Modeling Dark Sector in Horndeski Gravity at First-Order Formalism

Figure 1

The behavior of the solutions of equation (8): (a) for , with and (blue curve), and , with and (red curve); (b) for the same values of parameters. The inset shows the behavior of at smaller times. Particularly, , for (red curve), where does not mean the Big Bang. Instead, it means the time at which our formalism starts to describe the present phase of the Universe.

(a)

(b)