Study on cosmic evolution and dynamics of a flat FLRW matter-dominated universe with a specified form of dynamical Cosmological Constant term

Abstract

We have investigated a cosmological model of matter-dominated universe with a specified form of dynamic cosmological Λ-term, varying as Λ = lH + (l + λ) H2 + ½ηρ where l, λ and η are constants. We study the aforesaid cosmological model as an explanation for the accelerated expansion of the universe and obtain constraints on various model parameters for the estimation of the present values of cosmological parameters e.g.deceleration parameter, equation of state parameter, age of the universe. We also investigate the statefinder parameter {r, s}. In order to investigate stability of the system, we have treated the system in terms of dynamical system theory and studied dynamical properties and investigated critical points. By performing corresponding critical points analysis we have investigated different eras in the course of evolution of the universe.