Comparison of the Hubble Tension Measurement from Two Approaches: Distance Ladder and CMB

Shuowen Qian

2025

Abstract

The Hubble Tension arose when two distinct values of the Hubble constant were calculated, which implied either experimental flaw, or a fundamental misunderstanding of the universe. This study provides an overview of the mathematical meaning of the Hubble constant using Hubble’s Law, as well as the Hubble parameter by interpreting the terms in the Friedmann Equation. The distance ladder method will also be elaborated; by explaining the basic mechanism of the method, which is observing the absolute magnitude of the Cepheid variable stars, calibrating them with the Type la Supernovae, eventually establishing a correlation where distance increases linearly with velocity, in which the Hubble constant is the constant of proportionality. The CMB method will be explained particularly with the underlying features of CMB that enable this method: the BAO and the sound horizon, which is integrated into the method of inputting observed values from the angular power spectrum into the ΛCDM to generate Hubble constant. Comparisons, limitations, of the two methods will be addressed, such as the interference to observation by the metallicity of Cepheids dense star-forming regions, the reliance on Cepheids of the Type la Supernovae in the distance ladder method. The sensitive dependence on the ΛCDM model; as well as the potential incompleteness of the model for the CMB method. A further discussion of the scientific meaning of Hubble tension will also be provided.

Paper Citation

in Harvard Style

Qian S. (2025). Comparison of the Hubble Tension Measurement from Two Approaches: Distance Ladder and CMB. In Proceedings of the 2nd International Conference on Innovations in Applied Mathematics, Physics, and Astronomy - Volume 1: IAMPA; ISBN 978-989-758-774-0, SciTePress, pages 240-245. DOI: 10.5220/0013822800004708

in Bibtex Style

@conference{iampa25,
author={Shuowen Qian},
title={Comparison of the Hubble Tension Measurement from Two Approaches: Distance Ladder and CMB},
booktitle={Proceedings of the 2nd International Conference on Innovations in Applied Mathematics, Physics, and Astronomy - Volume 1: IAMPA},
year={2025},
pages={240-245},
publisher={SciTePress},
organization={INSTICC},
doi={10.5220/0013822800004708},
isbn={978-989-758-774-0},
}

in EndNote Style

TY - CONF

JO - Proceedings of the 2nd International Conference on Innovations in Applied Mathematics, Physics, and Astronomy - Volume 1: IAMPA
TI - Comparison of the Hubble Tension Measurement from Two Approaches: Distance Ladder and CMB
SN - 978-989-758-774-0
AU - Qian S.
PY - 2025
SP - 240
EP - 245
DO - 10.5220/0013822800004708
PB - SciTePress