The universality of the Wheeler-DeWitt equation

Accelerated Expansion from Negative Λ

We show for a wide class of models with non-zero cosmological constant that solutions of the wheeler-de witt equation exhibit a universal semiclassical asymptotic structure for large spatial volumes.A consequence of this asymptotic structure is that a wave function in a gravitational theory with a negative cosmologicalconstant can predict an ensemble of asymptotically classical histories which expand with a positive effective cosmological constant.This raises the possibility that even fundamental theories with a negative cosmologicalconstant can be consistent with our low-energy observations of a classical, accelerating universe.We illustrate this general framework with the specific example of the no-boundary wave function in its holographic form.Implications of these results for model building in string cosmology are discussed.