An Improved Treatment of Optics in the Lindquist-Wheeler Models

TL;DR

This paper improves Lindquist-Wheeler models of the universe by refining their optical treatment, resulting in models that closely match the dynamics and some observational properties of standard cosmological solutions.

Contribution

It introduces an improved construction of LW models that better reproduces both the dynamical evolution and observational distances of the universe.

Findings

Redshifts and dynamics match FLRW models within 3% up to z~2.

Angular diameter and luminosity distances differ from FLRW but align with the 'empty beam' approximation.

Improved models better replicate the properties of space-times with discrete masses.

Abstract

We consider the optical properties of Lindquist-Wheeler (LW) models of the Universe. These models consist of lattices constructed from regularly arranged discrete masses. They are akin to the Wigner-Seitz construction of solid state physics, and result in a dynamical description of the large-scale Universe in which the global expansion is given by a Friedmann-like equation. We show that if these models are constructed in a particular way then the redshifts of distant objects, as well as the dynamics of the global space-time, can be made to be in good agreement with the homogeneous and isotropic Friedmann-Lemaitre-Robertson-Walker (FLRW) solutions of Einstein's equations, at the level of <3% out to z~2. Angular diameter and luminosity distances, on the other hand, differ from those found in the corresponding FLRW models, while being consistent with the 'empty beam' approximation, together with the shearing effects due to the nearest masses. This can be compared with the large deviations found from the corresponding FLRW values obtained in a previous study that considered LW models constructed in a different way. We therefore advocate the improved LW models we consider here as useful constructions that appear to faithfully reproduce both the dynamical and observational properties of space-times containing discrete masses.