Topological parameters in gravity

Understand

We present the Hamiltonian analysis of the theory of gravity based on a Lagrangian density containing Hilbert-Palatini term along with three topological densities, Nieh-Yan, Pontryagin and Euler.

• The addition of these topological terms modifies the symplectic structure non-trivially.
• The resulting canonical theory develops a dependence on three parameters which are coefficients of these terms.
• In the time gauge, we obtain a real SU (2) gauge theoretic description with a set of seven first class constraints corresponding to three SU (2) rotations, three spatial diffeomorphism and one to evolution in a timelike direction.