From a covariant Hamiltonian formulation, using symplectic ideas, we obtain covariant quasilocal energy-momentum boundary expressions for general gravity theories. The expressions depend on which variables are fixed on the boundary, on a reference configuration and a displacement vector field. We consider applications to Einstein's theory, black hole thermodynamics and alternate spinor expressions. © 1995.
Chen, C. M., Nester, J. M., & Tung, R. S. (1995). Quasilocal energy-momentum for geometric gravity theories. Physics Letters A, 203(1), 5–11. https://doi.org/10.1016/0375-9601(95)92844-T