Dynamical adjustment of the cosmological constant

Abstract

We examine a recent proposal by Peccei, Sola and Wetterich for the dynamical cancellation of the cosmological constant and explicitly demonstrate that their mechanism is plagued by a fine-tuning problem, order-by-order in perturbation theory. Our analysis, however, suggests a modification of their scheme which seems to have a good chance of solving the cosmological constant problem. It involves the existence of more than one dilaton. We also discuss the relevance to “fifth” forces.