ANOTHER POSITIVITY PROOF AND GRAVITATIONAL ENERGY LOCALIZATIONS

Two locally positive expressions for the gravitational Hamiltonian, on e using four-spinors and the other special orthonormal frames, are rev iewed. A new quadratic three-spinor-curvature identity is used to obta in another positive expression for the Hamiltonian and thereby a local ization of gravitational energy and positive energy proof. These new r esults provide a link between the other two methods. Localization and prospects for quasilocalization are discussed.