Recovering the effective cosmological constant in extended gravity theories

Capozziello, S.; de Ritis, R.; Marino, A. A.

Recovering the effective cosmological constant in extended gravity theories

Authors

Capozziello, S.

de Ritis, R.

Marino, A. A.

Description

In the framework of extended gravity theories, we discuss the meaning of a time dependent "cosmological constant" and give a set of conditions to recover asymptotic de Sitter behaviour for a class of cosmological models independently of initial data. To this purpose we introduce a time-dependent (effective) quantity which asymptotically becomes the true cosmological constant. We will deal with scalar-tensor, fourth and higher than fourth-order theories.
24 pages, Latex, submitted to Gen.Rel.and Grav