what does it mean to be symmetric for tensors and Kronecker delta symbols and help explain this answer to me












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i understand how to change 2 tensors into Kronecker delta symbols but unsure how they managed to transform back to just one. If someone could add all the steps to get to the answer that would be amazing :)










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  • Do you know about (anti)symmetric matrices?
    – hkBst
    Nov 27 at 17:30










  • no but I do know about matrices in general
    – complexityyy
    Nov 27 at 17:53


















0














enter image description here



i understand how to change 2 tensors into Kronecker delta symbols but unsure how they managed to transform back to just one. If someone could add all the steps to get to the answer that would be amazing :)










share|cite|improve this question






















  • Do you know about (anti)symmetric matrices?
    – hkBst
    Nov 27 at 17:30










  • no but I do know about matrices in general
    – complexityyy
    Nov 27 at 17:53
















0












0








0







enter image description here



i understand how to change 2 tensors into Kronecker delta symbols but unsure how they managed to transform back to just one. If someone could add all the steps to get to the answer that would be amazing :)










share|cite|improve this question













enter image description here



i understand how to change 2 tensors into Kronecker delta symbols but unsure how they managed to transform back to just one. If someone could add all the steps to get to the answer that would be amazing :)







tensor-products tensors tensor-decomposition kronecker-delta






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asked Nov 27 at 17:23









complexityyy

407




407












  • Do you know about (anti)symmetric matrices?
    – hkBst
    Nov 27 at 17:30










  • no but I do know about matrices in general
    – complexityyy
    Nov 27 at 17:53




















  • Do you know about (anti)symmetric matrices?
    – hkBst
    Nov 27 at 17:30










  • no but I do know about matrices in general
    – complexityyy
    Nov 27 at 17:53


















Do you know about (anti)symmetric matrices?
– hkBst
Nov 27 at 17:30




Do you know about (anti)symmetric matrices?
– hkBst
Nov 27 at 17:30












no but I do know about matrices in general
– complexityyy
Nov 27 at 17:53






no but I do know about matrices in general
– complexityyy
Nov 27 at 17:53












1 Answer
1






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oldest

votes


















1














By the replacement property:
begin{align*}
(delta_{ad}delta_{be}-delta_{ae}delta_{bd})varepsilon_{efa}
&=delta_{ad}delta_{be}varepsilon_{efa}-delta_{ae}delta_{bd}varepsilon_{efa} \
&=delta_{be}varepsilon_{efd}-delta_{bd}varepsilon_{afa} \
&=varepsilon_{bfd}-0,
end{align*}

since, if an index is repeated, the Levi-Civita symbol is zero.






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  • thank you so much!
    – complexityyy
    Nov 27 at 17:52










  • You're welcome!
    – Adrian Keister
    Nov 27 at 17:54











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1 Answer
1






active

oldest

votes








1 Answer
1






active

oldest

votes









active

oldest

votes






active

oldest

votes









1














By the replacement property:
begin{align*}
(delta_{ad}delta_{be}-delta_{ae}delta_{bd})varepsilon_{efa}
&=delta_{ad}delta_{be}varepsilon_{efa}-delta_{ae}delta_{bd}varepsilon_{efa} \
&=delta_{be}varepsilon_{efd}-delta_{bd}varepsilon_{afa} \
&=varepsilon_{bfd}-0,
end{align*}

since, if an index is repeated, the Levi-Civita symbol is zero.






share|cite|improve this answer





















  • thank you so much!
    – complexityyy
    Nov 27 at 17:52










  • You're welcome!
    – Adrian Keister
    Nov 27 at 17:54
















1














By the replacement property:
begin{align*}
(delta_{ad}delta_{be}-delta_{ae}delta_{bd})varepsilon_{efa}
&=delta_{ad}delta_{be}varepsilon_{efa}-delta_{ae}delta_{bd}varepsilon_{efa} \
&=delta_{be}varepsilon_{efd}-delta_{bd}varepsilon_{afa} \
&=varepsilon_{bfd}-0,
end{align*}

since, if an index is repeated, the Levi-Civita symbol is zero.






share|cite|improve this answer





















  • thank you so much!
    – complexityyy
    Nov 27 at 17:52










  • You're welcome!
    – Adrian Keister
    Nov 27 at 17:54














1












1








1






By the replacement property:
begin{align*}
(delta_{ad}delta_{be}-delta_{ae}delta_{bd})varepsilon_{efa}
&=delta_{ad}delta_{be}varepsilon_{efa}-delta_{ae}delta_{bd}varepsilon_{efa} \
&=delta_{be}varepsilon_{efd}-delta_{bd}varepsilon_{afa} \
&=varepsilon_{bfd}-0,
end{align*}

since, if an index is repeated, the Levi-Civita symbol is zero.






share|cite|improve this answer












By the replacement property:
begin{align*}
(delta_{ad}delta_{be}-delta_{ae}delta_{bd})varepsilon_{efa}
&=delta_{ad}delta_{be}varepsilon_{efa}-delta_{ae}delta_{bd}varepsilon_{efa} \
&=delta_{be}varepsilon_{efd}-delta_{bd}varepsilon_{afa} \
&=varepsilon_{bfd}-0,
end{align*}

since, if an index is repeated, the Levi-Civita symbol is zero.







share|cite|improve this answer












share|cite|improve this answer



share|cite|improve this answer










answered Nov 27 at 17:30









Adrian Keister

4,77351933




4,77351933












  • thank you so much!
    – complexityyy
    Nov 27 at 17:52










  • You're welcome!
    – Adrian Keister
    Nov 27 at 17:54


















  • thank you so much!
    – complexityyy
    Nov 27 at 17:52










  • You're welcome!
    – Adrian Keister
    Nov 27 at 17:54
















thank you so much!
– complexityyy
Nov 27 at 17:52




thank you so much!
– complexityyy
Nov 27 at 17:52












You're welcome!
– Adrian Keister
Nov 27 at 17:54




You're welcome!
– Adrian Keister
Nov 27 at 17:54


















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