Abstract
We propose a description of dark energy and acceleration of the universe in extended supergravities with de Sitter (dS) solutions. Some of them are related to M theory with noncompact internal spaces. Masses of ultralight scalars in these models are quantized in units of the Hubble constant: If the dS solution corresponds to a minimum of the effective potential, the universe eventually becomes dS space. If the dS solution corresponds to a maximum or a saddle point, which is the case in all known models based on supergravity, the flat universe eventually stops accelerating and collapses to a singularity. We show that in these models, as well as in the simplest models of dark energy based on supergravity, the typical time remaining before the global collapse is comparable to the present age of the universe, We discuss the possibility of distinguishing between various models and finding our destiny using cosmological observations.
- Received 30 August 2002
DOI:https://doi.org/10.1103/PhysRevD.66.123503
©2002 American Physical Society