Abstract
Using a recent classification of local symmetries of the vacuum Einstein equations, it is shown that there can be no observables for the vacuum gravitational field (in a closed universe) built as spatial integrals of local functions of Cauchy data and their derivatives.
- Received 28 June 1993
DOI:https://doi.org/10.1103/PhysRevD.48.R2373
©1993 American Physical Society
