Résumé:

After a brief review of unusual features of the light front canonical formulations of field theories, I'll present the analysis of the canonical structure of the first order formulation of general relativity on a lightlike foliation. It appears to be quite different from the usual spacelike case leading, for instance, to the presence of tertiary constraints. Besides, I'll discuss the issue of the zero modes and argue that there might be some hidden correspondence with two-dimensional theories.