Anisotropic Multiverse with Varying c and G and Study of Its Thermodynamics

Abstract

We assume the anisotropic model of the Universe in the framework of a varying speed of light c and a varying gravitational constant G theories and study different types of singularities. We write the scale factors for the singularity models in terms of cosmic time and find some conditions for possible singularities. For future singularities, we assume the forms of a varying speed of light and varying gravitational constant. For regularizing the Big Bang singularity, we assume two forms of scale factors: the sine model and the tangent model. For both models, we examine the validity of null and strong energy conditions. Starting from the first law of thermodynamics, we study the thermodynamic behaviors of a number n of universes (i.e., multiverse) for (i) varying c, (ii) varying G and (iii) varying both c and G models. We find the total entropies for all the cases in the anisotropic multiverse model. We also find the nature of the multiverse if the total entropy is constant.