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Accepted · first revision · record

Title: Do TRGB, JAGB and Cepheid ladders give the same Hubble constant?
Plain: Distances to nearby galaxies can be calibrated with pulsating stars (Cepheids), the brightest old red giant stars, or carbon-rich giant stars. These methods should agree if none has a hidden bias.
Precise: Using one JWST sample of type Ia supernova host galaxies, determine the mean distance-modulus offsets between Cepheid, tip of the red giant branch (TRGB) and J-region asymptotic giant branch (JAGB) calibrations, and the resulting h from each. An answer is each offset with uncertainty below 0.02 mag and an explanation of any nonzero offset.
Settled by: A shared, blinded JWST analysis of the same hosts by independent teams with identical supernova samples.
Kind: well-posed
Answer type: value
References: (empty)
Literature status: contested
Status note: CCHP (Freedman et al. 2025, arXiv:2408.06153) obtained $h = 0.704 \pm 0.012\,(\mathrm{stat}) \pm 0.013\,(\mathrm{sys})$ from TRGB with 24 supernova calibrators, and from JWST data alone $h = 0.688\,(\mathrm{TRGB})$ and $0.678\,(\mathrm{JAGB})$, while SH0ES reports mean method differences near $0.03\,\mathrm{mag}$ and $h$ near 0.73.
Posed since: 2019