The mean mass density of the Universe
Abstract
Observations of galaxy clustering indicate that the mean mass density is only about onethird of that predicted by the popular Einsteinde Sitter cosmological model. Theory and observation can be reconciled if there has been largescale segregation of galaxies from mass, but the gravitational instability of the expanding universe would tend to destroy such a segregation. Thus either conventional ideas about galaxy formation are wrong, or the Einsteinde Sitter model is not a useful approximation.
 Publication:

Nature
 Pub Date:
 May 1986
 DOI:
 10.1038/321027a0
 Bibcode:
 1986Natur.321...27P
 Keywords:

 Astronomical Models;
 Density Distribution;
 Mass Distribution;
 Space Density;
 Universe;
 Big Bang Cosmology;
 Galactic Clusters;
 Gravitational Fields;
 Astrophysics