Inflation and Higgs

TL;DR

This paper reviews various Higgs inflation models, classifies them by tensor-to-scalar ratio predictions, and explores their cosmological implications, including supersymmetric extensions and potential gravitational wave signals.

Contribution

It provides a comprehensive classification of Higgs inflation models based on tensor-to-scalar ratio and investigates their cosmological consequences, including supersymmetric versions and gravitational wave predictions.

Findings

SUSY $B-L$ Higgs inflation requires SUSY breaking scale around 100 TeV.

Different models predict distinct tensor-to-scalar ratios.

Possible gravitational wave signals from collapsing domain walls.

Abstract

We briefly review several Higgs inflation models and discuss their cosmological implications. We first classify the inflation models according to the predicted value of the tensor-to-scalar ratio: (i) $r = {\cal O}(0.01-0.1)$, (ii) $r = {\cal O}(10^{-3})$, and (iii) $r \ll 10^{-3}$. For each case we study (i) the Higgs inflation with a running kinetic term, (ii) the Higgs inflation with a non-minimal coupling to gravity, and (iii) the $B-L$ Higgs inflation. In the last case we introduce supersymmetry to suppress the Coleman-Weinberg corrections for successful inflation, and derive the upper bound on the SUSY breaking scale. Interestingly, the SUSY $B-L$ Higgs inflation requires the SUSY breaking scale of order ${\cal O}(100)$\,TeV to explain the observed spectral index. We briefly discuss a topological Higgs inflation which explains the origin of the standard model near-criticality. We also mention the possibility of Higgs domain walls and the gravitational waves emitted by the collapsing domain walls.