Curvature induced late time acceleration

Abstract

We formulate a modified theory of gravity to an equivalent second order gravity theory for a Lagrangian containing R and ${\frac{1}{R}}$ terms by introducing an auxiliary variable in a spatially homogeneous and isotropic background. We present a few analytical solutions of evolution equation for the deceleration parameter q as a function of the scale factor; specially in one solution, the universe evolves continuously from q = 1 (i.e. like a radiation dominated era) to ${q= -\frac{1}{2}}$ dark energy dominated late time accelerating phase when the universe is sufficiently old. The solution is supported by numerical results.