A Uniform Type Ia Supernova Distance Ladder with the Zwicky Transient Facility: Absolute Calibration Based on the Tip of the Red Giant Branch (TRGB) Method

Understand

The current Cepheid-calibrated distance ladder measurement of $H_0$ is reported to be in tension with the values inferred from the cosmic microwave background (CMB), assuming standard cosmology.

• However, some tip of the red giant branch (TRGB) estimates report $H_0$ in better agreement with the CMB.
• Hence, it is critical to reduce systematic uncertainties in local measurements to understand the Hubble tension.
• In this paper, we propose a uniform distance ladder between the second and third rungs, combining SNe~Ia observed by the Zwicky Transient Facility (ZTF) with a TRGB calibration of their absolute luminosity.