New constraints on the expansion rate at redshift 2.3 from the Lyman-$α$ forest [CEA]

http://arxiv.org/abs/2209.13942


We measure the expansion rate of the Universe at redshift $z=2.3$ from the anisotropy of Lyman-$\alpha$ (Ly$\alpha$) forest correlations measured by the Sloan Digital Sky Survey (SDSS). Our result is the most precise from large-scale structure at $z>1$. In flat $\Lambda$CDM we determine the matter density to be $\Omega_\mathrm{m}=0.36^{+0.03}_{-0.04}$ from Ly$\alpha$ alone, a factor of two tighter than baryon acoustic oscillation results from the same data. Using a nucleosynthesis prior, we measure the Hubble constant to be $H_0=63.2\pm2.5$ km/s/Mpc. In combination with other SDSS tracers, we find $H_0=67.2\pm0.9$ km/s/Mpc and measure the dark energy equation-of-state parameter to be $w=-0.90\pm0.12$. Our work opens a new avenue for constraining cosmology at high redshift.

Read this paper on arXiv…

A. Cuceu, A. Font-Ribera, S. Nadathur, et. al.
Thu, 29 Sep 22
32/70

Comments: Submitted to PRL