Confirmation of the Copernican principle at Gpc radial scale and above from the kinetic Sunyaev Zel'dovich effect power spectrum

TL;DR

This paper tests the Copernican principle at Gpc scales using the kinetic Sunyaev Zel'dovich effect power spectrum, confirming the principle and ruling out certain inhomogeneous universe models as alternatives to dark energy.

Contribution

It demonstrates that violations of the Copernican principle would produce detectable anisotropic kSZ signals, providing a new observational test at large cosmological scales.

Findings

Large scale inhomogeneities would cause a detectable kSZ effect.

Observed kSZ power spectrum limits rule out void models as dark energy alternatives.

The Copernican principle is confirmed at Gpc scales.

Abstract

The Copernican principle, a cornerstone of modern cosmology, remains largely unproven at Gpc radial scale and above. Here we will show that, violations of this type will inevitably cause a first order anisotropic kinetic Sunyaev Zel'dovich (kSZ) effect. If large scale radial inhomogeneities have amplitude large enough to explain the "dark energy" phenomena, the induced kSZ power spectrum will be much larger than the ACT/SPT upper limit. This single test confirms the Copernican principle and rules out the adiabatic void model as a viable alternative to dark energy.