Upper panel: perturbed surface density for the models with a Jupiter and an Earth. The location of the low-mass planets are marked with + and × signs. Because the surface density perturbation is identical in both cases, we only show the surface density map of one of them but marked the location of both planets for comparison. The red, yellow, magenta, and grey lines mark different distances from the planets’ orbit. The dashed lines belong to the model with the low-mass planet at × and the solid lines are for the one with planet at +. These lines are also added to the lower panel to denote the effect of the Jupiter’s spirals. Lower panel: same as panel a of Fig. 13. The green and blue curves show the torque on the low-mass planet initiated close to L₄ and L₅ equilibria, respectively. The scaling is the Jupiter’s Hill radius R_H for the x-axis and Γ₀ for the y-axis that is calculated using the Jupiter’s mass.