Vasanthi, M. M.Padmanabhan, T.2012-03-042012-03-041985-12-11http://hdl.handle.net/11007/252Cosmological scenario with massive unstable neutrinos are discussed. Restrictions on the mass and lifetime of the unstable neutrino are derived from (a) age and mass density of the universe and (b) the growth of primordial fluctuations. It will not be possible to accommodate unstable neutrinos with masses above ~ `1 keV in standard cosmology unless they have exceedingly small lifetimeenNeutrinoUnstable-cosmologyKinematical constraintsArticle