Left panel: map of Ndiv(ℱ_tot), where the total flux has been computed with m₁,m₂ ∈ {m_ILR,m_COR,m_OLR}. Red contours, for which Ndiv(ℱ_tot) < 0 are associated with regions from which the orbits will be depleted, whereas blue contours, for which Ndiv(ℱ_tot) > 0 correspond to regions where the value of the DF will be increased during the secular diffusion. The contours are spaced linearly between the minimum and the maximum of Ndiv(ℱ_tot). The maximum value for the positive blue contours corresponds to Ndiv(ℱ_tot) ≃ 350, while the mininum value for the negative red contours is associated with Ndiv(ℱ_tot) ≃ −250. Right panel: from Sellwood (2012) – Fig. 7, contours of the change in the DF between the time t_S12 = 1400 and t_S12 = 0, for a run with 50M particles. Similarly to the left panel, red contours correspond to negative differences, i.e. regions emptied from their orbits, while blue contours correspond to positive differences, i.e. regions where the DF has increased during the diffusion. Both of these contours are aligned with the ILR direction of m_ILR = (2,−1) in the (J_φ,J_r)-plane, corresponding to the cyan line.