Читать книгу Quantum Mechanics, Volume 3 - Claude Cohen-Tannoudji - Страница 159

Equality (32) has the same form as relation (5) of Complement B_XV, with a simple change: the replacement of the free particle energies ek = ħ²k²/2m by the energies , which are as yet unknown. As this change does not impact the mathematical structure of the density operator, we can directly use the results of Complement B_XV.