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

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 L0 and the end time of plateau tb. The so-called circularity problem is mitigated by using the observational Hubble parameter data and Gaussian process method. The calibrated L0 – tb correlations are also used to constrain ΛCDM and w(z) = w0 models. Combining the MD-LGRBs sample from Wang et al. (2021) and the MD-SGRBs sample, we find Ωm = 0.33 +0.06 −0.09 and ΩΛ = 1.06 +0.15 −0.34 excluding systematic uncertainties in the nonflat ΛCDM model. Adding type Ia supernovae from Pantheon sample, the best-fitting results are w0 = −1.11 −0.15 and Ωm = 0.34 +0.05 −0.04 in the w = w0 model. These results are in agreement with the ΛCDM model. Our result supports that selection of GRBs from the same physical mechanism is crucial for cosmological purposes.