大学物理 ›› 2015, Vol. 34 ›› Issue (9): 12-12.

• 著者文摘 • 上一篇    下一篇

弗里德曼模型中静态宇宙条件的两个等效解法

余恒   

  1. 北京师范大学天文系,北京100875
  • 出版日期:2015-09-25 发布日期:2015-09-20

Two equivalent solutions to the static universe condition of Friedmann model

  • Online:2015-09-25 Published:2015-09-20

摘要: 弗里德曼模型是描述当前宇宙的标准模型.其中静态宇宙条件下的物质密度和宇宙常数密度解析关系,对应于无大爆炸区的边界,是宇宙学领域的一个经典问题.经典解法从弗里德曼方程出发,通过消除高斯曲率和标度因子,获得物质密度和宇宙常数密度的相关方程,然后解出.整个推导过程较为曲折复杂.本文给出了一种简单便捷的等效方法.新方法利用哈勃常数的表达式,根据基本物理量的实际取值范围,将问题转化为数学极值问题,从而获得解决.

关键词: 弗里德曼模型, 静态宇宙条件, 无大爆炸区, 物质密度, 宇宙学常数密度

Abstract: In the standard universe model Friedmann model, the analytic relation between mass density and cosmological constant density of the static universe condition is a basic relation, which defines the No-Big-Bang region. The classical solution derives the relation by eliminating the curvature and scale factor from the Friedmann equation. The whole process is complex, We find an equivalent solution which can reach the same result easier. The new solution converts this question into a mathematical extreme problem by considering the value range of physical parameters and makes the process more directly.

Key words: Friedmann model, static universe condition, No Big Band region, mass density, cosmological constant density

中图分类号: 

  • P159