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Is it possible to express Einstein field equations of general relativity in terms of invariants of Riemann tensor and Stress-energy tensor?
I suppose field equations should lead to an algebraic relation between them, but I find it very difficult to find anything on the invariants themselves, let alone on their application to GR, in books that I have and even in google.
If someone could either point me to a good book or some article? Or maybe it's just obvious/impossible to do and I'm missing something.