A stable fiat universe with variable cosmological constant in f (R, T) gravity

摘要

In this paper,a general FRW cosmological model has been constructed in f(R,T) gravity reconstruction with variable cosmological constant.A number of solutions to the field equations has been generated by utilizing a form for the Hubble parameter that leads to Berman's law of constant deceleration parameter q =m-1.The possible decelerating and accelerating solutions have been investigated.For (q ＞ 0) we get a stable flat decelerating radiation-dominated universe at q =1.For (q ＜ 0) we get a stable accelerating solution describing a flat universe with positive energy density and negative cosmological constant.Nonconventional mechanisms that are expected to address the late-time acceleration with negative cosmological constant have been discussed.