Unitary 4-point correlators from classical geometries

TL;DR

This paper calculates specific four-point correlators in the D1D5 CFT at strong coupling, revealing their dependence on moduli and non-decay over time, thus providing insights into the structure of pure states in holographic duals.

Contribution

It derives a general formula for heavy-light four-point correlators in the D1D5 CFT and analyzes their properties for various heavy states, extending previous work on correlator computations.

Findings

Correlators depend non-trivially on CFT moduli.

Correlators do not decay at large Lorentzian times.

Results match expected properties of pure states in a unitary theory.

Abstract

We compute correlators of two heavy and two light operators in the strong coupling and large $c$ limit of the D1D5 CFT which is dual to weakly coupled AdS$_3$ gravity. The light operators have dimension two and are scalar descendants of the chiral primaries considered in arXiv:1705.09250, while the heavy operators belong to an ensemble of Ramond-Ramond ground states. We derive a general expression for these correlators when the heavy states in the ensemble are close to the maximally spinning ground state. For a particular family of heavy states we also provide a result valid for any value of the spin. In all cases we find that the correlators depend non-trivially on the CFT moduli and are not determined by the symmetries of the theory, however they have the properties expected for correlators among pure states in a unitary theory, in particular they do not decay at large Lorentzian times.