We study the detailed process by which slow contraction smooths and flattens the universe using an improved numerical relativity code that accepts initial conditions with non-perturbative deviations from homogeneity and isotropy along two independent spatial directions. Contrary to common descriptions of the early universe, we find that the geometry first rapidly converges to an inhomogeneous, spatially-curved and anisotropic ultralocal state in which all spatial gradient contributions to the equations of motion decrease as an exponential in time to negligible values. This is followed by a second stage in which the geometry converges to a homogeneous, spatially flat and isotropic spacetime. In particular, the decay appears to follow the same history whether the entire spacetime or only parts of it are smoothed by the end of slowcontraction.

我们使用改进的数值相对论代码研究缓慢收缩使宇宙平滑和平坦的详细过程，该代码接受初始条件，沿两个独立的空间方向均质和各向同性的非微扰偏差。与早期宇宙的常见描述相反，我们发现几何首先迅速收敛到一个不均匀、空间弯曲和各向异性的超局域在这种状态下，所有空间梯度对运动方程的贡献以时间指数形式减少到可以忽略不计的值。接下来是第二阶段，在该阶段中，几何会收敛到均匀、空间平坦且各向同性的时空。特别是，无论整个时空还是其中的一部分在缓慢收缩结束时被平滑，衰变似乎都遵循相同的历史。