Rotation-induced lithium depletion of solar-type stars in young stellar clusters

The eddy-diffusion tensor for rotating anisotropic turbulence fields is considered in order to explain the lithium decay during the spin-down process of solar-type stars. Rotation proves to be effective in the transfer of passive tracers through the solar/stellar tachoclines, located beneath the outer convection zones and assumed to possess only horizontal turbulence fields. The transport efficacy is so high that the tachocline turbulence must not exceed a Limit of (say) 10(-(3...4)) of the rms velocity of the convection zone in order to leave the lithium surviving after Gigayears. A correlation is predicted between rotation rate and lithium abundance for (fast rotating) stars of one and the same age. It can thus be tested with the solar-type stars of young clusters such as IC 2391 and others. The public database of observational parameters confirms the existence of such a correlation, which becomes weaker for older clusters like Pleiades and Hyades.