Covariance systems
arXiv:math-ph/0009031 · doi:10.1088/0305-4470/34/43/311
Abstract
We introduce new definitions of states and of representations of covariance systems. The GNS-construction is generalized to this context. It associates a representation with each state of the covariance system. Next, states are extended to states of an appropriate covariance algebra. Two applications are given. We describe a nonrelativistic quantum particle, and we give a simple description of the quantum spacetime model introduced by Doplicher et al.
latex with ams-latex, 23 pages