Gravity-Assisted Emergent Higgs Mechanism in the Post-Inflationary Epoch

Abstract: We consider a non-standard model of gravity coupled to a neutral scalar "inflaton" as well as to SU(2)xU(1) iso-doublet scalar with positive mass squared and without self-interaction, and to SU(2)xU(1) gauge fields. The principal new ingredient is employing two alternative non-Riemannian space-time volume-forms (covariant integration measure densitities) 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 SU(2)xU(1) iso-doublet scalar.