Matter Coupled AdS 3 Supergravities and Their Black Strings

We couple n copies of N = (2, 0) scalar multiplets to a gauged N = (2, 0) supergravity in 2 + 1 dimensions which admits AdS 3 as a vacuum. The scalar fields are charged under the gauged R-symmetry group U (1) and parametrize certain Kahler manifolds with compact or non-compact isometries. The radii of these manifolds are quantized in the compact case, but arbitrary otherwise. In the compact case, we find half-supersymmetry preserving and asymptotically Minkowskian black string solutions. For a particular value of the scalar manifold radius, the solution coincides with that of Horne and Horowitz found in the context of a string theory in 2 + 1 dimensions. In the non-compact case, we find half-supersymmetry preserving and asymptotically AdS 3 string solutions which have naked singularities. We also obtain two distinct AdS 3 supergravities coupled to n copies of N = (1, 0) scalar multiplets either by the truncation of the (2, 0) model or by a direct construction.