Asymptotic Microcausality: Deformations of Local Quantum Field Theory

In this paper I formulate and prove an asymptotic microcausality theorem for a broad class of nonlocal deformations of local QFT. I show that the commutator of two such nonlocal observables with spacelike-separated supports obeys a bound of microcausality. These results make precise the sense in which microcausality can be an emergent property of an underlying nonlocal UV theory and then clarify the operational content of locality in this setting in connection with Sorkin's impossible measurements problem.