Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

In QFT the evolution of momentum and field operators is given by $∂_0φ=i[H,φ]$ and $∂_0\pi=i[H,\pi]$.

Is it possible to derive these equations from the basic operator commutation relations or are they postulated?

Note: this is a follow-up to Canonical quantization of quantum field

share|cite|improve this question
See the "Heisenberg picture". This is just the Schrodinger equation in a different point of view. – Ron Maimon May 3 '12 at 5:33
up vote 2 down vote accepted

The basic canonical commutation relations are equal time relations, which carry no information about evolution. In the operator formalism, the Heisenberg equations of motion are postulated as evolution equations.

share|cite|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.