Energy Conditions in a Generalized Second-Order Scalar-Tensor Gravity

Figure 2

Plots (a) and (b) show WEC versus parameters 𝜔 and 𝛽 for 𝐻₀=0.718 and 𝑞₀=−0.64.

(a) 𝜌^eff+𝑝^eff≥0

(b) 𝜌^eff≥0 (𝑉₀≥0)