MJ growth rate (in Ω units) from Eq. (25) as a function of k(ν_s/Ω) for different values of the wave vector angle fixing ∂_{ln r}Ω² = − 2.5Ω² (upper panel), and for different values of the differential rotation fixing χ = 1 (lower panel), as indicated in the plot. Integration parameters are: ν_A/ν_s = 0.3 and 4πGρ₀ = 3.5Ω². For χ = 0, the curve reduces to the one associated to the standard Jeans instability, while for χ ≠ 0, a second peak arises. This effect is increased by differential rotation. The critical wavelength is discontinuous for χ = 0 and χ ≠ 0 (where it remains constant changing the value of χ).