Max Tegmark's library: 10par

Figure 3: The dark red region is ruled out by CMB alone. The orange red region is ruled out if h=65 +/- 7 and the orange region is as well if the nucleosynthesis constraints on the baryon density are correct. Both an open and a closed Universe is seen to be allowed, but only with a cosmological constant Lambda>0.

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Current cosmological constraints from a 10 parameter CMB analysis


Lambda is alive and well


Max Tegmark, Matias Zaldarriaga


We compute the constraints on a ``standard'' 10 parameter cold dark matter (CDM) model from the most recent CMB and data and other observations, exploring 30 million discrete models and two continuous parameters. Our parameters are the densities of CDM, baryons, neutrinos, vacuum energy and curvature, the reionization optical depth, and the normalization and tilt for both scalar and tensor fluctuations. Our strongest constraints are on spatial curvature, -0.24 < Omega_k < 0.38, and CDM density, h^2 Omega_cdm <0.3, both at 95%. Including SN 1a constraints gives a positive cosmological constant at high significance. We explore the robustness of our results to various assumptions. We find that three different data subsets give qualitatively consistent constraints. Some of the technical issues that have the largest impact are the inclusion of calibration errors, closed models, nucleosynthesis constraints and 10-dimensional likelihood interpolation.

Reference info:

astro-ph/0002091, submitted to ApJ
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