按作者与版本查阅
以下按已登记位置排列。出现顺序、原文引用与已登记依赖分别展示；最早位置不代表全书首次定义。
Woit · 2025-10-20
已登记出处中的最早位置：§25 · en。
来源短摘录与定位
§25 · en · machine_draft · machine-draft-not-reviewed
This method turns unitary symmetries of classical phase space into unitary representations of symmetry groups on quantum state spaces. It is explained in detail here because it applies to simple systems such as the -dimensional harmonic oscillator and will also be fundamental to our later study of quantum field theory. In that setting, the observables of interest are operators in a Lie algebra representation, built from quadratic combinations of annihilation and creation operators. They arise from the constructions in this chapter applied to unitary group actions on phase space, which is infinite-dimensional in quantum field theory.