A covariant formalism for Chern-Simons gravity

Chern-Simons type Lagrangians in d = 3 dimensions are analysed from the point of view of their covariance and globality. We use the transgression formula to find out a new fully covariant and global Lagrangian for Chern-Simons gravity: the price for establishing globality is hidden in a bimetric (or biconnection) structure. Such a formulation allows us to calculate from a global and simpler viewpoint the energy-momentum complex and the superpotential both for Yang-Mills and gravitational examples.