Relation between bulge-to-total mass ratio B/T and initial disc fraction f_d(r) for r = 2.2r_d (left) and r = 3.2r_d (right). Triangles pointing up, circles, and triangles pointing down correspond to simulations with c = 5, c = 10, and c = 15, respectively. The colours correspond to different disc-to-virial mass ratios: m_d = 0.005 (green), m_d = 0.01 (black), m_d = 0.02 (blue), and m_d = 0.04 (red). Symbols with B/T = 0.01 correspond to bulgeless galaxies. They have been assigned B/T = 0.01 merely to be able to show them on a logarithmic diagram. The thick solid black lines are log-log linear least-squares fits to the symbols with B/T >  0.01. They correspond to Eqs. (18) and (19). The vertical blue lines show the critical f_d that corresponds to the α = 0.28 (equivalent to assuming ϵ = 1.1 in Eq. (1)) The coloured curves compare our results to previous models (Cole et al. 2000; Hatton et al. 2003; Shen et al. 2003; Cacciato et al. 2012).