- #1
ehrenfest
- 2,020
- 1
Homework Statement
Zwiebach claims that differentiating 12.12, which is
[tex]X^I (\tau, \sigma) X^J(\tau, \sigma')-X^J(\tau, \sigma') X^I(\tau, \sigma) = 0[/tex]
w.r.t. tau gives the same commutator with everything dotted. I think that is downright wrong. If you use the product rule to write everything out, it just doesn't work out.