主题：【摘译】最新提出的轮回宇宙模型或能解决宇宙常数的难题 -- 衲子

The cyclic universe gets around this problem, say Steinhardt and Turok. With cycles of growth and collapse taking a trillion years or so, and no limit to how many such cycles have preceded ours, there is plenty of time for the vacuum energy to have decayed almost to zero. And each cycle would concentrate matter during the collapse phase, making sure that the Universe doesn't end up empty.