Computability Superselection Rule and its physical explanation

Space- and Time-Like Superselection Rules in Conformal Quantum Field Theory

In conformally invariant quantum field theories one encounters besides the standard DHR superselection theory based on spacelike (Einstein-causal) commutation relations and their Haag duality another timelike (''Huygens'') based superselection structure. Whereas the DHR theory based on spacelike causality of observables confirmed the Lagrangian internal symmetry picture on the level of the physical principles of local quantum physics, the attempts to understand the timelike based superselection charges (associated with the center of the conformal covering group) in terms of timelike localized …