Principles of Quantum Mechanics

Chapter 16

Time-dependent Perturbation Theory

16.1  INTRODUCTION

In the previous Chapter, we discussed the effects of small time-independent perturbation Ĥ′(r) on the energy eigenvalues and eigenstates of the unperturbed Hamiltonian Ĥ₀. In Chapter 7 we learnt that the stationary eigenstates of a time-independent Hamiltonian Ĥ₀ form a complete orthonormal set such that any state function ψ(r) in that space may be expressed as a linear combination ...