open universe meaning in English

开放宇宙
开宇宙

The size of an open universe is infinite and its geometry will be similar to a hyperbolic surface
开放宇宙是无限大的，而它的几何特性和双曲面相似。
On the other hand , if the mean density of mass - energy is too low , the universe will keep on expanding forever , resulting in an open universe
相反，若质量能量的平均密度太低的话，宇宙会无休止地膨胀下去，成为一个开放的宇宙。
In the case of an open universe , the mass density ( denoted by the greek letter omega ) is less than unity , and the universe is predicted to expand forever
在一开放的宇宙里，质量密度(以希腊字母欧米加表示)是小于平均数，且宇宙被预言永远地膨胀下去。