- #1
Physicist97
- 31
- 4
Say you have a scalar ##S=A^{\alpha}_{\beta}B^{\beta}_{\alpha}## . Since this just means to sum over ##{\alpha}## and ##{\beta}## , is it allowable to rewrite it as ##S=A^{\alpha}_{\alpha}B^{\beta}_{\beta}## . I don't see anything wrong with this, I simply rewrote the dummy indices, but since I am not by far an expert I would like some confirmation.