AdS/CFT duality and the black hole information paradox
Oleg Lunin, Samir D. Mathur
TL;DR
The paper investigates the AdS/CFT correspondence in the D1-D5 system, focusing on Ramond-sector ground states and their dual throat geometries. It demonstrates a precise CFT–supergravity match below the black-hole threshold, including identical time delays and emission rates, and shows how throat endings, dictated by microstate structure, encode information about the CFT state. It argues that semiclassical gravity can break down when multiple excitations populate a single component string, offering a concrete link to a proposed information-paradox resolution via the stretching of spacelike slices and a density-of-degrees-of-freedom argument. By mapping D1-D5 states to FP configurations and exploring hair, singularities, and generic j configurations, the work provides a unified microscopic–macroscopic picture connecting microstate geometries to information retrieval while clarifying the limits of the semiclassical approximation. Overall, the results suggest that information leakage in Hawking radiation can be realized within a unitary, string-theoretic framework without invoking nonlocal physics beyond holography.
Abstract
Near-extremal black holes are obtained by exciting the Ramond sector of the D1-D5 CFT, where the ground state is highly degenerate. We find that the dual geometries for these ground states have throats that end in a way that is characterized by the CFT state. Below the black hole threshold we find a detailed agreement between propagation in the throat and excitations of the CFT. We study the breakdown of the semiclassical approximation and relate the results to the proposal of gr-qc/0007011 for resolving the information paradox: semiclassical evolution breaks down if hypersurfaces stretch too much during an evolution. We find that a volume V stretches to a maximum throat depth of V/2G.
