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

Figure 1

Plot (a) shows 𝜌^eff+𝑝^eff≥0 versus 𝛽 and 𝑀₀. Plot (b) represents 𝜌^eff≥0 versus parameters 𝛽 and 𝐵 with 𝑀₀=0.2. In both cases, we take the present values of cosmological parameters with 𝐶₁=1, 𝐶₂=2.

(a) 𝜌^eff+𝑝^eff≥0

(b) 𝜌^eff≥0