Magnetic Moment of Massive Neutrinos in Thermal Background

We compare the magnetic moment of neutrinos carrying different type of mass in hot and dense media. The background effects on the magnetic moment of neutrinos are shown to depend on the type of neutrino mass. We compare the magnetic moment for the same value of temperature and density for Dirac and Majorana type of neutrino. Background effects are shown to be more important in the very early universe.