Extracting information about the initial state from the black hole radiation

TL;DR

This paper investigates how initial quantum states influence black hole radiation spectra, revealing potential for partial or full reconstruction of initial information, challenging classical collapse assumptions.

Contribution

It identifies classes of initial states that can be reconstructed from black hole radiation and emphasizes the importance of quantum effects in information retrieval.

Findings

Certain initial states can be partially reconstructed from radiation spectra.

Quantum treatment of collapse may enable more information retrieval.

Classical models overlook the information richness in black hole radiation.

Abstract

The crux of the black hole information paradox is related to the fact that the complete information about the initial state of a quantum field in a collapsing spacetime is not available to future asymptotic observers, belying the expectations from a unitary quantum theory. We study the imprints of the initial quantum state contained in a specific class of distortions of the black hole radiation and identify the classes of in-states which can be partially/fully reconstructed from the information contained within. Even for the general in-state, we can uncover some specific information. These results suggest that a \textit{classical} collapse scenario ignores this richness of information in the resulting spectrum and a consistent quantum treatment of the entire collapse process might allow us to retrieve much more information from the spectrum of the final radiation.