SU(5) and the Invisible Axion

Abstract
Dine, Fischler, and Srednicki have proposed a solution to the strong CP puzzle in which the mass and couplings of the axion are suppressed by an inverse power of a large mass. We construct an explicit SU(5) model in which this mass is the vacuum expectation value which breaks SU(5) down to SU(3) ⊗ SU(2) ⊗ U(1).