(a) Fractional frequency difference δf_nkm/f_nkm, with δf_nkm = f_centrifugal − f_spherical and f_nkm = f_centrifugal as a function of the fractional rotation rate for n = 1 to n = 100. Calculations based on central 2 M_⊙, X_c = 0.50 MESA model with Ω/Ω_c ∈ [0.10−0.70], exhibiting prograde dipole sectoral (k, m) = (0, 1) modes. (b) Same as (a), but now with the isolated effect of the deformation of the Brunt-Väisälä frequency profile and radial coordinate (achieved by setting ). (c) Same as (a), but now with the isolated effect of the deviation of the eigenvalue of the GLTE (achieved by setting and a = r₀).