Gravity-assisted emergent Higgs mechanism in the post-inflationary epoch

Abstract

We consider a nonstandard model of gravity coupled to a neutral scalar “inflaton” as well as to [Formula: see text] iso-doublet scalar with positive mass squared and without self-interaction, and to [Formula: see text] gauge fields. The principal new ingredient is employing two alternative non-Riemannian spacetime volume-forms (covariant integration measure densities) independent of the metric. The latter have a remarkable impact — although not introducing any additional propagating degrees of freedom, their dynamics triggers a series of important features: appearance of infinitely large flat regions of the effective “inflaton” potential as well as dynamical generation of Higgs-like spontaneous symmetry breaking effective potential for the [Formula: see text] iso-doublet scalar.