A Mathematical Aspect of FRW - Cosmological Models Varying t and Λ

In this paper discussing about the mathematical aspect of variables such as cosmological constant (Λ) and gravitational constant (G) under some suitable assumptions, G(t)=F exp(3Hγt) (where is constant and γ is equation of state parameter), and the cosmological constant. Λ∞t-2 The exact solutions for the field equations and discuss some physical properties of the cosmological model. An expanding universe is found by using a relation between Friedmann equation and an equation of state. The cosmological constant has been involved on several occasions to correct some seemingly real difficulty with the cosmological predictions of standard general relativity. The most notable of these where its initial use by Einstein to produce static universe. The physical situation regarding is unclear. The other cosmological parameters Hubble constant (H), the density parameter (ρ), Gravitational constant (G) etc, may not constant at all. In this work emphasize to investigate these constants vary with time.