Particle production and universal thermodynamics

In the present work, particle creation mechanism has been employed to the Universe as a thermodynamical system. The Universe is considered to be a spatially flat FRW model and cosmic fluid is chosen as a perfect fluid with a barotropic equation of state—p=(γ-1)ρ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$p=(\gamma -1)\rho $$\end{document}. By proper choice of the particle creation rate, expressions for the entropy and temperature have been determined at various stages of evolution of the Universe. Finally, using the deceleration parameter q as a function of the redshift parameter z based on recent observations, the particle creation rate has been evaluated and its variation at different epochs have been shown graphically.