Thermodynamics in Variable Speed of Light Theories

Variable speed of light theories (VSL) are interesting because they could solve several cosmological puzzles. In this work we study the thermodynamics and Newtonian limit of the varying speed of light theory developed by J. Magueijo (Magueijo 2000). In the covariant and locally Lorentz invariant VSL proposed by Magueijo c is a dimensionless dynamical scalar field c=c₀ e^ψ, where c₀ is a constant. The matter and gravitational lagrangians are multiplied by the factors e^bψ and e^aψ respectively.