Comment on ``Nontrivial Geometries: Bounds on the Curvature of the Universe''

TL;DR

This paper critiques a previous study on universe curvature, clarifying misconceptions about homogeneity, metric consistency, and the evolution of spatial curvature in cosmological models.

Contribution

It corrects the assumptions and equations used in the prior work, emphasizing the proper behavior of spatial curvature in homogeneous and isotropic universes.

Findings

The space in the previous study is not homogeneous.

The equations of motion used are inconsistent with the metric.

Spatial curvature in homogeneous isotropic models always evolves as 1/a^2.

Abstract

The paper 0705.0332v1 seeks to study the effect of non-trivial spatial curvature in homogeneous and isotropic models. We note that the space considered is not homogeneous, and that the equations of motion used are inconsistent with the metric. Also, we explain why the spatial curvature of homogeneous and isotropic spacetimes always evolves like 1/a^2, contrary to the central assumption of 0705.0332v1.