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.