Riemann tensor symmetries











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The Riemann tensor has its component expression:
$R^{mu}_{nurhosigma}=partial_{rho}Gamma^{mu}_{sigmanu}-partial_{sigma}Gamma^{mu}_{rhonu}+Gamma^{mu}_{rholambda}Gamma^{lambda}_{sigmanu}-Gamma^{mu}_{sigmalambda}Gamma^{lambda}_{rhonu}.$



It is straight forward to prove the antisymmetry of $R$ in the last two indices; but how to prove the antisymmetry in the first two ones without assuming symmetric connection/torsion-free metric?










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    Riemann tensor can be equivalently viewed as curvature 2-form $Omega$ with values in a Lie algebra $mathfrak g$ of group $G = SO(n)$. The antisymmetry in one pair comes from being a 2-form, the antisymmetry in the other pair comes from the antisymmetry of ${mathfrak so}(n)$. This holds even when the connection has torsion. But it won't neccesarily hold for non-metric connections (such as symplectic connections). en.wikipedia.org/wiki/Curvature_form
    – Marek
    Dec 12 '13 at 17:28












  • Doesn't this just fall from definition?
    – IAmNoOne
    Nov 21 at 5:24










  • $R(X,Y)Z=nabla_Y nabla_X Z - nabla_X nabla_Y Z+ nabla_{[X,Y]}Z.$ Switching $X,Y$ $R(Y,X)Z=nabla_X nabla_Y Z - nabla_Y nabla_X Z+ nabla_{[Y,X]}Z = -(nabla_Y nabla_X Z - nabla_X nabla_Y Z - nabla_{[X,Y]}Z) = -R(X,Y)Z$
    – IAmNoOne
    Nov 21 at 5:29

















up vote
5
down vote

favorite
4












The Riemann tensor has its component expression:
$R^{mu}_{nurhosigma}=partial_{rho}Gamma^{mu}_{sigmanu}-partial_{sigma}Gamma^{mu}_{rhonu}+Gamma^{mu}_{rholambda}Gamma^{lambda}_{sigmanu}-Gamma^{mu}_{sigmalambda}Gamma^{lambda}_{rhonu}.$



It is straight forward to prove the antisymmetry of $R$ in the last two indices; but how to prove the antisymmetry in the first two ones without assuming symmetric connection/torsion-free metric?










share|cite|improve this question


















  • 6




    Riemann tensor can be equivalently viewed as curvature 2-form $Omega$ with values in a Lie algebra $mathfrak g$ of group $G = SO(n)$. The antisymmetry in one pair comes from being a 2-form, the antisymmetry in the other pair comes from the antisymmetry of ${mathfrak so}(n)$. This holds even when the connection has torsion. But it won't neccesarily hold for non-metric connections (such as symplectic connections). en.wikipedia.org/wiki/Curvature_form
    – Marek
    Dec 12 '13 at 17:28












  • Doesn't this just fall from definition?
    – IAmNoOne
    Nov 21 at 5:24










  • $R(X,Y)Z=nabla_Y nabla_X Z - nabla_X nabla_Y Z+ nabla_{[X,Y]}Z.$ Switching $X,Y$ $R(Y,X)Z=nabla_X nabla_Y Z - nabla_Y nabla_X Z+ nabla_{[Y,X]}Z = -(nabla_Y nabla_X Z - nabla_X nabla_Y Z - nabla_{[X,Y]}Z) = -R(X,Y)Z$
    – IAmNoOne
    Nov 21 at 5:29















up vote
5
down vote

favorite
4









up vote
5
down vote

favorite
4






4





The Riemann tensor has its component expression:
$R^{mu}_{nurhosigma}=partial_{rho}Gamma^{mu}_{sigmanu}-partial_{sigma}Gamma^{mu}_{rhonu}+Gamma^{mu}_{rholambda}Gamma^{lambda}_{sigmanu}-Gamma^{mu}_{sigmalambda}Gamma^{lambda}_{rhonu}.$



It is straight forward to prove the antisymmetry of $R$ in the last two indices; but how to prove the antisymmetry in the first two ones without assuming symmetric connection/torsion-free metric?










share|cite|improve this question













The Riemann tensor has its component expression:
$R^{mu}_{nurhosigma}=partial_{rho}Gamma^{mu}_{sigmanu}-partial_{sigma}Gamma^{mu}_{rhonu}+Gamma^{mu}_{rholambda}Gamma^{lambda}_{sigmanu}-Gamma^{mu}_{sigmalambda}Gamma^{lambda}_{rhonu}.$



It is straight forward to prove the antisymmetry of $R$ in the last two indices; but how to prove the antisymmetry in the first two ones without assuming symmetric connection/torsion-free metric?







differential-geometry general-relativity






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asked Dec 12 '13 at 16:17









user115376

515




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  • 6




    Riemann tensor can be equivalently viewed as curvature 2-form $Omega$ with values in a Lie algebra $mathfrak g$ of group $G = SO(n)$. The antisymmetry in one pair comes from being a 2-form, the antisymmetry in the other pair comes from the antisymmetry of ${mathfrak so}(n)$. This holds even when the connection has torsion. But it won't neccesarily hold for non-metric connections (such as symplectic connections). en.wikipedia.org/wiki/Curvature_form
    – Marek
    Dec 12 '13 at 17:28












