A physical protocol for observers near the boundary to obtain bulk information in quantum gravity
Chandramouli Chowdhury, Olga Papadoulaki, and Suvrat Raju
SciPost Phys. 10, 106 (2021) · published 17 May 2021
- doi: 10.21468/SciPostPhys.10.5.106
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Abstract
We consider a set of observers who live near the boundary of global AdS, and are allowed to act only with simple low-energy unitaries and make measurements in a small interval of time. The observers are not allowed to leave the near-boundary region. We describe a physical protocol that nevertheless allows these observers to obtain detailed information about the bulk state. This protocol utilizes the leading gravitational back-reaction of a bulk excitation on the metric, and also relies on the entanglement-structure of the vacuum. For low-energy states, we show how the near-boundary observers can use this protocol to completely identify the bulk state. We explain why the protocol fails completely in theories without gravity, including non-gravitational gauge theories. This provides perturbative evidence for the claim that one of the signatures of holography --- the fact that information about the bulk is also available near the boundary --- is already visible in the low-energy theory of gravity.
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Authors / Affiliations: mappings to Contributors and Organizations
See all Organizations.- 1 टाटा मूलभूत अनुसंधान संस्थान / Tata Institute of Fundamental Research [TIFR]
- 2 International Centre for Theoretical Sciences [ICTS-TIFR]
- Department of Science and Technology, Ministry of Science and Technology (through Organization: विज्ञान एवं प्रौद्योगिकी विभाग / Department of Science and Technology [DST])