Higher Dimensional Unified Description of Early Universe with Variable Gravitational and Cosmological Constants

In this paper we consider the five dimensional cosmological model with variable gravitational and cosmological constants in the presence of perfect fluid in Kaluza-Klein theory of gravitation. The exact solutions of the field equations are obtained by using the gamma law equation of state p=(γ−1)ρ in which the parameter γ depends on scale factor R. A unified description of early universe is presented with the assumption Λ=βH2 in which inflationary phase is followed by radiation dominated phase. The various physical aspects of the cosmological models are also discussed in the framework of higher dimensional space time.