Recovering information in an asymptotically flat spacetime in quantum gravity

As an extension of Chowdhury et al (2021 SciPost Phys. 10 106) and Laddha et al (2021 SciPost Phys. 10 041) we present a physical protocol that a set of observers can use to detect a pure state in the bulk when they are spread across a small cut near in flat spacetime. The protocol involves the modification of a bulk state using simple unitary operators and measurements of the energy of the state. The states that we study are constructed by acting with low energy operators on a vacuum state such that a perturbative analysis is valid. We restrict ourselves to 3 + 1 dimensional spacetimes and only consider massless excitations. From this analysis, the principle of holography of information becomes manifest in the case of asymptotically flat spacetime.