  The generalized dynamics describing the propagation of neutrinos in randomly
fluctuating media is analyzed: it takes into account matter-induced,
decoherence phenomena that go beyond the standard MSW effect. A widely adopted
density fluctuation pattern is found to be physically untenable: a more general
model needs to be instead considered, leading to flavor changing effective
neutrino-matter interactions. They induce new, dissipative effects that modify
the neutrino oscillation pattern in a way amenable to a direct experimental
analysis.
