The Standard Model Higgs boson as the inflaton

TL;DR

The paper examines whether the Standard Model Higgs boson can drive cosmic inflation without introducing new particles by coupling it non-minimally to gravity. By transforming to the Einstein frame and reparametrizing the Higgs as a field $\chi$, the Higgs potential becomes exponentially flat at large field values, enabling slow-roll inflation and predicting $n_s \approx 0.97$ and $r \approx 0.0033$, in line with observations. The required non-minimal coupling $\xi$ is fixed by COBE normalization and scales as $\xi \sim 5\times10^4\sqrt{\lambda}$, connecting Higgs properties to cosmological perturbations. Radiative corrections, including SM loops and gravity-induced terms, do not spoil the plateau, making Higgs-driven inflation a viable, minimal-extension scenario with potential relevance to models like $\nu$MSM.

Abstract

We argue that the Higgs boson of the Standard Model can lead to inflation and produce cosmological perturbations in accordance with observations. An essential requirement is the non-minimal coupling of the Higgs scalar field to gravity; no new particle besides already present in the electroweak theory is required.

Figures (2)

• Figure 1: Effective potential in the Einstein frame.
• Figure 2: The allowed WMAP region for inflationary parameters ($r$, $n$). The green boxes are our predictions supposing 50 and 60 e-foldings of inflation. Black and white dots are predictions of usual chaotic inflation with $\lambda\phi^4$ and $m^2\phi^2$ potentials, HZ is the Harrison-Zeldovich spectrum.