English

Impact of Low ell's on Large Scale Structure Anomalies

Cosmology and Nongalactic Astrophysics 2025-07-23 v2 General Relativity and Quantum Cosmology High Energy Physics - Phenomenology

Abstract

We scrutinize the reported lensing anomaly of the CMB by considering several phenomenological modifications of the lensing consistency parameter, ALA_{\rm L}. Considering Planck spectra alone, we find statisically significant evidence for scale dependence (`running') of ALA_{\rm L}. We then demonstrate that the anomaly is entirely driven by Planck's low multipoles, 30\ell \leq 30. When these data points are excluded a joint analysis with several other datasets clearly favors Λ\LambdaCDM over the extended ΛCDM+AL\Lambda \rm CDM+A_L model. Not only that the lensing anomaly and low \ell anomaly of the CMB go away in this case, but also the S8S_8 tension is ameliorated, and only the Hubble tension persists.

Keywords

Cite

@article{arxiv.2409.15457,
  title  = {Impact of Low ell's on Large Scale Structure Anomalies},
  author = {Ido Ben-Dayan and Utkarsh Kumar and Meir Shimon and Amresh Verma},
  journal= {arXiv preprint arXiv:2409.15457},
  year   = {2025}
}

Comments

33 pages, 9 figures, and 8 tables. 2409.15457