Probing Cosmology with 92 Localized Fast Radio Bursts and DESI BAO

TL;DR

This study uses 92 localized fast radio bursts combined with DESI BAO, CMB, and supernova data to investigate dark energy properties and measure the Hubble constant, revealing potential deviations from the standard cosmological model.

Contribution

It introduces the use of localized FRBs with existing cosmological data to constrain dark energy parameters and Hubble constant, highlighting the importance of Galactic dispersion measure modeling.

Findings

DDE remains preferred over CDM without CMB data.

Joint analysis constrains dark energy EoS parameters with  significance.

FRB-based H0 estimates depend on Galactic electron density models.

Abstract

Recent baryon acoustic oscillation (BAO) measurements from the Dark Energy Spectroscopic Instrument (DESI) collaboration, combined with the cosmic microwave background (CMB) and type Ia supernovae (SNe Ia) observations, suggest a preference for dynamical dark energy (DDE) with $w_0>-1$ and $w_a<0$. Given the cosmological origin of fast radio bursts (FRBs), the combination of their dispersion measures and host galaxy redshifts makes localized FRBs a valuable tool for probing cosmology. Using an updated sample of 92 localized FRBs, along with DESI BAO, PlantheonPlus and CMB data, we constrain the dark energy (DE) equation of state (EoS) under the Chevallier-Polarski-Linder (CPL) parameterization. We find that even without incorporating CMB data, DDE remains preferred with $w_0 = -0.855 ^{+0.084}_{-0.084}$ and $w_a = -1.174^{+0.462}_{-0.491}$ at a confidence level of $\sim2.5 \sigma$. A joint analysis constrains these to be $w_0 = -0.784^{+0.064}_{-0.064}$ and $w_a = -0.872^{+0.269}_{-0.278}$, showing a discrepancy with $\Lambda$CDM at a $\sim3.1\sigma$ level. Furthermore, using localized FRBs alone, we estimate the Hubble constant $H_0$ to be $69.04^{+2.30}_{-2.07}$ and $75.61^{+2.23}_{-2.07} \, \rm km \, s^{-1} \, Mpc^{-1}$, assuming the Galactic electron density models to be NE2001 (Cordes \& Lazio) and YMW16 (Yao et al.), respectively. Thus, accurate accounting of the Galactic dispersion measure is crucial for resolving the Hubble tension with FRBs. Future BAO measurements, next-generation CMB experiments, and more localized FRBs will further constrain the DE EoS and the cosmological parameters.