JMessenger Posted April 2, 2012 Share Posted April 2, 2012 Is it allowed for me to ask for maths help concerning the Einstein field equations to the Newtonian gradient? I wouldn't be asking for any validation or opinion on the physical theory, only whether I have made a mathematical error. Having trouble finding anyone who can give it a review. Link to comment Share on other sites More sharing options...
CaptainPanic Posted April 2, 2012 Share Posted April 2, 2012 Sure! If you show us what you already did, and that you made some effort, then I am sure someone will help. Link to comment Share on other sites More sharing options...
JMessenger Posted April 2, 2012 Author Share Posted April 2, 2012 Hi CaptainPanic, thanks! I am treating the cosmological constant as just a constant of integration. Ignoring all physical meanings, from the fundamental theorem of calculus I should be able to derive down to two equivalent Newtonian gradients whether I have [math]\Lambda[/math]=0 or not equal to zero. [math]R_{\mu \nu}-\frac{1}{2}g_{\mu \nu}R=G_{\mu \nu}=g_{\mu \nu}\Lambda-\Pi_{\mu \nu}[/math] My full derivation is here (just looking for any help on the mathematical part, don't want to get into any arguments on the physical part) http://www.vixra.org...1203.0025v1.pdf My biggest problem is that in the book General relativity:an introduction for physicists they derive a Newtonian gradient with the cosmological constant as [math]\vec{g}=-\nabla\Phi=-\frac{GM}{r^{2}}\hat{\vec{r}}+\frac{\Lambda c^{2}r}{3}\hat{\vec{r}}[/math] which treats the cosmological constant as just a term with the correct units and opposing sign. But for my derivation I get [math]=-\frac{\Lambda_{\mathrm{vac}} c^{2}r}{6}\hat{\vec{r}}+\frac{G\rho_{\mathrm{res}}V}{r^{2}}\hat{\vec{r}}[/math]. My thoughts are that I should be getting the same denominator under the cosmological constant, but having looked through their derivation I am not sure how they end up with a 3. Link to comment Share on other sites More sharing options...
JMessenger Posted April 3, 2012 Author Share Posted April 3, 2012 Would this be better asked within a specific subforum? Link to comment Share on other sites More sharing options...
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