WORMHOLES AND PECCEI-QUINN SYMMETRIES

We show how wormholes and Peccei-Quinn symmetries are in fact complementary in solving the strong CP problem. On the one hand, Peccei-Quinn symmetries are shown to provide us with a wormhole parameter that couples only to the QCD anomaly. This then allows us to implement the wormhole solution to the strong CP problem constructed previously by the present authors as well as by Preskill, Trivedi, and Wise. On the other hand, wormholes are shown to drive the axion mass to zero or to the wormhole scale, thus avoiding the axion-energy-density crisis in either case. © 1990 The American Physical Society.