Abstract

We present the maximally supersymmetric three-dimensional gauged supergravities. Owing to the special properties of three dimensions — especially the on-shell duality between vector and scalar fields, and the purely topological character of (super)gravity — they exhibit an even richer structure than the gauged supergravities in higher dimensions. The allowed gauge groups are subgroups of the global E 8(8) symmetry of ungauged N = 16 supergravity. They include the regular series SO(p, 8 −p) ×SO(p, 8 −p) for all p = 0, 1,..., 4, the group E 8(8) itself, as well as various noncompact forms of the exceptional groups E7, E6 and F4 × G2. We show that all these theories admit maximally supersymmetric ground states, and determine their background isometries, which are superextensions of the anti-de Sitter group SO(2, 2). The very existence of these theories is argued to point to a new supergravity beyond the standard D=11 supergravity.