A sound horizon-free measurement of H₀ in DESI 2024

Zaborowski, E.A.; Taylor, P.; Honscheid, K.; Cuceu, A.; de Mattia, A.; Huterer, D.; Krolewski, A.; Martini, P.; Ross, A.J.; To, C.; Torres, A.; Ahlen, S.; Bianchi, D.; Brooks, D.; Buckley-Geer, E.; Burtin, E.; Claybaugh, T.; Cole, S.; de la Macorra, A.; Dey, Arjun; Dey, Biprateep; Doel, P.; Ferraro, S.; Font-Ribera, A.; Forero-Romero, J.E.; Gaztañaga, E.; Gil-Marín, H.; Gutierrez, G.; Guy, J.; Hahn, C.; Howlett, C.; Juneau, S.; Kehoe, R.; Kirkby, D.; Kisner, T.; Kremin, A.; Landriau, M.; Le Guillou, L.; Levi, M.E.; Magneville, C.; Meisner, A.; Miquel, R.; Moustakas, J.; Palanque-Delabrouille, N.; Percival, W.J.; Prada, F.; Pérez-Ràfols, I.; Rossi, G.; Sanchez, E.; Schlegel, D.; Schubnell, M.; Seo, H.; Sprayberry, D.; Tarlé, G.; Weaver, B.A.; Wechsler, R.H.

Abstract

The physical size of the sound horizon at recombination is a powerful source of information for early-time measurements of the Hubble constant H₀, and many proposed solutions to the Hubble tension therefore involve modifications to this scale. In light of this, there has been growing interest in measuring H₀ independently of the sound horizon. We present the first such measurement to use data from the Dark Energy Spectroscopic Instrument (DESI), jointly analyzing the full-shape galaxy power spectra of DESI luminous red galaxies, emission line galaxies, quasars, and the bright galaxy sample, in a total of six redshift bins. Information from the sound horizon scale is removed from our constraints via a rescaling procedure at the power spectrum level, with our sound horizon-marginalized measurement being driven instead primarily by the matter-radiation equality scale. This measurement is then combined with additional sound horizon-free information from Planck+ACT CMB lensing, uncalibrated type Ia supernovae, and the DESI Lyman-α forest. We agnostically combine with the DESY5, Pantheon+, and Union3 supernova datasets, with our tightest respective constraints being H 0 = 66.7+1.7 -1.9, 67.9+1.9 -2.1, and 67.8+2.0 -2.2 km s-1 Mpc-1. This corresponds to a sub-3% sound horizon-free constraint of the Hubble constant, and is the most precise measurement of its kind to date. Even without including information from the sound horizon, our measurement is still in 2.2-3.0σ tension with SH0ES. Additionally, the consistency between our result and other measurements that do rely on the sound horizon scale provides no evidence for new early-Universe physics (e.g. early dark energy). Future DESI data releases will allow unprecedented measurements of H₀ and place strong constraints on models that use beyond-ΛCDM physics to ameliorate the Hubble tension.

Citation

Zaborowski, E. A., Taylor, P., Honscheid, K., Cuceu, A., de Mattia, A., Huterer, D., Krolewski, A., Martini, P., Ross, A. J., To, C., Torres, A., Ahlen, S., Bianchi, D., Brooks, D., Buckley-Geer, E., Burtin, E., Claybaugh, T., Cole, S., de la Macorra, A., …Wechsler, R. H. (2025). A sound horizon-free measurement of H₀ in DESI 2024. Journal of Cosmology and Astroparticle Physics, 2025(06), 020. https://doi.org/10.1088/1475-7516/2025/06/020

• Journal Article Type: Article
• Acceptance Date: May 12, 2025
• Online Publication Date: Jun 17, 2025
• Publication Date: Jun 1, 2025
• Deposit Date: Jul 30, 2025
• Publicly Available Date: Jul 30, 2025
• Journal: Journal of Cosmology and Astroparticle Physics
• Electronic ISSN: 1475-7516
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 2025
• Issue: 06
• Article Number: 020
• DOI: https://doi.org/10.1088/1475-7516/2025/06/020
• Keywords: redshift surveys, power spectrum, physics of the early universe, cosmological parameters from LSS
• Public URL: https://durham-repository.worktribe.com/output/4114574