The effect of background matter on the spin oscillations of neutrinos scattered by the supermassive black hole

We study spin oscillations of neutrinos in relativistic moving matter inside an accretion disk. These neutrinos are gravitationally scattered off a spinning Kerr black hole surrounded by a thick accretion disk. The disk can co-rotate and counter-rotate with respect to BH spin. We perform numerical simulations of the propagation of a large number of incoming test neutrinos. We briefly discuss our results.