核合成[Nucleosynthesis] - 达人(其实～我是卧底，来自外星)

2005/04/26 | 核合成[Nucleosynthesis]
类别(¤〖天文〗) | 评论(0) | 阅读(44) | 发表于 14:17: At t = 0, the universe was a singularity with infinite matter/energy density and zero volume. Then the Big Bang occurred.
The time s is called the heavy particle era,and is characterized by high-energy photons colliding and producing protons and neutron.
(1)

so
(2)

The time s s is called the light particle era, and is characterized by photon colliding and producing electron,
(3)

at t = 100 s, T dropped below 10 GK and He was formed.
The period is called the radiation-dominated era. It satisfies
(4)

(5)

(6)

(7)

The time t > 3000 y, is called the matter-dominated era.
(8)

(9)

(10)

(11); 0