English

Current data are consistent with flat spatial hypersurfaces in the $\Lambda$CDM cosmological model but favor more lensing than the model predicts

Cosmology and Nongalactic Astrophysics 2023-03-29 v2 General Relativity and Quantum Cosmology

Abstract

We study the performance of three pairs of tilted Λ\LambdaCDM cosmological models, two pairs allowing for non-flat spatial hypersurfaces with CMB temperature and polarization power spectrum data (P18) from Planck, P18 lensing (lensing), and non-CMB data (non-CMB). For the six models, we measure cosmological parameters and study whether or not pairs of the data sets are mutually consistent in these models. Half of these models allow the lensing consistency parameter ALA_L to be an additional free parameter, while the other three have AL=1A_L = 1. The tilted spatially-flat models assume the usual primordial spatial inhomogeneity power spectrum. The tilted non-flat models assume either the primordial power spectrum used in the Planck group analyses [Planck P(q)P(q)] or a recently computed power spectrum [new P(q)P(q)]. In the tilted non-flat models with AL=1A_L=1 we find differences between P18 data and non-CMB data cosmological parameter constraints, which are large enough to rule out the Planck P(q)P(q) model at 3σ\sigma but not the new P(q)P(q) model. While both P18 data and non-CMB data separately favor a closed geometry when P18+non-CMB data are jointly analyzed the evidence in favor of non-flat hypersurfaces subsides. Differences between P18 data and non-CMB data cosmological constraints subside when ALA_L is allowed to vary. From the most restrictive P18+lensing+non-CMB data combination we get almost model-independent constraints and find that the AL>1A_L>1 option is preferred over the Ωk<0\Omega_k<0 one, with the ALA_L parameter, for all models, being larger than unity by 2.5σ\sim 2.5\sigma. According to the deviance information criterion, in the P18+lensing+non-CMB analysis, the varying ALA_L option is on the verge of being strongly favored over the AL=1A_L=1 one, which could indicate a problem for the standard tilted flat Λ\LambdaCDM model (Abridged abstract).

Keywords

Cite

@article{arxiv.2211.04268,
  title  = {Current data are consistent with flat spatial hypersurfaces in the $\Lambda$CDM cosmological model but favor more lensing than the model predicts},
  author = {Javier de Cruz Perez and Chan-Gyung Park and Bharat Ratra},
  journal= {arXiv preprint arXiv:2211.04268},
  year   = {2023}
}

Comments

83 pages, 39 figures. PRD accepted version, minor changes only