Variants of Kinetically Modified Non-Minimal Higgs Inflation in Supergravity

TL;DR

This paper develops variants of Higgs inflation models within supergravity, demonstrating their compatibility with recent observational data and exploring stabilization mechanisms ensuring sub-Planckian inflation with unitarity preserved.

Contribution

It introduces new kinetically modified non-minimal Higgs inflation models in supergravity with specific Kaehler potentials and analyzes their observational viability and stabilization methods.

Findings

Models match Planck and Bicep2/Keck results

Inflation occurs at sub-Planckian field values

Stabilization mechanisms maintain perturbative unitarity

Abstract

We consider models of chaotic inflation driven by the real parts of a conjugate pair of Higgs superfields involved in the spontaneous breaking of a grand unification symmetry at a scale assuming its Supersymmetric value. Employing Kaehler potentials with a prominent shift-symmetric part proportional to c- and a tiny violation, proportional to c+, included in a logarithm we show that the inflationary observables provide an excellent match to the recent Planck and Bicep2/Keck Array results setting, e.g., 0.0064<= c+/c-<1/N where N=2 or 3 is the prefactor of the logarithm. Deviations of these prefactors from their integer values above are also explored and a region where hilltop inflation occurs is localized. Moreover, we analyze two distinct possible stabilization mechanisms for the non-inflaton accompanying superfield, one tied to higher order terms and one with just quadratic terms within the argument of a logarithm with positive prefactor Ns<6. In all cases, inflation can be attained for subplanckian inflaton values with the corresponding effective theories retaining the perturbative unitarity up to the Planck scale.