The integral form of supergravity

By using integral forms we derive the superspace action of D = 3,N = 1 su- pergravity as an integral on a supermanifold. The construction is based on target space picture changing operators, here playing the roˆle of Poincar ́e duals to the lower-dimensional spacetime surfaces embedded into the supermanifold. We show how the group geometrical action based on the group manifold approach interpolates between the superspace and the component supergravity actions, thus providing an- other proof of their equivalence.