Many Worlds and Quantum Field Theory

[bhobba]

I have been meaning to ask this one for a while - but never seem to get around to it.

In MW its sometimes said it's simply the working out of the universal wave-function via Schroedinger's Equation. Of course Schroedinger's Equation is only valid non-relativistically.

Wallace doesn't really consider it - although he considers NRQM in Fock Space. And I have read where its trivial to relativise MW.

Maybe I am missing something, but it doesn't seem that trivial to me.

Thanks
Bill

 

[Demystifier]

Even if there is no wave function in QFT, there is a quantum state (in the Hilbert space) in QFT. And usually (except perhaps in quantum gravity described by the Wheeler-DeWitt equation), this state is time dependent and satisfies a functional Schrödinger equation, which is associated with the field Hamiltonian derived from the field action. So obviously, MWI in QFT refers to this time-dependent state.

 

[atyy]

But rigourously speaking, does the Schroedinger picture exist for relativistic QFT?

As far as I understand, most of the rigourous QFTs (no UV cutoff, infinite volume) are constructed using the Wightman axioms, which is more the Heisenberg picture.

I tried looking up whether the Schroedinger picture can exist for rigourous relativistic QFT, and the work seems much more recent, eg. Urs Schreiber, AQFT from n-functorial QFT, http://arxiv.org/abs/0806.1079.

 

[Demystifier]

rigourous QFTs (no UV cutoff, infinite volume)

I wonder, is there any evidence that such rigorous QFT is in agreement with observations? (Perhaps vanhees71 could say something about that.)