Solar neutrinos and turbulent diffusion

Stellar rotation generates instabilities which have not been taken into account in classical computations of stellar evolution. In particular, these instabilities may produce turbulent diffusion with important consequences over long time scales. Thus it has been shown that the loss of angular momentum which occurs in the external stellar layers due to stellar wind and magnetic braking leads to a redistribution of angular momentum. It is shown here that there are observational and theoretical reasons to suspect that a slow diffusion process due to a mild turbulence is operating in stellar interiors. Turbulent diffusion may have important consequences for the solar neutrinos problem and the (3He/4He) ratio at the solar surface. (author)