摘要
中微子在宇宙演化过程中具有十分特殊的地位。在宇宙的轻子时期之后,中微子的数密度要比重子的数密度约大10~9倍。中微子是唯一的始终可与光子数密度相比拟的粒子。因此,中微子是否具有静止质量,将极大地影响着宇宙中的质量密度,从而影响着宇宙演化的进程。特别是,对于那些与质量密度有关的宇宙学问题,例如宇宙的封闭或开放、宇宙中的引力成团过程等等,中微子的静质量有明显的作用。
The neutrino is rather peculiar and unique in the evolution of the universe. It is always as abundant as the photon in the universe. After the lepton era, its number density would be higher than that of baryon by a factor of about 109. Hence, the rest-mass of the neutrino being non-vanishing would influence greatly the mass density and further the evolution of the universe. In particular, the rest-mass of neutrinos would have important influence on those cosmic problems related with mass density, such as the problems of whether the universe being open or not, the gravitational clustering in the universe, and so on.
出处
《物理学进展》
1982年第1期67-91,共25页
Progress In Physics
