Model-independent and reconstruction-free evidence for cosmic acceleration from DESI baryon acoustic oscillations
Abstract
While there is ample evidence that the universe's expansion is accelerating, most of this evidence relies on assuming a shape of the relative expansion rate, H(z)/H0, informed by a cosmological model or a kinematical approach. Model-independent analyses are common for supernova datasets but rarely applied to other data. In this work, we use uncalibrated baryon acoustic oscillations (BAO) from DESI DR2 for a model-independent test of acceleration, which makes no assumptions about the theory of gravity or the energy content of the universe. We test for cosmic acceleration with three model-independent statistics that rely purely on the measured Alcock-Paczyński parameter, the isotropic BAO, and the line-of-sight BAO, and do not require any reconstruction between redshift bins unlike previous analyses. Accounting for the look-elsewhere effect, among all statistics we find 2.4σ - 4.1σ evidence for cosmic acceleration within 0 ≤ z ≤ 0.934 when assuming flatness; allowing for spatial curvature, |Ωk| ≤ 1, at least two of the three statistics retain 2.4σ - 3.5σ.
Related
- NERV: Neural-network Enhanced Reconstruction of the UniVerse with Application to Baryon Acoustic Oscillations in the BOSS DR12 Galaxy Sample
- Little Red Dot Cosmology: A Matter-Era Baryon Acoustic Oscillations Probe of ΛCDM
- Joint Constraints on the Hubble Constant and Cosmic Baryon Density from Localized Fast Radio Bursts and DESI DR2 Baryon Acoustic Oscillations
- Probing Minihalos in the Late Dark Ages through Velocity Acoustic Oscillations in the 21-cm Power Spectrum
- Baryon Acoustic Oscillations from the C iv Forest with DESI DR2
BibTeX
@misc{herold2026modelindependent,
title = {{Model-independent and reconstruction-free evidence for cosmic acceleration from DESI baryon acoustic oscillations}},
author = {Laura Herold and Graeme E. Addison and Adam G. Riess},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.40785},
eprint = {2610.40785},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.40785},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Model-independent and reconstruction-free evidence for cosmic acceleration from DESI baryon acoustic oscillations
AU - Laura Herold
AU - Graeme E. Addison
AU - Adam G. Riess
PY - 2026
DA - 2026/10/29
PB - arXiv
DO - 10.48550/arxiv.2610.40785
UR - https://arxiv.org/abs/2610.40785
AB - While there is ample evidence that the universe's expansion is accelerating, most of this evidence relies on assuming a shape of the relative expansion rate, H(z)/H_0, informed by a cosmological model or a kinematical approach. Model-independent analyses are common for supernova datasets but rarely applied to other data. In this work, we use uncalibrated baryon acoustic oscillations (BAO) from DESI DR2 for a model-independent test of acceleration, which makes no assumptions about the theory of gravity or the energy content of the universe. We test for cosmic acceleration with three model-independent statistics that rely purely on the measured Alcock-Paczyński parameter, the isotropic BAO, and the line-of-sight BAO, and do not require any reconstruction between redshift bins unlike previous analyses. Accounting for the look-elsewhere effect, among all statistics we find 2.4σ - 4.1σ evidence for cosmic acceleration within 0 ≤ z ≤ 0.934 when assuming flatness; allowing for spatial curvature, |Ω_k| ≤ 1, at least two of the three statistics retain 2.4σ - 3.5σ.
ER -