The rigorously correct expectation values can be computed from Eq. (10) adn compared with the approximation (2). In general there are terms given in Eq. (7), leading to a very rich spectrum. Only one of these terms has been used so far.
The rigorously correct expectation values can be computed from Eq. (10) adn compared with the approximation (2). In general there are terms given in Eq. (7), leading to a very rich spectrum. Only one of these terms has been used so far.