Instability map in the cold disc case for μ₃₃ = 1.5. Left: outburst amplitude defined as A = Ṁ_max/Ṁ_tr. Here, Ṁ_c = 2.8 × 10¹⁶ g s⁻¹. Right: logarithm of the recurrence time measured in days. Black areas correspond to stability. Regions labelled ‘RI’ and ‘RII’ correspond to the magnetic gating instability; the dwarf nova instability occurs in the region labelled ‘DN’, and a thermal instability due to the dissociation of the hydrogen molecule occurs in the region labelled ‘TI’.