Revisiting the oscillations in the cosmic microwave background angular power spectra at ℓ ∼ 120 in the Planck 2015 data

Abstract

While the observed nearly scale-invariant initial power spectrum is regarded as favorable evidence of the standard inflationary cosmology, precision observations of the cosmic microwave background anisotropies also suggest possible existence of nontrivial features such as those observed around multipoles ℓ∼120 by WMAP. Here, we examine the Planck data and investigate the effects of these features on cosmological parameter estimation by performing Markov-chain Monte Carlo analysis. We find that the features exist in the Planck data at the same position as in the WMAP data, but they do not affect the cosmological parameter estimation significantly.