Constraining spatial curvature with large-scale structure

Abstract

We analyse the clustering of matter on large scales in an extension of the concordance model that allows for spatial curvature. We develop a consistent approach to curvature and wide-angle effects on the galaxy 2-point correlation function in redshift space. In particular we derive the Alcock-Paczynski distortion of fσ 8, which differs significantly from empirical models in the literature. A key innovation is the use of the 'Clustering Ratio', which probes clustering in a different way to redshift-space distortions, so that their combination delivers more powerful cosmological constraints. We use this combination to constrain cosmological parameters, without CMB information. In a curved Universe, we find that Ωm, 0=0.26± 0.04 (68% CL). When the clustering probes are combined with low-redshift background probes — BAO and SNIa — we obtain a CMB-independent constraint on curvature: Ω K, 0 = 0.0041-0.0504 +0.0500. We find no Bayesian evidence that the flat concordance model can be rejected. In addition we show that the sound horizon at decoupling is r d = 144.57 ± 2.34 Mpc, in agreement with its measurement from CMB anisotropies. As a consequence, the late-time Universe is compatible with flat ΛCDM and a standard sound horizon, leading to a small value of H 0, without assuming any CMB information. Clustering Ratio measurements produce the only low-redshift clustering data set that is not in disagreement with the CMB, and combining the two data sets we obtain Ω K, 0 = -0.023 ± 0.010.

The state of the dark energy equation of state circa 2023

“…The presence of the lensing anomaly may hold significant implications when constraining other cosmological parameters beyond the standard ΛCDM model. One notable example pertains to the curvature parameter: since more lensing is expected with a higher abundance of dark matter, the observed lensing anomaly can be recast into a preference for a closed Universe, well documented and discussed in several recent works [231,300,[306][307][308][309][310][311][312][313][314][315][316][317][318][319][320][321][322][323][324].…”

Wide-angle effects in multi-tracer power spectra with Doppler corrections

“…(A simplified and unified form of the expansions in [2] is given in [35].) The c n and cn coefficients are discussed in appendix A.…”

“…4,1 (k, q) = 15 k 2 + 7q 2 4k 5 q 2 ln k + q |k − q| − 15k 6 − 191k 4 q 2 + 265k 2 q 4 − 105q 6 2qk 4 (k − q) 3 (k + q) 3 , (D.32) I 2 4,2 (k, q) = π 2q 2 δ (k − q) − 5π 2q 3 δ (k − q) + 3π 2q 4 δ(k − q), (D.33) I 2 4,3 (k, q) = 15 3k 4 + 6q 2 k 2 + 7q 4 16k 5 q 4 ln k + q |k − q| − 45k 8 − 30k 6 q 2 − 36k 4 q 4 + 190k 2 q 6 − 105q 8 8q 3 k 4 (k − q) 3 (k + q) 3 , (D.34) 35)…”

Cosmological inference from the EFTofLSS: the eBOSS QSO full-shape analysis

“…See also ref. [112] for a work presenting CMB-independent constraints on spatial curvature from beyond the standard BAO/f σ 8 that also support a flat Universe.…”