The Hubble constant
Publications of the Astronomical Society of Australia | Published : 2000
With the completion of the Hubble Space Telescope (HST) Key Project on the Extragalactic Distance Scale, it is interesting to form the dimensionless quantity Hoto by multiplying the Hubble Constant by the age of the Universe. In a matter dominated decelerating Universe with a density exceeding 0 · 26 of the critical value, Hoto < 1; in an accelerating Universe with the same Ωm = 0 · 26, but dominated by vacuum energy with ΩV ≥ 1 - Ωm, Hoto ≥ 1. If the first globular clusters formed 109 years after the Big Bang, then with 95% confidence Hoto = 1 · 0 ± 0 · 3. The classical Einstein-de Sitter cosmological model has Hoto = 2/3.