Suppose I want to bypass the entire Hamiltonian formulation of quantum field theory and define the theory using a path integral. Thus all I can calculate are Green's function which are time ordered products of local operators. Given only these (no expansions of the field in creation anihilation operators etc.), how can I show that the fields and local operators commute at space-like separation? [\phi(x),\phi(y)]=0, when x,y are spacelike separated?(adsbygoogle = window.adsbygoogle || []).push({});

KH

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Time ordered product vs. commutator in path integral

**Physics Forums | Science Articles, Homework Help, Discussion**