Sound-Horizon-Agnostic Forecast for Constraints on H0 and Σmν from BAO, CMB Lensing, Supernovae and LSST-like Galaxy Lensing
Abstract
We present a sound-horizon-agnostic forecast for constraints on the Hubble constant H0 and the sum of the neutrino masses Σmν from a combination of LSST-like galaxy weak lensing, Simons-Observatory-like CMB lensing, the completed DESI BAO program, and expanded supernova samples. Treating the sound horizon at baryon drag rd as a free parameter, the method provides a consistency test of ΛCDM without relying on the standard early-Universe calibration of rd. The analysis incorporates realistic galaxy weak-lensing systematics, explicitly marginalizing over photometric-redshift calibration, multiplicative shear biases, intrinsic alignments, and baryonic feedback, and extends the CMB-lensing analysis to Lmax=5000. For fixed Σmν, we forecast uncertainties of σ(H0)≃ 1.5 km/s/Mpc with our least informative prior set, σ(H0)≃ 1.3 km/s/Mpc with more restrictive priors, and σ(H0)≃ 0.7 km/s/Mpc with an additional informative prior on the amplitude of primordial fluctuations As. Allowing Σmν to vary weakens the H0 constraints, while still yielding a forecast 95% CL upper limit of about 0.4 eV on Σmν. We also clarify the scope of the rd-agnostic approach through validation tests using mock data from modified recombination and early dark energy models. The method recovers unbiased constraints on H0 for the former but not the latter, highlighting its dependence on assumptions about early-Universe physics.
Related
- Dark Energy Survey year 6 results: Cosmological constraints from galaxy clustering and weak lensing
- Fast Lensing And Sub-minute High-accuracy photometry (FLASH) with JWST: Pipeline and Primordial Black Hole Microlensing Constraints from M31
- Constraints with CMB lensing on dark matter decays to massive decay products
- UNIONS-3500 Weak Lensing: III. 2D Cosmological Constraints in Configuration Space
- Joint Model-independent Constraints on the Post-Newtonian Parameter and Cosmic Curvature from Galaxy-scale Strong Lensing, SNe Ia, BAO, and Cosmic Chronometers
BibTeX
@misc{mirpoorian2026soundhorizonagnostic,
title = {{Sound-Horizon-Agnostic Forecast for Constraints on $H_0$ and $Σm_ν$ from BAO, CMB Lensing, Supernovae and LSST-like Galaxy Lensing}},
author = {Seyed Hamidreza Mirpoorian and Helena García Escudero and Levon Pogosian and Amy Wayland and David Alonso},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.31660},
eprint = {2610.31660},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.31660},
}
RIS
TY - UNPB
TI - Sound-Horizon-Agnostic Forecast for Constraints on H_0 and Σm_ν from BAO, CMB Lensing, Supernovae and LSST-like Galaxy Lensing
AU - Seyed Hamidreza Mirpoorian
AU - Helena García Escudero
AU - Levon Pogosian
AU - Amy Wayland
AU - David Alonso
PY - 2026
DA - 2026/10/22
PB - arXiv
DO - 10.48550/arxiv.2610.31660
UR - https://arxiv.org/abs/2610.31660
AB - We present a sound-horizon-agnostic forecast for constraints on the Hubble constant H_0 and the sum of the neutrino masses Σm_ν from a combination of LSST-like galaxy weak lensing, Simons-Observatory-like CMB lensing, the completed DESI BAO program, and expanded supernova samples. Treating the sound horizon at baryon drag r_d as a free parameter, the method provides a consistency test of ΛCDM without relying on the standard early-Universe calibration of r_d. The analysis incorporates realistic galaxy weak-lensing systematics, explicitly marginalizing over photometric-redshift calibration, multiplicative shear biases, intrinsic alignments, and baryonic feedback, and extends the CMB-lensing analysis to L_max=5000. For fixed Σm_ν, we forecast uncertainties of σ(H_0)≃ 1.5 km/s/Mpc with our least informative prior set, σ(H_0)≃ 1.3 km/s/Mpc with more restrictive priors, and σ(H_0)≃ 0.7 km/s/Mpc with an additional informative prior on the amplitude of primordial fluctuations A_s. Allowing Σm_ν to vary weakens the H_0 constraints, while still yielding a forecast 95% CL upper limit of about 0.4 eV on Σm_ν. We also clarify the scope of the r_d-agnostic approach through validation tests using mock data from modified recombination and early dark energy models. The method recovers unbiased constraints on H_0 for the former but not the latter, highlighting its dependence on assumptions about early-Universe physics.
ER -