  • Doesn't this just fall from definition?
    – IAmNoOne
    Nov 21 at 5:24










  • $R(X,Y)Z=nabla_Y nabla_X Z - nabla_X nabla_Y Z+ nabla_{[X,Y]}Z.$ Switching $X,Y$ $R(Y,X)Z=nabla_X nabla_Y Z - nabla_Y nabla_X Z+ nabla_{[Y,X]}Z = -(nabla_Y nabla_X Z - nabla_X nabla_Y Z - nabla_{[X,Y]}Z) = -R(X,Y)Z$
    – IAmNoOne
    Nov 21 at 5:29
















  • 6




    Riemann tensor can be equivalently viewed as curvature 2-form $Omega$ with values in a Lie algebra $mathfrak g$ of group $G = SO(n)$. The antisymmetry in one pair comes from being a 2-form, the antisymmetry in the other pair comes from the antisymmetry of ${mathfrak so}(n)$. This holds even when the connection has torsion. But it won't neccesarily hold for non-metric connections (such as symplectic connections). en.wikipedia.org/wiki/Curvature_form
    – Marek
    Dec 12 '13 at 17:28












  • Doesn't this just fall from definition?
    – IAmNoOne
    Nov 21 at 5:24










  • $R(X,Y)Z=nabla_Y nabla_X Z - nabla_X nabla_Y Z+ nabla_{[X,Y]}Z.$ Switching $X,Y$ $R(Y,X)Z=nabla_X nabla_Y Z - nabla_Y nabla_X Z+ nabla_{[Y,X]}Z = -(nabla_Y nabla_X Z - nabla_X nabla_Y Z - nabla_{[X,Y]}Z) = -R(X,Y)Z$
    – IAmNoOne
    Nov 21 at 5:29










6




6




Riemann tensor can be equivalently viewed as curvature 2-form $Omega$ with values in a Lie algebra $mathfrak g$ of group $G = SO(n)$. The antisymmetry in one pair comes from being a 2-form, the antisymmetry in the other pair comes from the antisymmetry of ${mathfrak so}(n)$. This holds even when the connection has torsion. But it won't neccesarily hold for non-metric connections (such as symplectic connections). en.wikipedia.org/wiki/Curvature_form
– Marek
Dec 12 '13 at 17:28






Riemann tensor can be equivalently viewed as curvature 2-form $Omega$ with values in a Lie algebra $mathfrak g$ of group $G = SO(n)$. The antisymmetry in one pair comes from being a 2-form, the antisymmetry in the other pair comes from the antisymmetry of ${mathfrak so}(n)$. This holds even when the connection has torsion. But it won't neccesarily hold for non-metric connections (such as symplectic connections). en.wikipedia.org/wiki/Curvature_form
– Marek
Dec 12 '13 at 17:28














Doesn't this just fall from definition?
– IAmNoOne
Nov 21 at 5:24




Doesn't this just fall from definition?
– IAmNoOne
Nov 21 at 5:24












$R(X,Y)Z=nabla_Y nabla_X Z - nabla_X nabla_Y Z+ nabla_{[X,Y]}Z.$ Switching $X,Y$ $R(Y,X)Z=nabla_X nabla_Y Z - nabla_Y nabla_X Z+ nabla_{[Y,X]}Z = -(nabla_Y nabla_X Z - nabla_X nabla_Y Z - nabla_{[X,Y]}Z) = -R(X,Y)Z$
– IAmNoOne
Nov 21 at 5:29






$R(X,Y)Z=nabla_Y nabla_X Z - nabla_X nabla_Y Z+ nabla_{[X,Y]}Z.$ Switching $X,Y$ $R(Y,X)Z=nabla_X nabla_Y Z - nabla_Y nabla_X Z+ nabla_{[Y,X]}Z = -(nabla_Y nabla_X Z - nabla_X nabla_Y Z - nabla_{[X,Y]}Z) = -R(X,Y)Z$
– IAmNoOne
Nov 21 at 5:29












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This simple change in definition,



$$nabla_anabla_b-nabla_bnabla_a$$



for



$$nabla_anabla_b-nabla_bnabla_a+T^d_{quad{ab}}nabla_d$$



However, that the Riemann tensor with torsion is no longer symmetric under exchange of the first pair of indices with the second.






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    up vote
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    This simple change in definition,



    $$nabla_anabla_b-nabla_bnabla_a$$



    for



    $$nabla_anabla_b-nabla_bnabla_a+T^d_{quad{ab}}nabla_d$$



    However, that the Riemann tensor with torsion is no longer symmetric under exchange of the first pair of indices with the second.






    share|cite|improve this answer

























      up vote
      0
      down vote













      This simple change in definition,



      $$nabla_anabla_b-nabla_bnabla_a$$



      for



      $$nabla_anabla_b-nabla_bnabla_a+T^d_{quad{ab}}nabla_d$$



      However, that the Riemann tensor with torsion is no longer symmetric under exchange of the first pair of indices with the second.






      share|cite|improve this answer























        up vote
        0
        down vote










        up vote
        0
        down vote









        This simple change in definition,



        $$nabla_anabla_b-nabla_bnabla_a$$



        for



        $$nabla_anabla_b-nabla_bnabla_a+T^d_{quad{ab}}nabla_d$$



        However, that the Riemann tensor with torsion is no longer symmetric under exchange of the first pair of indices with the second.






        share|cite|improve this answer












        This simple change in definition,



        $$nabla_anabla_b-nabla_bnabla_a$$



        for



        $$nabla_anabla_b-nabla_bnabla_a+T^d_{quad{ab}}nabla_d$$



        However, that the Riemann tensor with torsion is no longer symmetric under exchange of the first pair of indices with the second.







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Dec 13 '13 at 15:40









        jimbo

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