# Contents

## Idea

In physics, an observable in the context of classical mechanics/classical field theory and in fact also in prequantum field theory is called a classical observable.

In symplectic geometry/geometric prequantum theory?, classical observables are functions on phase space, often called Hamiltonian functions. They form the Poisson algebra of classical/prequantum observables, wih the Poisson bracket Lie algebra structure.

In higher prequantum field theory these observables are refined to Hamiltonian forms/local currents and form the Poisson-bracket Lie n-algebra of local observables.

classical mechanicssemiclassical approximationformal deformation quantizationquantum mechanics
order of Planck's constant $\hbar$$\mathcal{O}(\hbar^0)$$\mathcal{O}(\hbar^1)$$\mathcal{O}(\hbar^n)$$\mathcal{O}(\hbar^\infty)$
statesclassical statesemiclassical statequantum state
observablesclassical observablequantum observable

Created on March 21, 2013 at 19:55:41. See the history of this page for a list of all contributions to it.