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<=τ_c<=0.4, we find that the total density of the universe Ω_tot=1.04+/-0.06 and the spectral index of the initial scalar fluctuations n_s=1.01^+0.08_-0.06 in accordance with the predictions of inflationary theory. In addition, we find that the physical density of baryons Ω_bh²=0.022^+0.004_{- 0.003}, and the physical density of cold dark matter Ω_cdmh²=0.14+/-0.04. This value of Ω_bh² 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 find that Ω_tot=1.00+/-0.04, the matter density Ω_m=0.40+/-0.15, and the vacuum energy density Ω_Λ=0.60+/-0.15. (All 68% confidence limits.)