Equatorial differential rotation as a function of radius when the contraction term is removed from the induction equation. Numerical solutions (runs D1–D7) are plotted in colour at Re_c = 10⁻¹ (red), Re_c = 1 (blue), and Re_c = 5 (purple), for various Lundquist numbers ranging from 10⁴ to 5 × 10⁴ (from the lightest to the darkest). For Re_c = 1, an additional simulation is presented at L_u = 5 × 10³. The curves are rescaled by Re_c then compared to the analytical solution Eq. (39) displayed in black dashed lines. The other parameters are E = 10⁻⁴, P_r(N₀/Ω₀)² = 10⁴, and P_m = 10².