The oscillation probability of GeV solar neutrinos of all active species

I discuss the oscillation probability of O(GeV) neutrinos of all active fla vours produced inside the Sun and detected at the Earth. In the GeV energy regime, matter effects are potentially important both for the "1-3" system and the "1-2" system. A numerical scan of the multidimensional three-flavou r parameter space is presented. One curiosity is that in the three-flavour oscillation case P-alpha beta not equal P-beta alpha for a large portion of the parameter space, even if the MNS matrix is real. Oscillation effects c omputed here may play a large role in interpreting solar WIMP search data f rom large neutrino telescopes.