Nature of entropy in a scalar-tensor theory of gravity

Abstract

This work is devoted to studying the generalized nature of the entropy function in a specific form of thescalar-tensor-vector (STeVe) theory of gravity for the Friedmann–Lemaitre–Robertson–Walker (FLRW) spacetime in thestate of thermal equilibrium. For this purpose, we define an equilibrium picture of thermodynamics by making useof a suitable set of the dark energy density and dark pressure descriptions, which defines an energy-momentum tensorobeying the local energy conservation law. Furthermore, we also discuss our results numerically in order to get additionalimplications.