In this paper we propose minimal Higgs inflation scenarios by non-polynomial modification of the Higgs potential. The modification is done in such a way that it creates a flat plateau for a huge range of field values at the inflationary energy scale μ≃(λ)1/4α. Assuming the perturbative Higgs quartic coupling, λ≃O(1), our model prediction for all the cosmologically relevant quantities, (ns,r,dnsk), fit extremely well with observations made by PLANCK. For both the models the inflation energy scale turned out to be μ≃(1014,1015) GeV. Considering observed central value of the scalar spectral index, ns=0.968, models predict efolding number, N=(52,47). Within a wide range of viable parameter space, we found that the prediction of tensor to scalar ratio r(≤10−5) is far below the current experimental limit. The prediction for the running of scalar spectral index, dnsk, remains very small. We also computed the background field dependent unitarity scale Λ(h), which turned out to be much larger than the aforementioned inflationary energy scale.
Maity, D. (2017). Minimal Higgs inflation. Nuclear Physics B, 919, 560–568. https://doi.org/10.1016/j.nuclphysb.2017.04.005