  We show how to implement T-duality along non-abelian isometries in
backgrounds with non-vanishing Ramond fields. When the dimension of the
isometry group is odd (even) the duality swaps (preserves) the chirality of the
theory. In certain cases a non-abelian duality can result in a massive type-IIA
background. We provide two examples by dualising SU(2) isometry subgroups in
$AdS_5\times S^5$ and $AdS_3\times S^3\times T^4$. The resultant dual
geometries inherit the original AdS factors but have transverse spaces with
reduced isometry and preserve only half of the original supersymmetry. The
non-abelian dual of $AdS_5\times S^5$ has an M-theory lift which is related to
the gravity duals of N=2 superconformal theories. We comment on a possible
interpretation of this as a high spin limit.

High Energy Physics - Theory