Do the observational data favor a local void?

TL;DR

This study investigates whether a local void can explain the tension between local measurements and CMB-inferred Hubble rates, concluding that a local void alone cannot resolve this discrepancy.

Contribution

It extends previous analyses by globally fitting the Pantheon supernova sample within an inhomogeneous Lemaître-Tolman-Bondi model to assess local bias effects.

Findings

A local void cannot fully account for the Hubble tension.

The analysis strengthens the case that new physics may be needed.

Local bias effects are insufficient to reconcile measurement discrepancies.

Abstract

The increasing tension between the different local direct measurements of the Hubble expansion rate and that inferred from the Cosmic Microwave Background observation by $\Lambda$-Cold-Dark-Matter model could be a smoking gun of new physics, if not caused by either observational systematics or local bias. We generalize previous investigation on the local bias from a local void by globally fitting the Pantheon sample over all parameters in the radial profile function of a local void described by an inhomogeneous but isotropic Lema\^{i}tre-Tolman-Bondi metric with a cosmological constant. Our conclusion strengths the previous studies that the current tension on Hubble constant cannot be saved by a local void alone.