Variable-Speed-of-Light Cosmology and Second Law of Thermodynamics

TL;DR

This paper investigates the compatibility of variable-speed-of-light cosmologies with the second law of thermodynamics, highlighting constraints on models with varying constants and relative flexibility in bimetric models.

Contribution

It provides a comparative analysis of different VSL cosmologies, emphasizing thermodynamic constraints on models with varying fundamental constants.

Findings

VSL cosmologies with varying constants are severely constrained by the second law.

Bimetric cosmological models are less constrained by thermodynamic considerations.

Thermodynamic principles impose significant limitations on certain VSL theories.

Abstract

We examine whether the cosmologies with varying speed of light (VSL) are compatible with the second law of thermodynamics. We find that the VSL cosmology with varying fundamental constant is severely constrained by the second law of thermodynamics, whereas the bimetric cosmological models are less constrained.