What Can Be Learned by Measuring the Fluxes of the 7-Be and the pep Solar Neutrino Lines?

Measurements of the interaction rates of the solar neutrino lines of ${}^7$Be and $pep$ can be used, independent of solar models, to test whether electron flavor is conserved, to determine survival probabilities of electron-type neutrinos at specific energies, and to test for the existence of sterile neutrinos. We present analytic descriptions of these tests. We also illustrate by numerical simulations, assuming matter-enhanced and vacuum neutrino oscillations, what measurements of solar neutrino lines can teach us about neutrino masses and mixing angles.