  We consider the unconventional way to interpret the current data on solar
neutrino oscillations as derived recently by Halprin and Leung from a string
model based on the existence of the string dilaton field which remains massless
in the low-energy world. The equivalence principle violation entailed by the
existence of a massless dilaton may then produce neutrino oscillations even for
neutrinos that are degenerate in mass. Here we calculate the medium-induced
mass squared difference for solar neutrinos, which is due to their coherent
interactions with the cosmic neutrino background and with solar plasma
constituents. We show that this difference can naturally be large enough to
satisfy the known experimental limits on the Just So solution as well as on the
MSW solution of the solar neutrino problem.
