Rates of specific kinetic energy diffusion, ⟨ΔE⟩, as a function of the azimuthal velocity, v_ϕ. The rates are evaluated from Eqs. (A.7) and (A.3) for two values of the stellar velocity dispersion, σ_⋆ : 20km s¹ (in black or grey); and 10 km s¹ (in blue or skyblue). A) Setting M_• = 1 × 10⁷ M_⊙, with M_•/m_⋆ ≃ 10³, the figure graphs each quadratic component and the first-order parallel one (v_∥ ⟨Δv_∥⟩, dark solid lines; we note that it has the same sign as RΩ − v_ϕ). B) The same but for a BH with M_• = 1 × 10⁸ M_⊙ (M_•/m_star ≃ 10⁴). The much higher inertia of the BH leads to a ten-fold increase in the parallel term but only subtle differences in the diffusion (quadratic) ones. The light and dotted-blue curves peak off scale in either case. The (central) angular velocity Ω = 0.05/Myr is such that RΩ ≈ 70km s¹ at R = 1.5kpc, a good match to the circular velocity at that radius.