2001 (IPP)

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Binned cosmic microwave background anisotropy power spectra : Peak location
(2001-02-15) Podariu, Silviu; Souradeep, Tarun; Gott, J. Richard; et al.
We use weighted mean and median statistics techniques to combine individual cosmic microwave background (CMB) anisotropy detections and determine binned, multipole- space, CMB anisotropy power spectra. The resultant power spectra are peaked. The derived weighted-mean CMB anisotropy power spectrum is not a good representation of the individual measurements in a number of multipole-space bins, if the CMB anisotropy is Gaussian and correlations between individual measurements are small. This could mean that some observational error bars are underestimated, possibly as a consequence of undetected systematic eﬀects. Discarding the most discrepant 5% of the measure- ments alleviates but does not completely resolve this problem. The median-statistics power spectrum of this culled data set is not as constraining as the weighted-mean power spectrum. Nevertheless it indicates that there is more power at multipoles ℓ ∼ 150 − 250 than is expected in an open cold dark matter (CDM) model, and it is more consistent with a ﬂat CDM model. Unlike the weighted-mean power spectrum, the median-statistics power spectrum at ℓ ∼ 400 − 500 does not exclude a second peak in the ﬂat CDM model.