Some aspects of the cosmological conformal equivalence between ``Jordan Frame'' and ``Einstein Frame''

Abstract

The conformal equivalence between Jordan frame and Einstein frame can be used in order to search for exact solutions in general theories of gravity in which scalar fields are minimally or nonminimally coupled with geometry. In the cosmological arena a relevant role is played by the time parameter in which dynamics is described. In this paper we discuss such issues considering also if cosmological Noether symmetries in the ``point--like'' Lagrangian are conformally preserved. Through this analysis and through also a careful analysis of the cosmological parameters Ωand Λ, it is possible to contribute to the discussion on which is the physical system.