The internal rotation of the Sun and its link to the solar Li and He surface abundances

The Sun serves as a natural reference for the modelling of the various physical processes at work in stellar interiors. Helioseismology results, which inform us on the characterization of the interior of the Sun (such as, for example, the helium abundance in its envelope), are, however, at odds with heavy element abundances. Moreover, the solar internal rotation and surface abundance of lithium have always been challenging to explain. We present results of solar models that account for transport of angular momentum and chemicals by both hydrodynamic and magnetic instabilities. We show that these transport processes reconcile the internal rotation of the Sun, its surface lithium abundance, and the helioseismic determination of the envelope helium abundance. We also show that the efficiency of the transport of chemicals required to account for the solar surface lithium abundance also predicts the correct value of helium, independently from a specific transport process.