Sunday, October 14, 2018

general relativity - At which point of the universe $R_{mu nu}=0$ if there is a source of gravitation (point mass)



Schwarschild found his solution to Einstein's field equations for vacuum ($T_{\mu \nu}=0$) by placing a point-mass in the center of origin.


Since the Ricci tensor $R_{\mu \nu}$ and the Einstein tensor $G_{\mu \nu}$ are trace-reversed, meaning they vanish identically:


Which point of a universe with a mass in it would meet this equation: $R_{\mu \nu}=0$ (and therefore $G_{\mu \nu}=0$)?


(to make sure, infinity is not a point, i.e. if gravity is infinite than you can't find a particular point, where it vanishes down to zero due to distance)




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