A complete cosmological scenario from f(R, Tφ) gravity theory

Recent elaborated by Harko et al., the f(R, T) theories of gravity allow one to contemplate an optimistic alternative to dark energy, for which R and T stand for the Ricci scalar and the trace of the energy-momentum tensor, respectively. Although the literature has shown that the T dependence on the gravitational part of the action - which is due to the consideration of quantum effects - may induce some novel features in the scope of late-time cosmological dynamics, in the radiation-dominated universe, when T = 0, no contributions seem to arise from such theories. Apparently, f(R, T) contributions to a radiation-dominated universe may arise only from the f(R, T-phi) approach, which is nothing but the f(R, T) gravity in the case of a self-interacting scalar field whose trace of the energy-momentum tensor is T-phi. We intend, in this article, to show how f(R, T-phi) theories of gravity can contribute to the study of the primordial stages of the universe. Our results predict a graceful exit from an inflationary stage to a radiation-dominated era. They also predict a late-time cosmic acceleration after a matter-dominated phase, enabling the f(R, T-phi) theories to describe, in a self-consistent way, all the different stages of the dynamics of the universe.