TOWARD AN OFF-SHELL 11D SUPERGRAVITY LIMIT OF M-THEORY

We demonstrate that in addition to the usual fourth-rank superfield (W -abcd) which describes the on-shell theory, a spinor superfield (J(alp ha)) can be introduced into the 11D geometrical tensors with engineeri ng dimensions less or equal to one in such a way to satisfy the Bianch i identities in superspace. The components arising from J(alpha) are i dentified as some of the auxiliary fields required for a full off-shel l formulation. Our result indicates that eleven-dimensional supergravi ty does not have to be completely on-shell. The kappa-symmetry of the supermembrane action in the presence of our partial off-shell supergra vity background is also confirmed. Our modifications to eleven-dimensi onal supergravity theory are thus Likely relevant for M-theory. We sug gest our proposal as a significant systematic off-shell generalization of eleven-dimensional supergravity theory.