In core-collapse supernovae, neutrinos and antineutrinos are initially
subject to significant self-interactions induced by weak neutral currents,
which may induce strong-coupling effects on the flavor evolution (collective
transitions). The interpretation of the effects is simplified when self-induced
collective transitions are decoupled from ordinary matter oscillations, as for
the matter density profile that we discuss. In this case, approximate
analytical tools can be used (pendulum analogy, swap of energy spectra). For
inverted neutrino mass hierarchy, the sequence of effects involves:
synchronization, bipolar oscillations, and spectral split. Our simulations
shows that the main features of these regimes are not altered when passing from
simplified (angle-averaged) treatments to full, multi-angle numerical
experiments.Comment: Proceedings of NO-VE 2008, IV International Workshop on "Neutrino
Oscillations in Venice" (Venice, Italy, April 15-18, 2008), edited by M.
Baldo Ceolin (University of Padova publication, Papergraf Editions, Padova,
Italy, 2008), pages 233-24
