Exceptional N=6 and N=2 AdS4 supergravity, and zero-center modules

We study the gauging of the orthosymplectic algebras OSp(6 vertical bar 4) x SO(2) and its dual OSp(2 vertical bar 4) x SO(6), both based on supergravities with the same exceptional coset SO*(12)/U(6), and gauge group SO(6) x SO(2). The two dual theories are obtained by two different truncations of gauged N = 8 AdS(4) supergravity. We explicitly study the gauge sector of the two dual theories with the most general group allowed by supersymmetry. The N = 6 gravity multiplet has also the exceptional property to be a zero-center module of OSp(6 vertical bar 4), as it is the case for superconformal Yang-Mills theory in four dimensions based on SU(2, 2 vertical bar n) ( PSU(2, 2 vertical bar 4) for n = 4) or OSp(n vertical bar 4).