Thanks a lot. Now I have just two short questions:
(1) In the last expression with the string of equalities, could you have expanded the bracket differently. Meaning that instead of \eta_{\mu\rho}\Lambda^\rho{}_\sigma\omega^\sigma{ }_\lambda(\Lambda^{-1})^\lambda{}_\nu , would it had been...
Can anyone explain to me why in going from (2.4.7) to (2.4.8) the indices on the LT are arranged in the way they are. Why is mu the first index (lower) and rho the second (upper)?
Could they have been arranged in any other way? From the rules that I know, they can.
The operator is completely general but I think that definition 26 would apply. But I have a few question concerning Definition 27:
1. What specifically are the Ai?
2. Doesn't the power series expansion go under the continuous spectrum? I ask this because in the discrete spectrum at least...
For a hermitian operator A, does the function f(A) have the same eigenkets as A?
This has been bothering me as I try to solve Sakurai question (1.27, part a). Some of my class fellows decided that it was so and it greatly simplifies the equations and it helps in the next part too but I don't...