[5][6][7] In the model, Einstein and de Sitter derived a simple relation between the average density of matter in the universe and its expansion according to H02 = кρ/3, where H0 is the Hubble constant, ρ is the average density of matter and к is the Einstein gravitational constant.
[8][9] It also represented an important theoretical case of a universe of critical matter density poised just at the limit of eventually contracting.
However, in the 1990s various observations including galaxy clustering and measurements of the Hubble constant led to increasingly serious problems for this model.
Following the discovery of the accelerating universe in 1998, and observations of the cosmic microwave background and galaxy redshift surveys in 2000–2003, it is now generally accepted that dark energy makes up around 70 percent of the present energy density while cold dark matter contributes around 25 percent, as in the modern Lambda-CDM model.
The Einstein–de Sitter model remains a good approximation to our universe in the past at redshifts between around 300 and 2, i.e. well after the radiation-dominated era but before dark energy became important.