Cosmological parameter extraction from the first season of observations with the Degree Angular Scale Interferometer

The Degree Angular Scale Interferometer (DASI) has measured the power spectrum of the cosmic microwave background anisotropy over the range of spherical harmonic multipoles 100 < l < 900. We compare these data, in combination with the COBE DMR results, to a seven-dimensional grid of adiabatic cold dark matter (CDM) models. Adopting the priors h > 0.45 and 0.0 less than or equal to tauc less than or equal to 0.4, we find that the total density of the universe Omega(tot) = 1.04 +/- 0.06 and the spectral index of the initial scalar fluctuations n(s) = 1.01(-0.06)(+0.08) 0 : 06 in accordance with the predictions of inflationary theory. In addition, we find that the physical density of baryons Omega(b)h(2) = 0.022(-0.003)(+0.004), and the physical density of cold dark matter Omega(cdm) h(2) = 0.14 +/- 0.04. This value of Omega(b)h(2) is consistent with that derived from measurements of the primeval deuterium abundance combined with big bang nucleosynthesis theory. Using the result of the Hubble Space Telescope (HST) Key Project, h = 0.72 +/- 0.08, we nd that Omega(tot) = 1.00 +/- 0.04, the matter density Omega(m) = 0.40 +/- 0.15, and the vacuum energy density Omega(Lambda) = 0.60 +/- 0.15. (All 68% confidence limits.