Types of quantum field thories
In principle, a pure state in classical mechanics specifies completely all information about the state of the system, while a mixed state is a probability measure on the space of pure states. This space of pure states my be identified with the state space? in Lagrangian mechanics or with the phase space in Hamiltonian mechanics.
We give a definition in a very general context.
positivity for all we have .
|classical mechanics||semiclassical approximation||…||formal deformation quantization||quantum mechanics|
|order of Planck's constant|
|states||classical state||semiclassical state||quantum state|
|observables||classical observable||quantum observable|