英文: Because the way the dark energy density varies is dependent on the theoretical model, each theory predicts a different time for the transition point when the expansion of the universe switched from slowdown to speedup.

中文: 因为暗能量密度随时间的改变方式和理论模型有关，因此，在每个理论中，宇宙由减速过渡到加速膨胀的时间点亦不尽相同。       更详细...

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