Wednesday, October 30, 2024

The Hubble Constant Or The Fine Structure Constant Can Vary

According to this paper's analysis, if the fine structure constant (i.e. the coupling constant of the electromagnetic force), does not vary, the Hubble constant must change over time, but if the Hubble constant is truly constant over time, the fine structure constant must have been different in the distant past than it is today. 

A varying Hubble constant is vastly more plausible than a varying fine structure constant.
Testing possible variations in fundamental constants of nature is a crucial endeavor in observational cosmology. This paper investigates potential cosmological variations in the fine structure constant (α) through a non-parametric approach, using galaxy cluster observations as the primary cosmological probe. We employ two methodologies based on galaxy cluster gas mass fraction measurements derived from X-ray and Sunyaev-Zeldovich observations, along with luminosity distances from type Ia supernovae. We also explore how different values of the Hubble constant (H(0)) impact the variation of α across cosmic history. When using the Planck satellite's H(0) observations, a constant α is ruled out at approximately the 3σ confidence level for z≲0.5. Conversely, employing local estimates of H(0) restores agreement with a constant α.
Marcelo Ferreira, Rodrigo F. L. Holanda, Javier E. Gonzalez, L. R. Colaço, Rafael C. Nunes, "Non-parametric reconstruction of the fine structure constant with galaxy clusters" arXiv:2410.21542 (October 28, 2024) (Accepted by the The European Physical Journal C).

No comments: