On the local variation of the Hubble constant

TL;DR

This study uses N-body simulations within the standard cosmological model to assess how local measurement variations of the Hubble constant are too small to account for the current discrepancy between early universe and local universe measurements.

Contribution

The paper demonstrates that local measurement variance of H_0 is negligible, confirming the discrepancy is unlikely due to local measurement effects.

Findings

Variance in H_0 measurements is too small to explain the discrepancy.

Survey geometry and observer position do not significantly affect H_0 variance.

Results are robust across different assumptions.

Abstract

We have carefully studied how local measurements of the Hubble constant, $H_0$, can be influenced by a variety of different parameters related to survey geometry, depth, and size, as well as observer position in space. Our study is based on N-body simulations of structure in the standard $\Lambda$CDM model and our conclusion is that the expected variance in measurements of $H_0$ is far too small to explain the current discrepancy between the low value of $H_0$ inferred from measurements of the cosmic microwave background (CMB) by the Planck collaboration and the value measured directly in the local universe by use of Type Ia supernovae. This conclusion is very robust and does not change with different assumptions about survey geometry and effective sky coverage or observer position in space.