Quick question about the EFE's. When writing the einstein tensor [itex]G_{\mu\nu}=R_{\mu\nu}-\frac{1}{2}Rg_{\mu\nu}[/itex], and using the definition of the Ricci scalar [itex]R=g^{\mu\nu}R_{\mu\nu}[/itex], how does this not give you problems when you expand out [itex]R[/itex] so that the second term becomes [itex]-\frac{1}{2}g^{\mu\nu}R_{\mu\nu}g_{\mu\nu}=-2R_{\mu\nu}[/itex] when evaluating the trace, giving you the EFE's as [itex]R_{\mu\nu}=-4πGT_{\mu\nu}[/itex]?(adsbygoogle = window.adsbygoogle || []).push({});

Any help would be appreciated.

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# EFE's question regarding Ricci scalar

**Physics Forums | Science Articles, Homework Help, Discussion**