 Nester two-form

This antisymmetric spinor bilinear converts the positive energy theorem into a boundary-charge identity. Its divergence is $2({\nabla }_{\nu }\overline{ϵ}){\gamma }^{\mu \nu \rho }{\nabla }_{\rho }ϵ+G^{\mu \nu }\overline{ϵ}{\gamma }_{\nu }ϵ$ in the mostly-plus conventions specified here. On a spacelike hypersurface the first term is twice the difference between the squared spatial covariant derivative and the squared spatial Dirac operator. The Witten spinor equation removes the negative square, while the dominant energy condition controls the curvature term through the Einstein constraints.