Towards experimentally testing the paradox of black hole information loss

TL;DR

This paper investigates how deviations from thermal spectra in Hawking radiation, due to back reaction effects, could allow experimental testing of the black hole information loss paradox by analyzing energy covariances.

Contribution

It highlights the spectroscopic differences between thermal and nonthermal Hawking radiation spectra, proposing a method to distinguish them via energy covariances for testing the paradox.

Findings

Energy covariances are zero for thermal spectra.

Nonthermal spectra exhibit non-trivial energy covariances.

Counting covariances could experimentally test the information loss paradox.

Abstract

Information about the collapsed matter in a black hole will be lost if Hawking radiations are truly thermal. Recent studies discover that information can be transmitted from a black hole by Hawking radiations, due to their spectrum deviating from exact thermality when back reaction is considered. In this paper, we focus on the spectroscopic features of Hawking radiation from a Schwarzschild black hole, contrasting the differences between the nonthermal and thermal spectra. Of great interest, we find that the energy covariances of Hawking radiations for the thermal spectrum are exactly zero, while the energy covariances are non-trivial for the nonthermal spectrum. Consequently, the nonthermal spectrum can be distinguished from the thermal one by counting the energy covariances of successive emissions, which provides an avenue towards experimentally testing the long-standing "information loss paradox".