Global Symmetry Evolution in Axion Cosmologies

摘要

Cosmological constraints on invisible axion models require a mass scale far below the grand unification scale. Such a hierarchy can lead to an evolution of global symmetries accompanied by a complicated axion domain wall problem. We show that if this problem is solved at the highest mass scale in the theory, then it does not reoccur at lower mass scales. Two realistic models are discussed. 19 references. (ERA citation 10:005626)