- #1
pleasehelpmeno
- 157
- 0
Can anyone explain how to contract [itex] R_{\alpha \beta} [/itex] to [itex] R^{\rho}_{\alpha\beta\sigma} [/itex] without multiplying it by 16 i.e [itex] g^{\rho\xi}g_{\xi\sigma}[/itex] It is in a sum with other tensor products and so I obviusly can't just multiply one term by anything ither than 1.
Should [itex] \eta [/itex]'s be used although are these valid in cosmological space-times i.e [itex] dt^2 -a^2 dx^2 [/itex]
I apologise if any indices aren't in the correct order, I am self taught
Should [itex] \eta [/itex]'s be used although are these valid in cosmological space-times i.e [itex] dt^2 -a^2 dx^2 [/itex]
I apologise if any indices aren't in the correct order, I am self taught