1998/03/23 by Ruth A. Daly, Daly, Ruth A., E. J. Guerra +3
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics (astro-ph) #Cosmology and Gravitation Theories #FOS: Physical sciences #Relativity and Gravitational Theory #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9803265
To appear in "Fundamental Parameters in Cosmology", The proceedings of the XXXIIIrd Rencontres de Moriond, eds. J. Trân Thanh Vân & Y. Giraud-Heraud, (Paris, France: Editions Frontieres)
arxiv created 1998/03/23 · openalex publication_date 1998/03/23 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Fourteen classical double radio galaxies with redshifts between zero and two were used to determine the cosmological parameters Ωm, ΩΛ, and Ωk, where these are the normalized values of the mean mass density, cosmological constant, and space curvature at the present epoch. A low value of Ωm is obtained, and Ωm = 1 is ruled out with 97.5% confidence. The low value of Ωm determined using the radio source method described here is also indicated by several independent tests. Thus, it appears that either a cosmological constant, or space curvature, is significant at the present epoch. This means that the universe is undergoing, or has recently undergone, a transition away from a state of matter domination and into a state where either a cosmological constant or space curvature is determining the expansion rate of the universe. The low value of Ωm presented here and by Guerra & Daly (1998) means that we can state with 97.5 % confidence that the universe will continue to expand forever.