Constraints on the Cosmic Expansion Rate at Redshift 2.3 from the Lyman-α Forest

Andrei Cuceu; Andreu Font-Ribera; Seshadri Nadathur; Benjamin Joachimi; Paul Martini

doi:10.1103/PhysRevLett.130.191003

Constraints on the Cosmic Expansion Rate at Redshift 2.3 from the Lyman-α Forest

Phys Rev Lett. 2023 May 12;130(19):191003. doi: 10.1103/PhysRevLett.130.191003.

Authors

Andrei Cuceu^{1

2

3

4}, Andreu Font-Ribera^{4

5}, Seshadri Nadathur⁶, Benjamin Joachimi⁴, Paul Martini^{1

2}

Affiliations

¹ Center for Cosmology and Astro-Particle Physics, The Ohio State University, Columbus, Ohio 43210, USA.
² Department of Astronomy, The Ohio State University, Columbus, Ohio 43210, USA.
³ Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA.
⁴ Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom.
⁵ Institut de Física d'Altes Energies, The Barcelona Institute of Science and Technology, Campus UAB, 08193 Bellaterra (Barcelona), Spain.
⁶ Institute of Cosmology and Gravitation, University of Portsmouth, Burnaby Road, Portsmouth, PO1 3FX, United Kingdom.

PMID: 37243628
DOI: 10.1103/PhysRevLett.130.191003

Abstract

We determine the product of the expansion rate and angular-diameter distance at redshift z=2.3 from the anisotropy of Lyman-α (Lyα) forest correlations measured by the Sloan Digital Sky Survey (SDSS). Our result is the most precise from large-scale structure at z>1. Using the flat Λ cold dark matter model we determine the matter density to be Ω_{m}=0.36_{-0.04}^{+0.03} from Lyα alone. This is a factor of 2 tighter than baryon acoustic oscillation results from the same data due to our use of a wide range of scales (25<r<180 h^{-1} Mpc). Using a nucleosynthesis prior, we measure the Hubble constant to be H_{0}=63.2±2.5 km/s/Mpc. In combination with other SDSS tracers, we find H_{0}=67.2±0.9 km/s/Mpc and measure the dark energy equation-of-state parameter to be w=-0.90±0.12. Our Letter opens a new avenue for constraining cosmology at high redshift.