The Holographic Dual of AdS3 x S3 x S3 x S1
David Tong
TL;DR
The work identifies a candidate 2D $N=(0,4)$ gauge theory living on the D1-D5-D5' brane intersection and argues it flows to a large $N=(4,4)$ SCFT that holographically corresponds to string theory on $AdS_3\times S_+^3\times S_-^3\times S^1$. Central charge matching between the boundary theory and the supergravity solution provides strong evidence for the duality. The analysis combines detailed D-brane dynamics, ${\cal N}=(0,4)$ multiplet structure, and anomaly-based central charge calculations to support the proposed fixed point. Open questions remain about the interpretation of the r.h.s. geometry, the fate of extra left-moving fermions, and potential connections to higher-spin constructions in AdS$_3$.
Abstract
We construct the two dimensional N=(0,4) gauge theory that lives on the world volume of D1-branes and intersecting D5-branes. We conjecture that this theory flows in the infra-red to a fixed point with large N=(4,4) superconformal symmetry. The central charge of the conformal field theory is shown to coincide with the holographic dual of string theory compactified on AdS3 x S3 x S3 x S1.