Time evolution of density levels in four snapshots of the poloidal section (x,y) across the accretion torus (x = 0 is the symmetry axis). This example starts from the critical equilibrium configuration, which is perturbed at the initial moment of time. At this moment the Keplerian orbital time at the inner cusp, R = 5  GM / c², corresponds to T_Kep = 70  GM / c³. Subsequently, accretion across the inner edge takes place onto the black hole (the outer horizon is at the left side of the panel). This process proceeds in an oscillatory manner, interchanging the phases of fast and diminishing accretion rate. The plasma magnetization parameter is set to β = 25 (sub-equipartion pressure of the magnetic field), the black-hole spin a = 0.1 (slow rotation of the black hole) in this example. The same colour scale as in Fig. 1. Geometrized units are used, where the length is scaled with respect to the gravitational radius, GM / c², and time is scaled by GM / c³.