- #1
mat1z
- 3
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Task: The task is to compute the commutator of L^2 with all components of the r-vector. It seems to be an unusual task for I was unable to find it in any book.
Known stuff: I know that [tex][L_i,x_j]=i \hbar \epsilon_{ijk} x_k[/tex] ([tex]\epsilon_{ijk}[/tex] being the Levi-Civita symbol). Now I would go about as follows (summation implied):
My attempt: [tex][L^2,x_j]=[L_iL_i,x_j]=L_i[L_i,x_j]+[L_i,x_j]L_i=i \hbar \epsilon_{ijk} (L_i x_k + x_k L_i)[/tex]
Question: Is this correct? Is there a physical meaning to this result other than that they do not commute (with the usual implications)?
Regards, Matti from Germany
Known stuff: I know that [tex][L_i,x_j]=i \hbar \epsilon_{ijk} x_k[/tex] ([tex]\epsilon_{ijk}[/tex] being the Levi-Civita symbol). Now I would go about as follows (summation implied):
My attempt: [tex][L^2,x_j]=[L_iL_i,x_j]=L_i[L_i,x_j]+[L_i,x_j]L_i=i \hbar \epsilon_{ijk} (L_i x_k + x_k L_i)[/tex]
Question: Is this correct? Is there a physical meaning to this result other than that they do not commute (with the usual implications)?
Regards, Matti from Germany
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