Coupling factor q as a function of the mixed-mode density . The vertical dashed lines indicate the transition from subgiants to red giants defined by Mosser et al. (2014). Triangles indicate subgiants; squares indicate stars on the RGB (small squares for long-cadence Kepler data and big squares for short-cadence data). Three values of q obtained for a synthetic 1.3-M_⊙ evolutionary sequence are also shown with × (see Sect. 5.3 and Table 3).