Comparison of the density wave propagation time (lower two branches denoted as t_dyn) with the disk viscous time (upper two branches denoted as t_visc), for B0-type star isothermal (p = 0) constant viscosity model and the model with decreasing (p = 0.4) temperature profile (see Fig. 6), in dependence on radius. The disk viscous time is calculated from Eq. (24). Since the rotational velocity V_φ is adopted from the models, the graph of t_visc is cut off in the region of the rapid rotational velocity drop. The plotted values of t_dyn are adopted from the models.