We describe a spacetime endowed with a non-metricity tensor which effectively serves as a model of a spacetime foam. We explore the consequences of the non-metricity in several $f(R)$ theories.

中文翻译：

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时空缺陷的非度量构造

我们描述了一个具有非度量张量的时空，它有效地用作时空泡沫的模型。我们探讨了几个 $f(R)$ 理论中非度量性的后果。