Generalized gravitational S-duality and the cosmological constant problem

Abstract

We study S-duality transformations that mix the Riemann tensor with the field strength of a 3-form field. The dual of an (A)dS spacetime—with arbitrary curvature—is seen to be flat Minkowski spacetime if the 3-form field has vanishing field strength before the duality transformation. It is discussed whether matter could couple to the dual metric, related to the Riemann tensor after a duality transformation. This possibility is supported by the facts that the Schwarzschild metric can be obtained as a suitable contraction of the dual of a Taub-NUT-AdS metric, and that metrics describing FRW cosmologies can be obtained as duals of theories with matter in the form of torsion.