The cosmological constant and cold dark matter
Abstract
THE cold dark matter (CDM) model^{14} for the formation and distribution of galaxies in a universe with exactly the critical density is theoretically appealing and has proved to be durable, but recent work^{58} suggests that there is more cosmological structure on very large scales (l> 10 h ^{1} Mpc, where h is the Hubble constant H _{0} in units of 100 km s^{1} Mpc^{1}) than simple versions of the CDM theory predict. We argue here that the successes of the CDM theory can be retained and the new observations accommodated in a spatially flat cosmology in which as much as 80% of the critical density is provided by a positive cosmological constant, which is dynamically equivalent to endowing the vacuum with a nonzero energy density. In such a universe, expansion was dominated by CDM until a recent epoch, but is now governed by the cosmological constant. As well as explaining largescale structure, a cosmological constant can account for the lack of fluctuations in the microwave background and the large number of certain kinds of object found at high redshift.
 Publication:

Nature
 Pub Date:
 December 1990
 DOI:
 10.1038/348705a0
 Bibcode:
 1990Natur.348..705E
 Keywords:

 Astronomical Models;
 Cosmology;
 Dark Matter;
 Constants;
 Galaxies;
 Hubble Constant;
 Many Body Problem;
 Relic Radiation;
 Spatial Distribution;
 Astrophysics