Viewing this metric on ,
yields an isometry to a subset of Minkowski space. Consequently, is flat, and we shall refer to as the flat Kasner solution. This solution is past causally geodesically incomplete, but the curvature is clearly bounded. Furthermore, it is extendible. Considering the same solution on the torus, it is also possible to construct an extension; see, e.g., .
However, there are more sophisticated examples of pathologies. In , the authors demonstrate that given any positive integer , there is a polarized Gowdy vacuum spacetime with at least inequivalent maximal extensions.
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