- #1
Eduard1
- 7
- 0
Dear All,
I have recently read about WKB approximation and about perturbation theory.
Both methods are applicable in the range of slowly varying potentials. What I have not understood is which is the range of applicability of one of the method compared with the other one. More precisely: are there cases when one can apply WKB but NOT the perturbation theory ? (or vice versa ?). Also it is not clear to me if one could call WKB a perturbative method or not.
I have tried to get the answer about these 2 questions by looking in some standard QM textbooks (Cohen-Tannoudji) but so far I have not found anything clear. Maybe someone from you with more QM background could give me some hints about the differences btw WKB and perturbative methods.
With all my best wishes,
Ed
I have recently read about WKB approximation and about perturbation theory.
Both methods are applicable in the range of slowly varying potentials. What I have not understood is which is the range of applicability of one of the method compared with the other one. More precisely: are there cases when one can apply WKB but NOT the perturbation theory ? (or vice versa ?). Also it is not clear to me if one could call WKB a perturbative method or not.
I have tried to get the answer about these 2 questions by looking in some standard QM textbooks (Cohen-Tannoudji) but so far I have not found anything clear. Maybe someone from you with more QM background could give me some hints about the differences btw WKB and perturbative methods.
With all my best wishes,
Ed