Background cosmological dynamics in f(R) gravity and observational constraints

In this paper, we carry out a study of viable cosmological models in f(R) gravity at the background level. We use observable parameters like Omega and gamma to form an autonomous system of equations and show that the models under consideration exhibit two different regimes in their time evolution, namely, a phantom phase followed by a quintessencelike behavior. We employ state finder parameters to emphasize a characteristic discriminative signature of these models.