Correlators at large c without information loss

TL;DR

This paper investigates heavy-light correlators in the D1D5 CFT and their gravity duals, showing they are protected and free of spurious singularities even at large central charge, which has implications for black hole microstate information.

Contribution

It demonstrates that certain heavy-light correlators are protected and match between the CFT and gravity descriptions without information loss at large central charge.

Findings

Correlators are determined by protected quantities.

CFT and gravity results agree for these correlators.

Correlators lack spurious singularities at large central charge.

Abstract

We study a simple class of correlators with two heavy and two light operators both in the D1D5 CFT and in the dual AdS$_3 \times S^3 \times T^4$ description. On the CFT side we focus on the free orbifold point and discuss how these correlators decompose in terms of conformal blocks, showing that they are determined by protected quantities. On the gravity side, the heavy states are described by regular, asymptotically AdS$_3 \times S^3 \times T^4$ solutions and the correlators are obtained by studying the wave equation in these backgrounds. We find that the CFT and the gravity results agree and that, even in the large central charge limit, these correlators do not have (Euclidean) spurious singularities. We suggest that this is indeed a general feature of the heavy-light correlators in unitary CFTs, which can be relevant for understanding how information is encoded in black hole microstates.