If the Ricci scalar R happens to be zero (everywhere according to our metric), is that the definition of a 'flat' space time?(adsbygoogle = window.adsbygoogle || []).push({});

And how are flat space times related to Minkowski space precisely? ARE they the SR space exactly?

Thanks. Just trying to understand why 'flat space time' is a definition worth having around.

(It's nice that R is actually a scalar (like, invariant) I suppose. Since like, it doesn't matter if we switch to a 'bent' metric to represent the universe - R isn't affected)

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# Curvature (Ricci things)

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