The age of the universe is investigated from a view-point of the primordial nucleosynthesis in the Brans-Dicke model with a varying Λ term. It is shown that the age can be long enough compared with that of the globular clusters using two critical quantities recently reported from the HST observations: the Hubble constant, and deuterium abundances. Then it is shown that the present rate of variation in the gravitational "constant" can be predicted. From the observational constraint in the primordial nucleosynthesis, the baryon density relative to the critical density is found to be Ωb = 0.047-0.14 from the observation by Songaila et al. (1996) and Ωb = 0.16-0.22 from that by Tytler et al. (1996), where the critical density is pc = 6.0 × 10-30 g cm-3 for H0 = 80 km s-1 Mpc-1 and a parameter characteristic to the Brans-Dicke theory. It is concluded that most of the matter consists of the non-baryonic dark matter if the universe is flat.
|ジャーナル||Astronomy and Astrophysics|
|出版ステータス||出版済み - 12 1 1997|
All Science Journal Classification (ASJC) codes