Is ##\eta## Referring to the Minkowski Metric in Tensor Summation?

[sunrah]

sorry solved

 

[Geofleur]

By $\eta$ are you referring to the Minkowski metric? Also, I assume that only indices that appear once raised and once lowered are being summed over, so that $\eta^{ii}$ is not to be summed, correct?

 

[sunrah]

By $\eta$ are you referring to the Minkowski metric? Also, I assume that only indices that appear once raised and once lowered are being summed over, so that $\eta^{ii}$ is not to be summed, correct?

thanks, the issue was simply that sometimes I forget we are dealing with components and not whole vectors, matrices etc.