Einstein equations give minimum and maximum limits of cosmic scale factor by considering pressure. The contraction before expansion is like the birth of a star. As in nuclear fusion stage, the temperature and pressure of the star depends on its mass, in the order of magnitude of universe mass fusion after gravitational contraction brings about […]
AbstractThe present study is aimed at investigating the validity of the generalized second law (GSL) of thermodynamics in f(R) gravity. Choosing f(R)=R+ξRμ+ζR−ν with ξ,μ,ζ, ν > 0 (following the study of Nojiri and Odintsov in 2003), we have computed the time derivatives of total entropy for various choices of scale factor pertaining to emergent, intermediate, and logamediate […]
