空间曲率 meaning in English

compound curvature
curvature of space

If the density of matter and energy in the universe is less than the critical density , the space curvature will be negative
事实上，宇宙中暗物质和暗能量的多寡决定了宇宙的几何结构。假若宇宙中的物质和能量的总密度低于临界密度，它是一个空间曲率
The space geometry is open and negatively curved as a saddle . if the density equals to the critical density exactly , the space is flat as a sheet of paper . if the density is greater than the critical density , the space geometry is closed and positively curved as a ball
为负马鞍形的开放宇宙假若密度和临界密度相等，空间曲率为零，宇宙如一张白纸般平坦假若密度高于临界密度，它则是一个空间曲率为正球形的封闭宇宙。