From inflation to cosmological electroweak phase transition with a complex scalar singlet

TL;DR

This paper explores models with scalar singlets to achieve inflation, strong electroweak phase transitions, and correct dark matter relic density, highlighting the complex singlet model's advantages over the real singlet model.

Contribution

It demonstrates that the complex singlet model can simultaneously explain inflation, relic density, and electroweak phase transition, unlike the real singlet model.

Findings

Complex singlet model achieves correct relic density with specific parameters.

Electroweak phase transition can occur via a two-step process in these models.

Real singlet model cannot simultaneously explain relic density, inflation, and SFOEWPT.

Abstract

In this work, we investigate the possibility to realize inflation and strong first order electroweak phase transitions(SFOEWPT) together with the relic density explanation. We studied the usual Higgs-portal real singlet dark matter model and the global U(1) breaking complex singlet model with the pseudoscalar being dark matter candidate. We focus on higher dark matter parameter regions due to the lower dark matter masses region are almost excluded by the current direct detection experiments except that of the so-called ${\it Higgs~ funnel ~regime}$ with $m_{DM}\sim m_h/2$. In both models, the SFOEWPT can occur through two-step where the magnitude of the Higgs-singlet quartic couplings can account for the Higgs or singlet inflation. The usual Higgs-portal real singlet dark matter model can not address the correct relic density together with the explanation of inflation and SFOEWPT. With the complex singlet model, the correct relic density can also be obtained simultaneously when the mixing angle $0.1<\theta<0.2$ and the dark matter mass is $\sim800$ GeV.