Cosmological Parameters 2000

The cosmological parameters that I emphasize are the age of the universe $t_0$, the Hubble parameter $H_0\equiv 100h$ km s${}^{-1}$ Mpc${}^{-1}$, the average matter density ${\mathrm{\Omega }}_m$, the baryonic matter density ${\mathrm{\Omega }}_b$, the neutrino density ${\mathrm{\Omega }}_{\nu }$, and the cosmological constant ${\mathrm{\Omega }}_{\mathrm{\Lambda }}$. The evidence currently favors $t_0\approx 13$ Gyr, $h\approx 0.65$, $\Omega_m \approx 0.4\pm0.1$,$\Omega_b = 0.02h^{-2}$,$0.001 < \Omega_\nu < 0.1$,and$\Omega_\Lambda \approx 0.7$.