Evolution of the z_max and the radial and vertical frequencies along the Sun’s L_z-level. Top: amplitude of the vertical oscillation of stars as a function of the initial Galactocentric distance. The initial values of V_φ are chosen along the Sun’s L_z-level, while z = 0 and V_Z = 20 km s⁻¹. Bottom: dynamical spectrum of the stellar orbits calculated along the Sun’s L_z-level. The nominal positions of some resonances are shown by vertical dashed lines.