The “Sandwich Conjectyre” (SC) was originally formulated by Wheeler and his coworkers.1 In the course of several years both the original author(s) and others have proposed the statement in several different forms, and with different qualifications. Roughly, the SC asserts that in a purely gravitational field the internal geometries of two distinct three-dimensional space-like hypersurfaces determine uniquely the geometry of a four-dimensional space-time (i.e. pseudo-Riemannian) manifold that is required to obey Einstein’s field equations (i.e. to be Ricci-flat). In a careful formulation one will have to specify further whether the two three-surfaces are to be “close together”, whether the distance between them is to be given as additional data, and what sort of conditions are to be imposed at space-like infinity.
KeywordsPhase Space Equivalence Class Configuration Space Canonical Variable Einstein Manifold
Unable to display preview. Download preview PDF.