Period spacing (top panel) as a function of eigenfrequencies for the model discussed in Section 5.3.1. We compare the γ-modes (shown in blue) with mixed dipole modes (in red) in proximity to the observable region of the oscillation spectrum, whose ν_max is the cyan line. The black and lime lines are the same as Figure 7. Some minima in the period spacing result from mode trapping rather than the coupling between p-modes and g-modes, and not all of these minima exhibit observable amplitudes. This is further illustrated in the bottom panel, which presents the corresponding simulated PSD along with the normalised inertia of radial and non-radial modes (coloured dots connected by coloured lines).