Analyzing H(z) Data using Two-point Diagnostics

Understand

Measurements of the Hubble constant H(z) are increasingly being used to test the expansion rate predicted by various cosmological models.

• But the recent application of 2-point diagnostics, such as Om(z_i,z_j) and Omh^2(z_i,z_j), has produced considerable tension between LCDM's predictions and several observations, with other models faring even worse.
• Part of this problem is attributable to the continued mixing of truly model-independent measurements using the cosmic-chronomter approach, and model-dependent data extracted from BAOs.
• In this paper, we advance the use of 2-point diagnostics beyond their current status, and introduce new variations, which we call Delta h(z_i,z_j), that are more useful for model comparisons.