Einstein–de Sitter universe

Source: Wikipedia, the free encyclopedia.

The Einstein–de Sitter universe is a model of the universe proposed by

spatial curvature as well as a vanishing cosmological constant. In modern parlance, the Einstein–de Sitter universe can be described as a cosmological model for a flat matter-only Friedmann–Lemaître–Robertson–Walker metric (FLRW) universe.[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

Einstein gravitational constant
. The size of the Einstein–de Sitter universe evolves with time as , making its current age 2/3 times the
Hubble time. The Einstein–de Sitter universe became a standard model of the universe for many years because of its simplicity and because of a lack of empirical evidence for either spatial curvature or a cosmological 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, Einstein's later reviews of cosmology make it clear that he saw the model as only one of several possibilities for the expanding universe.[10][11][12]

The Einstein–de Sitter universe was particularly popular in the 1980s, after the theory of

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.

See also

Notes and references

  1. PMID 16587663
    .
  2. PMID 16577160
    .
  3. ^ Einstein, Albert (1931). "Zum kosmologischen Problem der allgemeinen Relativitätstheorie". Sitzungs.König. Preuss. Akad.: 235–237.
  4. S2CID 53419239.Physics ArXiv preprint
  5. ISBN 3-540-43128-4
    .
  6. S2CID 4163892
    .
  7. PMID 16587663
    .
  8. ^ Kragh, Helge (1999). Cosmology and Controversy. New Jersey: Princeton University Press. p. 35.
  9. ^ Nussbaumer, Harry (2009). Discovering the Expanding Universe. Cambridge: Cambridge University Press. pp. 144–152.
  10. ^ Einstein, Albert (1945). The Meaning of Relativity (2nd ed.). New York: Routledge. pp. 112–135.
  11. ^ Einstein, Albert (1933). La Theorie de la Relativité. Paris: Hermann et Cie. pp. 99–109.
  12. S2CID 67804652
    .
Retrieved from "https://en.wikipedia.org/w/index.php?title=Einstein–de_Sitter_universe&oldid=1139922835"