Exact Results in Quantum Theory

Infrared problems in QED are related to fundamental, conceptual physical questions, such as: what is a charged particle, completeness of particle interpretation of electromagnetic field, existence of vacuum, or quantum status of long range degrees of freedom. Answers to these questions, based on locality paradigm, do not seem to be fully convincing (despite the existence of procedures for avoiding infrared infinities incalculations). This talk briefly characterizes perspectives which openwith an admission of nonlocal variables residing in infinity, or at theboundary of spacetime after compactification.Recently, this line of investigation gains popularity.