- #826

- 192

- 33

Why is it not possible for the A measurement to cause the result at B if "local observables in relativistic QFTs commute with the Hamilton density when their space-time arguments are space-like separated"? How is this proven?I use the words "local" and "non-local" only in one proper mathematical meaning, i.e., that local observables in relativistic QFTs commute with the Hamilton density when their space-time arguments are space-like separated, i.e., ##[\hat{O}(x),\hat{\mathcal{H}}(y)]=0## for ##(x-y) \cdot (x-y)<0## (west-coast convention, i.e., ##\eta_{\mu \nu}=\mathrm{diag}(1,-1,-1,-1)##. Thus there cannot be any causal connections between space-like separated events.