The dynamical parameters describing the cosmic expansion are still very inaccurately known, permitting a wide range of cosmological models to appear plausible. Judging from all the information available at present, the Universe is either open, with the total density parameter or flat by virtual of the presence of a cosmological constant. Let us use the notation
where the density parameter of the vacuum energy is , and is the density parameter of baryonic + dark matter.
We study here whether the "standard model" of flat space with is still viable in the light of recent determinations of several cosmological parameters.
© European Southern Observatory (ESO) 1998
Online publication: November 24, 1997