MAX 4 and MAX 5 Cosmic Microwave Background Anisotropy Measurement Constraints on Open and Flat‐Λ Cold Dark Matter Cosmogonies

Abstract

We account for experimental and observational uncertainties in likelihood analyses of cosmic microwave background (CMB) anisotropy data from the MAX 4 and MAX 5 experiments. These analyses use CMB anisotropy spectra predicted in open and spatially flat Λ cold dark matter cosmogonies. Among the models considered, the combined MAX data set is most consistent with the CMB anisotropy shape in Ω0 ~ 0.1-0.2 open models and less so with that in old (t0 15-16 Gyr, i.e., low-h), high baryon density (ΩB 0.0175 h-2), low-density (Ω0 ~ 0.2-0.4), flat-Λ models. The MAX data alone do not rule out any of the models we consider at the 2 σ level. Model normalizations deduced from the combined MAX data are consistent with those drawn from the UCSB South Pole 1994 data, except for the flat bandpower model for which MAX favors a higher normalization. The combined MAX data normalization for open models with Ω0 ~ 0.1-0.2 is higher than the upper 2 σ value of the DMR normalization. The combined MAX data normalization for old (low-h), high baryon density, low-density flat-Λ models is below the lower 2 σ value of the DMR normalization. Open models with Ω0 ~ 0.4-0.5 are not far from the shape most favored by the MAX data, and for these models, the MAX and DMR normalizations overlap. The MAX and DMR normalizations also overlap for Ω0 = 1 and some higher h, lower ΩB, low-density flat-Λ models.