Conformal actions in any dimension
  Biconformal gauging of the conformal group has a scale-invariant volume form, permitting a single form of the action to be invariant in any dimension. We display several 2n-dim scale-invariant polynomial actions and a dual action. We solve the field equations for the most general action linear in the curvatures for a minimal torsion geometry. In any dimension n>2, the solution is foliated by equivalent n-dim Ricci-flat Riemannian spacetimes, and the full 2n-dim space is symplectic. Two fields defined entirely on the Riemannian submanifolds completely determine the solution: a metric, and a symmetric tensor. 
A. Wehner (Utah State University) and J.T. Wheeler (Utah State   University)