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Juan R.

- 416

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**complete and rigorous**derivation of Newtonian limit from GR but i found none. I suspect that it does not exist!

I do not refer to that "supposed derivation" that appears in many textbooks of GR. I refer to a rigorous and unambigous derivation of Newtonian mechanics from first principles of GR.

Please do not cite Cartan-like derivation, because that one obtains there is a modified (geomtrized) version of Newtonian mechanics after using additional asumptions like the "island asumption" used by Ehlers, etc.

**I refer to derive the exact Newtonian mechanics from GR alone.**

Please do not cite usual textbooks. It is true that Wald manual is more rigorous that others books on the topic. Wald, for example, clearly states that Newtonian mechanics does not follow from GR in the linear regime,

*since one needs, in rigor, higher order terms outside of the linear regime*. In the strict linear regime there is no gravity and motion of test particle is free. In the linear regime there is not Newtonian gravity even if many textbooks claim the contrary.

I said this in a reply to pmb_phy in the photon's mass thread and he/she replied "wrong". I write that because if pmb_phy or any other guy think that i say is "wrong" would read Wald p.78 about derivation of Newtonian limit first

... but, strictly speaking, we went beyond the linear approximation to show this.

before reply here.

Thanks in advance!