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 .