“…2a (the points are the results of numerical experiments) [16]. Similarly, in the two-velocity model, the domain of existence of steady solutions in the phase space (M 0 , α, β) is separated by the surface M 0 =M(α, β) [17]; here M 0 is determined by the frozen velocity of sound. There are no steady solutions for M 0 <M(α, β), and overdriven detonation is reached for M 0 >M(α, β).…”