Measuring cosmological parameters with a luminosity-time correlation of gamma-ray bursts

TL;DR

This study uses gamma-ray bursts with plateau phases to measure cosmological parameters, employing a luminosity-time correlation to extend the Hubble diagram to high redshifts and constrain cosmological models.

Contribution

It introduces a method to standardize GRBs with plateau phases using the $L_0$-$t_b$ correlation and mitigates circularity issues with Gaussian process, providing new constraints on cosmological parameters.

Findings

Estimated matter density parameter $\, ext{Omega}_m$ around 0.33.

Consistent results with the $\, ext{Lambda CDM}$ model.

Supports the importance of selecting GRBs from the same physical mechanism.

Abstract

Gamma-ray bursts (GRBs), as a possible probe to extend the Hubble diagram to high redshifts, have attracted much attention recently. In this paper, we select two samples of GRBs that have a plateau phase in X-ray afterglow. One is short GRBs with plateau phases dominated by magnetic dipole (MD) radiations. The other is long GRBs with gravitational-wave (GW) dominated plateau phases. These GRBs can be well standardized using the correlation between the plateau luminosity $L_0$ and the end time of plateau $t_b$. The so-called circularity problem is mitigated by using the observational Hubble parameter data and Gaussian process method. The calibrated \ltb ~correlations are also used to constrain $\Lambda$CDM and $w(z)$ = $w_{0}$ models. Combining the MD-LGRBs sample from Wang et al. (2021) and the MD-SGRBs sample, we find $\Omega_{m} = 0.33_{-0.09}^{+0.06}$ and $\Omega_{\Lambda}$ = $1.06_{-0.34}^{+0.15}$ excluding systematic uncertainties in the nonflat $\Lambda$CDM model. Adding type Ia supernovae from Pantheon sample, the best-fitting results are $w_{0}$ = $-1.11_{-0.15}^{+0.11}$ and $\Omega_{m}$ = $0.34_{-0.04}^{+0.05}$ in the $w=w_0$ model. These results are in agreement with the $\Lambda$CDM model. Our result supports that selection of GRBs from the same physical mechanism is crucial for cosmological purposes.