The superconformal gaugings in three dimensions

We show how three-dimensional superconformal theories for any number N ≤ 8 of supersymmetries can be obtained by taking a conformal limit of the corresponding three-dimensional gauged supergravity models. The superconformal theories are characterized by an embedding tensor that satisfies a linear and quadratic constraint. We analyze these constraints and give the general solutions for all cases. We find new N = 4,5 superconformal theories based on the exceptional Lie superalgebras F(4),G(3) and D(2|1;α). Using the supergravity connection we discuss which massive deformations to expect. As an example we work out the details for the case of N = 6 supersymmetry.