Kaluza - Klein supergravity on AdS 3 × S 3

We construct a Chern-Simons type gauged N = 8 supergravity in three spacetime dimensions with gauge group SO(4) × T∞ over the infinite dimensional coset space SO(8,∞)/ (SO(8)× SO(∞)), where T∞ is an infinite dimensional translation subgroup of SO(8,∞). This theory describes the effective interactions of the (infinitely many) supermultiplets contained in the two spin-1 Kaluza-Klein towers arising in the compactification of N = (2, 0) supergravity in six dimensions on AdS3 × S 3 with the massless supergravity multiplet. After the elimination of the gauge fields associated with T∞, one is left with an Yang Mills type gauged supergravity with gauge group SO(4), and in the vacuum the symmetry is broken to the (super-)isometry group of AdS3 × S 3, with infinitely many fields acquiring masses by a variant of the Brout-Englert-Higgs effect. [email protected] [email protected]