Recent content by gastkram

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    Undergrad Strange result from Bianchi identity, me spot the error

    Well, I was right that I had done something obviously wrong :wink:
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    Undergrad Strange result from Bianchi identity, me spot the error

    Yes, I guess I claimed that every coefficient has to be zero but that's not true. Mystery solved (I hope)! Thanks!
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    Undergrad Strange result from Bianchi identity, me spot the error

    Oh, that may be it. Let me think about that for a minute.
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    Undergrad Strange result from Bianchi identity, me spot the error

    Thank you for your help! I mean that it is zero because we get $$ g_{ac}g^{ac}g^{bd}=\frac{1}{2}g^{ab}g_{ac}g^{cd} \implies \delta_a^a g^{bd}=\frac{1}{2}g^{b}_{\phantom{b}c}g^{cd}\implies D g^{bd}=\frac{1}{2}g^{bd}, $$ but the dimension is not usually one half :oops:.
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    Undergrad Strange result from Bianchi identity, me spot the error

    I have accidentally derived a very wrong result from the contracted Bianchi identity and I can't see where the error is. I'm sure it's something obvious, but I need someone to point it out to me as I've gone blind. Thanks! Start with the contracted Bianchi identity, $$ \nabla_a \left(...