Global Cosmological Parameters Measured Using Classical Double Radio Sources
Abstract
Fourteen classical double radio galaxies with redshifts between zero and two were used to determine the cosmological parameters $\Omega_m$, $\Omega_{\Lambda}$, and $\Omega_k$, where these are the normalized values of the mean mass density, cosmological constant, and space curvature at the present epoch. A low value of $\Omega_m$ is obtained, and $\Omega_m = 1$ is ruled out with 97.5% confidence. The low value of $\Omega_m$ 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 $\Omega_m$ presented here and by Guerra & Daly (1998) means that we can state with 97.5 % confidence that the universe will continue to expand forever.
 Publication:

arXiv eprints
 Pub Date:
 March 1998
 DOI:
 10.48550/arXiv.astroph/9803265
 arXiv:
 arXiv:astroph/9803265
 Bibcode:
 1998astro.ph..3265D
 Keywords:

 Astrophysics
 EPrint:
 To appear in "Fundamental Parameters in Cosmology", The proceedings of the XXXIIIrd Rencontres de Moriond, eds. J. Tr\^an Thanh V\^an &