The cosmological constant and the problem of the age of the universe

We used a spherically symmetric perturbation model and derived a relation between the average density of galactic halo and its epoch of formation. and hence obtained an estimate for the epoch of formation of our Galaxy, tv. With the age of the Galaxy, tG, represented by the age of its globular clusters, the age of the universe is TG + tv. For flat universe models with Ωλ = 0.0, 0.7 and 0.8, we calculated the compatible range of Hubble's constant. It is shown that if the Hubble constant is as large as 80 kms−1 Mpc, then we may not be able to solve the problem of the age of the universe by introducing the cosmological constant.