A recent anisotropy experiment with a 30’ beam is close to optimal for testing models in which cosmic structure arose from inflation-generated Gaussian density perturbations. Using a Bayesian analysis to constrain the amplitude of the perturbation spectrum, we show that adiabatic hot-dark-matter models are convincingly ruled out and cold-dark-matter models have anisotropies near our derived limits. Theories with broken scale invariance such as isocurvature baryon models are strongly constrained, as are models with extra power crafted to give significant large-scale structures and flows.

• Received 21 December 1990

DOI:https://doi.org/10.1103/PhysRevLett.66.2179