Supernova bounds on supersymmetric R-parity violating interactions

We reexamine resonant massless-neutrino conversions in a dense medium induced by flavour changing neutral current (FCNC) interactions. We show how the observed <(nu)over bar (e)> energy spectra from SN1987A and the supernova r-process nucleosynthesis provide constraints on supersymmetric models with R-parity violation, which are much more stringent than those obtained from the laboratory. We also suggest that resonant massless-neutrino conversions may play a positive role in supernova shock re-heating. Finally, we examine the constraints on explicit R-parity violating FCNCs in the presence of non-zero neutrino masses in the eV range, as indicated by present hot dark matter observations.