Scattering of neutrinos and gravitational waves in supernovae

We consider the scattering of neutrinos and gravitational waves produced in supernovae (SN) explosions. Nonlinear scattering processes lead to absorption of neutrinos by the dense plasma surrounding the core, and may contribute to reviving the stalled shock wave. We estimate that about 1-10% of the neutrino energy may be absorbed by the plasma A formalism is also presented which describes neutrino oscillations into different flavours using mode conversion techniques developed for fluids. Scattering of gravitational waves is also a possibility which may be important in the propagation and absorption of gravitational radiation. This scattering may change the expected waveform signal of gravitational waves.