Dependence of the additional viscosity (proxy for the efficiency of angular momentum redistribution) on the stellar mass in red giants in the hydrogen-shell burning phase. These values are estimated at a surface gravity of log g ∼ 3.1, or equivalently, at a mixed-mode density of 𝒩 ∼ 7. Including these values in stellar evolution models leads to core rotation rates that agree with asteroseismic constraints. The values are given in Table 1.