MBPT machinery

Our goal now will be to present the Schrddinger equation in a different form. Let us first write it down as follows 

Let us now operate on both sides of this equation with the reduced resolvent 0 

At the same time, based on the expression for AE in perturbation theory (eq. (10.59)), we have  

These are the equations of the many botfy perturbation theory, in which the exact wave function and energy are expressed in terms of the unperturbed functions and energies plus certain corrections. The problem is that, as can be seen, these corrections involve the unknown function and unknown energy. 

Let us not despair in this situation, but try to apply an iterative technique. First substitute for i/ro in the right-hand side of (10.76) that, which most resembles i/ro, i.e. We obtain 

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Reduced Resolvent or the Almosf Inverse of MBPT Machinery Part 1 Energy Equation MBPT Machinery Part 2 Wave Function Equation BriUouin-Wigner Perturbation Theory Rayleigh-Schrodinger Perturbation Theory... 

MBPT Machinery—Part 2 Wave Function Equation... 

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