7 papers
The Perfect Host: JWST Cepheid Observations in a Background-Free SN Ia Host Confirm No Bias in Hubble-Constant Measurements
Adam G. Riess, Siyang Li, Gagandeep S. Anand +8
Cycle 1 JWST observations of Cepheids in SN Ia hosts resolved their red-giant-dominated NIR backgrounds, sharply reducing crowding and showing that photometric bias in lower-resolu…
The CosmoVerse White Paper: Addressing observational tensions in cosmology with systematics and fundamental physics
Eleonora Di Valentino, Jackson Levi Said, Adam Riess +533
The standard model of cosmology has provided a good phenomenological description of a wide range of observations both at astrophysical and cosmological scales for several decades.…
The Complete Sample of Available SNe Ia Luminosity Calibrations from the TRGB Observed with either HST or JWST
Siyang Li, Adam G. Riess, Gagandeep S. Anand +4
Distance ladders which calibrate the luminosity of Type Ia supernovae (SNe Ia) currently provide the strongest constraints on the local value of H0. Recent studies from the Hubble…
JAGB 2.0: Improved Constraints on the J-region Asymptotic Giant Branch-based Hubble Constant from an Expanded Sample of JWST Observations
Siyang Li, Adam G. Riess, Daniel Scolnic +2
The J-region Asymptotic Giant Branch (JAGB) is an overdensity of stars in the near-infrared, attributed to carbon-rich asymptotic giant branch stars, and recently used as a standar…
Tip of the Red Giant Branch Distances with JWST. II. I-band Measurements in a Sample of Hosts of 10 SN Ia Match HST Cepheids
Siyang Li, Gagandeep S. Anand, Adam G. Riess +7
The Hubble Tension, a >5 sigma discrepancy between direct and indirect measurements of the Hubble constant (H0), has persisted for a decade and motivated intense scrutiny of the pa…
The Hubble constant anchor galaxy NGC 4258: metallicity and distance from blue supergiants
Rolf-Peter Kudritzki, Miguel A. Urbaneja, Fabio Bresolin +5
A quantitative spectroscopic study of blue supergiant stars in the Hubble constant anchor galaxy NGC 4258 is presented. The non-LTE analysis of Keck I telescope LRIS spectra yields…