(color online) The dynamical evolution of odd parity gravitational perturbation to the R² AdS BH. Here (a) the line, the dashed, the dot–dashed, and the dotted lines correspond to l = 2, 3, 4, and 5. (b) The dotted, the dot–dashed, the dashed, and the solid lines correspond to λ = −1, −0.7, −0.5, and −0.3).