Higgs Portal to Inflation and Fermionic Dark Matter

TL;DR

This paper explores a model where a singlet scalar and fermionic dark matter interact via the Higgs portal, enabling inflation consistent with current cosmological observations and constrained by collider and dark matter detection data.

Contribution

It introduces a unified framework linking Higgs portal dark matter with inflation driven by either the Higgs or singlet scalar, stabilized by their mixing and dark matter interactions.

Findings

Dark matter mass is near half the Higgs or singlet scalar mass.

Inflationary predictions align with Planck data.

Model constraints from collider, relic density, and direct detection are satisfied.

Abstract

We investigate an inflationary model involving a gauge singlet scalar and fermionic dark matter. The mixing between the singlet scalar and the Higgs boson provides a portal to dark matter. The inflaton could either be the Higgs boson or the singlet scalar, and slow roll inflation is realized via its non-minimal coupling to gravity. In this setup, the effective scalar potential is stabilized by the mixing between two scalars and coupling with dark matter. We study constraints from collider searches, relic density and direct detection, and find that dark matter mass should be around half the mass of either the Higgs boson or singlet scalar. Using the renormalization group equation improved scalar potential and putting all the constraints together, we show that the inflationary observables $n_s-r$ are consistent with current Planck data.