SU(2,1) / (SU(2) x U(1)) B-L Higgs Inflation

TL;DR

This paper develops a Higgs inflation model within Supergravity using a specific Kaehler potential with a pole in the kinetic term, achieving compatibility with observational data and exploring parameter tuning and modifications.

Contribution

It introduces a novel Supergravity Higgs inflation model based on an SU(2,1)/ (SU(2) x U(1)) manifold with a pole in the kinetic term, and analyzes tuning and modifications for observational consistency.

Findings

Inflationary observables compatible with data when nonrenormalizable term coefficient is finely tuned.

Modifying the Kaehler potential allows for inflation with only renormalizable superpotential terms.

Higher tensor-to-scalar ratios achieved as N approaches 80.

Abstract

We present a realization of Higgs inflation within Supergravity which is largely tied to the existence of a pole of order two in the kinetic term of the inflaton field. This pole arises due to the selected Kaehler potential which parameterizes the SU(2,1) / (SU(2) x U(1)) manifold with scalar curvature R_{21}=-6/N. The associated superpotential includes, in addition to the Higgs superfields, a stabilizer superfield, respects a B-L gauge and an R symmetries and contains the first allowed nonrenormalizable term. If the coefficient of this term is almost equal to that of the others within about 10^-5 and N=2, the inflationary observables can be done compatible with the present data. The tuning can be eluded if we modify the Kaehler potential associated with the manifold above. In this case, inflation can be realized with just renormalizable superpotential terms and results to higher tensor-to-scalar ratios as N approaches its maximum at N~80.