Thermodynamics of squared speed of sound parametrizations
Abstract
In this work, an attempt is made to study the thermodynamical analysis at the apparent horizon in the framework of fractal universe. We consider the Bekenstein entropy to examine validity of the generalized second law of thermodynamics (GSLT) and thermal equilibrium for the four different cases which are developed with the utilization of different forms of squared speed of sound. In each case, we explore the behavior of total entropy through the graphical variation of its first- and second-order derivatives with respect to redshift parameter (z). It is found that generalized second law of thermodynamics holds for Cases 1 and 2 for z>−0.1 and z>−0.2, respectively and it holds in late times as well. However, for Cases 3 and 4, this law is satisfied in early, present and future epochs. Furthermore, for Cases 1 and 2, instability of thermodynamic equilibrium is observed, but for Cases 3 and 4, it holds in the specific intervals z<−0.5 and z<−0.9, respectively.
