Events · Journal Talk

Journal Talk 25: Syed A. Uddin et al. (2024)

New measurements of the Hubble constant from the Carnegie Supernova Project using Cepheid, TRGB, and SBF distance calibrations to Type Ia supernovae, presented by the paper's lead author.

Carnegie Supernova Project I and II: Measurements of H₀ Using Cepheid, Tip of the Red Giant Branch, and Surface Brightness Fluctuation Distance Calibration to Type Ia Supernovae

Abstract

Direct measurements of the local Hubble constant () using Type Ia supernovae (SNe Ia) yield values that are significantly higher than those inferred from the Cosmic Microwave Background (CMB), posing a notable challenge to the standard CDM cosmological model. In this work, I present new results from the Carnegie Supernova Project, where we determine across both optical and near-infrared bandpasses (). We calibrate SN Ia luminosities using three independent distance indicators: Cepheid variables, Tip of the Red Giant Branch (TRGB) stars, and galaxy surface brightness fluctuations (SBF). By combining all calibrators, we obtain km s Mpc in the band and km s Mpc in the band. These values lessen the currently reported early- vs late-Universe tension when compared at the level of statistical uncertainties alone.

Normalized probability distributions of the Hubble constant, comparing this work's B-band and H-band measurements with Riess et al. 2022, Freedman et al. 2021, Garnavich et al. 2022, Khetan et al. 2021, and the Planck 2018 CMB value.
Figure 9 of Syed A. Uddin et al. (2024): measured in this work from the band (blue) and band (red), compared with other published late-Universe measurements and the early-Universe Planck CMB value (black). © The Authors, CC BY 4.0.

Link: https://doi.org/10.3847/1538-4357/ad3e63 (ApJ 970, 72)

Presenter: Syed Ashraf Uddin, PhD (Core Member of CASSA; Associate Professor, Department of Physical Sciences, Independent University, Bangladesh) — lead author of the paper, written as part of the Carnegie Supernova Project.

← All events