve the information loss paradox.

Abstract

We show that for the thermal spectrum of Hawking radiation black hole's information loss paradox may still be present, even if including the entanglement information stored in the entangled Minkowski vacuum. And to avoid this inconsistency, the spectrum of Hawking radiation must be nonthermal. After reconsidering the derivation of Hawking effect, we find that the thermal spectrum is actually resulted from the geometric optics approximation in deriving the Bogolubov coefficients. When treated a little more accurately, we obtain some nonthermal spectrum for the Hawing radiation, which reduces to the thermal one in the geometric optics approximation.