Rotation period evolution from the main sequence to the giant branch as a function of the (J − H)_C3 index. The models are shown for [Fe/H] = 0 and 1 M_⊙. The dashed line represents the rotation period evolution for a solid-body model. The solid line represents the computed model with differential rotation. Open circles represent subgiants with masses of about one solar mass and rotational periods determined from the rotation-activity relation by Lovis et al. (2011). Asterisk as in Fig. 3.