The aim of the study is to describe the general upper limit of the age of the universe with the help of different cosmological models of the universe. Here homogeneous and isotropic assumptions of the observed universe are not strictly followed to calculate the present age of the universe....

Indian scientist Amal Kumar Raychaudhuri established ‘Raychaudhuri equation’ in 1955 to describe gravitational focusing properties in cosmology. This equation is extensively used in general relativity, quantum field theory, string theory and the theory of relativistic membranes. This paper...