  Mohanty and Samal have shown that the magnetic-moment interaction with
nucleons contributes significantly to the photon dispersion relation in a
supernova core, and with an opposite sign relative to the usual plasma effect.
Because of a numerical error they overestimated the magnetic-moment term by two
orders of magnitude, but it is still of the same order as the plasma effect. It
appears that the Cherenkov processes gamma+nu -> nu and nu -> nu+gamma remain
forbidden, but a final verdict depends on a more detailed investigation of the
dynamical magnetic susceptibility of a hot nuclear medium.
