Cosmological Dynamics of Modified Gravity With a Non-minimal Curvature-matter Coupling (1401.7429v2)

Abstract: We perform a phase space analysis of a non-minimally coupled modified gravity theory with the Lagrangian density of the form $\frac{1}{2} f_{1}(R)+[1+\lambda f_{2}(R)]{{\cal{L}}{m}}$, where $f_1(R)$ and $f_2(R)$ are arbitrary functions of the curvature scalar $R$ and ${{\cal{L}}{m}}$ is the matter Lagrangian density. We apply the dynamical system approach to this scenario in two particular models. In the first model we assume $f_1(R)=2R$ with a general form for $f_2(R)$ and set favorable values for effective equation of state parameter which is related to the several epochs of the cosmic evolution and study the critical points and their stability in each cosmic eras. In the second case, we allow the $f_1(R)$ to be an arbitrary function of $R$ and set $f_2(R)=2R$. We find the late time attractor solution for the model and show that this model has a late time accelerating epoch and an acceptable matter era.