Higher derivative couplings and massive supergravity in three dimensions

Understand

We develop geometric superspace settings to construct arbitrary higher derivative couplings (including R^n terms) in three-dimensional supergravity theories with N=1,2,3 by realising them as conformal supergravity coupled to certain compensators.

• For all known off-shell supergravity formulations, we construct supersymmetric invariants with up to and including four derivatives.
• As a warming-up exercise, we first give a new and completely geometric derivation of such invariants in N=1 supergravity.
• Upon reduction to components, they agree with those given in arXiv:0907.4658 and arXiv:1005.3952.