Does Standard Cosmology Express Cosmological Principle Faithfully?

TL;DR

This paper examines whether the standard cosmological model accurately represents the cosmological principle, highlighting potential inconsistencies in simplified 1+1 dimensional cases and questioning its fidelity in 1+3 dimensions.

Contribution

It investigates the limitations of Einstein's equations in lower dimensions and challenges the assumption that standard cosmology faithfully encodes the cosmological principle.

Findings

Einstein tensor vanishes in 1+1 dimensions, providing no evolution info.

Constructed 1+1D cosmology contradicts the standard cosmological principle.

Raises doubts about the faithful expression of the cosmological principle in 1+3D standard cosmology.

Abstract

In 1+1 dimensional case, Einstein equation cannot give us any information on the evolution of the universe because the Einstein tensor of the system is identically zero. We study such a 1+1 dimensional cosmology and find the metric of it according to cosmological principle and special relativity, but the results contradict the usual expression of cosmological principle of standard cosmology. So we doubt in 1+3 dimensional case, cosmological principle is expressed faithfully by standard cosmology.