Decay-Produced Neutrino Hot Dark Matter

We investigate different types of neutrino hot dark matter with respect to structure formation and anisotropies in the cosmic microwave background radiation (CMBR). The possibility of neutrino hot dark matter produced through the decay of a heavier neutrino by the process ${\nu }_H\to {\nu }_L+\phi$, where $\phi$ is a scalar particle, is discussed in detail. This type of dark matter can possibly be distinguished observationally from the standard neutrino dark matter by using new CMBR data from the upcoming satellite missions MAP and PLANCK.