Multiple Peaks in the Angular Power Spectrum of the Cosmic Microwave Background: Significance and Consequences for Cosmology

Three peaks and two dips have been detected in the power spectrum of the cosmic microwave background from the BOOMERANG experiment, at l=(213+10/- 13),(541+20/-32),(845+12/-25) and l=(416+22/-12), (750+20/750) respectively. Using model-independent analyses, we find that all five features are statistically significant and we measure their location and amplitude. These are consistent with the adiabatic inflationary model. We also calculate the mean and variance of the peak and dip locations and amplitudes in a large 7-dimensional parameter space of such models, which gives good agreement with the model-independent estimates, and forecast where the next few peaks and dips should be found if the basic paradigm is correct. We test the robustness of our results by comparing Bayesian marginalization techniques on this space with likelihood maximization techniques applied to a second 7-dimensional cosmological parameter space, using an independent computational pipeline, and find excellent agreement: Omega 1.02 +0.06/-0.05 versus 1.04 ++0.05/-0.05, Omega_b.h^2=0.022+0.004/- 0.003 versus 0.019(+0.005/-0.004) and n_s =0.96{+0.09/-0.08)versus 0.90 (+0.08/-0.08). The determination of thr best fit by the maximization procedure effectively igrores nonzero optical depth of reionization Tau_c >0 and the difference in primordial spectral index n_s between the two methods is thus is a consequence of the strong correlation of n_s with the Tau_c