Evidence for a Lower Value for $H_0$ from Cosmic Chronometers Data?

Understand

An intriguing discrepancy emerging in the concordance model of cosmology is the tension between the locally measured value of the Hubble rate, and the 'global' value inferred from the cosmic microwave background (CMB).

• This could be due to systematic uncertainties when measuring $H_0$ locally, or it could be that we live in a highly unlikely Hubble bubble, or other exotic scenarios.
• We point out that the global $H_0$ can be found by extrapolating $H(z)$ data points at high-$z$ down to $z=0$.
• By doing this in a Bayesian non-parametric way we can find a model-independent value for $H_0$.