In this chapter it is shown how the introduction of a fundamental constant of
nature with dimensions of acceleration into the theory of gravity makes it
possible to extend gravity in a very consistent manner.Comment: 2012, Extending Cosmology: The Metric Approach, Open Questions in
Cosmology; Review article for an Intech "Open questions in cosmology" book
chapter (19 pages, 3 figures). Available from:
http://www.intechopen.com/books/open-questions-in-cosmology/extending-cosmology-the-metric-approac
