Impact of low ell's on large scale structure anomalies

Abstract

We scrutinize the reported lensing anomaly of the CMB by considering several phenomenological modifications of the lensing consistency parameter, A L. Considering Planck spectra alone, we find statistically significant evidence for scale dependence (`running') of A L. We then demonstrate that the anomaly is entirely driven by Planck's low multipoles, ℓ ≤ 30. When these data points are excluded, a joint analysis with several other datasets clearly favors ΛCDM over the extended ΛCDM + A L model. Not only that the lensing anomaly and low ℓ anomaly of the CMB go away in this case, but also the S 8 tension is ameliorated, and only the Hubble tension persists.