Monte Carlo Simulations of Medium - Scale CMB Anisotropy

Recent detections of cosmic microwave background (CMB) anisotropy at half-degree angular scales show considerable scatter in the reported amplitude even at similar angular resolution. We use Monte Carlo techniques to simulate the current set of medium-scale CMB observations, including all relevant aspects of sky coverage and measurement technique. The scatter in the reported amplitudes is well within the range expected for the standard cold dark matter (CDM) cosmological model, and results primarily from the restricted sky coverage of each experiment. Within the context of standard CDM current observations of CMB anisotropy support the detection of a " Doppler peak " in the CMB power spectrum consistent with baryon density 0.01<Ω b <0.13 (95% confidence) for Hubble constant H 0 = 50 km s −1 Mpc −1. The uncertainties are approximately evenly divided between instrument noise and cosmic variance arising from the limited sky coverage.