- #1

kof9595995

- 679

- 2

In classical mechanics we can easily transform observables fro cartesian to spherical polar coordinate, but in QM it seems difficult(at least for me),for example for r=sqrt(x^2+y^2+z^2), it involves square root of operators;also,I have trouble evaluating relevant commutation relations.

Well I asked this question because I remember calculating <r> in wave mechanics, but we never introduce this kind of operator in formalism.