A Measurement of Hubble Constant Using Cosmographic Approach from Fast Radio Bursts and SNe Ia

Abstract

The Hubble constant $H_0$ is a crucial parameter in cosmology. However, different cosmic observations have resulted in varying posterior results for $H_0$, leading to what is known as the $H_0$ tension. In order to address this issue, it is beneficial to use other dataset to constrain $H_0$. In this paper, via the cosmographic approach based on the Friedman-Lemaitre-Robertson-Walker (FLRW) metric to the dispersion measure of the intergalactic medium ${\mathrm{DM}}_{\mathrm{IGM}}(z)$ of Fast Radio Bursts (FRBs), we obtain the Taylor expansion of $⟨{\mathrm{DM}}_{\mathrm{IGM}}(z)⟩$ in terms redshift $z$. The result for Hubble constant $H_0=65.5_{-5.4}^{+6.4}$ $\mathrm{km}{\mathrm{s}}^{-1}\mathrm{Mp}{\mathrm{c}}^{-1}$ $(68$$\%$ $C.L.)$, cosmological deceleration parameter $q_0=-0.50\pm 0.20$ and the jerk parameter $j_0=-0.1_{-2.5}^{+2.0}$ using uncalibrated Supernova Ia (SNe Ia) Pantheon dataset combined with 18 localized FRBs are obtained. To demonstrate the impact of parameter degeneracies on our analysis methods, we compare the results using three different forms of $f_{\mathrm{IGM}}(z)$ and two different prior distributions for ${\Omega }_{\mathrm{b},0}$. Then we find that the uncertainty in $H_0$ is not significantly affected by the prior range of $f_{\mathrm{IGM}}(z)$ and ${\Omega }_{\mathrm{b},0}$, but the mean value is influenced by the priors for $f_{\mathrm{IGM}}(z)$ and ${\Omega }_{\mathrm{b},0}$ due to parameter degeneracies with $H_0$. Employing $f_{\mathrm{IGM}}(z)$ that evolves with redshift, we obtain the constraints for $H_0=69.0_{-5.7}^{+6.7}$ $\mathrm{km}{\mathrm{s}}^{-1}\mathrm{Mp}{\mathrm{c}}^{-1}$. Furthermore, the mock analyses give a posterior estimation of $H_0$ with an accuracy of 4.6\% and higher precision for $q_0$ and $j_0$ in the near future.