Helioseismic constraints on the solar structure and the solar neutrino problem

The inversion of helioseismic modes leads to precise constraints on the internal structure of the Sun, which must be satisfied by the computed solar models. Including the element segregation which occurred in the Sun since its formation leads to solar models in much better agreement with the inversion structure than those which ignore it. However the observed lithium depletion cannot be explained without other effects like mild mixing below the convection zone, or rapid mass loss in the early stages of the solar evolution. In any case the models are not compatible with the observed neutrino fluxes. Mixing near the solar core, which has been invoked as a way of decreasing the neutrino production, can be infirmed by helioseismic results. These results will be discussed and solar models close to the "Seismic Sun" will be presented.