Gauging discrete symmetries

Abstract

Recent developments in quantum gravity theory have led to the suggestion that various discrete symmetries, in particular charge-parity (CP), should be "gauged," that is, interpreted as elements of some connected Lie group. As the parity operator is related to a space-time isometry, however, it is far from clear that this suggestion has any real meaning. We give a simple geometric construction in terms of which it is meaningful to "gauge" discrete symmetries, provided that certain nontrivial conditions are satisfied by the space-time manifold, by the gauge group, and by the discrete symmetry itself. © 1995 American Institute of Physics.