Multi-Time Measurements in Hawking Radiation: Information at Higher-Order Correlations

TL;DR

This paper introduces a method to evaluate multi-time correlations in Hawking radiation, revealing complex dependencies that suggest potential information storage beyond single-time analyses, challenging previous assumptions about information loss.

Contribution

It develops a novel approach for calculating multi-time correlations in Hawking radiation, uncovering their non-trivial structure and implications for information retention.

Findings

Multi-time correlations depend on angular variables and scattering history.

Correlations are highly non-trivial and richer than single-time correlations.

Potential for storing pre-collapse information in multi-time correlations.

Abstract

It is believed that no information can be stored in Hawking radiation, because correlations between quanta of different field modes vanish. However, such correlations have been defined only with reference to a single moment of time. In this article, we develop a method for the evaluation of {\em multi-time} correlations. We find that these correlations are highly non-trivial: for a scalar field in the Schwarzschild black hole, multi-time correlations have an explicit dependence on angular variables and on the scattering history of Hawking quanta. This result leads us to the conjecture that some pre-collapse information can be stored in multi-time correlations after backreaction effects have been incorporated in the physical description.