Reconstructing the Cosmic Expansion History up to Redshift z=6.29 with the Calibrated Gamma-Ray Bursts

TL;DR

This paper calibrates gamma-ray bursts using supernova data to reconstruct the universe's expansion history up to redshift 6.29, addressing previous calibration issues and revealing new features in cosmic evolution.

Contribution

It introduces a cosmology-independent calibration of GRBs and applies a smooth reconstruction method to extend the cosmic expansion history to high redshift.

Findings

Reconstructed the expansion history up to z=6.29.

Identified new features in the cosmic expansion data.

Calibrated 70 GRBs using 307 SNIa data.

Abstract

Recently, Gamma-Ray Bursts (GRBs) were proposed to be a complementary cosmological probe to type Ia supernovae (SNIa). GRBs have been advocated to be standard candles since several empirical GRB luminosity relations were proposed as distance indicators. However, there is a so-called circularity problem in the direct use of GRBs. Recently, a new idea to calibrate GRBs in a completely cosmology independent manner has been proposed, and the circularity problem can be solved. In the present work, following the method proposed by Liang {\it et al.}, we calibrate 70 GRBs with the Amati relation using 307 SNIa. Then, following the method proposed by Shafieloo {\it et al.}, we smoothly reconstruct the cosmic expansion history up to redshift $z=6.29$ with the calibrated GRBs. We find some new features in the reconstructed results.