New Higgs inflation in a no-scale supersymmetric SU(5) GUT

Abstract

Higgs inflation is attractive because it identifies inflaton with the electroweak Higgs boson. In this work, we construct a new class of supersymmetric Higgs inflationary models in no-scale supergravity with an SU(5) grand unified theory (GUT) group. Extending the no-scale K\"ahler potential and SU(5) GUT superpotential, we derive a generic potential for Higgs inflation that includes the quadratic monomial potential and a Starobinsky-type potential as special limits. This type of models can accommodate a wide range of the tensor-to-scalar ratio $r=\mathcal{O}({10}^{\ensuremath{-}3}\ensuremath{-}{10}^{\ensuremath{-}1})$ as well as a scalar spectral index ${n}_{s}\ensuremath{\sim}0.96$.