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

Abstract

Three peaks and two dips have been detected in the power spectrum of the cosmic microwave background from the BOOMERANG experiment, at ℓ ∼ 210, 540, 840 and ℓ ∼ 420, 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: Ω tot = 1.02 +0.06 −0.05 vs. 1.04±0.05, Ω b h 2 = 0.022 +0.004 −0.003 vs. 0.019 +0.005 −0.004 , and n s = 0.96 +0.10 −0.09 vs. 0.90±0.08. The deviation in primordial spectral index n s is a consequence of the strong correlation with the optical depth.

The Anisotropy of the Microwave Background tol= 3500: Mosaic Observations with the Cosmic Background Imager

“…10) suggest the presence of peaks and dips, but, as a result of the anticorrelations between adjacent bins, their reality is difficult to assess in this presentation or in similar plots of the Dl ¼ 140 bins. To assess their significance, we have searched for extrema in the power spectrum following techniques applied to the BOOMERANG data by de Bernardis et al (2002). For each triplet of adjacent bins (i À 1, i, i þ 1) we model the local band power profile as a three-parameter quadratic form…”

“…A second approach to peak/dip detection was also used by de Bernardis et al (2002): given a class of theoretical models with a sequence of peaks and dips, the statistical distribution of positions and amplitudes can be predicted by ensemble averaging over the full probability, the multidimensional likelihood. We have used the same C l database as de Bernardis et al (2002).…”

“…We have used the same C l database as de Bernardis et al (2002). Figure 15 shows the peaks and dips we '' predict '' from BOOMERANG, DASI, MAXIMA, COBE DMR, and 19 other experiments predating this CBI data set.…”

Testing for foreground residuals in thePlanckforeground cleaned maps: A new method for designing confidence masks

“…A plethora of phenomena are explained by the best-fit ΛCDM model, which complies with the cosmological principles of homogeneity and isotropy. For over a decade it has withstood serious challenges brought forth by comparison with high-precision data delivered by the WMAP satellite (Bennett et al 2003(Bennett et al , 2013Hinshaw et al 2007Hinshaw et al , 2009Jarosik et al 2011), not to mention other numerous experiments, such as BOOMERanG (de Bernardis et al 2002), MAXIMA (Lee et al 2001), DASI (Halverson et al 2002), ACBAR (Kuo et al 2007), and others.…”

An optimal basis system for cosmology: data analysis and new parameterisation

“…Eisenstein et al 2005), the cosmic microwave background (CMB) power spectrum (e.g. de Bernardis et al 2002;Komatsu et al 2009), and the cosmic shear correlation function (e.g. Benjamin et al 2007;Fu et al 2008), etc.…”