Troubleshooting Tensors: A Quick Fix Guide

[mahblah]

Hi... here it is... sorry for my english...

http://sphotos-c.ak.fbcdn.net/hphotos-ak-ash4/297165_4722421629188_964469850_n.jpg

 

[TSny]

Hello. Looks like you replaced A^\rho by g^{\alpha\beta}A_\beta. What happened to $\rho$ and how did $\alpha$ appear? Similarly for your indices on the partial derivative: $\sigma$ disappears while $\eta$ suddenly appears.

 

[mahblah]

Thanks Tsny, ...but it's a simply rename of the index... i mean... i think this is not the problem..

 

[dextercioby]

You can't rename free indices, only 'dummy' (ones summed over) ones.