We clarify the higher-dimensional origin of a class of dyonic gaugings of D = 4 N = 8 supergravity recently discovered, when the gauge group is chosen to be ISO(7). This dyonically-gauged maximal supergravity arises from consistent truncation of massive IIA supergravity on S 6 , and its magnetic coupling constant descends directly from the Romans mass. The critical points of the supergravity uplift to new AdS4 massive type IIA vacua. We identify the corresponding CFT3 duals as superChern-Simons-matter theories with simple gauge group SU(N ) and level k given by the Romans mass. In particular, we find a critical point that uplifts to the first explicit N = 2 AdS4 massive IIA background. We compute its free energy and that of the candidate dual Chern-Simons theory by localisation to a solvable matrix model, and find perfect agreement. This provides the first AdS4/CFT3 precision match in massive type IIA string theory.

Motivated by its well defined higher dimensional origin, a detailed study of D = 4 N = 8 supergravity with a dyonically gauged ISO(7) = SO(7) R 7 gauge group is performed. We write down the Lagrangian and describe the tensor and duality hierarchies, focusing on an interesting subsector with closed field equations and supersymmetry transformations. We then truncate the N = 8 theory to some smaller sectors with N = 2 and N = 1 supersymmetry and SU(3), G 2 and SO(4) bosonic symmetry. Canonical and superpotential formulations for these sectors are given, and their vacuum structure and spectra is analysed. Unlike the purely electric ISO(7) gauging, the dyonic gauging displays a rich structure of vacua, all of them AdS. We recover all previously known ones and find a new N = 1 vacuum with SU(3) symmetry and various non-supersymmetric vacua, all of them stable within the full N = 8 theory.

We analyse the vacuum structure of isotropic Z 2 × Z 2 flux compactifications, allowing for a single set of sources. Combining algebraic geometry with supergravity techniques, we are able to classify all vacua for both type IIA and IIB backgrounds with arbitrary gauge and geometric fluxes. Surprisingly, geometric IIA compactifications lead to a unique theory with four different vacua. In this case we also perform the general analysis allowing for sources compatible with minimal supersymmetry. Moreover, some relevant examples of type IIB non-geometric compactifications are studied. The computation of the full N = 4 mass spectrum reveals the presence of a number of non-supersymmetric and nevertheless stable AdS 4 vacua. In addition we find a novel dS 4 solution based on a non-semisimple gauging.

Multi-parametric families of AdS 4 vacua with various amounts of supersymmetry and residual gauge symmetry are found in the [SO(1, 1) × SO(6)] ⋉ R 12 maximal supergravity that arises from the reduction of type IIB supergravity on R × S 5 . These provide natural candidates to holographically describe new strongly coupled three-dimensional CFT's which are localised on interfaces of N = 4 super-Yang-Mills theory. One such AdS 4 vacua features a symmetry enhancement to SU(2) × U(1) while preserving N = 2 supersymmetry. Fetching techniques from the E 7(7) exceptional field theory, its uplift to a class of N = 2 S-folds of type IIB supergravity of the form AdS 4 × S 1 × S 5 involving S-duality twists of hyperbolic type along S 1 is presented.

We perform an exhaustive classification of G2 invariant extrema of the most general gauged N = 8 supergravity in four dimensions. They comprise four branches of Anti-de Sitter solutions labelled by a single parameter. Interestingly, while the gauge groups vary with the parameters, the mass spectra are invariant. One of these is a new non-supersymmetric yet stable point. Our analysis includes the recently proposed family of SO(8) gauged supergravities and more.