Constraints on the curvature of the Universe and dynamical dark energy from the Full-shape and BAO data

TL;DR

This paper derives constraints on the universe's curvature and dark energy properties using full-shape, BAO, BBN, and supernova data, achieving results comparable to CMB-based analyses without relying on CMB data.

Contribution

It provides CMB-independent constraints on cosmological parameters using a combination of large-scale structure and supernova data, including models with dynamical dark energy.

Findings

Spatial curvature consistent with a flat universe.

Dark energy equation of state close to a cosmological constant.

Strong constraints obtained without CMB data.

Abstract

We present limits on the parameters of the o$\Lambda$CDM, $w_0$CDM, and $w_0 w_a$CDM models obtained from the joint analysis of the full-shape, baryon acoustic oscillations (BAO), big bang nucleosynthesis (BBN) and supernovae data. Our limits are fully independent of the data on the cosmic microwave background (CMB) anisotropies, but rival the CMB constraints in terms of parameter error bars. We find the spatial curvature consistent with a flat universe $\Omega_k=-0.043_{-0.036}^{+0.036}$ ($68\%$ C.L.); the dark-energy equation of state parameter $w_0$ is measured to be $w_0=-1.031_{-0.048}^{+0.052}$ ($68\%$ C.L.), consistent with a cosmological constant. This conclusion also holds for the time-varying dark energy equation of state, for which we find $w_0=-0.98_{-0.11}^{+0.099}$ and $w_a=-0.33_{-0.48}^{+0.63}$ (both at $68\%$ C.L.). The exclusion of the supernovae data from the analysis does not significantly weaken our bounds. This shows that using a single external BBN prior, the full-shape and BAO data can provide strong CMB-independent constraints on the non-minimal cosmological models.