N=2 moduli of AdS4 vacua: a fine-print study

We analyze the moduli spaces near N=4 supersymmetric AdS₄ vacua of string theory by combining and comparing various approaches: (a) the known exact solutions of Type IIB string theory with localized 5-brane sourcees; (b) the holographically dual 3d quiver gauge theories; (c) gauged supergravity; and (d) the representations of the superconformal algebra osp(4|4|) . Short multiplets containing the marginal N=2 deformations transform in the (2; 0), (0; 2) or (1; 1) representations of the R-symmetry group SU(2) _H × SU(2) _C . The first two are classified by the chiral rings of the Higgs and Coulomb branches, while the latter contain mixed-branch operators. We identify the origin of these moduli in string theory, matching in particular the operators of the chiral rings with open strings on the magnetized 5-brane sources. Our results provide new evidence for the underlying holographic duality. The existence of a large number of bound-state moduli highlights the limitations of effective supergravity.