Vector field theories in cosmology

TL;DR

This paper compares vector field theories in cosmology, highlighting that the Cosmic Defect theory fits observational data with fewer parameters and can be viewed as a special case of Einstein aether theories.

Contribution

It demonstrates the relative simplicity and consistency of the Cosmic Defect theory compared to other vector theories in cosmology.

Findings

Cosmic Defect theory fits observational data with minimal parameters

CD theory is a special case of Einstein aether theories

Newtonian limits of the theories are compared

Abstract

Recently proposed theories based on the cosmic presence of a vectorial field are compared and contrasted. In particular the so called Einstein aether theory is discussed in parallel with a recent proposal of a strained space-time theory (Cosmic Defect theory). We show that the latter fits reasonably well the cosmic observed data with only one, or at most two, adjustable parameters, whilst other vector theories use much more. The Newtonian limits are also compared. Finally we show that the CD theory may be considered as a special case of the aether theories, corresponding to a more compact and consistent paradigm.