Reconciling low and high redshift GRB luminosity correlations

Understand

The correlation between the peak spectra energy ($E_p$) and the equivalent isotropic energy ($E_{\rm iso}$) of long gamma-ray bursts (GRBs), the so-called Amati relation, is often used to constrain the high-redshift Hubble diagram.

• Assuming Lambda cold dark matter ($\Lambda$CDM) cosmology, Wang et al.
• found a $\gtrsim 3\sigma$ tension in the data-calibrated Amati coefficients between low- and high-redshift GRB samples.
• To reduce the impact of fiducial cosmology, we use the Parameterization based on cosmic Age (PAge), an almost model-independent framework to trace the cosmological expansion history.