Some Cosmological Implications of Hidden Sectors

TL;DR

This paper explores the cosmological effects of hidden sector scalars coupled to the Higgs, emphasizing a conformal scenario that predicts a strong first-order electroweak phase transition, with implications for gravitational waves, inflation, and dark matter.

Contribution

It provides a detailed analysis of electroweak phase transition in models with hidden scalars, highlighting their potential for baryogenesis, gravitational wave signals, and dark matter candidates.

Findings

Strong first-order electroweak phase transition predicted

Enhanced gravitational wave production potential

Viable dark matter candidate identified

Abstract

We discuss some cosmological implications of extensions of the Standard Model with hidden sector scalars coupled to the Higgs boson. We put special emphasis on the conformal case, in which the electroweak symmetry is broken radiatively with a Higgs mass above the experimental limit. Our refined analysis of the electroweak phase transition in this kind of models strengthens the prediction of a strongly first-order phase transition as required by electroweak baryogenesis. We further study gravitational wave production and the possibility of low-scale inflation as well as a viable dark matter candidate.