- 15,612

- 5,630

Well, a priori you cannot do this unless you have a non-interacting theory. This is one of the beauties with QFT.As an aside, I'm not quite sure of the details of how a wavefunction of a multi-particle system would transform. But let's stick to single particle wavefunctions for the time being.

What I am talking about is essentially related to the wave solutions of the classical Klein-Gordon equation, which to some extent generalise the de Broglie relation when interpreted as one-particle states of the non-interacting theory.