Full-shape galaxy power spectra and the curvature tension

Abstract

ABSTRACT With recent evidence for a possible ‘curvature tension’ among early and late universe cosmological probes, Effective Field Theories of Large Scale Structure (EFTofLSS) have emerged as a promising new framework to generate constraints on Ωk that are independent of both CMB measurements, and some of the assumptions of flatness that enter into other large-scale structure analyses. In this work we use EFTofLSS to simultaneously constrain measurements from the 6dFGS, BOSS, and eBOSS catalogues, representing the most expansive full-shape investigation of curvature to date. Using the Bayesian evidence ratio our full-shape data assigns betting odds of 2:1 in favour of curvature, indicating present measurements remain broadly compatible with both flat and curved cosmological models. When our full-shape sample is combined with Planck 2018 CMB measurements, we break the geometric degeneracy and recover a joint fit on Ωk of $-0.0037^{+0.0025}_{-0.0026}$. Using the suspiciousness statistic we find evidence for a moderate tension between Planck 2018 and our suite of full-shape measurements, at a significance of $1.86 ^{+0.13}_{-0.11} \sigma$ (p ∼ 0.06 ± 0.02). These results demonstrate the usefulness of full-shape clustering measurements as a CMB independent probe of curvature in the ongoing curvature tension debate.