- #1
lichen1983312
- 85
- 2
I am confused about the contraction in the proof of the contracted Bianchi identities in
https://en.wikipedia.org/wiki/Proofs_involving_covariant_derivatives
from the step
[tex] {g^{bn}}(R_{bmn;l}^m - R_{bml;n}^m + R_{bnl;m}^m) = 0[/tex]
it seems that the following two quantities are equal
[tex]{g^{bn}}R_{bml;n}^m = R_{l;n}^n[/tex]
[tex]- {g^{bn}}R_{bnl;m}^m = R_{l;m}^m[/tex]
but I don't understand how is this done if I write them explicitly
[tex]{g^{bn}}({\nabla _n}R)_{bml}^m[/tex]
[tex]- {g^{bn}}({\nabla _m}R)_{bnl}^m[/tex]
Can anybody help me? I am new to this field and I feel there is something missing. Please help to point out.
https://en.wikipedia.org/wiki/Proofs_involving_covariant_derivatives
from the step
[tex] {g^{bn}}(R_{bmn;l}^m - R_{bml;n}^m + R_{bnl;m}^m) = 0[/tex]
it seems that the following two quantities are equal
[tex]{g^{bn}}R_{bml;n}^m = R_{l;n}^n[/tex]
[tex]- {g^{bn}}R_{bnl;m}^m = R_{l;m}^m[/tex]
but I don't understand how is this done if I write them explicitly
[tex]{g^{bn}}({\nabla _n}R)_{bml}^m[/tex]
[tex]- {g^{bn}}({\nabla _m}R)_{bnl}^m[/tex]
Can anybody help me? I am new to this field and I feel there is something missing. Please help to point out.
Last edited: