Cosmological Parameters 2000

Abstract

The cosmological parameters that I emphasize are the age of the universe $t_0$, the Hubble parameter $H_0 \equiv 100 h$ km s$^{-1}$ Mpc$^{-1}$, the average matter density $Ω_m$, the baryonic matter density $Ω_b$, the neutrino density $Ω_ν$, and the cosmological constant $Ω_Λ$. The evidence currently favors $t_0 \approx 13$ Gyr, $h \approx 0.65$, $Ω_m \approx 0.4\pm0.1$, $Ω_b = 0.02h^{-2}$, $0.001 < Ω_ν< 0.1$, and $Ω_Λ\approx 0.7$.