Testing the local void hypothesis using baryon acoustic oscillation measurements over the last twenty years

Understand

A promising solution to the Hubble tension is a local void that is roughly 20% underdense out to 300 Mpc, as suggested by galaxy number counts in the near-infrared.

• Gravitationally driven outflows from this KBC void might inflate redshifts enough to solve the Hubble tension, a scenario explored in detail by Haslbauer et al.
• We obtain predictions for the baryon acoustic oscillation (BAO) observables in their best-fitting void models and in the homogeneous $Planck$ cosmology.
• We compare these models against our compilation of available BAO measurements from the past twenty years.