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Cosmic Microwave Background Anisotropy Constraints on Open and Flat‐Λ Cold Dark Matter Cosmogonies from UCSB South Pole, ARGO, MAX, White Dish, and SuZIE Data

1999; IOP Publishing; Volume: 517; Issue: 2 Linguagem: Inglês

10.1086/307236

1538-4357

Bharat Ratra, Radosław Stompor, K. Ganga, G. Rocha, Naoshi Sugiyama, K. M. Górski,

Dark Matter and Cosmic Phenomena

We use combinations of 10 small-scale cosmic microwave background anisotropy data sets from the UCSB South Pole 1994, ARGO, MAX 4 and 5, White Dish, and SuZIE experiments to constrain cosmogonies. We consider open and spatially flat-Λ cold dark matter cosmogonies with nonrelativistic mass density parameter Ω0 in the range 0.1-1, baryonic mass density parameter ΩB in the range 0.005-0.029 h-2, and age of the universe t0 in the range 10-20 Gyr. Marginalizing over all parameters but Ω0, the combined data favor a Ω0≃1 (1) open (flat-Λ) model. Excluding the smallest angular scale SuZIE data, an Ω0≃0.3 (1) open (flat-Λ) model is favored. Considering only multifrequency data with error bars consistent with sample variance and noise considerations, i.e., the South Pole 1994 Ka band, the MAX 4 ι Draconis, and the MAX 5 HR5127 data, an Ω0≃0.1 (1) open (flat-Λ) model is favored. For both open and flat-Λ models and for all three combinations of data sets, after marginalizing over all other parameters, a lower ΩBh2 (~0.005) or younger (t0~10 Gyr) universe is favored. However, the data do not rule out other values of Ω0 in the flat-Λ model and other values of ΩBh2 in both models. At 2 σ confidence, model normalizations deduced from the small-scale data are consistent with those derived from the Differential Microwave Radiometer data. We emphasize that since we consider only a small number of data sets, these results are tentative.