SNe Data Analysis in Variable Speed of Light Cosmologies without Cosmological Constant

TL;DR

This paper explores variable speed of light (VSL) cosmologies as an alternative to dark energy for explaining supernovae observations, testing models against data without a cosmological constant.

Contribution

It introduces a scale factor dependent VSL model, modifies distance calculations, and compares three VSL models with the standard flat ΛCDM model using supernova data.

Findings

VSL models can fit supernova data without dark energy

Comparison shows VSL models have different distance modulus predictions

Discussion of challenges in confirming VSL theories

Abstract

In this work, we aim to show the possibilities of the variable speed of light (VSL) theory in explaining the type Ia supernovae observations without introducing dark energy. The speed of light is assumed to be scale factor dependent, which is the most popular assumption in VSL theory. We show the modified calculation of the distance modulus, and the validity of the redshift-scale factor relation in VSL theory. Three different models of VSL are tested SNe data-sets with proper constraints on the model parameters. The comparison of the three models and flat $\Lambda$CDM in distance modulus is showed. Some basic problems and the difficulties of the confirmation of the VSL theory are also discussed