- #1
Muthumanimaran
- 81
- 2
From the book Introduction to Quantum Mechanics by Griffiths,. In the section 6.4.1 (weak field zeeman effect) Griffiths tells that the time average value of S operator is just the projection of S onto J while finding the expectation value of J+S
$$S_{avg}=\frac{(S.J)J}{J^2}$$
How to prove this?
$$S_{avg}=\frac{(S.J)J}{J^2}$$
How to prove this?