摘要: There are many problems in astrophysics and cosmology which the form of weak interactions, their strength or number weakly interacting particles, is very important. It possible that astronomical observations may give some information about interactions. In conventional hot big bang cosmological theory leptons with associated neutrinos influences speed expansion Universe chemical composition pre-galactic matter. The interaction, as exemplified by half-life neutron, has a similar effect. addition, interactions will determine how effectively neutrino viscosity can smooth out irregularities early Universe. Because have long mean free path, they escape from central region stars whereas photons only surface. late stages stellar evolution, luminosity often believed to be much greater than photon luminosity.