Constraints on Evolutions of Fundamental Constants from Clustering of Fast Radio Burst Dispersion Measure

Abstract

Constrained measurements of fundamental physical constants using astronomical observational data represent a powerful method for investigating potential new physics. In particular, the dispersion measure (DM) of fast radio bursts (FRBs), which probes the electron density along their propagation paths, may be influenced by the space-time variation of the fine-structure constant \(\alpha\). In this study, we analyze the cross-correlation signal between foreground galaxies and the DM of background FRBs to constrain the evolution of \(\alpha\). Assuming large-scale structure (LSS) galaxy surveys with the capabilities of the China Space Station Telescope (CSST) at \(z=0.15\) and { a mock FRB survey with \(N_{\text{FRB}}=10^5\) at \(z=0.4\), we test how well \(\alpha\) variation can be constrained}, with a standard deviation of \(\sigma(\Delta \alpha / \alpha) = 0.0007\) at \(z=0.15\). Furthermore, taking into account the nonminimal coupling between the scalar field and the electromagnetic field, the variation in \(\alpha\) can lead to the non-conservation of photon number along geodesics. This would result in a violation of the CDDR and affect the evolution of the Cosmic Microwave Background (CMB) temperature. In this work, we { obtain constraints results} on the CDDR parameter \(\eta\) and the parameter \(\beta\) governing CMB temperature evolution at \(z=0.15\), yielding \(\sigma(\eta) = 0.0004\) and \(\sigma(\beta) = 0.0006\), respectively. Finally, we relate the variation in \(\alpha\) to the time evolution of the proton-to-electron mass ratio, { reporting a standard deviation} of \(\sigma(\Delta \mu/\mu) = 0.002\) at $z=0.15$. Future FRB surveys hold significant potential for advancing our understanding of the evolution of fundamental physical constants.