Another positivity proof and gravitational energy localizations

Two locally positive expressions for the gravitational Hamiltonian, one using four-spinors and the other special orthonormal frames, are reviewed. A new quadratic three-spinor-curvature identity is used to obtain another positive expression for the Hamiltonian and thereby a localization of gravitational energy and positive energy proof. These new results provide a link between the other two methods. Localization and prospects for quasilocalization are discussed.