Abstract

A Chern-Simons action for supergravity in odd-dimensional spacetimes is proposed. For all odd dimensions, the local symmetry group is a nontrivial supersymmetric extension of the Poincare group. In 2 + 1 dimensions the gauge group reduces to super-Poincare, while for D = 5 it is super-Poincare with a central charge. In general, the extension is obtained by the addition of a one-form field which transforms as an antisymmetric fifth-rank tensor under Lorentz rotations. Since the Lagrangian is a Chern-Simons density for the supergroup, the supersymmetry algebra closes off shell without the need of auxiliary fields.