Non-minimal quartic inflation in supersymmetric SO(10)

We describe how quartic (λϕ4) inflation with non-minimal coupling to gravity is realized in realistic supersymmetric SO(10) models. In a well-motivated example the 16−16‾ Higgs multiplets, which break SO(10) to SU(5) and yield masses for the right-handed neutrinos, provide the inflaton field ϕ. Thus, leptogenesis is a natural outcome in this class of SO(10) models. Moreover, the adjoint (45-plet) Higgs also acquires a GUT scale value during inflation so that the monopole problem is evaded. The scalar spectral index ns is in good agreement with the observations and r, the tensor to scalar ratio, is predicted for realistic values of GUT parameters to be of order 10−3-10−2.