Modulus of the squared Brunt-Väisälä frequency, |N²|, for the 0.5 M_⊙ model (top) and the 1 M_⊙ model (bottom). Regions where N² ≥ 0 are in gray, and regions where N² < 0 are in red. The squared Coriolis frequency, 4Ω², is indicated by the horizontal dashed line for the slow (orange), the intermediate (yellow), and the fast (blue) cases, while the horizontal dotted lines correspond to 2Ω². The propagation region of gravito-inertial waves as a function of frequency is highlighted by the hatched areas (orange dots and blue hatches for the slow and fast cases, respectively).