The Wald-Zoupas prescription for asymptotic charges at null infinity in general relativity.

We use the formalism developed by Wald and Zoupas to derive explicit covariant expressions for the charges and fluxes associated with the Bondi-Metzner-Sachs symmetries at null infinity in asymptotically flat spacetimes in vacuum general relativity. Our expressions hold in non-stationary regions of null infinity, are local and covariant, conformally-invariant, and are independent of the choice of foliation of null infinity and of the chosen extension of the symmetries away from null infinity. We also include detailed comparisons with other expressions for the charges and fluxes that have appeared in the literature, including expressions in conformal Bondi-Sachs coordinates, the Ashtekar-Streubel flux formula, the Komar formulae and the linkage and twistor charge formulae.